blob: d3ed145ac2d0decaf16e769eb64d51c571b188d9 [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 Rossum49042042002-04-13 00:59:05 +00009- String methods lstrip(), rstrip() and strip() now take an optional
10 argument that specifies the characters to strip. For example,
11 "Foo!!!?!?!?".rstrip("?!") -> "Foo".
12
Guido van Rossumc69343b2002-04-12 19:22:48 +000013- Added a new dict method pop(key). This removes and returns the
14 value corresponding to key. [SF patch #539949]
15
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000016- Changed new-style class instantiation so that when C's __new__
17 method returns something that's not a C instance, its __init__ is
18 not called. [SF bug #537450]
19
Guido van Rossum181e41a2002-04-06 00:23:25 +000020- Fixed super() to work correctly with class methods. [SF bug #535444]
21
Guido van Rossum47834462002-04-04 15:21:33 +000022- A new built-in type, bool, has been added, as well as built-in
23 names for its two values, True and False. Comparisons and sundry
24 other operations that return a truth value have been changed to
25 return a bool instead. Read PEP 285 for an explanantion of why this
26 is backward compatible.
27
Guido van Rossum95b62a62002-03-29 01:07:24 +000028- Fixed two bugs reported as SF #535905: under certain conditions,
29 deallocating a deeply nested structure could cause a segfault in the
30 garbage collector, due to interaction with the "trashcan" code;
31 access to the current frame during destruction of a local variable
32 could access a pointer to freed memory.
33
Neil Schemenauer9d50d132002-03-22 17:06:59 +000034- The optional object allocator has been enabled by default.
35
Guido van Rossum8c842552002-03-14 23:05:54 +000036- If you try to pickle an instance of a class that has __slots__ but
37 doesn't define or override __getstate__, a TypeError is now raised.
38 This is done by adding a bozo __getstate__ to the class that always
39 raises TypeError. (Before, this would appear to be pickled, but the
40 state of the slots would be lost.)
41
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000042- PyErr_Display will provide file and line information for all exceptions
43 that have an attribute print_file_and_line, not just SyntaxErrors.
44
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000045- The UTF-8 codec will now encode and decode Unicode surrogates
46 correctly and without raising exceptions for unpaired ones.
47
Neal Norwitz649b7592002-01-01 19:07:13 +000048- file.xreadlines() now raises a ValueError if the file is closed:
49 Previously, an xreadlines object was returned which would raise
50 a ValueError when the xreadlines.next() method was called.
51
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000052- posix.killpg has been added where available.
53
Neal Norwitz0c766a02002-03-27 13:03:09 +000054- sys.exit() inadvertantly allowed more than one argument.
55 An exception will now be raised if more than one argument is used.
56
Tim Petersaf8446f2001-12-21 21:36:50 +000057Extension modules
58
Martin v. Löwis2e64c342002-03-27 18:49:02 +000059- The locale module now exposes the C library's gettext interface.
60
Tim Petersfbf74f22002-03-14 19:06:01 +000061- A security hole ("double free") was found in zlib-1.1.3, a popular
62 third party compression library used by some Python modules. The
63 hole was quickly plugged in zlib-1.1.4, and the Windows build of
64 Python now ships with zlib-1.1.4.
65
Martin v. Löwis688357e2002-04-08 21:28:20 +000066- pwd, grp, and resource return enhanced tuples now, with symbolic
67 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +000068
Martin v. Löwis99866332002-03-01 10:27:01 +000069- array.array is now a type object. A new format character
70 'u' indicates Py_UNICODE arrays. For those, .tounicode and
71 .fromunicode methods are available. Arrays now support __iadd__
72 and __imul__.
73
Neal Norwitze790eae2002-01-01 21:14:12 +000074- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000075 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
76 is called.
77
Tim Petersaf8446f2001-12-21 21:36:50 +000078Library
79
Marc-André Lemburg4179a012002-04-05 12:15:05 +000080- The UTF-16, -LE and -BE now raise a NotImplementedError
81 for all calls to .readline(). Previously, they used to just
82 produce garbage or fail with an encoding error -- UTF-16 is
83 a 2-byte encoding and the C lib's line reading APIs don't
84 work well with these.
85
Martin v. Löwis5c137c22002-03-18 12:44:08 +000086- compileall now supports quiet operation.
87
Martin v. Löwis587c98c2002-03-17 18:37:22 +000088- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
89 connections.
90
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000091- socket module: the SSL support was broken out of the main
92 _socket module C helper and placed into a new _ssl helper
93 which now gets imported by socket.py if available and working.
94
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000095- encodings package: added aliases for all supported IANA character
96 sets
97
Guido van Rossum606fe4e2001-12-28 20:57:14 +000098- ftplib: to safeguard the user's privacy, anonymous login will use
99 "anonymous@" as default password, rather than the real user and host
100 name.
101
Fred Drake36736122002-01-10 13:50:31 +0000102- webbrowser: tightened up the command passed to os.system() so that
103 arbitrary shell code can't be executed because a bogus URL was
104 passed in.
105
Tim Peters11bd9942002-02-01 00:52:29 +0000106- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000107 gettext.find an optional all argument. Translations will now fallback
108 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000109
Martin v. Löwis9668b932002-01-12 11:27:42 +0000110- distutils bdist commands now offer a --skip-build option.
111
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000112- warnings.warn now accepts a Warning instance as first argument.
113
Fred Drakefed7e852002-04-04 19:36:15 +0000114- The xml.sax.expatreader.ExpatParser class will no longer create
115 circular references by using itself as the locator that gets passed
116 to the content handler implementation. [SF bug #535474]
117
Tim Petersaf8446f2001-12-21 21:36:50 +0000118Tools/Demos
119
Marc-André Lemburg46260092002-04-04 16:17:11 +0000120- freeze.py now produces binaries which can import shared modules,
121 unlike before when this failed due to missing symbol exports in
122 the generated binary.
123
Tim Petersaf8446f2001-12-21 21:36:50 +0000124Build
125
Martin v. Löwis1142de32002-03-29 16:28:31 +0000126- On Unix, a shared libpython2.3.so can be created with --enable-shared.
127
Tim Peters8deda702002-03-30 10:06:07 +0000128- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
129 preprocessor symbols were eliminated. The internal decisions they
130 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000131
Tim Petersaf8446f2001-12-21 21:36:50 +0000132C API
133
Neil Schemenauer9344b142002-04-12 23:00:08 +0000134- The type of tp_free has been changed from "void (*)(PyObject *)" to
135 "void (*)(void *)".
136
137- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
138
Guido van Rossum0986d822002-04-08 01:38:42 +0000139- A type can now inherit its metatype from its base type. Previously,
140 when PyType_Ready() was called, if ob_type was found to be NULL, it
141 was always set to &PyType_Type; now it is set to base->ob_type,
142 where base is tp_base, defaulting to &PyObject_Type.
143
144- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
145
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000146- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
147 functions will be allocated using pymalloc if it is enabled. These
148 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
149 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
150 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
151 PyCore_* family of APIs have been removed.
152
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000153- The "u#" parser marker will now pass through Unicode object as-is
154 without going through the buffer API.
155
Martin v. Löwis7198a522002-01-01 19:59:11 +0000156- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
157
Tim Peters10a3bb52001-12-25 19:07:38 +0000158- An old #define of ANY as void has been removed from pyport.h. This
159 hasn't been used since Python's pre-ANSI days, and the #define has
160 been marked as obsolete since then. SF bug 495548 says it created
161 conflicts with other packages, so keeping it around wasn't harmless.
162
Tim Petersaf8446f2001-12-21 21:36:50 +0000163- Because Python's magic number scheme broke on January 1st, we decided
164 to stop Python development. Thanks for all the fish!
165
Tim Petersfb05db22002-03-11 00:24:00 +0000166- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000167 scheme to a new one. See Python/import.c for details.
168
Tim Petersaf8446f2001-12-21 21:36:50 +0000169New platforms
170
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000171- GNU/Hurd is now supported.
172
Tim Petersaf8446f2001-12-21 21:36:50 +0000173Tests
174
175Windows
176
Guido van Rossum181e41a2002-04-06 00:23:25 +0000177- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
178
Tim Peters33187922002-04-04 20:02:04 +0000179- The installer now installs Start menu shortcuts under (the local
180 equivalent of) "All Users" when doing an Admin install.
181
Tim Petersfb05db22002-03-11 00:24:00 +0000182- file.truncate([newsize]) now works on Windows for all newsize values.
183 It used to fail if newsize didn't fit in 32 bits, reflecting a
184 limitation of MS _chsize (which is no longer used).
185
Tim Petersab034fa2002-02-01 11:27:43 +0000186- os.waitpid() is now implemented for Windows, and can be used to block
187 until a specified process exits. This is similar to, but not exactly
188 the same as, os.waitpid() on POSIX systems. If you're waiting for
189 a specific process whose pid was obtained from one of the spawn()
190 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000191 See the docs for details. The docs were changed to clarify that
192 spawn functions return, and waitpid requires, a process handle on
193 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000194
Tim Peters11bd9942002-02-01 00:52:29 +0000195- New tempfile.TemporaryFile implementation for Windows: this doesn't
196 need a TemproraryFileWrapper wrapper anymore, and should be immune
197 to a nasty problem: before 2.3, if you got a temp file on Windows, it
198 got wrapped in an object whose close() method first closed the
199 underlying file, then deleted the file. This usually worked fine.
200 However, the spawn family of functions on Windows create (at a low C
201 level) the same set of open files in the spawned process Q as were
202 open in the spawning process P. If a temp file f was among them, then
203 doing f.close() in P first closed P's C-level file handle on f, but Q's
204 C-level file handle on f remained open, so the attempt in P to delete f
205 blew up with a "Permission denied" error (Windows doesn't allow
206 deleting open files). This was surprising, subtle, and difficult to
207 work around.
208
209- The os module now exports all the symbolic constants usable with the
210 low-level os.open() on Windows: the new constants in 2.3 are
211 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
212 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
213 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
214 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
215 (so specify both if you want both; note that neither is useful unless
216 specified with O_CREAT too).
217
Tim Petersaf8446f2001-12-21 21:36:50 +0000218Mac
219
220
Tim Peters909c0912001-12-14 23:16:18 +0000221What's New in Python 2.2 final?
222Release date: 21-Dec-2001
223===============================
224
225Type/class unification and new-style classes
226
Barry Warsaw52acb492001-12-21 20:04:22 +0000227- pickle.py, cPickle: allow pickling instances of new-style classes
228 with a custom metaclass.
229
Tim Peters909c0912001-12-14 23:16:18 +0000230Core and builtins
231
Barry Warsaw52acb492001-12-21 20:04:22 +0000232- weakref proxy object: when comparing, unwrap both arguments if both
233 are proxies.
234
Tim Peters909c0912001-12-14 23:16:18 +0000235Extension modules
236
Barry Warsaw52acb492001-12-21 20:04:22 +0000237- binascii.b2a_base64(): fix a potential buffer overrun when encoding
238 very short strings.
239
240- cPickle: the obscure "fast" mode was suspected of causing stack
241 overflows on the Mac. Hopefully fixed this by setting the recursion
242 limit much smaller. If the limit is too low (it only affects
243 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
244 when compiling cPickle.c (or in pyconfig.h).
245
Tim Peters909c0912001-12-14 23:16:18 +0000246Library
247
Barry Warsaw52acb492001-12-21 20:04:22 +0000248- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
249 close or delete time).
250
251- rfc822.py: fixed a bug where the address '<>' was converted to None
252 instead of an empty string (also fixes the email.Utils module).
253
254- xmlrpclib.py: version 1.0.0; uses precision for doubles.
255
256- test suite: the pickle and cPickle tests were not executing any code
257 when run from the standard regresssion test.
258
Tim Peters909c0912001-12-14 23:16:18 +0000259Tools/Demos
260
261Build
262
263C API
264
265New platforms
266
267Tests
268
269Windows
270
Barry Warsaw52acb492001-12-21 20:04:22 +0000271- distutils package: fixed broken Windows installers (bdist_wininst).
272
273- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
274 instances are deleted at process exit time.
275
276- socket.py: prevent mysterious warnings when socket instances are
277 deleted at process exit time.
278
279- posixmodule.c: fix a Windows crash with stat() of a filename ending
280 in backslash.
281
Tim Peters909c0912001-12-14 23:16:18 +0000282Mac
283
Barry Warsaw52acb492001-12-21 20:04:22 +0000284- The Carbon toolbox modules have been upgraded to Universal Headers
285 3.4, and experimental CoreGraphics and CarbonEvents modules have
286 been added. All only for framework-enabled MacOSX.
287
Tim Peters909c0912001-12-14 23:16:18 +0000288
Tim Peters6272dfd2001-12-13 19:34:00 +0000289What's New in Python 2.2c1?
290Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000291===========================
292
293Type/class unification and new-style classes
294
Barry Warsaw06557452001-12-14 20:47:12 +0000295- Guido's tutorial introduction to the new type/class features has
296 been extensively updated. See
297
298 http://www.python.org/2.2/descrintro.html
299
300 That remains the primary documentation in this area.
301
Guido van Rossum33bab012001-12-05 22:45:48 +0000302- Fixed a leak: instance variables declared with __slots__ were never
303 deleted!
304
Guido van Rossum4b800852001-12-03 00:54:52 +0000305- The "delete attribute" method of descriptor objects is called
306 __delete__, not __del__. In previous releases, it was mistakenly
307 called __del__, which created an unfortunate overloading condition
308 with finalizers. (The "get attribute" and "set attribute" methods
309 are still called __get__ and __set__, respectively.)
310
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000311- Some subtle issues with the super built-in were fixed:
312
313 (a) When super itself is subclassed, its __get__ method would still
314 return an instance of the base class (i.e., of super).
315
316 (b) super(C, C()).__class__ would return C rather than super. This
317 is confusing. To fix this, I decided to change the semantics of
318 super so that it only applies to code attributes, not to data
319 attributes. After all, overriding data attributes is not
320 supported anyway.
321
322 (c) The __get__ method didn't check whether the argument was an
323 instance of the type used in creation of the super instance.
324
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000325- Previously, hash() of an instance of a subclass of a mutable type
326 (list or dictionary) would return some value, rather than raising
327 TypeError. This has been fixed. Also, directly calling
328 dict.__hash__ and list.__hash__ now raises the same TypeError
329 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000330
Guido van Rossumd331cb52001-12-05 19:46:42 +0000331- New-style objects now support deleting their __dict__. This is for
332 all intents and purposes equivalent to assigning a brand new empty
333 dictionary, but saves space if the object is not used further.
334
Tim Petersb3c9af12001-11-17 00:21:57 +0000335Core and builtins
336
Tim Peters3caca232001-12-06 06:23:26 +0000337- -Qnew now works as documented in PEP 238: when -Qnew is passed on
338 the command line, all occurrences of "/" use true division instead
339 of classic division. See the PEP for details. Note that "all"
340 means all instances in library and 3rd-party modules, as well as in
341 your own code. As the PEP says, -Qnew is intended for use only in
342 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000343 Note that test_coercion.py in the standard Python test suite fails
344 under -Qnew; this is expected, and won't be repaired until true
345 division becomes the default (in the meantime, test_coercion is
346 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000347
Fred Drake6c01e252001-12-14 17:08:12 +0000348- complex() now only allows the first argument to be a string
349 argument, and raises TypeError if either the second arg is a string
350 or if the second arg is specified when the first is a string.
