blob: 72dd7923c1807362b47d7eca9e4fb518a0331bdf [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
Marc-André Lemburge92e0a92002-02-09 11:28:43 +00009- The UTF-8 codec will now encode and decode Unicode surrogates
10 correctly and without raising exceptions for unpaired ones.
11
Neal Norwitz649b7592002-01-01 19:07:13 +000012- file.xreadlines() now raises a ValueError if the file is closed:
13 Previously, an xreadlines object was returned which would raise
14 a ValueError when the xreadlines.next() method was called.
15
Tim Petersaf8446f2001-12-21 21:36:50 +000016Extension modules
17
Neal Norwitze790eae2002-01-01 21:14:12 +000018- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000019 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
20 is called.
21
Tim Petersaf8446f2001-12-21 21:36:50 +000022Library
23
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000024- encodings package: added aliases for all supported IANA character
25 sets
26
Guido van Rossum606fe4e2001-12-28 20:57:14 +000027- ftplib: to safeguard the user's privacy, anonymous login will use
28 "anonymous@" as default password, rather than the real user and host
29 name.
30
Fred Drake36736122002-01-10 13:50:31 +000031- webbrowser: tightened up the command passed to os.system() so that
32 arbitrary shell code can't be executed because a bogus URL was
33 passed in.
34
Tim Peters11bd9942002-02-01 00:52:29 +000035- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000036 gettext.find an optional all argument. Translations will now fallback
37 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000038
Martin v. Löwis9668b932002-01-12 11:27:42 +000039- distutils bdist commands now offer a --skip-build option.
40
Tim Petersaf8446f2001-12-21 21:36:50 +000041Tools/Demos
42
43Build
44
45C API
46
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000047- The "u#" parser marker will now pass through Unicode object as-is
48 without going through the buffer API.
49
Martin v. Löwis7198a522002-01-01 19:59:11 +000050- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
51
Tim Peters10a3bb52001-12-25 19:07:38 +000052- An old #define of ANY as void has been removed from pyport.h. This
53 hasn't been used since Python's pre-ANSI days, and the #define has
54 been marked as obsolete since then. SF bug 495548 says it created
55 conflicts with other packages, so keeping it around wasn't harmless.
56
Tim Petersaf8446f2001-12-21 21:36:50 +000057- Because Python's magic number scheme broke on January 1st, we decided
58 to stop Python development. Thanks for all the fish!
59
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000060- Some of us don't like fish, so we changed Python's magic number
61 scheme to a new one. See Python/import.c for details.
62
Tim Petersaf8446f2001-12-21 21:36:50 +000063New platforms
64
Martin v. Löwisa6e97582002-01-01 18:41:33 +000065- GNU/Hurd is now supported.
66
Tim Petersaf8446f2001-12-21 21:36:50 +000067Tests
68
69Windows
70
Tim Petersab034fa2002-02-01 11:27:43 +000071- os.waitpid() is now implemented for Windows, and can be used to block
72 until a specified process exits. This is similar to, but not exactly
73 the same as, os.waitpid() on POSIX systems. If you're waiting for
74 a specific process whose pid was obtained from one of the spawn()
75 functions, the same Python os.waitpid() code works across platforms.
76 See the docs for details.
77
Tim Peters11bd9942002-02-01 00:52:29 +000078- New tempfile.TemporaryFile implementation for Windows: this doesn't
79 need a TemproraryFileWrapper wrapper anymore, and should be immune
80 to a nasty problem: before 2.3, if you got a temp file on Windows, it
81 got wrapped in an object whose close() method first closed the
82 underlying file, then deleted the file. This usually worked fine.
83 However, the spawn family of functions on Windows create (at a low C
84 level) the same set of open files in the spawned process Q as were
85 open in the spawning process P. If a temp file f was among them, then
86 doing f.close() in P first closed P's C-level file handle on f, but Q's
87 C-level file handle on f remained open, so the attempt in P to delete f
88 blew up with a "Permission denied" error (Windows doesn't allow
89 deleting open files). This was surprising, subtle, and difficult to
90 work around.
91
92- The os module now exports all the symbolic constants usable with the
93 low-level os.open() on Windows: the new constants in 2.3 are
94 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
95 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
96 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
97 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
98 (so specify both if you want both; note that neither is useful unless
99 specified with O_CREAT too).
100
Tim Petersaf8446f2001-12-21 21:36:50 +0000101Mac
102
103
Tim Peters909c0912001-12-14 23:16:18 +0000104What's New in Python 2.2 final?
105Release date: 21-Dec-2001
106===============================
107
108Type/class unification and new-style classes
109
Barry Warsaw52acb492001-12-21 20:04:22 +0000110- pickle.py, cPickle: allow pickling instances of new-style classes
111 with a custom metaclass.
112
Tim Peters909c0912001-12-14 23:16:18 +0000113Core and builtins
114
Barry Warsaw52acb492001-12-21 20:04:22 +0000115- weakref proxy object: when comparing, unwrap both arguments if both
116 are proxies.
117
Tim Peters909c0912001-12-14 23:16:18 +0000118Extension modules
119
Barry Warsaw52acb492001-12-21 20:04:22 +0000120- binascii.b2a_base64(): fix a potential buffer overrun when encoding
121 very short strings.
122
123- cPickle: the obscure "fast" mode was suspected of causing stack
124 overflows on the Mac. Hopefully fixed this by setting the recursion
125 limit much smaller. If the limit is too low (it only affects
126 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
127 when compiling cPickle.c (or in pyconfig.h).
128
Tim Peters909c0912001-12-14 23:16:18 +0000129Library
130
Barry Warsaw52acb492001-12-21 20:04:22 +0000131- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
132 close or delete time).
133
134- rfc822.py: fixed a bug where the address '<>' was converted to None
135 instead of an empty string (also fixes the email.Utils module).
136
137- xmlrpclib.py: version 1.0.0; uses precision for doubles.
138
139- test suite: the pickle and cPickle tests were not executing any code
140 when run from the standard regresssion test.
141
Tim Peters909c0912001-12-14 23:16:18 +0000142Tools/Demos
143
144Build
145
146C API
147
148New platforms
149
150Tests
151
152Windows
153
Barry Warsaw52acb492001-12-21 20:04:22 +0000154- distutils package: fixed broken Windows installers (bdist_wininst).
155
156- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
157 instances are deleted at process exit time.
158
159- socket.py: prevent mysterious warnings when socket instances are
160 deleted at process exit time.
161
162- posixmodule.c: fix a Windows crash with stat() of a filename ending
163 in backslash.
164
Tim Peters909c0912001-12-14 23:16:18 +0000165Mac
166
Barry Warsaw52acb492001-12-21 20:04:22 +0000167- The Carbon toolbox modules have been upgraded to Universal Headers
168 3.4, and experimental CoreGraphics and CarbonEvents modules have
169 been added. All only for framework-enabled MacOSX.
170
Tim Peters909c0912001-12-14 23:16:18 +0000171
Tim Peters6272dfd2001-12-13 19:34:00 +0000172What's New in Python 2.2c1?
173Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000174===========================
175
176Type/class unification and new-style classes
177
Barry Warsaw06557452001-12-14 20:47:12 +0000178- Guido's tutorial introduction to the new type/class features has
179 been extensively updated. See
180
181 http://www.python.org/2.2/descrintro.html
182
183 That remains the primary documentation in this area.
184
Guido van Rossum33bab012001-12-05 22:45:48 +0000185- Fixed a leak: instance variables declared with __slots__ were never
186 deleted!
187
Guido van Rossum4b800852001-12-03 00:54:52 +0000188- The "delete attribute" method of descriptor objects is called
189 __delete__, not __del__. In previous releases, it was mistakenly
190 called __del__, which created an unfortunate overloading condition
191 with finalizers. (The "get attribute" and "set attribute" methods
192 are still called __get__ and __set__, respectively.)
193
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000194- Some subtle issues with the super built-in were fixed:
195
196 (a) When super itself is subclassed, its __get__ method would still
197 return an instance of the base class (i.e., of super).
198
199 (b) super(C, C()).__class__ would return C rather than super. This
200 is confusing. To fix this, I decided to change the semantics of
201 super so that it only applies to code attributes, not to data
202 attributes. After all, overriding data attributes is not
203 supported anyway.
204
205 (c) The __get__ method didn't check whether the argument was an
206 instance of the type used in creation of the super instance.
207
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000208- Previously, hash() of an instance of a subclass of a mutable type
209 (list or dictionary) would return some value, rather than raising
210 TypeError. This has been fixed. Also, directly calling
211 dict.__hash__ and list.__hash__ now raises the same TypeError
212 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000213
Guido van Rossumd331cb52001-12-05 19:46:42 +0000214- New-style objects now support deleting their __dict__. This is for
215 all intents and purposes equivalent to assigning a brand new empty
216 dictionary, but saves space if the object is not used further.
217
Tim Petersb3c9af12001-11-17 00:21:57 +0000218Core and builtins
219
Tim Peters3caca232001-12-06 06:23:26 +0000220- -Qnew now works as documented in PEP 238: when -Qnew is passed on
221 the command line, all occurrences of "/" use true division instead
222 of classic division. See the PEP for details. Note that "all"
223 means all instances in library and 3rd-party modules, as well as in
224 your own code. As the PEP says, -Qnew is intended for use only in
225 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000226 Note that test_coercion.py in the standard Python test suite fails
227 under -Qnew; this is expected, and won't be repaired until true
228 division becomes the default (in the meantime, test_coercion is
229 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000230
Fred Drake6c01e252001-12-14 17:08:12 +0000231- complex() now only allows the first argument to be a string
232 argument, and raises TypeError if either the second arg is a string
233 or if the second arg is specified when the first is a string.
234
Tim Petersb3c9af12001-11-17 00:21:57 +0000235Extension modules
236
Martin v. Löwis560da622001-11-24 09:24:51 +0000237- gc.get_referents was renamed to gc.get_referrers.
238
Tim Petersb3c9af12001-11-17 00:21:57 +0000239Library
240
Tim Peters25059d32001-12-07 20:35:43 +0000241- Functions in the os.spawn() family now release the global interpreter
242 lock around calling the platform spawn. They should always have done
243 this, but did not before 2.2c1. Multithreaded programs calling
244 an os.spawn function with P_WAIT will no longer block all Python threads
245 until the spawned program completes. It's possible that some programs
246 relies on blocking, although more likely by accident than by design.
247
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000248- webbrowser defaults to netscape.exe on OS/2 now.
249
Martin v. Löwis652e1912001-11-25 14:50:56 +0000250- Tix.ResizeHandle exposes detach_widget, hide, and show.
251
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000252- The charset alias windows_1252 has been added.
253
Barry Warsaw06557452001-12-14 20:47:12 +0000254- types.StringTypes is a tuple containing the defined string types;
255 usually this will be (str, unicode), but if Python was compiled
256 without Unicode support it will be just (str,).
257
258- The pulldom and minidom modules were synchronized to PyXML.
259
Tim Petersb3c9af12001-11-17 00:21:57 +0000260Tools/Demos
261
Barry Warsaw06557452001-12-14 20:47:12 +0000262- A new script called Tools/scripts/google.py was added, which fires
263 off a search on Google.
264
Tim Petersb3c9af12001-11-17 00:21:57 +0000265Build
266
Barry Warsaw06557452001-12-14 20:47:12 +0000267- Note that release builds of Python should arrange to define the
268 preprocessor symbol NDEBUG on the command line (or equivalent).
269 In the 2.2 pre-release series we tried to define this by magic in
270 Python.h instead, but it proved to cause problems for extension
271 authors. The Unix, Windows and Mac builds now all define NDEBUG in
272 release builds via cmdline (or equivalent) instead. Ports to
273 other platforms should do likewise.
274
Jack Jansen1999ef42001-12-06 21:47:20 +0000275- It is no longer necessary to use --with-suffix when building on a
276 case-insensitive file system (such as Mac OS X HFS+). In the build
277 directory an extension is used, but not in the installed python.
278
Tim Petersb3c9af12001-11-17 00:21:57 +0000279C API
280
Tim Petersf582b822001-12-11 18:51:08 +0000281- New function PyDict_MergeFromSeq2() exposes the builtin dict
282 constructor's logic for updating a dictionary from an iterable object
283 producing key-value pairs.
284
Tim Peterscffed4b2001-11-29 03:26:37 +0000285- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000286 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000287 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
288 dump core in some bad cases. This has been repaired. As a result,
289 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
290 previously went unchallenged.
291
Tim Petersb3c9af12001-11-17 00:21:57 +0000292New platforms
293
294Tests
295
296Windows
297
298Mac
299
Jack Jansenffa260f2001-12-06 21:14:00 +0000300- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
301 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000302
Barry Warsaw06557452001-12-14 20:47:12 +0000303- Changed logic for finding python home in Mac OS X framework Pythons.
304 Now sys.executable points to the executable again, in stead of to
305 the shared library. The latter is used only for locating the python
306 home.
307
308
Tim Peters84362bc2001-10-19 17:55:30 +0000309What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000310Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000311===========================
312
313Type/class unification and new-style classes
314
Guido van Rossum3d27df02001-11-15 20:27:54 +0000315- Multiple inheritance mixing new-style and classic classes in the
316 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000317
318 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000319 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000320
321 The MRO (method resolution order) for each base class is respected
322 according to its kind, but the MRO for the derived class is computed
323 using new-style MRO rules if any base clase is a new-style class.
324 This needs to be documented.
325
Tim Petersa427a2b2001-10-29 22:25:45 +0000326- The new builtin dictionary() constructor, and dictionary type, have
327 been renamed to dict. This reflects a decade of common usage.
328
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000329- dict() now accepts an iterable object producing 2-sequences. For
330 example, dict(d.items()) == d for any dictionary d. The argument,
331 and the elements of the argument, can be any iterable objects.
332
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000333- New-style classes can now have a __del__ method, which is called
334 when the instance is deleted (just like for classic classes).
335
Guido van Rossum12d955c2001-10-26 14:56:06 +0000336- Assignment to object.__dict__ is now possible, for objects that are
337 instances of new-style classes that have a __dict__ (unless the base
338 class forbids it).
339
Guido van Rossumc8e56452001-10-22 00:43:43 +0000340- Methods of built-in types now properly check for keyword arguments
341 (formerly these were silently ignored). The only built-in methods
342 that take keyword arguments are __call__, __init__ and __new__.
343
Guido van Rossum86443212001-10-27 22:28:54 +0000344- The socket function has been converted to a type; see below.
345
Tim Peters84362bc2001-10-19 17:55:30 +0000346Core and builtins
347
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000348- Assignment to __debug__ raises SyntaxError at compile-time. This
349 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000350 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000351
Guido van Rossum12d955c2001-10-26 14:56:06 +0000352- Clarified the error messages for unsupported operands to an operator
353 (like 1 + '').
354
Tim Peters84362bc2001-10-19 17:55:30 +0000355Extension modules
356
Tim Peters5ebfd362001-11-13 23:11:19 +0000357- mmap has a new keyword argument, "access", allowing a uniform way for
358 both Windows and Unix users to create read-only, write-through and
359 copy-on-write memory mappings. This was previously possible only on
360 Unix. A new keyword argument was required to support this in a
361 uniform way because the mmap() signuatures had diverged across
362 platforms. Thanks to Jay T Miller for repairing this!
363
Tim Peters169ded02001-11-03 19:57:21 +0000364- By default, the gc.garbage list now contains only those instances in
365 unreachable cycles that have __del__ methods; in 2.1 it contained all
366 instances in unreachable cycles. "Instances" here has been generalized
367 to include instances of both new-style and old-style classes.
