blob: 7b6b449054e1b41dca3cf8b6ff267d7ba5d6969b [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Guido van Rossum47834462002-04-04 15:21:33 +00009- A new built-in type, bool, has been added, as well as built-in
10 names for its two values, True and False. Comparisons and sundry
11 other operations that return a truth value have been changed to
12 return a bool instead. Read PEP 285 for an explanantion of why this
13 is backward compatible.
14
Guido van Rossum95b62a62002-03-29 01:07:24 +000015- Fixed two bugs reported as SF #535905: under certain conditions,
16 deallocating a deeply nested structure could cause a segfault in the
17 garbage collector, due to interaction with the "trashcan" code;
18 access to the current frame during destruction of a local variable
19 could access a pointer to freed memory.
20
Neil Schemenauer9d50d132002-03-22 17:06:59 +000021- The optional object allocator has been enabled by default.
22
Guido van Rossum8c842552002-03-14 23:05:54 +000023- If you try to pickle an instance of a class that has __slots__ but
24 doesn't define or override __getstate__, a TypeError is now raised.
25 This is done by adding a bozo __getstate__ to the class that always
26 raises TypeError. (Before, this would appear to be pickled, but the
27 state of the slots would be lost.)
28
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000029- PyErr_Display will provide file and line information for all exceptions
30 that have an attribute print_file_and_line, not just SyntaxErrors.
31
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000032- The UTF-8 codec will now encode and decode Unicode surrogates
33 correctly and without raising exceptions for unpaired ones.
34
Neal Norwitz649b7592002-01-01 19:07:13 +000035- file.xreadlines() now raises a ValueError if the file is closed:
36 Previously, an xreadlines object was returned which would raise
37 a ValueError when the xreadlines.next() method was called.
38
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000039- posix.killpg has been added where available.
40
Neal Norwitz0c766a02002-03-27 13:03:09 +000041- sys.exit() inadvertantly allowed more than one argument.
42 An exception will now be raised if more than one argument is used.
43
Tim Petersaf8446f2001-12-21 21:36:50 +000044Extension modules
45
Martin v. Löwis2e64c342002-03-27 18:49:02 +000046- The locale module now exposes the C library's gettext interface.
47
Tim Petersfbf74f22002-03-14 19:06:01 +000048- A security hole ("double free") was found in zlib-1.1.3, a popular
49 third party compression library used by some Python modules. The
50 hole was quickly plugged in zlib-1.1.4, and the Windows build of
51 Python now ships with zlib-1.1.4.
52
Martin v. Löwis29001ff2002-03-01 10:47:37 +000053- pwd and grp return enhanced tuples now, with symbolic field names.
54
Martin v. Löwis99866332002-03-01 10:27:01 +000055- array.array is now a type object. A new format character
56 'u' indicates Py_UNICODE arrays. For those, .tounicode and
57 .fromunicode methods are available. Arrays now support __iadd__
58 and __imul__.
59
Neal Norwitze790eae2002-01-01 21:14:12 +000060- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000061 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
62 is called.
63
Tim Petersaf8446f2001-12-21 21:36:50 +000064Library
65
Marc-André Lemburg4179a012002-04-05 12:15:05 +000066- The UTF-16, -LE and -BE now raise a NotImplementedError
67 for all calls to .readline(). Previously, they used to just
68 produce garbage or fail with an encoding error -- UTF-16 is
69 a 2-byte encoding and the C lib's line reading APIs don't
70 work well with these.
71
Martin v. Löwis5c137c22002-03-18 12:44:08 +000072- compileall now supports quiet operation.
73
Martin v. Löwis587c98c2002-03-17 18:37:22 +000074- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
75 connections.
76
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000077- socket module: the SSL support was broken out of the main
78 _socket module C helper and placed into a new _ssl helper
79 which now gets imported by socket.py if available and working.
80
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000081- encodings package: added aliases for all supported IANA character
82 sets
83
Guido van Rossum606fe4e2001-12-28 20:57:14 +000084- ftplib: to safeguard the user's privacy, anonymous login will use
85 "anonymous@" as default password, rather than the real user and host
86 name.
87
Fred Drake36736122002-01-10 13:50:31 +000088- webbrowser: tightened up the command passed to os.system() so that
89 arbitrary shell code can't be executed because a bogus URL was
90 passed in.
91
Tim Peters11bd9942002-02-01 00:52:29 +000092- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000093 gettext.find an optional all argument. Translations will now fallback
94 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000095
Martin v. Löwis9668b932002-01-12 11:27:42 +000096- distutils bdist commands now offer a --skip-build option.
97
Walter Dörwaldb25c2b02002-03-21 10:38:40 +000098- warnings.warn now accepts a Warning instance as first argument.
99
Fred Drakefed7e852002-04-04 19:36:15 +0000100- The xml.sax.expatreader.ExpatParser class will no longer create
101 circular references by using itself as the locator that gets passed
102 to the content handler implementation. [SF bug #535474]
103
Tim Petersaf8446f2001-12-21 21:36:50 +0000104Tools/Demos
105
Marc-André Lemburg46260092002-04-04 16:17:11 +0000106- freeze.py now produces binaries which can import shared modules,
107 unlike before when this failed due to missing symbol exports in
108 the generated binary.
109
Tim Petersaf8446f2001-12-21 21:36:50 +0000110Build
111
Martin v. Löwis1142de32002-03-29 16:28:31 +0000112- On Unix, a shared libpython2.3.so can be created with --enable-shared.
113
Tim Peters8deda702002-03-30 10:06:07 +0000114- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
115 preprocessor symbols were eliminated. The internal decisions they
116 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000117
Tim Petersaf8446f2001-12-21 21:36:50 +0000118C API
119
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000120- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
121 functions will be allocated using pymalloc if it is enabled. These
122 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
123 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
124 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
125 PyCore_* family of APIs have been removed.
126
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000127- The "u#" parser marker will now pass through Unicode object as-is
128 without going through the buffer API.
129
Martin v. Löwis7198a522002-01-01 19:59:11 +0000130- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
131
Tim Peters10a3bb52001-12-25 19:07:38 +0000132- An old #define of ANY as void has been removed from pyport.h. This
133 hasn't been used since Python's pre-ANSI days, and the #define has
134 been marked as obsolete since then. SF bug 495548 says it created
135 conflicts with other packages, so keeping it around wasn't harmless.
136
Tim Petersaf8446f2001-12-21 21:36:50 +0000137- Because Python's magic number scheme broke on January 1st, we decided
138 to stop Python development. Thanks for all the fish!
139
Tim Petersfb05db22002-03-11 00:24:00 +0000140- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000141 scheme to a new one. See Python/import.c for details.
142
Tim Petersaf8446f2001-12-21 21:36:50 +0000143New platforms
144
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000145- GNU/Hurd is now supported.
146
Tim Petersaf8446f2001-12-21 21:36:50 +0000147Tests
148
149Windows
150
Tim Peters33187922002-04-04 20:02:04 +0000151- The installer now installs Start menu shortcuts under (the local
152 equivalent of) "All Users" when doing an Admin install.
153
Tim Petersfb05db22002-03-11 00:24:00 +0000154- file.truncate([newsize]) now works on Windows for all newsize values.
155 It used to fail if newsize didn't fit in 32 bits, reflecting a
156 limitation of MS _chsize (which is no longer used).
157
Tim Petersab034fa2002-02-01 11:27:43 +0000158- os.waitpid() is now implemented for Windows, and can be used to block
159 until a specified process exits. This is similar to, but not exactly
160 the same as, os.waitpid() on POSIX systems. If you're waiting for
161 a specific process whose pid was obtained from one of the spawn()
162 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000163 See the docs for details. The docs were changed to clarify that
164 spawn functions return, and waitpid requires, a process handle on
165 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000166
Tim Peters11bd9942002-02-01 00:52:29 +0000167- New tempfile.TemporaryFile implementation for Windows: this doesn't
168 need a TemproraryFileWrapper wrapper anymore, and should be immune
169 to a nasty problem: before 2.3, if you got a temp file on Windows, it
170 got wrapped in an object whose close() method first closed the
171 underlying file, then deleted the file. This usually worked fine.
172 However, the spawn family of functions on Windows create (at a low C
173 level) the same set of open files in the spawned process Q as were
174 open in the spawning process P. If a temp file f was among them, then
175 doing f.close() in P first closed P's C-level file handle on f, but Q's
176 C-level file handle on f remained open, so the attempt in P to delete f
177 blew up with a "Permission denied" error (Windows doesn't allow
178 deleting open files). This was surprising, subtle, and difficult to
179 work around.
180
181- The os module now exports all the symbolic constants usable with the
182 low-level os.open() on Windows: the new constants in 2.3 are
183 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
184 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
185 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
186 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
187 (so specify both if you want both; note that neither is useful unless
188 specified with O_CREAT too).
189
Tim Petersaf8446f2001-12-21 21:36:50 +0000190Mac
191
192
Tim Peters909c0912001-12-14 23:16:18 +0000193What's New in Python 2.2 final?
194Release date: 21-Dec-2001
195===============================
196
197Type/class unification and new-style classes
198
Barry Warsaw52acb492001-12-21 20:04:22 +0000199- pickle.py, cPickle: allow pickling instances of new-style classes
200 with a custom metaclass.
201
Tim Peters909c0912001-12-14 23:16:18 +0000202Core and builtins
203
Barry Warsaw52acb492001-12-21 20:04:22 +0000204- weakref proxy object: when comparing, unwrap both arguments if both
205 are proxies.
206
Tim Peters909c0912001-12-14 23:16:18 +0000207Extension modules
208
Barry Warsaw52acb492001-12-21 20:04:22 +0000209- binascii.b2a_base64(): fix a potential buffer overrun when encoding
210 very short strings.
211
212- cPickle: the obscure "fast" mode was suspected of causing stack
213 overflows on the Mac. Hopefully fixed this by setting the recursion
214 limit much smaller. If the limit is too low (it only affects
215 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
216 when compiling cPickle.c (or in pyconfig.h).
217
Tim Peters909c0912001-12-14 23:16:18 +0000218Library
219
Barry Warsaw52acb492001-12-21 20:04:22 +0000220- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
221 close or delete time).
222
223- rfc822.py: fixed a bug where the address '<>' was converted to None
224 instead of an empty string (also fixes the email.Utils module).
225
226- xmlrpclib.py: version 1.0.0; uses precision for doubles.
227
228- test suite: the pickle and cPickle tests were not executing any code
229 when run from the standard regresssion test.
230
Tim Peters909c0912001-12-14 23:16:18 +0000231Tools/Demos
232
233Build
234
235C API
236
237New platforms
238
239Tests
240
241Windows
242
Barry Warsaw52acb492001-12-21 20:04:22 +0000243- distutils package: fixed broken Windows installers (bdist_wininst).
244
245- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
246 instances are deleted at process exit time.
247
248- socket.py: prevent mysterious warnings when socket instances are
249 deleted at process exit time.
250
251- posixmodule.c: fix a Windows crash with stat() of a filename ending
252 in backslash.
253
Tim Peters909c0912001-12-14 23:16:18 +0000254Mac
255
Barry Warsaw52acb492001-12-21 20:04:22 +0000256- The Carbon toolbox modules have been upgraded to Universal Headers
257 3.4, and experimental CoreGraphics and CarbonEvents modules have
258 been added. All only for framework-enabled MacOSX.
259
Tim Peters909c0912001-12-14 23:16:18 +0000260
Tim Peters6272dfd2001-12-13 19:34:00 +0000261What's New in Python 2.2c1?
262Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000263===========================
264
265Type/class unification and new-style classes
266
Barry Warsaw06557452001-12-14 20:47:12 +0000267- Guido's tutorial introduction to the new type/class features has
268 been extensively updated. See
269
270 http://www.python.org/2.2/descrintro.html
271
272 That remains the primary documentation in this area.
273
Guido van Rossum33bab012001-12-05 22:45:48 +0000274- Fixed a leak: instance variables declared with __slots__ were never
275 deleted!
276
Guido van Rossum4b800852001-12-03 00:54:52 +0000277- The "delete attribute" method of descriptor objects is called
278 __delete__, not __del__. In previous releases, it was mistakenly
279 called __del__, which created an unfortunate overloading condition
280 with finalizers. (The "get attribute" and "set attribute" methods
281 are still called __get__ and __set__, respectively.)
282
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000283- Some subtle issues with the super built-in were fixed:
284
285 (a) When super itself is subclassed, its __get__ method would still
286 return an instance of the base class (i.e., of super).
287
288 (b) super(C, C()).__class__ would return C rather than super. This
289 is confusing. To fix this, I decided to change the semantics of
290 super so that it only applies to code attributes, not to data
291 attributes. After all, overriding data attributes is not
292 supported anyway.
293
294 (c) The __get__ method didn't check whether the argument was an
295 instance of the type used in creation of the super instance.
296
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000297- Previously, hash() of an instance of a subclass of a mutable type
298 (list or dictionary) would return some value, rather than raising
299 TypeError. This has been fixed. Also, directly calling
300 dict.__hash__ and list.__hash__ now raises the same TypeError
301 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000302
Guido van Rossumd331cb52001-12-05 19:46:42 +0000303- New-style objects now support deleting their __dict__. This is for
304 all intents and purposes equivalent to assigning a brand new empty
305 dictionary, but saves space if the object is not used further.
306
Tim Petersb3c9af12001-11-17 00:21:57 +0000307Core and builtins
308
Tim Peters3caca232001-12-06 06:23:26 +0000309- -Qnew now works as documented in PEP 238: when -Qnew is passed on
310 the command line, all occurrences of "/" use true division instead
311 of classic division. See the PEP for details. Note that "all"
312 means all instances in library and 3rd-party modules, as well as in
313 your own code. As the PEP says, -Qnew is intended for use only in
314 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000315 Note that test_coercion.py in the standard Python test suite fails
316 under -Qnew; this is expected, and won't be repaired until true
317 division becomes the default (in the meantime, test_coercion is
318 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000319
Fred Drake6c01e252001-12-14 17:08:12 +0000320- complex() now only allows the first argument to be a string
321 argument, and raises TypeError if either the second arg is a string
322 or if the second arg is specified when the first is a string.
323
Tim Petersb3c9af12001-11-17 00:21:57 +0000324Extension modules
325
Martin v. Löwis560da622001-11-24 09:24:51 +0000326- gc.get_referents was renamed to gc.get_referrers.
327
Tim Petersb3c9af12001-11-17 00:21:57 +0000328Library
329
Tim Peters25059d32001-12-07 20:35:43 +0000330- Functions in the os.spawn() family now release the global interpreter
331 lock around calling the platform spawn. They should always have done
332 this, but did not before 2.2c1. Multithreaded programs calling
333 an os.spawn function with P_WAIT will no longer block all Python threads
334 until the spawned program completes. It's possible that some programs
335 relies on blocking, although more likely by accident than by design.
336
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000337- webbrowser defaults to netscape.exe on OS/2 now.
338
Martin v. Löwis652e1912001-11-25 14:50:56 +0000339- Tix.ResizeHandle exposes detach_widget, hide, and show.
340
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000341- The charset alias windows_1252 has been added.
342
Barry Warsaw06557452001-12-14 20:47:12 +0000343- types.StringTypes is a tuple containing the defined string types;
344 usually this will be (str, unicode), but if Python was compiled
345 without Unicode support it will be just (str,).
346
347- The pulldom and minidom modules were synchronized to PyXML.
348
Tim Petersb3c9af12001-11-17 00:21:57 +0000349Tools/Demos
350
Barry Warsaw06557452001-12-14 20:47:12 +0000351- A new script called Tools/scripts/google.py was added, which fires
352 off a search on Google.
353
Tim Petersb3c9af12001-11-17 00:21:57 +0000354Build
355
Barry Warsaw06557452001-12-14 20:47:12 +0000356- Note that release builds of Python should arrange to define the
357 preprocessor symbol NDEBUG on the command line (or equivalent).
358 In the 2.2 pre-release series we tried to define this by magic in
359 Python.h instead, but it proved to cause problems for extension
360 authors. The Unix, Windows and Mac builds now all define NDEBUG in
361 release builds via cmdline (or equivalent) instead. Ports to
362 other platforms should do likewise.