351
Tim Petersb3c9af12001-11-17 00:21:57 +0000352Extension modules
353
Martin v. Löwis560da622001-11-24 09:24:51 +0000354- gc.get_referents was renamed to gc.get_referrers.
355
Tim Petersb3c9af12001-11-17 00:21:57 +0000356Library
357
Tim Peters25059d32001-12-07 20:35:43 +0000358- Functions in the os.spawn() family now release the global interpreter
359 lock around calling the platform spawn. They should always have done
360 this, but did not before 2.2c1. Multithreaded programs calling
361 an os.spawn function with P_WAIT will no longer block all Python threads
362 until the spawned program completes. It's possible that some programs
363 relies on blocking, although more likely by accident than by design.
364
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000365- webbrowser defaults to netscape.exe on OS/2 now.
366
Martin v. Löwis652e1912001-11-25 14:50:56 +0000367- Tix.ResizeHandle exposes detach_widget, hide, and show.
368
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000369- The charset alias windows_1252 has been added.
370
Barry Warsaw06557452001-12-14 20:47:12 +0000371- types.StringTypes is a tuple containing the defined string types;
372 usually this will be (str, unicode), but if Python was compiled
373 without Unicode support it will be just (str,).
374
375- The pulldom and minidom modules were synchronized to PyXML.
376
Tim Petersb3c9af12001-11-17 00:21:57 +0000377Tools/Demos
378
Barry Warsaw06557452001-12-14 20:47:12 +0000379- A new script called Tools/scripts/google.py was added, which fires
380 off a search on Google.
381
Tim Petersb3c9af12001-11-17 00:21:57 +0000382Build
383
Barry Warsaw06557452001-12-14 20:47:12 +0000384- Note that release builds of Python should arrange to define the
385 preprocessor symbol NDEBUG on the command line (or equivalent).
386 In the 2.2 pre-release series we tried to define this by magic in
387 Python.h instead, but it proved to cause problems for extension
388 authors. The Unix, Windows and Mac builds now all define NDEBUG in
389 release builds via cmdline (or equivalent) instead. Ports to
390 other platforms should do likewise.
391
Jack Jansen1999ef42001-12-06 21:47:20 +0000392- It is no longer necessary to use --with-suffix when building on a
393 case-insensitive file system (such as Mac OS X HFS+). In the build
394 directory an extension is used, but not in the installed python.
395
Tim Petersb3c9af12001-11-17 00:21:57 +0000396C API
397
Tim Petersf582b822001-12-11 18:51:08 +0000398- New function PyDict_MergeFromSeq2() exposes the builtin dict
399 constructor's logic for updating a dictionary from an iterable object
400 producing key-value pairs.
401
Tim Peterscffed4b2001-11-29 03:26:37 +0000402- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000403 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000404 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
405 dump core in some bad cases. This has been repaired. As a result,
406 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
407 previously went unchallenged.
408
Tim Petersb3c9af12001-11-17 00:21:57 +0000409New platforms
410
411Tests
412
413Windows
414
415Mac
416
Jack Jansenffa260f2001-12-06 21:14:00 +0000417- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
418 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000419
Barry Warsaw06557452001-12-14 20:47:12 +0000420- Changed logic for finding python home in Mac OS X framework Pythons.
421 Now sys.executable points to the executable again, in stead of to
422 the shared library. The latter is used only for locating the python
423 home.
424
425
Tim Peters84362bc2001-10-19 17:55:30 +0000426What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000427Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000428===========================
429
430Type/class unification and new-style classes
431
Guido van Rossum3d27df02001-11-15 20:27:54 +0000432- Multiple inheritance mixing new-style and classic classes in the
433 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000434
435 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000436 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000437
438 The MRO (method resolution order) for each base class is respected
439 according to its kind, but the MRO for the derived class is computed
440 using new-style MRO rules if any base clase is a new-style class.
441 This needs to be documented.
442
Tim Petersa427a2b2001-10-29 22:25:45 +0000443- The new builtin dictionary() constructor, and dictionary type, have
444 been renamed to dict. This reflects a decade of common usage.
445
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000446- dict() now accepts an iterable object producing 2-sequences. For
447 example, dict(d.items()) == d for any dictionary d. The argument,
448 and the elements of the argument, can be any iterable objects.
449
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000450- New-style classes can now have a __del__ method, which is called
451 when the instance is deleted (just like for classic classes).
452
Guido van Rossum12d955c2001-10-26 14:56:06 +0000453- Assignment to object.__dict__ is now possible, for objects that are
454 instances of new-style classes that have a __dict__ (unless the base
455 class forbids it).
456
Guido van Rossumc8e56452001-10-22 00:43:43 +0000457- Methods of built-in types now properly check for keyword arguments
458 (formerly these were silently ignored). The only built-in methods
459 that take keyword arguments are __call__, __init__ and __new__.
460
Guido van Rossum86443212001-10-27 22:28:54 +0000461- The socket function has been converted to a type; see below.
462
Tim Peters84362bc2001-10-19 17:55:30 +0000463Core and builtins
464
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000465- Assignment to __debug__ raises SyntaxError at compile-time. This
466 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000467 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000468
Guido van Rossum12d955c2001-10-26 14:56:06 +0000469- Clarified the error messages for unsupported operands to an operator
470 (like 1 + '').
471
Tim Peters84362bc2001-10-19 17:55:30 +0000472Extension modules
473
Tim Peters5ebfd362001-11-13 23:11:19 +0000474- mmap has a new keyword argument, "access", allowing a uniform way for
475 both Windows and Unix users to create read-only, write-through and
476 copy-on-write memory mappings. This was previously possible only on
477 Unix. A new keyword argument was required to support this in a
478 uniform way because the mmap() signuatures had diverged across
479 platforms. Thanks to Jay T Miller for repairing this!
480
Tim Peters169ded02001-11-03 19:57:21 +0000481- By default, the gc.garbage list now contains only those instances in
482 unreachable cycles that have __del__ methods; in 2.1 it contained all
483 instances in unreachable cycles. "Instances" here has been generalized
484 to include instances of both new-style and old-style classes.
485
Guido van Rossum12d955c2001-10-26 14:56:06 +0000486- The socket module defines a new method for socket objects,
487 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000488 send() until all data has been sent. Also, the socket function has
489 been converted to a subclassable type, like list and tuple (etc.)
490 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000491
492- Various bugfixes to the curses module. There is now a test suite
493 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000494
Guido van Rossum692adf12001-10-30 03:03:03 +0000495- binascii.b2a_base64 no longer places an arbitrary restriction of 57
496 bytes on its input.
497
Tim Peters84362bc2001-10-19 17:55:30 +0000498Library
499
Tim Peters5ebfd362001-11-13 23:11:19 +0000500- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000501 convenience function.
502
Tim Peters75335872001-11-03 19:35:43 +0000503- Symbolic group names in regular expressions must be unique. For
504 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
505 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000506 Python 2.2 detects this error at regexp compilation time;
507 previously, the error went undetected, and results were
508 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
509 pattern.subn() methods have been rewritten in C. Also, an
510 experimental function/method finditer() has been added, which works
511 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000512
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000513- Tix exposes more commands through the classes DirSelectBox,
514 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
515 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
516 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
517
Tim Peters98791af2001-10-23 01:59:54 +0000518- Traceback objects are now scanned by cyclic garbage collection, so
519 cycles created by casual use of sys.exc_info() no longer cause
520 permanent memory leaks (provided garbage collection is enabled).
521
Guido van Rossum49192142001-10-24 20:51:44 +0000522- os.extsep -- a new variable needed by the RISCOS support. It is the
523 separator used by extensions, and is '.' on all platforms except
524 RISCOS, where it is '/'. There is no need to use this variable
525 unless you have a masochistic desire to port your code to RISCOS.
526
Barry Warsaw012852b2001-11-16 16:17:27 +0000527- mimetypes.py has optional support for non-standard, but commonly
528 found types. guess_type() and guess_extension() now accept an
529 optional `strict' flag, defaulting to true, which controls whether
530 recognize non-standard types or not. A few non-standard types we
531 know about have been added. Also, when run as a script, there are
532 new -l and -e options.
533
534- statcache is now deprecated.
535
536- email.Utils.formatdate() now produces the preferred RFC 2822 style
537 dates with numeric timezones (it used to produce obsolete dates
538 hard coded to "GMT" timezone). An optional `localtime' flag is
539 added to produce dates in the local timezone, with daylight savings
540 time properly taken into account.
541
542- In pickle and cPickle, instead of masking errors in load() by
543 transforming them into SystemError, we let the original exception
544 propagate out. Also, implement support for __safe_for_unpickling__
545 in pickle, as it already was supported in cPickle.
546
Tim Peters84362bc2001-10-19 17:55:30 +0000547Tools/Demos
548
549Build
550
Barry Warsaw012852b2001-11-16 16:17:27 +0000551- The dbm module is built using libdb1 if available. The bsddb module
552 is built with libdb3 if available.
553
554- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
555
Tim Peters84362bc2001-10-19 17:55:30 +0000556C API
557
Tim Peters1fc240e2001-10-26 05:06:50 +0000558- New function PySequence_Fast_GET_SIZE() returns the size of a non-
559 NULL result from PySequence_Fast(), more quickly than calling
560 PySequence_Size().
561
Barry Warsaw012852b2001-11-16 16:17:27 +0000562- New argument unpacking function PyArg_UnpackTuple() added.
563
564- New functions PyObject_CallFunctionObjArgs() and
565 PyObject_CallMethodObjArgs() have been added to make it more
566 convenient and efficient to call functions and methods from C.
567
568- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
569 possible that this will propagate errors it didn't before.
570
571- New function PyObject_CheckReadBuffer(), which returns true if its
572 argument supports the single-segment readable buffer interface.
573
Tim Peters84362bc2001-10-19 17:55:30 +0000574New platforms
575
Guido van Rossum86443212001-10-27 22:28:54 +0000576- We've finally confirmed that this release builds on HP-UX 11.00,
577 *with* threads, and passes the test suite.
578
Tim Peters7a33d8b2001-11-05 02:51:07 +0000579- Thanks to a series of patches from Michael Muller, Python may build
580 again under OS/2 Visual Age C++.
581
Guido van Rossum49192142001-10-24 20:51:44 +0000582- Updated RISCOS port by Dietmar Schwertberger.
583
Tim Peters84362bc2001-10-19 17:55:30 +0000584Tests
585
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000586- Added a test script for the curses module. It isn't run automatically;
587 regrtest.py must be run with '-u curses' to enable it.
588
Tim Peters84362bc2001-10-19 17:55:30 +0000589Windows
590
Barry Warsaw012852b2001-11-16 16:17:27 +0000591Mac
592
593- PythonScript has been moved to unsupported and is slated to be
594 removed completely in the next release.
595
596- It should now be possible to build applets that work on both OS9 and
597 OSX.
598
599- The core is now linked with CoreServices not Carbon; as a side
600 result, default 8bit encoding on OSX is now ASCII.
601
602- Python should now build on OSX 10.1.1
603
Tim Peters84362bc2001-10-19 17:55:30 +0000604
Tim Petersabf925f2001-09-28 21:53:42 +0000605What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000606Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000607===========================
608
609Type/class unification and new-style classes
610
Guido van Rossum687ae002001-10-15 22:03:32 +0000611- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000612 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000613 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000614 remains: the __dict__ of a new-style class is a read-only proxy; you
615 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000616 __defined__ attribute of new-style types no longer exists, for lack
617 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000618 future a __cache__ may be resurrected with a similar function, if I
619 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000620
Tim Peters1c9ca872001-10-04 06:43:12 +0000621- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
622 always returned None, even when there was a class docstring).
623
624- doctest now finds and runs docstrings attached to new-style classes,
625 class methods, static methods, and properties.
626
Guido van Rossum9074ef62001-10-16 21:34:49 +0000627Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000628
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000629- A very subtle syntactical pitfall in list comprehensions was fixed.
630 For example: [a+b for a in 'abc', for b in 'def']. The comma in
631 this example is a mistake. Previously, this would silently let 'a'
632 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
633 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
634 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
635 Note that [a for a in <singleton>] is a convoluted way to say
636 [<singleton>] anyway, so it's not like any expressiveness is lost.
637
Guido van Rossum9074ef62001-10-16 21:34:49 +0000638- getattr(obj, name, default) now only catches AttributeError, as
639 documented, rather than returning the default value for all
640 exceptions (which could mask bugs in a __getattr__ hook, for
641 example).
642
Fred Drakecb7a6b52001-10-22 18:41:51 +0000643- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000644 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000645 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000646 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000647
Guido van Rossum1c486092001-10-19 02:05:35 +0000648- unicode(obj) now behaves more like str(obj), accepting arbitrary
649 objects, and calling a __unicode__ method if it exists.
650 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000651 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000652
Barry Warsawf6fb1712001-10-19 05:35:40 +0000653- isinstance() now allows any object as the first argument and a
654 class, a type or something with a __bases__ tuple attribute for the
655 second argument. The second argument may also be a tuple of a
656 class, type, or something with __bases__, in which case isinstance()
657 will return true if the first argument is an instance of any of the
658 things contained in the second argument tuple. E.g.
659
660 isinstance(x, (A, B))
661
662 returns true if x is an instance of A or B.
663
Guido van Rossum9074ef62001-10-16 21:34:49 +0000664Extension modules
665
666- thread.start_new_thread() now returns the thread ID (previously None).
667
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000668- binascii has now two quopri support functions, a2b_qp and b2a_qp.
669
Guido van Rossumc524d952001-10-19 01:31:59 +0000670- readline now supports setting the startup_hook and the
671 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000672
Guido van Rossumc524d952001-10-19 01:31:59 +0000673- os and posix supports chroot(), setgroups() and unsetenv() where
674 available. The stat(), fstat(), statvfs() and fstatvfs() functions
675 now return "pseudo-sequences" -- the various fields can now be
676 accessed as attributes (e.g. os.stat("/").st_mtime) but for
677 backwards compatibility they also behave as a fixed-length sequence.
678 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000679 attributes.
680
681- time: localtime(), gmtime() and strptime() now return a
682 pseudo-sequence similar to the os.stat() return value, with
683 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000684
Guido van Rossum9074ef62001-10-16 21:34:49 +0000685- Decompression objects in the zlib module now accept an optional
686 second parameter to decompress() that specifies the maximum amount
687 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000688
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000689- optional SSL support in the socket module now exports OpenSSL
690 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
691 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000692 automatically seed its PRNG. Also, the keyfile and certfile
693 arguments to socket.ssl() are now optional.
694
695- posixmodule (and by extension, the os module on POSIX platforms) now
696 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000697
Guido van Rossum9074ef62001-10-16 21:34:49 +0000698Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000699
Tim Peters7402f792001-10-02 03:53:41 +0000700- doctest now excludes functions and classes not defined by the module
701 being tested, thanks to Tim Hochberg.
702
Fred Drakecb7a6b52001-10-22 18:41:51 +0000703- HotShot, a new profiler implemented using a C-based callback, has
704 been added. This substantially reduces the overhead of profiling,
705 but it is still quite preliminary. Support modules and
706 documentation will be added in upcoming releases (before 2.2 final).
