blob: 7dc65dc6d4075394aa5798580c60444623efcac4 [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
Tim Petersaf8446f2001-12-21 21:36:50 +000029Extension modules
30
Tim Petersfbf74f22002-03-14 19:06:01 +000031- A security hole ("double free") was found in zlib-1.1.3, a popular
32 third party compression library used by some Python modules. The
33 hole was quickly plugged in zlib-1.1.4, and the Windows build of
34 Python now ships with zlib-1.1.4.
35
Martin v. Löwis29001ff2002-03-01 10:47:37 +000036- pwd and grp return enhanced tuples now, with symbolic field names.
37
Martin v. Löwis99866332002-03-01 10:27:01 +000038- array.array is now a type object. A new format character
39 'u' indicates Py_UNICODE arrays. For those, .tounicode and
40 .fromunicode methods are available. Arrays now support __iadd__
41 and __imul__.
42
Neal Norwitze790eae2002-01-01 21:14:12 +000043- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000044 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
45 is called.
46
Tim Petersaf8446f2001-12-21 21:36:50 +000047Library
48
Martin v. Löwis5c137c22002-03-18 12:44:08 +000049- compileall now supports quiet operation.
50
Martin v. Löwis587c98c2002-03-17 18:37:22 +000051- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
52 connections.
53
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000054- socket module: the SSL support was broken out of the main
55 _socket module C helper and placed into a new _ssl helper
56 which now gets imported by socket.py if available and working.
57
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000058- encodings package: added aliases for all supported IANA character
59 sets
60
Guido van Rossum606fe4e2001-12-28 20:57:14 +000061- ftplib: to safeguard the user's privacy, anonymous login will use
62 "anonymous@" as default password, rather than the real user and host
63 name.
64
Fred Drake36736122002-01-10 13:50:31 +000065- webbrowser: tightened up the command passed to os.system() so that
66 arbitrary shell code can't be executed because a bogus URL was
67 passed in.
68
Tim Peters11bd9942002-02-01 00:52:29 +000069- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000070 gettext.find an optional all argument. Translations will now fallback
71 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000072
Martin v. Löwis9668b932002-01-12 11:27:42 +000073- distutils bdist commands now offer a --skip-build option.
74
Walter Dörwaldb25c2b02002-03-21 10:38:40 +000075- warnings.warn now accepts a Warning instance as first argument.
76
Tim Petersaf8446f2001-12-21 21:36:50 +000077Tools/Demos
78
79Build
80
81C API
82
Neil Schemenauer9d50d132002-03-22 17:06:59 +000083- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
84 functions will be allocated using pymalloc if it is enabled. These
85 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
86 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
87 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
88 PyCore_* family of APIs have been removed.
89
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000090- The "u#" parser marker will now pass through Unicode object as-is
91 without going through the buffer API.
92
Martin v. Löwis7198a522002-01-01 19:59:11 +000093- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
94
Tim Peters10a3bb52001-12-25 19:07:38 +000095- An old #define of ANY as void has been removed from pyport.h. This
96 hasn't been used since Python's pre-ANSI days, and the #define has
97 been marked as obsolete since then. SF bug 495548 says it created
98 conflicts with other packages, so keeping it around wasn't harmless.
99
Tim Petersaf8446f2001-12-21 21:36:50 +0000100- Because Python's magic number scheme broke on January 1st, we decided
101 to stop Python development. Thanks for all the fish!
102
Tim Petersfb05db22002-03-11 00:24:00 +0000103- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000104 scheme to a new one. See Python/import.c for details.
105
Tim Petersaf8446f2001-12-21 21:36:50 +0000106New platforms
107
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000108- GNU/Hurd is now supported.
109
Tim Petersaf8446f2001-12-21 21:36:50 +0000110Tests
111
112Windows
113
Tim Petersfb05db22002-03-11 00:24:00 +0000114- file.truncate([newsize]) now works on Windows for all newsize values.
115 It used to fail if newsize didn't fit in 32 bits, reflecting a
116 limitation of MS _chsize (which is no longer used).
117
Tim Petersab034fa2002-02-01 11:27:43 +0000118- os.waitpid() is now implemented for Windows, and can be used to block
119 until a specified process exits. This is similar to, but not exactly
120 the same as, os.waitpid() on POSIX systems. If you're waiting for
121 a specific process whose pid was obtained from one of the spawn()
122 functions, the same Python os.waitpid() code works across platforms.
123 See the docs for details.
124
Tim Peters11bd9942002-02-01 00:52:29 +0000125- New tempfile.TemporaryFile implementation for Windows: this doesn't
126 need a TemproraryFileWrapper wrapper anymore, and should be immune
127 to a nasty problem: before 2.3, if you got a temp file on Windows, it
128 got wrapped in an object whose close() method first closed the
129 underlying file, then deleted the file. This usually worked fine.
130 However, the spawn family of functions on Windows create (at a low C
131 level) the same set of open files in the spawned process Q as were
132 open in the spawning process P. If a temp file f was among them, then
133 doing f.close() in P first closed P's C-level file handle on f, but Q's
134 C-level file handle on f remained open, so the attempt in P to delete f
135 blew up with a "Permission denied" error (Windows doesn't allow
136 deleting open files). This was surprising, subtle, and difficult to
137 work around.
138
139- The os module now exports all the symbolic constants usable with the
140 low-level os.open() on Windows: the new constants in 2.3 are
141 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
142 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
143 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
144 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
145 (so specify both if you want both; note that neither is useful unless
146 specified with O_CREAT too).
147
Tim Petersaf8446f2001-12-21 21:36:50 +0000148Mac
149
150
Tim Peters909c0912001-12-14 23:16:18 +0000151What's New in Python 2.2 final?
152Release date: 21-Dec-2001
153===============================
154
155Type/class unification and new-style classes
156
Barry Warsaw52acb492001-12-21 20:04:22 +0000157- pickle.py, cPickle: allow pickling instances of new-style classes
158 with a custom metaclass.
159
Tim Peters909c0912001-12-14 23:16:18 +0000160Core and builtins
161
Barry Warsaw52acb492001-12-21 20:04:22 +0000162- weakref proxy object: when comparing, unwrap both arguments if both
163 are proxies.
164
Tim Peters909c0912001-12-14 23:16:18 +0000165Extension modules
166
Barry Warsaw52acb492001-12-21 20:04:22 +0000167- binascii.b2a_base64(): fix a potential buffer overrun when encoding
168 very short strings.
169
170- cPickle: the obscure "fast" mode was suspected of causing stack
171 overflows on the Mac. Hopefully fixed this by setting the recursion
172 limit much smaller. If the limit is too low (it only affects
173 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
174 when compiling cPickle.c (or in pyconfig.h).
175
Tim Peters909c0912001-12-14 23:16:18 +0000176Library
177
Barry Warsaw52acb492001-12-21 20:04:22 +0000178- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
179 close or delete time).
180
181- rfc822.py: fixed a bug where the address '<>' was converted to None
182 instead of an empty string (also fixes the email.Utils module).
183
184- xmlrpclib.py: version 1.0.0; uses precision for doubles.
185
186- test suite: the pickle and cPickle tests were not executing any code
187 when run from the standard regresssion test.
188
Tim Peters909c0912001-12-14 23:16:18 +0000189Tools/Demos
190
191Build
192
193C API
194
195New platforms
196
197Tests
198
199Windows
200
Barry Warsaw52acb492001-12-21 20:04:22 +0000201- distutils package: fixed broken Windows installers (bdist_wininst).
202
203- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
204 instances are deleted at process exit time.
205
206- socket.py: prevent mysterious warnings when socket instances are
207 deleted at process exit time.
208
209- posixmodule.c: fix a Windows crash with stat() of a filename ending
210 in backslash.
211
Tim Peters909c0912001-12-14 23:16:18 +0000212Mac
213
Barry Warsaw52acb492001-12-21 20:04:22 +0000214- The Carbon toolbox modules have been upgraded to Universal Headers
215 3.4, and experimental CoreGraphics and CarbonEvents modules have
216 been added. All only for framework-enabled MacOSX.
217
Tim Peters909c0912001-12-14 23:16:18 +0000218
Tim Peters6272dfd2001-12-13 19:34:00 +0000219What's New in Python 2.2c1?
220Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000221===========================
222
223Type/class unification and new-style classes
224
Barry Warsaw06557452001-12-14 20:47:12 +0000225- Guido's tutorial introduction to the new type/class features has
226 been extensively updated. See
227
228 http://www.python.org/2.2/descrintro.html
229
230 That remains the primary documentation in this area.
231
Guido van Rossum33bab012001-12-05 22:45:48 +0000232- Fixed a leak: instance variables declared with __slots__ were never
233 deleted!
234
Guido van Rossum4b800852001-12-03 00:54:52 +0000235- The "delete attribute" method of descriptor objects is called
236 __delete__, not __del__. In previous releases, it was mistakenly
237 called __del__, which created an unfortunate overloading condition
238 with finalizers. (The "get attribute" and "set attribute" methods
239 are still called __get__ and __set__, respectively.)
240
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000241- Some subtle issues with the super built-in were fixed:
242
243 (a) When super itself is subclassed, its __get__ method would still
244 return an instance of the base class (i.e., of super).
245
246 (b) super(C, C()).__class__ would return C rather than super. This
247 is confusing. To fix this, I decided to change the semantics of
248 super so that it only applies to code attributes, not to data
249 attributes. After all, overriding data attributes is not
250 supported anyway.
251
252 (c) The __get__ method didn't check whether the argument was an
253 instance of the type used in creation of the super instance.
254
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000255- Previously, hash() of an instance of a subclass of a mutable type
256 (list or dictionary) would return some value, rather than raising
257 TypeError. This has been fixed. Also, directly calling
258 dict.__hash__ and list.__hash__ now raises the same TypeError
259 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000260
Guido van Rossumd331cb52001-12-05 19:46:42 +0000261- New-style objects now support deleting their __dict__. This is for
262 all intents and purposes equivalent to assigning a brand new empty
263 dictionary, but saves space if the object is not used further.
264
Tim Petersb3c9af12001-11-17 00:21:57 +0000265Core and builtins
266
Tim Peters3caca232001-12-06 06:23:26 +0000267- -Qnew now works as documented in PEP 238: when -Qnew is passed on
268 the command line, all occurrences of "/" use true division instead
269 of classic division. See the PEP for details. Note that "all"
270 means all instances in library and 3rd-party modules, as well as in
271 your own code. As the PEP says, -Qnew is intended for use only in
272 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000273 Note that test_coercion.py in the standard Python test suite fails
274 under -Qnew; this is expected, and won't be repaired until true
275 division becomes the default (in the meantime, test_coercion is
276 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000277
Fred Drake6c01e252001-12-14 17:08:12 +0000278- complex() now only allows the first argument to be a string
279 argument, and raises TypeError if either the second arg is a string
280 or if the second arg is specified when the first is a string.
281
Tim Petersb3c9af12001-11-17 00:21:57 +0000282Extension modules
283
Martin v. Löwis560da622001-11-24 09:24:51 +0000284- gc.get_referents was renamed to gc.get_referrers.
285
Tim Petersb3c9af12001-11-17 00:21:57 +0000286Library
287
Tim Peters25059d32001-12-07 20:35:43 +0000288- Functions in the os.spawn() family now release the global interpreter
289 lock around calling the platform spawn. They should always have done
290 this, but did not before 2.2c1. Multithreaded programs calling
291 an os.spawn function with P_WAIT will no longer block all Python threads
292 until the spawned program completes. It's possible that some programs
293 relies on blocking, although more likely by accident than by design.
294
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000295- webbrowser defaults to netscape.exe on OS/2 now.
296
Martin v. Löwis652e1912001-11-25 14:50:56 +0000297- Tix.ResizeHandle exposes detach_widget, hide, and show.
298
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000299- The charset alias windows_1252 has been added.
300
Barry Warsaw06557452001-12-14 20:47:12 +0000301- types.StringTypes is a tuple containing the defined string types;
302 usually this will be (str, unicode), but if Python was compiled
303 without Unicode support it will be just (str,).
304
305- The pulldom and minidom modules were synchronized to PyXML.
306
Tim Petersb3c9af12001-11-17 00:21:57 +0000307Tools/Demos
308
Barry Warsaw06557452001-12-14 20:47:12 +0000309- A new script called Tools/scripts/google.py was added, which fires
310 off a search on Google.
311
Tim Petersb3c9af12001-11-17 00:21:57 +0000312Build
313
Barry Warsaw06557452001-12-14 20:47:12 +0000314- Note that release builds of Python should arrange to define the
315 preprocessor symbol NDEBUG on the command line (or equivalent).
316 In the 2.2 pre-release series we tried to define this by magic in
317 Python.h instead, but it proved to cause problems for extension
318 authors. The Unix, Windows and Mac builds now all define NDEBUG in
319 release builds via cmdline (or equivalent) instead. Ports to
320 other platforms should do likewise.
321
Jack Jansen1999ef42001-12-06 21:47:20 +0000322- It is no longer necessary to use --with-suffix when building on a
323 case-insensitive file system (such as Mac OS X HFS+). In the build
324 directory an extension is used, but not in the installed python.
325
Tim Petersb3c9af12001-11-17 00:21:57 +0000326C API
327
Tim Petersf582b822001-12-11 18:51:08 +0000328- New function PyDict_MergeFromSeq2() exposes the builtin dict
329 constructor's logic for updating a dictionary from an iterable object
330 producing key-value pairs.
331
Tim Peterscffed4b2001-11-29 03:26:37 +0000332- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000333 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000334 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
335 dump core in some bad cases. This has been repaired. As a result,
336 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
337 previously went unchallenged.
338
Tim Petersb3c9af12001-11-17 00:21:57 +0000339New platforms
340
341Tests
342
343Windows
344
345Mac
346
Jack Jansenffa260f2001-12-06 21:14:00 +0000347- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
348 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000349
Barry Warsaw06557452001-12-14 20:47:12 +0000350- Changed logic for finding python home in Mac OS X framework Pythons.
351 Now sys.executable points to the executable again, in stead of to
352 the shared library. The latter is used only for locating the python
353 home.
354
355
Tim Peters84362bc2001-10-19 17:55:30 +0000356What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000357Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000358===========================
359
360Type/class unification and new-style classes
361
Guido van Rossum3d27df02001-11-15 20:27:54 +0000362- Multiple inheritance mixing new-style and classic classes in the
363 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000364
365 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000366 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000367
368 The MRO (method resolution order) for each base class is respected
369 according to its kind, but the MRO for the derived class is computed
370 using new-style MRO rules if any base clase is a new-style class.
371 This needs to be documented.
372
Tim Petersa427a2b2001-10-29 22:25:45 +0000373- The new builtin dictionary() constructor, and dictionary type, have
374 been renamed to dict. This reflects a decade of common usage.
375
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000376- dict() now accepts an iterable object producing 2-sequences. For
377 example, dict(d.items()) == d for any dictionary d. The argument,
378 and the elements of the argument, can be any iterable objects.
379
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000380- New-style classes can now have a __del__ method, which is called
381 when the instance is deleted (just like for classic classes).
382
Guido van Rossum12d955c2001-10-26 14:56:06 +0000383- Assignment to object.__dict__ is now possible, for objects that are
384 instances of new-style classes that have a __dict__ (unless the base
385 class forbids it).
386
Guido van Rossumc8e56452001-10-22 00:43:43 +0000387- Methods of built-in types now properly check for keyword arguments
388 (formerly these were silently ignored). The only built-in methods
389 that take keyword arguments are __call__, __init__ and __new__.
390
Guido van Rossum86443212001-10-27 22:28:54 +0000391- The socket function has been converted to a type; see below.