363
Jack Jansen1999ef42001-12-06 21:47:20 +0000364- It is no longer necessary to use --with-suffix when building on a
365 case-insensitive file system (such as Mac OS X HFS+). In the build
366 directory an extension is used, but not in the installed python.
367
Tim Petersb3c9af12001-11-17 00:21:57 +0000368C API
369
Tim Petersf582b822001-12-11 18:51:08 +0000370- New function PyDict_MergeFromSeq2() exposes the builtin dict
371 constructor's logic for updating a dictionary from an iterable object
372 producing key-value pairs.
373
Tim Peterscffed4b2001-11-29 03:26:37 +0000374- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000375 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000376 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
377 dump core in some bad cases. This has been repaired. As a result,
378 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
379 previously went unchallenged.
380
Tim Petersb3c9af12001-11-17 00:21:57 +0000381New platforms
382
383Tests
384
385Windows
386
387Mac
388
Jack Jansenffa260f2001-12-06 21:14:00 +0000389- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
390 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000391
Barry Warsaw06557452001-12-14 20:47:12 +0000392- Changed logic for finding python home in Mac OS X framework Pythons.
393 Now sys.executable points to the executable again, in stead of to
394 the shared library. The latter is used only for locating the python
395 home.
396
397
Tim Peters84362bc2001-10-19 17:55:30 +0000398What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000399Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000400===========================
401
402Type/class unification and new-style classes
403
Guido van Rossum3d27df02001-11-15 20:27:54 +0000404- Multiple inheritance mixing new-style and classic classes in the
405 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000406
407 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000408 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000409
410 The MRO (method resolution order) for each base class is respected
411 according to its kind, but the MRO for the derived class is computed
412 using new-style MRO rules if any base clase is a new-style class.
413 This needs to be documented.
414
Tim Petersa427a2b2001-10-29 22:25:45 +0000415- The new builtin dictionary() constructor, and dictionary type, have
416 been renamed to dict. This reflects a decade of common usage.
417
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000418- dict() now accepts an iterable object producing 2-sequences. For
419 example, dict(d.items()) == d for any dictionary d. The argument,
420 and the elements of the argument, can be any iterable objects.
421
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000422- New-style classes can now have a __del__ method, which is called
423 when the instance is deleted (just like for classic classes).
424
Guido van Rossum12d955c2001-10-26 14:56:06 +0000425- Assignment to object.__dict__ is now possible, for objects that are
426 instances of new-style classes that have a __dict__ (unless the base
427 class forbids it).
428
Guido van Rossumc8e56452001-10-22 00:43:43 +0000429- Methods of built-in types now properly check for keyword arguments
430 (formerly these were silently ignored). The only built-in methods
431 that take keyword arguments are __call__, __init__ and __new__.
432
Guido van Rossum86443212001-10-27 22:28:54 +0000433- The socket function has been converted to a type; see below.
434
Tim Peters84362bc2001-10-19 17:55:30 +0000435Core and builtins
436
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000437- Assignment to __debug__ raises SyntaxError at compile-time. This
438 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000439 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000440
Guido van Rossum12d955c2001-10-26 14:56:06 +0000441- Clarified the error messages for unsupported operands to an operator
442 (like 1 + '').
443
Tim Peters84362bc2001-10-19 17:55:30 +0000444Extension modules
445
Tim Peters5ebfd362001-11-13 23:11:19 +0000446- mmap has a new keyword argument, "access", allowing a uniform way for
447 both Windows and Unix users to create read-only, write-through and
448 copy-on-write memory mappings. This was previously possible only on
449 Unix. A new keyword argument was required to support this in a
450 uniform way because the mmap() signuatures had diverged across
451 platforms. Thanks to Jay T Miller for repairing this!
452
Tim Peters169ded02001-11-03 19:57:21 +0000453- By default, the gc.garbage list now contains only those instances in
454 unreachable cycles that have __del__ methods; in 2.1 it contained all
455 instances in unreachable cycles. "Instances" here has been generalized
456 to include instances of both new-style and old-style classes.
457
Guido van Rossum12d955c2001-10-26 14:56:06 +0000458- The socket module defines a new method for socket objects,
459 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000460 send() until all data has been sent. Also, the socket function has
461 been converted to a subclassable type, like list and tuple (etc.)
462 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000463
464- Various bugfixes to the curses module. There is now a test suite
465 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000466
Guido van Rossum692adf12001-10-30 03:03:03 +0000467- binascii.b2a_base64 no longer places an arbitrary restriction of 57
468 bytes on its input.
469
Tim Peters84362bc2001-10-19 17:55:30 +0000470Library
471
Tim Peters5ebfd362001-11-13 23:11:19 +0000472- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000473 convenience function.
474
Tim Peters75335872001-11-03 19:35:43 +0000475- Symbolic group names in regular expressions must be unique. For
476 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
477 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000478 Python 2.2 detects this error at regexp compilation time;
479 previously, the error went undetected, and results were
480 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
481 pattern.subn() methods have been rewritten in C. Also, an
482 experimental function/method finditer() has been added, which works
483 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000484
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000485- Tix exposes more commands through the classes DirSelectBox,
486 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
487 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
488 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
489
Tim Peters98791af2001-10-23 01:59:54 +0000490- Traceback objects are now scanned by cyclic garbage collection, so
491 cycles created by casual use of sys.exc_info() no longer cause
492 permanent memory leaks (provided garbage collection is enabled).
493
Guido van Rossum49192142001-10-24 20:51:44 +0000494- os.extsep -- a new variable needed by the RISCOS support. It is the
495 separator used by extensions, and is '.' on all platforms except
496 RISCOS, where it is '/'. There is no need to use this variable
497 unless you have a masochistic desire to port your code to RISCOS.
498
Barry Warsaw012852b2001-11-16 16:17:27 +0000499- mimetypes.py has optional support for non-standard, but commonly
500 found types. guess_type() and guess_extension() now accept an
501 optional `strict' flag, defaulting to true, which controls whether
502 recognize non-standard types or not. A few non-standard types we
503 know about have been added. Also, when run as a script, there are
504 new -l and -e options.
505
506- statcache is now deprecated.
507
508- email.Utils.formatdate() now produces the preferred RFC 2822 style
509 dates with numeric timezones (it used to produce obsolete dates
510 hard coded to "GMT" timezone). An optional `localtime' flag is
511 added to produce dates in the local timezone, with daylight savings
512 time properly taken into account.
513
514- In pickle and cPickle, instead of masking errors in load() by
515 transforming them into SystemError, we let the original exception
516 propagate out. Also, implement support for __safe_for_unpickling__
517 in pickle, as it already was supported in cPickle.
518
Tim Peters84362bc2001-10-19 17:55:30 +0000519Tools/Demos
520
521Build
522
Barry Warsaw012852b2001-11-16 16:17:27 +0000523- The dbm module is built using libdb1 if available. The bsddb module
524 is built with libdb3 if available.
525
526- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
527
Tim Peters84362bc2001-10-19 17:55:30 +0000528C API
529
Tim Peters1fc240e2001-10-26 05:06:50 +0000530- New function PySequence_Fast_GET_SIZE() returns the size of a non-
531 NULL result from PySequence_Fast(), more quickly than calling
532 PySequence_Size().
533
Barry Warsaw012852b2001-11-16 16:17:27 +0000534- New argument unpacking function PyArg_UnpackTuple() added.
535
536- New functions PyObject_CallFunctionObjArgs() and
537 PyObject_CallMethodObjArgs() have been added to make it more
538 convenient and efficient to call functions and methods from C.
539
540- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
541 possible that this will propagate errors it didn't before.
542
543- New function PyObject_CheckReadBuffer(), which returns true if its
544 argument supports the single-segment readable buffer interface.
545
Tim Peters84362bc2001-10-19 17:55:30 +0000546New platforms
547
Guido van Rossum86443212001-10-27 22:28:54 +0000548- We've finally confirmed that this release builds on HP-UX 11.00,
549 *with* threads, and passes the test suite.
550
Tim Peters7a33d8b2001-11-05 02:51:07 +0000551- Thanks to a series of patches from Michael Muller, Python may build
552 again under OS/2 Visual Age C++.
553
Guido van Rossum49192142001-10-24 20:51:44 +0000554- Updated RISCOS port by Dietmar Schwertberger.
555
Tim Peters84362bc2001-10-19 17:55:30 +0000556Tests
557
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000558- Added a test script for the curses module. It isn't run automatically;
559 regrtest.py must be run with '-u curses' to enable it.
560
Tim Peters84362bc2001-10-19 17:55:30 +0000561Windows
562
Barry Warsaw012852b2001-11-16 16:17:27 +0000563Mac
564
565- PythonScript has been moved to unsupported and is slated to be
566 removed completely in the next release.
567
568- It should now be possible to build applets that work on both OS9 and
569 OSX.
570
571- The core is now linked with CoreServices not Carbon; as a side
572 result, default 8bit encoding on OSX is now ASCII.
573
574- Python should now build on OSX 10.1.1
575
Tim Peters84362bc2001-10-19 17:55:30 +0000576
Tim Petersabf925f2001-09-28 21:53:42 +0000577What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000578Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000579===========================
580
581Type/class unification and new-style classes
582
Guido van Rossum687ae002001-10-15 22:03:32 +0000583- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000584 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000585 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000586 remains: the __dict__ of a new-style class is a read-only proxy; you
587 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000588 __defined__ attribute of new-style types no longer exists, for lack
589 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000590 future a __cache__ may be resurrected with a similar function, if I
591 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000592
Tim Peters1c9ca872001-10-04 06:43:12 +0000593- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
594 always returned None, even when there was a class docstring).
595
596- doctest now finds and runs docstrings attached to new-style classes,
597 class methods, static methods, and properties.
598
Guido van Rossum9074ef62001-10-16 21:34:49 +0000599Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000600
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000601- A very subtle syntactical pitfall in list comprehensions was fixed.
602 For example: [a+b for a in 'abc', for b in 'def']. The comma in
603 this example is a mistake. Previously, this would silently let 'a'
604 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
605 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
606 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
607 Note that [a for a in <singleton>] is a convoluted way to say
608 [<singleton>] anyway, so it's not like any expressiveness is lost.
609
Guido van Rossum9074ef62001-10-16 21:34:49 +0000610- getattr(obj, name, default) now only catches AttributeError, as
611 documented, rather than returning the default value for all
612 exceptions (which could mask bugs in a __getattr__ hook, for
613 example).
614
Fred Drakecb7a6b52001-10-22 18:41:51 +0000615- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000616 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000617 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000618 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000619
Guido van Rossum1c486092001-10-19 02:05:35 +0000620- unicode(obj) now behaves more like str(obj), accepting arbitrary
621 objects, and calling a __unicode__ method if it exists.
622 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000623 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000624
Barry Warsawf6fb1712001-10-19 05:35:40 +0000625- isinstance() now allows any object as the first argument and a
626 class, a type or something with a __bases__ tuple attribute for the
627 second argument. The second argument may also be a tuple of a
628 class, type, or something with __bases__, in which case isinstance()
629 will return true if the first argument is an instance of any of the
630 things contained in the second argument tuple. E.g.
631
632 isinstance(x, (A, B))
633
634 returns true if x is an instance of A or B.
635
Guido van Rossum9074ef62001-10-16 21:34:49 +0000636Extension modules
637
638- thread.start_new_thread() now returns the thread ID (previously None).
639
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000640- binascii has now two quopri support functions, a2b_qp and b2a_qp.
641
Guido van Rossumc524d952001-10-19 01:31:59 +0000642- readline now supports setting the startup_hook and the
643 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000644
Guido van Rossumc524d952001-10-19 01:31:59 +0000645- os and posix supports chroot(), setgroups() and unsetenv() where
646 available. The stat(), fstat(), statvfs() and fstatvfs() functions
647 now return "pseudo-sequences" -- the various fields can now be
648 accessed as attributes (e.g. os.stat("/").st_mtime) but for
649 backwards compatibility they also behave as a fixed-length sequence.
650 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000651 attributes.
652
653- time: localtime(), gmtime() and strptime() now return a
654 pseudo-sequence similar to the os.stat() return value, with
655 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000656
Guido van Rossum9074ef62001-10-16 21:34:49 +0000657- Decompression objects in the zlib module now accept an optional
658 second parameter to decompress() that specifies the maximum amount
659 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000660
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000661- optional SSL support in the socket module now exports OpenSSL
662 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
663 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000664 automatically seed its PRNG. Also, the keyfile and certfile
665 arguments to socket.ssl() are now optional.
666
667- posixmodule (and by extension, the os module on POSIX platforms) now
668 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000669
Guido van Rossum9074ef62001-10-16 21:34:49 +0000670Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000671
Tim Peters7402f792001-10-02 03:53:41 +0000672- doctest now excludes functions and classes not defined by the module
673 being tested, thanks to Tim Hochberg.
674
Fred Drakecb7a6b52001-10-22 18:41:51 +0000675- HotShot, a new profiler implemented using a C-based callback, has
676 been added. This substantially reduces the overhead of profiling,
677 but it is still quite preliminary. Support modules and
678 documentation will be added in upcoming releases (before 2.2 final).
679
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000680- profile now produces correct output in situations where an exception
681 raised in Python is cleared by C code (e.g. hasattr()). This used
682 to cause wrong output, including spurious claims of recursive
683 functions and attribution of time spent to the wrong function.
684
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000685 The code and documentation for the derived OldProfile and HotProfile
686 profiling classes was removed. The code hasn't worked for years (if
687 you tried to use them, they raised exceptions). OldProfile
688 intended to reproduce the behavior of the profiler Python used more
689 than 7 years ago, and isn't interesting anymore. HotProfile intended
690 to provide a faster profiler (but producing less information), and
691 that's a worthy goal we intend to meet via a different approach (but
692 without losing information).
693
Tim Peterscce092d2001-10-09 05:31:56 +0000694- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000695 a much better system-specific calibration constant. The constant can
696 now be specified in an instance constructor, or as a Profile class or
697 instance variable, instead of by editing profile.py's source code.
698 Calibration must still be done manually (see the docs for the profile
699 module).
700
701 Note that Profile.calibrate() must be overriden by subclasses.
702 Improving the accuracy required exploiting detailed knowledge of
703 profiler internals; the earlier method abstracted away the details
704 and measured a simplified model instead, but consequently computed
705 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000706
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000707- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000708 which indicates whether output is intended for the header 'Q'
709 encoding.
710
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000711- The SocketServer.ThreadingMixIn class now closes the request after
712 finish_request() returns. (Not when it errors out though.)
713
Barry Warsawf6fb1712001-10-19 05:35:40 +0000714- The nntplib module's NNTP.body() method has grown a `file' argument
715 to allow saving the message body to a file.
716
717- The email package has added a class email.Parser.HeaderParser which
718 only parses headers and does not recurse into the message's body.
719 Also, the module/class MIMEAudio has been added for representing
720 audio data (contributed by Anthony Baxter).
721
722- ftplib should be able to handle files > 2GB.
723
724- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
725 ON, and OFF.
726
Fred Drakecb7a6b52001-10-22 18:41:51 +0000727- xml.dom.minidom NodeList objects now support the length attribute
728 and item() method as required by the DOM specifications.
729
Guido van Rossumed554f62001-10-02 23:15:37 +0000730Tools/Demos
731
732- Demo/dns was removed. It no longer serves any purpose; a package
733 derived from it is now maintained by Anthony Baxter, see
734 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000735
Barry Warsawf6fb1712001-10-19 05:35:40 +0000736- The freeze tool has been made more robust, and two new options have
737 been added: -X and -E.
738
Tim Petersabf925f2001-09-28 21:53:42 +0000739Build
740
Barry Warsawf6fb1712001-10-19 05:35:40 +0000741- configure will use CXX in LINKCC if CXX is used to build main() and
742 the system requires to link a C++ main using the C++ compiler.