368
Guido van Rossum12d955c2001-10-26 14:56:06 +0000369- The socket module defines a new method for socket objects,
370 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000371 send() until all data has been sent. Also, the socket function has
372 been converted to a subclassable type, like list and tuple (etc.)
373 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000374
375- Various bugfixes to the curses module. There is now a test suite
376 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000377
Guido van Rossum692adf12001-10-30 03:03:03 +0000378- binascii.b2a_base64 no longer places an arbitrary restriction of 57
379 bytes on its input.
380
Tim Peters84362bc2001-10-19 17:55:30 +0000381Library
382
Tim Peters5ebfd362001-11-13 23:11:19 +0000383- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000384 convenience function.
385
Tim Peters75335872001-11-03 19:35:43 +0000386- Symbolic group names in regular expressions must be unique. For
387 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
388 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000389 Python 2.2 detects this error at regexp compilation time;
390 previously, the error went undetected, and results were
391 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
392 pattern.subn() methods have been rewritten in C. Also, an
393 experimental function/method finditer() has been added, which works
394 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000395
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000396- Tix exposes more commands through the classes DirSelectBox,
397 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
398 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
399 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
400
Tim Peters98791af2001-10-23 01:59:54 +0000401- Traceback objects are now scanned by cyclic garbage collection, so
402 cycles created by casual use of sys.exc_info() no longer cause
403 permanent memory leaks (provided garbage collection is enabled).
404
Guido van Rossum49192142001-10-24 20:51:44 +0000405- os.extsep -- a new variable needed by the RISCOS support. It is the
406 separator used by extensions, and is '.' on all platforms except
407 RISCOS, where it is '/'. There is no need to use this variable
408 unless you have a masochistic desire to port your code to RISCOS.
409
Barry Warsaw012852b2001-11-16 16:17:27 +0000410- mimetypes.py has optional support for non-standard, but commonly
411 found types. guess_type() and guess_extension() now accept an
412 optional `strict' flag, defaulting to true, which controls whether
413 recognize non-standard types or not. A few non-standard types we
414 know about have been added. Also, when run as a script, there are
415 new -l and -e options.
416
417- statcache is now deprecated.
418
419- email.Utils.formatdate() now produces the preferred RFC 2822 style
420 dates with numeric timezones (it used to produce obsolete dates
421 hard coded to "GMT" timezone). An optional `localtime' flag is
422 added to produce dates in the local timezone, with daylight savings
423 time properly taken into account.
424
425- In pickle and cPickle, instead of masking errors in load() by
426 transforming them into SystemError, we let the original exception
427 propagate out. Also, implement support for __safe_for_unpickling__
428 in pickle, as it already was supported in cPickle.
429
Tim Peters84362bc2001-10-19 17:55:30 +0000430Tools/Demos
431
432Build
433
Barry Warsaw012852b2001-11-16 16:17:27 +0000434- The dbm module is built using libdb1 if available. The bsddb module
435 is built with libdb3 if available.
436
437- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
438
Tim Peters84362bc2001-10-19 17:55:30 +0000439C API
440
Tim Peters1fc240e2001-10-26 05:06:50 +0000441- New function PySequence_Fast_GET_SIZE() returns the size of a non-
442 NULL result from PySequence_Fast(), more quickly than calling
443 PySequence_Size().
444
Barry Warsaw012852b2001-11-16 16:17:27 +0000445- New argument unpacking function PyArg_UnpackTuple() added.
446
447- New functions PyObject_CallFunctionObjArgs() and
448 PyObject_CallMethodObjArgs() have been added to make it more
449 convenient and efficient to call functions and methods from C.
450
451- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
452 possible that this will propagate errors it didn't before.
453
454- New function PyObject_CheckReadBuffer(), which returns true if its
455 argument supports the single-segment readable buffer interface.
456
Tim Peters84362bc2001-10-19 17:55:30 +0000457New platforms
458
Guido van Rossum86443212001-10-27 22:28:54 +0000459- We've finally confirmed that this release builds on HP-UX 11.00,
460 *with* threads, and passes the test suite.
461
Tim Peters7a33d8b2001-11-05 02:51:07 +0000462- Thanks to a series of patches from Michael Muller, Python may build
463 again under OS/2 Visual Age C++.
464
Guido van Rossum49192142001-10-24 20:51:44 +0000465- Updated RISCOS port by Dietmar Schwertberger.
466
Tim Peters84362bc2001-10-19 17:55:30 +0000467Tests
468
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000469- Added a test script for the curses module. It isn't run automatically;
470 regrtest.py must be run with '-u curses' to enable it.
471
Tim Peters84362bc2001-10-19 17:55:30 +0000472Windows
473
Barry Warsaw012852b2001-11-16 16:17:27 +0000474Mac
475
476- PythonScript has been moved to unsupported and is slated to be
477 removed completely in the next release.
478
479- It should now be possible to build applets that work on both OS9 and
480 OSX.
481
482- The core is now linked with CoreServices not Carbon; as a side
483 result, default 8bit encoding on OSX is now ASCII.
484
485- Python should now build on OSX 10.1.1
486
Tim Peters84362bc2001-10-19 17:55:30 +0000487
Tim Petersabf925f2001-09-28 21:53:42 +0000488What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000489Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000490===========================
491
492Type/class unification and new-style classes
493
Guido van Rossum687ae002001-10-15 22:03:32 +0000494- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000495 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000496 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000497 remains: the __dict__ of a new-style class is a read-only proxy; you
498 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000499 __defined__ attribute of new-style types no longer exists, for lack
500 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000501 future a __cache__ may be resurrected with a similar function, if I
502 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000503
Tim Peters1c9ca872001-10-04 06:43:12 +0000504- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
505 always returned None, even when there was a class docstring).
506
507- doctest now finds and runs docstrings attached to new-style classes,
508 class methods, static methods, and properties.
509
Guido van Rossum9074ef62001-10-16 21:34:49 +0000510Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000511
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000512- A very subtle syntactical pitfall in list comprehensions was fixed.
513 For example: [a+b for a in 'abc', for b in 'def']. The comma in
514 this example is a mistake. Previously, this would silently let 'a'
515 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
516 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
517 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
518 Note that [a for a in <singleton>] is a convoluted way to say
519 [<singleton>] anyway, so it's not like any expressiveness is lost.
520
Guido van Rossum9074ef62001-10-16 21:34:49 +0000521- getattr(obj, name, default) now only catches AttributeError, as
522 documented, rather than returning the default value for all
523 exceptions (which could mask bugs in a __getattr__ hook, for
524 example).
525
Fred Drakecb7a6b52001-10-22 18:41:51 +0000526- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000527 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000528 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000529 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000530
Guido van Rossum1c486092001-10-19 02:05:35 +0000531- unicode(obj) now behaves more like str(obj), accepting arbitrary
532 objects, and calling a __unicode__ method if it exists.
533 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000534 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000535
Barry Warsawf6fb1712001-10-19 05:35:40 +0000536- isinstance() now allows any object as the first argument and a
537 class, a type or something with a __bases__ tuple attribute for the
538 second argument. The second argument may also be a tuple of a
539 class, type, or something with __bases__, in which case isinstance()
540 will return true if the first argument is an instance of any of the
541 things contained in the second argument tuple. E.g.
542
543 isinstance(x, (A, B))
544
545 returns true if x is an instance of A or B.
546
Guido van Rossum9074ef62001-10-16 21:34:49 +0000547Extension modules
548
549- thread.start_new_thread() now returns the thread ID (previously None).
550
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000551- binascii has now two quopri support functions, a2b_qp and b2a_qp.
552
Guido van Rossumc524d952001-10-19 01:31:59 +0000553- readline now supports setting the startup_hook and the
554 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000555
Guido van Rossumc524d952001-10-19 01:31:59 +0000556- os and posix supports chroot(), setgroups() and unsetenv() where
557 available. The stat(), fstat(), statvfs() and fstatvfs() functions
558 now return "pseudo-sequences" -- the various fields can now be
559 accessed as attributes (e.g. os.stat("/").st_mtime) but for
560 backwards compatibility they also behave as a fixed-length sequence.
561 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000562 attributes.
563
564- time: localtime(), gmtime() and strptime() now return a
565 pseudo-sequence similar to the os.stat() return value, with
566 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000567
Guido van Rossum9074ef62001-10-16 21:34:49 +0000568- Decompression objects in the zlib module now accept an optional
569 second parameter to decompress() that specifies the maximum amount
570 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000571
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000572- optional SSL support in the socket module now exports OpenSSL
573 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
574 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000575 automatically seed its PRNG. Also, the keyfile and certfile
576 arguments to socket.ssl() are now optional.
577
578- posixmodule (and by extension, the os module on POSIX platforms) now
579 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000580
Guido van Rossum9074ef62001-10-16 21:34:49 +0000581Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000582
Tim Peters7402f792001-10-02 03:53:41 +0000583- doctest now excludes functions and classes not defined by the module
584 being tested, thanks to Tim Hochberg.
585
Fred Drakecb7a6b52001-10-22 18:41:51 +0000586- HotShot, a new profiler implemented using a C-based callback, has
587 been added. This substantially reduces the overhead of profiling,
588 but it is still quite preliminary. Support modules and
589 documentation will be added in upcoming releases (before 2.2 final).
590
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000591- profile now produces correct output in situations where an exception
592 raised in Python is cleared by C code (e.g. hasattr()). This used
593 to cause wrong output, including spurious claims of recursive
594 functions and attribution of time spent to the wrong function.
595
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000596 The code and documentation for the derived OldProfile and HotProfile
597 profiling classes was removed. The code hasn't worked for years (if
598 you tried to use them, they raised exceptions). OldProfile
599 intended to reproduce the behavior of the profiler Python used more
600 than 7 years ago, and isn't interesting anymore. HotProfile intended
601 to provide a faster profiler (but producing less information), and
602 that's a worthy goal we intend to meet via a different approach (but
603 without losing information).
604
Tim Peterscce092d2001-10-09 05:31:56 +0000605- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000606 a much better system-specific calibration constant. The constant can
607 now be specified in an instance constructor, or as a Profile class or
608 instance variable, instead of by editing profile.py's source code.
609 Calibration must still be done manually (see the docs for the profile
610 module).
611
612 Note that Profile.calibrate() must be overriden by subclasses.
613 Improving the accuracy required exploiting detailed knowledge of
614 profiler internals; the earlier method abstracted away the details
615 and measured a simplified model instead, but consequently computed
616 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000617
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000618- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000619 which indicates whether output is intended for the header 'Q'
620 encoding.
621
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000622- The SocketServer.ThreadingMixIn class now closes the request after
623 finish_request() returns. (Not when it errors out though.)
624
Barry Warsawf6fb1712001-10-19 05:35:40 +0000625- The nntplib module's NNTP.body() method has grown a `file' argument
626 to allow saving the message body to a file.
627
628- The email package has added a class email.Parser.HeaderParser which
629 only parses headers and does not recurse into the message's body.
630 Also, the module/class MIMEAudio has been added for representing
631 audio data (contributed by Anthony Baxter).
632
633- ftplib should be able to handle files > 2GB.
634
635- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
636 ON, and OFF.
637
Fred Drakecb7a6b52001-10-22 18:41:51 +0000638- xml.dom.minidom NodeList objects now support the length attribute
639 and item() method as required by the DOM specifications.
640
Guido van Rossumed554f62001-10-02 23:15:37 +0000641Tools/Demos
642
643- Demo/dns was removed. It no longer serves any purpose; a package
644 derived from it is now maintained by Anthony Baxter, see
645 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000646
Barry Warsawf6fb1712001-10-19 05:35:40 +0000647- The freeze tool has been made more robust, and two new options have
648 been added: -X and -E.
649
Tim Petersabf925f2001-09-28 21:53:42 +0000650Build
651
Barry Warsawf6fb1712001-10-19 05:35:40 +0000652- configure will use CXX in LINKCC if CXX is used to build main() and
653 the system requires to link a C++ main using the C++ compiler.
654
Tim Petersabf925f2001-09-28 21:53:42 +0000655C API
656
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000657- The documentation for the tp_compare slot is updated to require that
658 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
659 not correct. This is not yet enforced but will be enforced in
660 Python 2.3; even later, we may use -2 to indicate errors and +2 for
661 "NotImplemented". Right now, -1 should be used for an error return.
662
Tim Petersd38b1c72001-09-30 05:09:37 +0000663- PyLong_AsLongLong() now accepts int (as well as long) arguments.
664 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
665 as long) arguments.
666
Guido van Rossum3c288632001-10-16 21:13:49 +0000667- PyThread_start_new_thread() now returns a long int giving the thread
668 ID, if one can be calculated; it returns -1 for error, 0 if no
669 thread ID is calculated (this is an incompatible change, but only
670 the thread module used this API). This code has only really been
671 tested on Linux and Windows; other platforms please beware (and
672 report any bugs or strange behavior).
673
Guido van Rossum1c486092001-10-19 02:05:35 +0000674- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
675 input.
676
Tim Petersabf925f2001-09-28 21:53:42 +0000677New platforms
678
679Tests
680
681Windows
682
Tim Peters04cf1d32001-10-09 22:39:40 +0000683- Installer: If you install IDLE, and don't disable file-extension
684 registration, a new "Edit with IDLE" context (right-click) menu entry
685 is created for .py and .pyw files.
686
Tim Peters1ce3cf72001-10-01 17:58:40 +0000687- The signal module now supports SIGBREAK on Windows, thanks to Steven
688 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
689 action remains to call Win32 ExitProcess(). This can be changed via
690 signal.signal(). For example:
691
692 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
693 # (SIGINT) behavior.
694 import signal
695 signal.signal(signal.SIGBREAK,
696 signal.default_int_handler)
697
698 try:
699 while 1:
700 pass
701 except KeyboardInterrupt:
702 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
703 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
704 # program without the possibility for any Python-level cleanup).
705 print "Clean exit"
706
Tim Petersabf925f2001-09-28 21:53:42 +0000707
Tim Petersb07352e2001-09-08 01:25:47 +0000708What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000709Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000710===========================
711
Guido van Rossum808eea72001-09-25 04:15:41 +0000712Type/class unification and new-style classes
713
714- pydoc and inspect are now aware of new-style classes;
715 e.g. help(list) at the interactive prompt now shows proper
716 documentation for all operations on list objects.
717
718- Applications using Jim Fulton's ExtensionClass module can now safely
719 be used with Python 2.2. In particular, Zope 2.4.1 now works with
720 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
721 examples also work again. It is hoped that Gtk and Boost also work
722 with 2.2a4 and beyond. (If you can confirm this, please write
723 webmaster@python.org; if there are still problems, please open a bug
724 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000725
Tim Peters66c1a522001-09-24 21:17:50 +0000726- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
727 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
728 in the constructed property object. fget, fset and fdel weren't
729 discoverable from Python in 2.2a3. __doc__ is new, and allows to
730 associate a docstring with a property.
731
Guido van Rossum808eea72001-09-25 04:15:41 +0000732- Comparison overloading is now more completely implemented. For
733 example, a str subclass instance can properly be compared to a str
734 instance, and it can properly overload comparison. Ditto for most
735 other built-in object types.
736
737- The repr() of new-style classes has changed; instead of <type
738 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
739 *except* for built-in types, which are still rendered as <type
740 'Foo'> (to avoid upsetting existing code that might parse or
741 otherwise rely on repr() of certain type objects).
742
743- The repr() of new-style objects is now always <Foo object at XXX>;
744 previously, it was sometimes <Foo instance at XXX>.