392
Tim Peters84362bc2001-10-19 17:55:30 +0000393Core and builtins
394
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000395- Assignment to __debug__ raises SyntaxError at compile-time. This
396 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000397 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000398
Guido van Rossum12d955c2001-10-26 14:56:06 +0000399- Clarified the error messages for unsupported operands to an operator
400 (like 1 + '').
401
Tim Peters84362bc2001-10-19 17:55:30 +0000402Extension modules
403
Tim Peters5ebfd362001-11-13 23:11:19 +0000404- mmap has a new keyword argument, "access", allowing a uniform way for
405 both Windows and Unix users to create read-only, write-through and
406 copy-on-write memory mappings. This was previously possible only on
407 Unix. A new keyword argument was required to support this in a
408 uniform way because the mmap() signuatures had diverged across
409 platforms. Thanks to Jay T Miller for repairing this!
410
Tim Peters169ded02001-11-03 19:57:21 +0000411- By default, the gc.garbage list now contains only those instances in
412 unreachable cycles that have __del__ methods; in 2.1 it contained all
413 instances in unreachable cycles. "Instances" here has been generalized
414 to include instances of both new-style and old-style classes.
415
Guido van Rossum12d955c2001-10-26 14:56:06 +0000416- The socket module defines a new method for socket objects,
417 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000418 send() until all data has been sent. Also, the socket function has
419 been converted to a subclassable type, like list and tuple (etc.)
420 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000421
422- Various bugfixes to the curses module. There is now a test suite
423 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000424
Guido van Rossum692adf12001-10-30 03:03:03 +0000425- binascii.b2a_base64 no longer places an arbitrary restriction of 57
426 bytes on its input.
427
Tim Peters84362bc2001-10-19 17:55:30 +0000428Library
429
Tim Peters5ebfd362001-11-13 23:11:19 +0000430- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000431 convenience function.
432
Tim Peters75335872001-11-03 19:35:43 +0000433- Symbolic group names in regular expressions must be unique. For
434 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
435 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000436 Python 2.2 detects this error at regexp compilation time;
437 previously, the error went undetected, and results were
438 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
439 pattern.subn() methods have been rewritten in C. Also, an
440 experimental function/method finditer() has been added, which works
441 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000442
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000443- Tix exposes more commands through the classes DirSelectBox,
444 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
445 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
446 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
447
Tim Peters98791af2001-10-23 01:59:54 +0000448- Traceback objects are now scanned by cyclic garbage collection, so
449 cycles created by casual use of sys.exc_info() no longer cause
450 permanent memory leaks (provided garbage collection is enabled).
451
Guido van Rossum49192142001-10-24 20:51:44 +0000452- os.extsep -- a new variable needed by the RISCOS support. It is the
453 separator used by extensions, and is '.' on all platforms except
454 RISCOS, where it is '/'. There is no need to use this variable
455 unless you have a masochistic desire to port your code to RISCOS.
456
Barry Warsaw012852b2001-11-16 16:17:27 +0000457- mimetypes.py has optional support for non-standard, but commonly
458 found types. guess_type() and guess_extension() now accept an
459 optional `strict' flag, defaulting to true, which controls whether
460 recognize non-standard types or not. A few non-standard types we
461 know about have been added. Also, when run as a script, there are
462 new -l and -e options.
463
464- statcache is now deprecated.
465
466- email.Utils.formatdate() now produces the preferred RFC 2822 style
467 dates with numeric timezones (it used to produce obsolete dates
468 hard coded to "GMT" timezone). An optional `localtime' flag is
469 added to produce dates in the local timezone, with daylight savings
470 time properly taken into account.
471
472- In pickle and cPickle, instead of masking errors in load() by
473 transforming them into SystemError, we let the original exception
474 propagate out. Also, implement support for __safe_for_unpickling__
475 in pickle, as it already was supported in cPickle.
476
Tim Peters84362bc2001-10-19 17:55:30 +0000477Tools/Demos
478
479Build
480
Barry Warsaw012852b2001-11-16 16:17:27 +0000481- The dbm module is built using libdb1 if available. The bsddb module
482 is built with libdb3 if available.
483
484- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
485
Tim Peters84362bc2001-10-19 17:55:30 +0000486C API
487
Tim Peters1fc240e2001-10-26 05:06:50 +0000488- New function PySequence_Fast_GET_SIZE() returns the size of a non-
489 NULL result from PySequence_Fast(), more quickly than calling
490 PySequence_Size().
491
Barry Warsaw012852b2001-11-16 16:17:27 +0000492- New argument unpacking function PyArg_UnpackTuple() added.
493
494- New functions PyObject_CallFunctionObjArgs() and
495 PyObject_CallMethodObjArgs() have been added to make it more
496 convenient and efficient to call functions and methods from C.
497
498- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
499 possible that this will propagate errors it didn't before.
500
501- New function PyObject_CheckReadBuffer(), which returns true if its
502 argument supports the single-segment readable buffer interface.
503
Tim Peters84362bc2001-10-19 17:55:30 +0000504New platforms
505
Guido van Rossum86443212001-10-27 22:28:54 +0000506- We've finally confirmed that this release builds on HP-UX 11.00,
507 *with* threads, and passes the test suite.
508
Tim Peters7a33d8b2001-11-05 02:51:07 +0000509- Thanks to a series of patches from Michael Muller, Python may build
510 again under OS/2 Visual Age C++.
511
Guido van Rossum49192142001-10-24 20:51:44 +0000512- Updated RISCOS port by Dietmar Schwertberger.
513
Tim Peters84362bc2001-10-19 17:55:30 +0000514Tests
515
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000516- Added a test script for the curses module. It isn't run automatically;
517 regrtest.py must be run with '-u curses' to enable it.
518
Tim Peters84362bc2001-10-19 17:55:30 +0000519Windows
520
Barry Warsaw012852b2001-11-16 16:17:27 +0000521Mac
522
523- PythonScript has been moved to unsupported and is slated to be
524 removed completely in the next release.
525
526- It should now be possible to build applets that work on both OS9 and
527 OSX.
528
529- The core is now linked with CoreServices not Carbon; as a side
530 result, default 8bit encoding on OSX is now ASCII.
531
532- Python should now build on OSX 10.1.1
533
Tim Peters84362bc2001-10-19 17:55:30 +0000534
Tim Petersabf925f2001-09-28 21:53:42 +0000535What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000536Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000537===========================
538
539Type/class unification and new-style classes
540
Guido van Rossum687ae002001-10-15 22:03:32 +0000541- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000542 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000543 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000544 remains: the __dict__ of a new-style class is a read-only proxy; you
545 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000546 __defined__ attribute of new-style types no longer exists, for lack
547 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000548 future a __cache__ may be resurrected with a similar function, if I
549 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000550
Tim Peters1c9ca872001-10-04 06:43:12 +0000551- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
552 always returned None, even when there was a class docstring).
553
554- doctest now finds and runs docstrings attached to new-style classes,
555 class methods, static methods, and properties.
556
Guido van Rossum9074ef62001-10-16 21:34:49 +0000557Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000558
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000559- A very subtle syntactical pitfall in list comprehensions was fixed.
560 For example: [a+b for a in 'abc', for b in 'def']. The comma in
561 this example is a mistake. Previously, this would silently let 'a'
562 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
563 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
564 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
565 Note that [a for a in <singleton>] is a convoluted way to say
566 [<singleton>] anyway, so it's not like any expressiveness is lost.
567
Guido van Rossum9074ef62001-10-16 21:34:49 +0000568- getattr(obj, name, default) now only catches AttributeError, as
569 documented, rather than returning the default value for all
570 exceptions (which could mask bugs in a __getattr__ hook, for
571 example).
572
Fred Drakecb7a6b52001-10-22 18:41:51 +0000573- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000574 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000575 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000576 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000577
Guido van Rossum1c486092001-10-19 02:05:35 +0000578- unicode(obj) now behaves more like str(obj), accepting arbitrary
579 objects, and calling a __unicode__ method if it exists.
580 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000581 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000582
Barry Warsawf6fb1712001-10-19 05:35:40 +0000583- isinstance() now allows any object as the first argument and a
584 class, a type or something with a __bases__ tuple attribute for the
585 second argument. The second argument may also be a tuple of a
586 class, type, or something with __bases__, in which case isinstance()
587 will return true if the first argument is an instance of any of the
588 things contained in the second argument tuple. E.g.
589
590 isinstance(x, (A, B))
591
592 returns true if x is an instance of A or B.
593
Guido van Rossum9074ef62001-10-16 21:34:49 +0000594Extension modules
595
596- thread.start_new_thread() now returns the thread ID (previously None).
597
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000598- binascii has now two quopri support functions, a2b_qp and b2a_qp.
599
Guido van Rossumc524d952001-10-19 01:31:59 +0000600- readline now supports setting the startup_hook and the
601 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000602
Guido van Rossumc524d952001-10-19 01:31:59 +0000603- os and posix supports chroot(), setgroups() and unsetenv() where
604 available. The stat(), fstat(), statvfs() and fstatvfs() functions
605 now return "pseudo-sequences" -- the various fields can now be
606 accessed as attributes (e.g. os.stat("/").st_mtime) but for
607 backwards compatibility they also behave as a fixed-length sequence.
608 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000609 attributes.
610
611- time: localtime(), gmtime() and strptime() now return a
612 pseudo-sequence similar to the os.stat() return value, with
613 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000614
Guido van Rossum9074ef62001-10-16 21:34:49 +0000615- Decompression objects in the zlib module now accept an optional
616 second parameter to decompress() that specifies the maximum amount
617 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000618
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000619- optional SSL support in the socket module now exports OpenSSL
620 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
621 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000622 automatically seed its PRNG. Also, the keyfile and certfile
623 arguments to socket.ssl() are now optional.
624
625- posixmodule (and by extension, the os module on POSIX platforms) now
626 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000627
Guido van Rossum9074ef62001-10-16 21:34:49 +0000628Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000629
Tim Peters7402f792001-10-02 03:53:41 +0000630- doctest now excludes functions and classes not defined by the module
631 being tested, thanks to Tim Hochberg.
632
Fred Drakecb7a6b52001-10-22 18:41:51 +0000633- HotShot, a new profiler implemented using a C-based callback, has
634 been added. This substantially reduces the overhead of profiling,
635 but it is still quite preliminary. Support modules and
636 documentation will be added in upcoming releases (before 2.2 final).
637
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000638- profile now produces correct output in situations where an exception
639 raised in Python is cleared by C code (e.g. hasattr()). This used
640 to cause wrong output, including spurious claims of recursive
641 functions and attribution of time spent to the wrong function.
642
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000643 The code and documentation for the derived OldProfile and HotProfile
644 profiling classes was removed. The code hasn't worked for years (if
645 you tried to use them, they raised exceptions). OldProfile
646 intended to reproduce the behavior of the profiler Python used more
647 than 7 years ago, and isn't interesting anymore. HotProfile intended
648 to provide a faster profiler (but producing less information), and
649 that's a worthy goal we intend to meet via a different approach (but
650 without losing information).
651
Tim Peterscce092d2001-10-09 05:31:56 +0000652- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000653 a much better system-specific calibration constant. The constant can
654 now be specified in an instance constructor, or as a Profile class or
655 instance variable, instead of by editing profile.py's source code.
656 Calibration must still be done manually (see the docs for the profile
657 module).
658
659 Note that Profile.calibrate() must be overriden by subclasses.
660 Improving the accuracy required exploiting detailed knowledge of
661 profiler internals; the earlier method abstracted away the details
662 and measured a simplified model instead, but consequently computed
663 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000664
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000665- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000666 which indicates whether output is intended for the header 'Q'
667 encoding.
668
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000669- The SocketServer.ThreadingMixIn class now closes the request after
670 finish_request() returns. (Not when it errors out though.)
671
Barry Warsawf6fb1712001-10-19 05:35:40 +0000672- The nntplib module's NNTP.body() method has grown a `file' argument
673 to allow saving the message body to a file.
674
675- The email package has added a class email.Parser.HeaderParser which
676 only parses headers and does not recurse into the message's body.
677 Also, the module/class MIMEAudio has been added for representing
678 audio data (contributed by Anthony Baxter).
679
680- ftplib should be able to handle files > 2GB.
681
682- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
683 ON, and OFF.
684
Fred Drakecb7a6b52001-10-22 18:41:51 +0000685- xml.dom.minidom NodeList objects now support the length attribute
686 and item() method as required by the DOM specifications.
687
Guido van Rossumed554f62001-10-02 23:15:37 +0000688Tools/Demos
689
690- Demo/dns was removed. It no longer serves any purpose; a package
691 derived from it is now maintained by Anthony Baxter, see
692 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000693
Barry Warsawf6fb1712001-10-19 05:35:40 +0000694- The freeze tool has been made more robust, and two new options have
695 been added: -X and -E.
696
Tim Petersabf925f2001-09-28 21:53:42 +0000697Build
698
Barry Warsawf6fb1712001-10-19 05:35:40 +0000699- configure will use CXX in LINKCC if CXX is used to build main() and
700 the system requires to link a C++ main using the C++ compiler.
701
Tim Petersabf925f2001-09-28 21:53:42 +0000702C API
703
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000704- The documentation for the tp_compare slot is updated to require that
705 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
706 not correct. This is not yet enforced but will be enforced in
707 Python 2.3; even later, we may use -2 to indicate errors and +2 for
708 "NotImplemented". Right now, -1 should be used for an error return.
709
Tim Petersd38b1c72001-09-30 05:09:37 +0000710- PyLong_AsLongLong() now accepts int (as well as long) arguments.
711 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
712 as long) arguments.
713
Guido van Rossum3c288632001-10-16 21:13:49 +0000714- PyThread_start_new_thread() now returns a long int giving the thread
715 ID, if one can be calculated; it returns -1 for error, 0 if no
716 thread ID is calculated (this is an incompatible change, but only
717 the thread module used this API). This code has only really been
718 tested on Linux and Windows; other platforms please beware (and
719 report any bugs or strange behavior).
720
Guido van Rossum1c486092001-10-19 02:05:35 +0000721- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
722 input.
723
Tim Petersabf925f2001-09-28 21:53:42 +0000724New platforms
725
726Tests
727
728Windows
729
Tim Peters04cf1d32001-10-09 22:39:40 +0000730- Installer: If you install IDLE, and don't disable file-extension
731 registration, a new "Edit with IDLE" context (right-click) menu entry
732 is created for .py and .pyw files.
733
Tim Peters1ce3cf72001-10-01 17:58:40 +0000734- The signal module now supports SIGBREAK on Windows, thanks to Steven
735 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
736 action remains to call Win32 ExitProcess(). This can be changed via
737 signal.signal(). For example:
738
739 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
740 # (SIGINT) behavior.
741 import signal
742 signal.signal(signal.SIGBREAK,
743 signal.default_int_handler)
744
745 try:
746 while 1:
747 pass
748 except KeyboardInterrupt:
749 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
750 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
751 # program without the possibility for any Python-level cleanup).
752 print "Clean exit"
753
Tim Petersabf925f2001-09-28 21:53:42 +0000754
Tim Petersb07352e2001-09-08 01:25:47 +0000755What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000756Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000757===========================
758
Guido van Rossum808eea72001-09-25 04:15:41 +0000759Type/class unification and new-style classes
760
761- pydoc and inspect are now aware of new-style classes;
762 e.g. help(list) at the interactive prompt now shows proper
763 documentation for all operations on list objects.