707
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000708- profile now produces correct output in situations where an exception
709 raised in Python is cleared by C code (e.g. hasattr()). This used
710 to cause wrong output, including spurious claims of recursive
711 functions and attribution of time spent to the wrong function.
712
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000713 The code and documentation for the derived OldProfile and HotProfile
714 profiling classes was removed. The code hasn't worked for years (if
715 you tried to use them, they raised exceptions). OldProfile
716 intended to reproduce the behavior of the profiler Python used more
717 than 7 years ago, and isn't interesting anymore. HotProfile intended
718 to provide a faster profiler (but producing less information), and
719 that's a worthy goal we intend to meet via a different approach (but
720 without losing information).
721
Tim Peterscce092d2001-10-09 05:31:56 +0000722- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000723 a much better system-specific calibration constant. The constant can
724 now be specified in an instance constructor, or as a Profile class or
725 instance variable, instead of by editing profile.py's source code.
726 Calibration must still be done manually (see the docs for the profile
727 module).
728
729 Note that Profile.calibrate() must be overriden by subclasses.
730 Improving the accuracy required exploiting detailed knowledge of
731 profiler internals; the earlier method abstracted away the details
732 and measured a simplified model instead, but consequently computed
733 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000734
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000735- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000736 which indicates whether output is intended for the header 'Q'
737 encoding.
738
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000739- The SocketServer.ThreadingMixIn class now closes the request after
740 finish_request() returns. (Not when it errors out though.)
741
Barry Warsawf6fb1712001-10-19 05:35:40 +0000742- The nntplib module's NNTP.body() method has grown a `file' argument
743 to allow saving the message body to a file.
744
745- The email package has added a class email.Parser.HeaderParser which
746 only parses headers and does not recurse into the message's body.
747 Also, the module/class MIMEAudio has been added for representing
748 audio data (contributed by Anthony Baxter).
749
750- ftplib should be able to handle files > 2GB.
751
752- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
753 ON, and OFF.
754
Fred Drakecb7a6b52001-10-22 18:41:51 +0000755- xml.dom.minidom NodeList objects now support the length attribute
756 and item() method as required by the DOM specifications.
757
Guido van Rossumed554f62001-10-02 23:15:37 +0000758Tools/Demos
759
760- Demo/dns was removed. It no longer serves any purpose; a package
761 derived from it is now maintained by Anthony Baxter, see
762 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000763
Barry Warsawf6fb1712001-10-19 05:35:40 +0000764- The freeze tool has been made more robust, and two new options have
765 been added: -X and -E.
766
Tim Petersabf925f2001-09-28 21:53:42 +0000767Build
768
Barry Warsawf6fb1712001-10-19 05:35:40 +0000769- configure will use CXX in LINKCC if CXX is used to build main() and
770 the system requires to link a C++ main using the C++ compiler.
771
Tim Petersabf925f2001-09-28 21:53:42 +0000772C API
773
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000774- The documentation for the tp_compare slot is updated to require that
775 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
776 not correct. This is not yet enforced but will be enforced in
777 Python 2.3; even later, we may use -2 to indicate errors and +2 for
778 "NotImplemented". Right now, -1 should be used for an error return.
779
Tim Petersd38b1c72001-09-30 05:09:37 +0000780- PyLong_AsLongLong() now accepts int (as well as long) arguments.
781 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
782 as long) arguments.
783
Guido van Rossum3c288632001-10-16 21:13:49 +0000784- PyThread_start_new_thread() now returns a long int giving the thread
785 ID, if one can be calculated; it returns -1 for error, 0 if no
786 thread ID is calculated (this is an incompatible change, but only
787 the thread module used this API). This code has only really been
788 tested on Linux and Windows; other platforms please beware (and
789 report any bugs or strange behavior).
790
Guido van Rossum1c486092001-10-19 02:05:35 +0000791- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
792 input.
793
Tim Petersabf925f2001-09-28 21:53:42 +0000794New platforms
795
796Tests
797
798Windows
799
Tim Peters04cf1d32001-10-09 22:39:40 +0000800- Installer: If you install IDLE, and don't disable file-extension
801 registration, a new "Edit with IDLE" context (right-click) menu entry
802 is created for .py and .pyw files.
803
Tim Peters1ce3cf72001-10-01 17:58:40 +0000804- The signal module now supports SIGBREAK on Windows, thanks to Steven
805 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
806 action remains to call Win32 ExitProcess(). This can be changed via
807 signal.signal(). For example:
808
809 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
810 # (SIGINT) behavior.
811 import signal
812 signal.signal(signal.SIGBREAK,
813 signal.default_int_handler)
814
815 try:
816 while 1:
817 pass
818 except KeyboardInterrupt:
819 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
820 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
821 # program without the possibility for any Python-level cleanup).
822 print "Clean exit"
823
Tim Petersabf925f2001-09-28 21:53:42 +0000824
Tim Petersb07352e2001-09-08 01:25:47 +0000825What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000826Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000827===========================
828
Guido van Rossum808eea72001-09-25 04:15:41 +0000829Type/class unification and new-style classes
830
831- pydoc and inspect are now aware of new-style classes;
832 e.g. help(list) at the interactive prompt now shows proper
833 documentation for all operations on list objects.
834
835- Applications using Jim Fulton's ExtensionClass module can now safely
836 be used with Python 2.2. In particular, Zope 2.4.1 now works with
837 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
838 examples also work again. It is hoped that Gtk and Boost also work
839 with 2.2a4 and beyond. (If you can confirm this, please write
840 webmaster@python.org; if there are still problems, please open a bug
841 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000842
Tim Peters66c1a522001-09-24 21:17:50 +0000843- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
844 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
845 in the constructed property object. fget, fset and fdel weren't
846 discoverable from Python in 2.2a3. __doc__ is new, and allows to
847 associate a docstring with a property.
848
Guido van Rossum808eea72001-09-25 04:15:41 +0000849- Comparison overloading is now more completely implemented. For
850 example, a str subclass instance can properly be compared to a str
851 instance, and it can properly overload comparison. Ditto for most
852 other built-in object types.
853
854- The repr() of new-style classes has changed; instead of <type
855 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
856 *except* for built-in types, which are still rendered as <type
857 'Foo'> (to avoid upsetting existing code that might parse or
858 otherwise rely on repr() of certain type objects).
859
860- The repr() of new-style objects is now always <Foo object at XXX>;
861 previously, it was sometimes <Foo instance at XXX>.
862
863- For new-style classes, what was previously called __getattr__ is now
864 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000865 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000866 one in classic classes is defined which is called only if regular
867 attribute access raises AttributeError; to catch *all* attribute
868 access, you can use __getattribute__ (for new-style classes). If
869 both are defined, __getattribute__ is called first, and if it raises
870 AttributeError, __getattr__ is called.
871
872- The __class__ attribute of new-style objects can be assigned to.
873 The new class must have the same C-level object layout as the old
874 class.
875
876- The builtin file type can be subclassed now. In the usual pattern,
877 "file" is the name of the builtin type, and file() is a new builtin
878 constructor, with the same signature as the builtin open() function.
879 file() is now the preferred way to open a file.
880
881- Previously, __new__ would only see sequential arguments passed to
882 the type in a constructor call; __init__ would see both sequential
883 and keyword arguments. This made no sense whatsoever any more, so
884 now both __new__ and __init__ see all arguments.
885
886- Previously, hash() applied to an instance of a subclass of str or
887 unicode always returned 0. This has been repaired.
888
889- Previously, an operation on an instance of a subclass of an
890 immutable type (int, long, float, complex, tuple, str, unicode),
891 where the subtype didn't override the operation (and so the
892 operation was handled by the builtin type), could return that
893 instance instead a value of the base type. For example, if s was of
894 a str sublass type, s[:] returned s as-is. Now it returns a str
895 with the same value as s.
896
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000897- Provisional support for pickling new-style objects has been added.
898
Guido van Rossum808eea72001-09-25 04:15:41 +0000899Core
900
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000901- file.writelines() now accepts any iterable object producing strings.
902
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000903- PyUnicode_FromEncodedObject() now works very much like
904 PyObject_Str(obj) in that it tries to use __str__/tp_str
905 on the object if the object is not a string or buffer. This
906 makes unicode() behave like str() when applied to non-string/buffer
907 objects.
908
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000909- PyFile_WriteObject now passes Unicode objects to the file's write
910 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000911 of a print statement must support Unicode objects, i.e. they must
912 at least convert them into ASCII strings.
913
Guido van Rossum624c8af2001-09-18 15:21:04 +0000914- Thread scheduling on Solaris should be improved; it is no longer
915 necessary to insert a small sleep at the start of a thread in order
916 to let other runnable threads be scheduled.
917
Tim Petersb07352e2001-09-08 01:25:47 +0000918Library
919
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000920- StringIO.StringIO instances and cStringIO.StringIO instances support
921 read character buffer compatible objects for their .write() methods.
922 These objects are converted to strings and then handled as such
923 by the instances.
924
Barry Warsaw2f600732001-09-24 04:28:10 +0000925- The "email" package has been added. This is basically a port of the
926 mimelib package <http://sf.net/projects/mimelib> with API changes
927 and some implementations updated to use iterators and generators.
928
Tim Peters8a9c2842001-09-22 21:30:22 +0000929- difflib.ndiff() and difflib.Differ.compare() are generators now. This
930 restores the ability of Tools/scripts/ndiff.py to start producing output
931 before the entire comparison is complete.
932
Barry Warsaw58b072d2001-09-22 04:44:21 +0000933- StringIO.StringIO instances and cStringIO.StringIO instances support
934 iteration just like file objects (i.e. their .readline() method is
935 called for each iteration until it returns an empty string).
936
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000937- The codecs module has grown four new helper APIs to access
938 builtin codecs: getencoder(), getdecoder(), getreader(),
939 getwriter().
940
Guido van Rossum624c8af2001-09-18 15:21:04 +0000941- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
942 simplifies writing XML RPC servers.
943
Barry Warsaw647d5e82001-09-28 17:01:02 +0000944- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000945 after interpretation of symbolic links. On non-Unix systems, this
946 is an alias for os.path.abspath().
947
Tim Peters16a77ad2001-09-08 04:00:12 +0000948- operator.indexOf() (PySequence_Index() in the C API) now works with any
949 iterable object.
950
Guido van Rossum624c8af2001-09-18 15:21:04 +0000951- smtplib now supports various authentication and security features of
952 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000953
Guido van Rossum624c8af2001-09-18 15:21:04 +0000954- hmac: a new module implementing keyed hashing for message
955 authentication.
956
957- mimetypes now recognizes more extensions and file types. At the
958 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000959
Guido van Rossum624c8af2001-09-18 15:21:04 +0000960- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000961 Python 2.2 bytecode generation. It has also been promoted from a
962 Tool to a standard library package. (Tools/compiler still exists as
963 a sample driver.)
964
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000965Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000966
Tim Petersb07352e2001-09-08 01:25:47 +0000967Build
968
Guido van Rossum624c8af2001-09-18 15:21:04 +0000969- Large file support (LFS) is now automatic when the platform supports
970 it; no more manual configuration tweaks are needed. On Linux, at
971 least, it's possible to have a system whose C library supports large
972 files but whose kernel doesn't; in this case, large file support is
973 still enabled but doesn't do you any good unless you upgrade your
974 kernel or share your Python executable with another system whose
975 kernel has large file support.
976
977- The configure script now supplies plausible defaults in a
978 cross-compilation environment. This doesn't mean that the supplied
979 values are always correct, or that cross-compilation now works
980 flawlessly -- but it's a first step (and it shuts up most of
981 autoconf's warnings about AC_TRY_RUN).
982
983- The Unix build is now a bit less chatty, courtesy of the parser
984 generator. The build is completely silent (except for errors) when
985 using "make -s", thanks to a -q option to setup.py.
986
Tim Petersb07352e2001-09-08 01:25:47 +0000987C API
988
Guido van Rossum624c8af2001-09-18 15:21:04 +0000989- The "structmember" API now supports some new flag bits to deny read
990 and/or write access to attributes in restricted execution mode.
991
Tim Petersb07352e2001-09-08 01:25:47 +0000992New platforms
993
Guido van Rossum624c8af2001-09-18 15:21:04 +0000994- Compaq's iPAQ handheld, running the "familiar" Linux distribution
995 (http://familiar.handhelds.org).
996
Tim Petersb07352e2001-09-08 01:25:47 +0000997Tests
998
Tim Peters8a9c2842001-09-22 21:30:22 +0000999- The "classic" standard tests, which work by comparing stdout to
1000 an expected-output file under Lib/test/output/, no longer stop at
1001 the first mismatch. Instead the test is run to completion, and a
1002 variant of ndiff-style comparison is used to report all differences.
1003 This is much easier to understand than the previous style of reporting.
1004
1005- The unittest-based standard tests now use regrtest's test_main()
1006 convention, instead of running as a side-effect of merely being
1007 imported. This allows these tests to be run in more natural and
1008 flexible ways as unittests, outside the regrtest framework.
1009
1010- regrtest.py is much better integrated with unittest and doctest now,
1011 especially in regard to reporting errors.
1012
Tim Petersb07352e2001-09-08 01:25:47 +00001013Windows
1014
Guido van Rossum624c8af2001-09-18 15:21:04 +00001015- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001016 that support it (NTFS under Windows 2000). See "What's New in
1017 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001018
Tim Petersb07352e2001-09-08 01:25:47 +00001019
Tim Petersedc99312001-08-22 21:36:50 +00001020What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001021Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001022===========================
1023
1024Core
1025
Tim Peters9fffa3e2001-09-04 05:14:19 +00001026- Conversion of long to float now raises OverflowError if the long is too
1027 big to represent as a C double.
1028
Tim Peters32f453e2001-09-03 08:35:41 +00001029- The 3-argument builtin pow() no longer allows a third non-None argument
1030 if either of the first two arguments is a float, or if both are of
1031 integer types and the second argument is negative (in which latter case
1032 the arguments are converted to float, so this is really the same
1033 restriction).
1034
Tim Peters5d2b77c2001-09-03 05:47:38 +00001035- The builtin dir() now returns more information, and sometimes much
1036 more, generally naming all attributes of an object, and all attributes
1037 reachable from the object via its class, and from its class's base
1038 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1039 an empty list. In 2.2a3,
1040
1041 >>> dir([])
1042 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1043 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1044 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1045 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1046 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1047 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1048 'reverse', 'sort']
1049
1050 dir(module) continues to return only the module's attributes, though.
1051
Tim Petersbdee63f2001-09-02 03:40:59 +00001052- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001053 than raising OverflowError. This is a partial implementation of PEP
1054 237. You can use -Wdefault::OverflowWarning to enable a warning for
1055 this situation, and -Werror::OverflowWarning to revert to the old
1056 OverflowError exception.
1057
Guido van Rossum61c345f2001-09-04 03:26:15 +00001058- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001059 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001060 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1061 -Qold, meaning the / operator has its classic meaning and no
1062 warnings are issued. Using -Qwarn issues a run-time warning about
1063 all uses of classic division for int and long arguments; -Qwarnall
1064 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001065 (for use with fixdiv.py).