745
746- For new-style classes, what was previously called __getattr__ is now
747 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000748 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000749 one in classic classes is defined which is called only if regular
750 attribute access raises AttributeError; to catch *all* attribute
751 access, you can use __getattribute__ (for new-style classes). If
752 both are defined, __getattribute__ is called first, and if it raises
753 AttributeError, __getattr__ is called.
754
755- The __class__ attribute of new-style objects can be assigned to.
756 The new class must have the same C-level object layout as the old
757 class.
758
759- The builtin file type can be subclassed now. In the usual pattern,
760 "file" is the name of the builtin type, and file() is a new builtin
761 constructor, with the same signature as the builtin open() function.
762 file() is now the preferred way to open a file.
763
764- Previously, __new__ would only see sequential arguments passed to
765 the type in a constructor call; __init__ would see both sequential
766 and keyword arguments. This made no sense whatsoever any more, so
767 now both __new__ and __init__ see all arguments.
768
769- Previously, hash() applied to an instance of a subclass of str or
770 unicode always returned 0. This has been repaired.
771
772- Previously, an operation on an instance of a subclass of an
773 immutable type (int, long, float, complex, tuple, str, unicode),
774 where the subtype didn't override the operation (and so the
775 operation was handled by the builtin type), could return that
776 instance instead a value of the base type. For example, if s was of
777 a str sublass type, s[:] returned s as-is. Now it returns a str
778 with the same value as s.
779
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000780- Provisional support for pickling new-style objects has been added.
781
Guido van Rossum808eea72001-09-25 04:15:41 +0000782Core
783
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000784- file.writelines() now accepts any iterable object producing strings.
785
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000786- PyUnicode_FromEncodedObject() now works very much like
787 PyObject_Str(obj) in that it tries to use __str__/tp_str
788 on the object if the object is not a string or buffer. This
789 makes unicode() behave like str() when applied to non-string/buffer
790 objects.
791
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000792- PyFile_WriteObject now passes Unicode objects to the file's write
793 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000794 of a print statement must support Unicode objects, i.e. they must
795 at least convert them into ASCII strings.
796
Guido van Rossum624c8af2001-09-18 15:21:04 +0000797- Thread scheduling on Solaris should be improved; it is no longer
798 necessary to insert a small sleep at the start of a thread in order
799 to let other runnable threads be scheduled.
800
Tim Petersb07352e2001-09-08 01:25:47 +0000801Library
802
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000803- StringIO.StringIO instances and cStringIO.StringIO instances support
804 read character buffer compatible objects for their .write() methods.
805 These objects are converted to strings and then handled as such
806 by the instances.
807
Barry Warsaw2f600732001-09-24 04:28:10 +0000808- The "email" package has been added. This is basically a port of the
809 mimelib package <http://sf.net/projects/mimelib> with API changes
810 and some implementations updated to use iterators and generators.
811
Tim Peters8a9c2842001-09-22 21:30:22 +0000812- difflib.ndiff() and difflib.Differ.compare() are generators now. This
813 restores the ability of Tools/scripts/ndiff.py to start producing output
814 before the entire comparison is complete.
815
Barry Warsaw58b072d2001-09-22 04:44:21 +0000816- StringIO.StringIO instances and cStringIO.StringIO instances support
817 iteration just like file objects (i.e. their .readline() method is
818 called for each iteration until it returns an empty string).
819
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000820- The codecs module has grown four new helper APIs to access
821 builtin codecs: getencoder(), getdecoder(), getreader(),
822 getwriter().
823
Guido van Rossum624c8af2001-09-18 15:21:04 +0000824- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
825 simplifies writing XML RPC servers.
826
Barry Warsaw647d5e82001-09-28 17:01:02 +0000827- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000828 after interpretation of symbolic links. On non-Unix systems, this
829 is an alias for os.path.abspath().
830
Tim Peters16a77ad2001-09-08 04:00:12 +0000831- operator.indexOf() (PySequence_Index() in the C API) now works with any
832 iterable object.
833
Guido van Rossum624c8af2001-09-18 15:21:04 +0000834- smtplib now supports various authentication and security features of
835 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000836
Guido van Rossum624c8af2001-09-18 15:21:04 +0000837- hmac: a new module implementing keyed hashing for message
838 authentication.
839
840- mimetypes now recognizes more extensions and file types. At the
841 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000842
Guido van Rossum624c8af2001-09-18 15:21:04 +0000843- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000844 Python 2.2 bytecode generation. It has also been promoted from a
845 Tool to a standard library package. (Tools/compiler still exists as
846 a sample driver.)
847
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000848Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000849
Tim Petersb07352e2001-09-08 01:25:47 +0000850Build
851
Guido van Rossum624c8af2001-09-18 15:21:04 +0000852- Large file support (LFS) is now automatic when the platform supports
853 it; no more manual configuration tweaks are needed. On Linux, at
854 least, it's possible to have a system whose C library supports large
855 files but whose kernel doesn't; in this case, large file support is
856 still enabled but doesn't do you any good unless you upgrade your
857 kernel or share your Python executable with another system whose
858 kernel has large file support.
859
860- The configure script now supplies plausible defaults in a
861 cross-compilation environment. This doesn't mean that the supplied
862 values are always correct, or that cross-compilation now works
863 flawlessly -- but it's a first step (and it shuts up most of
864 autoconf's warnings about AC_TRY_RUN).
865
866- The Unix build is now a bit less chatty, courtesy of the parser
867 generator. The build is completely silent (except for errors) when
868 using "make -s", thanks to a -q option to setup.py.
869
Tim Petersb07352e2001-09-08 01:25:47 +0000870C API
871
Guido van Rossum624c8af2001-09-18 15:21:04 +0000872- The "structmember" API now supports some new flag bits to deny read
873 and/or write access to attributes in restricted execution mode.
874
Tim Petersb07352e2001-09-08 01:25:47 +0000875New platforms
876
Guido van Rossum624c8af2001-09-18 15:21:04 +0000877- Compaq's iPAQ handheld, running the "familiar" Linux distribution
878 (http://familiar.handhelds.org).
879
Tim Petersb07352e2001-09-08 01:25:47 +0000880Tests
881
Tim Peters8a9c2842001-09-22 21:30:22 +0000882- The "classic" standard tests, which work by comparing stdout to
883 an expected-output file under Lib/test/output/, no longer stop at
884 the first mismatch. Instead the test is run to completion, and a
885 variant of ndiff-style comparison is used to report all differences.
886 This is much easier to understand than the previous style of reporting.
887
888- The unittest-based standard tests now use regrtest's test_main()
889 convention, instead of running as a side-effect of merely being
890 imported. This allows these tests to be run in more natural and
891 flexible ways as unittests, outside the regrtest framework.
892
893- regrtest.py is much better integrated with unittest and doctest now,
894 especially in regard to reporting errors.
895
Tim Petersb07352e2001-09-08 01:25:47 +0000896Windows
897
Guido van Rossum624c8af2001-09-18 15:21:04 +0000898- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000899 that support it (NTFS under Windows 2000). See "What's New in
900 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000901
Tim Petersb07352e2001-09-08 01:25:47 +0000902
Tim Petersedc99312001-08-22 21:36:50 +0000903What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000904Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000905===========================
906
907Core
908
Tim Peters9fffa3e2001-09-04 05:14:19 +0000909- Conversion of long to float now raises OverflowError if the long is too
910 big to represent as a C double.
911
Tim Peters32f453e2001-09-03 08:35:41 +0000912- The 3-argument builtin pow() no longer allows a third non-None argument
913 if either of the first two arguments is a float, or if both are of
914 integer types and the second argument is negative (in which latter case
915 the arguments are converted to float, so this is really the same
916 restriction).
917
Tim Peters5d2b77c2001-09-03 05:47:38 +0000918- The builtin dir() now returns more information, and sometimes much
919 more, generally naming all attributes of an object, and all attributes
920 reachable from the object via its class, and from its class's base
921 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
922 an empty list. In 2.2a3,
923
924 >>> dir([])
925 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
926 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
927 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
928 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
929 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
930 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
931 'reverse', 'sort']
932
933 dir(module) continues to return only the module's attributes, though.
934
Tim Petersbdee63f2001-09-02 03:40:59 +0000935- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000936 than raising OverflowError. This is a partial implementation of PEP
937 237. You can use -Wdefault::OverflowWarning to enable a warning for
938 this situation, and -Werror::OverflowWarning to revert to the old
939 OverflowError exception.
940
Guido van Rossum61c345f2001-09-04 03:26:15 +0000941- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000942 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000943 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
944 -Qold, meaning the / operator has its classic meaning and no
945 warnings are issued. Using -Qwarn issues a run-time warning about
946 all uses of classic division for int and long arguments; -Qwarnall
947 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000948 (for use with fixdiv.py).
949 [Note: the remainder of this paragraph (preserved below) became
950 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
951 <obsolete>
952 Using -Qnew is questionable; it turns on new division by default, but
953 only in the __main__ module. You can usefully combine -Qwarn or
954 -Qwarnall and -Qnew: this gives the __main__ module new division, and
955 warns about classic division everywhere else.
956 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000957
Tim Petersbdee63f2001-09-02 03:40:59 +0000958- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000959 long, float, str, unicode, and tuple. (The types complex, list and
960 dictionary can also be subclassed; this was introduced earlier.)
961 Note that restrictions apply when subclassing immutable built-in
962 types: you can only affect the value of the instance by overloading
963 __new__. You can add mutable attributes, and the subclass instances
964 will have a __dict__ attribute, but you cannot change the "value"
965 (as implemented by the base class) of an immutable subclass instance
966 once it is created.
967
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000968- The dictionary constructor now takes an optional argument, a
969 mapping-like object, and initializes the dictionary from its
970 (key, value) pairs.
971
Tim Petersbdee63f2001-09-02 03:40:59 +0000972- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000973 "cooperative super calls" in a multiple inheritance setting. For an
974 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
975
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000976- A new built-in type, property, has been added. This enables the
977 creation of "properties". These are attributes implemented by
978 getter and setter functions (or only one of these for read-only or
979 write-only attributes), without the need to override __getattr__.
980 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000981
Tim Petersbdee63f2001-09-02 03:40:59 +0000982- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000983 liberalized, to allow leading zeroes. Examples of literals now
984 legal that were SyntaxErrors before:
985
986 00.0 0e3 0100j 07.5 00000000000000000008.
987
Tim Petersbdee63f2001-09-02 03:40:59 +0000988- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000989 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
990
Tim Petersedc99312001-08-22 21:36:50 +0000991Library
992
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000993- telnetlib includes symbolic names for the options, and support for
994 setting an option negotiation callback.
995
Tim Petersa40c7932001-09-05 22:36:56 +0000996- The new C standard no longer requires that math libraries set errno to
997 ERANGE on overflow. For platform libraries that exploit this new
998 freedom, Python's overflow-checking was wholly broken. A new overflow-
999 checking scheme attempts to repair that, but may not be reliable on all
1000 platforms (C doesn't seem to provide anything both useful and portable
1001 in this area anymore).
1002
Martin v. Löwis44f86962001-09-05 13:44:54 +00001003- Asynchronous timeout actions are available through the new class
1004 threading.Timer.
1005
Tim Peters78526162001-09-05 00:53:45 +00001006- math.log and math.log10 now return sensible results for even huge
1007 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1008
Tim Petersbdee63f2001-09-02 03:40:59 +00001009- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001010 currently held. See the docs for the imp module.
1011
Tim Petersbdee63f2001-09-02 03:40:59 +00001012- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001013 dumps containing ints written on platforms where Python ints are 8 bytes.
1014 When read on a box where Python ints are 4 bytes, such values are
1015 converted to Python longs.
1016
Tim Petersbdee63f2001-09-02 03:40:59 +00001017- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001018 code objects is no longer allowed. This plugs a security hole.
1019
Steve Purcell6091cd62001-09-06 16:05:17 +00001020- unittest.TestResult instances no longer store references to tracebacks
1021 generated by test failures. This prevents unexpected dangling references
1022 to objects that should be garbage collected between tests.
1023
Tim Petersedc99312001-08-22 21:36:50 +00001024Tools
1025
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001026- Tools/scripts/fixdiv.py has been added which can be used to fix
1027 division operators as per PEP 238.
1028
Tim Petersedc99312001-08-22 21:36:50 +00001029Build
1030
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001031- If you are an adventurous person using Mac OS X you may want to look at
1032 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1033 application, which can be used for experimenting with Carbon or Cocoa.
1034 Discussion of this on pythonmac-sig, please.
1035
Tim Peters7eea37e2001-09-04 22:08:56 +00001036C API
1037
1038- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001039
Tim Peters9fffa3e2001-09-04 05:14:19 +00001040- Note that PyLong_AsDouble can fail! This has always been true, but no
1041 callers checked for it. It's more likely to fail now, because overflow
1042 errors are properly detected now. The proper way to check:
1043
1044 double x = PyLong_AsDouble(some_long_object);
1045 if (x == -1.0 && PyErr_Occurred()) {
1046 /* The conversion failed. */
1047 }
1048
Tim Petersbdee63f2001-09-02 03:40:59 +00001049- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001050 compile but will not participate in GC. To upgrade an extension
1051 module:
1052
1053 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001054
Neil Schemenauer4042c692001-08-30 15:38:01 +00001055 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1056 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001057
Neil Schemenauer4042c692001-08-30 15:38:01 +00001058 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1059 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001060
Neil Schemenauer4042c692001-08-30 15:38:01 +00001061 - remove PyGC_HEAD_SIZE from object size calculations
1062
1063 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1064
Tim Petersbdee63f2001-09-02 03:40:59 +00001065- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001066 These can be used safely to construct string objects from a
1067 sprintf-style format string (similar to the format string supported
1068 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001069
Tim Petersedc99312001-08-22 21:36:50 +00001070New platforms
1071
Tim Petersb7da0902001-09-02 23:01:43 +00001072- Stephen Hansen contributed patches sufficient to get a clean compile
1073 under Borland C (Windows), but he reports problems running it and ran
1074 out of time to complete the port. Volunteers? Expect a MemoryError
1075 when importing the types module; this is probably shallow, and
1076 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001077
Tim Petersedc99312001-08-22 21:36:50 +00001078Tests
1079
1080Windows
1081
Tim Peters6e13a562001-09-06 00:32:15 +00001082- Large file support is now enabled on Win32 platforms as well as on
1083 Win64. This means that, for example, you can use f.tell() and f.seek()
1084 to manipulate files larger than 2 gigabytes (provided you have enough
1085 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001086 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1087 filesize limit, and large file support makes no difference there.
1088 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1089 NTFS has no practical limit on file size, and files of any size can be
1090 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001091
Tim Petersbdee63f2001-09-02 03:40:59 +00001092- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001093 points to command.com (patch from Brian Quinlan).
1094
Tim Petersedc99312001-08-22 21:36:50 +00001095
Tim Peters20f51a72001-07-21 02:31:40 +00001096What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001097Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001098===========================
1099
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001100Build
1101
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001102- Tim Peters developed a brand new Windows installer using Wise 8.1,
1103 generously donated to us by Wise Solutions.
1104
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001105- configure supports a new option --enable-unicode, with the values
1106 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1107 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001108
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001109- A new configure option --enable-framework builds a Mac OS X framework,
1110 which "make frameworkinstall" will install. This provides a starting
1111 point for more mac-like functionality, join pythonmac-sig@python.org
1112 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001113
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001114- The NeXT platform is no longer supported.
1115
1116- The `new' module is now statically linked.