764
765- Applications using Jim Fulton's ExtensionClass module can now safely
766 be used with Python 2.2. In particular, Zope 2.4.1 now works with
767 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
768 examples also work again. It is hoped that Gtk and Boost also work
769 with 2.2a4 and beyond. (If you can confirm this, please write
770 webmaster@python.org; if there are still problems, please open a bug
771 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000772
Tim Peters66c1a522001-09-24 21:17:50 +0000773- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
774 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
775 in the constructed property object. fget, fset and fdel weren't
776 discoverable from Python in 2.2a3. __doc__ is new, and allows to
777 associate a docstring with a property.
778
Guido van Rossum808eea72001-09-25 04:15:41 +0000779- Comparison overloading is now more completely implemented. For
780 example, a str subclass instance can properly be compared to a str
781 instance, and it can properly overload comparison. Ditto for most
782 other built-in object types.
783
784- The repr() of new-style classes has changed; instead of <type
785 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
786 *except* for built-in types, which are still rendered as <type
787 'Foo'> (to avoid upsetting existing code that might parse or
788 otherwise rely on repr() of certain type objects).
789
790- The repr() of new-style objects is now always <Foo object at XXX>;
791 previously, it was sometimes <Foo instance at XXX>.
792
793- For new-style classes, what was previously called __getattr__ is now
794 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000795 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000796 one in classic classes is defined which is called only if regular
797 attribute access raises AttributeError; to catch *all* attribute
798 access, you can use __getattribute__ (for new-style classes). If
799 both are defined, __getattribute__ is called first, and if it raises
800 AttributeError, __getattr__ is called.
801
802- The __class__ attribute of new-style objects can be assigned to.
803 The new class must have the same C-level object layout as the old
804 class.
805
806- The builtin file type can be subclassed now. In the usual pattern,
807 "file" is the name of the builtin type, and file() is a new builtin
808 constructor, with the same signature as the builtin open() function.
809 file() is now the preferred way to open a file.
810
811- Previously, __new__ would only see sequential arguments passed to
812 the type in a constructor call; __init__ would see both sequential
813 and keyword arguments. This made no sense whatsoever any more, so
814 now both __new__ and __init__ see all arguments.
815
816- Previously, hash() applied to an instance of a subclass of str or
817 unicode always returned 0. This has been repaired.
818
819- Previously, an operation on an instance of a subclass of an
820 immutable type (int, long, float, complex, tuple, str, unicode),
821 where the subtype didn't override the operation (and so the
822 operation was handled by the builtin type), could return that
823 instance instead a value of the base type. For example, if s was of
824 a str sublass type, s[:] returned s as-is. Now it returns a str
825 with the same value as s.
826
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000827- Provisional support for pickling new-style objects has been added.
828
Guido van Rossum808eea72001-09-25 04:15:41 +0000829Core
830
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000831- file.writelines() now accepts any iterable object producing strings.
832
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000833- PyUnicode_FromEncodedObject() now works very much like
834 PyObject_Str(obj) in that it tries to use __str__/tp_str
835 on the object if the object is not a string or buffer. This
836 makes unicode() behave like str() when applied to non-string/buffer
837 objects.
838
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000839- PyFile_WriteObject now passes Unicode objects to the file's write
840 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000841 of a print statement must support Unicode objects, i.e. they must
842 at least convert them into ASCII strings.
843
Guido van Rossum624c8af2001-09-18 15:21:04 +0000844- Thread scheduling on Solaris should be improved; it is no longer
845 necessary to insert a small sleep at the start of a thread in order
846 to let other runnable threads be scheduled.
847
Tim Petersb07352e2001-09-08 01:25:47 +0000848Library
849
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000850- StringIO.StringIO instances and cStringIO.StringIO instances support
851 read character buffer compatible objects for their .write() methods.
852 These objects are converted to strings and then handled as such
853 by the instances.
854
Barry Warsaw2f600732001-09-24 04:28:10 +0000855- The "email" package has been added. This is basically a port of the
856 mimelib package <http://sf.net/projects/mimelib> with API changes
857 and some implementations updated to use iterators and generators.
858
Tim Peters8a9c2842001-09-22 21:30:22 +0000859- difflib.ndiff() and difflib.Differ.compare() are generators now. This
860 restores the ability of Tools/scripts/ndiff.py to start producing output
861 before the entire comparison is complete.
862
Barry Warsaw58b072d2001-09-22 04:44:21 +0000863- StringIO.StringIO instances and cStringIO.StringIO instances support
864 iteration just like file objects (i.e. their .readline() method is
865 called for each iteration until it returns an empty string).
866
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000867- The codecs module has grown four new helper APIs to access
868 builtin codecs: getencoder(), getdecoder(), getreader(),
869 getwriter().
870
Guido van Rossum624c8af2001-09-18 15:21:04 +0000871- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
872 simplifies writing XML RPC servers.
873
Barry Warsaw647d5e82001-09-28 17:01:02 +0000874- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000875 after interpretation of symbolic links. On non-Unix systems, this
876 is an alias for os.path.abspath().
877
Tim Peters16a77ad2001-09-08 04:00:12 +0000878- operator.indexOf() (PySequence_Index() in the C API) now works with any
879 iterable object.
880
Guido van Rossum624c8af2001-09-18 15:21:04 +0000881- smtplib now supports various authentication and security features of
882 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000883
Guido van Rossum624c8af2001-09-18 15:21:04 +0000884- hmac: a new module implementing keyed hashing for message
885 authentication.
886
887- mimetypes now recognizes more extensions and file types. At the
888 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000889
Guido van Rossum624c8af2001-09-18 15:21:04 +0000890- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000891 Python 2.2 bytecode generation. It has also been promoted from a
892 Tool to a standard library package. (Tools/compiler still exists as
893 a sample driver.)
894
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000895Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000896
Tim Petersb07352e2001-09-08 01:25:47 +0000897Build
898
Guido van Rossum624c8af2001-09-18 15:21:04 +0000899- Large file support (LFS) is now automatic when the platform supports
900 it; no more manual configuration tweaks are needed. On Linux, at
901 least, it's possible to have a system whose C library supports large
902 files but whose kernel doesn't; in this case, large file support is
903 still enabled but doesn't do you any good unless you upgrade your
904 kernel or share your Python executable with another system whose
905 kernel has large file support.
906
907- The configure script now supplies plausible defaults in a
908 cross-compilation environment. This doesn't mean that the supplied
909 values are always correct, or that cross-compilation now works
910 flawlessly -- but it's a first step (and it shuts up most of
911 autoconf's warnings about AC_TRY_RUN).
912
913- The Unix build is now a bit less chatty, courtesy of the parser
914 generator. The build is completely silent (except for errors) when
915 using "make -s", thanks to a -q option to setup.py.
916
Tim Petersb07352e2001-09-08 01:25:47 +0000917C API
918
Guido van Rossum624c8af2001-09-18 15:21:04 +0000919- The "structmember" API now supports some new flag bits to deny read
920 and/or write access to attributes in restricted execution mode.
921
Tim Petersb07352e2001-09-08 01:25:47 +0000922New platforms
923
Guido van Rossum624c8af2001-09-18 15:21:04 +0000924- Compaq's iPAQ handheld, running the "familiar" Linux distribution
925 (http://familiar.handhelds.org).
926
Tim Petersb07352e2001-09-08 01:25:47 +0000927Tests
928
Tim Peters8a9c2842001-09-22 21:30:22 +0000929- The "classic" standard tests, which work by comparing stdout to
930 an expected-output file under Lib/test/output/, no longer stop at
931 the first mismatch. Instead the test is run to completion, and a
932 variant of ndiff-style comparison is used to report all differences.
933 This is much easier to understand than the previous style of reporting.
934
935- The unittest-based standard tests now use regrtest's test_main()
936 convention, instead of running as a side-effect of merely being
937 imported. This allows these tests to be run in more natural and
938 flexible ways as unittests, outside the regrtest framework.
939
940- regrtest.py is much better integrated with unittest and doctest now,
941 especially in regard to reporting errors.
942
Tim Petersb07352e2001-09-08 01:25:47 +0000943Windows
944
Guido van Rossum624c8af2001-09-18 15:21:04 +0000945- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000946 that support it (NTFS under Windows 2000). See "What's New in
947 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000948
Tim Petersb07352e2001-09-08 01:25:47 +0000949
Tim Petersedc99312001-08-22 21:36:50 +0000950What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000951Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000952===========================
953
954Core
955
Tim Peters9fffa3e2001-09-04 05:14:19 +0000956- Conversion of long to float now raises OverflowError if the long is too
957 big to represent as a C double.
958
Tim Peters32f453e2001-09-03 08:35:41 +0000959- The 3-argument builtin pow() no longer allows a third non-None argument
960 if either of the first two arguments is a float, or if both are of
961 integer types and the second argument is negative (in which latter case
962 the arguments are converted to float, so this is really the same
963 restriction).
964
Tim Peters5d2b77c2001-09-03 05:47:38 +0000965- The builtin dir() now returns more information, and sometimes much
966 more, generally naming all attributes of an object, and all attributes
967 reachable from the object via its class, and from its class's base
968 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
969 an empty list. In 2.2a3,
970
971 >>> dir([])
972 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
973 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
974 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
975 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
976 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
977 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
978 'reverse', 'sort']
979
980 dir(module) continues to return only the module's attributes, though.
981
Tim Petersbdee63f2001-09-02 03:40:59 +0000982- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000983 than raising OverflowError. This is a partial implementation of PEP
984 237. You can use -Wdefault::OverflowWarning to enable a warning for
985 this situation, and -Werror::OverflowWarning to revert to the old
986 OverflowError exception.
987
Guido van Rossum61c345f2001-09-04 03:26:15 +0000988- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000989 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000990 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
991 -Qold, meaning the / operator has its classic meaning and no
992 warnings are issued. Using -Qwarn issues a run-time warning about
993 all uses of classic division for int and long arguments; -Qwarnall
994 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000995 (for use with fixdiv.py).
996 [Note: the remainder of this paragraph (preserved below) became
997 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
998 <obsolete>
999 Using -Qnew is questionable; it turns on new division by default, but
1000 only in the __main__ module. You can usefully combine -Qwarn or
1001 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1002 warns about classic division everywhere else.
1003 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001004
Tim Petersbdee63f2001-09-02 03:40:59 +00001005- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001006 long, float, str, unicode, and tuple. (The types complex, list and
1007 dictionary can also be subclassed; this was introduced earlier.)
1008 Note that restrictions apply when subclassing immutable built-in
1009 types: you can only affect the value of the instance by overloading
1010 __new__. You can add mutable attributes, and the subclass instances
1011 will have a __dict__ attribute, but you cannot change the "value"
1012 (as implemented by the base class) of an immutable subclass instance
1013 once it is created.
1014
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001015- The dictionary constructor now takes an optional argument, a
1016 mapping-like object, and initializes the dictionary from its
1017 (key, value) pairs.
1018
Tim Petersbdee63f2001-09-02 03:40:59 +00001019- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001020 "cooperative super calls" in a multiple inheritance setting. For an
1021 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1022
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001023- A new built-in type, property, has been added. This enables the
1024 creation of "properties". These are attributes implemented by
1025 getter and setter functions (or only one of these for read-only or
1026 write-only attributes), without the need to override __getattr__.
1027 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001028
Tim Petersbdee63f2001-09-02 03:40:59 +00001029- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001030 liberalized, to allow leading zeroes. Examples of literals now
1031 legal that were SyntaxErrors before:
1032
1033 00.0 0e3 0100j 07.5 00000000000000000008.
1034
Tim Petersbdee63f2001-09-02 03:40:59 +00001035- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001036 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1037
Tim Petersedc99312001-08-22 21:36:50 +00001038Library
1039
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001040- telnetlib includes symbolic names for the options, and support for
1041 setting an option negotiation callback.
1042
Tim Petersa40c7932001-09-05 22:36:56 +00001043- The new C standard no longer requires that math libraries set errno to
1044 ERANGE on overflow. For platform libraries that exploit this new
1045 freedom, Python's overflow-checking was wholly broken. A new overflow-
1046 checking scheme attempts to repair that, but may not be reliable on all
1047 platforms (C doesn't seem to provide anything both useful and portable
1048 in this area anymore).
1049
Martin v. Löwis44f86962001-09-05 13:44:54 +00001050- Asynchronous timeout actions are available through the new class
1051 threading.Timer.
1052
Tim Peters78526162001-09-05 00:53:45 +00001053- math.log and math.log10 now return sensible results for even huge
1054 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1055
Tim Petersbdee63f2001-09-02 03:40:59 +00001056- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001057 currently held. See the docs for the imp module.
1058
Tim Petersbdee63f2001-09-02 03:40:59 +00001059- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001060 dumps containing ints written on platforms where Python ints are 8 bytes.
1061 When read on a box where Python ints are 4 bytes, such values are
1062 converted to Python longs.
1063
Tim Petersbdee63f2001-09-02 03:40:59 +00001064- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001065 code objects is no longer allowed. This plugs a security hole.
1066
Steve Purcell6091cd62001-09-06 16:05:17 +00001067- unittest.TestResult instances no longer store references to tracebacks
1068 generated by test failures. This prevents unexpected dangling references
1069 to objects that should be garbage collected between tests.
1070
Tim Petersedc99312001-08-22 21:36:50 +00001071Tools
1072
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001073- Tools/scripts/fixdiv.py has been added which can be used to fix
1074 division operators as per PEP 238.
1075
Tim Petersedc99312001-08-22 21:36:50 +00001076Build
1077
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001078- If you are an adventurous person using Mac OS X you may want to look at
1079 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1080 application, which can be used for experimenting with Carbon or Cocoa.
1081 Discussion of this on pythonmac-sig, please.
1082
Tim Peters7eea37e2001-09-04 22:08:56 +00001083C API
1084
1085- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001086
Tim Peters9fffa3e2001-09-04 05:14:19 +00001087- Note that PyLong_AsDouble can fail! This has always been true, but no
1088 callers checked for it. It's more likely to fail now, because overflow
1089 errors are properly detected now. The proper way to check:
1090
1091 double x = PyLong_AsDouble(some_long_object);
1092 if (x == -1.0 && PyErr_Occurred()) {
1093 /* The conversion failed. */
1094 }
1095
Tim Petersbdee63f2001-09-02 03:40:59 +00001096- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001097 compile but will not participate in GC. To upgrade an extension
1098 module:
1099
1100 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001101
Neil Schemenauer4042c692001-08-30 15:38:01 +00001102 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1103 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001104
Neil Schemenauer4042c692001-08-30 15:38:01 +00001105 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1106 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001107
Neil Schemenauer4042c692001-08-30 15:38:01 +00001108 - remove PyGC_HEAD_SIZE from object size calculations
1109
1110 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1111
Tim Petersbdee63f2001-09-02 03:40:59 +00001112- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001113 These can be used safely to construct string objects from a
1114 sprintf-style format string (similar to the format string supported
1115 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001116
Tim Petersedc99312001-08-22 21:36:50 +00001117New platforms
1118
Tim Petersb7da0902001-09-02 23:01:43 +00001119- Stephen Hansen contributed patches sufficient to get a clean compile
1120 under Borland C (Windows), but he reports problems running it and ran
1121 out of time to complete the port. Volunteers? Expect a MemoryError
1122 when importing the types module; this is probably shallow, and
1123 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001124
Tim Petersedc99312001-08-22 21:36:50 +00001125Tests
1126
1127Windows
1128
Tim Peters6e13a562001-09-06 00:32:15 +00001129- Large file support is now enabled on Win32 platforms as well as on
1130 Win64. This means that, for example, you can use f.tell() and f.seek()
1131 to manipulate files larger than 2 gigabytes (provided you have enough
1132 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001133 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1134 filesize limit, and large file support makes no difference there.
1135 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1136 NTFS has no practical limit on file size, and files of any size can be
1137 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001138
Tim Petersbdee63f2001-09-02 03:40:59 +00001139- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001140 points to command.com (patch from Brian Quinlan).