1066 [Note: the remainder of this paragraph (preserved below) became
1067 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1068 <obsolete>
1069 Using -Qnew is questionable; it turns on new division by default, but
1070 only in the __main__ module. You can usefully combine -Qwarn or
1071 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1072 warns about classic division everywhere else.
1073 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001074
Tim Petersbdee63f2001-09-02 03:40:59 +00001075- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001076 long, float, str, unicode, and tuple. (The types complex, list and
1077 dictionary can also be subclassed; this was introduced earlier.)
1078 Note that restrictions apply when subclassing immutable built-in
1079 types: you can only affect the value of the instance by overloading
1080 __new__. You can add mutable attributes, and the subclass instances
1081 will have a __dict__ attribute, but you cannot change the "value"
1082 (as implemented by the base class) of an immutable subclass instance
1083 once it is created.
1084
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001085- The dictionary constructor now takes an optional argument, a
1086 mapping-like object, and initializes the dictionary from its
1087 (key, value) pairs.
1088
Tim Petersbdee63f2001-09-02 03:40:59 +00001089- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001090 "cooperative super calls" in a multiple inheritance setting. For an
1091 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1092
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001093- A new built-in type, property, has been added. This enables the
1094 creation of "properties". These are attributes implemented by
1095 getter and setter functions (or only one of these for read-only or
1096 write-only attributes), without the need to override __getattr__.
1097 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001098
Tim Petersbdee63f2001-09-02 03:40:59 +00001099- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001100 liberalized, to allow leading zeroes. Examples of literals now
1101 legal that were SyntaxErrors before:
1102
1103 00.0 0e3 0100j 07.5 00000000000000000008.
1104
Tim Petersbdee63f2001-09-02 03:40:59 +00001105- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001106 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1107
Tim Petersedc99312001-08-22 21:36:50 +00001108Library
1109
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001110- telnetlib includes symbolic names for the options, and support for
1111 setting an option negotiation callback.
1112
Tim Petersa40c7932001-09-05 22:36:56 +00001113- The new C standard no longer requires that math libraries set errno to
1114 ERANGE on overflow. For platform libraries that exploit this new
1115 freedom, Python's overflow-checking was wholly broken. A new overflow-
1116 checking scheme attempts to repair that, but may not be reliable on all
1117 platforms (C doesn't seem to provide anything both useful and portable
1118 in this area anymore).
1119
Martin v. Löwis44f86962001-09-05 13:44:54 +00001120- Asynchronous timeout actions are available through the new class
1121 threading.Timer.
1122
Tim Peters78526162001-09-05 00:53:45 +00001123- math.log and math.log10 now return sensible results for even huge
1124 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1125
Tim Petersbdee63f2001-09-02 03:40:59 +00001126- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001127 currently held. See the docs for the imp module.
1128
Tim Petersbdee63f2001-09-02 03:40:59 +00001129- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001130 dumps containing ints written on platforms where Python ints are 8 bytes.
1131 When read on a box where Python ints are 4 bytes, such values are
1132 converted to Python longs.
1133
Tim Petersbdee63f2001-09-02 03:40:59 +00001134- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001135 code objects is no longer allowed. This plugs a security hole.
1136
Steve Purcell6091cd62001-09-06 16:05:17 +00001137- unittest.TestResult instances no longer store references to tracebacks
1138 generated by test failures. This prevents unexpected dangling references
1139 to objects that should be garbage collected between tests.
1140
Tim Petersedc99312001-08-22 21:36:50 +00001141Tools
1142
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001143- Tools/scripts/fixdiv.py has been added which can be used to fix
1144 division operators as per PEP 238.
1145
Tim Petersedc99312001-08-22 21:36:50 +00001146Build
1147
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001148- If you are an adventurous person using Mac OS X you may want to look at
1149 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1150 application, which can be used for experimenting with Carbon or Cocoa.
1151 Discussion of this on pythonmac-sig, please.
1152
Tim Peters7eea37e2001-09-04 22:08:56 +00001153C API
1154
1155- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001156
Tim Peters9fffa3e2001-09-04 05:14:19 +00001157- Note that PyLong_AsDouble can fail! This has always been true, but no
1158 callers checked for it. It's more likely to fail now, because overflow
1159 errors are properly detected now. The proper way to check:
1160
1161 double x = PyLong_AsDouble(some_long_object);
1162 if (x == -1.0 && PyErr_Occurred()) {
1163 /* The conversion failed. */
1164 }
1165
Tim Petersbdee63f2001-09-02 03:40:59 +00001166- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001167 compile but will not participate in GC. To upgrade an extension
1168 module:
1169
1170 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001171
Neil Schemenauer4042c692001-08-30 15:38:01 +00001172 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1173 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001174
Neil Schemenauer4042c692001-08-30 15:38:01 +00001175 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1176 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001177
Neil Schemenauer4042c692001-08-30 15:38:01 +00001178 - remove PyGC_HEAD_SIZE from object size calculations
1179
1180 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1181
Tim Petersbdee63f2001-09-02 03:40:59 +00001182- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001183 These can be used safely to construct string objects from a
1184 sprintf-style format string (similar to the format string supported
1185 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001186
Tim Petersedc99312001-08-22 21:36:50 +00001187New platforms
1188
Tim Petersb7da0902001-09-02 23:01:43 +00001189- Stephen Hansen contributed patches sufficient to get a clean compile
1190 under Borland C (Windows), but he reports problems running it and ran
1191 out of time to complete the port. Volunteers? Expect a MemoryError
1192 when importing the types module; this is probably shallow, and
1193 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001194
Tim Petersedc99312001-08-22 21:36:50 +00001195Tests
1196
1197Windows
1198
Tim Peters6e13a562001-09-06 00:32:15 +00001199- Large file support is now enabled on Win32 platforms as well as on
1200 Win64. This means that, for example, you can use f.tell() and f.seek()
1201 to manipulate files larger than 2 gigabytes (provided you have enough
1202 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001203 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1204 filesize limit, and large file support makes no difference there.
1205 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1206 NTFS has no practical limit on file size, and files of any size can be
1207 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001208
Tim Petersbdee63f2001-09-02 03:40:59 +00001209- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001210 points to command.com (patch from Brian Quinlan).
1211
Tim Petersedc99312001-08-22 21:36:50 +00001212
Tim Peters20f51a72001-07-21 02:31:40 +00001213What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001214Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001215===========================
1216
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001217Build
1218
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001219- Tim Peters developed a brand new Windows installer using Wise 8.1,
1220 generously donated to us by Wise Solutions.
1221
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001222- configure supports a new option --enable-unicode, with the values
1223 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1224 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001225
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001226- A new configure option --enable-framework builds a Mac OS X framework,
1227 which "make frameworkinstall" will install. This provides a starting
1228 point for more mac-like functionality, join pythonmac-sig@python.org
1229 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001230
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001231- The NeXT platform is no longer supported.
1232
1233- The `new' module is now statically linked.
1234
Tim Peters0afb6092001-08-15 06:06:44 +00001235Tools
1236
1237- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001238 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001239 the module docstring for details.
1240
Tim Peters20f51a72001-07-21 02:31:40 +00001241Tests
1242
Tim Peters5e824c32001-08-12 22:25:01 +00001243- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001244 platforms, allowing to give clearer test result output. regrtest
1245 also has optional --use/-u switch to run normally disabled tests
1246 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001247
Tim Peters20f51a72001-07-21 02:31:40 +00001248- Several new tests in the standard test suite, with special thanks to
1249 Nick Mathewson.
1250
1251Core
1252
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001253- The floor division operator // has been added as outlined in PEP
1254 238. The / operator still provides classic division (and will until
1255 Python 3.0) unless "from __future__ import division" is included, in
1256 which case the / operator will provide true division. The operator
1257 module provides truediv() and floordiv() functions. Augmented
1258 assignment variants are included, as are the equivalent overloadable
1259 methods and C API methods. See the PEP for a full discussion:
1260 <http://python.sf.net/peps/pep-0238.html>
1261
Tim Peters6cd6a822001-08-17 22:11:27 +00001262- Future statements are now effective in simulated interactive shells
1263 (like IDLE). This should "just work" by magic, but read Michael
1264 Hudson's "Future statements in simulated shells" PEP 264 for full
1265 details: <http://python.sf.net/peps/pep-0264.html>.
1266
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001267- The type/class unification (PEP 252-253) was integrated into the
1268 trunk and is not so tentative any more (the exact specification of
1269 some features is still tentative). A lot of work has done on fixing
1270 bugs and adding robustness and features (performance still has to
1271 come a long way).
1272
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001273- Warnings about a mismatch in the Python API during extension import
1274 now use the Python warning framework (which makes it possible to
1275 write filters for these warnings).
1276
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001277- A function's __dict__ (aka func_dict) will now always be a
1278 dictionary. It used to be possible to delete it or set it to None,
1279 but now both actions raise TypeErrors. It is still legal to set it
1280 to a dictionary object. Getting func.__dict__ before any attributes
1281 have been assigned now returns an empty dictionary instead of None.
1282
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001283- A new command line option, -E, was added which disables the use of
1284 all environment variables, or at least those that are specifically
1285 significant to Python. Usually those have a name starting with
1286 "PYTHON". This was used to fix a problem where the tests fail if
1287 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1288 older distribution.
1289
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001290Library
1291
Tim Peters5e824c32001-08-12 22:25:01 +00001292- New class Differ and new functions ndiff() and restore() in difflib.py.
1293 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001294 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001295
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001296- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1297 value using the minimal quoting required for the value; more
1298 reliable than using xml.sax.saxutils.escape() for attribute values.
1299
1300- Readline completion support for cmd.Cmd was added.
1301
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001302- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1303
1304- Added function threading.BoundedSemaphore()
1305
1306- Added Ka-Ping Yee's cgitb.py module.
1307
1308- The `new' module now exposes the CO_xxx flags.
1309
Martin v. Löwis560da622001-11-24 09:24:51 +00001310- The gc module offers the get_referents function.
1311
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001312New platforms
1313
1314C API
1315
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001316- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1317 which provide a cross-platform implementations for the
1318 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1319 the standard sprintf() and vsprintf() C lib APIs, these versions
1320 apply bounds checking on the used buffer which enhances protection
1321 against buffer overruns.
1322
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001323- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001324 and extensions using different Unicode widths is rendered next to
1325 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001326 will result in an ImportError. Unicode extensions writers must make
1327 sure to check the Unicode width compatibility in their extensions by
1328 using at least one of the mangled Unicode APIs in the extension.
1329
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001330- Two new flags METH_NOARGS and METH_O are available in method definition
1331 tables to simplify implementation of methods with no arguments and a
1332 single untyped argument. Calling such methods is more efficient than
1333 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1334 deprecated.
1335
Tim Petersc1731372001-08-04 08:12:36 +00001336Windows
1337
1338- "import module" now compiles module.pyw if it exists and nothing else
1339 relevant is found.
1340
Tim Peters20f51a72001-07-21 02:31:40 +00001341
Guido van Rossum55a78992001-07-17 17:22:32 +00001342What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001343Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001344===========================
1345
1346Core
Tim Petersa814db52001-05-14 07:05:58 +00001347
Tim Peters6d6c1a32001-08-02 04:15:00 +00001348- TENTATIVELY, a large amount of code implementing much of what's
1349 described in PEP 252 (Making Types Look More Like Classes) and PEP
1350 253 (Subtyping Built-in Types) was added. This will be released
1351 with Python 2.2a1. Documentation will be provided separately
1352 through http://www.python.org/2.2/. The purpose of releasing this
1353 with Python 2.2a1 is to test backwards compatibility. It is
1354 possible, though not likely, that a decision is made not to release
1355 this code as part of 2.2 final, if any serious backwards
1356 incompapatibilities are found during alpha testing that cannot be
1357 repaired.
1358
Guido van Rossum55a78992001-07-17 17:22:32 +00001359- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001360 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001361 more 'yield' statements. See PEP 255. Since this adds a new
1362 keyword to the language, this feature must be enabled by including a
1363 future statement: "from __future__ import generators" (see PEP 236).
1364 Generators will become a standard feature in a future release
1365 (probably 2.3). Without this future statement, 'yield' remains an
1366 ordinary identifier, but a warning is issued each time it is used.
1367 (These warnings currently don't conform to the warnings framework of
1368 PEP 230; we intend to fix this in 2.2a2.)
1369
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001370- The UTF-16 codec was modified to be more RFC compliant. It will now
1371 only remove BOM characters at the start of the string and then
1372 only if running in native mode (UTF-16-LE and -BE won't remove a
1373 leading BMO character).
1374
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001375- Strings now have a new method .decode() to complement the already
1376 existing .encode() method. These two methods provide direct access
1377 to the corresponding decoders and encoders of the registered codecs.
1378
1379 To enhance the usability of the .encode() method, the special
1380 casing of Unicode object return values was dropped (Unicode objects
1381 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001382
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001383 Both methods will now return whatever the codec in charge of the
1384 requested encoding returns as object, e.g. Unicode codecs will
1385 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1386 will return u"äöü"). This enables codec writer to create codecs
1387 for various simple to use conversions.
1388
1389 New codecs were added to demonstrate these new features (the .encode()
1390 and .decode() columns indicate the type of the returned objects):
1391
1392 Name | .encode() | .decode() | Description
1393 ----------------------------------------------------------------------
1394 uu | string | string | UU codec (e.g. for email)
1395 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001396 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001397 zlib | string | string | zlib compression
1398 hex | string | string | 2-byte hex codec
1399 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1400
Mark Hammond2a0af792001-05-14 03:09:36 +00001401- Some operating systems now support the concept of a default Unicode
1402 encoding for file system operations. Notably, Windows supports 'mbcs'
1403 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001404 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001405 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001406
1407 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001408 functions that return filenames (such as os.listdir()) to return Python
1409 string objects pre-encoded using the default file system encoding for
1410 the platform. As this encoding is likely to be different from Python's
1411 default encoding, converting this name to a Unicode object before passing
1412 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001413 would attempt to use its default encoding (generally ASCII) rather than
1414 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001415
Tim Petersa814db52001-05-14 07:05:58 +00001416 In general, this change simply removes surprises when working with
1417 Unicode and the file system, making these operations work as you expect,
1418 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001419 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001420
Tim Peters61dff2b2001-05-08 15:43:37 +00001421- Float (and complex) literals in source code were evaluated to full
1422 precision only when running from a .py file; the same code loaded from a
1423 .pyc (or .pyo) file could suffer numeric differences starting at about the
1424 12th significant decimal digit. For example, on a machine with IEEE-754
1425 floating arithmetic,
1426
1427 x = 9007199254740992.0
1428 print long(x)
1429
1430 printed 9007199254740992 if run directly from .py, but 9007199254740000
1431 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1432 str(float) instead of repr(float) when building code objects. marshal
1433 now uses repr(float) instead, which should reproduce floats to full
1434 machine precision (assuming the platform C float<->string I/O conversion
1435 functions are of good quality).
1436
1437 This may cause floating-point results to change in some cases, and
1438 usually for the better, but may also cause numerically unstable
1439 algorithms to break.
1440
Tim Peters2f228e72001-05-13 00:19:31 +00001441- The implementation of dicts suffers fewer collisions, which has speed
1442 benefits. However, the order in which dict entries appear in dict.keys(),
1443 dict.values() and dict.items() may differ from previous releases for a
1444 given dict. Nothing is defined about this order, so no program should
1445 rely on it. Nevertheless, it's easy to write test cases that rely on the
1446 order by accident, typically because of printing the str() or repr() of a
1447 dict to an "expected results" file. See Lib/test/test_support.py's new
1448 sortdict(dict) function for a simple way to display a dict in sorted
1449 order.