743
Tim Petersabf925f2001-09-28 21:53:42 +0000744C API
745
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000746- The documentation for the tp_compare slot is updated to require that
747 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
748 not correct. This is not yet enforced but will be enforced in
749 Python 2.3; even later, we may use -2 to indicate errors and +2 for
750 "NotImplemented". Right now, -1 should be used for an error return.
751
Tim Petersd38b1c72001-09-30 05:09:37 +0000752- PyLong_AsLongLong() now accepts int (as well as long) arguments.
753 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
754 as long) arguments.
755
Guido van Rossum3c288632001-10-16 21:13:49 +0000756- PyThread_start_new_thread() now returns a long int giving the thread
757 ID, if one can be calculated; it returns -1 for error, 0 if no
758 thread ID is calculated (this is an incompatible change, but only
759 the thread module used this API). This code has only really been
760 tested on Linux and Windows; other platforms please beware (and
761 report any bugs or strange behavior).
762
Guido van Rossum1c486092001-10-19 02:05:35 +0000763- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
764 input.
765
Tim Petersabf925f2001-09-28 21:53:42 +0000766New platforms
767
768Tests
769
770Windows
771
Tim Peters04cf1d32001-10-09 22:39:40 +0000772- Installer: If you install IDLE, and don't disable file-extension
773 registration, a new "Edit with IDLE" context (right-click) menu entry
774 is created for .py and .pyw files.
775
Tim Peters1ce3cf72001-10-01 17:58:40 +0000776- The signal module now supports SIGBREAK on Windows, thanks to Steven
777 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
778 action remains to call Win32 ExitProcess(). This can be changed via
779 signal.signal(). For example:
780
781 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
782 # (SIGINT) behavior.
783 import signal
784 signal.signal(signal.SIGBREAK,
785 signal.default_int_handler)
786
787 try:
788 while 1:
789 pass
790 except KeyboardInterrupt:
791 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
792 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
793 # program without the possibility for any Python-level cleanup).
794 print "Clean exit"
795
Tim Petersabf925f2001-09-28 21:53:42 +0000796
Tim Petersb07352e2001-09-08 01:25:47 +0000797What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000798Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000799===========================
800
Guido van Rossum808eea72001-09-25 04:15:41 +0000801Type/class unification and new-style classes
802
803- pydoc and inspect are now aware of new-style classes;
804 e.g. help(list) at the interactive prompt now shows proper
805 documentation for all operations on list objects.
806
807- Applications using Jim Fulton's ExtensionClass module can now safely
808 be used with Python 2.2. In particular, Zope 2.4.1 now works with
809 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
810 examples also work again. It is hoped that Gtk and Boost also work
811 with 2.2a4 and beyond. (If you can confirm this, please write
812 webmaster@python.org; if there are still problems, please open a bug
813 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000814
Tim Peters66c1a522001-09-24 21:17:50 +0000815- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
816 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
817 in the constructed property object. fget, fset and fdel weren't
818 discoverable from Python in 2.2a3. __doc__ is new, and allows to
819 associate a docstring with a property.
820
Guido van Rossum808eea72001-09-25 04:15:41 +0000821- Comparison overloading is now more completely implemented. For
822 example, a str subclass instance can properly be compared to a str
823 instance, and it can properly overload comparison. Ditto for most
824 other built-in object types.
825
826- The repr() of new-style classes has changed; instead of <type
827 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
828 *except* for built-in types, which are still rendered as <type
829 'Foo'> (to avoid upsetting existing code that might parse or
830 otherwise rely on repr() of certain type objects).
831
832- The repr() of new-style objects is now always <Foo object at XXX>;
833 previously, it was sometimes <Foo instance at XXX>.
834
835- For new-style classes, what was previously called __getattr__ is now
836 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000837 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000838 one in classic classes is defined which is called only if regular
839 attribute access raises AttributeError; to catch *all* attribute
840 access, you can use __getattribute__ (for new-style classes). If
841 both are defined, __getattribute__ is called first, and if it raises
842 AttributeError, __getattr__ is called.
843
844- The __class__ attribute of new-style objects can be assigned to.
845 The new class must have the same C-level object layout as the old
846 class.
847
848- The builtin file type can be subclassed now. In the usual pattern,
849 "file" is the name of the builtin type, and file() is a new builtin
850 constructor, with the same signature as the builtin open() function.
851 file() is now the preferred way to open a file.
852
853- Previously, __new__ would only see sequential arguments passed to
854 the type in a constructor call; __init__ would see both sequential
855 and keyword arguments. This made no sense whatsoever any more, so
856 now both __new__ and __init__ see all arguments.
857
858- Previously, hash() applied to an instance of a subclass of str or
859 unicode always returned 0. This has been repaired.
860
861- Previously, an operation on an instance of a subclass of an
862 immutable type (int, long, float, complex, tuple, str, unicode),
863 where the subtype didn't override the operation (and so the
864 operation was handled by the builtin type), could return that
865 instance instead a value of the base type. For example, if s was of
866 a str sublass type, s[:] returned s as-is. Now it returns a str
867 with the same value as s.
868
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000869- Provisional support for pickling new-style objects has been added.
870
Guido van Rossum808eea72001-09-25 04:15:41 +0000871Core
872
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000873- file.writelines() now accepts any iterable object producing strings.
874
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000875- PyUnicode_FromEncodedObject() now works very much like
876 PyObject_Str(obj) in that it tries to use __str__/tp_str
877 on the object if the object is not a string or buffer. This
878 makes unicode() behave like str() when applied to non-string/buffer
879 objects.
880
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000881- PyFile_WriteObject now passes Unicode objects to the file's write
882 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000883 of a print statement must support Unicode objects, i.e. they must
884 at least convert them into ASCII strings.
885
Guido van Rossum624c8af2001-09-18 15:21:04 +0000886- Thread scheduling on Solaris should be improved; it is no longer
887 necessary to insert a small sleep at the start of a thread in order
888 to let other runnable threads be scheduled.
889
Tim Petersb07352e2001-09-08 01:25:47 +0000890Library
891
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000892- StringIO.StringIO instances and cStringIO.StringIO instances support
893 read character buffer compatible objects for their .write() methods.
894 These objects are converted to strings and then handled as such
895 by the instances.
896
Barry Warsaw2f600732001-09-24 04:28:10 +0000897- The "email" package has been added. This is basically a port of the
898 mimelib package <http://sf.net/projects/mimelib> with API changes
899 and some implementations updated to use iterators and generators.
900
Tim Peters8a9c2842001-09-22 21:30:22 +0000901- difflib.ndiff() and difflib.Differ.compare() are generators now. This
902 restores the ability of Tools/scripts/ndiff.py to start producing output
903 before the entire comparison is complete.
904
Barry Warsaw58b072d2001-09-22 04:44:21 +0000905- StringIO.StringIO instances and cStringIO.StringIO instances support
906 iteration just like file objects (i.e. their .readline() method is
907 called for each iteration until it returns an empty string).
908
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000909- The codecs module has grown four new helper APIs to access
910 builtin codecs: getencoder(), getdecoder(), getreader(),
911 getwriter().
912
Guido van Rossum624c8af2001-09-18 15:21:04 +0000913- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
914 simplifies writing XML RPC servers.
915
Barry Warsaw647d5e82001-09-28 17:01:02 +0000916- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000917 after interpretation of symbolic links. On non-Unix systems, this
918 is an alias for os.path.abspath().
919
Tim Peters16a77ad2001-09-08 04:00:12 +0000920- operator.indexOf() (PySequence_Index() in the C API) now works with any
921 iterable object.
922
Guido van Rossum624c8af2001-09-18 15:21:04 +0000923- smtplib now supports various authentication and security features of
924 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000925
Guido van Rossum624c8af2001-09-18 15:21:04 +0000926- hmac: a new module implementing keyed hashing for message
927 authentication.
928
929- mimetypes now recognizes more extensions and file types. At the
930 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000931
Guido van Rossum624c8af2001-09-18 15:21:04 +0000932- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000933 Python 2.2 bytecode generation. It has also been promoted from a
934 Tool to a standard library package. (Tools/compiler still exists as
935 a sample driver.)
936
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000937Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000938
Tim Petersb07352e2001-09-08 01:25:47 +0000939Build
940
Guido van Rossum624c8af2001-09-18 15:21:04 +0000941- Large file support (LFS) is now automatic when the platform supports
942 it; no more manual configuration tweaks are needed. On Linux, at
943 least, it's possible to have a system whose C library supports large
944 files but whose kernel doesn't; in this case, large file support is
945 still enabled but doesn't do you any good unless you upgrade your
946 kernel or share your Python executable with another system whose
947 kernel has large file support.
948
949- The configure script now supplies plausible defaults in a
950 cross-compilation environment. This doesn't mean that the supplied
951 values are always correct, or that cross-compilation now works
952 flawlessly -- but it's a first step (and it shuts up most of
953 autoconf's warnings about AC_TRY_RUN).
954
955- The Unix build is now a bit less chatty, courtesy of the parser
956 generator. The build is completely silent (except for errors) when
957 using "make -s", thanks to a -q option to setup.py.
958
Tim Petersb07352e2001-09-08 01:25:47 +0000959C API
960
Guido van Rossum624c8af2001-09-18 15:21:04 +0000961- The "structmember" API now supports some new flag bits to deny read
962 and/or write access to attributes in restricted execution mode.
963
Tim Petersb07352e2001-09-08 01:25:47 +0000964New platforms
965
Guido van Rossum624c8af2001-09-18 15:21:04 +0000966- Compaq's iPAQ handheld, running the "familiar" Linux distribution
967 (http://familiar.handhelds.org).
968
Tim Petersb07352e2001-09-08 01:25:47 +0000969Tests
970
Tim Peters8a9c2842001-09-22 21:30:22 +0000971- The "classic" standard tests, which work by comparing stdout to
972 an expected-output file under Lib/test/output/, no longer stop at
973 the first mismatch. Instead the test is run to completion, and a
974 variant of ndiff-style comparison is used to report all differences.
975 This is much easier to understand than the previous style of reporting.
976
977- The unittest-based standard tests now use regrtest's test_main()
978 convention, instead of running as a side-effect of merely being
979 imported. This allows these tests to be run in more natural and
980 flexible ways as unittests, outside the regrtest framework.
981
982- regrtest.py is much better integrated with unittest and doctest now,
983 especially in regard to reporting errors.
984
Tim Petersb07352e2001-09-08 01:25:47 +0000985Windows
986
Guido van Rossum624c8af2001-09-18 15:21:04 +0000987- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000988 that support it (NTFS under Windows 2000). See "What's New in
989 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000990
Tim Petersb07352e2001-09-08 01:25:47 +0000991
Tim Petersedc99312001-08-22 21:36:50 +0000992What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000993Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000994===========================
995
996Core
997
Tim Peters9fffa3e2001-09-04 05:14:19 +0000998- Conversion of long to float now raises OverflowError if the long is too
999 big to represent as a C double.
1000
Tim Peters32f453e2001-09-03 08:35:41 +00001001- The 3-argument builtin pow() no longer allows a third non-None argument
1002 if either of the first two arguments is a float, or if both are of
1003 integer types and the second argument is negative (in which latter case
1004 the arguments are converted to float, so this is really the same
1005 restriction).
1006
Tim Peters5d2b77c2001-09-03 05:47:38 +00001007- The builtin dir() now returns more information, and sometimes much
1008 more, generally naming all attributes of an object, and all attributes
1009 reachable from the object via its class, and from its class's base
1010 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1011 an empty list. In 2.2a3,
1012
1013 >>> dir([])
1014 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1015 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1016 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1017 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1018 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1019 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1020 'reverse', 'sort']
1021
1022 dir(module) continues to return only the module's attributes, though.
1023
Tim Petersbdee63f2001-09-02 03:40:59 +00001024- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001025 than raising OverflowError. This is a partial implementation of PEP
1026 237. You can use -Wdefault::OverflowWarning to enable a warning for
1027 this situation, and -Werror::OverflowWarning to revert to the old
1028 OverflowError exception.
1029
Guido van Rossum61c345f2001-09-04 03:26:15 +00001030- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001031 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001032 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1033 -Qold, meaning the / operator has its classic meaning and no
1034 warnings are issued. Using -Qwarn issues a run-time warning about
1035 all uses of classic division for int and long arguments; -Qwarnall
1036 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001037 (for use with fixdiv.py).
1038 [Note: the remainder of this paragraph (preserved below) became
1039 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1040 <obsolete>
1041 Using -Qnew is questionable; it turns on new division by default, but
1042 only in the __main__ module. You can usefully combine -Qwarn or
1043 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1044 warns about classic division everywhere else.
1045 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001046
Tim Petersbdee63f2001-09-02 03:40:59 +00001047- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001048 long, float, str, unicode, and tuple. (The types complex, list and
1049 dictionary can also be subclassed; this was introduced earlier.)
1050 Note that restrictions apply when subclassing immutable built-in
1051 types: you can only affect the value of the instance by overloading
1052 __new__. You can add mutable attributes, and the subclass instances
1053 will have a __dict__ attribute, but you cannot change the "value"
1054 (as implemented by the base class) of an immutable subclass instance
1055 once it is created.
1056
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001057- The dictionary constructor now takes an optional argument, a
1058 mapping-like object, and initializes the dictionary from its
1059 (key, value) pairs.
1060
Tim Petersbdee63f2001-09-02 03:40:59 +00001061- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001062 "cooperative super calls" in a multiple inheritance setting. For an
1063 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1064
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001065- A new built-in type, property, has been added. This enables the
1066 creation of "properties". These are attributes implemented by
1067 getter and setter functions (or only one of these for read-only or
1068 write-only attributes), without the need to override __getattr__.
1069 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001070
Tim Petersbdee63f2001-09-02 03:40:59 +00001071- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001072 liberalized, to allow leading zeroes. Examples of literals now
1073 legal that were SyntaxErrors before:
1074
1075 00.0 0e3 0100j 07.5 00000000000000000008.
1076
Tim Petersbdee63f2001-09-02 03:40:59 +00001077- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001078 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1079
Tim Petersedc99312001-08-22 21:36:50 +00001080Library
1081
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001082- telnetlib includes symbolic names for the options, and support for
1083 setting an option negotiation callback.
1084
Tim Petersa40c7932001-09-05 22:36:56 +00001085- The new C standard no longer requires that math libraries set errno to
1086 ERANGE on overflow. For platform libraries that exploit this new
1087 freedom, Python's overflow-checking was wholly broken. A new overflow-
1088 checking scheme attempts to repair that, but may not be reliable on all
1089 platforms (C doesn't seem to provide anything both useful and portable
1090 in this area anymore).
1091
Martin v. Löwis44f86962001-09-05 13:44:54 +00001092- Asynchronous timeout actions are available through the new class
1093 threading.Timer.
1094
Tim Peters78526162001-09-05 00:53:45 +00001095- math.log and math.log10 now return sensible results for even huge
1096 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1097
Tim Petersbdee63f2001-09-02 03:40:59 +00001098- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001099 currently held. See the docs for the imp module.
1100
Tim Petersbdee63f2001-09-02 03:40:59 +00001101- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001102 dumps containing ints written on platforms where Python ints are 8 bytes.
1103 When read on a box where Python ints are 4 bytes, such values are
1104 converted to Python longs.
1105
Tim Petersbdee63f2001-09-02 03:40:59 +00001106- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001107 code objects is no longer allowed. This plugs a security hole.
1108
Steve Purcell6091cd62001-09-06 16:05:17 +00001109- unittest.TestResult instances no longer store references to tracebacks
1110 generated by test failures. This prevents unexpected dangling references
1111 to objects that should be garbage collected between tests.
1112
Tim Petersedc99312001-08-22 21:36:50 +00001113Tools
1114
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001115- Tools/scripts/fixdiv.py has been added which can be used to fix
1116 division operators as per PEP 238.
1117
Tim Petersedc99312001-08-22 21:36:50 +00001118Build
1119
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001120- If you are an adventurous person using Mac OS X you may want to look at
1121 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1122 application, which can be used for experimenting with Carbon or Cocoa.
