blob: eff46272c91cc5bd892d2a8720e32667cb5a978a [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
Neil Schemenauer9d50d132002-03-22 17:06:59 +00009- The optional object allocator has been enabled by default.
10
Guido van Rossum8c842552002-03-14 23:05:54 +000011- If you try to pickle an instance of a class that has __slots__ but
12 doesn't define or override __getstate__, a TypeError is now raised.
13 This is done by adding a bozo __getstate__ to the class that always
14 raises TypeError. (Before, this would appear to be pickled, but the
15 state of the slots would be lost.)
16
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000017- PyErr_Display will provide file and line information for all exceptions
18 that have an attribute print_file_and_line, not just SyntaxErrors.
19
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000020- The UTF-8 codec will now encode and decode Unicode surrogates
21 correctly and without raising exceptions for unpaired ones.
22
Neal Norwitz649b7592002-01-01 19:07:13 +000023- file.xreadlines() now raises a ValueError if the file is closed:
24 Previously, an xreadlines object was returned which would raise
25 a ValueError when the xreadlines.next() method was called.
26
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000027- posix.killpg has been added where available.
28
Neal Norwitz0c766a02002-03-27 13:03:09 +000029- sys.exit() inadvertantly allowed more than one argument.
30 An exception will now be raised if more than one argument is used.
31
Tim Petersaf8446f2001-12-21 21:36:50 +000032Extension modules
33
Tim Petersfbf74f22002-03-14 19:06:01 +000034- A security hole ("double free") was found in zlib-1.1.3, a popular
35 third party compression library used by some Python modules. The
36 hole was quickly plugged in zlib-1.1.4, and the Windows build of
37 Python now ships with zlib-1.1.4.
38
Martin v. Löwis29001ff2002-03-01 10:47:37 +000039- pwd and grp return enhanced tuples now, with symbolic field names.
40
Martin v. Löwis99866332002-03-01 10:27:01 +000041- array.array is now a type object. A new format character
42 'u' indicates Py_UNICODE arrays. For those, .tounicode and
43 .fromunicode methods are available. Arrays now support __iadd__
44 and __imul__.
45
Neal Norwitze790eae2002-01-01 21:14:12 +000046- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000047 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
48 is called.
49
Tim Petersaf8446f2001-12-21 21:36:50 +000050Library
51
Martin v. Löwis5c137c22002-03-18 12:44:08 +000052- compileall now supports quiet operation.
53
Martin v. Löwis587c98c2002-03-17 18:37:22 +000054- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
55 connections.
56
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000057- socket module: the SSL support was broken out of the main
58 _socket module C helper and placed into a new _ssl helper
59 which now gets imported by socket.py if available and working.
60
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000061- encodings package: added aliases for all supported IANA character
62 sets
63
Guido van Rossum606fe4e2001-12-28 20:57:14 +000064- ftplib: to safeguard the user's privacy, anonymous login will use
65 "anonymous@" as default password, rather than the real user and host
66 name.
67
Fred Drake36736122002-01-10 13:50:31 +000068- webbrowser: tightened up the command passed to os.system() so that
69 arbitrary shell code can't be executed because a bogus URL was
70 passed in.
71
Tim Peters11bd9942002-02-01 00:52:29 +000072- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000073 gettext.find an optional all argument. Translations will now fallback
74 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000075
Martin v. Löwis9668b932002-01-12 11:27:42 +000076- distutils bdist commands now offer a --skip-build option.
77
Walter Dörwaldb25c2b02002-03-21 10:38:40 +000078- warnings.warn now accepts a Warning instance as first argument.
79
Tim Petersaf8446f2001-12-21 21:36:50 +000080Tools/Demos
81
82Build
83
84C API
85
Neil Schemenauer9d50d132002-03-22 17:06:59 +000086- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
87 functions will be allocated using pymalloc if it is enabled. These
88 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
89 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
90 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
91 PyCore_* family of APIs have been removed.
92
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000093- The "u#" parser marker will now pass through Unicode object as-is
94 without going through the buffer API.
95
Martin v. Löwis7198a522002-01-01 19:59:11 +000096- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
97
Tim Peters10a3bb52001-12-25 19:07:38 +000098- An old #define of ANY as void has been removed from pyport.h. This
99 hasn't been used since Python's pre-ANSI days, and the #define has
100 been marked as obsolete since then. SF bug 495548 says it created
101 conflicts with other packages, so keeping it around wasn't harmless.
102
Tim Petersaf8446f2001-12-21 21:36:50 +0000103- Because Python's magic number scheme broke on January 1st, we decided
104 to stop Python development. Thanks for all the fish!
105
Tim Petersfb05db22002-03-11 00:24:00 +0000106- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000107 scheme to a new one. See Python/import.c for details.
108
Tim Petersaf8446f2001-12-21 21:36:50 +0000109New platforms
110
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000111- GNU/Hurd is now supported.
112
Tim Petersaf8446f2001-12-21 21:36:50 +0000113Tests
114
115Windows
116
Tim Petersfb05db22002-03-11 00:24:00 +0000117- file.truncate([newsize]) now works on Windows for all newsize values.
118 It used to fail if newsize didn't fit in 32 bits, reflecting a
119 limitation of MS _chsize (which is no longer used).
120
Tim Petersab034fa2002-02-01 11:27:43 +0000121- os.waitpid() is now implemented for Windows, and can be used to block
122 until a specified process exits. This is similar to, but not exactly
123 the same as, os.waitpid() on POSIX systems. If you're waiting for
124 a specific process whose pid was obtained from one of the spawn()
125 functions, the same Python os.waitpid() code works across platforms.
126 See the docs for details.
127
Tim Peters11bd9942002-02-01 00:52:29 +0000128- New tempfile.TemporaryFile implementation for Windows: this doesn't
129 need a TemproraryFileWrapper wrapper anymore, and should be immune
130 to a nasty problem: before 2.3, if you got a temp file on Windows, it
131 got wrapped in an object whose close() method first closed the
132 underlying file, then deleted the file. This usually worked fine.
133 However, the spawn family of functions on Windows create (at a low C
134 level) the same set of open files in the spawned process Q as were
135 open in the spawning process P. If a temp file f was among them, then
136 doing f.close() in P first closed P's C-level file handle on f, but Q's
137 C-level file handle on f remained open, so the attempt in P to delete f
138 blew up with a "Permission denied" error (Windows doesn't allow
139 deleting open files). This was surprising, subtle, and difficult to
140 work around.
141
142- The os module now exports all the symbolic constants usable with the
143 low-level os.open() on Windows: the new constants in 2.3 are
144 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
145 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
146 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
147 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
148 (so specify both if you want both; note that neither is useful unless
149 specified with O_CREAT too).
150
Tim Petersaf8446f2001-12-21 21:36:50 +0000151Mac
152
153
Tim Peters909c0912001-12-14 23:16:18 +0000154What's New in Python 2.2 final?
155Release date: 21-Dec-2001
156===============================
157
158Type/class unification and new-style classes
159
Barry Warsaw52acb492001-12-21 20:04:22 +0000160- pickle.py, cPickle: allow pickling instances of new-style classes
161 with a custom metaclass.
162
Tim Peters909c0912001-12-14 23:16:18 +0000163Core and builtins
164
Barry Warsaw52acb492001-12-21 20:04:22 +0000165- weakref proxy object: when comparing, unwrap both arguments if both
166 are proxies.
167
Tim Peters909c0912001-12-14 23:16:18 +0000168Extension modules
169
Barry Warsaw52acb492001-12-21 20:04:22 +0000170- binascii.b2a_base64(): fix a potential buffer overrun when encoding
171 very short strings.
172
173- cPickle: the obscure "fast" mode was suspected of causing stack
174 overflows on the Mac. Hopefully fixed this by setting the recursion
175 limit much smaller. If the limit is too low (it only affects
176 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
177 when compiling cPickle.c (or in pyconfig.h).
178
Tim Peters909c0912001-12-14 23:16:18 +0000179Library
180
Barry Warsaw52acb492001-12-21 20:04:22 +0000181- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
182 close or delete time).
183
184- rfc822.py: fixed a bug where the address '<>' was converted to None
185 instead of an empty string (also fixes the email.Utils module).
186
187- xmlrpclib.py: version 1.0.0; uses precision for doubles.
188
189- test suite: the pickle and cPickle tests were not executing any code
190 when run from the standard regresssion test.
191
Tim Peters909c0912001-12-14 23:16:18 +0000192Tools/Demos
193
194Build
195
196C API
197
198New platforms
199
200Tests
201
202Windows
203
Barry Warsaw52acb492001-12-21 20:04:22 +0000204- distutils package: fixed broken Windows installers (bdist_wininst).
205
206- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
207 instances are deleted at process exit time.
208
209- socket.py: prevent mysterious warnings when socket instances are
210 deleted at process exit time.
211
212- posixmodule.c: fix a Windows crash with stat() of a filename ending
213 in backslash.
214
Tim Peters909c0912001-12-14 23:16:18 +0000215Mac
216
Barry Warsaw52acb492001-12-21 20:04:22 +0000217- The Carbon toolbox modules have been upgraded to Universal Headers
218 3.4, and experimental CoreGraphics and CarbonEvents modules have
219 been added. All only for framework-enabled MacOSX.
220
Tim Peters909c0912001-12-14 23:16:18 +0000221
Tim Peters6272dfd2001-12-13 19:34:00 +0000222What's New in Python 2.2c1?
223Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000224===========================
225
226Type/class unification and new-style classes
227
Barry Warsaw06557452001-12-14 20:47:12 +0000228- Guido's tutorial introduction to the new type/class features has
229 been extensively updated. See
230
231 http://www.python.org/2.2/descrintro.html
232
233 That remains the primary documentation in this area.
234
Guido van Rossum33bab012001-12-05 22:45:48 +0000235- Fixed a leak: instance variables declared with __slots__ were never
236 deleted!
237
Guido van Rossum4b800852001-12-03 00:54:52 +0000238- The "delete attribute" method of descriptor objects is called
239 __delete__, not __del__. In previous releases, it was mistakenly
240 called __del__, which created an unfortunate overloading condition
241 with finalizers. (The "get attribute" and "set attribute" methods
242 are still called __get__ and __set__, respectively.)
243
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000244- Some subtle issues with the super built-in were fixed:
245
246 (a) When super itself is subclassed, its __get__ method would still
247 return an instance of the base class (i.e., of super).
248
249 (b) super(C, C()).__class__ would return C rather than super. This
250 is confusing. To fix this, I decided to change the semantics of
251 super so that it only applies to code attributes, not to data
252 attributes. After all, overriding data attributes is not
253 supported anyway.
254
255 (c) The __get__ method didn't check whether the argument was an
256 instance of the type used in creation of the super instance.
257
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000258- Previously, hash() of an instance of a subclass of a mutable type
259 (list or dictionary) would return some value, rather than raising
260 TypeError. This has been fixed. Also, directly calling
261 dict.__hash__ and list.__hash__ now raises the same TypeError
262 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000263
Guido van Rossumd331cb52001-12-05 19:46:42 +0000264- New-style objects now support deleting their __dict__. This is for
265 all intents and purposes equivalent to assigning a brand new empty
266 dictionary, but saves space if the object is not used further.
267
Tim Petersb3c9af12001-11-17 00:21:57 +0000268Core and builtins
269
Tim Peters3caca232001-12-06 06:23:26 +0000270- -Qnew now works as documented in PEP 238: when -Qnew is passed on
271 the command line, all occurrences of "/" use true division instead
272 of classic division. See the PEP for details. Note that "all"
273 means all instances in library and 3rd-party modules, as well as in
274 your own code. As the PEP says, -Qnew is intended for use only in
275 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000276 Note that test_coercion.py in the standard Python test suite fails
277 under -Qnew; this is expected, and won't be repaired until true
278 division becomes the default (in the meantime, test_coercion is
279 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000280
Fred Drake6c01e252001-12-14 17:08:12 +0000281- complex() now only allows the first argument to be a string
282 argument, and raises TypeError if either the second arg is a string
283 or if the second arg is specified when the first is a string.
284
Tim Petersb3c9af12001-11-17 00:21:57 +0000285Extension modules
286
Martin v. Löwis560da622001-11-24 09:24:51 +0000287- gc.get_referents was renamed to gc.get_referrers.
288
Tim Petersb3c9af12001-11-17 00:21:57 +0000289Library
290
Tim Peters25059d32001-12-07 20:35:43 +0000291- Functions in the os.spawn() family now release the global interpreter
292 lock around calling the platform spawn. They should always have done
293 this, but did not before 2.2c1. Multithreaded programs calling
294 an os.spawn function with P_WAIT will no longer block all Python threads
295 until the spawned program completes. It's possible that some programs
296 relies on blocking, although more likely by accident than by design.
297
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000298- webbrowser defaults to netscape.exe on OS/2 now.
299
Martin v. Löwis652e1912001-11-25 14:50:56 +0000300- Tix.ResizeHandle exposes detach_widget, hide, and show.
301
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000302- The charset alias windows_1252 has been added.
303
Barry Warsaw06557452001-12-14 20:47:12 +0000304- types.StringTypes is a tuple containing the defined string types;
305 usually this will be (str, unicode), but if Python was compiled
306 without Unicode support it will be just (str,).
307
308- The pulldom and minidom modules were synchronized to PyXML.
309
Tim Petersb3c9af12001-11-17 00:21:57 +0000310Tools/Demos
311
Barry Warsaw06557452001-12-14 20:47:12 +0000312- A new script called Tools/scripts/google.py was added, which fires
313 off a search on Google.
314
Tim Petersb3c9af12001-11-17 00:21:57 +0000315Build
316
Barry Warsaw06557452001-12-14 20:47:12 +0000317- Note that release builds of Python should arrange to define the
318 preprocessor symbol NDEBUG on the command line (or equivalent).
319 In the 2.2 pre-release series we tried to define this by magic in
320 Python.h instead, but it proved to cause problems for extension
321 authors. The Unix, Windows and Mac builds now all define NDEBUG in
322 release builds via cmdline (or equivalent) instead. Ports to
323 other platforms should do likewise.
324
Jack Jansen1999ef42001-12-06 21:47:20 +0000325- It is no longer necessary to use --with-suffix when building on a
326 case-insensitive file system (such as Mac OS X HFS+). In the build
327 directory an extension is used, but not in the installed python.
328
Tim Petersb3c9af12001-11-17 00:21:57 +0000329C API
330
Tim Petersf582b822001-12-11 18:51:08 +0000331- New function PyDict_MergeFromSeq2() exposes the builtin dict
332 constructor's logic for updating a dictionary from an iterable object
333 producing key-value pairs.
334
Tim Peterscffed4b2001-11-29 03:26:37 +0000335- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000336 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000337 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
338 dump core in some bad cases. This has been repaired. As a result,
339 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
340 previously went unchallenged.
341
Tim Petersb3c9af12001-11-17 00:21:57 +0000342New platforms
343
344Tests
345
346Windows
347
348Mac
349
Jack Jansenffa260f2001-12-06 21:14:00 +0000350- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
351 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000352
Barry Warsaw06557452001-12-14 20:47:12 +0000353- Changed logic for finding python home in Mac OS X framework Pythons.
354 Now sys.executable points to the executable again, in stead of to
355 the shared library. The latter is used only for locating the python
356 home.
357
358
Tim Peters84362bc2001-10-19 17:55:30 +0000359What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000360Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000361===========================
362
363Type/class unification and new-style classes
364
Guido van Rossum3d27df02001-11-15 20:27:54 +0000365- Multiple inheritance mixing new-style and classic classes in the
366 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000367
368 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000369 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000370
371 The MRO (method resolution order) for each base class is respected
372 according to its kind, but the MRO for the derived class is computed
373 using new-style MRO rules if any base clase is a new-style class.