1450
Tim Peters7a3bfc32001-06-12 01:22:22 +00001451- Many other small changes to dicts were made, resulting in faster
1452 operation along the most common code paths.
1453
Guido van Rossum10315822001-05-01 20:54:30 +00001454- Dictionary objects now support the "in" operator: "x in dict" means
1455 the same as dict.has_key(x).
1456
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001457- The update() method of dictionaries now accepts generic mapping
1458 objects. Specifically the argument object must support the .keys()
1459 and __getitem__() methods. This allows you to say, for example,
1460 {}.update(UserDict())
1461
Guido van Rossum10315822001-05-01 20:54:30 +00001462- Iterators were added; this is a generalized way of providing values
1463 to a for loop. See PEP 234. There's a new built-in function iter()
1464 to return an iterator. There's a new protocol to get the next value
1465 from an iterator using the next() method (in Python) or the
1466 tp_iternext slot (in C). There's a new protocol to get iterators
1467 using the __iter__() method (in Python) or the tp_iter slot (in C).
1468 Iterating (i.e. a for loop) over a dictionary generates its keys.
1469 Iterating over a file generates its lines.
1470
Tim Petersf553f892001-05-01 20:45:31 +00001471- The following functions were generalized to work nicely with iterator
1472 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001473 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001474 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1475 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001476 join() method of strings
1477 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001478 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1479 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001480 right-hand side of assignment statements with multiple targets, such as
1481 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001482
Tim Petersd85e1022001-05-11 21:51:48 +00001483- Accessing module attributes is significantly faster (for example,
1484 random.random or os.path or yourPythonModule.yourAttribute).
1485
Tim Peterse63415e2001-05-08 04:38:29 +00001486- Comparing dictionary objects via == and != is faster, and now works even
1487 if the keys and values don't support comparisons other than ==.
1488
Tim Peters95bf9392001-05-10 08:32:44 +00001489- Comparing dictionaries in ways other than == and != is slower: there were
1490 insecurities in the dict comparison implementation that could cause Python
1491 to crash if the element comparison routines for the dict keys and/or
1492 values mutated the dicts. Making the code bulletproof slowed it down.
1493
Tim Peterseb28ef22001-06-02 05:27:19 +00001494- Collisions in dicts are resolved via a new approach, which can help
1495 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001496 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001497 faster now. Thanks to Christian Tismer for pointing out the cause and
1498 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001499
Tim Peters52e155e2001-06-16 05:42:57 +00001500- repr() is much faster for large containers (dict, list, tuple).
1501
1502
Tim Petersa814db52001-05-14 07:05:58 +00001503Library
1504
Fred Drake960fdf92001-07-20 18:38:26 +00001505- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1506 were added to the string module. These a locale-indenpendent
1507 constants, unlike letters, lowercase, and uppercase. These are now
1508 use in appropriate locations in the standard library.
1509
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001510- The flags used in dlopen calls can now be configured using
1511 sys.setdlopenflags and queried using sys.getdlopenflags.
1512
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001513- Fredrik Lundh's xmlrpclib is now a standard library module. This
1514 provides full client-side XML-RPC support. In addition,
1515 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1516 one asyncore-based). Thanks to Eric Raymond for the documentation.
1517
Guido van Rossum643d3912001-07-05 14:46:25 +00001518- The xrange() object is simplified: it no longer supports slicing,
1519 repetition, comparisons, efficient 'in' checking, the tolist()
1520 method, or the start, stop and step attributes. See PEP 260.
1521
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001522- A new function fnmatch.filter to filter lists of file names was added.
1523
Barry Warsawffd674d2001-05-22 16:00:10 +00001524- calendar.py uses month and day names based on the current locale.
1525
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001526- strop is now *really* obsolete (this was announced before with 1.6),
1527 and issues DeprecationWarning when used (except for the four items
1528 that are still imported into string.py).
1529
Tim Petersa814db52001-05-14 07:05:58 +00001530- Cookie.py now sorts key+value pairs by key in output strings.
1531
1532- pprint.isrecursive(object) didn't correctly identify recursive objects.
1533 Now it does.
1534
Tim Peters95b3f782001-05-14 18:39:41 +00001535- pprint functions now much faster for large containers (tuple, list, dict).
1536
Tim Peters7b9542a2001-06-10 23:40:19 +00001537- New 'q' and 'Q' format codes in the struct module, corresponding to C
1538 types "long long" and "unsigned long long" (on Windows, __int64). In
1539 native mode, these can be used only when the platform C compiler supports
1540 these types (when HAVE_LONG_LONG is #define'd by the Python config
1541 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001542 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1543 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001544
Guido van Rossum83213cc2001-06-12 16:48:52 +00001545- The site module installs a new built-in function 'help' that invokes
1546 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1547 it displays a message reminding the user to use 'help()' or
1548 'help(object)'.
1549
Tim Petersa814db52001-05-14 07:05:58 +00001550Tests
1551
1552- New test_mutants.py runs dict comparisons where the key and value
1553 comparison operators mutute the dicts randomly during comparison. This
1554 rapidly causes Python to crash under earlier releases (not for the faint
1555 of heart: it can also cause Win9x to freeze or reboot!).
1556
1557- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001558 pprint.isreadable() return sensible results. Also verifies that simple
1559 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001560
Tim Peters4324aa32001-05-28 22:30:08 +00001561C API
1562
1563- Removed the unused last_is_sticky argument from the internal
1564 _PyTuple_Resize(). If this affects you, you were cheating.
1565
1566
Guido van Rossum55a78992001-07-17 17:22:32 +00001567======================================================================
1568
1569
Guido van Rossumffe13be2001-04-16 18:46:45 +00001570What's New in Python 2.1 (final)?
1571=================================
1572
1573We only changed a few things since the last release candidate, all in
1574Python library code:
1575
1576- A bug in the locale module was fixed that affected locales which
1577 define no grouping for numeric formatting.
1578
1579- A few bugs in the weakref module's implementations of weak
1580 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1581 and the test suite was updated to check for these bugs.
1582
1583- An old bug in the os.path.walk() function (introduced in Python
1584 2.0!) was fixed: a non-existent file would cause an exception
1585 instead of being ignored.
1586
1587- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1588 PyChecker.
1589
1590
Guido van Rossum5b08f132001-04-16 02:05:23 +00001591What's New in Python 2.1c2?
1592===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001593
Guido van Rossum5b08f132001-04-16 02:05:23 +00001594A flurry of small changes, and one showstopper fixed in the nick of
1595time made it necessary to release another release candidate. The list
1596here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001597
Guido van Rossum5b08f132001-04-16 02:05:23 +00001598Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001599
Guido van Rossum5b08f132001-04-16 02:05:23 +00001600- Tim discovered a nasty bug in the dictionary code, caused by
1601 PyDict_Next() calling dict_resize(), and the GC code's use of
1602 PyDict_Next() violating an assumption in dict_items(). This was
1603 fixed with considerable amounts of band-aid, but the net effect is a
1604 saner and more robust implementation.
1605
1606- Made a bunch of symbols static that were accidentally global.
1607
1608Build and Ports
1609
1610- The setup.py script didn't check for a new enough version of zlib
1611 (1.1.3 is needed). Now it does.
1612
1613- Changed "make clean" target to also remove shared libraries.
1614
1615- Added a more general warning about the SGI Irix optimizer to README.
1616
1617Library
1618
1619- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1620 omitted the slash between host and file.html.
1621
1622- The mailbox module's _Mailbox class contained a completely broken
1623 and undocumented seek() method. Ripped it out.
1624
1625- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1626 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1627
1628- Fixed a few last-minute bugs in unittest.
1629
1630Extensions
1631
1632- Reverted the patch to the OpenSSL code in socketmodule.c to support
1633 RAND_status() and the EGD, and the subsequent patch that tried to
1634 fix it for pre-0.9.5 versions; the problem with the patch is that on
1635 some systems it issues a warning whenever socket is imported, and
1636 that's unacceptable.
1637
1638Tests
1639
1640- Fixed the pickle tests to work with "import test.test_pickle".
1641
1642- Tweaked test_locale.py to actually run the test Windows.
1643
1644- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1645 not "wb" (which is not a valid mode at all).
1646
1647- Fix pstats browser crashes. Import readline if it exists to make
1648 the user interface nicer.
1649
1650- Add "import thread" to the top of test modules that import the
1651 threading module (test_asynchat and test_threadedtempfile). This
1652 prevents test failures caused by a broken threading module resulting
1653 from a previously caught failed import.
1654
1655- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1656 needed on some platforms (e.g. Solaris 8) when the tests are run
1657 twice in succession.
1658
1659- Skip rather than fail test_sunaudiodev if no audio device is found.
1660
1661
1662What's New in Python 2.1c1?
1663===========================
1664
1665This list was significantly updated when 2.1c2 was released; the 2.1c1
1666release didn't mention most changes that were actually part of 2.1c1:
1667
1668Legal
1669
1670- Copyright was assigned to the Python Software Foundation (PSF) and a
1671 PSF license (very similar to the CNRI license) was added.
1672
1673- The CNRI copyright notice was updated to include 2001.
1674
1675Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001676
Guido van Rossumc9932722001-04-12 02:31:27 +00001677- After a public outcry, assignment to __debug__ is no longer illegal;
1678 instead, a warning is issued. It will become illegal in 2.2.
1679
Guido van Rossum5b08f132001-04-16 02:05:23 +00001680- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1681 "%#x" now always prepends "0x", even if the value is zero.
1682
1683- Fixed some nits in the bytecode compiler.
1684
1685- Fixed core dumps when calling certain kinds of non-functions.
1686
1687- Fixed various core dumps caused by reference count bugs.
1688
1689Build and Ports
1690
1691- Use INSTALL_SCRIPT to install script files.
1692
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001693- New port: SCO Unixware 7, by Billy G. Allie.
1694
Guido van Rossum5b08f132001-04-16 02:05:23 +00001695- Updated RISCOS port.
1696
1697- Updated BeOS port and notes.
1698
1699- Various other porting problems resolved.
1700
1701Library
1702
1703- The TERMIOS and SOCKET modules are now truly obsolete and
1704 unnecessary. Their symbols are incorporated in the termios and
1705 socket modules.
1706
1707- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1708 better tests for pickling.
1709
1710- threading: make Condition.wait() robust against KeyboardInterrupt.
1711
1712- zipfile: add support to zipfile to support opening an archive
1713 represented by an open file rather than a file name. Fix bug where
1714 the archive was not properly closed. Fixed a bug in this bugfix
1715 where flush() was called for a read-only file.
1716
1717- imputil: added an uninstall() method to the ImportManager.
1718
1719- Canvas: fixed bugs in lower() and tkraise() methods.
1720
1721- SocketServer: API change (added overridable close_request() method)
1722 so that the TCP server can explicitly close the request.
1723
1724- pstats: Eric Raymond added a simple interactive statistics browser,
1725 invoked when the module is run as a script.
1726
1727- locale: fixed a problem in format().
1728
1729- webbrowser: made it work when the BROWSER environment variable has a
1730 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1731 KDE 2. Fixed some other nits.
1732
1733- unittest: changes to allow using a different exception than
1734 AssertionError, and added a few more function aliases. Some other
1735 small changes.
1736
1737- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1738
1739- asynchat: fixed a critical bug in asynchat that slipped through the
1740 2.1b2 release. Fixed another rare bug.
1741
1742- Fix some unqualified except: clauses (always a bad code example).
1743
1744XML
1745
1746- pyexpat: new API get_version_string().
1747
1748- Fixed some minidom bugs.
1749
1750Extensions
1751
1752- Fixed a core dump in _weakref. Removed the weakref.mapping()
1753 function (it adds nothing to the API).
1754
1755- Rationalized the use of header files in the readline module, to make
1756 it compile (albeit with some warnings) with the very recent readline
1757 4.2, without breaking for earlier versions.
1758
1759- Hopefully fixed a buffering problem in linuxaudiodev.
1760
1761- Attempted a fix to make the OpenSSL support in the socket module
1762 work again with pre-0.9.5 versions of OpenSSL.
1763
1764Tests
1765
1766- Added a test case for asynchat and asyncore.
1767
1768- Removed coupling between tests where one test failing could break
1769 another.
1770
1771Tools
1772
1773- Ping added an interactive help browser to pydoc, fixed some nits
1774 in the rest of the pydoc code, and added some features to his
1775 inspect module.
1776
1777- An updated python-mode.el version 4.1 which integrates Ken
1778 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1779 much nicer in XEmacs and Emacs. When stepping through your program
1780 with pdb, in either the shell window or the *Python* window, the
1781 source file and line will be tracked by an arrow. Very cool!
1782
1783- IDLE: syntax warnings in interactive mode are changed into errors.
1784
1785- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001786 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001787
1788- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001789
Barry Warsaw11e89c72001-04-11 20:37:57 +00001790
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001791What's New in Python 2.1 beta 2?
1792================================
1793
Guido van Rossum053ae352001-03-22 14:17:21 +00001794(Unlisted are many fixed bugs, more documentation, etc.)
1795
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001796Core language, builtins, and interpreter
1797
Guido van Rossum053ae352001-03-22 14:17:21 +00001798- The nested scopes work (enabled by "from __future__ import
1799 nested_scopes") is completed; in particular, the future now extends
1800 into code executed through exec, eval() and execfile(), and into the
1801 interactive interpreter.
1802
1803- When calling a base class method (e.g. BaseClass.__init__(self)),
1804 this is now allowed even if self is not strictly spoken a class
1805 instance (e.g. when using metaclasses or the Don Beaudry hook).
1806
1807- Slice objects are now comparable but not hashable; this prevents
1808 dict[:] from being accepted but meaningless.
1809
1810- Complex division is now calculated using less braindead algorithms.
1811 This doesn't change semantics except it's more likely to give useful
1812 results in extreme cases. Complex repr() now uses full precision
1813 like float repr().
1814
1815- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1816
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001817- It is illegal to assign to the name __debug__, which is set when the
1818 interpreter starts. It is effectively a compile-time constant.
1819
1820- A warning will be issued if a global statement for a variable
1821 follows a use or assignment of that variable.
1822
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001823Standard library
1824
Guido van Rossum053ae352001-03-22 14:17:21 +00001825- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1826 inspired by JUnit), is now part of the standard library. You now
1827 have a choice of two testing frameworks: unittest requires you to
1828 write testcases as separate code, doctest gathers them from
1829 docstrings. Both approaches have their advantages and
1830 disadvantages.
1831
1832- A new module Tix was added, which wraps the Tix extension library
1833 for Tk. With that module, it is not necessary to statically link
1834 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1835 require" command. See Demo/tix/.
1836
1837- tzparse.py is now obsolete.
1838
1839- In gzip.py, the seek() and tell() methods are removed -- they were
1840 non-functional anyway, and it's better if callers can test for their
1841 existence with hasattr().
1842
1843Python/C API
1844
1845- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1846 that's already in the dictionary during a PyDict_Next() iteration.