1123 Discussion of this on pythonmac-sig, please.
1124
Tim Peters7eea37e2001-09-04 22:08:56 +00001125C API
1126
1127- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001128
Tim Peters9fffa3e2001-09-04 05:14:19 +00001129- Note that PyLong_AsDouble can fail! This has always been true, but no
1130 callers checked for it. It's more likely to fail now, because overflow
1131 errors are properly detected now. The proper way to check:
1132
1133 double x = PyLong_AsDouble(some_long_object);
1134 if (x == -1.0 && PyErr_Occurred()) {
1135 /* The conversion failed. */
1136 }
1137
Tim Petersbdee63f2001-09-02 03:40:59 +00001138- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001139 compile but will not participate in GC. To upgrade an extension
1140 module:
1141
1142 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001143
Neil Schemenauer4042c692001-08-30 15:38:01 +00001144 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1145 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001146
Neil Schemenauer4042c692001-08-30 15:38:01 +00001147 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1148 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001149
Neil Schemenauer4042c692001-08-30 15:38:01 +00001150 - remove PyGC_HEAD_SIZE from object size calculations
1151
1152 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1153
Tim Petersbdee63f2001-09-02 03:40:59 +00001154- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001155 These can be used safely to construct string objects from a
1156 sprintf-style format string (similar to the format string supported
1157 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001158
Tim Petersedc99312001-08-22 21:36:50 +00001159New platforms
1160
Tim Petersb7da0902001-09-02 23:01:43 +00001161- Stephen Hansen contributed patches sufficient to get a clean compile
1162 under Borland C (Windows), but he reports problems running it and ran
1163 out of time to complete the port. Volunteers? Expect a MemoryError
1164 when importing the types module; this is probably shallow, and
1165 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001166
Tim Petersedc99312001-08-22 21:36:50 +00001167Tests
1168
1169Windows
1170
Tim Peters6e13a562001-09-06 00:32:15 +00001171- Large file support is now enabled on Win32 platforms as well as on
1172 Win64. This means that, for example, you can use f.tell() and f.seek()
1173 to manipulate files larger than 2 gigabytes (provided you have enough
1174 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001175 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1176 filesize limit, and large file support makes no difference there.
1177 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1178 NTFS has no practical limit on file size, and files of any size can be
1179 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001180
Tim Petersbdee63f2001-09-02 03:40:59 +00001181- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001182 points to command.com (patch from Brian Quinlan).
1183
Tim Petersedc99312001-08-22 21:36:50 +00001184
Tim Peters20f51a72001-07-21 02:31:40 +00001185What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001186Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001187===========================
1188
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001189Build
1190
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001191- Tim Peters developed a brand new Windows installer using Wise 8.1,
1192 generously donated to us by Wise Solutions.
1193
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001194- configure supports a new option --enable-unicode, with the values
1195 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1196 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001197
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001198- A new configure option --enable-framework builds a Mac OS X framework,
1199 which "make frameworkinstall" will install. This provides a starting
1200 point for more mac-like functionality, join pythonmac-sig@python.org
1201 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001202
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001203- The NeXT platform is no longer supported.
1204
1205- The `new' module is now statically linked.
1206
Tim Peters0afb6092001-08-15 06:06:44 +00001207Tools
1208
1209- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001210 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001211 the module docstring for details.
1212
Tim Peters20f51a72001-07-21 02:31:40 +00001213Tests
1214
Tim Peters5e824c32001-08-12 22:25:01 +00001215- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001216 platforms, allowing to give clearer test result output. regrtest
1217 also has optional --use/-u switch to run normally disabled tests
1218 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001219
Tim Peters20f51a72001-07-21 02:31:40 +00001220- Several new tests in the standard test suite, with special thanks to
1221 Nick Mathewson.
1222
1223Core
1224
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001225- The floor division operator // has been added as outlined in PEP
1226 238. The / operator still provides classic division (and will until
1227 Python 3.0) unless "from __future__ import division" is included, in
1228 which case the / operator will provide true division. The operator
1229 module provides truediv() and floordiv() functions. Augmented
1230 assignment variants are included, as are the equivalent overloadable
1231 methods and C API methods. See the PEP for a full discussion:
1232 <http://python.sf.net/peps/pep-0238.html>
1233
Tim Peters6cd6a822001-08-17 22:11:27 +00001234- Future statements are now effective in simulated interactive shells
1235 (like IDLE). This should "just work" by magic, but read Michael
1236 Hudson's "Future statements in simulated shells" PEP 264 for full
1237 details: <http://python.sf.net/peps/pep-0264.html>.
1238
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001239- The type/class unification (PEP 252-253) was integrated into the
1240 trunk and is not so tentative any more (the exact specification of
1241 some features is still tentative). A lot of work has done on fixing
1242 bugs and adding robustness and features (performance still has to
1243 come a long way).
1244
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001245- Warnings about a mismatch in the Python API during extension import
1246 now use the Python warning framework (which makes it possible to
1247 write filters for these warnings).
1248
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001249- A function's __dict__ (aka func_dict) will now always be a
1250 dictionary. It used to be possible to delete it or set it to None,
1251 but now both actions raise TypeErrors. It is still legal to set it
1252 to a dictionary object. Getting func.__dict__ before any attributes
1253 have been assigned now returns an empty dictionary instead of None.
1254
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001255- A new command line option, -E, was added which disables the use of
1256 all environment variables, or at least those that are specifically
1257 significant to Python. Usually those have a name starting with
1258 "PYTHON". This was used to fix a problem where the tests fail if
1259 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1260 older distribution.
1261
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001262Library
1263
Tim Peters5e824c32001-08-12 22:25:01 +00001264- New class Differ and new functions ndiff() and restore() in difflib.py.
1265 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001266 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001267
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001268- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1269 value using the minimal quoting required for the value; more
1270 reliable than using xml.sax.saxutils.escape() for attribute values.
1271
1272- Readline completion support for cmd.Cmd was added.
1273
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001274- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1275
1276- Added function threading.BoundedSemaphore()
1277
1278- Added Ka-Ping Yee's cgitb.py module.
1279
1280- The `new' module now exposes the CO_xxx flags.
1281
Martin v. Löwis560da622001-11-24 09:24:51 +00001282- The gc module offers the get_referents function.
1283
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001284New platforms
1285
1286C API
1287
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001288- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1289 which provide a cross-platform implementations for the
1290 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1291 the standard sprintf() and vsprintf() C lib APIs, these versions
1292 apply bounds checking on the used buffer which enhances protection
1293 against buffer overruns.
1294
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001295- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001296 and extensions using different Unicode widths is rendered next to
1297 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001298 will result in an ImportError. Unicode extensions writers must make
1299 sure to check the Unicode width compatibility in their extensions by
1300 using at least one of the mangled Unicode APIs in the extension.
1301
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001302- Two new flags METH_NOARGS and METH_O are available in method definition
1303 tables to simplify implementation of methods with no arguments and a
1304 single untyped argument. Calling such methods is more efficient than
1305 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1306 deprecated.
1307
Tim Petersc1731372001-08-04 08:12:36 +00001308Windows
1309
1310- "import module" now compiles module.pyw if it exists and nothing else
1311 relevant is found.
1312
Tim Peters20f51a72001-07-21 02:31:40 +00001313
Guido van Rossum55a78992001-07-17 17:22:32 +00001314What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001315Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001316===========================
1317
1318Core
Tim Petersa814db52001-05-14 07:05:58 +00001319
Tim Peters6d6c1a32001-08-02 04:15:00 +00001320- TENTATIVELY, a large amount of code implementing much of what's
1321 described in PEP 252 (Making Types Look More Like Classes) and PEP
1322 253 (Subtyping Built-in Types) was added. This will be released
1323 with Python 2.2a1. Documentation will be provided separately
1324 through http://www.python.org/2.2/. The purpose of releasing this
1325 with Python 2.2a1 is to test backwards compatibility. It is
1326 possible, though not likely, that a decision is made not to release
1327 this code as part of 2.2 final, if any serious backwards
1328 incompapatibilities are found during alpha testing that cannot be
1329 repaired.
1330
Guido van Rossum55a78992001-07-17 17:22:32 +00001331- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001332 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001333 more 'yield' statements. See PEP 255. Since this adds a new
1334 keyword to the language, this feature must be enabled by including a
1335 future statement: "from __future__ import generators" (see PEP 236).
1336 Generators will become a standard feature in a future release
1337 (probably 2.3). Without this future statement, 'yield' remains an
1338 ordinary identifier, but a warning is issued each time it is used.
1339 (These warnings currently don't conform to the warnings framework of
1340 PEP 230; we intend to fix this in 2.2a2.)
1341
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001342- The UTF-16 codec was modified to be more RFC compliant. It will now
1343 only remove BOM characters at the start of the string and then
1344 only if running in native mode (UTF-16-LE and -BE won't remove a
1345 leading BMO character).
1346
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001347- Strings now have a new method .decode() to complement the already
1348 existing .encode() method. These two methods provide direct access
1349 to the corresponding decoders and encoders of the registered codecs.
1350
1351 To enhance the usability of the .encode() method, the special
1352 casing of Unicode object return values was dropped (Unicode objects
1353 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001354
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001355 Both methods will now return whatever the codec in charge of the
1356 requested encoding returns as object, e.g. Unicode codecs will
1357 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1358 will return u"äöü"). This enables codec writer to create codecs
1359 for various simple to use conversions.
1360
1361 New codecs were added to demonstrate these new features (the .encode()
1362 and .decode() columns indicate the type of the returned objects):
1363
1364 Name | .encode() | .decode() | Description
1365 ----------------------------------------------------------------------
1366 uu | string | string | UU codec (e.g. for email)
1367 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001368 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001369 zlib | string | string | zlib compression
1370 hex | string | string | 2-byte hex codec
1371 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1372
Mark Hammond2a0af792001-05-14 03:09:36 +00001373- Some operating systems now support the concept of a default Unicode
1374 encoding for file system operations. Notably, Windows supports 'mbcs'
1375 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001376 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001377 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001378
1379 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001380 functions that return filenames (such as os.listdir()) to return Python
1381 string objects pre-encoded using the default file system encoding for
1382 the platform. As this encoding is likely to be different from Python's
1383 default encoding, converting this name to a Unicode object before passing
1384 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001385 would attempt to use its default encoding (generally ASCII) rather than
1386 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001387
Tim Petersa814db52001-05-14 07:05:58 +00001388 In general, this change simply removes surprises when working with
1389 Unicode and the file system, making these operations work as you expect,
1390 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001391 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001392
Tim Peters61dff2b2001-05-08 15:43:37 +00001393- Float (and complex) literals in source code were evaluated to full
1394 precision only when running from a .py file; the same code loaded from a
1395 .pyc (or .pyo) file could suffer numeric differences starting at about the
1396 12th significant decimal digit. For example, on a machine with IEEE-754
1397 floating arithmetic,
1398
1399 x = 9007199254740992.0
1400 print long(x)
1401
1402 printed 9007199254740992 if run directly from .py, but 9007199254740000
1403 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1404 str(float) instead of repr(float) when building code objects. marshal
1405 now uses repr(float) instead, which should reproduce floats to full
1406 machine precision (assuming the platform C float<->string I/O conversion
1407 functions are of good quality).
1408
1409 This may cause floating-point results to change in some cases, and
1410 usually for the better, but may also cause numerically unstable
1411 algorithms to break.
1412
Tim Peters2f228e72001-05-13 00:19:31 +00001413- The implementation of dicts suffers fewer collisions, which has speed
1414 benefits. However, the order in which dict entries appear in dict.keys(),
1415 dict.values() and dict.items() may differ from previous releases for a
1416 given dict. Nothing is defined about this order, so no program should
1417 rely on it. Nevertheless, it's easy to write test cases that rely on the
1418 order by accident, typically because of printing the str() or repr() of a
1419 dict to an "expected results" file. See Lib/test/test_support.py's new
1420 sortdict(dict) function for a simple way to display a dict in sorted
1421 order.
1422
Tim Peters7a3bfc32001-06-12 01:22:22 +00001423- Many other small changes to dicts were made, resulting in faster
1424 operation along the most common code paths.
1425
Guido van Rossum10315822001-05-01 20:54:30 +00001426- Dictionary objects now support the "in" operator: "x in dict" means
1427 the same as dict.has_key(x).
1428
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001429- The update() method of dictionaries now accepts generic mapping
1430 objects. Specifically the argument object must support the .keys()
1431 and __getitem__() methods. This allows you to say, for example,
1432 {}.update(UserDict())
1433
Guido van Rossum10315822001-05-01 20:54:30 +00001434- Iterators were added; this is a generalized way of providing values
1435 to a for loop. See PEP 234. There's a new built-in function iter()
1436 to return an iterator. There's a new protocol to get the next value
1437 from an iterator using the next() method (in Python) or the
1438 tp_iternext slot (in C). There's a new protocol to get iterators
1439 using the __iter__() method (in Python) or the tp_iter slot (in C).
1440 Iterating (i.e. a for loop) over a dictionary generates its keys.
1441 Iterating over a file generates its lines.
1442
Tim Petersf553f892001-05-01 20:45:31 +00001443- The following functions were generalized to work nicely with iterator
1444 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001445 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001446 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1447 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001448 join() method of strings
1449 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001450 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1451 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001452 right-hand side of assignment statements with multiple targets, such as
1453 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001454
Tim Petersd85e1022001-05-11 21:51:48 +00001455- Accessing module attributes is significantly faster (for example,
1456 random.random or os.path or yourPythonModule.yourAttribute).
1457
Tim Peterse63415e2001-05-08 04:38:29 +00001458- Comparing dictionary objects via == and != is faster, and now works even
1459 if the keys and values don't support comparisons other than ==.
1460
Tim Peters95bf9392001-05-10 08:32:44 +00001461- Comparing dictionaries in ways other than == and != is slower: there were
1462 insecurities in the dict comparison implementation that could cause Python
1463 to crash if the element comparison routines for the dict keys and/or
1464 values mutated the dicts. Making the code bulletproof slowed it down.
1465
Tim Peterseb28ef22001-06-02 05:27:19 +00001466- Collisions in dicts are resolved via a new approach, which can help
1467 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001468 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001469 faster now. Thanks to Christian Tismer for pointing out the cause and
1470 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001471
Tim Peters52e155e2001-06-16 05:42:57 +00001472- repr() is much faster for large containers (dict, list, tuple).
1473
1474
Tim Petersa814db52001-05-14 07:05:58 +00001475Library
1476
Fred Drake960fdf92001-07-20 18:38:26 +00001477- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1478 were added to the string module. These a locale-indenpendent
1479 constants, unlike letters, lowercase, and uppercase. These are now
1480 use in appropriate locations in the standard library.
1481
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001482- The flags used in dlopen calls can now be configured using
1483 sys.setdlopenflags and queried using sys.getdlopenflags.
1484
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001485- Fredrik Lundh's xmlrpclib is now a standard library module. This
1486 provides full client-side XML-RPC support. In addition,
1487 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1488 one asyncore-based). Thanks to Eric Raymond for the documentation.
1489
Guido van Rossum643d3912001-07-05 14:46:25 +00001490- The xrange() object is simplified: it no longer supports slicing,
1491 repetition, comparisons, efficient 'in' checking, the tolist()
1492 method, or the start, stop and step attributes. See PEP 260.
1493
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001494- A new function fnmatch.filter to filter lists of file names was added.
1495
Barry Warsawffd674d2001-05-22 16:00:10 +00001496- calendar.py uses month and day names based on the current locale.
1497
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001498- strop is now *really* obsolete (this was announced before with 1.6),
1499 and issues DeprecationWarning when used (except for the four items
1500 that are still imported into string.py).
1501
Tim Petersa814db52001-05-14 07:05:58 +00001502- Cookie.py now sorts key+value pairs by key in output strings.
1503
1504- pprint.isrecursive(object) didn't correctly identify recursive objects.
1505 Now it does.
1506
Tim Peters95b3f782001-05-14 18:39:41 +00001507- pprint functions now much faster for large containers (tuple, list, dict).