1117
Tim Peters0afb6092001-08-15 06:06:44 +00001118Tools
1119
1120- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001121 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001122 the module docstring for details.
1123
Tim Peters20f51a72001-07-21 02:31:40 +00001124Tests
1125
Tim Peters5e824c32001-08-12 22:25:01 +00001126- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001127 platforms, allowing to give clearer test result output. regrtest
1128 also has optional --use/-u switch to run normally disabled tests
1129 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001130
Tim Peters20f51a72001-07-21 02:31:40 +00001131- Several new tests in the standard test suite, with special thanks to
1132 Nick Mathewson.
1133
1134Core
1135
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001136- The floor division operator // has been added as outlined in PEP
1137 238. The / operator still provides classic division (and will until
1138 Python 3.0) unless "from __future__ import division" is included, in
1139 which case the / operator will provide true division. The operator
1140 module provides truediv() and floordiv() functions. Augmented
1141 assignment variants are included, as are the equivalent overloadable
1142 methods and C API methods. See the PEP for a full discussion:
1143 <http://python.sf.net/peps/pep-0238.html>
1144
Tim Peters6cd6a822001-08-17 22:11:27 +00001145- Future statements are now effective in simulated interactive shells
1146 (like IDLE). This should "just work" by magic, but read Michael
1147 Hudson's "Future statements in simulated shells" PEP 264 for full
1148 details: <http://python.sf.net/peps/pep-0264.html>.
1149
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001150- The type/class unification (PEP 252-253) was integrated into the
1151 trunk and is not so tentative any more (the exact specification of
1152 some features is still tentative). A lot of work has done on fixing
1153 bugs and adding robustness and features (performance still has to
1154 come a long way).
1155
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001156- Warnings about a mismatch in the Python API during extension import
1157 now use the Python warning framework (which makes it possible to
1158 write filters for these warnings).
1159
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001160- A function's __dict__ (aka func_dict) will now always be a
1161 dictionary. It used to be possible to delete it or set it to None,
1162 but now both actions raise TypeErrors. It is still legal to set it
1163 to a dictionary object. Getting func.__dict__ before any attributes
1164 have been assigned now returns an empty dictionary instead of None.
1165
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001166- A new command line option, -E, was added which disables the use of
1167 all environment variables, or at least those that are specifically
1168 significant to Python. Usually those have a name starting with
1169 "PYTHON". This was used to fix a problem where the tests fail if
1170 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1171 older distribution.
1172
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001173Library
1174
Tim Peters5e824c32001-08-12 22:25:01 +00001175- New class Differ and new functions ndiff() and restore() in difflib.py.
1176 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001177 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001178
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001179- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1180 value using the minimal quoting required for the value; more
1181 reliable than using xml.sax.saxutils.escape() for attribute values.
1182
1183- Readline completion support for cmd.Cmd was added.
1184
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001185- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1186
1187- Added function threading.BoundedSemaphore()
1188
1189- Added Ka-Ping Yee's cgitb.py module.
1190
1191- The `new' module now exposes the CO_xxx flags.
1192
Martin v. Löwis560da622001-11-24 09:24:51 +00001193- The gc module offers the get_referents function.
1194
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001195New platforms
1196
1197C API
1198
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001199- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1200 which provide a cross-platform implementations for the
1201 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1202 the standard sprintf() and vsprintf() C lib APIs, these versions
1203 apply bounds checking on the used buffer which enhances protection
1204 against buffer overruns.
1205
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001206- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001207 and extensions using different Unicode widths is rendered next to
1208 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001209 will result in an ImportError. Unicode extensions writers must make
1210 sure to check the Unicode width compatibility in their extensions by
1211 using at least one of the mangled Unicode APIs in the extension.
1212
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001213- Two new flags METH_NOARGS and METH_O are available in method definition
1214 tables to simplify implementation of methods with no arguments and a
1215 single untyped argument. Calling such methods is more efficient than
1216 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1217 deprecated.
1218
Tim Petersc1731372001-08-04 08:12:36 +00001219Windows
1220
1221- "import module" now compiles module.pyw if it exists and nothing else
1222 relevant is found.
1223
Tim Peters20f51a72001-07-21 02:31:40 +00001224
Guido van Rossum55a78992001-07-17 17:22:32 +00001225What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001226Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001227===========================
1228
1229Core
Tim Petersa814db52001-05-14 07:05:58 +00001230
Tim Peters6d6c1a32001-08-02 04:15:00 +00001231- TENTATIVELY, a large amount of code implementing much of what's
1232 described in PEP 252 (Making Types Look More Like Classes) and PEP
1233 253 (Subtyping Built-in Types) was added. This will be released
1234 with Python 2.2a1. Documentation will be provided separately
1235 through http://www.python.org/2.2/. The purpose of releasing this
1236 with Python 2.2a1 is to test backwards compatibility. It is
1237 possible, though not likely, that a decision is made not to release
1238 this code as part of 2.2 final, if any serious backwards
1239 incompapatibilities are found during alpha testing that cannot be
1240 repaired.
1241
Guido van Rossum55a78992001-07-17 17:22:32 +00001242- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001243 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001244 more 'yield' statements. See PEP 255. Since this adds a new
1245 keyword to the language, this feature must be enabled by including a
1246 future statement: "from __future__ import generators" (see PEP 236).
1247 Generators will become a standard feature in a future release
1248 (probably 2.3). Without this future statement, 'yield' remains an
1249 ordinary identifier, but a warning is issued each time it is used.
1250 (These warnings currently don't conform to the warnings framework of
1251 PEP 230; we intend to fix this in 2.2a2.)
1252
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001253- The UTF-16 codec was modified to be more RFC compliant. It will now
1254 only remove BOM characters at the start of the string and then
1255 only if running in native mode (UTF-16-LE and -BE won't remove a
1256 leading BMO character).
1257
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001258- Strings now have a new method .decode() to complement the already
1259 existing .encode() method. These two methods provide direct access
1260 to the corresponding decoders and encoders of the registered codecs.
1261
1262 To enhance the usability of the .encode() method, the special
1263 casing of Unicode object return values was dropped (Unicode objects
1264 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001265
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001266 Both methods will now return whatever the codec in charge of the
1267 requested encoding returns as object, e.g. Unicode codecs will
1268 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1269 will return u"äöü"). This enables codec writer to create codecs
1270 for various simple to use conversions.
1271
1272 New codecs were added to demonstrate these new features (the .encode()
1273 and .decode() columns indicate the type of the returned objects):
1274
1275 Name | .encode() | .decode() | Description
1276 ----------------------------------------------------------------------
1277 uu | string | string | UU codec (e.g. for email)
1278 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001279 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001280 zlib | string | string | zlib compression
1281 hex | string | string | 2-byte hex codec
1282 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1283
Mark Hammond2a0af792001-05-14 03:09:36 +00001284- Some operating systems now support the concept of a default Unicode
1285 encoding for file system operations. Notably, Windows supports 'mbcs'
1286 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001287 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001288 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001289
1290 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001291 functions that return filenames (such as os.listdir()) to return Python
1292 string objects pre-encoded using the default file system encoding for
1293 the platform. As this encoding is likely to be different from Python's
1294 default encoding, converting this name to a Unicode object before passing
1295 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001296 would attempt to use its default encoding (generally ASCII) rather than
1297 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001298
Tim Petersa814db52001-05-14 07:05:58 +00001299 In general, this change simply removes surprises when working with
1300 Unicode and the file system, making these operations work as you expect,
1301 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001302 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001303
Tim Peters61dff2b2001-05-08 15:43:37 +00001304- Float (and complex) literals in source code were evaluated to full
1305 precision only when running from a .py file; the same code loaded from a
1306 .pyc (or .pyo) file could suffer numeric differences starting at about the
1307 12th significant decimal digit. For example, on a machine with IEEE-754
1308 floating arithmetic,
1309
1310 x = 9007199254740992.0
1311 print long(x)
1312
1313 printed 9007199254740992 if run directly from .py, but 9007199254740000
1314 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1315 str(float) instead of repr(float) when building code objects. marshal
1316 now uses repr(float) instead, which should reproduce floats to full
1317 machine precision (assuming the platform C float<->string I/O conversion
1318 functions are of good quality).
1319
1320 This may cause floating-point results to change in some cases, and
1321 usually for the better, but may also cause numerically unstable
1322 algorithms to break.
1323
Tim Peters2f228e72001-05-13 00:19:31 +00001324- The implementation of dicts suffers fewer collisions, which has speed
1325 benefits. However, the order in which dict entries appear in dict.keys(),
1326 dict.values() and dict.items() may differ from previous releases for a
1327 given dict. Nothing is defined about this order, so no program should
1328 rely on it. Nevertheless, it's easy to write test cases that rely on the
1329 order by accident, typically because of printing the str() or repr() of a
1330 dict to an "expected results" file. See Lib/test/test_support.py's new
1331 sortdict(dict) function for a simple way to display a dict in sorted
1332 order.
1333
Tim Peters7a3bfc32001-06-12 01:22:22 +00001334- Many other small changes to dicts were made, resulting in faster
1335 operation along the most common code paths.
1336
Guido van Rossum10315822001-05-01 20:54:30 +00001337- Dictionary objects now support the "in" operator: "x in dict" means
1338 the same as dict.has_key(x).
1339
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001340- The update() method of dictionaries now accepts generic mapping
1341 objects. Specifically the argument object must support the .keys()
1342 and __getitem__() methods. This allows you to say, for example,
1343 {}.update(UserDict())
1344
Guido van Rossum10315822001-05-01 20:54:30 +00001345- Iterators were added; this is a generalized way of providing values
1346 to a for loop. See PEP 234. There's a new built-in function iter()
1347 to return an iterator. There's a new protocol to get the next value
1348 from an iterator using the next() method (in Python) or the
1349 tp_iternext slot (in C). There's a new protocol to get iterators
1350 using the __iter__() method (in Python) or the tp_iter slot (in C).
1351 Iterating (i.e. a for loop) over a dictionary generates its keys.
1352 Iterating over a file generates its lines.
1353
Tim Petersf553f892001-05-01 20:45:31 +00001354- The following functions were generalized to work nicely with iterator
1355 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001356 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001357 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1358 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001359 join() method of strings
1360 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001361 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1362 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001363 right-hand side of assignment statements with multiple targets, such as
1364 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001365
Tim Petersd85e1022001-05-11 21:51:48 +00001366- Accessing module attributes is significantly faster (for example,
1367 random.random or os.path or yourPythonModule.yourAttribute).
1368
Tim Peterse63415e2001-05-08 04:38:29 +00001369- Comparing dictionary objects via == and != is faster, and now works even
1370 if the keys and values don't support comparisons other than ==.
1371
Tim Peters95bf9392001-05-10 08:32:44 +00001372- Comparing dictionaries in ways other than == and != is slower: there were
1373 insecurities in the dict comparison implementation that could cause Python
1374 to crash if the element comparison routines for the dict keys and/or
1375 values mutated the dicts. Making the code bulletproof slowed it down.
1376
Tim Peterseb28ef22001-06-02 05:27:19 +00001377- Collisions in dicts are resolved via a new approach, which can help
1378 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001379 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001380 faster now. Thanks to Christian Tismer for pointing out the cause and
1381 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001382
Tim Peters52e155e2001-06-16 05:42:57 +00001383- repr() is much faster for large containers (dict, list, tuple).
1384
1385
Tim Petersa814db52001-05-14 07:05:58 +00001386Library
1387
Fred Drake960fdf92001-07-20 18:38:26 +00001388- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1389 were added to the string module. These a locale-indenpendent
1390 constants, unlike letters, lowercase, and uppercase. These are now
1391 use in appropriate locations in the standard library.
1392
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001393- The flags used in dlopen calls can now be configured using
1394 sys.setdlopenflags and queried using sys.getdlopenflags.
1395
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001396- Fredrik Lundh's xmlrpclib is now a standard library module. This
1397 provides full client-side XML-RPC support. In addition,
1398 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1399 one asyncore-based). Thanks to Eric Raymond for the documentation.
1400
Guido van Rossum643d3912001-07-05 14:46:25 +00001401- The xrange() object is simplified: it no longer supports slicing,
1402 repetition, comparisons, efficient 'in' checking, the tolist()
1403 method, or the start, stop and step attributes. See PEP 260.
1404
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001405- A new function fnmatch.filter to filter lists of file names was added.
1406
Barry Warsawffd674d2001-05-22 16:00:10 +00001407- calendar.py uses month and day names based on the current locale.
1408
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001409- strop is now *really* obsolete (this was announced before with 1.6),
1410 and issues DeprecationWarning when used (except for the four items
1411 that are still imported into string.py).
1412
Tim Petersa814db52001-05-14 07:05:58 +00001413- Cookie.py now sorts key+value pairs by key in output strings.
1414
1415- pprint.isrecursive(object) didn't correctly identify recursive objects.
1416 Now it does.
1417
Tim Peters95b3f782001-05-14 18:39:41 +00001418- pprint functions now much faster for large containers (tuple, list, dict).
1419
Tim Peters7b9542a2001-06-10 23:40:19 +00001420- New 'q' and 'Q' format codes in the struct module, corresponding to C
1421 types "long long" and "unsigned long long" (on Windows, __int64). In
1422 native mode, these can be used only when the platform C compiler supports
1423 these types (when HAVE_LONG_LONG is #define'd by the Python config
1424 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001425 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1426 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001427
Guido van Rossum83213cc2001-06-12 16:48:52 +00001428- The site module installs a new built-in function 'help' that invokes
1429 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1430 it displays a message reminding the user to use 'help()' or
1431 'help(object)'.
1432
Tim Petersa814db52001-05-14 07:05:58 +00001433Tests
1434
1435- New test_mutants.py runs dict comparisons where the key and value
1436 comparison operators mutute the dicts randomly during comparison. This
1437 rapidly causes Python to crash under earlier releases (not for the faint
1438 of heart: it can also cause Win9x to freeze or reboot!).
1439
1440- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001441 pprint.isreadable() return sensible results. Also verifies that simple
1442 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001443
Tim Peters4324aa32001-05-28 22:30:08 +00001444C API
1445
1446- Removed the unused last_is_sticky argument from the internal
1447 _PyTuple_Resize(). If this affects you, you were cheating.
1448
1449
Guido van Rossum55a78992001-07-17 17:22:32 +00001450======================================================================
1451
1452
Guido van Rossumffe13be2001-04-16 18:46:45 +00001453What's New in Python 2.1 (final)?
1454=================================
1455
1456We only changed a few things since the last release candidate, all in
1457Python library code:
1458
1459- A bug in the locale module was fixed that affected locales which
1460 define no grouping for numeric formatting.
1461
1462- A few bugs in the weakref module's implementations of weak
1463 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1464 and the test suite was updated to check for these bugs.
1465
1466- An old bug in the os.path.walk() function (introduced in Python
1467 2.0!) was fixed: a non-existent file would cause an exception
1468 instead of being ignored.
1469
1470- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1471 PyChecker.
1472
1473
Guido van Rossum5b08f132001-04-16 02:05:23 +00001474What's New in Python 2.1c2?
1475===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001476
Guido van Rossum5b08f132001-04-16 02:05:23 +00001477A flurry of small changes, and one showstopper fixed in the nick of
1478time made it necessary to release another release candidate. The list
1479here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001480
Guido van Rossum5b08f132001-04-16 02:05:23 +00001481Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001482
Guido van Rossum5b08f132001-04-16 02:05:23 +00001483- Tim discovered a nasty bug in the dictionary code, caused by
1484 PyDict_Next() calling dict_resize(), and the GC code's use of
1485 PyDict_Next() violating an assumption in dict_items(). This was
1486 fixed with considerable amounts of band-aid, but the net effect is a
1487 saner and more robust implementation.