1847 This used to fail occasionally when a dictionary resize operation
1848 could be triggered that would rehash all the keys. All other
1849 modifications to the dictionary are still off-limits during a
1850 PyDict_Next() iteration!
1851
1852- New extended APIs related to passing compiler variables around.
1853
1854- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1855 implement isinstance() and issubclass().
1856
1857- Py_BuildValue() now has a "D" conversion to create a Python complex
1858 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001859
Fred Drake4e262a92001-03-22 18:26:47 +00001860- Extensions types which support weak references must now set the
1861 field allocated for the weak reference machinery to NULL themselves;
1862 this is done to avoid the cost of checking each object for having a
1863 weakly referencable type in PyObject_INIT(), since most types are
1864 not weakly referencable.
1865
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001866- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1867 free variables and cell variables to and from the frame's f_locals.
1868
1869- Variants of several functions defined in pythonrun.h have been added
1870 to support the nested_scopes future statement. The variants all end
1871 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1872 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1873 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001874 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001875
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001876Distutils
1877
1878- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1879 into the release tree.
1880
Tim Peters0e57abf2001-05-02 07:39:38 +00001881- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001882 (an uninstaller, more customization of the installer's display)
1883
1884- from Jack Jansen: added Mac-specific code to generate a dialog for
1885 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001886 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001887 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001888
1889- added 'platforms' and 'keywords' to the set of metadata that can be
1890 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001891
1892- applied patches from Jason Tishler to make the compiler class work with
1893 Cygwin.
1894
1895
Tim Peters2fe289a2001-03-01 22:19:38 +00001896What's New in Python 2.1 beta 1?
1897================================
Tim Petersd66595f2001-02-04 03:09:53 +00001898
1899Core language, builtins, and interpreter
1900
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001901- Following an outcry from the community about the amount of code
1902 broken by the nested scopes feature introduced in 2.1a2, we decided
1903 to make this feature optional, and to wait until Python 2.2 (or at
1904 least 6 months) to make it standard. The option can be enabled on a
1905 per-module basis by adding "from __future__ import nested_scopes" at
1906 the beginning of a module (before any other statements, but after
1907 comments and an optional docstring). See PEP 236 (Back to the
1908 __future__) for a description of the __future__ statement. PEP 227
1909 (Statically Nested Scopes) has been updated to reflect this change,
1910 and to clarify the semantics in a number of endcases.
1911
1912- The nested scopes code, when enabled, has been hardened, and most
1913 bugs and memory leaks in it have been fixed.
1914
1915- Compile-time warnings are now generated for a number of conditions
1916 that will break or change in meaning when nested scopes are enabled:
1917
1918 - Using "from...import *" or "exec" without in-clause in a function
1919 scope that also defines a lambda or nested function with one or
1920 more free (non-local) variables. The presence of the import* or
1921 bare exec makes it impossible for the compiler to determine the
1922 exact set of local variables in the outer scope, which makes it
1923 impossible to determine the bindings for free variables in the
1924 inner scope. To avoid the warning about import *, change it into
1925 an import of explicitly name object, or move the import* statement
1926 to the global scope; to avoid the warning about bare exec, use
1927 exec...in... (a good idea anyway -- there's a possibility that
1928 bare exec will be deprecated in the future).
1929
1930 - Use of a global variable in a nested scope with the same name as a
1931 local variable in a surrounding scope. This will change in
1932 meaning with nested scopes: the name in the inner scope will
1933 reference the variable in the outer scope rather than the global
1934 of the same name. To avoid the warning, either rename the outer
1935 variable, or use a global statement in the inner function.
1936
Neil Schemenauera35c6882001-02-27 04:45:05 +00001937- An optional object allocator has been included. This allocator is
1938 optimized for Python objects and should be faster and use less memory
1939 than the standard system allocator. It is not enabled by default
1940 because of possible thread safety problems. The allocator is only
1941 protected by the Python interpreter lock and it is possible that some
1942 extension modules require a thread safe allocator. The object
1943 allocator can be enabled by providing the "--with-pymalloc" option to
1944 configure.
1945
Tim Petersd66595f2001-02-04 03:09:53 +00001946Standard library
1947
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001948- pyexpat now detects the expat version if expat.h defines it. A
1949 number of additional handlers are provided, which are only available
1950 since expat 1.95. In addition, the methods SetParamEntityParsing and
1951 GetInputContext of Parser objects are available with 1.95.x
1952 only. Parser objects now provide the ordered_attributes and
1953 specified_attributes attributes. A new module expat.model was added,
1954 which offers a number of additional constants if 1.95.x is used.
1955
1956- xml.dom offers the new functions registerDOMImplementation and
1957 getDOMImplementation.
1958
1959- xml.dom.minidom offers a toprettyxml method. A number of DOM
1960 conformance issues have been resolved. In particular, Element now
1961 has an hasAttributes method, and the handling of namespaces was
1962 improved.
1963
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001964- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1965 getting information about live Python code, and pydoc.py, a module
1966 for interactively converting docstrings to HTML or text.
1967 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001968 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001969 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1970 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001971
Tim Peters1eff7962001-03-01 02:31:33 +00001972- New library module difflib.py, primarily packaging the SequenceMatcher
1973 class at the heart of the popular ndiff.py file-comparison tool.
1974
1975- doctest.py (a framework for verifying Python code examples in docstrings)
1976 is now part of the std library.
1977
Tim Petersd66595f2001-02-04 03:09:53 +00001978Windows changes
1979
Guido van Rossume3955a82001-03-02 14:05:59 +00001980- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1981 small GUI that lets you browse the module docstrings using your
1982 default web browser.
1983
Tim Peters1eff7962001-03-01 02:31:33 +00001984- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1985 Platforms) is implemented. See
1986
1987 http://python.sourceforge.net/peps/pep-0235.html
1988
1989 for full details, especially the "Current Lower-Left Semantics" section.
1990 The new Windows import rules are simpler than before:
1991
1992 A. If the PYTHONCASEOK environment variable exists, same as
1993 before: silently accept the first case-insensitive match of any
1994 kind; raise ImportError if none found.
1995
1996 B. Else search sys.path for the first case-sensitive match; raise
1997 ImportError if none found.
1998
1999 The same rules have been implented on other platforms with case-
2000 insensitive but case-preserving filesystems too (including Cygwin, and
2001 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002002
Tim Peters25a9ce32001-02-19 07:06:36 +00002003- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2004 what it's supposed to do (and does do under NT and 2000) via direct
2005 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002006 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002007 all Win9x systems before.
2008
Tim Peters1eff7962001-03-01 02:31:33 +00002009- Build: Subproject _test (effectively) renamed to _testcapi.
2010
Tim Peters2fe289a2001-03-01 22:19:38 +00002011New platforms
2012
2013- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2014 Thanks to Steven Majewski!
2015
2016- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2017 Tishler!
2018
Guido van Rossum9089b272001-03-02 06:49:50 +00002019- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2020 Schwertberger! See RISCOS/README for more information -- it seems
2021 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002022 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002023
Tim Peters25a9ce32001-02-19 07:06:36 +00002024
Tim Petersd7b5e882001-01-25 03:36:26 +00002025What's New in Python 2.1 alpha 2?
2026=================================
Tim Peters40ead762001-01-27 05:35:26 +00002027
Tim Petersd7b5e882001-01-25 03:36:26 +00002028Core language, builtins, and interpreter
2029
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002030- Scopes nest. If a name is used in a function or class, but is not
2031 local, the definition in the nearest enclosing function scope will
2032 be used. One consequence of this change is that lambda statements
2033 could reference variables in the namespaces where the lambda is
2034 defined. In some unusual cases, this change will break code.
2035
2036 In all previous version of Python, names were resolved in exactly
2037 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002038 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002039 function A is defined within a function B, the names bound in B are
2040 not visible in A. The new rules make names bound in B visible in A,
2041 unless A contains a name binding that hides the binding in B.
2042
2043 Section 4.1 of the reference manual describes the new scoping rules
2044 in detail. The test script in Lib/test/test_scope.py demonstrates
2045 some of the effects of the change.
2046
2047 The new rules will cause existing code to break if it defines nested
2048 functions where an outer function has local variables with the same
2049 name as globals or builtins used by the inner function. Example:
2050
2051 def munge(str):
2052 def helper(x):
2053 return str(x)
2054 if type(str) != type(''):
2055 str = helper(str)
2056 return str.strip()
2057
2058 Under the old rules, the name str in helper() is bound to the
2059 builtin function str(). Under the new rules, it will be bound to
2060 the argument named str and an error will occur when helper() is
2061 called.
2062
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002063- The compiler will report a SyntaxError if "from ... import *" occurs
2064 in a function or class scope. The language reference has documented
2065 that this case is illegal, but the compiler never checked for it.
2066 The recent introduction of nested scope makes the meaning of this
2067 form of name binding ambiguous. In a future release, the compiler
2068 may allow this form when there is no possibility of ambiguity.
2069
Tim Peters40ead762001-01-27 05:35:26 +00002070- repr(string) is easier to read, now using hex escapes instead of octal,
2071 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2072
2073 >>> "\texample \r\n" + chr(0) + chr(255)
2074 '\texample \r\n\x00\xff' # in 2.1
2075 '\011example \015\012\000\377' # in 2.0
2076
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002077- Functions are now compared and hashed by identity, not by value, since
2078 the func_code attribute is writable.
2079
Fred Drakefb9d7122001-02-01 20:00:40 +00002080- Weak references (PEP 205) have been added. This involves a few
2081 changes in the core, an extension module (_weakref), and a Python
2082 module (weakref). The weakref module is the public interface. It
2083 includes support for "explicit" weak references, proxy objects, and
2084 mappings with weakly held values.
2085
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002086- A 'continue' statement can now appear in a try block within the body
2087 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002088 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002089
Tim Petersd7b5e882001-01-25 03:36:26 +00002090Standard library
2091
Barry Warsaw30dbd142001-01-31 22:14:01 +00002092- mailbox.py now has a new class, PortableUnixMailbox which is
2093 identical to UnixMailbox but uses a more portable scheme for
2094 determining From_ separators. Also, the constructors for all the
2095 classes in this module have a new optional `factory' argument, which
2096 is a callable used when new message classes must be instantiated by
2097 the next() method.
2098
Tim Petersd7b5e882001-01-25 03:36:26 +00002099- random.py is now self-contained, and offers all the functionality of
2100 the now-deprecated whrandom.py. See the docs for details. random.py
2101 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002102 and restoring the internal state of the generator; and jumpahead(n),
2103 for quickly forcing the internal state to be the same as if n calls to
2104 random() had been made. The latter is particularly useful for multi-
2105 threaded programs, creating one instance of the random.Random() class for
2106 each thread, then using .jumpahead() to force each instance to use a
2107 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002108
Tim Peters0de88fc2001-02-01 04:59:18 +00002109- random.py's seed() function is new. For bit-for-bit compatibility with
2110 prior releases, use the whseed function instead. The new seed function
2111 addresses two problems: (1) The old function couldn't produce more than
2112 about 2**24 distinct internal states; the new one about 2**45 (the best
2113 that can be done in the Wichmann-Hill generator). (2) The old function
2114 sometimes produced identical internal states when passed distinct
2115 integers, and there was no simple way to predict when that would happen;
2116 the new one guarantees to produce distinct internal states for all
2117 arguments in [0, 27814431486576L).
2118
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002119- The socket module now supports raw packets on Linux. The socket
2120 family is AF_PACKET.
2121
Tim Peters9ea17ac2001-02-02 05:57:15 +00002122- test_capi.py is a start at running tests of the Python C API. The tests
2123 are implemented by the new Modules/_testmodule.c.
2124
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002125- A new extension module, _symtable, provides provisional access to the
2126 internal symbol table used by the Python compiler. A higher-level
2127 interface will be added on top of _symtable in a future release.
2128
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002129- Removed the obsolete soundex module.
2130
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002131- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2132 the isSameNode method; NamedNodeMap the get method.
2133
2134- xml.sax.expatreader supports the lexical handler property; it
2135 generates comment, startCDATA, and endCDATA events.
2136
Tim Petersee826f82001-01-31 19:39:44 +00002137Windows changes
2138
2139- Build procedure: the zlib project is built in a different way that
2140 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002141 the zlib binary used. See PCbuild\readme.txt for details. Your old
2142 zlib-related directories can be deleted; you'll need to download fresh
2143 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002144
Tim Peters9ea17ac2001-02-02 05:57:15 +00002145- Build: New subproject _test for the benefit of test_capi.py (see above).
2146
Tim Petersb16c56f2001-02-02 21:24:51 +00002147- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2148 interface to some Python compiler internals).
2149
2150- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002151 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002152
Tim Petersa3a3a032000-11-30 05:22:44 +00002153What's New in Python 2.1 alpha 1?
2154=================================
2155
2156Core language, builtins, and interpreter
2157
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002158- There is a new Unicode companion to the PyObject_Str() API
2159 called PyObject_Unicode(). It behaves in the same way as the
2160 former, but assures that the returned value is an Unicode object
2161 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002162
Guido van Rossumf98eda02001-01-17 15:54:45 +00002163- The comparison operators support "rich comparison overloading" (PEP
2164 207). C extension types can provide a rich comparison function in
2165 the new tp_richcompare slot in the type object. The cmp() function
2166 and the C function PyObject_Compare() first try the new rich
2167 comparison operators before trying the old 3-way comparison. There
2168 is also a new C API PyObject_RichCompare() (which also falls back on
2169 the old 3-way comparison, but does not constrain the outcome of the
2170 rich comparison to a Boolean result).
2171
2172 The rich comparison function takes two objects (at least one of
2173 which is guaranteed to have the type that provided the function) and
2174 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2175 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2176 object, which may be NotImplemented (in which case the tp_compare
2177 slot function is used as a fallback, if defined).
2178
2179 Classes can overload individual comparison operators by defining one
2180 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002181 __ge__. There are no explicit "reflected argument" versions of
2182 these; instead, __lt__ and __gt__ are each other's reflection,
2183 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2184 reflection (similar at the C level). No other implications are
2185 made; in particular, Python does not assume that == is the Boolean
2186 inverse of !=, or that < is the Boolean inverse of >=. This makes
2187 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002188
2189 Classes or types that want to implement (in)equality tests but not
2190 the ordering operators (i.e. unordered types) should implement ==
2191 and !=, and raise an error for the ordering operators.
2192
Guido van Rossuma88479f2001-01-18 14:28:08 +00002193 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002194 Boolean; e.g. a matrix type might want to return a matrix of bits
2195 for A < B, giving elementwise comparisons. Such types should ensure
2196 that any interpretation of their value in a Boolean context raises
2197 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2198 at the C level) to always raise an exception.
2199
Guido van Rossuma88479f2001-01-18 14:28:08 +00002200- Complex numbers use rich comparisons to define == and != but raise
2201 an exception for <, <=, > and >=. Unfortunately, this also means
2202 that cmp() of two complex numbers raises an exception when the two
2203 numbers differ. Since it is not mathematically meaningful to compare
2204 complex numbers except for equality, I hope that this doesn't break
2205 too much code.
2206
Tim Peters3389f192001-02-18 08:48:49 +00002207- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002208 not defined by the language, other than that it's arbitrary but
2209 consistent (see the Reference Manual). An implementation detail changed
2210 in 2.1a1 such that None now compares less than any other object. Code
2211 relying on this new behavior (like code that relied on the previous
2212 behavior) does so at its own risk.