1508
Tim Peters7b9542a2001-06-10 23:40:19 +00001509- New 'q' and 'Q' format codes in the struct module, corresponding to C
1510 types "long long" and "unsigned long long" (on Windows, __int64). In
1511 native mode, these can be used only when the platform C compiler supports
1512 these types (when HAVE_LONG_LONG is #define'd by the Python config
1513 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001514 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1515 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001516
Guido van Rossum83213cc2001-06-12 16:48:52 +00001517- The site module installs a new built-in function 'help' that invokes
1518 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1519 it displays a message reminding the user to use 'help()' or
1520 'help(object)'.
1521
Tim Petersa814db52001-05-14 07:05:58 +00001522Tests
1523
1524- New test_mutants.py runs dict comparisons where the key and value
1525 comparison operators mutute the dicts randomly during comparison. This
1526 rapidly causes Python to crash under earlier releases (not for the faint
1527 of heart: it can also cause Win9x to freeze or reboot!).
1528
1529- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001530 pprint.isreadable() return sensible results. Also verifies that simple
1531 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001532
Tim Peters4324aa32001-05-28 22:30:08 +00001533C API
1534
1535- Removed the unused last_is_sticky argument from the internal
1536 _PyTuple_Resize(). If this affects you, you were cheating.
1537
1538
Guido van Rossum55a78992001-07-17 17:22:32 +00001539======================================================================
1540
1541
Guido van Rossumffe13be2001-04-16 18:46:45 +00001542What's New in Python 2.1 (final)?
1543=================================
1544
1545We only changed a few things since the last release candidate, all in
1546Python library code:
1547
1548- A bug in the locale module was fixed that affected locales which
1549 define no grouping for numeric formatting.
1550
1551- A few bugs in the weakref module's implementations of weak
1552 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1553 and the test suite was updated to check for these bugs.
1554
1555- An old bug in the os.path.walk() function (introduced in Python
1556 2.0!) was fixed: a non-existent file would cause an exception
1557 instead of being ignored.
1558
1559- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1560 PyChecker.
1561
1562
Guido van Rossum5b08f132001-04-16 02:05:23 +00001563What's New in Python 2.1c2?
1564===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001565
Guido van Rossum5b08f132001-04-16 02:05:23 +00001566A flurry of small changes, and one showstopper fixed in the nick of
1567time made it necessary to release another release candidate. The list
1568here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001569
Guido van Rossum5b08f132001-04-16 02:05:23 +00001570Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001571
Guido van Rossum5b08f132001-04-16 02:05:23 +00001572- Tim discovered a nasty bug in the dictionary code, caused by
1573 PyDict_Next() calling dict_resize(), and the GC code's use of
1574 PyDict_Next() violating an assumption in dict_items(). This was
1575 fixed with considerable amounts of band-aid, but the net effect is a
1576 saner and more robust implementation.
1577
1578- Made a bunch of symbols static that were accidentally global.
1579
1580Build and Ports
1581
1582- The setup.py script didn't check for a new enough version of zlib
1583 (1.1.3 is needed). Now it does.
1584
1585- Changed "make clean" target to also remove shared libraries.
1586
1587- Added a more general warning about the SGI Irix optimizer to README.
1588
1589Library
1590
1591- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1592 omitted the slash between host and file.html.
1593
1594- The mailbox module's _Mailbox class contained a completely broken
1595 and undocumented seek() method. Ripped it out.
1596
1597- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1598 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1599
1600- Fixed a few last-minute bugs in unittest.
1601
1602Extensions
1603
1604- Reverted the patch to the OpenSSL code in socketmodule.c to support
1605 RAND_status() and the EGD, and the subsequent patch that tried to
1606 fix it for pre-0.9.5 versions; the problem with the patch is that on
1607 some systems it issues a warning whenever socket is imported, and
1608 that's unacceptable.
1609
1610Tests
1611
1612- Fixed the pickle tests to work with "import test.test_pickle".
1613
1614- Tweaked test_locale.py to actually run the test Windows.
1615
1616- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1617 not "wb" (which is not a valid mode at all).
1618
1619- Fix pstats browser crashes. Import readline if it exists to make
1620 the user interface nicer.
1621
1622- Add "import thread" to the top of test modules that import the
1623 threading module (test_asynchat and test_threadedtempfile). This
1624 prevents test failures caused by a broken threading module resulting
1625 from a previously caught failed import.
1626
1627- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1628 needed on some platforms (e.g. Solaris 8) when the tests are run
1629 twice in succession.
1630
1631- Skip rather than fail test_sunaudiodev if no audio device is found.
1632
1633
1634What's New in Python 2.1c1?
1635===========================
1636
1637This list was significantly updated when 2.1c2 was released; the 2.1c1
1638release didn't mention most changes that were actually part of 2.1c1:
1639
1640Legal
1641
1642- Copyright was assigned to the Python Software Foundation (PSF) and a
1643 PSF license (very similar to the CNRI license) was added.
1644
1645- The CNRI copyright notice was updated to include 2001.
1646
1647Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001648
Guido van Rossumc9932722001-04-12 02:31:27 +00001649- After a public outcry, assignment to __debug__ is no longer illegal;
1650 instead, a warning is issued. It will become illegal in 2.2.
1651
Guido van Rossum5b08f132001-04-16 02:05:23 +00001652- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1653 "%#x" now always prepends "0x", even if the value is zero.
1654
1655- Fixed some nits in the bytecode compiler.
1656
1657- Fixed core dumps when calling certain kinds of non-functions.
1658
1659- Fixed various core dumps caused by reference count bugs.
1660
1661Build and Ports
1662
1663- Use INSTALL_SCRIPT to install script files.
1664
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001665- New port: SCO Unixware 7, by Billy G. Allie.
1666
Guido van Rossum5b08f132001-04-16 02:05:23 +00001667- Updated RISCOS port.
1668
1669- Updated BeOS port and notes.
1670
1671- Various other porting problems resolved.
1672
1673Library
1674
1675- The TERMIOS and SOCKET modules are now truly obsolete and
1676 unnecessary. Their symbols are incorporated in the termios and
1677 socket modules.
1678
1679- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1680 better tests for pickling.
1681
1682- threading: make Condition.wait() robust against KeyboardInterrupt.
1683
1684- zipfile: add support to zipfile to support opening an archive
1685 represented by an open file rather than a file name. Fix bug where
1686 the archive was not properly closed. Fixed a bug in this bugfix
1687 where flush() was called for a read-only file.
1688
1689- imputil: added an uninstall() method to the ImportManager.
1690
1691- Canvas: fixed bugs in lower() and tkraise() methods.
1692
1693- SocketServer: API change (added overridable close_request() method)
1694 so that the TCP server can explicitly close the request.
1695
1696- pstats: Eric Raymond added a simple interactive statistics browser,
1697 invoked when the module is run as a script.
1698
1699- locale: fixed a problem in format().
1700
1701- webbrowser: made it work when the BROWSER environment variable has a
1702 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1703 KDE 2. Fixed some other nits.
1704
1705- unittest: changes to allow using a different exception than
1706 AssertionError, and added a few more function aliases. Some other
1707 small changes.
1708
1709- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1710
1711- asynchat: fixed a critical bug in asynchat that slipped through the
1712 2.1b2 release. Fixed another rare bug.
1713
1714- Fix some unqualified except: clauses (always a bad code example).
1715
1716XML
1717
1718- pyexpat: new API get_version_string().
1719
1720- Fixed some minidom bugs.
1721
1722Extensions
1723
1724- Fixed a core dump in _weakref. Removed the weakref.mapping()
1725 function (it adds nothing to the API).
1726
1727- Rationalized the use of header files in the readline module, to make
1728 it compile (albeit with some warnings) with the very recent readline
1729 4.2, without breaking for earlier versions.
1730
1731- Hopefully fixed a buffering problem in linuxaudiodev.
1732
1733- Attempted a fix to make the OpenSSL support in the socket module
1734 work again with pre-0.9.5 versions of OpenSSL.
1735
1736Tests
1737
1738- Added a test case for asynchat and asyncore.
1739
1740- Removed coupling between tests where one test failing could break
1741 another.
1742
1743Tools
1744
1745- Ping added an interactive help browser to pydoc, fixed some nits
1746 in the rest of the pydoc code, and added some features to his
1747 inspect module.
1748
1749- An updated python-mode.el version 4.1 which integrates Ken
1750 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1751 much nicer in XEmacs and Emacs. When stepping through your program
1752 with pdb, in either the shell window or the *Python* window, the
1753 source file and line will be tracked by an arrow. Very cool!
1754
1755- IDLE: syntax warnings in interactive mode are changed into errors.
1756
1757- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001758 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001759
1760- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001761
Barry Warsaw11e89c72001-04-11 20:37:57 +00001762
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001763What's New in Python 2.1 beta 2?
1764================================
1765
Guido van Rossum053ae352001-03-22 14:17:21 +00001766(Unlisted are many fixed bugs, more documentation, etc.)
1767
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001768Core language, builtins, and interpreter
1769
Guido van Rossum053ae352001-03-22 14:17:21 +00001770- The nested scopes work (enabled by "from __future__ import
1771 nested_scopes") is completed; in particular, the future now extends
1772 into code executed through exec, eval() and execfile(), and into the
1773 interactive interpreter.
1774
1775- When calling a base class method (e.g. BaseClass.__init__(self)),
1776 this is now allowed even if self is not strictly spoken a class
1777 instance (e.g. when using metaclasses or the Don Beaudry hook).
1778
1779- Slice objects are now comparable but not hashable; this prevents
1780 dict[:] from being accepted but meaningless.
1781
1782- Complex division is now calculated using less braindead algorithms.
1783 This doesn't change semantics except it's more likely to give useful
1784 results in extreme cases. Complex repr() now uses full precision
1785 like float repr().
1786
1787- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1788
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001789- It is illegal to assign to the name __debug__, which is set when the
1790 interpreter starts. It is effectively a compile-time constant.
1791
1792- A warning will be issued if a global statement for a variable
1793 follows a use or assignment of that variable.
1794
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001795Standard library
1796
Guido van Rossum053ae352001-03-22 14:17:21 +00001797- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1798 inspired by JUnit), is now part of the standard library. You now
1799 have a choice of two testing frameworks: unittest requires you to
1800 write testcases as separate code, doctest gathers them from
1801 docstrings. Both approaches have their advantages and
1802 disadvantages.
1803
1804- A new module Tix was added, which wraps the Tix extension library
1805 for Tk. With that module, it is not necessary to statically link
1806 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1807 require" command. See Demo/tix/.
1808
1809- tzparse.py is now obsolete.
1810
1811- In gzip.py, the seek() and tell() methods are removed -- they were
1812 non-functional anyway, and it's better if callers can test for their
1813 existence with hasattr().
1814
1815Python/C API
1816
1817- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1818 that's already in the dictionary during a PyDict_Next() iteration.
1819 This used to fail occasionally when a dictionary resize operation
1820 could be triggered that would rehash all the keys. All other
1821 modifications to the dictionary are still off-limits during a
1822 PyDict_Next() iteration!
1823
1824- New extended APIs related to passing compiler variables around.
1825
1826- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1827 implement isinstance() and issubclass().
1828
1829- Py_BuildValue() now has a "D" conversion to create a Python complex
1830 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001831
Fred Drake4e262a92001-03-22 18:26:47 +00001832- Extensions types which support weak references must now set the
1833 field allocated for the weak reference machinery to NULL themselves;
1834 this is done to avoid the cost of checking each object for having a
1835 weakly referencable type in PyObject_INIT(), since most types are
1836 not weakly referencable.
1837
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001838- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1839 free variables and cell variables to and from the frame's f_locals.
1840
1841- Variants of several functions defined in pythonrun.h have been added
1842 to support the nested_scopes future statement. The variants all end
1843 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1844 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1845 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001846 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001847
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001848Distutils
1849
1850- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1851 into the release tree.
1852
Tim Peters0e57abf2001-05-02 07:39:38 +00001853- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001854 (an uninstaller, more customization of the installer's display)
1855
1856- from Jack Jansen: added Mac-specific code to generate a dialog for
1857 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001858 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001859 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001860
1861- added 'platforms' and 'keywords' to the set of metadata that can be
1862 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001863
1864- applied patches from Jason Tishler to make the compiler class work with
1865 Cygwin.
1866
1867
Tim Peters2fe289a2001-03-01 22:19:38 +00001868What's New in Python 2.1 beta 1?
1869================================
Tim Petersd66595f2001-02-04 03:09:53 +00001870
1871Core language, builtins, and interpreter
1872
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001873- Following an outcry from the community about the amount of code
1874 broken by the nested scopes feature introduced in 2.1a2, we decided
1875 to make this feature optional, and to wait until Python 2.2 (or at
1876 least 6 months) to make it standard. The option can be enabled on a
1877 per-module basis by adding "from __future__ import nested_scopes" at
1878 the beginning of a module (before any other statements, but after
1879 comments and an optional docstring). See PEP 236 (Back to the
1880 __future__) for a description of the __future__ statement. PEP 227
1881 (Statically Nested Scopes) has been updated to reflect this change,
1882 and to clarify the semantics in a number of endcases.
1883
1884- The nested scopes code, when enabled, has been hardened, and most
1885 bugs and memory leaks in it have been fixed.
1886
1887- Compile-time warnings are now generated for a number of conditions
1888 that will break or change in meaning when nested scopes are enabled:
1889
1890 - Using "from...import *" or "exec" without in-clause in a function
1891 scope that also defines a lambda or nested function with one or
1892 more free (non-local) variables. The presence of the import* or
1893 bare exec makes it impossible for the compiler to determine the
1894 exact set of local variables in the outer scope, which makes it
1895 impossible to determine the bindings for free variables in the
1896 inner scope. To avoid the warning about import *, change it into
1897 an import of explicitly name object, or move the import* statement
1898 to the global scope; to avoid the warning about bare exec, use
1899 exec...in... (a good idea anyway -- there's a possibility that
1900 bare exec will be deprecated in the future).
1901
1902 - Use of a global variable in a nested scope with the same name as a
1903 local variable in a surrounding scope. This will change in
1904 meaning with nested scopes: the name in the inner scope will
1905 reference the variable in the outer scope rather than the global
1906 of the same name. To avoid the warning, either rename the outer
1907 variable, or use a global statement in the inner function.
1908
Neil Schemenauera35c6882001-02-27 04:45:05 +00001909- An optional object allocator has been included. This allocator is
1910 optimized for Python objects and should be faster and use less memory
1911 than the standard system allocator. It is not enabled by default
1912 because of possible thread safety problems. The allocator is only
1913 protected by the Python interpreter lock and it is possible that some
1914 extension modules require a thread safe allocator. The object
1915 allocator can be enabled by providing the "--with-pymalloc" option to
1916 configure.
1917
Tim Petersd66595f2001-02-04 03:09:53 +00001918Standard library
1919
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001920- pyexpat now detects the expat version if expat.h defines it. A
1921 number of additional handlers are provided, which are only available
1922 since expat 1.95. In addition, the methods SetParamEntityParsing and
1923 GetInputContext of Parser objects are available with 1.95.x
1924 only. Parser objects now provide the ordered_attributes and
1925 specified_attributes attributes. A new module expat.model was added,
1926 which offers a number of additional constants if 1.95.x is used.
1927
1928- xml.dom offers the new functions registerDOMImplementation and
1929 getDOMImplementation.
1930
1931- xml.dom.minidom offers a toprettyxml method. A number of DOM
1932 conformance issues have been resolved. In particular, Element now
1933 has an hasAttributes method, and the handling of namespaces was
1934 improved.
1935
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001936- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1937 getting information about live Python code, and pydoc.py, a module
1938 for interactively converting docstrings to HTML or text.
1939 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001940 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001941 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1942 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001943
Tim Peters1eff7962001-03-01 02:31:33 +00001944- New library module difflib.py, primarily packaging the SequenceMatcher
1945 class at the heart of the popular ndiff.py file-comparison tool.
1946
1947- doctest.py (a framework for verifying Python code examples in docstrings)
1948 is now part of the std library.
1949
Tim Petersd66595f2001-02-04 03:09:53 +00001950Windows changes
1951
Guido van Rossume3955a82001-03-02 14:05:59 +00001952- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1953 small GUI that lets you browse the module docstrings using your
1954 default web browser.