1488
1489- Made a bunch of symbols static that were accidentally global.
1490
1491Build and Ports
1492
1493- The setup.py script didn't check for a new enough version of zlib
1494 (1.1.3 is needed). Now it does.
1495
1496- Changed "make clean" target to also remove shared libraries.
1497
1498- Added a more general warning about the SGI Irix optimizer to README.
1499
1500Library
1501
1502- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1503 omitted the slash between host and file.html.
1504
1505- The mailbox module's _Mailbox class contained a completely broken
1506 and undocumented seek() method. Ripped it out.
1507
1508- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1509 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1510
1511- Fixed a few last-minute bugs in unittest.
1512
1513Extensions
1514
1515- Reverted the patch to the OpenSSL code in socketmodule.c to support
1516 RAND_status() and the EGD, and the subsequent patch that tried to
1517 fix it for pre-0.9.5 versions; the problem with the patch is that on
1518 some systems it issues a warning whenever socket is imported, and
1519 that's unacceptable.
1520
1521Tests
1522
1523- Fixed the pickle tests to work with "import test.test_pickle".
1524
1525- Tweaked test_locale.py to actually run the test Windows.
1526
1527- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1528 not "wb" (which is not a valid mode at all).
1529
1530- Fix pstats browser crashes. Import readline if it exists to make
1531 the user interface nicer.
1532
1533- Add "import thread" to the top of test modules that import the
1534 threading module (test_asynchat and test_threadedtempfile). This
1535 prevents test failures caused by a broken threading module resulting
1536 from a previously caught failed import.
1537
1538- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1539 needed on some platforms (e.g. Solaris 8) when the tests are run
1540 twice in succession.
1541
1542- Skip rather than fail test_sunaudiodev if no audio device is found.
1543
1544
1545What's New in Python 2.1c1?
1546===========================
1547
1548This list was significantly updated when 2.1c2 was released; the 2.1c1
1549release didn't mention most changes that were actually part of 2.1c1:
1550
1551Legal
1552
1553- Copyright was assigned to the Python Software Foundation (PSF) and a
1554 PSF license (very similar to the CNRI license) was added.
1555
1556- The CNRI copyright notice was updated to include 2001.
1557
1558Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001559
Guido van Rossumc9932722001-04-12 02:31:27 +00001560- After a public outcry, assignment to __debug__ is no longer illegal;
1561 instead, a warning is issued. It will become illegal in 2.2.
1562
Guido van Rossum5b08f132001-04-16 02:05:23 +00001563- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1564 "%#x" now always prepends "0x", even if the value is zero.
1565
1566- Fixed some nits in the bytecode compiler.
1567
1568- Fixed core dumps when calling certain kinds of non-functions.
1569
1570- Fixed various core dumps caused by reference count bugs.
1571
1572Build and Ports
1573
1574- Use INSTALL_SCRIPT to install script files.
1575
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001576- New port: SCO Unixware 7, by Billy G. Allie.
1577
Guido van Rossum5b08f132001-04-16 02:05:23 +00001578- Updated RISCOS port.
1579
1580- Updated BeOS port and notes.
1581
1582- Various other porting problems resolved.
1583
1584Library
1585
1586- The TERMIOS and SOCKET modules are now truly obsolete and
1587 unnecessary. Their symbols are incorporated in the termios and
1588 socket modules.
1589
1590- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1591 better tests for pickling.
1592
1593- threading: make Condition.wait() robust against KeyboardInterrupt.
1594
1595- zipfile: add support to zipfile to support opening an archive
1596 represented by an open file rather than a file name. Fix bug where
1597 the archive was not properly closed. Fixed a bug in this bugfix
1598 where flush() was called for a read-only file.
1599
1600- imputil: added an uninstall() method to the ImportManager.
1601
1602- Canvas: fixed bugs in lower() and tkraise() methods.
1603
1604- SocketServer: API change (added overridable close_request() method)
1605 so that the TCP server can explicitly close the request.
1606
1607- pstats: Eric Raymond added a simple interactive statistics browser,
1608 invoked when the module is run as a script.
1609
1610- locale: fixed a problem in format().
1611
1612- webbrowser: made it work when the BROWSER environment variable has a
1613 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1614 KDE 2. Fixed some other nits.
1615
1616- unittest: changes to allow using a different exception than
1617 AssertionError, and added a few more function aliases. Some other
1618 small changes.
1619
1620- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1621
1622- asynchat: fixed a critical bug in asynchat that slipped through the
1623 2.1b2 release. Fixed another rare bug.
1624
1625- Fix some unqualified except: clauses (always a bad code example).
1626
1627XML
1628
1629- pyexpat: new API get_version_string().
1630
1631- Fixed some minidom bugs.
1632
1633Extensions
1634
1635- Fixed a core dump in _weakref. Removed the weakref.mapping()
1636 function (it adds nothing to the API).
1637
1638- Rationalized the use of header files in the readline module, to make
1639 it compile (albeit with some warnings) with the very recent readline
1640 4.2, without breaking for earlier versions.
1641
1642- Hopefully fixed a buffering problem in linuxaudiodev.
1643
1644- Attempted a fix to make the OpenSSL support in the socket module
1645 work again with pre-0.9.5 versions of OpenSSL.
1646
1647Tests
1648
1649- Added a test case for asynchat and asyncore.
1650
1651- Removed coupling between tests where one test failing could break
1652 another.
1653
1654Tools
1655
1656- Ping added an interactive help browser to pydoc, fixed some nits
1657 in the rest of the pydoc code, and added some features to his
1658 inspect module.
1659
1660- An updated python-mode.el version 4.1 which integrates Ken
1661 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1662 much nicer in XEmacs and Emacs. When stepping through your program
1663 with pdb, in either the shell window or the *Python* window, the
1664 source file and line will be tracked by an arrow. Very cool!
1665
1666- IDLE: syntax warnings in interactive mode are changed into errors.
1667
1668- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001669 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001670
1671- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001672
Barry Warsaw11e89c72001-04-11 20:37:57 +00001673
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001674What's New in Python 2.1 beta 2?
1675================================
1676
Guido van Rossum053ae352001-03-22 14:17:21 +00001677(Unlisted are many fixed bugs, more documentation, etc.)
1678
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001679Core language, builtins, and interpreter
1680
Guido van Rossum053ae352001-03-22 14:17:21 +00001681- The nested scopes work (enabled by "from __future__ import
1682 nested_scopes") is completed; in particular, the future now extends
1683 into code executed through exec, eval() and execfile(), and into the
1684 interactive interpreter.
1685
1686- When calling a base class method (e.g. BaseClass.__init__(self)),
1687 this is now allowed even if self is not strictly spoken a class
1688 instance (e.g. when using metaclasses or the Don Beaudry hook).
1689
1690- Slice objects are now comparable but not hashable; this prevents
1691 dict[:] from being accepted but meaningless.
1692
1693- Complex division is now calculated using less braindead algorithms.
1694 This doesn't change semantics except it's more likely to give useful
1695 results in extreme cases. Complex repr() now uses full precision
1696 like float repr().
1697
1698- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1699
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001700- It is illegal to assign to the name __debug__, which is set when the
1701 interpreter starts. It is effectively a compile-time constant.
1702
1703- A warning will be issued if a global statement for a variable
1704 follows a use or assignment of that variable.
1705
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001706Standard library
1707
Guido van Rossum053ae352001-03-22 14:17:21 +00001708- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1709 inspired by JUnit), is now part of the standard library. You now
1710 have a choice of two testing frameworks: unittest requires you to
1711 write testcases as separate code, doctest gathers them from
1712 docstrings. Both approaches have their advantages and
1713 disadvantages.
1714
1715- A new module Tix was added, which wraps the Tix extension library
1716 for Tk. With that module, it is not necessary to statically link
1717 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1718 require" command. See Demo/tix/.
1719
1720- tzparse.py is now obsolete.
1721
1722- In gzip.py, the seek() and tell() methods are removed -- they were
1723 non-functional anyway, and it's better if callers can test for their
1724 existence with hasattr().
1725
1726Python/C API
1727
1728- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1729 that's already in the dictionary during a PyDict_Next() iteration.
1730 This used to fail occasionally when a dictionary resize operation
1731 could be triggered that would rehash all the keys. All other
1732 modifications to the dictionary are still off-limits during a
1733 PyDict_Next() iteration!
1734
1735- New extended APIs related to passing compiler variables around.
1736
1737- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1738 implement isinstance() and issubclass().
1739
1740- Py_BuildValue() now has a "D" conversion to create a Python complex
1741 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001742
Fred Drake4e262a92001-03-22 18:26:47 +00001743- Extensions types which support weak references must now set the
1744 field allocated for the weak reference machinery to NULL themselves;
1745 this is done to avoid the cost of checking each object for having a
1746 weakly referencable type in PyObject_INIT(), since most types are
1747 not weakly referencable.
1748
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001749- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1750 free variables and cell variables to and from the frame's f_locals.
1751
1752- Variants of several functions defined in pythonrun.h have been added
1753 to support the nested_scopes future statement. The variants all end
1754 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1755 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1756 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001757 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001758
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001759Distutils
1760
1761- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1762 into the release tree.
1763
Tim Peters0e57abf2001-05-02 07:39:38 +00001764- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001765 (an uninstaller, more customization of the installer's display)
1766
1767- from Jack Jansen: added Mac-specific code to generate a dialog for
1768 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001769 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001770 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001771
1772- added 'platforms' and 'keywords' to the set of metadata that can be
1773 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001774
1775- applied patches from Jason Tishler to make the compiler class work with
1776 Cygwin.
1777
1778
Tim Peters2fe289a2001-03-01 22:19:38 +00001779What's New in Python 2.1 beta 1?
1780================================
Tim Petersd66595f2001-02-04 03:09:53 +00001781
1782Core language, builtins, and interpreter
1783
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001784- Following an outcry from the community about the amount of code
1785 broken by the nested scopes feature introduced in 2.1a2, we decided
1786 to make this feature optional, and to wait until Python 2.2 (or at
1787 least 6 months) to make it standard. The option can be enabled on a
1788 per-module basis by adding "from __future__ import nested_scopes" at
1789 the beginning of a module (before any other statements, but after
1790 comments and an optional docstring). See PEP 236 (Back to the
1791 __future__) for a description of the __future__ statement. PEP 227
1792 (Statically Nested Scopes) has been updated to reflect this change,
1793 and to clarify the semantics in a number of endcases.
1794
1795- The nested scopes code, when enabled, has been hardened, and most
1796 bugs and memory leaks in it have been fixed.
1797
1798- Compile-time warnings are now generated for a number of conditions
1799 that will break or change in meaning when nested scopes are enabled:
1800
1801 - Using "from...import *" or "exec" without in-clause in a function
1802 scope that also defines a lambda or nested function with one or
1803 more free (non-local) variables. The presence of the import* or
1804 bare exec makes it impossible for the compiler to determine the
1805 exact set of local variables in the outer scope, which makes it
1806 impossible to determine the bindings for free variables in the
1807 inner scope. To avoid the warning about import *, change it into
1808 an import of explicitly name object, or move the import* statement
1809 to the global scope; to avoid the warning about bare exec, use
1810 exec...in... (a good idea anyway -- there's a possibility that
1811 bare exec will be deprecated in the future).
1812
1813 - Use of a global variable in a nested scope with the same name as a
1814 local variable in a surrounding scope. This will change in
1815 meaning with nested scopes: the name in the inner scope will
1816 reference the variable in the outer scope rather than the global
1817 of the same name. To avoid the warning, either rename the outer
1818 variable, or use a global statement in the inner function.
1819
Neil Schemenauera35c6882001-02-27 04:45:05 +00001820- An optional object allocator has been included. This allocator is
1821 optimized for Python objects and should be faster and use less memory
1822 than the standard system allocator. It is not enabled by default
1823 because of possible thread safety problems. The allocator is only
1824 protected by the Python interpreter lock and it is possible that some
1825 extension modules require a thread safe allocator. The object
1826 allocator can be enabled by providing the "--with-pymalloc" option to
1827 configure.
1828
Tim Petersd66595f2001-02-04 03:09:53 +00001829Standard library
1830
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001831- pyexpat now detects the expat version if expat.h defines it. A
1832 number of additional handlers are provided, which are only available
1833 since expat 1.95. In addition, the methods SetParamEntityParsing and
1834 GetInputContext of Parser objects are available with 1.95.x
1835 only. Parser objects now provide the ordered_attributes and
1836 specified_attributes attributes. A new module expat.model was added,
1837 which offers a number of additional constants if 1.95.x is used.
1838
1839- xml.dom offers the new functions registerDOMImplementation and
1840 getDOMImplementation.
1841
1842- xml.dom.minidom offers a toprettyxml method. A number of DOM
1843 conformance issues have been resolved. In particular, Element now
1844 has an hasAttributes method, and the handling of namespaces was
1845 improved.
1846
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001847- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1848 getting information about live Python code, and pydoc.py, a module
1849 for interactively converting docstrings to HTML or text.
1850 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001851 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001852 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1853 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001854
Tim Peters1eff7962001-03-01 02:31:33 +00001855- New library module difflib.py, primarily packaging the SequenceMatcher
1856 class at the heart of the popular ndiff.py file-comparison tool.
1857
1858- doctest.py (a framework for verifying Python code examples in docstrings)
1859 is now part of the std library.
1860
Tim Petersd66595f2001-02-04 03:09:53 +00001861Windows changes
1862
Guido van Rossume3955a82001-03-02 14:05:59 +00001863- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1864 small GUI that lets you browse the module docstrings using your
1865 default web browser.
1866
Tim Peters1eff7962001-03-01 02:31:33 +00001867- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1868 Platforms) is implemented. See
1869
1870 http://python.sourceforge.net/peps/pep-0235.html
1871
1872 for full details, especially the "Current Lower-Left Semantics" section.
1873 The new Windows import rules are simpler than before:
1874
1875 A. If the PYTHONCASEOK environment variable exists, same as
1876 before: silently accept the first case-insensitive match of any
1877 kind; raise ImportError if none found.
1878
1879 B. Else search sys.path for the first case-sensitive match; raise
1880 ImportError if none found.
1881
1882 The same rules have been implented on other platforms with case-
1883 insensitive but case-preserving filesystems too (including Cygwin, and
1884 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001885
Tim Peters25a9ce32001-02-19 07:06:36 +00001886- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1887 what it's supposed to do (and does do under NT and 2000) via direct
1888 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001889 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001890 all Win9x systems before.
1891
Tim Peters1eff7962001-03-01 02:31:33 +00001892- Build: Subproject _test (effectively) renamed to _testcapi.
1893
Tim Peters2fe289a2001-03-01 22:19:38 +00001894New platforms
1895
1896- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1897 Thanks to Steven Majewski!
1898
1899- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1900 Tishler!
1901
Guido van Rossum9089b272001-03-02 06:49:50 +00001902- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1903 Schwertberger! See RISCOS/README for more information -- it seems
1904 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001905 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001906
Tim Peters25a9ce32001-02-19 07:06:36 +00001907
Tim Petersd7b5e882001-01-25 03:36:26 +00001908What's New in Python 2.1 alpha 2?