1141
Tim Petersedc99312001-08-22 21:36:50 +00001142
Tim Peters20f51a72001-07-21 02:31:40 +00001143What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001144Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001145===========================
1146
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001147Build
1148
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001149- Tim Peters developed a brand new Windows installer using Wise 8.1,
1150 generously donated to us by Wise Solutions.
1151
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001152- configure supports a new option --enable-unicode, with the values
1153 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1154 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001155
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001156- A new configure option --enable-framework builds a Mac OS X framework,
1157 which "make frameworkinstall" will install. This provides a starting
1158 point for more mac-like functionality, join pythonmac-sig@python.org
1159 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001160
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001161- The NeXT platform is no longer supported.
1162
1163- The `new' module is now statically linked.
1164
Tim Peters0afb6092001-08-15 06:06:44 +00001165Tools
1166
1167- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001168 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001169 the module docstring for details.
1170
Tim Peters20f51a72001-07-21 02:31:40 +00001171Tests
1172
Tim Peters5e824c32001-08-12 22:25:01 +00001173- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001174 platforms, allowing to give clearer test result output. regrtest
1175 also has optional --use/-u switch to run normally disabled tests
1176 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001177
Tim Peters20f51a72001-07-21 02:31:40 +00001178- Several new tests in the standard test suite, with special thanks to
1179 Nick Mathewson.
1180
1181Core
1182
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001183- The floor division operator // has been added as outlined in PEP
1184 238. The / operator still provides classic division (and will until
1185 Python 3.0) unless "from __future__ import division" is included, in
1186 which case the / operator will provide true division. The operator
1187 module provides truediv() and floordiv() functions. Augmented
1188 assignment variants are included, as are the equivalent overloadable
1189 methods and C API methods. See the PEP for a full discussion:
1190 <http://python.sf.net/peps/pep-0238.html>
1191
Tim Peters6cd6a822001-08-17 22:11:27 +00001192- Future statements are now effective in simulated interactive shells
1193 (like IDLE). This should "just work" by magic, but read Michael
1194 Hudson's "Future statements in simulated shells" PEP 264 for full
1195 details: <http://python.sf.net/peps/pep-0264.html>.
1196
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001197- The type/class unification (PEP 252-253) was integrated into the
1198 trunk and is not so tentative any more (the exact specification of
1199 some features is still tentative). A lot of work has done on fixing
1200 bugs and adding robustness and features (performance still has to
1201 come a long way).
1202
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001203- Warnings about a mismatch in the Python API during extension import
1204 now use the Python warning framework (which makes it possible to
1205 write filters for these warnings).
1206
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001207- A function's __dict__ (aka func_dict) will now always be a
1208 dictionary. It used to be possible to delete it or set it to None,
1209 but now both actions raise TypeErrors. It is still legal to set it
1210 to a dictionary object. Getting func.__dict__ before any attributes
1211 have been assigned now returns an empty dictionary instead of None.
1212
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001213- A new command line option, -E, was added which disables the use of
1214 all environment variables, or at least those that are specifically
1215 significant to Python. Usually those have a name starting with
1216 "PYTHON". This was used to fix a problem where the tests fail if
1217 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1218 older distribution.
1219
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001220Library
1221
Tim Peters5e824c32001-08-12 22:25:01 +00001222- New class Differ and new functions ndiff() and restore() in difflib.py.
1223 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001224 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001225
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001226- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1227 value using the minimal quoting required for the value; more
1228 reliable than using xml.sax.saxutils.escape() for attribute values.
1229
1230- Readline completion support for cmd.Cmd was added.
1231
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001232- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1233
1234- Added function threading.BoundedSemaphore()
1235
1236- Added Ka-Ping Yee's cgitb.py module.
1237
1238- The `new' module now exposes the CO_xxx flags.
1239
Martin v. Löwis560da622001-11-24 09:24:51 +00001240- The gc module offers the get_referents function.
1241
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001242New platforms
1243
1244C API
1245
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001246- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1247 which provide a cross-platform implementations for the
1248 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1249 the standard sprintf() and vsprintf() C lib APIs, these versions
1250 apply bounds checking on the used buffer which enhances protection
1251 against buffer overruns.
1252
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001253- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001254 and extensions using different Unicode widths is rendered next to
1255 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001256 will result in an ImportError. Unicode extensions writers must make
1257 sure to check the Unicode width compatibility in their extensions by
1258 using at least one of the mangled Unicode APIs in the extension.
1259
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001260- Two new flags METH_NOARGS and METH_O are available in method definition
1261 tables to simplify implementation of methods with no arguments and a
1262 single untyped argument. Calling such methods is more efficient than
1263 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1264 deprecated.
1265
Tim Petersc1731372001-08-04 08:12:36 +00001266Windows
1267
1268- "import module" now compiles module.pyw if it exists and nothing else
1269 relevant is found.
1270
Tim Peters20f51a72001-07-21 02:31:40 +00001271
Guido van Rossum55a78992001-07-17 17:22:32 +00001272What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001273Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001274===========================
1275
1276Core
Tim Petersa814db52001-05-14 07:05:58 +00001277
Tim Peters6d6c1a32001-08-02 04:15:00 +00001278- TENTATIVELY, a large amount of code implementing much of what's
1279 described in PEP 252 (Making Types Look More Like Classes) and PEP
1280 253 (Subtyping Built-in Types) was added. This will be released
1281 with Python 2.2a1. Documentation will be provided separately
1282 through http://www.python.org/2.2/. The purpose of releasing this
1283 with Python 2.2a1 is to test backwards compatibility. It is
1284 possible, though not likely, that a decision is made not to release
1285 this code as part of 2.2 final, if any serious backwards
1286 incompapatibilities are found during alpha testing that cannot be
1287 repaired.
1288
Guido van Rossum55a78992001-07-17 17:22:32 +00001289- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001290 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001291 more 'yield' statements. See PEP 255. Since this adds a new
1292 keyword to the language, this feature must be enabled by including a
1293 future statement: "from __future__ import generators" (see PEP 236).
1294 Generators will become a standard feature in a future release
1295 (probably 2.3). Without this future statement, 'yield' remains an
1296 ordinary identifier, but a warning is issued each time it is used.
1297 (These warnings currently don't conform to the warnings framework of
1298 PEP 230; we intend to fix this in 2.2a2.)
1299
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001300- The UTF-16 codec was modified to be more RFC compliant. It will now
1301 only remove BOM characters at the start of the string and then
1302 only if running in native mode (UTF-16-LE and -BE won't remove a
1303 leading BMO character).
1304
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001305- Strings now have a new method .decode() to complement the already
1306 existing .encode() method. These two methods provide direct access
1307 to the corresponding decoders and encoders of the registered codecs.
1308
1309 To enhance the usability of the .encode() method, the special
1310 casing of Unicode object return values was dropped (Unicode objects
1311 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001312
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001313 Both methods will now return whatever the codec in charge of the
1314 requested encoding returns as object, e.g. Unicode codecs will
1315 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1316 will return u"äöü"). This enables codec writer to create codecs
1317 for various simple to use conversions.
1318
1319 New codecs were added to demonstrate these new features (the .encode()
1320 and .decode() columns indicate the type of the returned objects):
1321
1322 Name | .encode() | .decode() | Description
1323 ----------------------------------------------------------------------
1324 uu | string | string | UU codec (e.g. for email)
1325 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001326 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001327 zlib | string | string | zlib compression
1328 hex | string | string | 2-byte hex codec
1329 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1330
Mark Hammond2a0af792001-05-14 03:09:36 +00001331- Some operating systems now support the concept of a default Unicode
1332 encoding for file system operations. Notably, Windows supports 'mbcs'
1333 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001334 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001335 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001336
1337 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001338 functions that return filenames (such as os.listdir()) to return Python
1339 string objects pre-encoded using the default file system encoding for
1340 the platform. As this encoding is likely to be different from Python's
1341 default encoding, converting this name to a Unicode object before passing
1342 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001343 would attempt to use its default encoding (generally ASCII) rather than
1344 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001345
Tim Petersa814db52001-05-14 07:05:58 +00001346 In general, this change simply removes surprises when working with
1347 Unicode and the file system, making these operations work as you expect,
1348 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001349 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001350
Tim Peters61dff2b2001-05-08 15:43:37 +00001351- Float (and complex) literals in source code were evaluated to full
1352 precision only when running from a .py file; the same code loaded from a
1353 .pyc (or .pyo) file could suffer numeric differences starting at about the
1354 12th significant decimal digit. For example, on a machine with IEEE-754
1355 floating arithmetic,
1356
1357 x = 9007199254740992.0
1358 print long(x)
1359
1360 printed 9007199254740992 if run directly from .py, but 9007199254740000
1361 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1362 str(float) instead of repr(float) when building code objects. marshal
1363 now uses repr(float) instead, which should reproduce floats to full
1364 machine precision (assuming the platform C float<->string I/O conversion
1365 functions are of good quality).
1366
1367 This may cause floating-point results to change in some cases, and
1368 usually for the better, but may also cause numerically unstable
1369 algorithms to break.
1370
Tim Peters2f228e72001-05-13 00:19:31 +00001371- The implementation of dicts suffers fewer collisions, which has speed
1372 benefits. However, the order in which dict entries appear in dict.keys(),
1373 dict.values() and dict.items() may differ from previous releases for a
1374 given dict. Nothing is defined about this order, so no program should
1375 rely on it. Nevertheless, it's easy to write test cases that rely on the
1376 order by accident, typically because of printing the str() or repr() of a
1377 dict to an "expected results" file. See Lib/test/test_support.py's new
1378 sortdict(dict) function for a simple way to display a dict in sorted
1379 order.
1380
Tim Peters7a3bfc32001-06-12 01:22:22 +00001381- Many other small changes to dicts were made, resulting in faster
1382 operation along the most common code paths.
1383
Guido van Rossum10315822001-05-01 20:54:30 +00001384- Dictionary objects now support the "in" operator: "x in dict" means
1385 the same as dict.has_key(x).
1386
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001387- The update() method of dictionaries now accepts generic mapping
1388 objects. Specifically the argument object must support the .keys()
1389 and __getitem__() methods. This allows you to say, for example,
1390 {}.update(UserDict())
1391
Guido van Rossum10315822001-05-01 20:54:30 +00001392- Iterators were added; this is a generalized way of providing values
1393 to a for loop. See PEP 234. There's a new built-in function iter()
1394 to return an iterator. There's a new protocol to get the next value
1395 from an iterator using the next() method (in Python) or the
1396 tp_iternext slot (in C). There's a new protocol to get iterators
1397 using the __iter__() method (in Python) or the tp_iter slot (in C).
1398 Iterating (i.e. a for loop) over a dictionary generates its keys.
1399 Iterating over a file generates its lines.
1400
Tim Petersf553f892001-05-01 20:45:31 +00001401- The following functions were generalized to work nicely with iterator
1402 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001403 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001404 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1405 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001406 join() method of strings
1407 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001408 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1409 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001410 right-hand side of assignment statements with multiple targets, such as
1411 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001412
Tim Petersd85e1022001-05-11 21:51:48 +00001413- Accessing module attributes is significantly faster (for example,
1414 random.random or os.path or yourPythonModule.yourAttribute).
1415
Tim Peterse63415e2001-05-08 04:38:29 +00001416- Comparing dictionary objects via == and != is faster, and now works even
1417 if the keys and values don't support comparisons other than ==.
1418
Tim Peters95bf9392001-05-10 08:32:44 +00001419- Comparing dictionaries in ways other than == and != is slower: there were
1420 insecurities in the dict comparison implementation that could cause Python
1421 to crash if the element comparison routines for the dict keys and/or
1422 values mutated the dicts. Making the code bulletproof slowed it down.
1423
Tim Peterseb28ef22001-06-02 05:27:19 +00001424- Collisions in dicts are resolved via a new approach, which can help
1425 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001426 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001427 faster now. Thanks to Christian Tismer for pointing out the cause and
1428 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001429
Tim Peters52e155e2001-06-16 05:42:57 +00001430- repr() is much faster for large containers (dict, list, tuple).
1431
1432
Tim Petersa814db52001-05-14 07:05:58 +00001433Library
1434
Fred Drake960fdf92001-07-20 18:38:26 +00001435- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1436 were added to the string module. These a locale-indenpendent
1437 constants, unlike letters, lowercase, and uppercase. These are now
1438 use in appropriate locations in the standard library.
1439
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001440- The flags used in dlopen calls can now be configured using
1441 sys.setdlopenflags and queried using sys.getdlopenflags.
1442
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001443- Fredrik Lundh's xmlrpclib is now a standard library module. This
1444 provides full client-side XML-RPC support. In addition,
1445 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1446 one asyncore-based). Thanks to Eric Raymond for the documentation.
1447
Guido van Rossum643d3912001-07-05 14:46:25 +00001448- The xrange() object is simplified: it no longer supports slicing,
1449 repetition, comparisons, efficient 'in' checking, the tolist()
1450 method, or the start, stop and step attributes. See PEP 260.
1451
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001452- A new function fnmatch.filter to filter lists of file names was added.
1453
Barry Warsawffd674d2001-05-22 16:00:10 +00001454- calendar.py uses month and day names based on the current locale.
1455
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001456- strop is now *really* obsolete (this was announced before with 1.6),
1457 and issues DeprecationWarning when used (except for the four items
1458 that are still imported into string.py).
1459
Tim Petersa814db52001-05-14 07:05:58 +00001460- Cookie.py now sorts key+value pairs by key in output strings.
1461
1462- pprint.isrecursive(object) didn't correctly identify recursive objects.
1463 Now it does.
1464
Tim Peters95b3f782001-05-14 18:39:41 +00001465- pprint functions now much faster for large containers (tuple, list, dict).
1466
Tim Peters7b9542a2001-06-10 23:40:19 +00001467- New 'q' and 'Q' format codes in the struct module, corresponding to C
1468 types "long long" and "unsigned long long" (on Windows, __int64). In
1469 native mode, these can be used only when the platform C compiler supports
1470 these types (when HAVE_LONG_LONG is #define'd by the Python config
1471 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001472 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1473 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001474
Guido van Rossum83213cc2001-06-12 16:48:52 +00001475- The site module installs a new built-in function 'help' that invokes
1476 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1477 it displays a message reminding the user to use 'help()' or
1478 'help(object)'.
1479
Tim Petersa814db52001-05-14 07:05:58 +00001480Tests
1481
1482- New test_mutants.py runs dict comparisons where the key and value
1483 comparison operators mutute the dicts randomly during comparison. This
1484 rapidly causes Python to crash under earlier releases (not for the faint
1485 of heart: it can also cause Win9x to freeze or reboot!).
1486
1487- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001488 pprint.isreadable() return sensible results. Also verifies that simple
1489 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001490
Tim Peters4324aa32001-05-28 22:30:08 +00001491C API
1492
1493- Removed the unused last_is_sticky argument from the internal
1494 _PyTuple_Resize(). If this affects you, you were cheating.
1495
1496
Guido van Rossum55a78992001-07-17 17:22:32 +00001497======================================================================
1498
1499
Guido van Rossumffe13be2001-04-16 18:46:45 +00001500What's New in Python 2.1 (final)?
1501=================================
1502
1503We only changed a few things since the last release candidate, all in
1504Python library code:
1505
1506- A bug in the locale module was fixed that affected locales which
1507 define no grouping for numeric formatting.
1508
1509- A few bugs in the weakref module's implementations of weak
1510 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1511 and the test suite was updated to check for these bugs.
1512
1513- An old bug in the os.path.walk() function (introduced in Python
1514 2.0!) was fixed: a non-existent file would cause an exception
1515 instead of being ignored.