374 This needs to be documented.
375
Tim Petersa427a2b2001-10-29 22:25:45 +0000376- The new builtin dictionary() constructor, and dictionary type, have
377 been renamed to dict. This reflects a decade of common usage.
378
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000379- dict() now accepts an iterable object producing 2-sequences. For
380 example, dict(d.items()) == d for any dictionary d. The argument,
381 and the elements of the argument, can be any iterable objects.
382
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000383- New-style classes can now have a __del__ method, which is called
384 when the instance is deleted (just like for classic classes).
385
Guido van Rossum12d955c2001-10-26 14:56:06 +0000386- Assignment to object.__dict__ is now possible, for objects that are
387 instances of new-style classes that have a __dict__ (unless the base
388 class forbids it).
389
Guido van Rossumc8e56452001-10-22 00:43:43 +0000390- Methods of built-in types now properly check for keyword arguments
391 (formerly these were silently ignored). The only built-in methods
392 that take keyword arguments are __call__, __init__ and __new__.
393
Guido van Rossum86443212001-10-27 22:28:54 +0000394- The socket function has been converted to a type; see below.
395
Tim Peters84362bc2001-10-19 17:55:30 +0000396Core and builtins
397
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000398- Assignment to __debug__ raises SyntaxError at compile-time. This
399 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000400 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000401
Guido van Rossum12d955c2001-10-26 14:56:06 +0000402- Clarified the error messages for unsupported operands to an operator
403 (like 1 + '').
404
Tim Peters84362bc2001-10-19 17:55:30 +0000405Extension modules
406
Tim Peters5ebfd362001-11-13 23:11:19 +0000407- mmap has a new keyword argument, "access", allowing a uniform way for
408 both Windows and Unix users to create read-only, write-through and
409 copy-on-write memory mappings. This was previously possible only on
410 Unix. A new keyword argument was required to support this in a
411 uniform way because the mmap() signuatures had diverged across
412 platforms. Thanks to Jay T Miller for repairing this!
413
Tim Peters169ded02001-11-03 19:57:21 +0000414- By default, the gc.garbage list now contains only those instances in
415 unreachable cycles that have __del__ methods; in 2.1 it contained all
416 instances in unreachable cycles. "Instances" here has been generalized
417 to include instances of both new-style and old-style classes.
418
Guido van Rossum12d955c2001-10-26 14:56:06 +0000419- The socket module defines a new method for socket objects,
420 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000421 send() until all data has been sent. Also, the socket function has
422 been converted to a subclassable type, like list and tuple (etc.)
423 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000424
425- Various bugfixes to the curses module. There is now a test suite
426 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000427
Guido van Rossum692adf12001-10-30 03:03:03 +0000428- binascii.b2a_base64 no longer places an arbitrary restriction of 57
429 bytes on its input.
430
Tim Peters84362bc2001-10-19 17:55:30 +0000431Library
432
Tim Peters5ebfd362001-11-13 23:11:19 +0000433- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000434 convenience function.
435
Tim Peters75335872001-11-03 19:35:43 +0000436- Symbolic group names in regular expressions must be unique. For
437 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
438 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000439 Python 2.2 detects this error at regexp compilation time;
440 previously, the error went undetected, and results were
441 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
442 pattern.subn() methods have been rewritten in C. Also, an
443 experimental function/method finditer() has been added, which works
444 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000445
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000446- Tix exposes more commands through the classes DirSelectBox,
447 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
448 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
449 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
450
Tim Peters98791af2001-10-23 01:59:54 +0000451- Traceback objects are now scanned by cyclic garbage collection, so
452 cycles created by casual use of sys.exc_info() no longer cause
453 permanent memory leaks (provided garbage collection is enabled).
454
Guido van Rossum49192142001-10-24 20:51:44 +0000455- os.extsep -- a new variable needed by the RISCOS support. It is the
456 separator used by extensions, and is '.' on all platforms except
457 RISCOS, where it is '/'. There is no need to use this variable
458 unless you have a masochistic desire to port your code to RISCOS.
459
Barry Warsaw012852b2001-11-16 16:17:27 +0000460- mimetypes.py has optional support for non-standard, but commonly
461 found types. guess_type() and guess_extension() now accept an
462 optional `strict' flag, defaulting to true, which controls whether
463 recognize non-standard types or not. A few non-standard types we
464 know about have been added. Also, when run as a script, there are
465 new -l and -e options.
466
467- statcache is now deprecated.
468
469- email.Utils.formatdate() now produces the preferred RFC 2822 style
470 dates with numeric timezones (it used to produce obsolete dates
471 hard coded to "GMT" timezone). An optional `localtime' flag is
472 added to produce dates in the local timezone, with daylight savings
473 time properly taken into account.
474
475- In pickle and cPickle, instead of masking errors in load() by
476 transforming them into SystemError, we let the original exception
477 propagate out. Also, implement support for __safe_for_unpickling__
478 in pickle, as it already was supported in cPickle.
479
Tim Peters84362bc2001-10-19 17:55:30 +0000480Tools/Demos
481
482Build
483
Barry Warsaw012852b2001-11-16 16:17:27 +0000484- The dbm module is built using libdb1 if available. The bsddb module
485 is built with libdb3 if available.
486
487- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
488
Tim Peters84362bc2001-10-19 17:55:30 +0000489C API
490
Tim Peters1fc240e2001-10-26 05:06:50 +0000491- New function PySequence_Fast_GET_SIZE() returns the size of a non-
492 NULL result from PySequence_Fast(), more quickly than calling
493 PySequence_Size().
494
Barry Warsaw012852b2001-11-16 16:17:27 +0000495- New argument unpacking function PyArg_UnpackTuple() added.
496
497- New functions PyObject_CallFunctionObjArgs() and
498 PyObject_CallMethodObjArgs() have been added to make it more
499 convenient and efficient to call functions and methods from C.
500
501- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
502 possible that this will propagate errors it didn't before.
503
504- New function PyObject_CheckReadBuffer(), which returns true if its
505 argument supports the single-segment readable buffer interface.
506
Tim Peters84362bc2001-10-19 17:55:30 +0000507New platforms
508
Guido van Rossum86443212001-10-27 22:28:54 +0000509- We've finally confirmed that this release builds on HP-UX 11.00,
510 *with* threads, and passes the test suite.
511
Tim Peters7a33d8b2001-11-05 02:51:07 +0000512- Thanks to a series of patches from Michael Muller, Python may build
513 again under OS/2 Visual Age C++.
514
Guido van Rossum49192142001-10-24 20:51:44 +0000515- Updated RISCOS port by Dietmar Schwertberger.
516
Tim Peters84362bc2001-10-19 17:55:30 +0000517Tests
518
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000519- Added a test script for the curses module. It isn't run automatically;
520 regrtest.py must be run with '-u curses' to enable it.
521
Tim Peters84362bc2001-10-19 17:55:30 +0000522Windows
523
Barry Warsaw012852b2001-11-16 16:17:27 +0000524Mac
525
526- PythonScript has been moved to unsupported and is slated to be
527 removed completely in the next release.
528
529- It should now be possible to build applets that work on both OS9 and
530 OSX.
531
532- The core is now linked with CoreServices not Carbon; as a side
533 result, default 8bit encoding on OSX is now ASCII.
534
535- Python should now build on OSX 10.1.1
536
Tim Peters84362bc2001-10-19 17:55:30 +0000537
Tim Petersabf925f2001-09-28 21:53:42 +0000538What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000539Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000540===========================
541
542Type/class unification and new-style classes
543
Guido van Rossum687ae002001-10-15 22:03:32 +0000544- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000545 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000546 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000547 remains: the __dict__ of a new-style class is a read-only proxy; you
548 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000549 __defined__ attribute of new-style types no longer exists, for lack
550 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000551 future a __cache__ may be resurrected with a similar function, if I
552 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000553
Tim Peters1c9ca872001-10-04 06:43:12 +0000554- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
555 always returned None, even when there was a class docstring).
556
557- doctest now finds and runs docstrings attached to new-style classes,
558 class methods, static methods, and properties.
559
Guido van Rossum9074ef62001-10-16 21:34:49 +0000560Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000561
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000562- A very subtle syntactical pitfall in list comprehensions was fixed.
563 For example: [a+b for a in 'abc', for b in 'def']. The comma in
564 this example is a mistake. Previously, this would silently let 'a'
565 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
566 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
567 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
568 Note that [a for a in <singleton>] is a convoluted way to say
569 [<singleton>] anyway, so it's not like any expressiveness is lost.
570
Guido van Rossum9074ef62001-10-16 21:34:49 +0000571- getattr(obj, name, default) now only catches AttributeError, as
572 documented, rather than returning the default value for all
573 exceptions (which could mask bugs in a __getattr__ hook, for
574 example).
575
Fred Drakecb7a6b52001-10-22 18:41:51 +0000576- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000577 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000578 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000579 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000580
Guido van Rossum1c486092001-10-19 02:05:35 +0000581- unicode(obj) now behaves more like str(obj), accepting arbitrary
582 objects, and calling a __unicode__ method if it exists.
583 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000584 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000585
Barry Warsawf6fb1712001-10-19 05:35:40 +0000586- isinstance() now allows any object as the first argument and a
587 class, a type or something with a __bases__ tuple attribute for the
588 second argument. The second argument may also be a tuple of a
589 class, type, or something with __bases__, in which case isinstance()
590 will return true if the first argument is an instance of any of the
591 things contained in the second argument tuple. E.g.
592
593 isinstance(x, (A, B))
594
595 returns true if x is an instance of A or B.
596
Guido van Rossum9074ef62001-10-16 21:34:49 +0000597Extension modules
598
599- thread.start_new_thread() now returns the thread ID (previously None).
600
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000601- binascii has now two quopri support functions, a2b_qp and b2a_qp.
602
Guido van Rossumc524d952001-10-19 01:31:59 +0000603- readline now supports setting the startup_hook and the
604 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000605
Guido van Rossumc524d952001-10-19 01:31:59 +0000606- os and posix supports chroot(), setgroups() and unsetenv() where
607 available. The stat(), fstat(), statvfs() and fstatvfs() functions
608 now return "pseudo-sequences" -- the various fields can now be
609 accessed as attributes (e.g. os.stat("/").st_mtime) but for
610 backwards compatibility they also behave as a fixed-length sequence.
611 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000612 attributes.
613
614- time: localtime(), gmtime() and strptime() now return a
615 pseudo-sequence similar to the os.stat() return value, with
616 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000617
Guido van Rossum9074ef62001-10-16 21:34:49 +0000618- Decompression objects in the zlib module now accept an optional
619 second parameter to decompress() that specifies the maximum amount
620 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000621
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000622- optional SSL support in the socket module now exports OpenSSL
623 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
624 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000625 automatically seed its PRNG. Also, the keyfile and certfile
626 arguments to socket.ssl() are now optional.
627
628- posixmodule (and by extension, the os module on POSIX platforms) now
629 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000630
Guido van Rossum9074ef62001-10-16 21:34:49 +0000631Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000632
Tim Peters7402f792001-10-02 03:53:41 +0000633- doctest now excludes functions and classes not defined by the module
634 being tested, thanks to Tim Hochberg.
635
Fred Drakecb7a6b52001-10-22 18:41:51 +0000636- HotShot, a new profiler implemented using a C-based callback, has
637 been added. This substantially reduces the overhead of profiling,
638 but it is still quite preliminary. Support modules and
639 documentation will be added in upcoming releases (before 2.2 final).
640
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000641- profile now produces correct output in situations where an exception
642 raised in Python is cleared by C code (e.g. hasattr()). This used
643 to cause wrong output, including spurious claims of recursive
644 functions and attribution of time spent to the wrong function.
645
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000646 The code and documentation for the derived OldProfile and HotProfile
647 profiling classes was removed. The code hasn't worked for years (if
648 you tried to use them, they raised exceptions). OldProfile
649 intended to reproduce the behavior of the profiler Python used more
650 than 7 years ago, and isn't interesting anymore. HotProfile intended
651 to provide a faster profiler (but producing less information), and
652 that's a worthy goal we intend to meet via a different approach (but
653 without losing information).
654
Tim Peterscce092d2001-10-09 05:31:56 +0000655- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000656 a much better system-specific calibration constant. The constant can
657 now be specified in an instance constructor, or as a Profile class or
658 instance variable, instead of by editing profile.py's source code.
659 Calibration must still be done manually (see the docs for the profile
660 module).
661
662 Note that Profile.calibrate() must be overriden by subclasses.
663 Improving the accuracy required exploiting detailed knowledge of
664 profiler internals; the earlier method abstracted away the details
665 and measured a simplified model instead, but consequently computed
666 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000667
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000668- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000669 which indicates whether output is intended for the header 'Q'
670 encoding.
671
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000672- The SocketServer.ThreadingMixIn class now closes the request after
673 finish_request() returns. (Not when it errors out though.)
674
Barry Warsawf6fb1712001-10-19 05:35:40 +0000675- The nntplib module's NNTP.body() method has grown a `file' argument
676 to allow saving the message body to a file.
677
678- The email package has added a class email.Parser.HeaderParser which
679 only parses headers and does not recurse into the message's body.
680 Also, the module/class MIMEAudio has been added for representing
681 audio data (contributed by Anthony Baxter).
682
683- ftplib should be able to handle files > 2GB.
684
685- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
686 ON, and OFF.
687
Fred Drakecb7a6b52001-10-22 18:41:51 +0000688- xml.dom.minidom NodeList objects now support the length attribute
689 and item() method as required by the DOM specifications.
690
Guido van Rossumed554f62001-10-02 23:15:37 +0000691Tools/Demos
692
693- Demo/dns was removed. It no longer serves any purpose; a package
694 derived from it is now maintained by Anthony Baxter, see
695 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000696
Barry Warsawf6fb1712001-10-19 05:35:40 +0000697- The freeze tool has been made more robust, and two new options have
698 been added: -X and -E.
699
Tim Petersabf925f2001-09-28 21:53:42 +0000700Build
701
Barry Warsawf6fb1712001-10-19 05:35:40 +0000702- configure will use CXX in LINKCC if CXX is used to build main() and
703 the system requires to link a C++ main using the C++ compiler.
704
Tim Petersabf925f2001-09-28 21:53:42 +0000705C API
706
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000707- The documentation for the tp_compare slot is updated to require that
708 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
709 not correct. This is not yet enforced but will be enforced in
710 Python 2.3; even later, we may use -2 to indicate errors and +2 for
711 "NotImplemented". Right now, -1 should be used for an error return.
712
Tim Petersd38b1c72001-09-30 05:09:37 +0000713- PyLong_AsLongLong() now accepts int (as well as long) arguments.
714 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
715 as long) arguments.
716
Guido van Rossum3c288632001-10-16 21:13:49 +0000717- PyThread_start_new_thread() now returns a long int giving the thread
718 ID, if one can be calculated; it returns -1 for error, 0 if no
719 thread ID is calculated (this is an incompatible change, but only
720 the thread module used this API). This code has only really been
721 tested on Linux and Windows; other platforms please beware (and
722 report any bugs or strange behavior).
723
Guido van Rossum1c486092001-10-19 02:05:35 +0000724- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
725 input.
726
Tim Petersabf925f2001-09-28 21:53:42 +0000727New platforms
728
729Tests
730
731Windows
732
Tim Peters04cf1d32001-10-09 22:39:40 +0000733- Installer: If you install IDLE, and don't disable file-extension
734 registration, a new "Edit with IDLE" context (right-click) menu entry
735 is created for .py and .pyw files.
736
Tim Peters1ce3cf72001-10-01 17:58:40 +0000737- The signal module now supports SIGBREAK on Windows, thanks to Steven
738 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
739 action remains to call Win32 ExitProcess(). This can be changed via
740 signal.signal(). For example:
741
742 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
743 # (SIGINT) behavior.