1909=================================
Tim Peters40ead762001-01-27 05:35:26 +00001910
Tim Petersd7b5e882001-01-25 03:36:26 +00001911Core language, builtins, and interpreter
1912
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001913- Scopes nest. If a name is used in a function or class, but is not
1914 local, the definition in the nearest enclosing function scope will
1915 be used. One consequence of this change is that lambda statements
1916 could reference variables in the namespaces where the lambda is
1917 defined. In some unusual cases, this change will break code.
1918
1919 In all previous version of Python, names were resolved in exactly
1920 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001921 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001922 function A is defined within a function B, the names bound in B are
1923 not visible in A. The new rules make names bound in B visible in A,
1924 unless A contains a name binding that hides the binding in B.
1925
1926 Section 4.1 of the reference manual describes the new scoping rules
1927 in detail. The test script in Lib/test/test_scope.py demonstrates
1928 some of the effects of the change.
1929
1930 The new rules will cause existing code to break if it defines nested
1931 functions where an outer function has local variables with the same
1932 name as globals or builtins used by the inner function. Example:
1933
1934 def munge(str):
1935 def helper(x):
1936 return str(x)
1937 if type(str) != type(''):
1938 str = helper(str)
1939 return str.strip()
1940
1941 Under the old rules, the name str in helper() is bound to the
1942 builtin function str(). Under the new rules, it will be bound to
1943 the argument named str and an error will occur when helper() is
1944 called.
1945
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001946- The compiler will report a SyntaxError if "from ... import *" occurs
1947 in a function or class scope. The language reference has documented
1948 that this case is illegal, but the compiler never checked for it.
1949 The recent introduction of nested scope makes the meaning of this
1950 form of name binding ambiguous. In a future release, the compiler
1951 may allow this form when there is no possibility of ambiguity.
1952
Tim Peters40ead762001-01-27 05:35:26 +00001953- repr(string) is easier to read, now using hex escapes instead of octal,
1954 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1955
1956 >>> "\texample \r\n" + chr(0) + chr(255)
1957 '\texample \r\n\x00\xff' # in 2.1
1958 '\011example \015\012\000\377' # in 2.0
1959
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001960- Functions are now compared and hashed by identity, not by value, since
1961 the func_code attribute is writable.
1962
Fred Drakefb9d7122001-02-01 20:00:40 +00001963- Weak references (PEP 205) have been added. This involves a few
1964 changes in the core, an extension module (_weakref), and a Python
1965 module (weakref). The weakref module is the public interface. It
1966 includes support for "explicit" weak references, proxy objects, and
1967 mappings with weakly held values.
1968
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001969- A 'continue' statement can now appear in a try block within the body
1970 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001971 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001972
Tim Petersd7b5e882001-01-25 03:36:26 +00001973Standard library
1974
Barry Warsaw30dbd142001-01-31 22:14:01 +00001975- mailbox.py now has a new class, PortableUnixMailbox which is
1976 identical to UnixMailbox but uses a more portable scheme for
1977 determining From_ separators. Also, the constructors for all the
1978 classes in this module have a new optional `factory' argument, which
1979 is a callable used when new message classes must be instantiated by
1980 the next() method.
1981
Tim Petersd7b5e882001-01-25 03:36:26 +00001982- random.py is now self-contained, and offers all the functionality of
1983 the now-deprecated whrandom.py. See the docs for details. random.py
1984 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001985 and restoring the internal state of the generator; and jumpahead(n),
1986 for quickly forcing the internal state to be the same as if n calls to
1987 random() had been made. The latter is particularly useful for multi-
1988 threaded programs, creating one instance of the random.Random() class for
1989 each thread, then using .jumpahead() to force each instance to use a
1990 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001991
Tim Peters0de88fc2001-02-01 04:59:18 +00001992- random.py's seed() function is new. For bit-for-bit compatibility with
1993 prior releases, use the whseed function instead. The new seed function
1994 addresses two problems: (1) The old function couldn't produce more than
1995 about 2**24 distinct internal states; the new one about 2**45 (the best
1996 that can be done in the Wichmann-Hill generator). (2) The old function
1997 sometimes produced identical internal states when passed distinct
1998 integers, and there was no simple way to predict when that would happen;
1999 the new one guarantees to produce distinct internal states for all
2000 arguments in [0, 27814431486576L).
2001
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002002- The socket module now supports raw packets on Linux. The socket
2003 family is AF_PACKET.
2004
Tim Peters9ea17ac2001-02-02 05:57:15 +00002005- test_capi.py is a start at running tests of the Python C API. The tests
2006 are implemented by the new Modules/_testmodule.c.
2007
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002008- A new extension module, _symtable, provides provisional access to the
2009 internal symbol table used by the Python compiler. A higher-level
2010 interface will be added on top of _symtable in a future release.
2011
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002012- Removed the obsolete soundex module.
2013
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002014- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2015 the isSameNode method; NamedNodeMap the get method.
2016
2017- xml.sax.expatreader supports the lexical handler property; it
2018 generates comment, startCDATA, and endCDATA events.
2019
Tim Petersee826f82001-01-31 19:39:44 +00002020Windows changes
2021
2022- Build procedure: the zlib project is built in a different way that
2023 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002024 the zlib binary used. See PCbuild\readme.txt for details. Your old
2025 zlib-related directories can be deleted; you'll need to download fresh
2026 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002027
Tim Peters9ea17ac2001-02-02 05:57:15 +00002028- Build: New subproject _test for the benefit of test_capi.py (see above).
2029
Tim Petersb16c56f2001-02-02 21:24:51 +00002030- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2031 interface to some Python compiler internals).
2032
2033- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002034 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002035
Tim Petersa3a3a032000-11-30 05:22:44 +00002036What's New in Python 2.1 alpha 1?
2037=================================
2038
2039Core language, builtins, and interpreter
2040
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002041- There is a new Unicode companion to the PyObject_Str() API
2042 called PyObject_Unicode(). It behaves in the same way as the
2043 former, but assures that the returned value is an Unicode object
2044 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002045
Guido van Rossumf98eda02001-01-17 15:54:45 +00002046- The comparison operators support "rich comparison overloading" (PEP
2047 207). C extension types can provide a rich comparison function in
2048 the new tp_richcompare slot in the type object. The cmp() function
2049 and the C function PyObject_Compare() first try the new rich
2050 comparison operators before trying the old 3-way comparison. There
2051 is also a new C API PyObject_RichCompare() (which also falls back on
2052 the old 3-way comparison, but does not constrain the outcome of the
2053 rich comparison to a Boolean result).
2054
2055 The rich comparison function takes two objects (at least one of
2056 which is guaranteed to have the type that provided the function) and
2057 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2058 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2059 object, which may be NotImplemented (in which case the tp_compare
2060 slot function is used as a fallback, if defined).
2061
2062 Classes can overload individual comparison operators by defining one
2063 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002064 __ge__. There are no explicit "reflected argument" versions of
2065 these; instead, __lt__ and __gt__ are each other's reflection,
2066 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2067 reflection (similar at the C level). No other implications are
2068 made; in particular, Python does not assume that == is the Boolean
2069 inverse of !=, or that < is the Boolean inverse of >=. This makes
2070 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002071
2072 Classes or types that want to implement (in)equality tests but not
2073 the ordering operators (i.e. unordered types) should implement ==
2074 and !=, and raise an error for the ordering operators.
2075
Guido van Rossuma88479f2001-01-18 14:28:08 +00002076 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002077 Boolean; e.g. a matrix type might want to return a matrix of bits
2078 for A < B, giving elementwise comparisons. Such types should ensure
2079 that any interpretation of their value in a Boolean context raises
2080 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2081 at the C level) to always raise an exception.
2082
Guido van Rossuma88479f2001-01-18 14:28:08 +00002083- Complex numbers use rich comparisons to define == and != but raise
2084 an exception for <, <=, > and >=. Unfortunately, this also means
2085 that cmp() of two complex numbers raises an exception when the two
2086 numbers differ. Since it is not mathematically meaningful to compare
2087 complex numbers except for equality, I hope that this doesn't break
2088 too much code.
2089
Tim Peters3389f192001-02-18 08:48:49 +00002090- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002091 not defined by the language, other than that it's arbitrary but
2092 consistent (see the Reference Manual). An implementation detail changed
2093 in 2.1a1 such that None now compares less than any other object. Code
2094 relying on this new behavior (like code that relied on the previous
2095 behavior) does so at its own risk.
2096
Barry Warsaw573b5412001-01-15 20:43:18 +00002097- Functions and methods now support getting and setting arbitrarily
2098 named attributes (PEP 232). Functions have a new __dict__
2099 (a.k.a. func_dict) which hold the function attributes. Methods get
2100 and set attributes on their underlying im_func. It is a TypeError
2101 to set an attribute on a bound method.
2102
Guido van Rossum051e3352001-01-15 19:11:10 +00002103- The xrange() object implementation has been improved so that
2104 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2105 limitation that in this case len(xrange(sys.maxint)) can't be
2106 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2107 work fine as long as the index i doesn't actually reach 2**31.
2108 (Python uses regular ints for sequence and string indices; fixing
2109 that is much more work.)
2110
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002111- Two changes to from...import:
2112
Guido van Rossumba381232001-02-03 15:06:40 +00002113 1) "from M import X" now works even if (after loading module M)
2114 sys.modules['M'] is not a real module; it's basically a getattr()
2115 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002116
2117 2) "from M import *" now looks for M.__all__ to decide which names to
2118 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2119 filters out names starting with '_' as before. Whether or not
2120 __all__ exists, there's no restriction on the type of M.
2121
Guido van Rossumf61f1662001-01-10 20:13:55 +00002122- File objects have a new method, xreadlines(). This is the fastest
2123 way to iterate over all lines in a file:
2124
2125 for line in file.xreadlines():
2126 ...do something to line...
2127
2128 See the xreadlines module (mentioned below) for how to do this for
2129 other file-like objects.
2130
2131- Even if you don't use file.xreadlines(), you may expect a speedup on
2132 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002133 quite a bit in platform-specific ways: on systems (like Linux) that
2134 support flockfile(), getc_unlocked(), and funlockfile(), those are
2135 used by default. On systems (like Windows) without getc_unlocked(),
2136 a complicated (but still thread-safe) method using fgets() is used by
2137 default.
2138
Tim Petersd52269b2001-01-25 06:23:18 +00002139 You can force use of the fgets() method by #define'ing
2140 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002141 getc_unlocked()).
2142
Tim Petersd52269b2001-01-25 06:23:18 +00002143 You can force fgets() not to be used by #define'ing
2144 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002145 test_bufio.py fails -- and let us know if it does!).
2146
2147- In addition, the fileinput module, while still slower than the other
2148 methods on most platforms, has been sped up too, by using
2149 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002150
2151- Support for run-time warnings has been added, including a new
2152 command line option (-W) to specify the disposition of warnings.
2153 See the description of the warnings module below.
2154
2155- Extensive changes have been made to the coercion code. This mostly
2156 affects extension modules (which can now implement mixed-type
2157 numerical operators without having to use coercion), but
2158 occasionally, in boundary cases the coercion semantics have changed
2159 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002160 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002161 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002162 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002163
Guido van Rossumf98eda02001-01-17 15:54:45 +00002164- In connection with the coercion changes, a new built-in singleton
2165 object, NotImplemented is defined. This can be returned for
2166 operations that wish to indicate they are not implemented for a
2167 particular combination of arguments. From C, this is
2168 Py_NotImplemented.
2169
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002170- The interpreter accepts now bytecode files on the command line even
2171 if they do not have a .pyc or .pyo extension. On Linux, after executing
2172
Martin v. Löwise214baa2001-02-04 22:37:56 +00002173import imp,sys,string
2174magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2175reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2176open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002177
2178 any byte code file can be used as an executable (i.e. as an argument
2179 to execve(2)).
2180
Tim Peters9940b802000-12-01 07:59:35 +00002181- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002182 character. In 1.6 and earlier, they never produced a sign,
2183 and raised an error if the value of the long was too large
2184 to fit in a Python int. In 2.0, they produced a sign if and
2185 only if too large to fit in an int. This was inconsistent
2186 across platforms (because the size of an int varies across
2187 platforms), and inconsistent with hex() and oct(). Example:
2188
2189 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002190 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002191 'ffffffbe' # in 2.0 and before, on 32-bit machines
2192 >>> hex(-0x42L)
2193 '-0x42L' # in all versions of Python
2194
Tim Peters9940b802000-12-01 07:59:35 +00002195 The behavior of %d formats for negative Python longs remains
2196 the same as in 2.0 (although in 1.6 and before, they raised
2197 an error if the long didn't fit in a Python int).
2198
2199 %u formats don't make sense for Python longs, but are allowed
2200 and treated the same as %d in 2.1. In 2.0, a negative long
2201 formatted via %u produced a sign if and only if too large to
2202 fit in an int. In 1.6 and earlier, a negative long formatted
2203 via %u raised an error if it was too big to fit in an int.
2204
Guido van Rossum3661d392000-12-12 22:10:31 +00002205- Dictionary objects have an odd new method, popitem(). This removes
2206 an arbitrary item from the dictionary and returns it (in the form of
2207 a (key, value) pair). This can be useful for algorithms that use a
2208 dictionary as a bag of "to do" items and repeatedly need to pick one
2209 item. Such algorithms normally end up running in quadratic time;
2210 using popitem() they can usually be made to run in linear time.
2211
Tim Peters36cdad12000-12-29 02:06:45 +00002212Standard library
2213
Thomas Woutersfe385252001-01-19 23:16:56 +00002214- In the time module, the time argument to the functions strftime,
2215 localtime, gmtime, asctime and ctime is now optional, defaulting to
2216 the current time (in the local timezone).
2217
Guido van Rossumda91f222001-01-15 16:36:08 +00002218- The ftplib module now defaults to passive mode, which is deemed a
2219 more useful default given that clients are often inside firewalls
2220 these days. Note that this could break if ftplib is used to connect
2221 to a *server* that is inside a firewall, from outside; this is
2222 expected to be a very rare situation. To fix that, you can call
2223 ftp.set_pasv(0).
2224
Martin v. Löwis10a27872001-01-13 09:54:41 +00002225- The module site now treats .pth files not only for path configuration,
2226 but also supports extensions to the initialization code: Lines starting
2227 with import are executed.
2228
Guido van Rossumf61f1662001-01-10 20:13:55 +00002229- There's a new module, warnings, which implements a mechanism for
2230 issuing and filtering warnings. There are some new built-in
2231 exceptions that serve as warning categories, and a new command line
2232 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2233 turns warnings into errors). warnings.warn(message[, category])
2234 issues a warning message; this can also be called from C as
2235 PyErr_Warn(category, message).
2236
2237- A new module xreadlines was added. This exports a single factory
2238 function, xreadlines(). The intention is that this code is the
2239 absolutely fastest way to iterate over all lines in an open
2240 file(-like) object:
2241
2242 import xreadlines
2243 for line in xreadlines.xreadlines(file):
2244 ...do something to line...
2245
2246 This is equivalent to the previous the speed record holder using
2247 file.readlines(sizehint). Note that if file is a real file object
2248 (as opposed to a file-like object), this is equivalent:
2249
2250 for line in file.xreadlines():
2251 ...do something to line...
2252
Tim Peters36cdad12000-12-29 02:06:45 +00002253- The bisect module has new functions bisect_left, insort_left,
2254 bisect_right and insort_right. The old names bisect and insort
2255 are now aliases for bisect_right and insort_right. XXX_right
2256 and XXX_left methods differ in what happens when the new element
2257 compares equal to one or more elements already in the list: the
2258 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002259 right. Code that doesn't care where equal elements end up should
2260 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002261
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002262- The new curses.panel module wraps the panel library that forms part
2263 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2264
Guido van Rossumf61f1662001-01-10 20:13:55 +00002265- The SocketServer module now sets the allow_reuse_address flag by
2266 default in the TCPServer class.