1516
1517- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1518 PyChecker.
1519
1520
Guido van Rossum5b08f132001-04-16 02:05:23 +00001521What's New in Python 2.1c2?
1522===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001523
Guido van Rossum5b08f132001-04-16 02:05:23 +00001524A flurry of small changes, and one showstopper fixed in the nick of
1525time made it necessary to release another release candidate. The list
1526here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001527
Guido van Rossum5b08f132001-04-16 02:05:23 +00001528Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001529
Guido van Rossum5b08f132001-04-16 02:05:23 +00001530- Tim discovered a nasty bug in the dictionary code, caused by
1531 PyDict_Next() calling dict_resize(), and the GC code's use of
1532 PyDict_Next() violating an assumption in dict_items(). This was
1533 fixed with considerable amounts of band-aid, but the net effect is a
1534 saner and more robust implementation.
1535
1536- Made a bunch of symbols static that were accidentally global.
1537
1538Build and Ports
1539
1540- The setup.py script didn't check for a new enough version of zlib
1541 (1.1.3 is needed). Now it does.
1542
1543- Changed "make clean" target to also remove shared libraries.
1544
1545- Added a more general warning about the SGI Irix optimizer to README.
1546
1547Library
1548
1549- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1550 omitted the slash between host and file.html.
1551
1552- The mailbox module's _Mailbox class contained a completely broken
1553 and undocumented seek() method. Ripped it out.
1554
1555- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1556 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1557
1558- Fixed a few last-minute bugs in unittest.
1559
1560Extensions
1561
1562- Reverted the patch to the OpenSSL code in socketmodule.c to support
1563 RAND_status() and the EGD, and the subsequent patch that tried to
1564 fix it for pre-0.9.5 versions; the problem with the patch is that on
1565 some systems it issues a warning whenever socket is imported, and
1566 that's unacceptable.
1567
1568Tests
1569
1570- Fixed the pickle tests to work with "import test.test_pickle".
1571
1572- Tweaked test_locale.py to actually run the test Windows.
1573
1574- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1575 not "wb" (which is not a valid mode at all).
1576
1577- Fix pstats browser crashes. Import readline if it exists to make
1578 the user interface nicer.
1579
1580- Add "import thread" to the top of test modules that import the
1581 threading module (test_asynchat and test_threadedtempfile). This
1582 prevents test failures caused by a broken threading module resulting
1583 from a previously caught failed import.
1584
1585- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1586 needed on some platforms (e.g. Solaris 8) when the tests are run
1587 twice in succession.
1588
1589- Skip rather than fail test_sunaudiodev if no audio device is found.
1590
1591
1592What's New in Python 2.1c1?
1593===========================
1594
1595This list was significantly updated when 2.1c2 was released; the 2.1c1
1596release didn't mention most changes that were actually part of 2.1c1:
1597
1598Legal
1599
1600- Copyright was assigned to the Python Software Foundation (PSF) and a
1601 PSF license (very similar to the CNRI license) was added.
1602
1603- The CNRI copyright notice was updated to include 2001.
1604
1605Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001606
Guido van Rossumc9932722001-04-12 02:31:27 +00001607- After a public outcry, assignment to __debug__ is no longer illegal;
1608 instead, a warning is issued. It will become illegal in 2.2.
1609
Guido van Rossum5b08f132001-04-16 02:05:23 +00001610- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1611 "%#x" now always prepends "0x", even if the value is zero.
1612
1613- Fixed some nits in the bytecode compiler.
1614
1615- Fixed core dumps when calling certain kinds of non-functions.
1616
1617- Fixed various core dumps caused by reference count bugs.
1618
1619Build and Ports
1620
1621- Use INSTALL_SCRIPT to install script files.
1622
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001623- New port: SCO Unixware 7, by Billy G. Allie.
1624
Guido van Rossum5b08f132001-04-16 02:05:23 +00001625- Updated RISCOS port.
1626
1627- Updated BeOS port and notes.
1628
1629- Various other porting problems resolved.
1630
1631Library
1632
1633- The TERMIOS and SOCKET modules are now truly obsolete and
1634 unnecessary. Their symbols are incorporated in the termios and
1635 socket modules.
1636
1637- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1638 better tests for pickling.
1639
1640- threading: make Condition.wait() robust against KeyboardInterrupt.
1641
1642- zipfile: add support to zipfile to support opening an archive
1643 represented by an open file rather than a file name. Fix bug where
1644 the archive was not properly closed. Fixed a bug in this bugfix
1645 where flush() was called for a read-only file.
1646
1647- imputil: added an uninstall() method to the ImportManager.
1648
1649- Canvas: fixed bugs in lower() and tkraise() methods.
1650
1651- SocketServer: API change (added overridable close_request() method)
1652 so that the TCP server can explicitly close the request.
1653
1654- pstats: Eric Raymond added a simple interactive statistics browser,
1655 invoked when the module is run as a script.
1656
1657- locale: fixed a problem in format().
1658
1659- webbrowser: made it work when the BROWSER environment variable has a
1660 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1661 KDE 2. Fixed some other nits.
1662
1663- unittest: changes to allow using a different exception than
1664 AssertionError, and added a few more function aliases. Some other
1665 small changes.
1666
1667- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1668
1669- asynchat: fixed a critical bug in asynchat that slipped through the
1670 2.1b2 release. Fixed another rare bug.
1671
1672- Fix some unqualified except: clauses (always a bad code example).
1673
1674XML
1675
1676- pyexpat: new API get_version_string().
1677
1678- Fixed some minidom bugs.
1679
1680Extensions
1681
1682- Fixed a core dump in _weakref. Removed the weakref.mapping()
1683 function (it adds nothing to the API).
1684
1685- Rationalized the use of header files in the readline module, to make
1686 it compile (albeit with some warnings) with the very recent readline
1687 4.2, without breaking for earlier versions.
1688
1689- Hopefully fixed a buffering problem in linuxaudiodev.
1690
1691- Attempted a fix to make the OpenSSL support in the socket module
1692 work again with pre-0.9.5 versions of OpenSSL.
1693
1694Tests
1695
1696- Added a test case for asynchat and asyncore.
1697
1698- Removed coupling between tests where one test failing could break
1699 another.
1700
1701Tools
1702
1703- Ping added an interactive help browser to pydoc, fixed some nits
1704 in the rest of the pydoc code, and added some features to his
1705 inspect module.
1706
1707- An updated python-mode.el version 4.1 which integrates Ken
1708 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1709 much nicer in XEmacs and Emacs. When stepping through your program
1710 with pdb, in either the shell window or the *Python* window, the
1711 source file and line will be tracked by an arrow. Very cool!
1712
1713- IDLE: syntax warnings in interactive mode are changed into errors.
1714
1715- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001716 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001717
1718- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001719
Barry Warsaw11e89c72001-04-11 20:37:57 +00001720
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001721What's New in Python 2.1 beta 2?
1722================================
1723
Guido van Rossum053ae352001-03-22 14:17:21 +00001724(Unlisted are many fixed bugs, more documentation, etc.)
1725
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001726Core language, builtins, and interpreter
1727
Guido van Rossum053ae352001-03-22 14:17:21 +00001728- The nested scopes work (enabled by "from __future__ import
1729 nested_scopes") is completed; in particular, the future now extends
1730 into code executed through exec, eval() and execfile(), and into the
1731 interactive interpreter.
1732
1733- When calling a base class method (e.g. BaseClass.__init__(self)),
1734 this is now allowed even if self is not strictly spoken a class
1735 instance (e.g. when using metaclasses or the Don Beaudry hook).
1736
1737- Slice objects are now comparable but not hashable; this prevents
1738 dict[:] from being accepted but meaningless.
1739
1740- Complex division is now calculated using less braindead algorithms.
1741 This doesn't change semantics except it's more likely to give useful
1742 results in extreme cases. Complex repr() now uses full precision
1743 like float repr().
1744
1745- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1746
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001747- It is illegal to assign to the name __debug__, which is set when the
1748 interpreter starts. It is effectively a compile-time constant.
1749
1750- A warning will be issued if a global statement for a variable
1751 follows a use or assignment of that variable.
1752
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001753Standard library
1754
Guido van Rossum053ae352001-03-22 14:17:21 +00001755- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1756 inspired by JUnit), is now part of the standard library. You now
1757 have a choice of two testing frameworks: unittest requires you to
1758 write testcases as separate code, doctest gathers them from
1759 docstrings. Both approaches have their advantages and
1760 disadvantages.
1761
1762- A new module Tix was added, which wraps the Tix extension library
1763 for Tk. With that module, it is not necessary to statically link
1764 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1765 require" command. See Demo/tix/.
1766
1767- tzparse.py is now obsolete.
1768
1769- In gzip.py, the seek() and tell() methods are removed -- they were
1770 non-functional anyway, and it's better if callers can test for their
1771 existence with hasattr().
1772
1773Python/C API
1774
1775- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1776 that's already in the dictionary during a PyDict_Next() iteration.
1777 This used to fail occasionally when a dictionary resize operation
1778 could be triggered that would rehash all the keys. All other
1779 modifications to the dictionary are still off-limits during a
1780 PyDict_Next() iteration!
1781
1782- New extended APIs related to passing compiler variables around.
1783
1784- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1785 implement isinstance() and issubclass().
1786
1787- Py_BuildValue() now has a "D" conversion to create a Python complex
1788 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001789
Fred Drake4e262a92001-03-22 18:26:47 +00001790- Extensions types which support weak references must now set the
1791 field allocated for the weak reference machinery to NULL themselves;
1792 this is done to avoid the cost of checking each object for having a
1793 weakly referencable type in PyObject_INIT(), since most types are
1794 not weakly referencable.
1795
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001796- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1797 free variables and cell variables to and from the frame's f_locals.
1798
1799- Variants of several functions defined in pythonrun.h have been added
1800 to support the nested_scopes future statement. The variants all end
1801 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1802 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1803 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001804 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001805
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001806Distutils
1807
1808- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1809 into the release tree.
1810
Tim Peters0e57abf2001-05-02 07:39:38 +00001811- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001812 (an uninstaller, more customization of the installer's display)
1813
1814- from Jack Jansen: added Mac-specific code to generate a dialog for
1815 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001816 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001817 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001818
1819- added 'platforms' and 'keywords' to the set of metadata that can be
1820 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001821
1822- applied patches from Jason Tishler to make the compiler class work with
1823 Cygwin.
1824
1825
Tim Peters2fe289a2001-03-01 22:19:38 +00001826What's New in Python 2.1 beta 1?
1827================================
Tim Petersd66595f2001-02-04 03:09:53 +00001828
1829Core language, builtins, and interpreter
1830
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001831- Following an outcry from the community about the amount of code
1832 broken by the nested scopes feature introduced in 2.1a2, we decided
1833 to make this feature optional, and to wait until Python 2.2 (or at
1834 least 6 months) to make it standard. The option can be enabled on a
1835 per-module basis by adding "from __future__ import nested_scopes" at
1836 the beginning of a module (before any other statements, but after
1837 comments and an optional docstring). See PEP 236 (Back to the
1838 __future__) for a description of the __future__ statement. PEP 227
1839 (Statically Nested Scopes) has been updated to reflect this change,
1840 and to clarify the semantics in a number of endcases.
1841
1842- The nested scopes code, when enabled, has been hardened, and most
1843 bugs and memory leaks in it have been fixed.
1844
1845- Compile-time warnings are now generated for a number of conditions
1846 that will break or change in meaning when nested scopes are enabled:
1847
1848 - Using "from...import *" or "exec" without in-clause in a function
1849 scope that also defines a lambda or nested function with one or
1850 more free (non-local) variables. The presence of the import* or
1851 bare exec makes it impossible for the compiler to determine the
1852 exact set of local variables in the outer scope, which makes it
1853 impossible to determine the bindings for free variables in the
1854 inner scope. To avoid the warning about import *, change it into
1855 an import of explicitly name object, or move the import* statement
1856 to the global scope; to avoid the warning about bare exec, use
1857 exec...in... (a good idea anyway -- there's a possibility that
1858 bare exec will be deprecated in the future).
1859
1860 - Use of a global variable in a nested scope with the same name as a
1861 local variable in a surrounding scope. This will change in
1862 meaning with nested scopes: the name in the inner scope will
1863 reference the variable in the outer scope rather than the global
1864 of the same name. To avoid the warning, either rename the outer
1865 variable, or use a global statement in the inner function.
1866
Neil Schemenauera35c6882001-02-27 04:45:05 +00001867- An optional object allocator has been included. This allocator is
1868 optimized for Python objects and should be faster and use less memory
1869 than the standard system allocator. It is not enabled by default
1870 because of possible thread safety problems. The allocator is only
1871 protected by the Python interpreter lock and it is possible that some
1872 extension modules require a thread safe allocator. The object
1873 allocator can be enabled by providing the "--with-pymalloc" option to
1874 configure.
1875
Tim Petersd66595f2001-02-04 03:09:53 +00001876Standard library
1877
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001878- pyexpat now detects the expat version if expat.h defines it. A
1879 number of additional handlers are provided, which are only available
1880 since expat 1.95. In addition, the methods SetParamEntityParsing and
1881 GetInputContext of Parser objects are available with 1.95.x
1882 only. Parser objects now provide the ordered_attributes and
1883 specified_attributes attributes. A new module expat.model was added,
1884 which offers a number of additional constants if 1.95.x is used.
1885
1886- xml.dom offers the new functions registerDOMImplementation and
1887 getDOMImplementation.
1888
1889- xml.dom.minidom offers a toprettyxml method. A number of DOM
1890 conformance issues have been resolved. In particular, Element now
1891 has an hasAttributes method, and the handling of namespaces was
1892 improved.
1893
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001894- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1895 getting information about live Python code, and pydoc.py, a module
1896 for interactively converting docstrings to HTML or text.
1897 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001898 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001899 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1900 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001901
Tim Peters1eff7962001-03-01 02:31:33 +00001902- New library module difflib.py, primarily packaging the SequenceMatcher
1903 class at the heart of the popular ndiff.py file-comparison tool.
1904
1905- doctest.py (a framework for verifying Python code examples in docstrings)
1906 is now part of the std library.
1907
Tim Petersd66595f2001-02-04 03:09:53 +00001908Windows changes
1909
Guido van Rossume3955a82001-03-02 14:05:59 +00001910- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1911 small GUI that lets you browse the module docstrings using your
1912 default web browser.
1913
Tim Peters1eff7962001-03-01 02:31:33 +00001914- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1915 Platforms) is implemented. See
1916
1917 http://python.sourceforge.net/peps/pep-0235.html
1918
1919 for full details, especially the "Current Lower-Left Semantics" section.
1920 The new Windows import rules are simpler than before:
1921
1922 A. If the PYTHONCASEOK environment variable exists, same as
1923 before: silently accept the first case-insensitive match of any
1924 kind; raise ImportError if none found.
1925
1926 B. Else search sys.path for the first case-sensitive match; raise
1927 ImportError if none found.
1928
1929 The same rules have been implented on other platforms with case-
1930 insensitive but case-preserving filesystems too (including Cygwin, and
1931 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001932
Tim Peters25a9ce32001-02-19 07:06:36 +00001933- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1934 what it's supposed to do (and does do under NT and 2000) via direct
1935 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001936 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001937 all Win9x systems before.
1938
Tim Peters1eff7962001-03-01 02:31:33 +00001939- Build: Subproject _test (effectively) renamed to _testcapi.
1940
Tim Peters2fe289a2001-03-01 22:19:38 +00001941New platforms
1942
1943- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1944 Thanks to Steven Majewski!
1945
1946- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1947 Tishler!