744 import signal
745 signal.signal(signal.SIGBREAK,
746 signal.default_int_handler)
747
748 try:
749 while 1:
750 pass
751 except KeyboardInterrupt:
752 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
753 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
754 # program without the possibility for any Python-level cleanup).
755 print "Clean exit"
756
Tim Petersabf925f2001-09-28 21:53:42 +0000757
Tim Petersb07352e2001-09-08 01:25:47 +0000758What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000759Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000760===========================
761
Guido van Rossum808eea72001-09-25 04:15:41 +0000762Type/class unification and new-style classes
763
764- pydoc and inspect are now aware of new-style classes;
765 e.g. help(list) at the interactive prompt now shows proper
766 documentation for all operations on list objects.
767
768- Applications using Jim Fulton's ExtensionClass module can now safely
769 be used with Python 2.2. In particular, Zope 2.4.1 now works with
770 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
771 examples also work again. It is hoped that Gtk and Boost also work
772 with 2.2a4 and beyond. (If you can confirm this, please write
773 webmaster@python.org; if there are still problems, please open a bug
774 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000775
Tim Peters66c1a522001-09-24 21:17:50 +0000776- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
777 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
778 in the constructed property object. fget, fset and fdel weren't
779 discoverable from Python in 2.2a3. __doc__ is new, and allows to
780 associate a docstring with a property.
781
Guido van Rossum808eea72001-09-25 04:15:41 +0000782- Comparison overloading is now more completely implemented. For
783 example, a str subclass instance can properly be compared to a str
784 instance, and it can properly overload comparison. Ditto for most
785 other built-in object types.
786
787- The repr() of new-style classes has changed; instead of <type
788 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
789 *except* for built-in types, which are still rendered as <type
790 'Foo'> (to avoid upsetting existing code that might parse or
791 otherwise rely on repr() of certain type objects).
792
793- The repr() of new-style objects is now always <Foo object at XXX>;
794 previously, it was sometimes <Foo instance at XXX>.
795
796- For new-style classes, what was previously called __getattr__ is now
797 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000798 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000799 one in classic classes is defined which is called only if regular
800 attribute access raises AttributeError; to catch *all* attribute
801 access, you can use __getattribute__ (for new-style classes). If
802 both are defined, __getattribute__ is called first, and if it raises
803 AttributeError, __getattr__ is called.
804
805- The __class__ attribute of new-style objects can be assigned to.
806 The new class must have the same C-level object layout as the old
807 class.
808
809- The builtin file type can be subclassed now. In the usual pattern,
810 "file" is the name of the builtin type, and file() is a new builtin
811 constructor, with the same signature as the builtin open() function.
812 file() is now the preferred way to open a file.
813
814- Previously, __new__ would only see sequential arguments passed to
815 the type in a constructor call; __init__ would see both sequential
816 and keyword arguments. This made no sense whatsoever any more, so
817 now both __new__ and __init__ see all arguments.
818
819- Previously, hash() applied to an instance of a subclass of str or
820 unicode always returned 0. This has been repaired.
821
822- Previously, an operation on an instance of a subclass of an
823 immutable type (int, long, float, complex, tuple, str, unicode),
824 where the subtype didn't override the operation (and so the
825 operation was handled by the builtin type), could return that
826 instance instead a value of the base type. For example, if s was of
827 a str sublass type, s[:] returned s as-is. Now it returns a str
828 with the same value as s.
829
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000830- Provisional support for pickling new-style objects has been added.
831
Guido van Rossum808eea72001-09-25 04:15:41 +0000832Core
833
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000834- file.writelines() now accepts any iterable object producing strings.
835
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000836- PyUnicode_FromEncodedObject() now works very much like
837 PyObject_Str(obj) in that it tries to use __str__/tp_str
838 on the object if the object is not a string or buffer. This
839 makes unicode() behave like str() when applied to non-string/buffer
840 objects.
841
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000842- PyFile_WriteObject now passes Unicode objects to the file's write
843 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000844 of a print statement must support Unicode objects, i.e. they must
845 at least convert them into ASCII strings.
846
Guido van Rossum624c8af2001-09-18 15:21:04 +0000847- Thread scheduling on Solaris should be improved; it is no longer
848 necessary to insert a small sleep at the start of a thread in order
849 to let other runnable threads be scheduled.
850
Tim Petersb07352e2001-09-08 01:25:47 +0000851Library
852
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000853- StringIO.StringIO instances and cStringIO.StringIO instances support
854 read character buffer compatible objects for their .write() methods.
855 These objects are converted to strings and then handled as such
856 by the instances.
857
Barry Warsaw2f600732001-09-24 04:28:10 +0000858- The "email" package has been added. This is basically a port of the
859 mimelib package <http://sf.net/projects/mimelib> with API changes
860 and some implementations updated to use iterators and generators.
861
Tim Peters8a9c2842001-09-22 21:30:22 +0000862- difflib.ndiff() and difflib.Differ.compare() are generators now. This
863 restores the ability of Tools/scripts/ndiff.py to start producing output
864 before the entire comparison is complete.
865
Barry Warsaw58b072d2001-09-22 04:44:21 +0000866- StringIO.StringIO instances and cStringIO.StringIO instances support
867 iteration just like file objects (i.e. their .readline() method is
868 called for each iteration until it returns an empty string).
869
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000870- The codecs module has grown four new helper APIs to access
871 builtin codecs: getencoder(), getdecoder(), getreader(),
872 getwriter().
873
Guido van Rossum624c8af2001-09-18 15:21:04 +0000874- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
875 simplifies writing XML RPC servers.
876
Barry Warsaw647d5e82001-09-28 17:01:02 +0000877- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000878 after interpretation of symbolic links. On non-Unix systems, this
879 is an alias for os.path.abspath().
880
Tim Peters16a77ad2001-09-08 04:00:12 +0000881- operator.indexOf() (PySequence_Index() in the C API) now works with any
882 iterable object.
883
Guido van Rossum624c8af2001-09-18 15:21:04 +0000884- smtplib now supports various authentication and security features of
885 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000886
Guido van Rossum624c8af2001-09-18 15:21:04 +0000887- hmac: a new module implementing keyed hashing for message
888 authentication.
889
890- mimetypes now recognizes more extensions and file types. At the
891 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000892
Guido van Rossum624c8af2001-09-18 15:21:04 +0000893- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000894 Python 2.2 bytecode generation. It has also been promoted from a
895 Tool to a standard library package. (Tools/compiler still exists as
896 a sample driver.)
897
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000898Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000899
Tim Petersb07352e2001-09-08 01:25:47 +0000900Build
901
Guido van Rossum624c8af2001-09-18 15:21:04 +0000902- Large file support (LFS) is now automatic when the platform supports
903 it; no more manual configuration tweaks are needed. On Linux, at
904 least, it's possible to have a system whose C library supports large
905 files but whose kernel doesn't; in this case, large file support is
906 still enabled but doesn't do you any good unless you upgrade your
907 kernel or share your Python executable with another system whose
908 kernel has large file support.
909
910- The configure script now supplies plausible defaults in a
911 cross-compilation environment. This doesn't mean that the supplied
912 values are always correct, or that cross-compilation now works
913 flawlessly -- but it's a first step (and it shuts up most of
914 autoconf's warnings about AC_TRY_RUN).
915
916- The Unix build is now a bit less chatty, courtesy of the parser
917 generator. The build is completely silent (except for errors) when
918 using "make -s", thanks to a -q option to setup.py.
919
Tim Petersb07352e2001-09-08 01:25:47 +0000920C API
921
Guido van Rossum624c8af2001-09-18 15:21:04 +0000922- The "structmember" API now supports some new flag bits to deny read
923 and/or write access to attributes in restricted execution mode.
924
Tim Petersb07352e2001-09-08 01:25:47 +0000925New platforms
926
Guido van Rossum624c8af2001-09-18 15:21:04 +0000927- Compaq's iPAQ handheld, running the "familiar" Linux distribution
928 (http://familiar.handhelds.org).
929
Tim Petersb07352e2001-09-08 01:25:47 +0000930Tests
931
Tim Peters8a9c2842001-09-22 21:30:22 +0000932- The "classic" standard tests, which work by comparing stdout to
933 an expected-output file under Lib/test/output/, no longer stop at
934 the first mismatch. Instead the test is run to completion, and a
935 variant of ndiff-style comparison is used to report all differences.
936 This is much easier to understand than the previous style of reporting.
937
938- The unittest-based standard tests now use regrtest's test_main()
939 convention, instead of running as a side-effect of merely being
940 imported. This allows these tests to be run in more natural and
941 flexible ways as unittests, outside the regrtest framework.
942
943- regrtest.py is much better integrated with unittest and doctest now,
944 especially in regard to reporting errors.
945
Tim Petersb07352e2001-09-08 01:25:47 +0000946Windows
947
Guido van Rossum624c8af2001-09-18 15:21:04 +0000948- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000949 that support it (NTFS under Windows 2000). See "What's New in
950 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000951
Tim Petersb07352e2001-09-08 01:25:47 +0000952
Tim Petersedc99312001-08-22 21:36:50 +0000953What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000954Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000955===========================
956
957Core
958
Tim Peters9fffa3e2001-09-04 05:14:19 +0000959- Conversion of long to float now raises OverflowError if the long is too
960 big to represent as a C double.
961
Tim Peters32f453e2001-09-03 08:35:41 +0000962- The 3-argument builtin pow() no longer allows a third non-None argument
963 if either of the first two arguments is a float, or if both are of
964 integer types and the second argument is negative (in which latter case
965 the arguments are converted to float, so this is really the same
966 restriction).
967
Tim Peters5d2b77c2001-09-03 05:47:38 +0000968- The builtin dir() now returns more information, and sometimes much
969 more, generally naming all attributes of an object, and all attributes
970 reachable from the object via its class, and from its class's base
971 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
972 an empty list. In 2.2a3,
973
974 >>> dir([])
975 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
976 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
977 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
978 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
979 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
980 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
981 'reverse', 'sort']
982
983 dir(module) continues to return only the module's attributes, though.
984
Tim Petersbdee63f2001-09-02 03:40:59 +0000985- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000986 than raising OverflowError. This is a partial implementation of PEP
987 237. You can use -Wdefault::OverflowWarning to enable a warning for
988 this situation, and -Werror::OverflowWarning to revert to the old
989 OverflowError exception.
990
Guido van Rossum61c345f2001-09-04 03:26:15 +0000991- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000992 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000993 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
994 -Qold, meaning the / operator has its classic meaning and no
995 warnings are issued. Using -Qwarn issues a run-time warning about
996 all uses of classic division for int and long arguments; -Qwarnall
997 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000998 (for use with fixdiv.py).
999 [Note: the remainder of this paragraph (preserved below) became
1000 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1001 <obsolete>
1002 Using -Qnew is questionable; it turns on new division by default, but
1003 only in the __main__ module. You can usefully combine -Qwarn or
1004 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1005 warns about classic division everywhere else.
1006 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001007
Tim Petersbdee63f2001-09-02 03:40:59 +00001008- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001009 long, float, str, unicode, and tuple. (The types complex, list and
1010 dictionary can also be subclassed; this was introduced earlier.)
1011 Note that restrictions apply when subclassing immutable built-in
1012 types: you can only affect the value of the instance by overloading
1013 __new__. You can add mutable attributes, and the subclass instances
1014 will have a __dict__ attribute, but you cannot change the "value"
1015 (as implemented by the base class) of an immutable subclass instance
1016 once it is created.
1017
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001018- The dictionary constructor now takes an optional argument, a
1019 mapping-like object, and initializes the dictionary from its
1020 (key, value) pairs.
1021
Tim Petersbdee63f2001-09-02 03:40:59 +00001022- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001023 "cooperative super calls" in a multiple inheritance setting. For an
1024 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1025
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001026- A new built-in type, property, has been added. This enables the
1027 creation of "properties". These are attributes implemented by
1028 getter and setter functions (or only one of these for read-only or
1029 write-only attributes), without the need to override __getattr__.
1030 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001031
Tim Petersbdee63f2001-09-02 03:40:59 +00001032- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001033 liberalized, to allow leading zeroes. Examples of literals now
1034 legal that were SyntaxErrors before:
1035
1036 00.0 0e3 0100j 07.5 00000000000000000008.
1037
Tim Petersbdee63f2001-09-02 03:40:59 +00001038- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001039 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1040
Tim Petersedc99312001-08-22 21:36:50 +00001041Library
1042
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001043- telnetlib includes symbolic names for the options, and support for
1044 setting an option negotiation callback.
1045
Tim Petersa40c7932001-09-05 22:36:56 +00001046- The new C standard no longer requires that math libraries set errno to
1047 ERANGE on overflow. For platform libraries that exploit this new
1048 freedom, Python's overflow-checking was wholly broken. A new overflow-
1049 checking scheme attempts to repair that, but may not be reliable on all
1050 platforms (C doesn't seem to provide anything both useful and portable
1051 in this area anymore).
1052
Martin v. Löwis44f86962001-09-05 13:44:54 +00001053- Asynchronous timeout actions are available through the new class
1054 threading.Timer.
1055
Tim Peters78526162001-09-05 00:53:45 +00001056- math.log and math.log10 now return sensible results for even huge
1057 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1058
Tim Petersbdee63f2001-09-02 03:40:59 +00001059- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001060 currently held. See the docs for the imp module.
1061
Tim Petersbdee63f2001-09-02 03:40:59 +00001062- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001063 dumps containing ints written on platforms where Python ints are 8 bytes.
1064 When read on a box where Python ints are 4 bytes, such values are
1065 converted to Python longs.
1066
Tim Petersbdee63f2001-09-02 03:40:59 +00001067- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001068 code objects is no longer allowed. This plugs a security hole.
1069
Steve Purcell6091cd62001-09-06 16:05:17 +00001070- unittest.TestResult instances no longer store references to tracebacks
1071 generated by test failures. This prevents unexpected dangling references
1072 to objects that should be garbage collected between tests.
1073
Tim Petersedc99312001-08-22 21:36:50 +00001074Tools
1075
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001076- Tools/scripts/fixdiv.py has been added which can be used to fix
1077 division operators as per PEP 238.
1078
Tim Petersedc99312001-08-22 21:36:50 +00001079Build
1080
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001081- If you are an adventurous person using Mac OS X you may want to look at
1082 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1083 application, which can be used for experimenting with Carbon or Cocoa.
1084 Discussion of this on pythonmac-sig, please.
1085
Tim Peters7eea37e2001-09-04 22:08:56 +00001086C API
1087
1088- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001089
Tim Peters9fffa3e2001-09-04 05:14:19 +00001090- Note that PyLong_AsDouble can fail! This has always been true, but no
1091 callers checked for it. It's more likely to fail now, because overflow
1092 errors are properly detected now. The proper way to check:
1093
1094 double x = PyLong_AsDouble(some_long_object);
1095 if (x == -1.0 && PyErr_Occurred()) {
1096 /* The conversion failed. */
1097 }
1098
Tim Petersbdee63f2001-09-02 03:40:59 +00001099- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001100 compile but will not participate in GC. To upgrade an extension
1101 module:
1102
1103 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001104
Neil Schemenauer4042c692001-08-30 15:38:01 +00001105 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1106 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001107
Neil Schemenauer4042c692001-08-30 15:38:01 +00001108 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1109 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001110
Neil Schemenauer4042c692001-08-30 15:38:01 +00001111 - remove PyGC_HEAD_SIZE from object size calculations
1112
1113 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1114
Tim Petersbdee63f2001-09-02 03:40:59 +00001115- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001116 These can be used safely to construct string objects from a
1117 sprintf-style format string (similar to the format string supported
1118 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001119
Tim Petersedc99312001-08-22 21:36:50 +00001120New platforms
1121
Tim Petersb7da0902001-09-02 23:01:43 +00001122- Stephen Hansen contributed patches sufficient to get a clean compile
1123 under Borland C (Windows), but he reports problems running it and ran
1124 out of time to complete the port. Volunteers? Expect a MemoryError
1125 when importing the types module; this is probably shallow, and
1126 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001127
Tim Petersedc99312001-08-22 21:36:50 +00001128Tests
1129
1130Windows
1131
Tim Peters6e13a562001-09-06 00:32:15 +00001132- Large file support is now enabled on Win32 platforms as well as on
1133 Win64. This means that, for example, you can use f.tell() and f.seek()
1134 to manipulate files larger than 2 gigabytes (provided you have enough
1135 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001136 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1137 filesize limit, and large file support makes no difference there.