2213
Barry Warsaw573b5412001-01-15 20:43:18 +00002214- Functions and methods now support getting and setting arbitrarily
2215 named attributes (PEP 232). Functions have a new __dict__
2216 (a.k.a. func_dict) which hold the function attributes. Methods get
2217 and set attributes on their underlying im_func. It is a TypeError
2218 to set an attribute on a bound method.
2219
Guido van Rossum051e3352001-01-15 19:11:10 +00002220- The xrange() object implementation has been improved so that
2221 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2222 limitation that in this case len(xrange(sys.maxint)) can't be
2223 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2224 work fine as long as the index i doesn't actually reach 2**31.
2225 (Python uses regular ints for sequence and string indices; fixing
2226 that is much more work.)
2227
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002228- Two changes to from...import:
2229
Guido van Rossumba381232001-02-03 15:06:40 +00002230 1) "from M import X" now works even if (after loading module M)
2231 sys.modules['M'] is not a real module; it's basically a getattr()
2232 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002233
2234 2) "from M import *" now looks for M.__all__ to decide which names to
2235 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2236 filters out names starting with '_' as before. Whether or not
2237 __all__ exists, there's no restriction on the type of M.
2238
Guido van Rossumf61f1662001-01-10 20:13:55 +00002239- File objects have a new method, xreadlines(). This is the fastest
2240 way to iterate over all lines in a file:
2241
2242 for line in file.xreadlines():
2243 ...do something to line...
2244
2245 See the xreadlines module (mentioned below) for how to do this for
2246 other file-like objects.
2247
2248- Even if you don't use file.xreadlines(), you may expect a speedup on
2249 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002250 quite a bit in platform-specific ways: on systems (like Linux) that
2251 support flockfile(), getc_unlocked(), and funlockfile(), those are
2252 used by default. On systems (like Windows) without getc_unlocked(),
2253 a complicated (but still thread-safe) method using fgets() is used by
2254 default.
2255
Tim Petersd52269b2001-01-25 06:23:18 +00002256 You can force use of the fgets() method by #define'ing
2257 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002258 getc_unlocked()).
2259
Tim Petersd52269b2001-01-25 06:23:18 +00002260 You can force fgets() not to be used by #define'ing
2261 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002262 test_bufio.py fails -- and let us know if it does!).
2263
2264- In addition, the fileinput module, while still slower than the other
2265 methods on most platforms, has been sped up too, by using
2266 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002267
2268- Support for run-time warnings has been added, including a new
2269 command line option (-W) to specify the disposition of warnings.
2270 See the description of the warnings module below.
2271
2272- Extensive changes have been made to the coercion code. This mostly
2273 affects extension modules (which can now implement mixed-type
2274 numerical operators without having to use coercion), but
2275 occasionally, in boundary cases the coercion semantics have changed
2276 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002277 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002278 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002279 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002280
Guido van Rossumf98eda02001-01-17 15:54:45 +00002281- In connection with the coercion changes, a new built-in singleton
2282 object, NotImplemented is defined. This can be returned for
2283 operations that wish to indicate they are not implemented for a
2284 particular combination of arguments. From C, this is
2285 Py_NotImplemented.
2286
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002287- The interpreter accepts now bytecode files on the command line even
2288 if they do not have a .pyc or .pyo extension. On Linux, after executing
2289
Martin v. Löwise214baa2001-02-04 22:37:56 +00002290import imp,sys,string
2291magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2292reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2293open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002294
2295 any byte code file can be used as an executable (i.e. as an argument
2296 to execve(2)).
2297
Tim Peters9940b802000-12-01 07:59:35 +00002298- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002299 character. In 1.6 and earlier, they never produced a sign,
2300 and raised an error if the value of the long was too large
2301 to fit in a Python int. In 2.0, they produced a sign if and
2302 only if too large to fit in an int. This was inconsistent
2303 across platforms (because the size of an int varies across
2304 platforms), and inconsistent with hex() and oct(). Example:
2305
2306 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002307 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002308 'ffffffbe' # in 2.0 and before, on 32-bit machines
2309 >>> hex(-0x42L)
2310 '-0x42L' # in all versions of Python
2311
Tim Peters9940b802000-12-01 07:59:35 +00002312 The behavior of %d formats for negative Python longs remains
2313 the same as in 2.0 (although in 1.6 and before, they raised
2314 an error if the long didn't fit in a Python int).
2315
2316 %u formats don't make sense for Python longs, but are allowed
2317 and treated the same as %d in 2.1. In 2.0, a negative long
2318 formatted via %u produced a sign if and only if too large to
2319 fit in an int. In 1.6 and earlier, a negative long formatted
2320 via %u raised an error if it was too big to fit in an int.
2321
Guido van Rossum3661d392000-12-12 22:10:31 +00002322- Dictionary objects have an odd new method, popitem(). This removes
2323 an arbitrary item from the dictionary and returns it (in the form of
2324 a (key, value) pair). This can be useful for algorithms that use a
2325 dictionary as a bag of "to do" items and repeatedly need to pick one
2326 item. Such algorithms normally end up running in quadratic time;
2327 using popitem() they can usually be made to run in linear time.
2328
Tim Peters36cdad12000-12-29 02:06:45 +00002329Standard library
2330
Thomas Woutersfe385252001-01-19 23:16:56 +00002331- In the time module, the time argument to the functions strftime,
2332 localtime, gmtime, asctime and ctime is now optional, defaulting to
2333 the current time (in the local timezone).
2334
Guido van Rossumda91f222001-01-15 16:36:08 +00002335- The ftplib module now defaults to passive mode, which is deemed a
2336 more useful default given that clients are often inside firewalls
2337 these days. Note that this could break if ftplib is used to connect
2338 to a *server* that is inside a firewall, from outside; this is
2339 expected to be a very rare situation. To fix that, you can call
2340 ftp.set_pasv(0).
2341
Martin v. Löwis10a27872001-01-13 09:54:41 +00002342- The module site now treats .pth files not only for path configuration,
2343 but also supports extensions to the initialization code: Lines starting
2344 with import are executed.
2345
Guido van Rossumf61f1662001-01-10 20:13:55 +00002346- There's a new module, warnings, which implements a mechanism for
2347 issuing and filtering warnings. There are some new built-in
2348 exceptions that serve as warning categories, and a new command line
2349 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2350 turns warnings into errors). warnings.warn(message[, category])
2351 issues a warning message; this can also be called from C as
2352 PyErr_Warn(category, message).
2353
2354- A new module xreadlines was added. This exports a single factory
2355 function, xreadlines(). The intention is that this code is the
2356 absolutely fastest way to iterate over all lines in an open
2357 file(-like) object:
2358
2359 import xreadlines
2360 for line in xreadlines.xreadlines(file):
2361 ...do something to line...
2362
2363 This is equivalent to the previous the speed record holder using
2364 file.readlines(sizehint). Note that if file is a real file object
2365 (as opposed to a file-like object), this is equivalent:
2366
2367 for line in file.xreadlines():
2368 ...do something to line...
2369
Tim Peters36cdad12000-12-29 02:06:45 +00002370- The bisect module has new functions bisect_left, insort_left,
2371 bisect_right and insort_right. The old names bisect and insort
2372 are now aliases for bisect_right and insort_right. XXX_right
2373 and XXX_left methods differ in what happens when the new element
2374 compares equal to one or more elements already in the list: the
2375 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002376 right. Code that doesn't care where equal elements end up should
2377 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002378
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002379- The new curses.panel module wraps the panel library that forms part
2380 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2381
Guido van Rossumf61f1662001-01-10 20:13:55 +00002382- The SocketServer module now sets the allow_reuse_address flag by
2383 default in the TCPServer class.
2384
2385- A new function, sys._getframe(), returns the stack frame pointer of
2386 the caller. This is intended only as a building block for
2387 higher-level mechanisms such as string interpolation.
2388
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002389- The pyexpat module supports a number of new handlers, which are
2390 available only in expat 1.2. If invocation of a callback fails, it
2391 will report an additional frame in the traceback. Parser objects
2392 participate now in garbage collection. If expat reports an unknown
2393 encoding, pyexpat will try to use a Python codec; that works only
2394 for single-byte charsets. The parser type objects is exposed as
2395 XMLParserObject.
2396
2397- xml.dom now offers standard definitions for symbolic node type and
2398 exception code constants, and a hierarchy of DOM exceptions. minidom
2399 was adjusted to use them.
2400
2401- The conformance of xml.dom.minidom to the DOM specification was
2402 improved. It detects a number of additional error cases; the
2403 previous/next relationship works even when the tree is modified;
2404 Node supports the normalize() method; NamedNodeMap, DocumentType and
2405 DOMImplementation classes were added; Element supports the
2406 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2407 method.
2408
Guido van Rossumf61f1662001-01-10 20:13:55 +00002409Build issues
2410
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002411- For Unix (and Unix-compatible) builds, configuration and building of
2412 extension modules is now greatly automated. Rather than having to
2413 edit the Modules/Setup file to indicate which modules should be
2414 built and where their include files and libraries are, a
2415 distutils-based setup.py script now takes care of building most
2416 extension modules. All extension modules built this way are built
2417 as shared libraries. Only a few modules that must be linked
2418 statically are still listed in the Setup file; you won't need to
2419 edit their configuration.
2420
2421- Python should now build out of the box on Cygwin. If it doesn't,
2422 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002423
2424- Python now always uses its own (renamed) implementation of getopt()
2425 -- there's too much variation among C library getopt()
2426 implementations.
2427
2428- C++ compilers are better supported; the CXX macro is always set to a
2429 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002430
Tim Petersd92dfe02000-12-12 01:18:41 +00002431Windows changes
2432
2433- select module: By default under Windows, a select() call
2434 can specify no more than 64 sockets. Python now boosts
2435 this Microsoft default to 512. If you need even more than
2436 that, see the MS docs (you'll need to #define FD_SETSIZE
2437 and recompile Python from source).
2438
Guido van Rossumf61f1662001-01-10 20:13:55 +00002439- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2440 subdirectory is no more!
2441
Tim Petersa3a3a032000-11-30 05:22:44 +00002442
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002443What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002444=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002445
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002446Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002447changes are in the file HISTORY. If you are making the jump directly
2448from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2449HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002450
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002451Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2452the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2453http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002454
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002455--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002456
2457======================================================================
2458
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002459What's new in 2.0 (since release candidate 1)?
2460==============================================
2461
2462Standard library
2463
2464- The copy_reg module was modified to clarify its intended use: to
2465 register pickle support for extension types, not for classes.
2466 pickle() will raise a TypeError if it is passed a class.
2467
2468- Fixed a bug in gettext's "normalize and expand" code that prevented
2469 it from finding an existing .mo file.
2470
2471- Restored support for HTTP/0.9 servers in httplib.
2472
Tim Peters989b7b92000-10-16 20:24:53 +00002473- The math module was changed to stop raising OverflowError in case of
2474 underflow, and return 0 instead in underflow cases. Whether Python
2475 used to raise OverflowError in case of underflow was platform-
2476 dependent (it did when the platform math library set errno to ERANGE
2477 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002478
2479- Fixed a bug in StringIO that occurred when the file position was not
2480 at the end of the file and write() was called with enough data to
2481 extend past the end of the file.
2482
2483- Fixed a bug that caused Tkinter error messages to get lost on
2484 Windows. The bug was fixed by replacing direct use of
2485 interp->result with Tcl_GetStringResult(interp).
2486
2487- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2488 redirect response.
2489
2490- Several changes were made to distutils: Some debugging code was
2491 removed from util. Fixed the installer used when an external zip
2492 program (like WinZip) is not found; the source code for this
2493 installer is in Misc/distutils. check_lib() was modified to behave
2494 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2495 test for whether installed modules are on sys.path was changed to
2496 use both normcase() and normpath().
2497
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002498- Several minor bugs were fixed in the xml package (the minidom,
2499 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002500
2501- The regression test driver (regrtest.py) behavior when invoked with
2502 -l changed: It now reports a count of objects that are recognized as
2503 garbage but not freed by the garbage collector.
2504
Tim Peters989b7b92000-10-16 20:24:53 +00002505- The regression test for the math module was changed to test
2506 exceptional behavior when the test is run in verbose mode. Python
2507 cannot yet guarantee consistent exception behavior across platforms,
2508 so the exception part of test_math is run only in verbose mode, and
2509 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002510
2511Internals
2512
2513- PyOS_CheckStack() has been disabled on Win64, where it caused
2514 test_sre to fail.
2515
2516Build issues
2517
2518- Changed compiler flags, so that gcc is always invoked with -Wall and
2519 -Wstrict-prototypes. Users compiling Python with GCC should see
2520 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002521 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002522 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002523
Tim Petersa3a3a032000-11-30 05:22:44 +00002524- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002525
2526Tools and other miscellany
2527
2528- The compiler in Tools/compiler was updated to support the new
2529 language features introduced in 2.0: extended print statement, list
2530 comprehensions, and augmented assignments. The new compiler should
2531 also be backwards compatible with Python 1.5.2; the compiler will
2532 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002533 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002534
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002535What's new in 2.0 release candidate 1 (since beta 2)?
2536=====================================================
2537
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002538What is release candidate 1?
2539
2540We believe that release candidate 1 will fix all known bugs that we
2541intend to fix for the 2.0 final release. This release should be a bit
2542more stable than the previous betas. We would like to see even more
2543widespread testing before the final release, so we are producing this
2544release candidate. The final release will be exactly the same unless
2545any show-stopping (or brown bag) bugs are found by testers of the
2546release candidate.
2547
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002548All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002549to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002550
2551Core language, builtins, and interpreter
2552
2553- A bug that caused crashes when __coerce__ was used with augmented
2554 assignment, e.g. +=, was fixed.
2555
2556- Raise ZeroDivisionError when raising zero to a negative number,
2557 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2558 power operator and the result of math.pow(0.0, -2.0) will vary by
2559 platform. On Linux, it raises a ValueError.
2560
2561- A bug in Unicode string interpolation was fixed that occasionally
2562 caused errors with formats including "%%". For example, the
2563 following expression "%% %s" % u"abc" no longer raises a TypeError.
2564
2565- Compilation of deeply nested expressions raises MemoryError instead
2566 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2567
2568- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2569 rendering them useless. They are now written in binary mode again.
2570
2571Standard library
2572
2573- Keyword arguments are now accepted for most pattern and match object
2574 methods in SRE, the standard regular expression engine.
2575
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002576- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002577 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002578
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002579- Several bugs in the Unicode handling and error handling in _tkinter
2580 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002581
2582- Fix memory management errors in Merge() and Tkapp_Call() routines.
2583
2584- Several changes were made to cStringIO to make it compatible with
2585 the file-like object interface and with StringIO. If operations are
2586 performed on a closed object, an exception is raised. The truncate
2587 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002588 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002589
2590- There were many changes made to the linuxaudiodev module and its
2591 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002592 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002593
2594 Note that this module is named poorly, because it should work
2595 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002596 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002597
2598 The module now raises exceptions when errors occur instead of
2599 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2600 audio) and defines a getptr() method that calls the
2601 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2602
2603- The library_version attribute, introduced in an earlier beta, was
2604 removed because it can not be supported with early versions of the C
2605 readline library, which provides no way to determine the version at
2606 compile-time.