1948
Guido van Rossum9089b272001-03-02 06:49:50 +00001949- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1950 Schwertberger! See RISCOS/README for more information -- it seems
1951 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001952 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001953
Tim Peters25a9ce32001-02-19 07:06:36 +00001954
Tim Petersd7b5e882001-01-25 03:36:26 +00001955What's New in Python 2.1 alpha 2?
1956=================================
Tim Peters40ead762001-01-27 05:35:26 +00001957
Tim Petersd7b5e882001-01-25 03:36:26 +00001958Core language, builtins, and interpreter
1959
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001960- Scopes nest. If a name is used in a function or class, but is not
1961 local, the definition in the nearest enclosing function scope will
1962 be used. One consequence of this change is that lambda statements
1963 could reference variables in the namespaces where the lambda is
1964 defined. In some unusual cases, this change will break code.
1965
1966 In all previous version of Python, names were resolved in exactly
1967 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001968 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001969 function A is defined within a function B, the names bound in B are
1970 not visible in A. The new rules make names bound in B visible in A,
1971 unless A contains a name binding that hides the binding in B.
1972
1973 Section 4.1 of the reference manual describes the new scoping rules
1974 in detail. The test script in Lib/test/test_scope.py demonstrates
1975 some of the effects of the change.
1976
1977 The new rules will cause existing code to break if it defines nested
1978 functions where an outer function has local variables with the same
1979 name as globals or builtins used by the inner function. Example:
1980
1981 def munge(str):
1982 def helper(x):
1983 return str(x)
1984 if type(str) != type(''):
1985 str = helper(str)
1986 return str.strip()
1987
1988 Under the old rules, the name str in helper() is bound to the
1989 builtin function str(). Under the new rules, it will be bound to
1990 the argument named str and an error will occur when helper() is
1991 called.
1992
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001993- The compiler will report a SyntaxError if "from ... import *" occurs
1994 in a function or class scope. The language reference has documented
1995 that this case is illegal, but the compiler never checked for it.
1996 The recent introduction of nested scope makes the meaning of this
1997 form of name binding ambiguous. In a future release, the compiler
1998 may allow this form when there is no possibility of ambiguity.
1999
Tim Peters40ead762001-01-27 05:35:26 +00002000- repr(string) is easier to read, now using hex escapes instead of octal,
2001 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2002
2003 >>> "\texample \r\n" + chr(0) + chr(255)
2004 '\texample \r\n\x00\xff' # in 2.1
2005 '\011example \015\012\000\377' # in 2.0
2006
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002007- Functions are now compared and hashed by identity, not by value, since
2008 the func_code attribute is writable.
2009
Fred Drakefb9d7122001-02-01 20:00:40 +00002010- Weak references (PEP 205) have been added. This involves a few
2011 changes in the core, an extension module (_weakref), and a Python
2012 module (weakref). The weakref module is the public interface. It
2013 includes support for "explicit" weak references, proxy objects, and
2014 mappings with weakly held values.
2015
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002016- A 'continue' statement can now appear in a try block within the body
2017 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002018 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002019
Tim Petersd7b5e882001-01-25 03:36:26 +00002020Standard library
2021
Barry Warsaw30dbd142001-01-31 22:14:01 +00002022- mailbox.py now has a new class, PortableUnixMailbox which is
2023 identical to UnixMailbox but uses a more portable scheme for
2024 determining From_ separators. Also, the constructors for all the
2025 classes in this module have a new optional `factory' argument, which
2026 is a callable used when new message classes must be instantiated by
2027 the next() method.
2028
Tim Petersd7b5e882001-01-25 03:36:26 +00002029- random.py is now self-contained, and offers all the functionality of
2030 the now-deprecated whrandom.py. See the docs for details. random.py
2031 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002032 and restoring the internal state of the generator; and jumpahead(n),
2033 for quickly forcing the internal state to be the same as if n calls to
2034 random() had been made. The latter is particularly useful for multi-
2035 threaded programs, creating one instance of the random.Random() class for
2036 each thread, then using .jumpahead() to force each instance to use a
2037 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002038
Tim Peters0de88fc2001-02-01 04:59:18 +00002039- random.py's seed() function is new. For bit-for-bit compatibility with
2040 prior releases, use the whseed function instead. The new seed function
2041 addresses two problems: (1) The old function couldn't produce more than
2042 about 2**24 distinct internal states; the new one about 2**45 (the best
2043 that can be done in the Wichmann-Hill generator). (2) The old function
2044 sometimes produced identical internal states when passed distinct
2045 integers, and there was no simple way to predict when that would happen;
2046 the new one guarantees to produce distinct internal states for all
2047 arguments in [0, 27814431486576L).
2048
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002049- The socket module now supports raw packets on Linux. The socket
2050 family is AF_PACKET.
2051
Tim Peters9ea17ac2001-02-02 05:57:15 +00002052- test_capi.py is a start at running tests of the Python C API. The tests
2053 are implemented by the new Modules/_testmodule.c.
2054
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002055- A new extension module, _symtable, provides provisional access to the
2056 internal symbol table used by the Python compiler. A higher-level
2057 interface will be added on top of _symtable in a future release.
2058
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002059- Removed the obsolete soundex module.
2060
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002061- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2062 the isSameNode method; NamedNodeMap the get method.
2063
2064- xml.sax.expatreader supports the lexical handler property; it
2065 generates comment, startCDATA, and endCDATA events.
2066
Tim Petersee826f82001-01-31 19:39:44 +00002067Windows changes
2068
2069- Build procedure: the zlib project is built in a different way that
2070 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002071 the zlib binary used. See PCbuild\readme.txt for details. Your old
2072 zlib-related directories can be deleted; you'll need to download fresh
2073 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002074
Tim Peters9ea17ac2001-02-02 05:57:15 +00002075- Build: New subproject _test for the benefit of test_capi.py (see above).
2076
Tim Petersb16c56f2001-02-02 21:24:51 +00002077- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2078 interface to some Python compiler internals).
2079
2080- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002081 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002082
Tim Petersa3a3a032000-11-30 05:22:44 +00002083What's New in Python 2.1 alpha 1?
2084=================================
2085
2086Core language, builtins, and interpreter
2087
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002088- There is a new Unicode companion to the PyObject_Str() API
2089 called PyObject_Unicode(). It behaves in the same way as the
2090 former, but assures that the returned value is an Unicode object
2091 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002092
Guido van Rossumf98eda02001-01-17 15:54:45 +00002093- The comparison operators support "rich comparison overloading" (PEP
2094 207). C extension types can provide a rich comparison function in
2095 the new tp_richcompare slot in the type object. The cmp() function
2096 and the C function PyObject_Compare() first try the new rich
2097 comparison operators before trying the old 3-way comparison. There
2098 is also a new C API PyObject_RichCompare() (which also falls back on
2099 the old 3-way comparison, but does not constrain the outcome of the
2100 rich comparison to a Boolean result).
2101
2102 The rich comparison function takes two objects (at least one of
2103 which is guaranteed to have the type that provided the function) and
2104 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2105 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2106 object, which may be NotImplemented (in which case the tp_compare
2107 slot function is used as a fallback, if defined).
2108
2109 Classes can overload individual comparison operators by defining one
2110 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002111 __ge__. There are no explicit "reflected argument" versions of
2112 these; instead, __lt__ and __gt__ are each other's reflection,
2113 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2114 reflection (similar at the C level). No other implications are
2115 made; in particular, Python does not assume that == is the Boolean
2116 inverse of !=, or that < is the Boolean inverse of >=. This makes
2117 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002118
2119 Classes or types that want to implement (in)equality tests but not
2120 the ordering operators (i.e. unordered types) should implement ==
2121 and !=, and raise an error for the ordering operators.
2122
Guido van Rossuma88479f2001-01-18 14:28:08 +00002123 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002124 Boolean; e.g. a matrix type might want to return a matrix of bits
2125 for A < B, giving elementwise comparisons. Such types should ensure
2126 that any interpretation of their value in a Boolean context raises
2127 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2128 at the C level) to always raise an exception.
2129
Guido van Rossuma88479f2001-01-18 14:28:08 +00002130- Complex numbers use rich comparisons to define == and != but raise
2131 an exception for <, <=, > and >=. Unfortunately, this also means
2132 that cmp() of two complex numbers raises an exception when the two
2133 numbers differ. Since it is not mathematically meaningful to compare
2134 complex numbers except for equality, I hope that this doesn't break
2135 too much code.
2136
Tim Peters3389f192001-02-18 08:48:49 +00002137- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002138 not defined by the language, other than that it's arbitrary but
2139 consistent (see the Reference Manual). An implementation detail changed
2140 in 2.1a1 such that None now compares less than any other object. Code
2141 relying on this new behavior (like code that relied on the previous
2142 behavior) does so at its own risk.
2143
Barry Warsaw573b5412001-01-15 20:43:18 +00002144- Functions and methods now support getting and setting arbitrarily
2145 named attributes (PEP 232). Functions have a new __dict__
2146 (a.k.a. func_dict) which hold the function attributes. Methods get
2147 and set attributes on their underlying im_func. It is a TypeError
2148 to set an attribute on a bound method.
2149
Guido van Rossum051e3352001-01-15 19:11:10 +00002150- The xrange() object implementation has been improved so that
2151 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2152 limitation that in this case len(xrange(sys.maxint)) can't be
2153 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2154 work fine as long as the index i doesn't actually reach 2**31.
2155 (Python uses regular ints for sequence and string indices; fixing
2156 that is much more work.)
2157
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002158- Two changes to from...import:
2159
Guido van Rossumba381232001-02-03 15:06:40 +00002160 1) "from M import X" now works even if (after loading module M)
2161 sys.modules['M'] is not a real module; it's basically a getattr()
2162 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002163
2164 2) "from M import *" now looks for M.__all__ to decide which names to
2165 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2166 filters out names starting with '_' as before. Whether or not
2167 __all__ exists, there's no restriction on the type of M.
2168
Guido van Rossumf61f1662001-01-10 20:13:55 +00002169- File objects have a new method, xreadlines(). This is the fastest
2170 way to iterate over all lines in a file:
2171
2172 for line in file.xreadlines():
2173 ...do something to line...
2174
2175 See the xreadlines module (mentioned below) for how to do this for
2176 other file-like objects.
2177
2178- Even if you don't use file.xreadlines(), you may expect a speedup on
2179 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002180 quite a bit in platform-specific ways: on systems (like Linux) that
2181 support flockfile(), getc_unlocked(), and funlockfile(), those are
2182 used by default. On systems (like Windows) without getc_unlocked(),
2183 a complicated (but still thread-safe) method using fgets() is used by
2184 default.
2185
Tim Petersd52269b2001-01-25 06:23:18 +00002186 You can force use of the fgets() method by #define'ing
2187 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002188 getc_unlocked()).
2189
Tim Petersd52269b2001-01-25 06:23:18 +00002190 You can force fgets() not to be used by #define'ing
2191 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002192 test_bufio.py fails -- and let us know if it does!).
2193
2194- In addition, the fileinput module, while still slower than the other
2195 methods on most platforms, has been sped up too, by using
2196 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002197
2198- Support for run-time warnings has been added, including a new
2199 command line option (-W) to specify the disposition of warnings.
2200 See the description of the warnings module below.
2201
2202- Extensive changes have been made to the coercion code. This mostly
2203 affects extension modules (which can now implement mixed-type
2204 numerical operators without having to use coercion), but
2205 occasionally, in boundary cases the coercion semantics have changed
2206 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002207 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002208 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002209 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002210
Guido van Rossumf98eda02001-01-17 15:54:45 +00002211- In connection with the coercion changes, a new built-in singleton
2212 object, NotImplemented is defined. This can be returned for
2213 operations that wish to indicate they are not implemented for a
2214 particular combination of arguments. From C, this is
2215 Py_NotImplemented.
2216
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002217- The interpreter accepts now bytecode files on the command line even
2218 if they do not have a .pyc or .pyo extension. On Linux, after executing
2219
Martin v. Löwise214baa2001-02-04 22:37:56 +00002220import imp,sys,string
2221magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2222reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2223open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002224
2225 any byte code file can be used as an executable (i.e. as an argument
2226 to execve(2)).
2227
Tim Peters9940b802000-12-01 07:59:35 +00002228- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002229 character. In 1.6 and earlier, they never produced a sign,
2230 and raised an error if the value of the long was too large
2231 to fit in a Python int. In 2.0, they produced a sign if and
2232 only if too large to fit in an int. This was inconsistent
2233 across platforms (because the size of an int varies across
2234 platforms), and inconsistent with hex() and oct(). Example:
2235
2236 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002237 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002238 'ffffffbe' # in 2.0 and before, on 32-bit machines
2239 >>> hex(-0x42L)
2240 '-0x42L' # in all versions of Python
2241
Tim Peters9940b802000-12-01 07:59:35 +00002242 The behavior of %d formats for negative Python longs remains
2243 the same as in 2.0 (although in 1.6 and before, they raised
2244 an error if the long didn't fit in a Python int).
2245
2246 %u formats don't make sense for Python longs, but are allowed
2247 and treated the same as %d in 2.1. In 2.0, a negative long
2248 formatted via %u produced a sign if and only if too large to
2249 fit in an int. In 1.6 and earlier, a negative long formatted
2250 via %u raised an error if it was too big to fit in an int.
2251
Guido van Rossum3661d392000-12-12 22:10:31 +00002252- Dictionary objects have an odd new method, popitem(). This removes
2253 an arbitrary item from the dictionary and returns it (in the form of
2254 a (key, value) pair). This can be useful for algorithms that use a
2255 dictionary as a bag of "to do" items and repeatedly need to pick one
2256 item. Such algorithms normally end up running in quadratic time;
2257 using popitem() they can usually be made to run in linear time.
2258
Tim Peters36cdad12000-12-29 02:06:45 +00002259Standard library
2260
Thomas Woutersfe385252001-01-19 23:16:56 +00002261- In the time module, the time argument to the functions strftime,
2262 localtime, gmtime, asctime and ctime is now optional, defaulting to
2263 the current time (in the local timezone).
2264
Guido van Rossumda91f222001-01-15 16:36:08 +00002265- The ftplib module now defaults to passive mode, which is deemed a
2266 more useful default given that clients are often inside firewalls
2267 these days. Note that this could break if ftplib is used to connect
2268 to a *server* that is inside a firewall, from outside; this is
2269 expected to be a very rare situation. To fix that, you can call
2270 ftp.set_pasv(0).
2271
Martin v. Löwis10a27872001-01-13 09:54:41 +00002272- The module site now treats .pth files not only for path configuration,
2273 but also supports extensions to the initialization code: Lines starting
2274 with import are executed.
2275
Guido van Rossumf61f1662001-01-10 20:13:55 +00002276- There's a new module, warnings, which implements a mechanism for
2277 issuing and filtering warnings. There are some new built-in
2278 exceptions that serve as warning categories, and a new command line
2279 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2280 turns warnings into errors). warnings.warn(message[, category])
2281 issues a warning message; this can also be called from C as
2282 PyErr_Warn(category, message).
2283
2284- A new module xreadlines was added. This exports a single factory
2285 function, xreadlines(). The intention is that this code is the
2286 absolutely fastest way to iterate over all lines in an open
2287 file(-like) object:
2288
2289 import xreadlines
2290 for line in xreadlines.xreadlines(file):
2291 ...do something to line...
2292
2293 This is equivalent to the previous the speed record holder using
2294 file.readlines(sizehint). Note that if file is a real file object
2295 (as opposed to a file-like object), this is equivalent:
2296
2297 for line in file.xreadlines():
2298 ...do something to line...