1138 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1139 NTFS has no practical limit on file size, and files of any size can be
1140 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001141
Tim Petersbdee63f2001-09-02 03:40:59 +00001142- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001143 points to command.com (patch from Brian Quinlan).
1144
Tim Petersedc99312001-08-22 21:36:50 +00001145
Tim Peters20f51a72001-07-21 02:31:40 +00001146What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001147Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001148===========================
1149
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001150Build
1151
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001152- Tim Peters developed a brand new Windows installer using Wise 8.1,
1153 generously donated to us by Wise Solutions.
1154
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001155- configure supports a new option --enable-unicode, with the values
1156 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1157 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001158
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001159- A new configure option --enable-framework builds a Mac OS X framework,
1160 which "make frameworkinstall" will install. This provides a starting
1161 point for more mac-like functionality, join pythonmac-sig@python.org
1162 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001163
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001164- The NeXT platform is no longer supported.
1165
1166- The `new' module is now statically linked.
1167
Tim Peters0afb6092001-08-15 06:06:44 +00001168Tools
1169
1170- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001171 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001172 the module docstring for details.
1173
Tim Peters20f51a72001-07-21 02:31:40 +00001174Tests
1175
Tim Peters5e824c32001-08-12 22:25:01 +00001176- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001177 platforms, allowing to give clearer test result output. regrtest
1178 also has optional --use/-u switch to run normally disabled tests
1179 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001180
Tim Peters20f51a72001-07-21 02:31:40 +00001181- Several new tests in the standard test suite, with special thanks to
1182 Nick Mathewson.
1183
1184Core
1185
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001186- The floor division operator // has been added as outlined in PEP
1187 238. The / operator still provides classic division (and will until
1188 Python 3.0) unless "from __future__ import division" is included, in
1189 which case the / operator will provide true division. The operator
1190 module provides truediv() and floordiv() functions. Augmented
1191 assignment variants are included, as are the equivalent overloadable
1192 methods and C API methods. See the PEP for a full discussion:
1193 <http://python.sf.net/peps/pep-0238.html>
1194
Tim Peters6cd6a822001-08-17 22:11:27 +00001195- Future statements are now effective in simulated interactive shells
1196 (like IDLE). This should "just work" by magic, but read Michael
1197 Hudson's "Future statements in simulated shells" PEP 264 for full
1198 details: <http://python.sf.net/peps/pep-0264.html>.
1199
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001200- The type/class unification (PEP 252-253) was integrated into the
1201 trunk and is not so tentative any more (the exact specification of
1202 some features is still tentative). A lot of work has done on fixing
1203 bugs and adding robustness and features (performance still has to
1204 come a long way).
1205
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001206- Warnings about a mismatch in the Python API during extension import
1207 now use the Python warning framework (which makes it possible to
1208 write filters for these warnings).
1209
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001210- A function's __dict__ (aka func_dict) will now always be a
1211 dictionary. It used to be possible to delete it or set it to None,
1212 but now both actions raise TypeErrors. It is still legal to set it
1213 to a dictionary object. Getting func.__dict__ before any attributes
1214 have been assigned now returns an empty dictionary instead of None.
1215
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001216- A new command line option, -E, was added which disables the use of
1217 all environment variables, or at least those that are specifically
1218 significant to Python. Usually those have a name starting with
1219 "PYTHON". This was used to fix a problem where the tests fail if
1220 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1221 older distribution.
1222
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001223Library
1224
Tim Peters5e824c32001-08-12 22:25:01 +00001225- New class Differ and new functions ndiff() and restore() in difflib.py.
1226 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001227 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001228
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001229- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1230 value using the minimal quoting required for the value; more
1231 reliable than using xml.sax.saxutils.escape() for attribute values.
1232
1233- Readline completion support for cmd.Cmd was added.
1234
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001235- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1236
1237- Added function threading.BoundedSemaphore()
1238
1239- Added Ka-Ping Yee's cgitb.py module.
1240
1241- The `new' module now exposes the CO_xxx flags.
1242
Martin v. Löwis560da622001-11-24 09:24:51 +00001243- The gc module offers the get_referents function.
1244
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001245New platforms
1246
1247C API
1248
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001249- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1250 which provide a cross-platform implementations for the
1251 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1252 the standard sprintf() and vsprintf() C lib APIs, these versions
1253 apply bounds checking on the used buffer which enhances protection
1254 against buffer overruns.
1255
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001256- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001257 and extensions using different Unicode widths is rendered next to
1258 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001259 will result in an ImportError. Unicode extensions writers must make
1260 sure to check the Unicode width compatibility in their extensions by
1261 using at least one of the mangled Unicode APIs in the extension.
1262
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001263- Two new flags METH_NOARGS and METH_O are available in method definition
1264 tables to simplify implementation of methods with no arguments and a
1265 single untyped argument. Calling such methods is more efficient than
1266 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1267 deprecated.
1268
Tim Petersc1731372001-08-04 08:12:36 +00001269Windows
1270
1271- "import module" now compiles module.pyw if it exists and nothing else
1272 relevant is found.
1273
Tim Peters20f51a72001-07-21 02:31:40 +00001274
Guido van Rossum55a78992001-07-17 17:22:32 +00001275What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001276Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001277===========================
1278
1279Core
Tim Petersa814db52001-05-14 07:05:58 +00001280
Tim Peters6d6c1a32001-08-02 04:15:00 +00001281- TENTATIVELY, a large amount of code implementing much of what's
1282 described in PEP 252 (Making Types Look More Like Classes) and PEP
1283 253 (Subtyping Built-in Types) was added. This will be released
1284 with Python 2.2a1. Documentation will be provided separately
1285 through http://www.python.org/2.2/. The purpose of releasing this
1286 with Python 2.2a1 is to test backwards compatibility. It is
1287 possible, though not likely, that a decision is made not to release
1288 this code as part of 2.2 final, if any serious backwards
1289 incompapatibilities are found during alpha testing that cannot be
1290 repaired.
1291
Guido van Rossum55a78992001-07-17 17:22:32 +00001292- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001293 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001294 more 'yield' statements. See PEP 255. Since this adds a new
1295 keyword to the language, this feature must be enabled by including a
1296 future statement: "from __future__ import generators" (see PEP 236).
1297 Generators will become a standard feature in a future release
1298 (probably 2.3). Without this future statement, 'yield' remains an
1299 ordinary identifier, but a warning is issued each time it is used.
1300 (These warnings currently don't conform to the warnings framework of
1301 PEP 230; we intend to fix this in 2.2a2.)
1302
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001303- The UTF-16 codec was modified to be more RFC compliant. It will now
1304 only remove BOM characters at the start of the string and then
1305 only if running in native mode (UTF-16-LE and -BE won't remove a
1306 leading BMO character).
1307
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001308- Strings now have a new method .decode() to complement the already
1309 existing .encode() method. These two methods provide direct access
1310 to the corresponding decoders and encoders of the registered codecs.
1311
1312 To enhance the usability of the .encode() method, the special
1313 casing of Unicode object return values was dropped (Unicode objects
1314 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001315
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001316 Both methods will now return whatever the codec in charge of the
1317 requested encoding returns as object, e.g. Unicode codecs will
1318 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1319 will return u"äöü"). This enables codec writer to create codecs
1320 for various simple to use conversions.
1321
1322 New codecs were added to demonstrate these new features (the .encode()
1323 and .decode() columns indicate the type of the returned objects):
1324
1325 Name | .encode() | .decode() | Description
1326 ----------------------------------------------------------------------
1327 uu | string | string | UU codec (e.g. for email)
1328 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001329 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001330 zlib | string | string | zlib compression
1331 hex | string | string | 2-byte hex codec
1332 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1333
Mark Hammond2a0af792001-05-14 03:09:36 +00001334- Some operating systems now support the concept of a default Unicode
1335 encoding for file system operations. Notably, Windows supports 'mbcs'
1336 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001337 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001338 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001339
1340 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001341 functions that return filenames (such as os.listdir()) to return Python
1342 string objects pre-encoded using the default file system encoding for
1343 the platform. As this encoding is likely to be different from Python's
1344 default encoding, converting this name to a Unicode object before passing
1345 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001346 would attempt to use its default encoding (generally ASCII) rather than
1347 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001348
Tim Petersa814db52001-05-14 07:05:58 +00001349 In general, this change simply removes surprises when working with
1350 Unicode and the file system, making these operations work as you expect,
1351 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001352 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001353
Tim Peters61dff2b2001-05-08 15:43:37 +00001354- Float (and complex) literals in source code were evaluated to full
1355 precision only when running from a .py file; the same code loaded from a
1356 .pyc (or .pyo) file could suffer numeric differences starting at about the
1357 12th significant decimal digit. For example, on a machine with IEEE-754
1358 floating arithmetic,
1359
1360 x = 9007199254740992.0
1361 print long(x)
1362
1363 printed 9007199254740992 if run directly from .py, but 9007199254740000
1364 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1365 str(float) instead of repr(float) when building code objects. marshal
1366 now uses repr(float) instead, which should reproduce floats to full
1367 machine precision (assuming the platform C float<->string I/O conversion
1368 functions are of good quality).
1369
1370 This may cause floating-point results to change in some cases, and
1371 usually for the better, but may also cause numerically unstable
1372 algorithms to break.
1373
Tim Peters2f228e72001-05-13 00:19:31 +00001374- The implementation of dicts suffers fewer collisions, which has speed
1375 benefits. However, the order in which dict entries appear in dict.keys(),
1376 dict.values() and dict.items() may differ from previous releases for a
1377 given dict. Nothing is defined about this order, so no program should
1378 rely on it. Nevertheless, it's easy to write test cases that rely on the
1379 order by accident, typically because of printing the str() or repr() of a
1380 dict to an "expected results" file. See Lib/test/test_support.py's new
1381 sortdict(dict) function for a simple way to display a dict in sorted
1382 order.
1383
Tim Peters7a3bfc32001-06-12 01:22:22 +00001384- Many other small changes to dicts were made, resulting in faster
1385 operation along the most common code paths.
1386
Guido van Rossum10315822001-05-01 20:54:30 +00001387- Dictionary objects now support the "in" operator: "x in dict" means
1388 the same as dict.has_key(x).
1389
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001390- The update() method of dictionaries now accepts generic mapping
1391 objects. Specifically the argument object must support the .keys()
1392 and __getitem__() methods. This allows you to say, for example,
1393 {}.update(UserDict())
1394
Guido van Rossum10315822001-05-01 20:54:30 +00001395- Iterators were added; this is a generalized way of providing values
1396 to a for loop. See PEP 234. There's a new built-in function iter()
1397 to return an iterator. There's a new protocol to get the next value
1398 from an iterator using the next() method (in Python) or the
1399 tp_iternext slot (in C). There's a new protocol to get iterators
1400 using the __iter__() method (in Python) or the tp_iter slot (in C).
1401 Iterating (i.e. a for loop) over a dictionary generates its keys.
1402 Iterating over a file generates its lines.
1403
Tim Petersf553f892001-05-01 20:45:31 +00001404- The following functions were generalized to work nicely with iterator
1405 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001406 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001407 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1408 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001409 join() method of strings
1410 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001411 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1412 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001413 right-hand side of assignment statements with multiple targets, such as
1414 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001415
Tim Petersd85e1022001-05-11 21:51:48 +00001416- Accessing module attributes is significantly faster (for example,
1417 random.random or os.path or yourPythonModule.yourAttribute).
1418
Tim Peterse63415e2001-05-08 04:38:29 +00001419- Comparing dictionary objects via == and != is faster, and now works even
1420 if the keys and values don't support comparisons other than ==.
1421
Tim Peters95bf9392001-05-10 08:32:44 +00001422- Comparing dictionaries in ways other than == and != is slower: there were
1423 insecurities in the dict comparison implementation that could cause Python
1424 to crash if the element comparison routines for the dict keys and/or
1425 values mutated the dicts. Making the code bulletproof slowed it down.
1426
Tim Peterseb28ef22001-06-02 05:27:19 +00001427- Collisions in dicts are resolved via a new approach, which can help
1428 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001429 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001430 faster now. Thanks to Christian Tismer for pointing out the cause and
1431 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001432
Tim Peters52e155e2001-06-16 05:42:57 +00001433- repr() is much faster for large containers (dict, list, tuple).
1434
1435
Tim Petersa814db52001-05-14 07:05:58 +00001436Library
1437
Fred Drake960fdf92001-07-20 18:38:26 +00001438- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1439 were added to the string module. These a locale-indenpendent
1440 constants, unlike letters, lowercase, and uppercase. These are now
1441 use in appropriate locations in the standard library.
1442
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001443- The flags used in dlopen calls can now be configured using
1444 sys.setdlopenflags and queried using sys.getdlopenflags.
1445
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001446- Fredrik Lundh's xmlrpclib is now a standard library module. This
1447 provides full client-side XML-RPC support. In addition,
1448 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1449 one asyncore-based). Thanks to Eric Raymond for the documentation.
1450
Guido van Rossum643d3912001-07-05 14:46:25 +00001451- The xrange() object is simplified: it no longer supports slicing,
1452 repetition, comparisons, efficient 'in' checking, the tolist()
1453 method, or the start, stop and step attributes. See PEP 260.
1454
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001455- A new function fnmatch.filter to filter lists of file names was added.
1456
Barry Warsawffd674d2001-05-22 16:00:10 +00001457- calendar.py uses month and day names based on the current locale.
1458
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001459- strop is now *really* obsolete (this was announced before with 1.6),
1460 and issues DeprecationWarning when used (except for the four items
1461 that are still imported into string.py).
1462
Tim Petersa814db52001-05-14 07:05:58 +00001463- Cookie.py now sorts key+value pairs by key in output strings.
1464
1465- pprint.isrecursive(object) didn't correctly identify recursive objects.
1466 Now it does.
1467
Tim Peters95b3f782001-05-14 18:39:41 +00001468- pprint functions now much faster for large containers (tuple, list, dict).
1469
Tim Peters7b9542a2001-06-10 23:40:19 +00001470- New 'q' and 'Q' format codes in the struct module, corresponding to C
1471 types "long long" and "unsigned long long" (on Windows, __int64). In
1472 native mode, these can be used only when the platform C compiler supports
1473 these types (when HAVE_LONG_LONG is #define'd by the Python config
1474 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001475 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1476 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001477
Guido van Rossum83213cc2001-06-12 16:48:52 +00001478- The site module installs a new built-in function 'help' that invokes
1479 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1480 it displays a message reminding the user to use 'help()' or
1481 'help(object)'.
1482
Tim Petersa814db52001-05-14 07:05:58 +00001483Tests
1484
1485- New test_mutants.py runs dict comparisons where the key and value
1486 comparison operators mutute the dicts randomly during comparison. This
1487 rapidly causes Python to crash under earlier releases (not for the faint
1488 of heart: it can also cause Win9x to freeze or reboot!).
1489
1490- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001491 pprint.isreadable() return sensible results. Also verifies that simple
1492 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001493
Tim Peters4324aa32001-05-28 22:30:08 +00001494C API
1495
1496- Removed the unused last_is_sticky argument from the internal
1497 _PyTuple_Resize(). If this affects you, you were cheating.