1955
Tim Peters1eff7962001-03-01 02:31:33 +00001956- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1957 Platforms) is implemented. See
1958
1959 http://python.sourceforge.net/peps/pep-0235.html
1960
1961 for full details, especially the "Current Lower-Left Semantics" section.
1962 The new Windows import rules are simpler than before:
1963
1964 A. If the PYTHONCASEOK environment variable exists, same as
1965 before: silently accept the first case-insensitive match of any
1966 kind; raise ImportError if none found.
1967
1968 B. Else search sys.path for the first case-sensitive match; raise
1969 ImportError if none found.
1970
1971 The same rules have been implented on other platforms with case-
1972 insensitive but case-preserving filesystems too (including Cygwin, and
1973 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001974
Tim Peters25a9ce32001-02-19 07:06:36 +00001975- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1976 what it's supposed to do (and does do under NT and 2000) via direct
1977 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001978 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001979 all Win9x systems before.
1980
Tim Peters1eff7962001-03-01 02:31:33 +00001981- Build: Subproject _test (effectively) renamed to _testcapi.
1982
Tim Peters2fe289a2001-03-01 22:19:38 +00001983New platforms
1984
1985- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1986 Thanks to Steven Majewski!
1987
1988- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1989 Tishler!
1990
Guido van Rossum9089b272001-03-02 06:49:50 +00001991- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1992 Schwertberger! See RISCOS/README for more information -- it seems
1993 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001994 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001995
Tim Peters25a9ce32001-02-19 07:06:36 +00001996
Tim Petersd7b5e882001-01-25 03:36:26 +00001997What's New in Python 2.1 alpha 2?
1998=================================
Tim Peters40ead762001-01-27 05:35:26 +00001999
Tim Petersd7b5e882001-01-25 03:36:26 +00002000Core language, builtins, and interpreter
2001
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002002- Scopes nest. If a name is used in a function or class, but is not
2003 local, the definition in the nearest enclosing function scope will
2004 be used. One consequence of this change is that lambda statements
2005 could reference variables in the namespaces where the lambda is
2006 defined. In some unusual cases, this change will break code.
2007
2008 In all previous version of Python, names were resolved in exactly
2009 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002010 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002011 function A is defined within a function B, the names bound in B are
2012 not visible in A. The new rules make names bound in B visible in A,
2013 unless A contains a name binding that hides the binding in B.
2014
2015 Section 4.1 of the reference manual describes the new scoping rules
2016 in detail. The test script in Lib/test/test_scope.py demonstrates
2017 some of the effects of the change.
2018
2019 The new rules will cause existing code to break if it defines nested
2020 functions where an outer function has local variables with the same
2021 name as globals or builtins used by the inner function. Example:
2022
2023 def munge(str):
2024 def helper(x):
2025 return str(x)
2026 if type(str) != type(''):
2027 str = helper(str)
2028 return str.strip()
2029
2030 Under the old rules, the name str in helper() is bound to the
2031 builtin function str(). Under the new rules, it will be bound to
2032 the argument named str and an error will occur when helper() is
2033 called.
2034
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002035- The compiler will report a SyntaxError if "from ... import *" occurs
2036 in a function or class scope. The language reference has documented
2037 that this case is illegal, but the compiler never checked for it.
2038 The recent introduction of nested scope makes the meaning of this
2039 form of name binding ambiguous. In a future release, the compiler
2040 may allow this form when there is no possibility of ambiguity.
2041
Tim Peters40ead762001-01-27 05:35:26 +00002042- repr(string) is easier to read, now using hex escapes instead of octal,
2043 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2044
2045 >>> "\texample \r\n" + chr(0) + chr(255)
2046 '\texample \r\n\x00\xff' # in 2.1
2047 '\011example \015\012\000\377' # in 2.0
2048
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002049- Functions are now compared and hashed by identity, not by value, since
2050 the func_code attribute is writable.
2051
Fred Drakefb9d7122001-02-01 20:00:40 +00002052- Weak references (PEP 205) have been added. This involves a few
2053 changes in the core, an extension module (_weakref), and a Python
2054 module (weakref). The weakref module is the public interface. It
2055 includes support for "explicit" weak references, proxy objects, and
2056 mappings with weakly held values.
2057
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002058- A 'continue' statement can now appear in a try block within the body
2059 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002060 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002061
Tim Petersd7b5e882001-01-25 03:36:26 +00002062Standard library
2063
Barry Warsaw30dbd142001-01-31 22:14:01 +00002064- mailbox.py now has a new class, PortableUnixMailbox which is
2065 identical to UnixMailbox but uses a more portable scheme for
2066 determining From_ separators. Also, the constructors for all the
2067 classes in this module have a new optional `factory' argument, which
2068 is a callable used when new message classes must be instantiated by
2069 the next() method.
2070
Tim Petersd7b5e882001-01-25 03:36:26 +00002071- random.py is now self-contained, and offers all the functionality of
2072 the now-deprecated whrandom.py. See the docs for details. random.py
2073 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002074 and restoring the internal state of the generator; and jumpahead(n),
2075 for quickly forcing the internal state to be the same as if n calls to
2076 random() had been made. The latter is particularly useful for multi-
2077 threaded programs, creating one instance of the random.Random() class for
2078 each thread, then using .jumpahead() to force each instance to use a
2079 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002080
Tim Peters0de88fc2001-02-01 04:59:18 +00002081- random.py's seed() function is new. For bit-for-bit compatibility with
2082 prior releases, use the whseed function instead. The new seed function
2083 addresses two problems: (1) The old function couldn't produce more than
2084 about 2**24 distinct internal states; the new one about 2**45 (the best
2085 that can be done in the Wichmann-Hill generator). (2) The old function
2086 sometimes produced identical internal states when passed distinct
2087 integers, and there was no simple way to predict when that would happen;
2088 the new one guarantees to produce distinct internal states for all
2089 arguments in [0, 27814431486576L).
2090
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002091- The socket module now supports raw packets on Linux. The socket
2092 family is AF_PACKET.
2093
Tim Peters9ea17ac2001-02-02 05:57:15 +00002094- test_capi.py is a start at running tests of the Python C API. The tests
2095 are implemented by the new Modules/_testmodule.c.
2096
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002097- A new extension module, _symtable, provides provisional access to the
2098 internal symbol table used by the Python compiler. A higher-level
2099 interface will be added on top of _symtable in a future release.
2100
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002101- Removed the obsolete soundex module.
2102
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002103- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2104 the isSameNode method; NamedNodeMap the get method.
2105
2106- xml.sax.expatreader supports the lexical handler property; it
2107 generates comment, startCDATA, and endCDATA events.
2108
Tim Petersee826f82001-01-31 19:39:44 +00002109Windows changes
2110
2111- Build procedure: the zlib project is built in a different way that
2112 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002113 the zlib binary used. See PCbuild\readme.txt for details. Your old
2114 zlib-related directories can be deleted; you'll need to download fresh
2115 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002116
Tim Peters9ea17ac2001-02-02 05:57:15 +00002117- Build: New subproject _test for the benefit of test_capi.py (see above).
2118
Tim Petersb16c56f2001-02-02 21:24:51 +00002119- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2120 interface to some Python compiler internals).
2121
2122- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002123 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002124
Tim Petersa3a3a032000-11-30 05:22:44 +00002125What's New in Python 2.1 alpha 1?
2126=================================
2127
2128Core language, builtins, and interpreter
2129
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002130- There is a new Unicode companion to the PyObject_Str() API
2131 called PyObject_Unicode(). It behaves in the same way as the
2132 former, but assures that the returned value is an Unicode object
2133 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002134
Guido van Rossumf98eda02001-01-17 15:54:45 +00002135- The comparison operators support "rich comparison overloading" (PEP
2136 207). C extension types can provide a rich comparison function in
2137 the new tp_richcompare slot in the type object. The cmp() function
2138 and the C function PyObject_Compare() first try the new rich
2139 comparison operators before trying the old 3-way comparison. There
2140 is also a new C API PyObject_RichCompare() (which also falls back on
2141 the old 3-way comparison, but does not constrain the outcome of the
2142 rich comparison to a Boolean result).
2143
2144 The rich comparison function takes two objects (at least one of
2145 which is guaranteed to have the type that provided the function) and
2146 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2147 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2148 object, which may be NotImplemented (in which case the tp_compare
2149 slot function is used as a fallback, if defined).
2150
2151 Classes can overload individual comparison operators by defining one
2152 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002153 __ge__. There are no explicit "reflected argument" versions of
2154 these; instead, __lt__ and __gt__ are each other's reflection,
2155 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2156 reflection (similar at the C level). No other implications are
2157 made; in particular, Python does not assume that == is the Boolean
2158 inverse of !=, or that < is the Boolean inverse of >=. This makes
2159 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002160
2161 Classes or types that want to implement (in)equality tests but not
2162 the ordering operators (i.e. unordered types) should implement ==
2163 and !=, and raise an error for the ordering operators.
2164
Guido van Rossuma88479f2001-01-18 14:28:08 +00002165 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002166 Boolean; e.g. a matrix type might want to return a matrix of bits
2167 for A < B, giving elementwise comparisons. Such types should ensure
2168 that any interpretation of their value in a Boolean context raises
2169 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2170 at the C level) to always raise an exception.
2171
Guido van Rossuma88479f2001-01-18 14:28:08 +00002172- Complex numbers use rich comparisons to define == and != but raise
2173 an exception for <, <=, > and >=. Unfortunately, this also means
2174 that cmp() of two complex numbers raises an exception when the two
2175 numbers differ. Since it is not mathematically meaningful to compare
2176 complex numbers except for equality, I hope that this doesn't break
2177 too much code.
2178
Tim Peters3389f192001-02-18 08:48:49 +00002179- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002180 not defined by the language, other than that it's arbitrary but
2181 consistent (see the Reference Manual). An implementation detail changed
2182 in 2.1a1 such that None now compares less than any other object. Code
2183 relying on this new behavior (like code that relied on the previous
2184 behavior) does so at its own risk.
2185
Barry Warsaw573b5412001-01-15 20:43:18 +00002186- Functions and methods now support getting and setting arbitrarily
2187 named attributes (PEP 232). Functions have a new __dict__
2188 (a.k.a. func_dict) which hold the function attributes. Methods get
2189 and set attributes on their underlying im_func. It is a TypeError
2190 to set an attribute on a bound method.
2191
Guido van Rossum051e3352001-01-15 19:11:10 +00002192- The xrange() object implementation has been improved so that
2193 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2194 limitation that in this case len(xrange(sys.maxint)) can't be
2195 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2196 work fine as long as the index i doesn't actually reach 2**31.
2197 (Python uses regular ints for sequence and string indices; fixing
2198 that is much more work.)
2199
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002200- Two changes to from...import:
2201
Guido van Rossumba381232001-02-03 15:06:40 +00002202 1) "from M import X" now works even if (after loading module M)
2203 sys.modules['M'] is not a real module; it's basically a getattr()
2204 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002205
2206 2) "from M import *" now looks for M.__all__ to decide which names to
2207 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2208 filters out names starting with '_' as before. Whether or not
2209 __all__ exists, there's no restriction on the type of M.
2210
Guido van Rossumf61f1662001-01-10 20:13:55 +00002211- File objects have a new method, xreadlines(). This is the fastest
2212 way to iterate over all lines in a file:
2213
2214 for line in file.xreadlines():
2215 ...do something to line...
2216
2217 See the xreadlines module (mentioned below) for how to do this for
2218 other file-like objects.
2219
2220- Even if you don't use file.xreadlines(), you may expect a speedup on
2221 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002222 quite a bit in platform-specific ways: on systems (like Linux) that
2223 support flockfile(), getc_unlocked(), and funlockfile(), those are
2224 used by default. On systems (like Windows) without getc_unlocked(),
2225 a complicated (but still thread-safe) method using fgets() is used by
2226 default.
2227
Tim Petersd52269b2001-01-25 06:23:18 +00002228 You can force use of the fgets() method by #define'ing
2229 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002230 getc_unlocked()).
2231
Tim Petersd52269b2001-01-25 06:23:18 +00002232 You can force fgets() not to be used by #define'ing
2233 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002234 test_bufio.py fails -- and let us know if it does!).
2235
2236- In addition, the fileinput module, while still slower than the other
2237 methods on most platforms, has been sped up too, by using
2238 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002239
2240- Support for run-time warnings has been added, including a new
2241 command line option (-W) to specify the disposition of warnings.
2242 See the description of the warnings module below.
2243
2244- Extensive changes have been made to the coercion code. This mostly
2245 affects extension modules (which can now implement mixed-type
2246 numerical operators without having to use coercion), but
2247 occasionally, in boundary cases the coercion semantics have changed
2248 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002249 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002250 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002251 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002252
Guido van Rossumf98eda02001-01-17 15:54:45 +00002253- In connection with the coercion changes, a new built-in singleton
2254 object, NotImplemented is defined. This can be returned for
2255 operations that wish to indicate they are not implemented for a
2256 particular combination of arguments. From C, this is
2257 Py_NotImplemented.
2258
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002259- The interpreter accepts now bytecode files on the command line even
2260 if they do not have a .pyc or .pyo extension. On Linux, after executing
2261
Martin v. Löwise214baa2001-02-04 22:37:56 +00002262import imp,sys,string
2263magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2264reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2265open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002266
2267 any byte code file can be used as an executable (i.e. as an argument
2268 to execve(2)).
2269
Tim Peters9940b802000-12-01 07:59:35 +00002270- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002271 character. In 1.6 and earlier, they never produced a sign,
2272 and raised an error if the value of the long was too large
2273 to fit in a Python int. In 2.0, they produced a sign if and
2274 only if too large to fit in an int. This was inconsistent
2275 across platforms (because the size of an int varies across
2276 platforms), and inconsistent with hex() and oct(). Example:
2277
2278 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002279 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002280 'ffffffbe' # in 2.0 and before, on 32-bit machines
2281 >>> hex(-0x42L)
2282 '-0x42L' # in all versions of Python
2283
Tim Peters9940b802000-12-01 07:59:35 +00002284 The behavior of %d formats for negative Python longs remains
2285 the same as in 2.0 (although in 1.6 and before, they raised
2286 an error if the long didn't fit in a Python int).
2287
2288 %u formats don't make sense for Python longs, but are allowed
2289 and treated the same as %d in 2.1. In 2.0, a negative long
2290 formatted via %u produced a sign if and only if too large to
2291 fit in an int. In 1.6 and earlier, a negative long formatted
2292 via %u raised an error if it was too big to fit in an int.
2293
Guido van Rossum3661d392000-12-12 22:10:31 +00002294- Dictionary objects have an odd new method, popitem(). This removes
2295 an arbitrary item from the dictionary and returns it (in the form of
2296 a (key, value) pair). This can be useful for algorithms that use a
2297 dictionary as a bag of "to do" items and repeatedly need to pick one
2298 item. Such algorithms normally end up running in quadratic time;
2299 using popitem() they can usually be made to run in linear time.
2300
Tim Peters36cdad12000-12-29 02:06:45 +00002301Standard library
2302
Thomas Woutersfe385252001-01-19 23:16:56 +00002303- In the time module, the time argument to the functions strftime,
2304 localtime, gmtime, asctime and ctime is now optional, defaulting to
2305 the current time (in the local timezone).
2306
Guido van Rossumda91f222001-01-15 16:36:08 +00002307- The ftplib module now defaults to passive mode, which is deemed a
2308 more useful default given that clients are often inside firewalls
2309 these days. Note that this could break if ftplib is used to connect
2310 to a *server* that is inside a firewall, from outside; this is
2311 expected to be a very rare situation. To fix that, you can call
2312 ftp.set_pasv(0).
2313
Martin v. Löwis10a27872001-01-13 09:54:41 +00002314- The module site now treats .pth files not only for path configuration,
2315 but also supports extensions to the initialization code: Lines starting
2316 with import are executed.