2267
2268- A new function, sys._getframe(), returns the stack frame pointer of
2269 the caller. This is intended only as a building block for
2270 higher-level mechanisms such as string interpolation.
2271
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002272- The pyexpat module supports a number of new handlers, which are
2273 available only in expat 1.2. If invocation of a callback fails, it
2274 will report an additional frame in the traceback. Parser objects
2275 participate now in garbage collection. If expat reports an unknown
2276 encoding, pyexpat will try to use a Python codec; that works only
2277 for single-byte charsets. The parser type objects is exposed as
2278 XMLParserObject.
2279
2280- xml.dom now offers standard definitions for symbolic node type and
2281 exception code constants, and a hierarchy of DOM exceptions. minidom
2282 was adjusted to use them.
2283
2284- The conformance of xml.dom.minidom to the DOM specification was
2285 improved. It detects a number of additional error cases; the
2286 previous/next relationship works even when the tree is modified;
2287 Node supports the normalize() method; NamedNodeMap, DocumentType and
2288 DOMImplementation classes were added; Element supports the
2289 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2290 method.
2291
Guido van Rossumf61f1662001-01-10 20:13:55 +00002292Build issues
2293
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002294- For Unix (and Unix-compatible) builds, configuration and building of
2295 extension modules is now greatly automated. Rather than having to
2296 edit the Modules/Setup file to indicate which modules should be
2297 built and where their include files and libraries are, a
2298 distutils-based setup.py script now takes care of building most
2299 extension modules. All extension modules built this way are built
2300 as shared libraries. Only a few modules that must be linked
2301 statically are still listed in the Setup file; you won't need to
2302 edit their configuration.
2303
2304- Python should now build out of the box on Cygwin. If it doesn't,
2305 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002306
2307- Python now always uses its own (renamed) implementation of getopt()
2308 -- there's too much variation among C library getopt()
2309 implementations.
2310
2311- C++ compilers are better supported; the CXX macro is always set to a
2312 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002313
Tim Petersd92dfe02000-12-12 01:18:41 +00002314Windows changes
2315
2316- select module: By default under Windows, a select() call
2317 can specify no more than 64 sockets. Python now boosts
2318 this Microsoft default to 512. If you need even more than
2319 that, see the MS docs (you'll need to #define FD_SETSIZE
2320 and recompile Python from source).
2321
Guido van Rossumf61f1662001-01-10 20:13:55 +00002322- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2323 subdirectory is no more!
2324
Tim Petersa3a3a032000-11-30 05:22:44 +00002325
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002326What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002327=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002328
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002329Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002330changes are in the file HISTORY. If you are making the jump directly
2331from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2332HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002333
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002334Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2335the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2336http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002337
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002338--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002339
2340======================================================================
2341
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002342What's new in 2.0 (since release candidate 1)?
2343==============================================
2344
2345Standard library
2346
2347- The copy_reg module was modified to clarify its intended use: to
2348 register pickle support for extension types, not for classes.
2349 pickle() will raise a TypeError if it is passed a class.
2350
2351- Fixed a bug in gettext's "normalize and expand" code that prevented
2352 it from finding an existing .mo file.
2353
2354- Restored support for HTTP/0.9 servers in httplib.
2355
Tim Peters989b7b92000-10-16 20:24:53 +00002356- The math module was changed to stop raising OverflowError in case of
2357 underflow, and return 0 instead in underflow cases. Whether Python
2358 used to raise OverflowError in case of underflow was platform-
2359 dependent (it did when the platform math library set errno to ERANGE
2360 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002361
2362- Fixed a bug in StringIO that occurred when the file position was not
2363 at the end of the file and write() was called with enough data to
2364 extend past the end of the file.
2365
2366- Fixed a bug that caused Tkinter error messages to get lost on
2367 Windows. The bug was fixed by replacing direct use of
2368 interp->result with Tcl_GetStringResult(interp).
2369
2370- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2371 redirect response.
2372
2373- Several changes were made to distutils: Some debugging code was
2374 removed from util. Fixed the installer used when an external zip
2375 program (like WinZip) is not found; the source code for this
2376 installer is in Misc/distutils. check_lib() was modified to behave
2377 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2378 test for whether installed modules are on sys.path was changed to
2379 use both normcase() and normpath().
2380
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002381- Several minor bugs were fixed in the xml package (the minidom,
2382 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002383
2384- The regression test driver (regrtest.py) behavior when invoked with
2385 -l changed: It now reports a count of objects that are recognized as
2386 garbage but not freed by the garbage collector.
2387
Tim Peters989b7b92000-10-16 20:24:53 +00002388- The regression test for the math module was changed to test
2389 exceptional behavior when the test is run in verbose mode. Python
2390 cannot yet guarantee consistent exception behavior across platforms,
2391 so the exception part of test_math is run only in verbose mode, and
2392 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002393
2394Internals
2395
2396- PyOS_CheckStack() has been disabled on Win64, where it caused
2397 test_sre to fail.
2398
2399Build issues
2400
2401- Changed compiler flags, so that gcc is always invoked with -Wall and
2402 -Wstrict-prototypes. Users compiling Python with GCC should see
2403 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002404 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002405 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002406
Tim Petersa3a3a032000-11-30 05:22:44 +00002407- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002408
2409Tools and other miscellany
2410
2411- The compiler in Tools/compiler was updated to support the new
2412 language features introduced in 2.0: extended print statement, list
2413 comprehensions, and augmented assignments. The new compiler should
2414 also be backwards compatible with Python 1.5.2; the compiler will
2415 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002416 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002417
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002418What's new in 2.0 release candidate 1 (since beta 2)?
2419=====================================================
2420
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002421What is release candidate 1?
2422
2423We believe that release candidate 1 will fix all known bugs that we
2424intend to fix for the 2.0 final release. This release should be a bit
2425more stable than the previous betas. We would like to see even more
2426widespread testing before the final release, so we are producing this
2427release candidate. The final release will be exactly the same unless
2428any show-stopping (or brown bag) bugs are found by testers of the
2429release candidate.
2430
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002431All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002432to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002433
2434Core language, builtins, and interpreter
2435
2436- A bug that caused crashes when __coerce__ was used with augmented
2437 assignment, e.g. +=, was fixed.
2438
2439- Raise ZeroDivisionError when raising zero to a negative number,
2440 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2441 power operator and the result of math.pow(0.0, -2.0) will vary by
2442 platform. On Linux, it raises a ValueError.
2443
2444- A bug in Unicode string interpolation was fixed that occasionally
2445 caused errors with formats including "%%". For example, the
2446 following expression "%% %s" % u"abc" no longer raises a TypeError.
2447
2448- Compilation of deeply nested expressions raises MemoryError instead
2449 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2450
2451- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2452 rendering them useless. They are now written in binary mode again.
2453
2454Standard library
2455
2456- Keyword arguments are now accepted for most pattern and match object
2457 methods in SRE, the standard regular expression engine.
2458
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002459- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002460 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002461
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002462- Several bugs in the Unicode handling and error handling in _tkinter
2463 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002464
2465- Fix memory management errors in Merge() and Tkapp_Call() routines.
2466
2467- Several changes were made to cStringIO to make it compatible with
2468 the file-like object interface and with StringIO. If operations are
2469 performed on a closed object, an exception is raised. The truncate
2470 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002471 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002472
2473- There were many changes made to the linuxaudiodev module and its
2474 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002475 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002476
2477 Note that this module is named poorly, because it should work
2478 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002479 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002480
2481 The module now raises exceptions when errors occur instead of
2482 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2483 audio) and defines a getptr() method that calls the
2484 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2485
2486- The library_version attribute, introduced in an earlier beta, was
2487 removed because it can not be supported with early versions of the C
2488 readline library, which provides no way to determine the version at
2489 compile-time.
2490
2491- The binascii module is now enabled on Win64.
2492
Tim Peters46446d62000-10-09 21:19:31 +00002493- tokenize.py no longer suffers "recursion depth" errors when parsing
2494 programs with very long string literals.
2495
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002496Internals
2497
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002498- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002499 which is called when the interpreter starts up to determine where
2500 the standard library is installed. These vulnerabilities affect all
2501 previous versions of Python and can be exploited by setting very
2502 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2503 setuid Python script, although use of the wrapper in
2504 Misc/setuid-prog.c will eliminate the vulnerability.
2505
2506- Fixed garbage collection bugs in instance creation that were
2507 triggered when errors occurred during initialization. The solution,
2508 applied in cPickle and in PyInstance_New(), is to call
2509 PyObject_GC_Init() after the initialization of the object's
2510 container attributes is complete.
2511
2512- pyexpat adds definitions of PyModule_AddStringConstant and
2513 PyModule_AddObject if the Python version is less than 2.0, which
2514 provides compatibility with PyXML on Python 1.5.2.
2515
2516- If the platform has a bogus definition for LONG_BIT (the number of
2517 bits in a long), an error will be reported at compile time.
2518
2519- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2520 collection crashes and possibly other, unreported crashes.
2521
2522- Fixed a memory leak in _PyUnicode_Fini().
2523
2524Build issues
2525
2526- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002527 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002528 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002529
2530- The mmap.PAGESIZE constant is now initialized using sysconf when
2531 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2532
2533- The md5 file should now compile on all platforms.
2534
2535- The select module now compiles on platforms that do not define
2536 POLLRDNORM and related constants.
2537
2538- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002539 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002540
Jeremy Hylton10921202000-10-09 18:34:12 +00002541- BeOS: A number of changes were made to the build and installation
2542 process. ar-fake now operates on a directory of object files.
2543 dl_export.h is gone, and its macros now appear on the mwcc command
2544 line during build on PPC BeOS.
2545
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002546- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002547 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002548
2549- Cygwin: Support for shared libraries, Tkinter, and sockets.
2550
2551- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2552
2553Tools and other miscellany
2554
2555- Removed debugging prints from main used with freeze.
2556
Tim Peters46446d62000-10-09 21:19:31 +00002557- IDLE auto-indent no longer crashes when it encounters Unicode
2558 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002559
2560What's new in 2.0 beta 2 (since beta 1)?
2561========================================
2562
2563Core language, builtins, and interpreter
2564
Tim Peters482c0212000-09-26 06:33:09 +00002565- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002566 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002567
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002568- Add -h and -V command line options to print the usage message and
2569 Python version number and exit immediately.
2570
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002571- eval() and exec accept Unicode objects as code parameters.
2572
2573- getattr() and setattr() now also accept Unicode objects for the
2574 attribute name, which are converted to strings using the default
2575 encoding before lookup.
2576
2577- Multiplication on string and Unicode now does proper bounds
2578 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2579 string is too long."
2580
2581- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002582 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002583
Jeremy Hylton1b618592000-09-26 05:32:36 +00002584
2585Standard library and extensions
2586
Guido van Rossum5b08f132001-04-16 02:05:23 +00002587- socket module: the OpenSSL code now adds support for RAND_status()
2588 and EGD (Entropy Gathering Device).
2589
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002590- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002591 argument checking; it still takes no arguments.
2592
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002593- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002594
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002595- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002596
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002597- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002598
2599- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002600 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002601
2602- copy: Copy Unicode objects atomically.
2603
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002604- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002605
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002606- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002607
Fred Drake67233bc2000-09-26 16:40:27 +00002608- dbm: Add get() and setdefault() methods to dbm object. Add constant
2609 `library' to module that names the library used. Added doc strings
2610 and method names to error messages. Uses configure to determine
2611 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2612 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002613
2614- distutils: Update to version 0.9.3.
2615
2616- dl: Add several dl.RTLD_ constants.
2617
2618- fpectl: Now supported on FreeBSD.
2619
2620- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2621 found by the collector will be saved in gc.garbage. This is useful
2622 for debugging a program that creates reference cycles.
2623
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002624- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002625 of HTTP class. Do not close socket on zero-length response. Do not
2626 crash when server sends invalid content-length header.
2627
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002628- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002629
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002630- marshal: When reading a short, sign-extend on platforms where shorts
2631 are bigger than 16 bits. When reading a long, repair the unportable
2632 sign extension that was being done for 64-bit machines. (It assumed
2633 that signed right shift sign-extends.)
2634
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002635- operator: Add contains(), invert(), __invert__() as aliases for
2636 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002637
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002638- os: Add support for popen2() and popen3() on all platforms where
2639 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002640
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002641- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002642 clicking on a file in Explorer (or passing the file name to the
2643 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002644
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002645- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002646 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002647
2648- pickle: Now raises ValueError when an invalid pickle that contains
2649 a non-string repr where a string repr was expected. This behavior
2650 matches cPickle.
2651
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002652- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002653
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002654- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002655
2656- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002657 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002658 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002659
2660- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002661 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002662
2663- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002664 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002665 few cycles during startup since the first call to
2666 setdefaultencoding() will initialize the codec registry and the
2667 encodings package.
2668
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002669- socket: Support for size hint in readlines() method of object returned
2670 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002671
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002672- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002673 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002674 is followed by whitespace.
2675
Tim Petersa3a3a032000-11-30 05:22:44 +00002676- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002677
2678- struct: Check ranges for bytes and shorts.
2679
2680- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002681 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002682
2683- Tkinter: Image objects are now guaranteed to have unique ids. Set
2684 event.delta to zero if Tk version doesn't support mousewheel.
2685 Removed some debugging prints.
2686
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002687- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002688
Fred Drake67233bc2000-09-26 16:40:27 +00002689- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002690 which works around a bug in Norton AntiVirus 2000 that leads directly
2691 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002692
2693- xml: New version detection code allows PyXML to override standard
2694 XML package if PyXML version is greater than 0.6.1.
2695
Fred Drake64bb3802000-09-26 16:21:35 +00002696- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2697 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2698 tree only for nodes which are sufficiently interesting to a specific
2699 application. Does not provide the HTML-specific extensions. Still
2700 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002701
Fred Drake64bb3802000-09-26 16:21:35 +00002702- xml.sax: SAX 2 support for Python, including all the handler
2703 interfaces needed to process XML 1.0 compliant XML. Some
2704 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002705
Fred Drake64bb3802000-09-26 16:21:35 +00002706- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2707 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002708
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002709
Jeremy Hylton1b618592000-09-26 05:32:36 +00002710C API
2711
2712- Add three new convenience functions for module initialization --
2713 PyModule_AddObject(), PyModule_AddIntConstant(), and
2714 PyModule_AddStringConstant().
2715
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002716- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002717 removed and add #error to Python.h if NULL isn't defined after
2718 #include of stdio.h.
2719
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002720- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721 backwards compatibility (at the source level) with old extensions.
2722
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002723- A wrapper API was added for signal() and sigaction(). Instead of
2724 either function, always use PyOS_getsig() to get a signal handler
2725 and PyOS_setsig() to set one. A new convenience typedef
2726 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002727
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002728- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002729 internal data buffer and size of a string object -- or the default
2730 encoded version of a Unicode object.
2731
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002732- PyString_Size() and PyString_AsString() accept Unicode objects.
2733
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002734- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002735 exists). INT_MAX and LONG_MAX will always be defined, even if
2736 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002737
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002738- PyFloat_FromString takes a second argument, pend, that was
2739 effectively useless. It is now officially useless but preserved for
2740 backwards compatibility. If the pend argument is not NULL, *pend is
2741 set to NULL.
2742
2743- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2744 for the attribute name. See note on getattr() above.