1498
1499
Guido van Rossum55a78992001-07-17 17:22:32 +00001500======================================================================
1501
1502
Guido van Rossumffe13be2001-04-16 18:46:45 +00001503What's New in Python 2.1 (final)?
1504=================================
1505
1506We only changed a few things since the last release candidate, all in
1507Python library code:
1508
1509- A bug in the locale module was fixed that affected locales which
1510 define no grouping for numeric formatting.
1511
1512- A few bugs in the weakref module's implementations of weak
1513 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1514 and the test suite was updated to check for these bugs.
1515
1516- An old bug in the os.path.walk() function (introduced in Python
1517 2.0!) was fixed: a non-existent file would cause an exception
1518 instead of being ignored.
1519
1520- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1521 PyChecker.
1522
1523
Guido van Rossum5b08f132001-04-16 02:05:23 +00001524What's New in Python 2.1c2?
1525===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001526
Guido van Rossum5b08f132001-04-16 02:05:23 +00001527A flurry of small changes, and one showstopper fixed in the nick of
1528time made it necessary to release another release candidate. The list
1529here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001530
Guido van Rossum5b08f132001-04-16 02:05:23 +00001531Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001532
Guido van Rossum5b08f132001-04-16 02:05:23 +00001533- Tim discovered a nasty bug in the dictionary code, caused by
1534 PyDict_Next() calling dict_resize(), and the GC code's use of
1535 PyDict_Next() violating an assumption in dict_items(). This was
1536 fixed with considerable amounts of band-aid, but the net effect is a
1537 saner and more robust implementation.
1538
1539- Made a bunch of symbols static that were accidentally global.
1540
1541Build and Ports
1542
1543- The setup.py script didn't check for a new enough version of zlib
1544 (1.1.3 is needed). Now it does.
1545
1546- Changed "make clean" target to also remove shared libraries.
1547
1548- Added a more general warning about the SGI Irix optimizer to README.
1549
1550Library
1551
1552- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1553 omitted the slash between host and file.html.
1554
1555- The mailbox module's _Mailbox class contained a completely broken
1556 and undocumented seek() method. Ripped it out.
1557
1558- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1559 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1560
1561- Fixed a few last-minute bugs in unittest.
1562
1563Extensions
1564
1565- Reverted the patch to the OpenSSL code in socketmodule.c to support
1566 RAND_status() and the EGD, and the subsequent patch that tried to
1567 fix it for pre-0.9.5 versions; the problem with the patch is that on
1568 some systems it issues a warning whenever socket is imported, and
1569 that's unacceptable.
1570
1571Tests
1572
1573- Fixed the pickle tests to work with "import test.test_pickle".
1574
1575- Tweaked test_locale.py to actually run the test Windows.
1576
1577- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1578 not "wb" (which is not a valid mode at all).
1579
1580- Fix pstats browser crashes. Import readline if it exists to make
1581 the user interface nicer.
1582
1583- Add "import thread" to the top of test modules that import the
1584 threading module (test_asynchat and test_threadedtempfile). This
1585 prevents test failures caused by a broken threading module resulting
1586 from a previously caught failed import.
1587
1588- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1589 needed on some platforms (e.g. Solaris 8) when the tests are run
1590 twice in succession.
1591
1592- Skip rather than fail test_sunaudiodev if no audio device is found.
1593
1594
1595What's New in Python 2.1c1?
1596===========================
1597
1598This list was significantly updated when 2.1c2 was released; the 2.1c1
1599release didn't mention most changes that were actually part of 2.1c1:
1600
1601Legal
1602
1603- Copyright was assigned to the Python Software Foundation (PSF) and a
1604 PSF license (very similar to the CNRI license) was added.
1605
1606- The CNRI copyright notice was updated to include 2001.
1607
1608Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001609
Guido van Rossumc9932722001-04-12 02:31:27 +00001610- After a public outcry, assignment to __debug__ is no longer illegal;
1611 instead, a warning is issued. It will become illegal in 2.2.
1612
Guido van Rossum5b08f132001-04-16 02:05:23 +00001613- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1614 "%#x" now always prepends "0x", even if the value is zero.
1615
1616- Fixed some nits in the bytecode compiler.
1617
1618- Fixed core dumps when calling certain kinds of non-functions.
1619
1620- Fixed various core dumps caused by reference count bugs.
1621
1622Build and Ports
1623
1624- Use INSTALL_SCRIPT to install script files.
1625
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001626- New port: SCO Unixware 7, by Billy G. Allie.
1627
Guido van Rossum5b08f132001-04-16 02:05:23 +00001628- Updated RISCOS port.
1629
1630- Updated BeOS port and notes.
1631
1632- Various other porting problems resolved.
1633
1634Library
1635
1636- The TERMIOS and SOCKET modules are now truly obsolete and
1637 unnecessary. Their symbols are incorporated in the termios and
1638 socket modules.
1639
1640- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1641 better tests for pickling.
1642
1643- threading: make Condition.wait() robust against KeyboardInterrupt.
1644
1645- zipfile: add support to zipfile to support opening an archive
1646 represented by an open file rather than a file name. Fix bug where
1647 the archive was not properly closed. Fixed a bug in this bugfix
1648 where flush() was called for a read-only file.
1649
1650- imputil: added an uninstall() method to the ImportManager.
1651
1652- Canvas: fixed bugs in lower() and tkraise() methods.
1653
1654- SocketServer: API change (added overridable close_request() method)
1655 so that the TCP server can explicitly close the request.
1656
1657- pstats: Eric Raymond added a simple interactive statistics browser,
1658 invoked when the module is run as a script.
1659
1660- locale: fixed a problem in format().
1661
1662- webbrowser: made it work when the BROWSER environment variable has a
1663 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1664 KDE 2. Fixed some other nits.
1665
1666- unittest: changes to allow using a different exception than
1667 AssertionError, and added a few more function aliases. Some other
1668 small changes.
1669
1670- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1671
1672- asynchat: fixed a critical bug in asynchat that slipped through the
1673 2.1b2 release. Fixed another rare bug.
1674
1675- Fix some unqualified except: clauses (always a bad code example).
1676
1677XML
1678
1679- pyexpat: new API get_version_string().
1680
1681- Fixed some minidom bugs.
1682
1683Extensions
1684
1685- Fixed a core dump in _weakref. Removed the weakref.mapping()
1686 function (it adds nothing to the API).
1687
1688- Rationalized the use of header files in the readline module, to make
1689 it compile (albeit with some warnings) with the very recent readline
1690 4.2, without breaking for earlier versions.
1691
1692- Hopefully fixed a buffering problem in linuxaudiodev.
1693
1694- Attempted a fix to make the OpenSSL support in the socket module
1695 work again with pre-0.9.5 versions of OpenSSL.
1696
1697Tests
1698
1699- Added a test case for asynchat and asyncore.
1700
1701- Removed coupling between tests where one test failing could break
1702 another.
1703
1704Tools
1705
1706- Ping added an interactive help browser to pydoc, fixed some nits
1707 in the rest of the pydoc code, and added some features to his
1708 inspect module.
1709
1710- An updated python-mode.el version 4.1 which integrates Ken
1711 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1712 much nicer in XEmacs and Emacs. When stepping through your program
1713 with pdb, in either the shell window or the *Python* window, the
1714 source file and line will be tracked by an arrow. Very cool!
1715
1716- IDLE: syntax warnings in interactive mode are changed into errors.
1717
1718- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001719 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001720
1721- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001722
Barry Warsaw11e89c72001-04-11 20:37:57 +00001723
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001724What's New in Python 2.1 beta 2?
1725================================
1726
Guido van Rossum053ae352001-03-22 14:17:21 +00001727(Unlisted are many fixed bugs, more documentation, etc.)
1728
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001729Core language, builtins, and interpreter
1730
Guido van Rossum053ae352001-03-22 14:17:21 +00001731- The nested scopes work (enabled by "from __future__ import
1732 nested_scopes") is completed; in particular, the future now extends
1733 into code executed through exec, eval() and execfile(), and into the
1734 interactive interpreter.
1735
1736- When calling a base class method (e.g. BaseClass.__init__(self)),
1737 this is now allowed even if self is not strictly spoken a class
1738 instance (e.g. when using metaclasses or the Don Beaudry hook).
1739
1740- Slice objects are now comparable but not hashable; this prevents
1741 dict[:] from being accepted but meaningless.
1742
1743- Complex division is now calculated using less braindead algorithms.
1744 This doesn't change semantics except it's more likely to give useful
1745 results in extreme cases. Complex repr() now uses full precision
1746 like float repr().
1747
1748- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1749
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001750- It is illegal to assign to the name __debug__, which is set when the
1751 interpreter starts. It is effectively a compile-time constant.
1752
1753- A warning will be issued if a global statement for a variable
1754 follows a use or assignment of that variable.
1755
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001756Standard library
1757
Guido van Rossum053ae352001-03-22 14:17:21 +00001758- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1759 inspired by JUnit), is now part of the standard library. You now
1760 have a choice of two testing frameworks: unittest requires you to
1761 write testcases as separate code, doctest gathers them from
1762 docstrings. Both approaches have their advantages and
1763 disadvantages.
1764
1765- A new module Tix was added, which wraps the Tix extension library
1766 for Tk. With that module, it is not necessary to statically link
1767 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1768 require" command. See Demo/tix/.
1769
1770- tzparse.py is now obsolete.
1771
1772- In gzip.py, the seek() and tell() methods are removed -- they were
1773 non-functional anyway, and it's better if callers can test for their
1774 existence with hasattr().
1775
1776Python/C API
1777
1778- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1779 that's already in the dictionary during a PyDict_Next() iteration.
1780 This used to fail occasionally when a dictionary resize operation
1781 could be triggered that would rehash all the keys. All other
1782 modifications to the dictionary are still off-limits during a
1783 PyDict_Next() iteration!
1784
1785- New extended APIs related to passing compiler variables around.
1786
1787- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1788 implement isinstance() and issubclass().
1789
1790- Py_BuildValue() now has a "D" conversion to create a Python complex
1791 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001792
Fred Drake4e262a92001-03-22 18:26:47 +00001793- Extensions types which support weak references must now set the
1794 field allocated for the weak reference machinery to NULL themselves;
1795 this is done to avoid the cost of checking each object for having a
1796 weakly referencable type in PyObject_INIT(), since most types are
1797 not weakly referencable.
1798
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001799- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1800 free variables and cell variables to and from the frame's f_locals.
1801
1802- Variants of several functions defined in pythonrun.h have been added
1803 to support the nested_scopes future statement. The variants all end
1804 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1805 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1806 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001807 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001808
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001809Distutils
1810
1811- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1812 into the release tree.
1813
Tim Peters0e57abf2001-05-02 07:39:38 +00001814- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001815 (an uninstaller, more customization of the installer's display)
1816
1817- from Jack Jansen: added Mac-specific code to generate a dialog for
1818 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001819 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001820 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001821
1822- added 'platforms' and 'keywords' to the set of metadata that can be
1823 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001824
1825- applied patches from Jason Tishler to make the compiler class work with
1826 Cygwin.
1827
1828
Tim Peters2fe289a2001-03-01 22:19:38 +00001829What's New in Python 2.1 beta 1?
1830================================
Tim Petersd66595f2001-02-04 03:09:53 +00001831
1832Core language, builtins, and interpreter
1833
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001834- Following an outcry from the community about the amount of code
1835 broken by the nested scopes feature introduced in 2.1a2, we decided
1836 to make this feature optional, and to wait until Python 2.2 (or at
1837 least 6 months) to make it standard. The option can be enabled on a
1838 per-module basis by adding "from __future__ import nested_scopes" at
1839 the beginning of a module (before any other statements, but after
1840 comments and an optional docstring). See PEP 236 (Back to the
1841 __future__) for a description of the __future__ statement. PEP 227
1842 (Statically Nested Scopes) has been updated to reflect this change,
1843 and to clarify the semantics in a number of endcases.
1844
1845- The nested scopes code, when enabled, has been hardened, and most
1846 bugs and memory leaks in it have been fixed.
1847
1848- Compile-time warnings are now generated for a number of conditions
1849 that will break or change in meaning when nested scopes are enabled:
1850
1851 - Using "from...import *" or "exec" without in-clause in a function
1852 scope that also defines a lambda or nested function with one or
1853 more free (non-local) variables. The presence of the import* or
1854 bare exec makes it impossible for the compiler to determine the
1855 exact set of local variables in the outer scope, which makes it
1856 impossible to determine the bindings for free variables in the
1857 inner scope. To avoid the warning about import *, change it into
1858 an import of explicitly name object, or move the import* statement
1859 to the global scope; to avoid the warning about bare exec, use
1860 exec...in... (a good idea anyway -- there's a possibility that
1861 bare exec will be deprecated in the future).
1862
1863 - Use of a global variable in a nested scope with the same name as a
1864 local variable in a surrounding scope. This will change in
1865 meaning with nested scopes: the name in the inner scope will
1866 reference the variable in the outer scope rather than the global
1867 of the same name. To avoid the warning, either rename the outer
1868 variable, or use a global statement in the inner function.
1869
Neil Schemenauera35c6882001-02-27 04:45:05 +00001870- An optional object allocator has been included. This allocator is
1871 optimized for Python objects and should be faster and use less memory
1872 than the standard system allocator. It is not enabled by default
1873 because of possible thread safety problems. The allocator is only
1874 protected by the Python interpreter lock and it is possible that some
1875 extension modules require a thread safe allocator. The object
1876 allocator can be enabled by providing the "--with-pymalloc" option to
1877 configure.
1878
Tim Petersd66595f2001-02-04 03:09:53 +00001879Standard library
1880
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001881- pyexpat now detects the expat version if expat.h defines it. A
1882 number of additional handlers are provided, which are only available
1883 since expat 1.95. In addition, the methods SetParamEntityParsing and
1884 GetInputContext of Parser objects are available with 1.95.x
1885 only. Parser objects now provide the ordered_attributes and
1886 specified_attributes attributes. A new module expat.model was added,
1887 which offers a number of additional constants if 1.95.x is used.
1888
1889- xml.dom offers the new functions registerDOMImplementation and
1890 getDOMImplementation.
1891
1892- xml.dom.minidom offers a toprettyxml method. A number of DOM
1893 conformance issues have been resolved. In particular, Element now
1894 has an hasAttributes method, and the handling of namespaces was
1895 improved.
1896
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001897- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1898 getting information about live Python code, and pydoc.py, a module
1899 for interactively converting docstrings to HTML or text.
1900 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001901 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001902 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1903 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001904
Tim Peters1eff7962001-03-01 02:31:33 +00001905- New library module difflib.py, primarily packaging the SequenceMatcher
1906 class at the heart of the popular ndiff.py file-comparison tool.
1907
1908- doctest.py (a framework for verifying Python code examples in docstrings)
1909 is now part of the std library.
1910
Tim Petersd66595f2001-02-04 03:09:53 +00001911Windows changes
1912
Guido van Rossume3955a82001-03-02 14:05:59 +00001913- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1914 small GUI that lets you browse the module docstrings using your
1915 default web browser.
1916
Tim Peters1eff7962001-03-01 02:31:33 +00001917- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1918 Platforms) is implemented. See
1919
1920 http://python.sourceforge.net/peps/pep-0235.html
1921
1922 for full details, especially the "Current Lower-Left Semantics" section.
1923 The new Windows import rules are simpler than before:
1924
1925 A. If the PYTHONCASEOK environment variable exists, same as
1926 before: silently accept the first case-insensitive match of any
1927 kind; raise ImportError if none found.
1928
1929 B. Else search sys.path for the first case-sensitive match; raise
1930 ImportError if none found.
1931
1932 The same rules have been implented on other platforms with case-
1933 insensitive but case-preserving filesystems too (including Cygwin, and
1934 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001935
Tim Peters25a9ce32001-02-19 07:06:36 +00001936- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1937 what it's supposed to do (and does do under NT and 2000) via direct
1938 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001939 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001940 all Win9x systems before.