2317
Guido van Rossumf61f1662001-01-10 20:13:55 +00002318- There's a new module, warnings, which implements a mechanism for
2319 issuing and filtering warnings. There are some new built-in
2320 exceptions that serve as warning categories, and a new command line
2321 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2322 turns warnings into errors). warnings.warn(message[, category])
2323 issues a warning message; this can also be called from C as
2324 PyErr_Warn(category, message).
2325
2326- A new module xreadlines was added. This exports a single factory
2327 function, xreadlines(). The intention is that this code is the
2328 absolutely fastest way to iterate over all lines in an open
2329 file(-like) object:
2330
2331 import xreadlines
2332 for line in xreadlines.xreadlines(file):
2333 ...do something to line...
2334
2335 This is equivalent to the previous the speed record holder using
2336 file.readlines(sizehint). Note that if file is a real file object
2337 (as opposed to a file-like object), this is equivalent:
2338
2339 for line in file.xreadlines():
2340 ...do something to line...
2341
Tim Peters36cdad12000-12-29 02:06:45 +00002342- The bisect module has new functions bisect_left, insort_left,
2343 bisect_right and insort_right. The old names bisect and insort
2344 are now aliases for bisect_right and insort_right. XXX_right
2345 and XXX_left methods differ in what happens when the new element
2346 compares equal to one or more elements already in the list: the
2347 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002348 right. Code that doesn't care where equal elements end up should
2349 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002350
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002351- The new curses.panel module wraps the panel library that forms part
2352 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2353
Guido van Rossumf61f1662001-01-10 20:13:55 +00002354- The SocketServer module now sets the allow_reuse_address flag by
2355 default in the TCPServer class.
2356
2357- A new function, sys._getframe(), returns the stack frame pointer of
2358 the caller. This is intended only as a building block for
2359 higher-level mechanisms such as string interpolation.
2360
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002361- The pyexpat module supports a number of new handlers, which are
2362 available only in expat 1.2. If invocation of a callback fails, it
2363 will report an additional frame in the traceback. Parser objects
2364 participate now in garbage collection. If expat reports an unknown
2365 encoding, pyexpat will try to use a Python codec; that works only
2366 for single-byte charsets. The parser type objects is exposed as
2367 XMLParserObject.
2368
2369- xml.dom now offers standard definitions for symbolic node type and
2370 exception code constants, and a hierarchy of DOM exceptions. minidom
2371 was adjusted to use them.
2372
2373- The conformance of xml.dom.minidom to the DOM specification was
2374 improved. It detects a number of additional error cases; the
2375 previous/next relationship works even when the tree is modified;
2376 Node supports the normalize() method; NamedNodeMap, DocumentType and
2377 DOMImplementation classes were added; Element supports the
2378 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2379 method.
2380
Guido van Rossumf61f1662001-01-10 20:13:55 +00002381Build issues
2382
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002383- For Unix (and Unix-compatible) builds, configuration and building of
2384 extension modules is now greatly automated. Rather than having to
2385 edit the Modules/Setup file to indicate which modules should be
2386 built and where their include files and libraries are, a
2387 distutils-based setup.py script now takes care of building most
2388 extension modules. All extension modules built this way are built
2389 as shared libraries. Only a few modules that must be linked
2390 statically are still listed in the Setup file; you won't need to
2391 edit their configuration.
2392
2393- Python should now build out of the box on Cygwin. If it doesn't,
2394 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002395
2396- Python now always uses its own (renamed) implementation of getopt()
2397 -- there's too much variation among C library getopt()
2398 implementations.
2399
2400- C++ compilers are better supported; the CXX macro is always set to a
2401 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002402
Tim Petersd92dfe02000-12-12 01:18:41 +00002403Windows changes
2404
2405- select module: By default under Windows, a select() call
2406 can specify no more than 64 sockets. Python now boosts
2407 this Microsoft default to 512. If you need even more than
2408 that, see the MS docs (you'll need to #define FD_SETSIZE
2409 and recompile Python from source).
2410
Guido van Rossumf61f1662001-01-10 20:13:55 +00002411- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2412 subdirectory is no more!
2413
Tim Petersa3a3a032000-11-30 05:22:44 +00002414
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002415What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002416=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002417
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002418Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002419changes are in the file HISTORY. If you are making the jump directly
2420from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2421HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002422
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002423Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2424the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2425http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002426
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002427--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002428
2429======================================================================
2430
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002431What's new in 2.0 (since release candidate 1)?
2432==============================================
2433
2434Standard library
2435
2436- The copy_reg module was modified to clarify its intended use: to
2437 register pickle support for extension types, not for classes.
2438 pickle() will raise a TypeError if it is passed a class.
2439
2440- Fixed a bug in gettext's "normalize and expand" code that prevented
2441 it from finding an existing .mo file.
2442
2443- Restored support for HTTP/0.9 servers in httplib.
2444
Tim Peters989b7b92000-10-16 20:24:53 +00002445- The math module was changed to stop raising OverflowError in case of
2446 underflow, and return 0 instead in underflow cases. Whether Python
2447 used to raise OverflowError in case of underflow was platform-
2448 dependent (it did when the platform math library set errno to ERANGE
2449 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002450
2451- Fixed a bug in StringIO that occurred when the file position was not
2452 at the end of the file and write() was called with enough data to
2453 extend past the end of the file.
2454
2455- Fixed a bug that caused Tkinter error messages to get lost on
2456 Windows. The bug was fixed by replacing direct use of
2457 interp->result with Tcl_GetStringResult(interp).
2458
2459- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2460 redirect response.
2461
2462- Several changes were made to distutils: Some debugging code was
2463 removed from util. Fixed the installer used when an external zip
2464 program (like WinZip) is not found; the source code for this
2465 installer is in Misc/distutils. check_lib() was modified to behave
2466 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2467 test for whether installed modules are on sys.path was changed to
2468 use both normcase() and normpath().
2469
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002470- Several minor bugs were fixed in the xml package (the minidom,
2471 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002472
2473- The regression test driver (regrtest.py) behavior when invoked with
2474 -l changed: It now reports a count of objects that are recognized as
2475 garbage but not freed by the garbage collector.
2476
Tim Peters989b7b92000-10-16 20:24:53 +00002477- The regression test for the math module was changed to test
2478 exceptional behavior when the test is run in verbose mode. Python
2479 cannot yet guarantee consistent exception behavior across platforms,
2480 so the exception part of test_math is run only in verbose mode, and
2481 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002482
2483Internals
2484
2485- PyOS_CheckStack() has been disabled on Win64, where it caused
2486 test_sre to fail.
2487
2488Build issues
2489
2490- Changed compiler flags, so that gcc is always invoked with -Wall and
2491 -Wstrict-prototypes. Users compiling Python with GCC should see
2492 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002493 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002494 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002495
Tim Petersa3a3a032000-11-30 05:22:44 +00002496- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002497
2498Tools and other miscellany
2499
2500- The compiler in Tools/compiler was updated to support the new
2501 language features introduced in 2.0: extended print statement, list
2502 comprehensions, and augmented assignments. The new compiler should
2503 also be backwards compatible with Python 1.5.2; the compiler will
2504 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002505 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002506
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002507What's new in 2.0 release candidate 1 (since beta 2)?
2508=====================================================
2509
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002510What is release candidate 1?
2511
2512We believe that release candidate 1 will fix all known bugs that we
2513intend to fix for the 2.0 final release. This release should be a bit
2514more stable than the previous betas. We would like to see even more
2515widespread testing before the final release, so we are producing this
2516release candidate. The final release will be exactly the same unless
2517any show-stopping (or brown bag) bugs are found by testers of the
2518release candidate.
2519
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002520All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002521to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002522
2523Core language, builtins, and interpreter
2524
2525- A bug that caused crashes when __coerce__ was used with augmented
2526 assignment, e.g. +=, was fixed.
2527
2528- Raise ZeroDivisionError when raising zero to a negative number,
2529 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2530 power operator and the result of math.pow(0.0, -2.0) will vary by
2531 platform. On Linux, it raises a ValueError.
2532
2533- A bug in Unicode string interpolation was fixed that occasionally
2534 caused errors with formats including "%%". For example, the
2535 following expression "%% %s" % u"abc" no longer raises a TypeError.
2536
2537- Compilation of deeply nested expressions raises MemoryError instead
2538 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2539
2540- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2541 rendering them useless. They are now written in binary mode again.
2542
2543Standard library
2544
2545- Keyword arguments are now accepted for most pattern and match object
2546 methods in SRE, the standard regular expression engine.
2547
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002548- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002549 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002550
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002551- Several bugs in the Unicode handling and error handling in _tkinter
2552 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002553
2554- Fix memory management errors in Merge() and Tkapp_Call() routines.
2555
2556- Several changes were made to cStringIO to make it compatible with
2557 the file-like object interface and with StringIO. If operations are
2558 performed on a closed object, an exception is raised. The truncate
2559 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002560 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002561
2562- There were many changes made to the linuxaudiodev module and its
2563 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002564 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002565
2566 Note that this module is named poorly, because it should work
2567 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002568 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002569
2570 The module now raises exceptions when errors occur instead of
2571 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2572 audio) and defines a getptr() method that calls the
2573 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2574
2575- The library_version attribute, introduced in an earlier beta, was
2576 removed because it can not be supported with early versions of the C
2577 readline library, which provides no way to determine the version at
2578 compile-time.
2579
2580- The binascii module is now enabled on Win64.
2581
Tim Peters46446d62000-10-09 21:19:31 +00002582- tokenize.py no longer suffers "recursion depth" errors when parsing
2583 programs with very long string literals.
2584
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002585Internals
2586
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002587- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002588 which is called when the interpreter starts up to determine where
2589 the standard library is installed. These vulnerabilities affect all
2590 previous versions of Python and can be exploited by setting very
2591 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2592 setuid Python script, although use of the wrapper in
2593 Misc/setuid-prog.c will eliminate the vulnerability.
2594
2595- Fixed garbage collection bugs in instance creation that were
2596 triggered when errors occurred during initialization. The solution,
2597 applied in cPickle and in PyInstance_New(), is to call
2598 PyObject_GC_Init() after the initialization of the object's
2599 container attributes is complete.
2600
2601- pyexpat adds definitions of PyModule_AddStringConstant and
2602 PyModule_AddObject if the Python version is less than 2.0, which
2603 provides compatibility with PyXML on Python 1.5.2.
2604
2605- If the platform has a bogus definition for LONG_BIT (the number of
2606 bits in a long), an error will be reported at compile time.
2607
2608- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2609 collection crashes and possibly other, unreported crashes.
2610
2611- Fixed a memory leak in _PyUnicode_Fini().
2612
2613Build issues
2614
2615- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002616 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002617 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002618
2619- The mmap.PAGESIZE constant is now initialized using sysconf when
2620 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2621
2622- The md5 file should now compile on all platforms.
2623
2624- The select module now compiles on platforms that do not define
2625 POLLRDNORM and related constants.
2626
2627- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002628 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002629
Jeremy Hylton10921202000-10-09 18:34:12 +00002630- BeOS: A number of changes were made to the build and installation
2631 process. ar-fake now operates on a directory of object files.
2632 dl_export.h is gone, and its macros now appear on the mwcc command
2633 line during build on PPC BeOS.
2634
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002635- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002636 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002637
2638- Cygwin: Support for shared libraries, Tkinter, and sockets.
2639
2640- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2641
2642Tools and other miscellany
2643
2644- Removed debugging prints from main used with freeze.
2645
Tim Peters46446d62000-10-09 21:19:31 +00002646- IDLE auto-indent no longer crashes when it encounters Unicode
2647 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002648
2649What's new in 2.0 beta 2 (since beta 1)?
2650========================================
2651
2652Core language, builtins, and interpreter
2653
Tim Peters482c0212000-09-26 06:33:09 +00002654- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002655 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002656
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002657- Add -h and -V command line options to print the usage message and
2658 Python version number and exit immediately.
2659
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002660- eval() and exec accept Unicode objects as code parameters.
2661
2662- getattr() and setattr() now also accept Unicode objects for the
2663 attribute name, which are converted to strings using the default
2664 encoding before lookup.
2665
2666- Multiplication on string and Unicode now does proper bounds
2667 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2668 string is too long."
2669
2670- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002671 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002672
Jeremy Hylton1b618592000-09-26 05:32:36 +00002673
2674Standard library and extensions
2675
Guido van Rossum5b08f132001-04-16 02:05:23 +00002676- socket module: the OpenSSL code now adds support for RAND_status()
2677 and EGD (Entropy Gathering Device).
2678
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002679- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002680 argument checking; it still takes no arguments.
2681
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002682- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002683
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002684- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002685
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002686- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002687
2688- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002689 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002690
2691- copy: Copy Unicode objects atomically.
2692
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002693- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002694
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002695- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002696
Fred Drake67233bc2000-09-26 16:40:27 +00002697- dbm: Add get() and setdefault() methods to dbm object. Add constant
2698 `library' to module that names the library used. Added doc strings
2699 and method names to error messages. Uses configure to determine
2700 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2701 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002702
2703- distutils: Update to version 0.9.3.
2704
2705- dl: Add several dl.RTLD_ constants.
2706
2707- fpectl: Now supported on FreeBSD.
2708
2709- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2710 found by the collector will be saved in gc.garbage. This is useful
2711 for debugging a program that creates reference cycles.
2712
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002713- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002714 of HTTP class. Do not close socket on zero-length response. Do not
2715 crash when server sends invalid content-length header.
2716
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002717- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002719- marshal: When reading a short, sign-extend on platforms where shorts
2720 are bigger than 16 bits. When reading a long, repair the unportable
2721 sign extension that was being done for 64-bit machines. (It assumed
2722 that signed right shift sign-extends.)
2723
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002724- operator: Add contains(), invert(), __invert__() as aliases for
2725 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002726
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002727- os: Add support for popen2() and popen3() on all platforms where
2728 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002729
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002730- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002731 clicking on a file in Explorer (or passing the file name to the
2732 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002733
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002734- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002735 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002736
2737- pickle: Now raises ValueError when an invalid pickle that contains
2738 a non-string repr where a string repr was expected. This behavior
2739 matches cPickle.
2740
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002741- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002742
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002743- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002744
2745- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002746 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002747 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002748
2749- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002750 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002751
2752- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002753 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002754 few cycles during startup since the first call to
2755 setdefaultencoding() will initialize the codec registry and the
2756 encodings package.
2757
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002758- socket: Support for size hint in readlines() method of object returned
2759 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002760
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002761- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002762 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002763 is followed by whitespace.
2764
Tim Petersa3a3a032000-11-30 05:22:44 +00002765- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002766
2767- struct: Check ranges for bytes and shorts.
2768
2769- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002770 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002771
2772- Tkinter: Image objects are now guaranteed to have unique ids. Set
2773 event.delta to zero if Tk version doesn't support mousewheel.
2774 Removed some debugging prints.
2775
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002776- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002777
Fred Drake67233bc2000-09-26 16:40:27 +00002778- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002779 which works around a bug in Norton AntiVirus 2000 that leads directly
2780 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002781
2782- xml: New version detection code allows PyXML to override standard
2783 XML package if PyXML version is greater than 0.6.1.
2784
Fred Drake64bb3802000-09-26 16:21:35 +00002785- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2786 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2787 tree only for nodes which are sufficiently interesting to a specific
2788 application. Does not provide the HTML-specific extensions. Still
2789 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002790
Fred Drake64bb3802000-09-26 16:21:35 +00002791- xml.sax: SAX 2 support for Python, including all the handler
2792 interfaces needed to process XML 1.0 compliant XML. Some
2793 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002794
Fred Drake64bb3802000-09-26 16:21:35 +00002795- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2796 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002797
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002798
Jeremy Hylton1b618592000-09-26 05:32:36 +00002799C API
2800
2801- Add three new convenience functions for module initialization --
2802 PyModule_AddObject(), PyModule_AddIntConstant(), and
2803 PyModule_AddStringConstant().
2804
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002805- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002806 removed and add #error to Python.h if NULL isn't defined after
2807 #include of stdio.h.
2808
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002809- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002810 backwards compatibility (at the source level) with old extensions.
2811
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002812- A wrapper API was added for signal() and sigaction(). Instead of
2813 either function, always use PyOS_getsig() to get a signal handler
2814 and PyOS_setsig() to set one. A new convenience typedef
2815 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002816
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002817- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002818 internal data buffer and size of a string object -- or the default
2819 encoded version of a Unicode object.