2745
2746- A few bug fixes to argument processing for Unicode.
2747 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2748 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2749 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002750 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002751
2752- Py_BuildValue accepts B format (for bgen-generated code).
2753
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002754
Jeremy Hylton1b618592000-09-26 05:32:36 +00002755Internals
2756
2757- On Unix, fix code for finding Python installation directory so that
2758 it works when argv[0] is a relative path.
2759
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002760- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002761 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002762 rather than by generating a copy of the object.
2763
Tim Peters482c0212000-09-26 06:33:09 +00002764- Several of the internal Unicode tables are much smaller now, and
2765 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002766
Jeremy Hylton97693b02000-09-26 17:42:51 +00002767- In the garbage collector: Fixed bug in collection of tuples. Fixed
2768 bug that caused some instances to be removed from the container set
2769 while they were still live. Fixed parsing in gc.set_debug() for
2770 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002771
2772- Fixed refcount problem in instance deallocation that only occurred
2773 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2774
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002775- On Windows, getpythonregpath is now protected against null data in
2776 registry key.
2777
2778- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002779 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002780
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002781
Jeremy Hylton1b618592000-09-26 05:32:36 +00002782Build and platform-specific issues
2783
2784- Better support of GNU Pth via --with-pth configure option.
2785
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002786- Python/C API now properly exposed to dynamically-loaded extension
2787 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002788
2789- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2790 Don't define MS_SYNC to be zero when it is undefined. Added missing
2791 prototypes in posixmodule.c.
2792
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002793- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002794 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002795
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002796- Fix largefile support on older NetBSD systems and OpenBSD by adding
2797 define for TELL64.
2798
2799
2800Tools and other miscellany
2801
2802- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2803
2804- freeze: The modulefinder now works with 2.0 opcodes.
2805
Tim Petersa3a3a032000-11-30 05:22:44 +00002806- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002807 Move hackery of sys.argv until after the Tk instance has been
2808 created, which allows the application-specific Tkinter
2809 initialization to be executed if present; also pass an explicit
2810 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002811
Jeremy Hylton1b618592000-09-26 05:32:36 +00002812
2813What's new in 2.0 beta 1?
2814=========================
2815
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002816Source Incompatibilities
2817------------------------
2818
2819None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2820such as single-argument append(), connect() and bind(), and changes to
2821str(long) and repr(float).
2822
2823
2824Binary Incompatibilities
2825------------------------
2826
2827- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2828with Python 2.0; these extensions will have to be rebuilt for Python
28292.0.
2830
2831- On Windows, attempting to import a third party extension built for
2832Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2833can do about this. Check your PYTHONPATH environment variable!
2834
2835- Python bytecode files (*.pyc and *.pyo) are not compatible between
2836releases.
2837
2838
2839Overview of Changes Since 1.6
2840-----------------------------
2841
2842There are many new modules (including brand new XML support through
2843the xml package, and i18n support through the gettext module); a list
2844of all new modules is included below. Lots of bugs have been fixed.
2845
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002846The process for making major new changes to the language has changed
2847since Python 1.6. Enhancements must now be documented by a Python
2848Enhancement Proposal (PEP) before they can be accepted.
2849
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002850There are several important syntax enhancements, described in more
2851detail below:
2852
2853 - Augmented assignment, e.g. x += 1
2854
2855 - List comprehensions, e.g. [x**2 for x in range(10)]
2856
2857 - Extended import statement, e.g. import Module as Name
2858
2859 - Extended print statement, e.g. print >> file, "Hello"
2860
2861Other important changes:
2862
2863 - Optional collection of cyclical garbage
2864
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002865Python Enhancement Proposal (PEP)
2866---------------------------------
2867
2868PEP stands for Python Enhancement Proposal. A PEP is a design
2869document providing information to the Python community, or describing
2870a new feature for Python. The PEP should provide a concise technical
2871specification of the feature and a rationale for the feature.
2872
2873We intend PEPs to be the primary mechanisms for proposing new
2874features, for collecting community input on an issue, and for
2875documenting the design decisions that have gone into Python. The PEP
2876author is responsible for building consensus within the community and
2877documenting dissenting opinions.
2878
2879The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002880
2881Augmented Assignment
2882--------------------
2883
2884This must have been the most-requested feature of the past years!
2885Eleven new assignment operators were added:
2886
Guido van Rossume905e952000-09-05 12:42:46 +00002887 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002888
2889For example,
2890
2891 A += B
2892
2893is similar to
2894
2895 A = A + B
2896
2897except that A is evaluated only once (relevant when A is something
2898like dict[index].attr).
2899
2900However, if A is a mutable object, A may be modified in place. Thus,
2901if A is a number or a string, A += B has the same effect as A = A+B
2902(except A is only evaluated once); but if a is a list, A += B has the
2903same effect as A.extend(B)!
2904
2905Classes and built-in object types can override the new operators in
2906order to implement the in-place behavior; the not-in-place behavior is
2907used automatically as a fallback when an object doesn't implement the
2908in-place behavior. For classes, the method name is derived from the
2909method name for the corresponding not-in-place operator by inserting
2910an 'i' in front of the name, e.g. __iadd__ implements in-place
2911__add__.
2912
2913Augmented assignment was implemented by Thomas Wouters.
2914
2915
2916List Comprehensions
2917-------------------
2918
2919This is a flexible new notation for lists whose elements are computed
2920from another list (or lists). The simplest form is:
2921
2922 [<expression> for <variable> in <sequence>]
2923
Guido van Rossum56db0952000-09-06 23:34:25 +00002924For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002925This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002926
2927You can also add a condition:
2928
2929 [<expression> for <variable> in <sequence> if <condition>]
2930
2931For example, [w for w in words if w == w.lower()] would yield the list
2932of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002933than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002934
2935You can also have nested for loops and more than one 'if' clause. For
2936example, here's a function that flattens a sequence of sequences::
2937
2938 def flatten(seq):
2939 return [x for subseq in seq for x in subseq]
2940
2941 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2942
2943This prints
2944
2945 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2946
2947List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002948Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002949
2950
2951Extended Import Statement
2952-------------------------
2953
2954Many people have asked for a way to import a module under a different
2955name. This can be accomplished like this:
2956
2957 import foo
2958 bar = foo
2959 del foo
2960
2961but this common idiom gets old quickly. A simple extension of the
2962import statement now allows this to be written as follows:
2963
2964 import foo as bar
2965
2966There's also a variant for 'from ... import':
2967
2968 from foo import bar as spam
2969
2970This also works with packages; e.g. you can write this:
2971
2972 import test.regrtest as regrtest
2973
2974Note that 'as' is not a new keyword -- it is recognized only in this
2975context (this is only possible because the syntax for the import
2976statement doesn't involve expressions).
2977
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002978Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002979
2980
2981Extended Print Statement
2982------------------------
2983
2984Easily the most controversial new feature, this extension to the print
2985statement adds an option to make the output go to a different file
2986than the default sys.stdout.
2987
2988For example, to write an error message to sys.stderr, you can now
2989write:
2990
2991 print >> sys.stderr, "Error: bad dog!"
2992
2993As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002994evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002995
2996 print >> None, "Hello world"
2997
2998is equivalent to
2999
3000 print "Hello world"
3001
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003002Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003003
3004
3005Optional Collection of Cyclical Garbage
3006---------------------------------------
3007
3008Python is now equipped with a garbage collector that can hunt down
3009cyclical references between Python objects. It's no replacement for
3010reference counting; in fact, it depends on the reference counts being
3011correct, and decides that a set of objects belong to a cycle if all
3012their reference counts can be accounted for from their references to
3013each other. This devious scheme was first proposed by Eric Tiedemann,
3014and brought to implementation by Neil Schemenauer.
3015
3016There's a module "gc" that lets you control some parameters of the
3017garbage collection. There's also an option to the configure script
3018that lets you enable or disable the garbage collection. In 2.0b1,
3019it's on by default, so that we (hopefully) can collect decent user
3020experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003021performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003022off by default in the final 2.0 release.
3023
3024
3025Smaller Changes
3026---------------
3027
3028A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3029map(None, seq1, seq2, ...) when the sequences have the same length;
3030i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3031the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003032zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003033
3034sys.version_info is a tuple (major, minor, micro, level, serial).
3035
3036Dictionaries have an odd new method, setdefault(key, default).
3037dict.setdefault(key, default) returns dict[key] if it exists; if not,
3038it sets dict[key] to default and returns that value. Thus:
3039
3040 dict.setdefault(key, []).append(item)
3041
3042does the same work as this common idiom:
3043
3044 if not dict.has_key(key):
3045 dict[key] = []
3046 dict[key].append(item)
3047
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003048There are two new variants of SyntaxError that are raised for
3049indentation-related errors: IndentationError and TabError.
3050
3051Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3052escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003053
3054The limits on the size of expressions and file in Python source code
3055have been raised from 2**16 to 2**32. Previous versions of Python
3056were limited because the maximum argument size the Python VM accepted
3057was 2**16. This limited the size of object constructor expressions,
3058e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3059limit was raised thanks to a patch by Charles Waldman that effectively
3060fixes the problem. It is now much more likely that you will be
3061limited by available memory than by an arbitrary limit in Python.
3062
3063The interpreter's maximum recursion depth can be modified by Python
3064programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3065limit is the maximum number of recursive calls that can be made by
3066Python code. The limit exists to prevent infinite recursion from
3067overflowing the C stack and causing a core dump. The default value is
30681000. The maximum safe value for a particular platform can be found
3069by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003070
3071New Modules and Packages
3072------------------------
3073
3074atexit - for registering functions to be called when Python exits.
3075
3076imputil - Greg Stein's alternative API for writing custom import
3077hooks.
3078
3079pyexpat - an interface to the Expat XML parser, contributed by Paul
3080Prescod.
3081
3082xml - a new package with XML support code organized (so far) in three
3083subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3084would fill a volume. There's a special feature whereby a
3085user-installed package named _xmlplus overrides the standard
3086xmlpackage; this is intended to give the XML SIG a hook to distribute
3087backwards-compatible updates to the standard xml package.
3088
3089webbrowser - a platform-independent API to launch a web browser.
3090
3091
Guido van Rossume905e952000-09-05 12:42:46 +00003092Changed Modules
3093---------------
3094
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003095array -- new methods for array objects: count, extend, index, pop, and
3096remove
3097
3098binascii -- new functions b2a_hex and a2b_hex that convert between
3099binary data and its hex representation
3100
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003101calendar -- Many new functions that support features including control
3102over which day of the week is the first day, returning strings instead
3103of printing them. Also new symbolic constants for days of week,
3104e.g. MONDAY, ..., SUNDAY.
3105
3106cgi -- FieldStorage objects have a getvalue method that works like a
3107dictionary's get method and returns the value attribute of the object.
3108
3109ConfigParser -- The parser object has new methods has_option,
3110remove_section, remove_option, set, and write. They allow the module
3111to be used for writing config files as well as reading them.
3112
3113ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003114optionally support the RFC 959 REST command.
3115
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003116gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003117
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003118httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3119the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003120
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003121locale -- implement getdefaultlocale for Win32 and Macintosh
3122
3123marshal -- no longer dumps core when marshaling deeply nested or
3124recursive data structures
3125
3126os -- new functions isatty, seteuid, setegid, setreuid, setregid
3127
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003128os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3129support under Unix.
3130
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003131os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003132
3133os.path -- fix semantics of os.path.commonprefix
3134
3135smtplib -- support for sending very long messages
3136
3137socket -- new function getfqdn()
3138
3139readline -- new functions to read, write and truncate history files.
3140The readline section of the library reference manual contains an
3141example.
3142
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003143select -- add interface to poll system call
3144
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003145shutil -- new copyfileobj function
3146
3147SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3148HTTP server.
3149
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003150Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003151
3152urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003153e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003154
3155whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003156
3157
3158Obsolete Modules
3159----------------
3160
3161None. However note that 1.6 made a whole slew of modules obsolete:
3162stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3163poly, zmod, strop, util, whatsound.
3164
3165
3166Changed, New, Obsolete Tools
3167----------------------------
3168
Tim Peters8b092332000-09-05 20:15:25 +00003169None.
Guido van Rossume905e952000-09-05 12:42:46 +00003170
3171
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003172C-level Changes
3173---------------
3174
3175Several cleanup jobs were carried out throughout the source code.
3176
3177All C code was converted to ANSI C; we got rid of all uses of the
3178Py_PROTO() macro, which makes the header files a lot more readable.
3179
3180Most of the portability hacks were moved to a new header file,
3181pyport.h; several other new header files were added and some old
3182header files were removed, in an attempt to create a more rational set
3183of header files. (Few of these ever need to be included explicitly;
3184they are all included by Python.h.)
3185
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003186Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003187and Win64, especially for the new Intel Itanium processor. Mick also
3188added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003189
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003190The C APIs to return an object's size have been update to consistently
3191use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3192previous versions, the abstract interfaces used PyXXX_Length and the
3193concrete interfaces used PyXXX_Size. The old names,
3194e.g. PyObject_Length, are still available for backwards compatibility
3195at the API level, but are deprecated.
3196
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003197The PyOS_CheckStack function has been implemented on Windows by
3198Fredrik Lundh. It prevents Python from failing with a stack overflow
3199on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003200
3201The GC changes resulted in creation of two new slots on object,
3202tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003203the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003204
3205The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003206C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003207
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003208PyErr_Format has been updated to automatically calculate the size of
3209the buffer needed to hold the formatted result string. This change
3210prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003211
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003212New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003213
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003214PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3215that are the same as their non-Ex counterparts except they take an
3216extra flag argument that tells them to close the file when done.
3217
3218XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003219
Tim Peters8b092332000-09-05 20:15:25 +00003220
3221Windows Changes
3222---------------
3223
3224New popen2/popen3/peopen4 in os module (see Changed Modules above).
3225
3226os.popen is much more usable on Windows 95 and 98. See Microsoft
3227Knowledge Base article Q150956. The Win9x workaround described there
3228is implemented by the new w9xpopen.exe helper in the root of your
3229Python installation. Note that Python uses this internally; it is not
3230a standalone program.
3231
3232Administrator privileges are no longer required to install Python
3233on Windows NT or Windows 2000. If you have administrator privileges,
3234Python's registry info will be written under HKEY_LOCAL_MACHINE.
3235Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003236under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003237uses of Python, but will prevent some advanced uses from working
3238(for example, running a Python script as an NT service, or possibly
3239from CGI).
3240
3241[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3242installer; instead, it installs the needed Tcl/Tk files directly in the
3243Python directory. If you already have a Tcl/Tk installation, this
3244wastes some disk space (about 4 Megs) but avoids problems with
3245conflicting Tcl/Tk installations, and makes it much easier for Python
3246to ensure that Tcl/Tk can find all its files.
3247
3248[This was new in 1.6] The Windows installer now installs by default in
3249\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3250
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003251
3252Updates to the changes between 1.5.2 and 1.6
3253--------------------------------------------
3254
3255The 1.6 NEWS file can't be changed after the release is done, so here
3256is some late-breaking news:
3257
3258New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3259and changes to getlocale() and setlocale().
3260
3261The new module is now enabled per default.
3262
3263It is not true that the encodings codecs cannot be used for normal
3264strings: the string.encode() (which is also present on 8-bit strings
3265!) allows using them for 8-bit strings too, e.g. to convert files from
3266cp1252 (Windows) to latin-1 or vice-versa.
3267
3268Japanese codecs are available from Tamito KAJIYAMA:
3269http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3270
3271
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003272======================================================================