1941
Tim Peters1eff7962001-03-01 02:31:33 +00001942- Build: Subproject _test (effectively) renamed to _testcapi.
1943
Tim Peters2fe289a2001-03-01 22:19:38 +00001944New platforms
1945
1946- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1947 Thanks to Steven Majewski!
1948
1949- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1950 Tishler!
1951
Guido van Rossum9089b272001-03-02 06:49:50 +00001952- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1953 Schwertberger! See RISCOS/README for more information -- it seems
1954 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001955 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001956
Tim Peters25a9ce32001-02-19 07:06:36 +00001957
Tim Petersd7b5e882001-01-25 03:36:26 +00001958What's New in Python 2.1 alpha 2?
1959=================================
Tim Peters40ead762001-01-27 05:35:26 +00001960
Tim Petersd7b5e882001-01-25 03:36:26 +00001961Core language, builtins, and interpreter
1962
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001963- Scopes nest. If a name is used in a function or class, but is not
1964 local, the definition in the nearest enclosing function scope will
1965 be used. One consequence of this change is that lambda statements
1966 could reference variables in the namespaces where the lambda is
1967 defined. In some unusual cases, this change will break code.
1968
1969 In all previous version of Python, names were resolved in exactly
1970 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001971 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001972 function A is defined within a function B, the names bound in B are
1973 not visible in A. The new rules make names bound in B visible in A,
1974 unless A contains a name binding that hides the binding in B.
1975
1976 Section 4.1 of the reference manual describes the new scoping rules
1977 in detail. The test script in Lib/test/test_scope.py demonstrates
1978 some of the effects of the change.
1979
1980 The new rules will cause existing code to break if it defines nested
1981 functions where an outer function has local variables with the same
1982 name as globals or builtins used by the inner function. Example:
1983
1984 def munge(str):
1985 def helper(x):
1986 return str(x)
1987 if type(str) != type(''):
1988 str = helper(str)
1989 return str.strip()
1990
1991 Under the old rules, the name str in helper() is bound to the
1992 builtin function str(). Under the new rules, it will be bound to
1993 the argument named str and an error will occur when helper() is
1994 called.
1995
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001996- The compiler will report a SyntaxError if "from ... import *" occurs
1997 in a function or class scope. The language reference has documented
1998 that this case is illegal, but the compiler never checked for it.
1999 The recent introduction of nested scope makes the meaning of this
2000 form of name binding ambiguous. In a future release, the compiler
2001 may allow this form when there is no possibility of ambiguity.
2002
Tim Peters40ead762001-01-27 05:35:26 +00002003- repr(string) is easier to read, now using hex escapes instead of octal,
2004 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2005
2006 >>> "\texample \r\n" + chr(0) + chr(255)
2007 '\texample \r\n\x00\xff' # in 2.1
2008 '\011example \015\012\000\377' # in 2.0
2009
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002010- Functions are now compared and hashed by identity, not by value, since
2011 the func_code attribute is writable.
2012
Fred Drakefb9d7122001-02-01 20:00:40 +00002013- Weak references (PEP 205) have been added. This involves a few
2014 changes in the core, an extension module (_weakref), and a Python
2015 module (weakref). The weakref module is the public interface. It
2016 includes support for "explicit" weak references, proxy objects, and
2017 mappings with weakly held values.
2018
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002019- A 'continue' statement can now appear in a try block within the body
2020 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002021 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002022
Tim Petersd7b5e882001-01-25 03:36:26 +00002023Standard library
2024
Barry Warsaw30dbd142001-01-31 22:14:01 +00002025- mailbox.py now has a new class, PortableUnixMailbox which is
2026 identical to UnixMailbox but uses a more portable scheme for
2027 determining From_ separators. Also, the constructors for all the
2028 classes in this module have a new optional `factory' argument, which
2029 is a callable used when new message classes must be instantiated by
2030 the next() method.
2031
Tim Petersd7b5e882001-01-25 03:36:26 +00002032- random.py is now self-contained, and offers all the functionality of
2033 the now-deprecated whrandom.py. See the docs for details. random.py
2034 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002035 and restoring the internal state of the generator; and jumpahead(n),
2036 for quickly forcing the internal state to be the same as if n calls to
2037 random() had been made. The latter is particularly useful for multi-
2038 threaded programs, creating one instance of the random.Random() class for
2039 each thread, then using .jumpahead() to force each instance to use a
2040 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002041
Tim Peters0de88fc2001-02-01 04:59:18 +00002042- random.py's seed() function is new. For bit-for-bit compatibility with
2043 prior releases, use the whseed function instead. The new seed function
2044 addresses two problems: (1) The old function couldn't produce more than
2045 about 2**24 distinct internal states; the new one about 2**45 (the best
2046 that can be done in the Wichmann-Hill generator). (2) The old function
2047 sometimes produced identical internal states when passed distinct
2048 integers, and there was no simple way to predict when that would happen;
2049 the new one guarantees to produce distinct internal states for all
2050 arguments in [0, 27814431486576L).
2051
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002052- The socket module now supports raw packets on Linux. The socket
2053 family is AF_PACKET.
2054
Tim Peters9ea17ac2001-02-02 05:57:15 +00002055- test_capi.py is a start at running tests of the Python C API. The tests
2056 are implemented by the new Modules/_testmodule.c.
2057
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002058- A new extension module, _symtable, provides provisional access to the
2059 internal symbol table used by the Python compiler. A higher-level
2060 interface will be added on top of _symtable in a future release.
2061
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002062- Removed the obsolete soundex module.
2063
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002064- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2065 the isSameNode method; NamedNodeMap the get method.
2066
2067- xml.sax.expatreader supports the lexical handler property; it
2068 generates comment, startCDATA, and endCDATA events.
2069
Tim Petersee826f82001-01-31 19:39:44 +00002070Windows changes
2071
2072- Build procedure: the zlib project is built in a different way that
2073 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002074 the zlib binary used. See PCbuild\readme.txt for details. Your old
2075 zlib-related directories can be deleted; you'll need to download fresh
2076 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002077
Tim Peters9ea17ac2001-02-02 05:57:15 +00002078- Build: New subproject _test for the benefit of test_capi.py (see above).
2079
Tim Petersb16c56f2001-02-02 21:24:51 +00002080- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2081 interface to some Python compiler internals).
2082
2083- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002084 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002085
Tim Petersa3a3a032000-11-30 05:22:44 +00002086What's New in Python 2.1 alpha 1?
2087=================================
2088
2089Core language, builtins, and interpreter
2090
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002091- There is a new Unicode companion to the PyObject_Str() API
2092 called PyObject_Unicode(). It behaves in the same way as the
2093 former, but assures that the returned value is an Unicode object
2094 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002095
Guido van Rossumf98eda02001-01-17 15:54:45 +00002096- The comparison operators support "rich comparison overloading" (PEP
2097 207). C extension types can provide a rich comparison function in
2098 the new tp_richcompare slot in the type object. The cmp() function
2099 and the C function PyObject_Compare() first try the new rich
2100 comparison operators before trying the old 3-way comparison. There
2101 is also a new C API PyObject_RichCompare() (which also falls back on
2102 the old 3-way comparison, but does not constrain the outcome of the
2103 rich comparison to a Boolean result).
2104
2105 The rich comparison function takes two objects (at least one of
2106 which is guaranteed to have the type that provided the function) and
2107 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2108 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2109 object, which may be NotImplemented (in which case the tp_compare
2110 slot function is used as a fallback, if defined).
2111
2112 Classes can overload individual comparison operators by defining one
2113 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002114 __ge__. There are no explicit "reflected argument" versions of
2115 these; instead, __lt__ and __gt__ are each other's reflection,
2116 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2117 reflection (similar at the C level). No other implications are
2118 made; in particular, Python does not assume that == is the Boolean
2119 inverse of !=, or that < is the Boolean inverse of >=. This makes
2120 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002121
2122 Classes or types that want to implement (in)equality tests but not
2123 the ordering operators (i.e. unordered types) should implement ==
2124 and !=, and raise an error for the ordering operators.
2125
Guido van Rossuma88479f2001-01-18 14:28:08 +00002126 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002127 Boolean; e.g. a matrix type might want to return a matrix of bits
2128 for A < B, giving elementwise comparisons. Such types should ensure
2129 that any interpretation of their value in a Boolean context raises
2130 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2131 at the C level) to always raise an exception.
2132
Guido van Rossuma88479f2001-01-18 14:28:08 +00002133- Complex numbers use rich comparisons to define == and != but raise
2134 an exception for <, <=, > and >=. Unfortunately, this also means
2135 that cmp() of two complex numbers raises an exception when the two
2136 numbers differ. Since it is not mathematically meaningful to compare
2137 complex numbers except for equality, I hope that this doesn't break
2138 too much code.
2139
Tim Peters3389f192001-02-18 08:48:49 +00002140- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002141 not defined by the language, other than that it's arbitrary but
2142 consistent (see the Reference Manual). An implementation detail changed
2143 in 2.1a1 such that None now compares less than any other object. Code
2144 relying on this new behavior (like code that relied on the previous
2145 behavior) does so at its own risk.
2146
Barry Warsaw573b5412001-01-15 20:43:18 +00002147- Functions and methods now support getting and setting arbitrarily
2148 named attributes (PEP 232). Functions have a new __dict__
2149 (a.k.a. func_dict) which hold the function attributes. Methods get
2150 and set attributes on their underlying im_func. It is a TypeError
2151 to set an attribute on a bound method.
2152
Guido van Rossum051e3352001-01-15 19:11:10 +00002153- The xrange() object implementation has been improved so that
2154 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2155 limitation that in this case len(xrange(sys.maxint)) can't be
2156 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2157 work fine as long as the index i doesn't actually reach 2**31.
2158 (Python uses regular ints for sequence and string indices; fixing
2159 that is much more work.)
2160
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002161- Two changes to from...import:
2162
Guido van Rossumba381232001-02-03 15:06:40 +00002163 1) "from M import X" now works even if (after loading module M)
2164 sys.modules['M'] is not a real module; it's basically a getattr()
2165 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002166
2167 2) "from M import *" now looks for M.__all__ to decide which names to
2168 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2169 filters out names starting with '_' as before. Whether or not
2170 __all__ exists, there's no restriction on the type of M.
2171
Guido van Rossumf61f1662001-01-10 20:13:55 +00002172- File objects have a new method, xreadlines(). This is the fastest
2173 way to iterate over all lines in a file:
2174
2175 for line in file.xreadlines():
2176 ...do something to line...
2177
2178 See the xreadlines module (mentioned below) for how to do this for
2179 other file-like objects.
2180
2181- Even if you don't use file.xreadlines(), you may expect a speedup on
2182 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002183 quite a bit in platform-specific ways: on systems (like Linux) that
2184 support flockfile(), getc_unlocked(), and funlockfile(), those are
2185 used by default. On systems (like Windows) without getc_unlocked(),
2186 a complicated (but still thread-safe) method using fgets() is used by
2187 default.
2188
Tim Petersd52269b2001-01-25 06:23:18 +00002189 You can force use of the fgets() method by #define'ing
2190 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002191 getc_unlocked()).
2192
Tim Petersd52269b2001-01-25 06:23:18 +00002193 You can force fgets() not to be used by #define'ing
2194 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002195 test_bufio.py fails -- and let us know if it does!).
2196
2197- In addition, the fileinput module, while still slower than the other
2198 methods on most platforms, has been sped up too, by using
2199 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002200
2201- Support for run-time warnings has been added, including a new
2202 command line option (-W) to specify the disposition of warnings.
2203 See the description of the warnings module below.
2204
2205- Extensive changes have been made to the coercion code. This mostly
2206 affects extension modules (which can now implement mixed-type
2207 numerical operators without having to use coercion), but
2208 occasionally, in boundary cases the coercion semantics have changed
2209 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002210 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002211 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002212 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002213
Guido van Rossumf98eda02001-01-17 15:54:45 +00002214- In connection with the coercion changes, a new built-in singleton
2215 object, NotImplemented is defined. This can be returned for
2216 operations that wish to indicate they are not implemented for a
2217 particular combination of arguments. From C, this is
2218 Py_NotImplemented.
2219
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002220- The interpreter accepts now bytecode files on the command line even
2221 if they do not have a .pyc or .pyo extension. On Linux, after executing
2222
Martin v. Löwise214baa2001-02-04 22:37:56 +00002223import imp,sys,string
2224magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2225reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2226open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002227
2228 any byte code file can be used as an executable (i.e. as an argument
2229 to execve(2)).
2230
Tim Peters9940b802000-12-01 07:59:35 +00002231- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002232 character. In 1.6 and earlier, they never produced a sign,
2233 and raised an error if the value of the long was too large
2234 to fit in a Python int. In 2.0, they produced a sign if and
2235 only if too large to fit in an int. This was inconsistent
2236 across platforms (because the size of an int varies across
2237 platforms), and inconsistent with hex() and oct(). Example:
2238
2239 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002240 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002241 'ffffffbe' # in 2.0 and before, on 32-bit machines
2242 >>> hex(-0x42L)
2243 '-0x42L' # in all versions of Python
2244
Tim Peters9940b802000-12-01 07:59:35 +00002245 The behavior of %d formats for negative Python longs remains
2246 the same as in 2.0 (although in 1.6 and before, they raised
2247 an error if the long didn't fit in a Python int).
2248
2249 %u formats don't make sense for Python longs, but are allowed
2250 and treated the same as %d in 2.1. In 2.0, a negative long
2251 formatted via %u produced a sign if and only if too large to
2252 fit in an int. In 1.6 and earlier, a negative long formatted
2253 via %u raised an error if it was too big to fit in an int.
2254
Guido van Rossum3661d392000-12-12 22:10:31 +00002255- Dictionary objects have an odd new method, popitem(). This removes
2256 an arbitrary item from the dictionary and returns it (in the form of
2257 a (key, value) pair). This can be useful for algorithms that use a
2258 dictionary as a bag of "to do" items and repeatedly need to pick one
2259 item. Such algorithms normally end up running in quadratic time;
2260 using popitem() they can usually be made to run in linear time.
2261
Tim Peters36cdad12000-12-29 02:06:45 +00002262Standard library
2263
Thomas Woutersfe385252001-01-19 23:16:56 +00002264- In the time module, the time argument to the functions strftime,
2265 localtime, gmtime, asctime and ctime is now optional, defaulting to
2266 the current time (in the local timezone).
2267
Guido van Rossumda91f222001-01-15 16:36:08 +00002268- The ftplib module now defaults to passive mode, which is deemed a
2269 more useful default given that clients are often inside firewalls
2270 these days. Note that this could break if ftplib is used to connect
2271 to a *server* that is inside a firewall, from outside; this is
2272 expected to be a very rare situation. To fix that, you can call
2273 ftp.set_pasv(0).
2274
Martin v. Löwis10a27872001-01-13 09:54:41 +00002275- The module site now treats .pth files not only for path configuration,
2276 but also supports extensions to the initialization code: Lines starting
2277 with import are executed.
2278
Guido van Rossumf61f1662001-01-10 20:13:55 +00002279- There's a new module, warnings, which implements a mechanism for
2280 issuing and filtering warnings. There are some new built-in
2281 exceptions that serve as warning categories, and a new command line
2282 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2283 turns warnings into errors). warnings.warn(message[, category])
2284 issues a warning message; this can also be called from C as
2285 PyErr_Warn(category, message).
2286
2287- A new module xreadlines was added. This exports a single factory
2288 function, xreadlines(). The intention is that this code is the
2289 absolutely fastest way to iterate over all lines in an open
2290 file(-like) object:
2291
2292 import xreadlines
2293 for line in xreadlines.xreadlines(file):
2294 ...do something to line...