2820
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002821- PyString_Size() and PyString_AsString() accept Unicode objects.
2822
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002823- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002824 exists). INT_MAX and LONG_MAX will always be defined, even if
2825 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002826
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002827- PyFloat_FromString takes a second argument, pend, that was
2828 effectively useless. It is now officially useless but preserved for
2829 backwards compatibility. If the pend argument is not NULL, *pend is
2830 set to NULL.
2831
2832- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2833 for the attribute name. See note on getattr() above.
2834
2835- A few bug fixes to argument processing for Unicode.
2836 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2837 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2838 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002839 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002840
2841- Py_BuildValue accepts B format (for bgen-generated code).
2842
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002843
Jeremy Hylton1b618592000-09-26 05:32:36 +00002844Internals
2845
2846- On Unix, fix code for finding Python installation directory so that
2847 it works when argv[0] is a relative path.
2848
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002849- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002850 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002851 rather than by generating a copy of the object.
2852
Tim Peters482c0212000-09-26 06:33:09 +00002853- Several of the internal Unicode tables are much smaller now, and
2854 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002855
Jeremy Hylton97693b02000-09-26 17:42:51 +00002856- In the garbage collector: Fixed bug in collection of tuples. Fixed
2857 bug that caused some instances to be removed from the container set
2858 while they were still live. Fixed parsing in gc.set_debug() for
2859 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002860
2861- Fixed refcount problem in instance deallocation that only occurred
2862 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2863
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002864- On Windows, getpythonregpath is now protected against null data in
2865 registry key.
2866
2867- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002868 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002869
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002870
Jeremy Hylton1b618592000-09-26 05:32:36 +00002871Build and platform-specific issues
2872
2873- Better support of GNU Pth via --with-pth configure option.
2874
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002875- Python/C API now properly exposed to dynamically-loaded extension
2876 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002877
2878- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2879 Don't define MS_SYNC to be zero when it is undefined. Added missing
2880 prototypes in posixmodule.c.
2881
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002882- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002883 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002884
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002885- Fix largefile support on older NetBSD systems and OpenBSD by adding
2886 define for TELL64.
2887
2888
2889Tools and other miscellany
2890
2891- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2892
2893- freeze: The modulefinder now works with 2.0 opcodes.
2894
Tim Petersa3a3a032000-11-30 05:22:44 +00002895- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002896 Move hackery of sys.argv until after the Tk instance has been
2897 created, which allows the application-specific Tkinter
2898 initialization to be executed if present; also pass an explicit
2899 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002900
Jeremy Hylton1b618592000-09-26 05:32:36 +00002901
2902What's new in 2.0 beta 1?
2903=========================
2904
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002905Source Incompatibilities
2906------------------------
2907
2908None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2909such as single-argument append(), connect() and bind(), and changes to
2910str(long) and repr(float).
2911
2912
2913Binary Incompatibilities
2914------------------------
2915
2916- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2917with Python 2.0; these extensions will have to be rebuilt for Python
29182.0.
2919
2920- On Windows, attempting to import a third party extension built for
2921Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2922can do about this. Check your PYTHONPATH environment variable!
2923
2924- Python bytecode files (*.pyc and *.pyo) are not compatible between
2925releases.
2926
2927
2928Overview of Changes Since 1.6
2929-----------------------------
2930
2931There are many new modules (including brand new XML support through
2932the xml package, and i18n support through the gettext module); a list
2933of all new modules is included below. Lots of bugs have been fixed.
2934
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002935The process for making major new changes to the language has changed
2936since Python 1.6. Enhancements must now be documented by a Python
2937Enhancement Proposal (PEP) before they can be accepted.
2938
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002939There are several important syntax enhancements, described in more
2940detail below:
2941
2942 - Augmented assignment, e.g. x += 1
2943
2944 - List comprehensions, e.g. [x**2 for x in range(10)]
2945
2946 - Extended import statement, e.g. import Module as Name
2947
2948 - Extended print statement, e.g. print >> file, "Hello"
2949
2950Other important changes:
2951
2952 - Optional collection of cyclical garbage
2953
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002954Python Enhancement Proposal (PEP)
2955---------------------------------
2956
2957PEP stands for Python Enhancement Proposal. A PEP is a design
2958document providing information to the Python community, or describing
2959a new feature for Python. The PEP should provide a concise technical
2960specification of the feature and a rationale for the feature.
2961
2962We intend PEPs to be the primary mechanisms for proposing new
2963features, for collecting community input on an issue, and for
2964documenting the design decisions that have gone into Python. The PEP
2965author is responsible for building consensus within the community and
2966documenting dissenting opinions.
2967
2968The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002969
2970Augmented Assignment
2971--------------------
2972
2973This must have been the most-requested feature of the past years!
2974Eleven new assignment operators were added:
2975
Guido van Rossume905e952000-09-05 12:42:46 +00002976 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002977
2978For example,
2979
2980 A += B
2981
2982is similar to
2983
2984 A = A + B
2985
2986except that A is evaluated only once (relevant when A is something
2987like dict[index].attr).
2988
2989However, if A is a mutable object, A may be modified in place. Thus,
2990if A is a number or a string, A += B has the same effect as A = A+B
2991(except A is only evaluated once); but if a is a list, A += B has the
2992same effect as A.extend(B)!
2993
2994Classes and built-in object types can override the new operators in
2995order to implement the in-place behavior; the not-in-place behavior is
2996used automatically as a fallback when an object doesn't implement the
2997in-place behavior. For classes, the method name is derived from the
2998method name for the corresponding not-in-place operator by inserting
2999an 'i' in front of the name, e.g. __iadd__ implements in-place
3000__add__.
3001
3002Augmented assignment was implemented by Thomas Wouters.
3003
3004
3005List Comprehensions
3006-------------------
3007
3008This is a flexible new notation for lists whose elements are computed
3009from another list (or lists). The simplest form is:
3010
3011 [<expression> for <variable> in <sequence>]
3012
Guido van Rossum56db0952000-09-06 23:34:25 +00003013For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003014This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003015
3016You can also add a condition:
3017
3018 [<expression> for <variable> in <sequence> if <condition>]
3019
3020For example, [w for w in words if w == w.lower()] would yield the list
3021of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003022than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003023
3024You can also have nested for loops and more than one 'if' clause. For
3025example, here's a function that flattens a sequence of sequences::
3026
3027 def flatten(seq):
3028 return [x for subseq in seq for x in subseq]
3029
3030 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3031
3032This prints
3033
3034 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3035
3036List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003037Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003038
3039
3040Extended Import Statement
3041-------------------------
3042
3043Many people have asked for a way to import a module under a different
3044name. This can be accomplished like this:
3045
3046 import foo
3047 bar = foo
3048 del foo
3049
3050but this common idiom gets old quickly. A simple extension of the
3051import statement now allows this to be written as follows:
3052
3053 import foo as bar
3054
3055There's also a variant for 'from ... import':
3056
3057 from foo import bar as spam
3058
3059This also works with packages; e.g. you can write this:
3060
3061 import test.regrtest as regrtest
3062
3063Note that 'as' is not a new keyword -- it is recognized only in this
3064context (this is only possible because the syntax for the import
3065statement doesn't involve expressions).
3066
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003067Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003068
3069
3070Extended Print Statement
3071------------------------
3072
3073Easily the most controversial new feature, this extension to the print
3074statement adds an option to make the output go to a different file
3075than the default sys.stdout.
3076
3077For example, to write an error message to sys.stderr, you can now
3078write:
3079
3080 print >> sys.stderr, "Error: bad dog!"
3081
3082As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003083evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003084
3085 print >> None, "Hello world"
3086
3087is equivalent to
3088
3089 print "Hello world"
3090
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003091Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003092
3093
3094Optional Collection of Cyclical Garbage
3095---------------------------------------
3096
3097Python is now equipped with a garbage collector that can hunt down
3098cyclical references between Python objects. It's no replacement for
3099reference counting; in fact, it depends on the reference counts being
3100correct, and decides that a set of objects belong to a cycle if all
3101their reference counts can be accounted for from their references to
3102each other. This devious scheme was first proposed by Eric Tiedemann,
3103and brought to implementation by Neil Schemenauer.
3104
3105There's a module "gc" that lets you control some parameters of the
3106garbage collection. There's also an option to the configure script
3107that lets you enable or disable the garbage collection. In 2.0b1,
3108it's on by default, so that we (hopefully) can collect decent user
3109experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003110performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003111off by default in the final 2.0 release.
3112
3113
3114Smaller Changes
3115---------------
3116
3117A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3118map(None, seq1, seq2, ...) when the sequences have the same length;
3119i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3120the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003121zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003122
3123sys.version_info is a tuple (major, minor, micro, level, serial).
3124
3125Dictionaries have an odd new method, setdefault(key, default).
3126dict.setdefault(key, default) returns dict[key] if it exists; if not,
3127it sets dict[key] to default and returns that value. Thus:
3128
3129 dict.setdefault(key, []).append(item)
3130
3131does the same work as this common idiom:
3132
3133 if not dict.has_key(key):
3134 dict[key] = []
3135 dict[key].append(item)
3136
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003137There are two new variants of SyntaxError that are raised for
3138indentation-related errors: IndentationError and TabError.
3139
3140Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3141escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003142
3143The limits on the size of expressions and file in Python source code
3144have been raised from 2**16 to 2**32. Previous versions of Python
3145were limited because the maximum argument size the Python VM accepted
3146was 2**16. This limited the size of object constructor expressions,
3147e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3148limit was raised thanks to a patch by Charles Waldman that effectively
3149fixes the problem. It is now much more likely that you will be
3150limited by available memory than by an arbitrary limit in Python.
3151
3152The interpreter's maximum recursion depth can be modified by Python
3153programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3154limit is the maximum number of recursive calls that can be made by
3155Python code. The limit exists to prevent infinite recursion from
3156overflowing the C stack and causing a core dump. The default value is
31571000. The maximum safe value for a particular platform can be found
3158by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003159
3160New Modules and Packages
3161------------------------
3162
3163atexit - for registering functions to be called when Python exits.
3164
3165imputil - Greg Stein's alternative API for writing custom import
3166hooks.
3167
3168pyexpat - an interface to the Expat XML parser, contributed by Paul
3169Prescod.
3170
3171xml - a new package with XML support code organized (so far) in three
3172subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3173would fill a volume. There's a special feature whereby a
3174user-installed package named _xmlplus overrides the standard
3175xmlpackage; this is intended to give the XML SIG a hook to distribute
3176backwards-compatible updates to the standard xml package.
3177
3178webbrowser - a platform-independent API to launch a web browser.
3179
3180
Guido van Rossume905e952000-09-05 12:42:46 +00003181Changed Modules
3182---------------
3183
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003184array -- new methods for array objects: count, extend, index, pop, and
3185remove
3186
3187binascii -- new functions b2a_hex and a2b_hex that convert between
3188binary data and its hex representation
3189
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003190calendar -- Many new functions that support features including control
3191over which day of the week is the first day, returning strings instead
3192of printing them. Also new symbolic constants for days of week,
3193e.g. MONDAY, ..., SUNDAY.
3194
3195cgi -- FieldStorage objects have a getvalue method that works like a
3196dictionary's get method and returns the value attribute of the object.
3197
3198ConfigParser -- The parser object has new methods has_option,
3199remove_section, remove_option, set, and write. They allow the module
3200to be used for writing config files as well as reading them.
3201
3202ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003203optionally support the RFC 959 REST command.
3204
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003205gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003206
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003207httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3208the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003209
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003210locale -- implement getdefaultlocale for Win32 and Macintosh
3211
3212marshal -- no longer dumps core when marshaling deeply nested or
3213recursive data structures
3214
3215os -- new functions isatty, seteuid, setegid, setreuid, setregid
3216
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003217os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3218support under Unix.
3219
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003220os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003221
3222os.path -- fix semantics of os.path.commonprefix
3223
3224smtplib -- support for sending very long messages
3225
3226socket -- new function getfqdn()
3227
3228readline -- new functions to read, write and truncate history files.
3229The readline section of the library reference manual contains an
3230example.
3231
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003232select -- add interface to poll system call
3233
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003234shutil -- new copyfileobj function
3235
3236SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3237HTTP server.
3238
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003239Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003240
3241urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003242e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003243
3244whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003245
3246
3247Obsolete Modules
3248----------------
3249
3250None. However note that 1.6 made a whole slew of modules obsolete:
3251stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3252poly, zmod, strop, util, whatsound.
3253
3254
3255Changed, New, Obsolete Tools
3256----------------------------
3257
Tim Peters8b092332000-09-05 20:15:25 +00003258None.
Guido van Rossume905e952000-09-05 12:42:46 +00003259
3260
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003261C-level Changes
3262---------------
3263
3264Several cleanup jobs were carried out throughout the source code.
3265
3266All C code was converted to ANSI C; we got rid of all uses of the
3267Py_PROTO() macro, which makes the header files a lot more readable.
3268
3269Most of the portability hacks were moved to a new header file,
3270pyport.h; several other new header files were added and some old
3271header files were removed, in an attempt to create a more rational set
3272of header files. (Few of these ever need to be included explicitly;
3273they are all included by Python.h.)
3274
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003275Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003276and Win64, especially for the new Intel Itanium processor. Mick also
3277added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003278
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003279The C APIs to return an object's size have been update to consistently
3280use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3281previous versions, the abstract interfaces used PyXXX_Length and the
3282concrete interfaces used PyXXX_Size. The old names,
3283e.g. PyObject_Length, are still available for backwards compatibility
3284at the API level, but are deprecated.
3285
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003286The PyOS_CheckStack function has been implemented on Windows by
3287Fredrik Lundh. It prevents Python from failing with a stack overflow
3288on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003289
3290The GC changes resulted in creation of two new slots on object,
3291tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003292the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003293
3294The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003295C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003296
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003297PyErr_Format has been updated to automatically calculate the size of
3298the buffer needed to hold the formatted result string. This change
3299prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003300
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003301New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003302
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003303PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3304that are the same as their non-Ex counterparts except they take an
3305extra flag argument that tells them to close the file when done.
3306
3307XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003308
Tim Peters8b092332000-09-05 20:15:25 +00003309
3310Windows Changes
3311---------------
3312
3313New popen2/popen3/peopen4 in os module (see Changed Modules above).
3314
3315os.popen is much more usable on Windows 95 and 98. See Microsoft
3316Knowledge Base article Q150956. The Win9x workaround described there
3317is implemented by the new w9xpopen.exe helper in the root of your
3318Python installation. Note that Python uses this internally; it is not
3319a standalone program.
3320
3321Administrator privileges are no longer required to install Python
3322on Windows NT or Windows 2000. If you have administrator privileges,
3323Python's registry info will be written under HKEY_LOCAL_MACHINE.
3324Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003325under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003326uses of Python, but will prevent some advanced uses from working
3327(for example, running a Python script as an NT service, or possibly
3328from CGI).
3329
3330[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3331installer; instead, it installs the needed Tcl/Tk files directly in the
3332Python directory. If you already have a Tcl/Tk installation, this
3333wastes some disk space (about 4 Megs) but avoids problems with
3334conflicting Tcl/Tk installations, and makes it much easier for Python
3335to ensure that Tcl/Tk can find all its files.
3336
3337[This was new in 1.6] The Windows installer now installs by default in
3338\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3339
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003340
3341Updates to the changes between 1.5.2 and 1.6
3342--------------------------------------------
3343
3344The 1.6 NEWS file can't be changed after the release is done, so here
3345is some late-breaking news:
3346
3347New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3348and changes to getlocale() and setlocale().
3349
3350The new module is now enabled per default.
3351
3352It is not true that the encodings codecs cannot be used for normal
3353strings: the string.encode() (which is also present on 8-bit strings
3354!) allows using them for 8-bit strings too, e.g. to convert files from
3355cp1252 (Windows) to latin-1 or vice-versa.
3356
3357Japanese codecs are available from Tamito KAJIYAMA:
3358http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3359
3360
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003361======================================================================