2299
Tim Peters36cdad12000-12-29 02:06:45 +00002300- The bisect module has new functions bisect_left, insort_left,
2301 bisect_right and insort_right. The old names bisect and insort
2302 are now aliases for bisect_right and insort_right. XXX_right
2303 and XXX_left methods differ in what happens when the new element
2304 compares equal to one or more elements already in the list: the
2305 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002306 right. Code that doesn't care where equal elements end up should
2307 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002308
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002309- The new curses.panel module wraps the panel library that forms part
2310 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2311
Guido van Rossumf61f1662001-01-10 20:13:55 +00002312- The SocketServer module now sets the allow_reuse_address flag by
2313 default in the TCPServer class.
2314
2315- A new function, sys._getframe(), returns the stack frame pointer of
2316 the caller. This is intended only as a building block for
2317 higher-level mechanisms such as string interpolation.
2318
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002319- The pyexpat module supports a number of new handlers, which are
2320 available only in expat 1.2. If invocation of a callback fails, it
2321 will report an additional frame in the traceback. Parser objects
2322 participate now in garbage collection. If expat reports an unknown
2323 encoding, pyexpat will try to use a Python codec; that works only
2324 for single-byte charsets. The parser type objects is exposed as
2325 XMLParserObject.
2326
2327- xml.dom now offers standard definitions for symbolic node type and
2328 exception code constants, and a hierarchy of DOM exceptions. minidom
2329 was adjusted to use them.
2330
2331- The conformance of xml.dom.minidom to the DOM specification was
2332 improved. It detects a number of additional error cases; the
2333 previous/next relationship works even when the tree is modified;
2334 Node supports the normalize() method; NamedNodeMap, DocumentType and
2335 DOMImplementation classes were added; Element supports the
2336 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2337 method.
2338
Guido van Rossumf61f1662001-01-10 20:13:55 +00002339Build issues
2340
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002341- For Unix (and Unix-compatible) builds, configuration and building of
2342 extension modules is now greatly automated. Rather than having to
2343 edit the Modules/Setup file to indicate which modules should be
2344 built and where their include files and libraries are, a
2345 distutils-based setup.py script now takes care of building most
2346 extension modules. All extension modules built this way are built
2347 as shared libraries. Only a few modules that must be linked
2348 statically are still listed in the Setup file; you won't need to
2349 edit their configuration.
2350
2351- Python should now build out of the box on Cygwin. If it doesn't,
2352 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002353
2354- Python now always uses its own (renamed) implementation of getopt()
2355 -- there's too much variation among C library getopt()
2356 implementations.
2357
2358- C++ compilers are better supported; the CXX macro is always set to a
2359 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002360
Tim Petersd92dfe02000-12-12 01:18:41 +00002361Windows changes
2362
2363- select module: By default under Windows, a select() call
2364 can specify no more than 64 sockets. Python now boosts
2365 this Microsoft default to 512. If you need even more than
2366 that, see the MS docs (you'll need to #define FD_SETSIZE
2367 and recompile Python from source).
2368
Guido van Rossumf61f1662001-01-10 20:13:55 +00002369- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2370 subdirectory is no more!
2371
Tim Petersa3a3a032000-11-30 05:22:44 +00002372
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002373What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002374=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002375
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002376Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002377changes are in the file HISTORY. If you are making the jump directly
2378from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2379HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002380
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002381Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2382the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2383http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002384
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002385--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002386
2387======================================================================
2388
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002389What's new in 2.0 (since release candidate 1)?
2390==============================================
2391
2392Standard library
2393
2394- The copy_reg module was modified to clarify its intended use: to
2395 register pickle support for extension types, not for classes.
2396 pickle() will raise a TypeError if it is passed a class.
2397
2398- Fixed a bug in gettext's "normalize and expand" code that prevented
2399 it from finding an existing .mo file.
2400
2401- Restored support for HTTP/0.9 servers in httplib.
2402
Tim Peters989b7b92000-10-16 20:24:53 +00002403- The math module was changed to stop raising OverflowError in case of
2404 underflow, and return 0 instead in underflow cases. Whether Python
2405 used to raise OverflowError in case of underflow was platform-
2406 dependent (it did when the platform math library set errno to ERANGE
2407 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002408
2409- Fixed a bug in StringIO that occurred when the file position was not
2410 at the end of the file and write() was called with enough data to
2411 extend past the end of the file.
2412
2413- Fixed a bug that caused Tkinter error messages to get lost on
2414 Windows. The bug was fixed by replacing direct use of
2415 interp->result with Tcl_GetStringResult(interp).
2416
2417- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2418 redirect response.
2419
2420- Several changes were made to distutils: Some debugging code was
2421 removed from util. Fixed the installer used when an external zip
2422 program (like WinZip) is not found; the source code for this
2423 installer is in Misc/distutils. check_lib() was modified to behave
2424 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2425 test for whether installed modules are on sys.path was changed to
2426 use both normcase() and normpath().
2427
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002428- Several minor bugs were fixed in the xml package (the minidom,
2429 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002430
2431- The regression test driver (regrtest.py) behavior when invoked with
2432 -l changed: It now reports a count of objects that are recognized as
2433 garbage but not freed by the garbage collector.
2434
Tim Peters989b7b92000-10-16 20:24:53 +00002435- The regression test for the math module was changed to test
2436 exceptional behavior when the test is run in verbose mode. Python
2437 cannot yet guarantee consistent exception behavior across platforms,
2438 so the exception part of test_math is run only in verbose mode, and
2439 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002440
2441Internals
2442
2443- PyOS_CheckStack() has been disabled on Win64, where it caused
2444 test_sre to fail.
2445
2446Build issues
2447
2448- Changed compiler flags, so that gcc is always invoked with -Wall and
2449 -Wstrict-prototypes. Users compiling Python with GCC should see
2450 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002451 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002452 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002453
Tim Petersa3a3a032000-11-30 05:22:44 +00002454- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002455
2456Tools and other miscellany
2457
2458- The compiler in Tools/compiler was updated to support the new
2459 language features introduced in 2.0: extended print statement, list
2460 comprehensions, and augmented assignments. The new compiler should
2461 also be backwards compatible with Python 1.5.2; the compiler will
2462 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002463 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002464
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002465What's new in 2.0 release candidate 1 (since beta 2)?
2466=====================================================
2467
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002468What is release candidate 1?
2469
2470We believe that release candidate 1 will fix all known bugs that we
2471intend to fix for the 2.0 final release. This release should be a bit
2472more stable than the previous betas. We would like to see even more
2473widespread testing before the final release, so we are producing this
2474release candidate. The final release will be exactly the same unless
2475any show-stopping (or brown bag) bugs are found by testers of the
2476release candidate.
2477
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002478All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002479to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002480
2481Core language, builtins, and interpreter
2482
2483- A bug that caused crashes when __coerce__ was used with augmented
2484 assignment, e.g. +=, was fixed.
2485
2486- Raise ZeroDivisionError when raising zero to a negative number,
2487 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2488 power operator and the result of math.pow(0.0, -2.0) will vary by
2489 platform. On Linux, it raises a ValueError.
2490
2491- A bug in Unicode string interpolation was fixed that occasionally
2492 caused errors with formats including "%%". For example, the
2493 following expression "%% %s" % u"abc" no longer raises a TypeError.
2494
2495- Compilation of deeply nested expressions raises MemoryError instead
2496 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2497
2498- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2499 rendering them useless. They are now written in binary mode again.
2500
2501Standard library
2502
2503- Keyword arguments are now accepted for most pattern and match object
2504 methods in SRE, the standard regular expression engine.
2505
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002506- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002507 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002508
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002509- Several bugs in the Unicode handling and error handling in _tkinter
2510 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002511
2512- Fix memory management errors in Merge() and Tkapp_Call() routines.
2513
2514- Several changes were made to cStringIO to make it compatible with
2515 the file-like object interface and with StringIO. If operations are
2516 performed on a closed object, an exception is raised. The truncate
2517 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002518 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002519
2520- There were many changes made to the linuxaudiodev module and its
2521 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002522 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002523
2524 Note that this module is named poorly, because it should work
2525 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002526 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002527
2528 The module now raises exceptions when errors occur instead of
2529 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2530 audio) and defines a getptr() method that calls the
2531 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2532
2533- The library_version attribute, introduced in an earlier beta, was
2534 removed because it can not be supported with early versions of the C
2535 readline library, which provides no way to determine the version at
2536 compile-time.
2537
2538- The binascii module is now enabled on Win64.
2539
Tim Peters46446d62000-10-09 21:19:31 +00002540- tokenize.py no longer suffers "recursion depth" errors when parsing
2541 programs with very long string literals.
2542
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002543Internals
2544
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002545- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002546 which is called when the interpreter starts up to determine where
2547 the standard library is installed. These vulnerabilities affect all
2548 previous versions of Python and can be exploited by setting very
2549 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2550 setuid Python script, although use of the wrapper in
2551 Misc/setuid-prog.c will eliminate the vulnerability.
2552
2553- Fixed garbage collection bugs in instance creation that were
2554 triggered when errors occurred during initialization. The solution,
2555 applied in cPickle and in PyInstance_New(), is to call
2556 PyObject_GC_Init() after the initialization of the object's
2557 container attributes is complete.
2558
2559- pyexpat adds definitions of PyModule_AddStringConstant and
2560 PyModule_AddObject if the Python version is less than 2.0, which
2561 provides compatibility with PyXML on Python 1.5.2.
2562
2563- If the platform has a bogus definition for LONG_BIT (the number of
2564 bits in a long), an error will be reported at compile time.
2565
2566- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2567 collection crashes and possibly other, unreported crashes.
2568
2569- Fixed a memory leak in _PyUnicode_Fini().
2570
2571Build issues
2572
2573- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002574 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002575 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002576
2577- The mmap.PAGESIZE constant is now initialized using sysconf when
2578 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2579
2580- The md5 file should now compile on all platforms.
2581
2582- The select module now compiles on platforms that do not define
2583 POLLRDNORM and related constants.
2584
2585- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002586 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002587
Jeremy Hylton10921202000-10-09 18:34:12 +00002588- BeOS: A number of changes were made to the build and installation
2589 process. ar-fake now operates on a directory of object files.
2590 dl_export.h is gone, and its macros now appear on the mwcc command
2591 line during build on PPC BeOS.
2592
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002593- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002594 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002595
2596- Cygwin: Support for shared libraries, Tkinter, and sockets.
2597
2598- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2599
2600Tools and other miscellany
2601
2602- Removed debugging prints from main used with freeze.
2603
Tim Peters46446d62000-10-09 21:19:31 +00002604- IDLE auto-indent no longer crashes when it encounters Unicode
2605 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002606
2607What's new in 2.0 beta 2 (since beta 1)?
2608========================================
2609
2610Core language, builtins, and interpreter
2611
Tim Peters482c0212000-09-26 06:33:09 +00002612- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002613 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002614
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002615- Add -h and -V command line options to print the usage message and
2616 Python version number and exit immediately.
2617
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002618- eval() and exec accept Unicode objects as code parameters.
2619
2620- getattr() and setattr() now also accept Unicode objects for the
2621 attribute name, which are converted to strings using the default
2622 encoding before lookup.
2623
2624- Multiplication on string and Unicode now does proper bounds
2625 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2626 string is too long."
2627
2628- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002629 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002630
Jeremy Hylton1b618592000-09-26 05:32:36 +00002631
2632Standard library and extensions
2633
Guido van Rossum5b08f132001-04-16 02:05:23 +00002634- socket module: the OpenSSL code now adds support for RAND_status()
2635 and EGD (Entropy Gathering Device).
2636
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002637- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002638 argument checking; it still takes no arguments.
2639
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002640- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002641
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002642- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002643
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002644- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002645
2646- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002647 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002648
2649- copy: Copy Unicode objects atomically.
2650
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002651- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002652
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002653- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002654
Fred Drake67233bc2000-09-26 16:40:27 +00002655- dbm: Add get() and setdefault() methods to dbm object. Add constant
2656 `library' to module that names the library used. Added doc strings
2657 and method names to error messages. Uses configure to determine
2658 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2659 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002660
2661- distutils: Update to version 0.9.3.
2662
2663- dl: Add several dl.RTLD_ constants.
2664
2665- fpectl: Now supported on FreeBSD.
2666
2667- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2668 found by the collector will be saved in gc.garbage. This is useful
2669 for debugging a program that creates reference cycles.
2670
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002671- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002672 of HTTP class. Do not close socket on zero-length response. Do not
2673 crash when server sends invalid content-length header.
2674
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002675- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002676
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002677- marshal: When reading a short, sign-extend on platforms where shorts
2678 are bigger than 16 bits. When reading a long, repair the unportable
2679 sign extension that was being done for 64-bit machines. (It assumed
2680 that signed right shift sign-extends.)
2681
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002682- operator: Add contains(), invert(), __invert__() as aliases for
2683 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002684
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002685- os: Add support for popen2() and popen3() on all platforms where
2686 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002687
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002688- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002689 clicking on a file in Explorer (or passing the file name to the
2690 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002691
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002692- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002693 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002694
2695- pickle: Now raises ValueError when an invalid pickle that contains
2696 a non-string repr where a string repr was expected. This behavior
2697 matches cPickle.
2698
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002699- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002700
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002701- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002702
2703- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002704 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002705 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002706
2707- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002708 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002709
2710- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002711 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002712 few cycles during startup since the first call to
2713 setdefaultencoding() will initialize the codec registry and the
2714 encodings package.
2715
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002716- socket: Support for size hint in readlines() method of object returned
2717 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002719- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002720 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721 is followed by whitespace.
2722
Tim Petersa3a3a032000-11-30 05:22:44 +00002723- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002724
2725- struct: Check ranges for bytes and shorts.
2726
2727- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002728 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002729
2730- Tkinter: Image objects are now guaranteed to have unique ids. Set
2731 event.delta to zero if Tk version doesn't support mousewheel.
2732 Removed some debugging prints.
2733
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002734- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002735
Fred Drake67233bc2000-09-26 16:40:27 +00002736- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002737 which works around a bug in Norton AntiVirus 2000 that leads directly
2738 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002739
2740- xml: New version detection code allows PyXML to override standard
2741 XML package if PyXML version is greater than 0.6.1.
2742
Fred Drake64bb3802000-09-26 16:21:35 +00002743- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2744 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2745 tree only for nodes which are sufficiently interesting to a specific
2746 application. Does not provide the HTML-specific extensions. Still
2747 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002748
Fred Drake64bb3802000-09-26 16:21:35 +00002749- xml.sax: SAX 2 support for Python, including all the handler
2750 interfaces needed to process XML 1.0 compliant XML. Some
2751 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002752
Fred Drake64bb3802000-09-26 16:21:35 +00002753- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2754 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002755
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002756
Jeremy Hylton1b618592000-09-26 05:32:36 +00002757C API
2758
2759- Add three new convenience functions for module initialization --
2760 PyModule_AddObject(), PyModule_AddIntConstant(), and
2761 PyModule_AddStringConstant().
2762
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002763- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002764 removed and add #error to Python.h if NULL isn't defined after
2765 #include of stdio.h.
2766
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002767- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002768 backwards compatibility (at the source level) with old extensions.
2769
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002770- A wrapper API was added for signal() and sigaction(). Instead of
2771 either function, always use PyOS_getsig() to get a signal handler
2772 and PyOS_setsig() to set one. A new convenience typedef
2773 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002774
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002775- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002776 internal data buffer and size of a string object -- or the default
2777 encoded version of a Unicode object.
2778
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002779- PyString_Size() and PyString_AsString() accept Unicode objects.
2780
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002781- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002782 exists). INT_MAX and LONG_MAX will always be defined, even if
2783 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002784
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002785- PyFloat_FromString takes a second argument, pend, that was
2786 effectively useless. It is now officially useless but preserved for
2787 backwards compatibility. If the pend argument is not NULL, *pend is
2788 set to NULL.