2295
2296 This is equivalent to the previous the speed record holder using
2297 file.readlines(sizehint). Note that if file is a real file object
2298 (as opposed to a file-like object), this is equivalent:
2299
2300 for line in file.xreadlines():
2301 ...do something to line...
2302
Tim Peters36cdad12000-12-29 02:06:45 +00002303- The bisect module has new functions bisect_left, insort_left,
2304 bisect_right and insort_right. The old names bisect and insort
2305 are now aliases for bisect_right and insort_right. XXX_right
2306 and XXX_left methods differ in what happens when the new element
2307 compares equal to one or more elements already in the list: the
2308 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002309 right. Code that doesn't care where equal elements end up should
2310 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002311
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002312- The new curses.panel module wraps the panel library that forms part
2313 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2314
Guido van Rossumf61f1662001-01-10 20:13:55 +00002315- The SocketServer module now sets the allow_reuse_address flag by
2316 default in the TCPServer class.
2317
2318- A new function, sys._getframe(), returns the stack frame pointer of
2319 the caller. This is intended only as a building block for
2320 higher-level mechanisms such as string interpolation.
2321
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002322- The pyexpat module supports a number of new handlers, which are
2323 available only in expat 1.2. If invocation of a callback fails, it
2324 will report an additional frame in the traceback. Parser objects
2325 participate now in garbage collection. If expat reports an unknown
2326 encoding, pyexpat will try to use a Python codec; that works only
2327 for single-byte charsets. The parser type objects is exposed as
2328 XMLParserObject.
2329
2330- xml.dom now offers standard definitions for symbolic node type and
2331 exception code constants, and a hierarchy of DOM exceptions. minidom
2332 was adjusted to use them.
2333
2334- The conformance of xml.dom.minidom to the DOM specification was
2335 improved. It detects a number of additional error cases; the
2336 previous/next relationship works even when the tree is modified;
2337 Node supports the normalize() method; NamedNodeMap, DocumentType and
2338 DOMImplementation classes were added; Element supports the
2339 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2340 method.
2341
Guido van Rossumf61f1662001-01-10 20:13:55 +00002342Build issues
2343
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002344- For Unix (and Unix-compatible) builds, configuration and building of
2345 extension modules is now greatly automated. Rather than having to
2346 edit the Modules/Setup file to indicate which modules should be
2347 built and where their include files and libraries are, a
2348 distutils-based setup.py script now takes care of building most
2349 extension modules. All extension modules built this way are built
2350 as shared libraries. Only a few modules that must be linked
2351 statically are still listed in the Setup file; you won't need to
2352 edit their configuration.
2353
2354- Python should now build out of the box on Cygwin. If it doesn't,
2355 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002356
2357- Python now always uses its own (renamed) implementation of getopt()
2358 -- there's too much variation among C library getopt()
2359 implementations.
2360
2361- C++ compilers are better supported; the CXX macro is always set to a
2362 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002363
Tim Petersd92dfe02000-12-12 01:18:41 +00002364Windows changes
2365
2366- select module: By default under Windows, a select() call
2367 can specify no more than 64 sockets. Python now boosts
2368 this Microsoft default to 512. If you need even more than
2369 that, see the MS docs (you'll need to #define FD_SETSIZE
2370 and recompile Python from source).
2371
Guido van Rossumf61f1662001-01-10 20:13:55 +00002372- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2373 subdirectory is no more!
2374
Tim Petersa3a3a032000-11-30 05:22:44 +00002375
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002376What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002377=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002378
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002379Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002380changes are in the file HISTORY. If you are making the jump directly
2381from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2382HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002383
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002384Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2385the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2386http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002387
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002388--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002389
2390======================================================================
2391
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002392What's new in 2.0 (since release candidate 1)?
2393==============================================
2394
2395Standard library
2396
2397- The copy_reg module was modified to clarify its intended use: to
2398 register pickle support for extension types, not for classes.
2399 pickle() will raise a TypeError if it is passed a class.
2400
2401- Fixed a bug in gettext's "normalize and expand" code that prevented
2402 it from finding an existing .mo file.
2403
2404- Restored support for HTTP/0.9 servers in httplib.
2405
Tim Peters989b7b92000-10-16 20:24:53 +00002406- The math module was changed to stop raising OverflowError in case of
2407 underflow, and return 0 instead in underflow cases. Whether Python
2408 used to raise OverflowError in case of underflow was platform-
2409 dependent (it did when the platform math library set errno to ERANGE
2410 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002411
2412- Fixed a bug in StringIO that occurred when the file position was not
2413 at the end of the file and write() was called with enough data to
2414 extend past the end of the file.
2415
2416- Fixed a bug that caused Tkinter error messages to get lost on
2417 Windows. The bug was fixed by replacing direct use of
2418 interp->result with Tcl_GetStringResult(interp).
2419
2420- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2421 redirect response.
2422
2423- Several changes were made to distutils: Some debugging code was
2424 removed from util. Fixed the installer used when an external zip
2425 program (like WinZip) is not found; the source code for this
2426 installer is in Misc/distutils. check_lib() was modified to behave
2427 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2428 test for whether installed modules are on sys.path was changed to
2429 use both normcase() and normpath().
2430
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002431- Several minor bugs were fixed in the xml package (the minidom,
2432 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002433
2434- The regression test driver (regrtest.py) behavior when invoked with
2435 -l changed: It now reports a count of objects that are recognized as
2436 garbage but not freed by the garbage collector.
2437
Tim Peters989b7b92000-10-16 20:24:53 +00002438- The regression test for the math module was changed to test
2439 exceptional behavior when the test is run in verbose mode. Python
2440 cannot yet guarantee consistent exception behavior across platforms,
2441 so the exception part of test_math is run only in verbose mode, and
2442 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002443
2444Internals
2445
2446- PyOS_CheckStack() has been disabled on Win64, where it caused
2447 test_sre to fail.
2448
2449Build issues
2450
2451- Changed compiler flags, so that gcc is always invoked with -Wall and
2452 -Wstrict-prototypes. Users compiling Python with GCC should see
2453 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002454 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002455 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002456
Tim Petersa3a3a032000-11-30 05:22:44 +00002457- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002458
2459Tools and other miscellany
2460
2461- The compiler in Tools/compiler was updated to support the new
2462 language features introduced in 2.0: extended print statement, list
2463 comprehensions, and augmented assignments. The new compiler should
2464 also be backwards compatible with Python 1.5.2; the compiler will
2465 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002466 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002467
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002468What's new in 2.0 release candidate 1 (since beta 2)?
2469=====================================================
2470
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002471What is release candidate 1?
2472
2473We believe that release candidate 1 will fix all known bugs that we
2474intend to fix for the 2.0 final release. This release should be a bit
2475more stable than the previous betas. We would like to see even more
2476widespread testing before the final release, so we are producing this
2477release candidate. The final release will be exactly the same unless
2478any show-stopping (or brown bag) bugs are found by testers of the
2479release candidate.
2480
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002481All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002482to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002483
2484Core language, builtins, and interpreter
2485
2486- A bug that caused crashes when __coerce__ was used with augmented
2487 assignment, e.g. +=, was fixed.
2488
2489- Raise ZeroDivisionError when raising zero to a negative number,
2490 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2491 power operator and the result of math.pow(0.0, -2.0) will vary by
2492 platform. On Linux, it raises a ValueError.
2493
2494- A bug in Unicode string interpolation was fixed that occasionally
2495 caused errors with formats including "%%". For example, the
2496 following expression "%% %s" % u"abc" no longer raises a TypeError.
2497
2498- Compilation of deeply nested expressions raises MemoryError instead
2499 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2500
2501- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2502 rendering them useless. They are now written in binary mode again.
2503
2504Standard library
2505
2506- Keyword arguments are now accepted for most pattern and match object
2507 methods in SRE, the standard regular expression engine.
2508
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002509- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002510 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002511
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002512- Several bugs in the Unicode handling and error handling in _tkinter
2513 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002514
2515- Fix memory management errors in Merge() and Tkapp_Call() routines.
2516
2517- Several changes were made to cStringIO to make it compatible with
2518 the file-like object interface and with StringIO. If operations are
2519 performed on a closed object, an exception is raised. The truncate
2520 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002521 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002522
2523- There were many changes made to the linuxaudiodev module and its
2524 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002525 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002526
2527 Note that this module is named poorly, because it should work
2528 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002529 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002530
2531 The module now raises exceptions when errors occur instead of
2532 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2533 audio) and defines a getptr() method that calls the
2534 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2535
2536- The library_version attribute, introduced in an earlier beta, was
2537 removed because it can not be supported with early versions of the C
2538 readline library, which provides no way to determine the version at
2539 compile-time.
2540
2541- The binascii module is now enabled on Win64.
2542
Tim Peters46446d62000-10-09 21:19:31 +00002543- tokenize.py no longer suffers "recursion depth" errors when parsing
2544 programs with very long string literals.
2545
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002546Internals
2547
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002548- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002549 which is called when the interpreter starts up to determine where
2550 the standard library is installed. These vulnerabilities affect all
2551 previous versions of Python and can be exploited by setting very
2552 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2553 setuid Python script, although use of the wrapper in
2554 Misc/setuid-prog.c will eliminate the vulnerability.
2555
2556- Fixed garbage collection bugs in instance creation that were
2557 triggered when errors occurred during initialization. The solution,
2558 applied in cPickle and in PyInstance_New(), is to call
2559 PyObject_GC_Init() after the initialization of the object's
2560 container attributes is complete.
2561
2562- pyexpat adds definitions of PyModule_AddStringConstant and
2563 PyModule_AddObject if the Python version is less than 2.0, which
2564 provides compatibility with PyXML on Python 1.5.2.
2565
2566- If the platform has a bogus definition for LONG_BIT (the number of
2567 bits in a long), an error will be reported at compile time.
2568
2569- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2570 collection crashes and possibly other, unreported crashes.
2571
2572- Fixed a memory leak in _PyUnicode_Fini().
2573
2574Build issues
2575
2576- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002577 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002578 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002579
2580- The mmap.PAGESIZE constant is now initialized using sysconf when
2581 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2582
2583- The md5 file should now compile on all platforms.
2584
2585- The select module now compiles on platforms that do not define
2586 POLLRDNORM and related constants.
2587
2588- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002589 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002590
Jeremy Hylton10921202000-10-09 18:34:12 +00002591- BeOS: A number of changes were made to the build and installation
2592 process. ar-fake now operates on a directory of object files.
2593 dl_export.h is gone, and its macros now appear on the mwcc command
2594 line during build on PPC BeOS.
2595
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002596- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002597 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002598
2599- Cygwin: Support for shared libraries, Tkinter, and sockets.
2600
2601- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2602
2603Tools and other miscellany
2604
2605- Removed debugging prints from main used with freeze.
2606
Tim Peters46446d62000-10-09 21:19:31 +00002607- IDLE auto-indent no longer crashes when it encounters Unicode
2608 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002609
2610What's new in 2.0 beta 2 (since beta 1)?
2611========================================
2612
2613Core language, builtins, and interpreter
2614
Tim Peters482c0212000-09-26 06:33:09 +00002615- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002616 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002617
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002618- Add -h and -V command line options to print the usage message and
2619 Python version number and exit immediately.
2620
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002621- eval() and exec accept Unicode objects as code parameters.
2622
2623- getattr() and setattr() now also accept Unicode objects for the
2624 attribute name, which are converted to strings using the default
2625 encoding before lookup.
2626
2627- Multiplication on string and Unicode now does proper bounds
2628 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2629 string is too long."
2630
2631- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002632 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002633
Jeremy Hylton1b618592000-09-26 05:32:36 +00002634
2635Standard library and extensions
2636
Guido van Rossum5b08f132001-04-16 02:05:23 +00002637- socket module: the OpenSSL code now adds support for RAND_status()
2638 and EGD (Entropy Gathering Device).
2639
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002640- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002641 argument checking; it still takes no arguments.
2642
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002643- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002644
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002645- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002646
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002647- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002648
2649- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002650 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002651
2652- copy: Copy Unicode objects atomically.
2653
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002654- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002655
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002656- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002657
Fred Drake67233bc2000-09-26 16:40:27 +00002658- dbm: Add get() and setdefault() methods to dbm object. Add constant
2659 `library' to module that names the library used. Added doc strings
2660 and method names to error messages. Uses configure to determine
2661 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2662 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002663
2664- distutils: Update to version 0.9.3.
2665
2666- dl: Add several dl.RTLD_ constants.
2667
2668- fpectl: Now supported on FreeBSD.
2669
2670- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2671 found by the collector will be saved in gc.garbage. This is useful
2672 for debugging a program that creates reference cycles.
2673
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002674- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002675 of HTTP class. Do not close socket on zero-length response. Do not
2676 crash when server sends invalid content-length header.
2677
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002678- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002679
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002680- marshal: When reading a short, sign-extend on platforms where shorts
2681 are bigger than 16 bits. When reading a long, repair the unportable
2682 sign extension that was being done for 64-bit machines. (It assumed
2683 that signed right shift sign-extends.)
2684
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002685- operator: Add contains(), invert(), __invert__() as aliases for
2686 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002687
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002688- os: Add support for popen2() and popen3() on all platforms where
2689 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002690
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002691- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002692 clicking on a file in Explorer (or passing the file name to the
2693 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002694
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002695- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002696 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002697
2698- pickle: Now raises ValueError when an invalid pickle that contains
2699 a non-string repr where a string repr was expected. This behavior
2700 matches cPickle.
2701
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002702- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002703
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002704- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002705
2706- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002707 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002708 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002709
2710- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002711 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002712
2713- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002714 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002715 few cycles during startup since the first call to
2716 setdefaultencoding() will initialize the codec registry and the
2717 encodings package.
2718
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002719- socket: Support for size hint in readlines() method of object returned
2720 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002722- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002723 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002724 is followed by whitespace.
2725
Tim Petersa3a3a032000-11-30 05:22:44 +00002726- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002727
2728- struct: Check ranges for bytes and shorts.
2729
2730- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002731 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002732
2733- Tkinter: Image objects are now guaranteed to have unique ids. Set
2734 event.delta to zero if Tk version doesn't support mousewheel.
2735 Removed some debugging prints.
2736
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002737- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002738
Fred Drake67233bc2000-09-26 16:40:27 +00002739- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002740 which works around a bug in Norton AntiVirus 2000 that leads directly
2741 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002742
2743- xml: New version detection code allows PyXML to override standard
2744 XML package if PyXML version is greater than 0.6.1.
2745
Fred Drake64bb3802000-09-26 16:21:35 +00002746- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2747 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2748 tree only for nodes which are sufficiently interesting to a specific
2749 application. Does not provide the HTML-specific extensions. Still
2750 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002751
Fred Drake64bb3802000-09-26 16:21:35 +00002752- xml.sax: SAX 2 support for Python, including all the handler
2753 interfaces needed to process XML 1.0 compliant XML. Some
2754 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002755
Fred Drake64bb3802000-09-26 16:21:35 +00002756- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2757 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002758
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002759
Jeremy Hylton1b618592000-09-26 05:32:36 +00002760C API
2761
2762- Add three new convenience functions for module initialization --
2763 PyModule_AddObject(), PyModule_AddIntConstant(), and
2764 PyModule_AddStringConstant().
2765
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002766- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002767 removed and add #error to Python.h if NULL isn't defined after
2768 #include of stdio.h.
2769
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002770- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002771 backwards compatibility (at the source level) with old extensions.
2772
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002773- A wrapper API was added for signal() and sigaction(). Instead of
2774 either function, always use PyOS_getsig() to get a signal handler
2775 and PyOS_setsig() to set one. A new convenience typedef
2776 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002777
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002778- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002779 internal data buffer and size of a string object -- or the default
2780 encoded version of a Unicode object.
2781
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002782- PyString_Size() and PyString_AsString() accept Unicode objects.
2783
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002784- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002785 exists). INT_MAX and LONG_MAX will always be defined, even if
2786 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002787
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002788- PyFloat_FromString takes a second argument, pend, that was
2789 effectively useless. It is now officially useless but preserved for
2790 backwards compatibility. If the pend argument is not NULL, *pend is
2791 set to NULL.
2792
2793- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2794 for the attribute name. See note on getattr() above.
2795
2796- A few bug fixes to argument processing for Unicode.
2797 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2798 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2799 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002800 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002801
2802- Py_BuildValue accepts B format (for bgen-generated code).
2803
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002804
Jeremy Hylton1b618592000-09-26 05:32:36 +00002805Internals
2806
2807- On Unix, fix code for finding Python installation directory so that
2808 it works when argv[0] is a relative path.
2809
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002810- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002811 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002812 rather than by generating a copy of the object.
2813
Tim Peters482c0212000-09-26 06:33:09 +00002814- Several of the internal Unicode tables are much smaller now, and
2815 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002816
Jeremy Hylton97693b02000-09-26 17:42:51 +00002817- In the garbage collector: Fixed bug in collection of tuples. Fixed
2818 bug that caused some instances to be removed from the container set
2819 while they were still live. Fixed parsing in gc.set_debug() for
2820 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002821
2822- Fixed refcount problem in instance deallocation that only occurred
2823 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2824
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002825- On Windows, getpythonregpath is now protected against null data in
2826 registry key.
2827
2828- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002829 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002830
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002831
Jeremy Hylton1b618592000-09-26 05:32:36 +00002832Build and platform-specific issues
2833
2834- Better support of GNU Pth via --with-pth configure option.
2835
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002836- Python/C API now properly exposed to dynamically-loaded extension
2837 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002838
2839- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2840 Don't define MS_SYNC to be zero when it is undefined. Added missing
2841 prototypes in posixmodule.c.
2842
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002843- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002844 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002845
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002846- Fix largefile support on older NetBSD systems and OpenBSD by adding
2847 define for TELL64.
2848
2849
2850Tools and other miscellany
2851
2852- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2853
2854- freeze: The modulefinder now works with 2.0 opcodes.
2855
Tim Petersa3a3a032000-11-30 05:22:44 +00002856- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002857 Move hackery of sys.argv until after the Tk instance has been
2858 created, which allows the application-specific Tkinter
2859 initialization to be executed if present; also pass an explicit
2860 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002861
Jeremy Hylton1b618592000-09-26 05:32:36 +00002862
2863What's new in 2.0 beta 1?
2864=========================
2865
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002866Source Incompatibilities
2867------------------------
2868
2869None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2870such as single-argument append(), connect() and bind(), and changes to
2871str(long) and repr(float).
2872
2873
2874Binary Incompatibilities
2875------------------------
2876
2877- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2878with Python 2.0; these extensions will have to be rebuilt for Python
28792.0.
2880
2881- On Windows, attempting to import a third party extension built for
2882Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2883can do about this. Check your PYTHONPATH environment variable!
2884
2885- Python bytecode files (*.pyc and *.pyo) are not compatible between
2886releases.
2887
2888
2889Overview of Changes Since 1.6
2890-----------------------------
2891
2892There are many new modules (including brand new XML support through
2893the xml package, and i18n support through the gettext module); a list
2894of all new modules is included below. Lots of bugs have been fixed.
2895
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002896The process for making major new changes to the language has changed
2897since Python 1.6. Enhancements must now be documented by a Python
2898Enhancement Proposal (PEP) before they can be accepted.
2899
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002900There are several important syntax enhancements, described in more
2901detail below:
2902
2903 - Augmented assignment, e.g. x += 1
2904
2905 - List comprehensions, e.g. [x**2 for x in range(10)]
2906
2907 - Extended import statement, e.g. import Module as Name
2908
2909 - Extended print statement, e.g. print >> file, "Hello"
2910
2911Other important changes:
2912
2913 - Optional collection of cyclical garbage
2914
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002915Python Enhancement Proposal (PEP)
2916---------------------------------
2917
2918PEP stands for Python Enhancement Proposal. A PEP is a design
2919document providing information to the Python community, or describing
2920a new feature for Python. The PEP should provide a concise technical
2921specification of the feature and a rationale for the feature.
2922
2923We intend PEPs to be the primary mechanisms for proposing new
2924features, for collecting community input on an issue, and for
2925documenting the design decisions that have gone into Python. The PEP
2926author is responsible for building consensus within the community and
2927documenting dissenting opinions.
2928
2929The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002930
2931Augmented Assignment
2932--------------------
2933
2934This must have been the most-requested feature of the past years!
2935Eleven new assignment operators were added:
2936
Guido van Rossume905e952000-09-05 12:42:46 +00002937 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002938
2939For example,
2940
2941 A += B
2942
2943is similar to
2944
2945 A = A + B
2946
2947except that A is evaluated only once (relevant when A is something
2948like dict[index].attr).
2949
2950However, if A is a mutable object, A may be modified in place. Thus,
2951if A is a number or a string, A += B has the same effect as A = A+B
2952(except A is only evaluated once); but if a is a list, A += B has the
2953same effect as A.extend(B)!
2954
2955Classes and built-in object types can override the new operators in
2956order to implement the in-place behavior; the not-in-place behavior is
2957used automatically as a fallback when an object doesn't implement the
2958in-place behavior. For classes, the method name is derived from the
2959method name for the corresponding not-in-place operator by inserting
2960an 'i' in front of the name, e.g. __iadd__ implements in-place
2961__add__.
2962
2963Augmented assignment was implemented by Thomas Wouters.
2964
2965
2966List Comprehensions
2967-------------------
2968
2969This is a flexible new notation for lists whose elements are computed
2970from another list (or lists). The simplest form is:
2971
2972 [<expression> for <variable> in <sequence>]
2973
Guido van Rossum56db0952000-09-06 23:34:25 +00002974For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002975This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002976
2977You can also add a condition:
2978
2979 [<expression> for <variable> in <sequence> if <condition>]
2980
2981For example, [w for w in words if w == w.lower()] would yield the list
2982of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002983than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002984
2985You can also have nested for loops and more than one 'if' clause. For
2986example, here's a function that flattens a sequence of sequences::
2987
2988 def flatten(seq):
2989 return [x for subseq in seq for x in subseq]
2990
2991 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2992
2993This prints
2994
2995 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2996
2997List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002998Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002999
3000
3001Extended Import Statement
3002-------------------------
3003
3004Many people have asked for a way to import a module under a different
3005name. This can be accomplished like this:
3006
3007 import foo
3008 bar = foo
3009 del foo
3010
3011but this common idiom gets old quickly. A simple extension of the
3012import statement now allows this to be written as follows:
3013
3014 import foo as bar
3015
3016There's also a variant for 'from ... import':
3017
3018 from foo import bar as spam
3019
3020This also works with packages; e.g. you can write this:
3021
3022 import test.regrtest as regrtest
3023
3024Note that 'as' is not a new keyword -- it is recognized only in this
3025context (this is only possible because the syntax for the import
3026statement doesn't involve expressions).
3027
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003028Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003029
3030
3031Extended Print Statement
3032------------------------
3033
3034Easily the most controversial new feature, this extension to the print
3035statement adds an option to make the output go to a different file
3036than the default sys.stdout.
3037
3038For example, to write an error message to sys.stderr, you can now
3039write:
3040
3041 print >> sys.stderr, "Error: bad dog!"
3042
3043As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003044evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003045
3046 print >> None, "Hello world"
3047
3048is equivalent to
3049
3050 print "Hello world"
3051
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003052Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003053
3054
3055Optional Collection of Cyclical Garbage
3056---------------------------------------
3057
3058Python is now equipped with a garbage collector that can hunt down
3059cyclical references between Python objects. It's no replacement for
3060reference counting; in fact, it depends on the reference counts being
3061correct, and decides that a set of objects belong to a cycle if all
3062their reference counts can be accounted for from their references to
3063each other. This devious scheme was first proposed by Eric Tiedemann,
3064and brought to implementation by Neil Schemenauer.
3065
3066There's a module "gc" that lets you control some parameters of the
3067garbage collection. There's also an option to the configure script
3068that lets you enable or disable the garbage collection. In 2.0b1,
3069it's on by default, so that we (hopefully) can collect decent user
3070experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003071performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003072off by default in the final 2.0 release.
3073
3074
3075Smaller Changes
3076---------------
3077
3078A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3079map(None, seq1, seq2, ...) when the sequences have the same length;
3080i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3081the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003082zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003083
3084sys.version_info is a tuple (major, minor, micro, level, serial).
3085
3086Dictionaries have an odd new method, setdefault(key, default).
3087dict.setdefault(key, default) returns dict[key] if it exists; if not,
3088it sets dict[key] to default and returns that value. Thus:
3089
3090 dict.setdefault(key, []).append(item)
3091
3092does the same work as this common idiom:
3093
3094 if not dict.has_key(key):
3095 dict[key] = []
3096 dict[key].append(item)
3097
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003098There are two new variants of SyntaxError that are raised for
3099indentation-related errors: IndentationError and TabError.
3100
3101Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3102escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003103
3104The limits on the size of expressions and file in Python source code
3105have been raised from 2**16 to 2**32. Previous versions of Python
3106were limited because the maximum argument size the Python VM accepted
3107was 2**16. This limited the size of object constructor expressions,
3108e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3109limit was raised thanks to a patch by Charles Waldman that effectively
3110fixes the problem. It is now much more likely that you will be
3111limited by available memory than by an arbitrary limit in Python.
3112
3113The interpreter's maximum recursion depth can be modified by Python
3114programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3115limit is the maximum number of recursive calls that can be made by
3116Python code. The limit exists to prevent infinite recursion from
3117overflowing the C stack and causing a core dump. The default value is
31181000. The maximum safe value for a particular platform can be found
3119by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003120
3121New Modules and Packages
3122------------------------
3123
3124atexit - for registering functions to be called when Python exits.
3125
3126imputil - Greg Stein's alternative API for writing custom import
3127hooks.
3128
3129pyexpat - an interface to the Expat XML parser, contributed by Paul
3130Prescod.
3131
3132xml - a new package with XML support code organized (so far) in three
3133subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3134would fill a volume. There's a special feature whereby a
3135user-installed package named _xmlplus overrides the standard
3136xmlpackage; this is intended to give the XML SIG a hook to distribute
3137backwards-compatible updates to the standard xml package.
3138
3139webbrowser - a platform-independent API to launch a web browser.
3140
3141
Guido van Rossume905e952000-09-05 12:42:46 +00003142Changed Modules
3143---------------
3144
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003145array -- new methods for array objects: count, extend, index, pop, and
3146remove
3147
3148binascii -- new functions b2a_hex and a2b_hex that convert between
3149binary data and its hex representation
3150
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003151calendar -- Many new functions that support features including control
3152over which day of the week is the first day, returning strings instead
3153of printing them. Also new symbolic constants for days of week,
3154e.g. MONDAY, ..., SUNDAY.
3155
3156cgi -- FieldStorage objects have a getvalue method that works like a
3157dictionary's get method and returns the value attribute of the object.
3158
3159ConfigParser -- The parser object has new methods has_option,
3160remove_section, remove_option, set, and write. They allow the module
3161to be used for writing config files as well as reading them.
3162
3163ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003164optionally support the RFC 959 REST command.
3165
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003166gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003167
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003168httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3169the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003170
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003171locale -- implement getdefaultlocale for Win32 and Macintosh
3172
3173marshal -- no longer dumps core when marshaling deeply nested or
3174recursive data structures
3175
3176os -- new functions isatty, seteuid, setegid, setreuid, setregid
3177
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003178os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3179support under Unix.
3180
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003181os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003182
3183os.path -- fix semantics of os.path.commonprefix
3184
3185smtplib -- support for sending very long messages
3186
3187socket -- new function getfqdn()
3188
3189readline -- new functions to read, write and truncate history files.
3190The readline section of the library reference manual contains an
3191example.
3192
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003193select -- add interface to poll system call
3194
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003195shutil -- new copyfileobj function
3196
3197SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3198HTTP server.
3199
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003200Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003201
3202urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003203e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003204
3205whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003206
3207
3208Obsolete Modules
3209----------------
3210
3211None. However note that 1.6 made a whole slew of modules obsolete:
3212stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3213poly, zmod, strop, util, whatsound.
3214
3215
3216Changed, New, Obsolete Tools
3217----------------------------
3218
Tim Peters8b092332000-09-05 20:15:25 +00003219None.
Guido van Rossume905e952000-09-05 12:42:46 +00003220
3221
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003222C-level Changes
3223---------------
3224
3225Several cleanup jobs were carried out throughout the source code.
3226
3227All C code was converted to ANSI C; we got rid of all uses of the
3228Py_PROTO() macro, which makes the header files a lot more readable.
3229
3230Most of the portability hacks were moved to a new header file,
3231pyport.h; several other new header files were added and some old
3232header files were removed, in an attempt to create a more rational set
3233of header files. (Few of these ever need to be included explicitly;
3234they are all included by Python.h.)
3235
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003236Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003237and Win64, especially for the new Intel Itanium processor. Mick also
3238added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003239
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003240The C APIs to return an object's size have been update to consistently
3241use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3242previous versions, the abstract interfaces used PyXXX_Length and the
3243concrete interfaces used PyXXX_Size. The old names,
3244e.g. PyObject_Length, are still available for backwards compatibility
3245at the API level, but are deprecated.
3246
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003247The PyOS_CheckStack function has been implemented on Windows by
3248Fredrik Lundh. It prevents Python from failing with a stack overflow
3249on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003250
3251The GC changes resulted in creation of two new slots on object,
3252tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003253the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003254
3255The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003256C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003257
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003258PyErr_Format has been updated to automatically calculate the size of
3259the buffer needed to hold the formatted result string. This change
3260prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003261
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003262New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003263
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003264PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3265that are the same as their non-Ex counterparts except they take an
3266extra flag argument that tells them to close the file when done.
3267
3268XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003269
Tim Peters8b092332000-09-05 20:15:25 +00003270
3271Windows Changes
3272---------------
3273
3274New popen2/popen3/peopen4 in os module (see Changed Modules above).
3275
3276os.popen is much more usable on Windows 95 and 98. See Microsoft
3277Knowledge Base article Q150956. The Win9x workaround described there
3278is implemented by the new w9xpopen.exe helper in the root of your
3279Python installation. Note that Python uses this internally; it is not
3280a standalone program.
3281
3282Administrator privileges are no longer required to install Python
3283on Windows NT or Windows 2000. If you have administrator privileges,
3284Python's registry info will be written under HKEY_LOCAL_MACHINE.
3285Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003286under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003287uses of Python, but will prevent some advanced uses from working
3288(for example, running a Python script as an NT service, or possibly
3289from CGI).
3290
3291[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3292installer; instead, it installs the needed Tcl/Tk files directly in the
3293Python directory. If you already have a Tcl/Tk installation, this
3294wastes some disk space (about 4 Megs) but avoids problems with
3295conflicting Tcl/Tk installations, and makes it much easier for Python
3296to ensure that Tcl/Tk can find all its files.
3297
3298[This was new in 1.6] The Windows installer now installs by default in
3299\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3300
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003301
3302Updates to the changes between 1.5.2 and 1.6
3303--------------------------------------------
3304
3305The 1.6 NEWS file can't be changed after the release is done, so here
3306is some late-breaking news:
3307
3308New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3309and changes to getlocale() and setlocale().
3310
3311The new module is now enabled per default.
3312
3313It is not true that the encodings codecs cannot be used for normal
3314strings: the string.encode() (which is also present on 8-bit strings
3315!) allows using them for 8-bit strings too, e.g. to convert files from
3316cp1252 (Windows) to latin-1 or vice-versa.
3317
3318Japanese codecs are available from Tamito KAJIYAMA:
3319http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3320
3321
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003322======================================================================