2789
2790- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2791 for the attribute name. See note on getattr() above.
2792
2793- A few bug fixes to argument processing for Unicode.
2794 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2795 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2796 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002797 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002798
2799- Py_BuildValue accepts B format (for bgen-generated code).
2800
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002801
Jeremy Hylton1b618592000-09-26 05:32:36 +00002802Internals
2803
2804- On Unix, fix code for finding Python installation directory so that
2805 it works when argv[0] is a relative path.
2806
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002807- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002808 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002809 rather than by generating a copy of the object.
2810
Tim Peters482c0212000-09-26 06:33:09 +00002811- Several of the internal Unicode tables are much smaller now, and
2812 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002813
Jeremy Hylton97693b02000-09-26 17:42:51 +00002814- In the garbage collector: Fixed bug in collection of tuples. Fixed
2815 bug that caused some instances to be removed from the container set
2816 while they were still live. Fixed parsing in gc.set_debug() for
2817 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002818
2819- Fixed refcount problem in instance deallocation that only occurred
2820 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2821
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002822- On Windows, getpythonregpath is now protected against null data in
2823 registry key.
2824
2825- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002826 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002827
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002828
Jeremy Hylton1b618592000-09-26 05:32:36 +00002829Build and platform-specific issues
2830
2831- Better support of GNU Pth via --with-pth configure option.
2832
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002833- Python/C API now properly exposed to dynamically-loaded extension
2834 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002835
2836- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2837 Don't define MS_SYNC to be zero when it is undefined. Added missing
2838 prototypes in posixmodule.c.
2839
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002840- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002841 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002842
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002843- Fix largefile support on older NetBSD systems and OpenBSD by adding
2844 define for TELL64.
2845
2846
2847Tools and other miscellany
2848
2849- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2850
2851- freeze: The modulefinder now works with 2.0 opcodes.
2852
Tim Petersa3a3a032000-11-30 05:22:44 +00002853- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002854 Move hackery of sys.argv until after the Tk instance has been
2855 created, which allows the application-specific Tkinter
2856 initialization to be executed if present; also pass an explicit
2857 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002858
Jeremy Hylton1b618592000-09-26 05:32:36 +00002859
2860What's new in 2.0 beta 1?
2861=========================
2862
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002863Source Incompatibilities
2864------------------------
2865
2866None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2867such as single-argument append(), connect() and bind(), and changes to
2868str(long) and repr(float).
2869
2870
2871Binary Incompatibilities
2872------------------------
2873
2874- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2875with Python 2.0; these extensions will have to be rebuilt for Python
28762.0.
2877
2878- On Windows, attempting to import a third party extension built for
2879Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2880can do about this. Check your PYTHONPATH environment variable!
2881
2882- Python bytecode files (*.pyc and *.pyo) are not compatible between
2883releases.
2884
2885
2886Overview of Changes Since 1.6
2887-----------------------------
2888
2889There are many new modules (including brand new XML support through
2890the xml package, and i18n support through the gettext module); a list
2891of all new modules is included below. Lots of bugs have been fixed.
2892
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002893The process for making major new changes to the language has changed
2894since Python 1.6. Enhancements must now be documented by a Python
2895Enhancement Proposal (PEP) before they can be accepted.
2896
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002897There are several important syntax enhancements, described in more
2898detail below:
2899
2900 - Augmented assignment, e.g. x += 1
2901
2902 - List comprehensions, e.g. [x**2 for x in range(10)]
2903
2904 - Extended import statement, e.g. import Module as Name
2905
2906 - Extended print statement, e.g. print >> file, "Hello"
2907
2908Other important changes:
2909
2910 - Optional collection of cyclical garbage
2911
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002912Python Enhancement Proposal (PEP)
2913---------------------------------
2914
2915PEP stands for Python Enhancement Proposal. A PEP is a design
2916document providing information to the Python community, or describing
2917a new feature for Python. The PEP should provide a concise technical
2918specification of the feature and a rationale for the feature.
2919
2920We intend PEPs to be the primary mechanisms for proposing new
2921features, for collecting community input on an issue, and for
2922documenting the design decisions that have gone into Python. The PEP
2923author is responsible for building consensus within the community and
2924documenting dissenting opinions.
2925
2926The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002927
2928Augmented Assignment
2929--------------------
2930
2931This must have been the most-requested feature of the past years!
2932Eleven new assignment operators were added:
2933
Guido van Rossume905e952000-09-05 12:42:46 +00002934 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002935
2936For example,
2937
2938 A += B
2939
2940is similar to
2941
2942 A = A + B
2943
2944except that A is evaluated only once (relevant when A is something
2945like dict[index].attr).
2946
2947However, if A is a mutable object, A may be modified in place. Thus,
2948if A is a number or a string, A += B has the same effect as A = A+B
2949(except A is only evaluated once); but if a is a list, A += B has the
2950same effect as A.extend(B)!
2951
2952Classes and built-in object types can override the new operators in
2953order to implement the in-place behavior; the not-in-place behavior is
2954used automatically as a fallback when an object doesn't implement the
2955in-place behavior. For classes, the method name is derived from the
2956method name for the corresponding not-in-place operator by inserting
2957an 'i' in front of the name, e.g. __iadd__ implements in-place
2958__add__.
2959
2960Augmented assignment was implemented by Thomas Wouters.
2961
2962
2963List Comprehensions
2964-------------------
2965
2966This is a flexible new notation for lists whose elements are computed
2967from another list (or lists). The simplest form is:
2968
2969 [<expression> for <variable> in <sequence>]
2970
Guido van Rossum56db0952000-09-06 23:34:25 +00002971For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002972This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002973
2974You can also add a condition:
2975
2976 [<expression> for <variable> in <sequence> if <condition>]
2977
2978For example, [w for w in words if w == w.lower()] would yield the list
2979of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002980than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002981
2982You can also have nested for loops and more than one 'if' clause. For
2983example, here's a function that flattens a sequence of sequences::
2984
2985 def flatten(seq):
2986 return [x for subseq in seq for x in subseq]
2987
2988 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2989
2990This prints
2991
2992 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2993
2994List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002995Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002996
2997
2998Extended Import Statement
2999-------------------------
3000
3001Many people have asked for a way to import a module under a different
3002name. This can be accomplished like this:
3003
3004 import foo
3005 bar = foo
3006 del foo
3007
3008but this common idiom gets old quickly. A simple extension of the
3009import statement now allows this to be written as follows:
3010
3011 import foo as bar
3012
3013There's also a variant for 'from ... import':
3014
3015 from foo import bar as spam
3016
3017This also works with packages; e.g. you can write this:
3018
3019 import test.regrtest as regrtest
3020
3021Note that 'as' is not a new keyword -- it is recognized only in this
3022context (this is only possible because the syntax for the import
3023statement doesn't involve expressions).
3024
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003025Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003026
3027
3028Extended Print Statement
3029------------------------
3030
3031Easily the most controversial new feature, this extension to the print
3032statement adds an option to make the output go to a different file
3033than the default sys.stdout.
3034
3035For example, to write an error message to sys.stderr, you can now
3036write:
3037
3038 print >> sys.stderr, "Error: bad dog!"
3039
3040As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003041evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003042
3043 print >> None, "Hello world"
3044
3045is equivalent to
3046
3047 print "Hello world"
3048
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003049Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003050
3051
3052Optional Collection of Cyclical Garbage
3053---------------------------------------
3054
3055Python is now equipped with a garbage collector that can hunt down
3056cyclical references between Python objects. It's no replacement for
3057reference counting; in fact, it depends on the reference counts being
3058correct, and decides that a set of objects belong to a cycle if all
3059their reference counts can be accounted for from their references to
3060each other. This devious scheme was first proposed by Eric Tiedemann,
3061and brought to implementation by Neil Schemenauer.
3062
3063There's a module "gc" that lets you control some parameters of the
3064garbage collection. There's also an option to the configure script
3065that lets you enable or disable the garbage collection. In 2.0b1,
3066it's on by default, so that we (hopefully) can collect decent user
3067experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003068performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003069off by default in the final 2.0 release.
3070
3071
3072Smaller Changes
3073---------------
3074
3075A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3076map(None, seq1, seq2, ...) when the sequences have the same length;
3077i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3078the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003079zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003080
3081sys.version_info is a tuple (major, minor, micro, level, serial).
3082
3083Dictionaries have an odd new method, setdefault(key, default).
3084dict.setdefault(key, default) returns dict[key] if it exists; if not,
3085it sets dict[key] to default and returns that value. Thus:
3086
3087 dict.setdefault(key, []).append(item)
3088
3089does the same work as this common idiom:
3090
3091 if not dict.has_key(key):
3092 dict[key] = []
3093 dict[key].append(item)
3094
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003095There are two new variants of SyntaxError that are raised for
3096indentation-related errors: IndentationError and TabError.
3097
3098Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3099escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003100
3101The limits on the size of expressions and file in Python source code
3102have been raised from 2**16 to 2**32. Previous versions of Python
3103were limited because the maximum argument size the Python VM accepted
3104was 2**16. This limited the size of object constructor expressions,
3105e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3106limit was raised thanks to a patch by Charles Waldman that effectively
3107fixes the problem. It is now much more likely that you will be
3108limited by available memory than by an arbitrary limit in Python.
3109
3110The interpreter's maximum recursion depth can be modified by Python
3111programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3112limit is the maximum number of recursive calls that can be made by
3113Python code. The limit exists to prevent infinite recursion from
3114overflowing the C stack and causing a core dump. The default value is
31151000. The maximum safe value for a particular platform can be found
3116by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003117
3118New Modules and Packages
3119------------------------
3120
3121atexit - for registering functions to be called when Python exits.
3122
3123imputil - Greg Stein's alternative API for writing custom import
3124hooks.
3125
3126pyexpat - an interface to the Expat XML parser, contributed by Paul
3127Prescod.
3128
3129xml - a new package with XML support code organized (so far) in three
3130subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3131would fill a volume. There's a special feature whereby a
3132user-installed package named _xmlplus overrides the standard
3133xmlpackage; this is intended to give the XML SIG a hook to distribute
3134backwards-compatible updates to the standard xml package.
3135
3136webbrowser - a platform-independent API to launch a web browser.
3137
3138
Guido van Rossume905e952000-09-05 12:42:46 +00003139Changed Modules
3140---------------
3141
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003142array -- new methods for array objects: count, extend, index, pop, and
3143remove
3144
3145binascii -- new functions b2a_hex and a2b_hex that convert between
3146binary data and its hex representation
3147
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003148calendar -- Many new functions that support features including control
3149over which day of the week is the first day, returning strings instead
3150of printing them. Also new symbolic constants for days of week,
3151e.g. MONDAY, ..., SUNDAY.
3152
3153cgi -- FieldStorage objects have a getvalue method that works like a
3154dictionary's get method and returns the value attribute of the object.
3155
3156ConfigParser -- The parser object has new methods has_option,
3157remove_section, remove_option, set, and write. They allow the module
3158to be used for writing config files as well as reading them.
3159
3160ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003161optionally support the RFC 959 REST command.
3162
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003163gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003164
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003165httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3166the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003167
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003168locale -- implement getdefaultlocale for Win32 and Macintosh
3169
3170marshal -- no longer dumps core when marshaling deeply nested or
3171recursive data structures
3172
3173os -- new functions isatty, seteuid, setegid, setreuid, setregid
3174
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003175os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3176support under Unix.
3177
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003178os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003179
3180os.path -- fix semantics of os.path.commonprefix
3181
3182smtplib -- support for sending very long messages
3183
3184socket -- new function getfqdn()
3185
3186readline -- new functions to read, write and truncate history files.
3187The readline section of the library reference manual contains an
3188example.
3189
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003190select -- add interface to poll system call
3191
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003192shutil -- new copyfileobj function
3193
3194SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3195HTTP server.
3196
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003197Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003198
3199urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003200e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003201
3202whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003203
3204
3205Obsolete Modules
3206----------------
3207
3208None. However note that 1.6 made a whole slew of modules obsolete:
3209stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3210poly, zmod, strop, util, whatsound.
3211
3212
3213Changed, New, Obsolete Tools
3214----------------------------
3215
Tim Peters8b092332000-09-05 20:15:25 +00003216None.
Guido van Rossume905e952000-09-05 12:42:46 +00003217
3218
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003219C-level Changes
3220---------------
3221
3222Several cleanup jobs were carried out throughout the source code.
3223
3224All C code was converted to ANSI C; we got rid of all uses of the
3225Py_PROTO() macro, which makes the header files a lot more readable.
3226
3227Most of the portability hacks were moved to a new header file,
3228pyport.h; several other new header files were added and some old
3229header files were removed, in an attempt to create a more rational set
3230of header files. (Few of these ever need to be included explicitly;
3231they are all included by Python.h.)
3232
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003233Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003234and Win64, especially for the new Intel Itanium processor. Mick also
3235added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003236
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003237The C APIs to return an object's size have been update to consistently
3238use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3239previous versions, the abstract interfaces used PyXXX_Length and the
3240concrete interfaces used PyXXX_Size. The old names,
3241e.g. PyObject_Length, are still available for backwards compatibility
3242at the API level, but are deprecated.
3243
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003244The PyOS_CheckStack function has been implemented on Windows by
3245Fredrik Lundh. It prevents Python from failing with a stack overflow
3246on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003247
3248The GC changes resulted in creation of two new slots on object,
3249tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003250the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003251
3252The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003253C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003254
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003255PyErr_Format has been updated to automatically calculate the size of
3256the buffer needed to hold the formatted result string. This change
3257prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003258
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003259New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003260
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003261PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3262that are the same as their non-Ex counterparts except they take an
3263extra flag argument that tells them to close the file when done.
3264
3265XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003266
Tim Peters8b092332000-09-05 20:15:25 +00003267
3268Windows Changes
3269---------------
3270
3271New popen2/popen3/peopen4 in os module (see Changed Modules above).
3272
3273os.popen is much more usable on Windows 95 and 98. See Microsoft
3274Knowledge Base article Q150956. The Win9x workaround described there
3275is implemented by the new w9xpopen.exe helper in the root of your
3276Python installation. Note that Python uses this internally; it is not
3277a standalone program.
3278
3279Administrator privileges are no longer required to install Python
3280on Windows NT or Windows 2000. If you have administrator privileges,
3281Python's registry info will be written under HKEY_LOCAL_MACHINE.
3282Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003283under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003284uses of Python, but will prevent some advanced uses from working
3285(for example, running a Python script as an NT service, or possibly
3286from CGI).
3287
3288[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3289installer; instead, it installs the needed Tcl/Tk files directly in the
3290Python directory. If you already have a Tcl/Tk installation, this
3291wastes some disk space (about 4 Megs) but avoids problems with
3292conflicting Tcl/Tk installations, and makes it much easier for Python
3293to ensure that Tcl/Tk can find all its files.
3294
3295[This was new in 1.6] The Windows installer now installs by default in
3296\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3297
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003298
3299Updates to the changes between 1.5.2 and 1.6
3300--------------------------------------------
3301
3302The 1.6 NEWS file can't be changed after the release is done, so here
3303is some late-breaking news:
3304
3305New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3306and changes to getlocale() and setlocale().
3307
3308The new module is now enabled per default.
3309
3310It is not true that the encodings codecs cannot be used for normal
3311strings: the string.encode() (which is also present on 8-bit strings
3312!) allows using them for 8-bit strings too, e.g. to convert files from
3313cp1252 (Windows) to latin-1 or vice-versa.
3314
3315Japanese codecs are available from Tamito KAJIYAMA:
3316http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3317
3318
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003319======================================================================