2607
2608- The binascii module is now enabled on Win64.
2609
Tim Peters46446d62000-10-09 21:19:31 +00002610- tokenize.py no longer suffers "recursion depth" errors when parsing
2611 programs with very long string literals.
2612
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002613Internals
2614
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002615- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002616 which is called when the interpreter starts up to determine where
2617 the standard library is installed. These vulnerabilities affect all
2618 previous versions of Python and can be exploited by setting very
2619 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2620 setuid Python script, although use of the wrapper in
2621 Misc/setuid-prog.c will eliminate the vulnerability.
2622
2623- Fixed garbage collection bugs in instance creation that were
2624 triggered when errors occurred during initialization. The solution,
2625 applied in cPickle and in PyInstance_New(), is to call
2626 PyObject_GC_Init() after the initialization of the object's
2627 container attributes is complete.
2628
2629- pyexpat adds definitions of PyModule_AddStringConstant and
2630 PyModule_AddObject if the Python version is less than 2.0, which
2631 provides compatibility with PyXML on Python 1.5.2.
2632
2633- If the platform has a bogus definition for LONG_BIT (the number of
2634 bits in a long), an error will be reported at compile time.
2635
2636- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2637 collection crashes and possibly other, unreported crashes.
2638
2639- Fixed a memory leak in _PyUnicode_Fini().
2640
2641Build issues
2642
2643- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002644 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002645 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002646
2647- The mmap.PAGESIZE constant is now initialized using sysconf when
2648 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2649
2650- The md5 file should now compile on all platforms.
2651
2652- The select module now compiles on platforms that do not define
2653 POLLRDNORM and related constants.
2654
2655- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002656 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002657
Jeremy Hylton10921202000-10-09 18:34:12 +00002658- BeOS: A number of changes were made to the build and installation
2659 process. ar-fake now operates on a directory of object files.
2660 dl_export.h is gone, and its macros now appear on the mwcc command
2661 line during build on PPC BeOS.
2662
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002663- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002664 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002665
2666- Cygwin: Support for shared libraries, Tkinter, and sockets.
2667
2668- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2669
2670Tools and other miscellany
2671
2672- Removed debugging prints from main used with freeze.
2673
Tim Peters46446d62000-10-09 21:19:31 +00002674- IDLE auto-indent no longer crashes when it encounters Unicode
2675 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002676
2677What's new in 2.0 beta 2 (since beta 1)?
2678========================================
2679
2680Core language, builtins, and interpreter
2681
Tim Peters482c0212000-09-26 06:33:09 +00002682- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002683 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002684
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002685- Add -h and -V command line options to print the usage message and
2686 Python version number and exit immediately.
2687
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002688- eval() and exec accept Unicode objects as code parameters.
2689
2690- getattr() and setattr() now also accept Unicode objects for the
2691 attribute name, which are converted to strings using the default
2692 encoding before lookup.
2693
2694- Multiplication on string and Unicode now does proper bounds
2695 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2696 string is too long."
2697
2698- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002699 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002700
Jeremy Hylton1b618592000-09-26 05:32:36 +00002701
2702Standard library and extensions
2703
Guido van Rossum5b08f132001-04-16 02:05:23 +00002704- socket module: the OpenSSL code now adds support for RAND_status()
2705 and EGD (Entropy Gathering Device).
2706
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002707- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002708 argument checking; it still takes no arguments.
2709
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002710- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002711
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002712- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002713
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002714- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002715
2716- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002717 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718
2719- copy: Copy Unicode objects atomically.
2720
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002721- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002722
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002723- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002724
Fred Drake67233bc2000-09-26 16:40:27 +00002725- dbm: Add get() and setdefault() methods to dbm object. Add constant
2726 `library' to module that names the library used. Added doc strings
2727 and method names to error messages. Uses configure to determine
2728 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2729 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002730
2731- distutils: Update to version 0.9.3.
2732
2733- dl: Add several dl.RTLD_ constants.
2734
2735- fpectl: Now supported on FreeBSD.
2736
2737- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2738 found by the collector will be saved in gc.garbage. This is useful
2739 for debugging a program that creates reference cycles.
2740
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002741- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002742 of HTTP class. Do not close socket on zero-length response. Do not
2743 crash when server sends invalid content-length header.
2744
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002745- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002746
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002747- marshal: When reading a short, sign-extend on platforms where shorts
2748 are bigger than 16 bits. When reading a long, repair the unportable
2749 sign extension that was being done for 64-bit machines. (It assumed
2750 that signed right shift sign-extends.)
2751
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002752- operator: Add contains(), invert(), __invert__() as aliases for
2753 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002754
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002755- os: Add support for popen2() and popen3() on all platforms where
2756 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002757
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002758- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002759 clicking on a file in Explorer (or passing the file name to the
2760 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002761
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002762- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002763 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002764
2765- pickle: Now raises ValueError when an invalid pickle that contains
2766 a non-string repr where a string repr was expected. This behavior
2767 matches cPickle.
2768
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002769- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002770
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002771- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002772
2773- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002774 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002775 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002776
2777- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002778 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002779
2780- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002781 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002782 few cycles during startup since the first call to
2783 setdefaultencoding() will initialize the codec registry and the
2784 encodings package.
2785
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002786- socket: Support for size hint in readlines() method of object returned
2787 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002788
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002789- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002790 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002791 is followed by whitespace.
2792
Tim Petersa3a3a032000-11-30 05:22:44 +00002793- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002794
2795- struct: Check ranges for bytes and shorts.
2796
2797- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002798 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002799
2800- Tkinter: Image objects are now guaranteed to have unique ids. Set
2801 event.delta to zero if Tk version doesn't support mousewheel.
2802 Removed some debugging prints.
2803
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002804- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002805
Fred Drake67233bc2000-09-26 16:40:27 +00002806- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002807 which works around a bug in Norton AntiVirus 2000 that leads directly
2808 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002809
2810- xml: New version detection code allows PyXML to override standard
2811 XML package if PyXML version is greater than 0.6.1.
2812
Fred Drake64bb3802000-09-26 16:21:35 +00002813- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2814 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2815 tree only for nodes which are sufficiently interesting to a specific
2816 application. Does not provide the HTML-specific extensions. Still
2817 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002818
Fred Drake64bb3802000-09-26 16:21:35 +00002819- xml.sax: SAX 2 support for Python, including all the handler
2820 interfaces needed to process XML 1.0 compliant XML. Some
2821 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002822
Fred Drake64bb3802000-09-26 16:21:35 +00002823- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2824 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002825
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002826
Jeremy Hylton1b618592000-09-26 05:32:36 +00002827C API
2828
2829- Add three new convenience functions for module initialization --
2830 PyModule_AddObject(), PyModule_AddIntConstant(), and
2831 PyModule_AddStringConstant().
2832
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002833- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002834 removed and add #error to Python.h if NULL isn't defined after
2835 #include of stdio.h.
2836
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002837- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002838 backwards compatibility (at the source level) with old extensions.
2839
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002840- A wrapper API was added for signal() and sigaction(). Instead of
2841 either function, always use PyOS_getsig() to get a signal handler
2842 and PyOS_setsig() to set one. A new convenience typedef
2843 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002844
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002845- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002846 internal data buffer and size of a string object -- or the default
2847 encoded version of a Unicode object.
2848
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002849- PyString_Size() and PyString_AsString() accept Unicode objects.
2850
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002851- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002852 exists). INT_MAX and LONG_MAX will always be defined, even if
2853 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002854
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002855- PyFloat_FromString takes a second argument, pend, that was
2856 effectively useless. It is now officially useless but preserved for
2857 backwards compatibility. If the pend argument is not NULL, *pend is
2858 set to NULL.
2859
2860- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2861 for the attribute name. See note on getattr() above.
2862
2863- A few bug fixes to argument processing for Unicode.
2864 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2865 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2866 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002867 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002868
2869- Py_BuildValue accepts B format (for bgen-generated code).
2870
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002871
Jeremy Hylton1b618592000-09-26 05:32:36 +00002872Internals
2873
2874- On Unix, fix code for finding Python installation directory so that
2875 it works when argv[0] is a relative path.
2876
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002877- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002878 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002879 rather than by generating a copy of the object.
2880
Tim Peters482c0212000-09-26 06:33:09 +00002881- Several of the internal Unicode tables are much smaller now, and
2882 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002883
Jeremy Hylton97693b02000-09-26 17:42:51 +00002884- In the garbage collector: Fixed bug in collection of tuples. Fixed
2885 bug that caused some instances to be removed from the container set
2886 while they were still live. Fixed parsing in gc.set_debug() for
2887 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002888
2889- Fixed refcount problem in instance deallocation that only occurred
2890 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2891
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002892- On Windows, getpythonregpath is now protected against null data in
2893 registry key.
2894
2895- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002896 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002897
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002898
Jeremy Hylton1b618592000-09-26 05:32:36 +00002899Build and platform-specific issues
2900
2901- Better support of GNU Pth via --with-pth configure option.
2902
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002903- Python/C API now properly exposed to dynamically-loaded extension
2904 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002905
2906- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2907 Don't define MS_SYNC to be zero when it is undefined. Added missing
2908 prototypes in posixmodule.c.
2909
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002910- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002911 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002912
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002913- Fix largefile support on older NetBSD systems and OpenBSD by adding
2914 define for TELL64.
2915
2916
2917Tools and other miscellany
2918
2919- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2920
2921- freeze: The modulefinder now works with 2.0 opcodes.
2922
Tim Petersa3a3a032000-11-30 05:22:44 +00002923- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002924 Move hackery of sys.argv until after the Tk instance has been
2925 created, which allows the application-specific Tkinter
2926 initialization to be executed if present; also pass an explicit
2927 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002928
Jeremy Hylton1b618592000-09-26 05:32:36 +00002929
2930What's new in 2.0 beta 1?
2931=========================
2932
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002933Source Incompatibilities
2934------------------------
2935
2936None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2937such as single-argument append(), connect() and bind(), and changes to
2938str(long) and repr(float).
2939
2940
2941Binary Incompatibilities
2942------------------------
2943
2944- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2945with Python 2.0; these extensions will have to be rebuilt for Python
29462.0.
2947
2948- On Windows, attempting to import a third party extension built for
2949Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2950can do about this. Check your PYTHONPATH environment variable!
2951
2952- Python bytecode files (*.pyc and *.pyo) are not compatible between
2953releases.
2954
2955
2956Overview of Changes Since 1.6
2957-----------------------------
2958
2959There are many new modules (including brand new XML support through
2960the xml package, and i18n support through the gettext module); a list
2961of all new modules is included below. Lots of bugs have been fixed.
2962
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002963The process for making major new changes to the language has changed
2964since Python 1.6. Enhancements must now be documented by a Python
2965Enhancement Proposal (PEP) before they can be accepted.
2966
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002967There are several important syntax enhancements, described in more
2968detail below:
2969
2970 - Augmented assignment, e.g. x += 1
2971
2972 - List comprehensions, e.g. [x**2 for x in range(10)]
2973
2974 - Extended import statement, e.g. import Module as Name
2975
2976 - Extended print statement, e.g. print >> file, "Hello"
2977
2978Other important changes:
2979
2980 - Optional collection of cyclical garbage
2981
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002982Python Enhancement Proposal (PEP)
2983---------------------------------
2984
2985PEP stands for Python Enhancement Proposal. A PEP is a design
2986document providing information to the Python community, or describing
2987a new feature for Python. The PEP should provide a concise technical
2988specification of the feature and a rationale for the feature.
2989
2990We intend PEPs to be the primary mechanisms for proposing new
2991features, for collecting community input on an issue, and for
2992documenting the design decisions that have gone into Python. The PEP
2993author is responsible for building consensus within the community and
2994documenting dissenting opinions.
2995
2996The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002997
2998Augmented Assignment
2999--------------------
3000
3001This must have been the most-requested feature of the past years!
3002Eleven new assignment operators were added:
3003
Guido van Rossume905e952000-09-05 12:42:46 +00003004 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003005
3006For example,
3007
3008 A += B
3009
3010is similar to
3011
3012 A = A + B
3013
3014except that A is evaluated only once (relevant when A is something
3015like dict[index].attr).
3016
3017However, if A is a mutable object, A may be modified in place. Thus,
3018if A is a number or a string, A += B has the same effect as A = A+B
3019(except A is only evaluated once); but if a is a list, A += B has the
3020same effect as A.extend(B)!
3021
3022Classes and built-in object types can override the new operators in
3023order to implement the in-place behavior; the not-in-place behavior is
3024used automatically as a fallback when an object doesn't implement the
3025in-place behavior. For classes, the method name is derived from the
3026method name for the corresponding not-in-place operator by inserting
3027an 'i' in front of the name, e.g. __iadd__ implements in-place
3028__add__.
3029
3030Augmented assignment was implemented by Thomas Wouters.
3031
3032
3033List Comprehensions
3034-------------------
3035
3036This is a flexible new notation for lists whose elements are computed
3037from another list (or lists). The simplest form is:
3038
3039 [<expression> for <variable> in <sequence>]
3040
Guido van Rossum56db0952000-09-06 23:34:25 +00003041For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003042This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003043
3044You can also add a condition:
3045
3046 [<expression> for <variable> in <sequence> if <condition>]
3047
3048For example, [w for w in words if w == w.lower()] would yield the list
3049of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003050than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003051
3052You can also have nested for loops and more than one 'if' clause. For
3053example, here's a function that flattens a sequence of sequences::
3054
3055 def flatten(seq):
3056 return [x for subseq in seq for x in subseq]
3057
3058 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3059
3060This prints
3061
3062 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3063
3064List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003065Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003066
3067
3068Extended Import Statement
3069-------------------------
3070
3071Many people have asked for a way to import a module under a different
3072name. This can be accomplished like this:
3073
3074 import foo
3075 bar = foo
3076 del foo
3077
3078but this common idiom gets old quickly. A simple extension of the
3079import statement now allows this to be written as follows:
3080
3081 import foo as bar
3082
3083There's also a variant for 'from ... import':
3084
3085 from foo import bar as spam
3086
3087This also works with packages; e.g. you can write this:
3088
3089 import test.regrtest as regrtest
3090
3091Note that 'as' is not a new keyword -- it is recognized only in this
3092context (this is only possible because the syntax for the import
3093statement doesn't involve expressions).
3094
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003095Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003096
3097
3098Extended Print Statement
3099------------------------
3100
3101Easily the most controversial new feature, this extension to the print
3102statement adds an option to make the output go to a different file
3103than the default sys.stdout.
3104
3105For example, to write an error message to sys.stderr, you can now
3106write:
3107
3108 print >> sys.stderr, "Error: bad dog!"
3109
3110As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003111evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003112
3113 print >> None, "Hello world"
3114
3115is equivalent to
3116
3117 print "Hello world"
3118
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003119Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003120
3121
3122Optional Collection of Cyclical Garbage
3123---------------------------------------
3124
3125Python is now equipped with a garbage collector that can hunt down
3126cyclical references between Python objects. It's no replacement for
3127reference counting; in fact, it depends on the reference counts being
3128correct, and decides that a set of objects belong to a cycle if all
3129their reference counts can be accounted for from their references to
3130each other. This devious scheme was first proposed by Eric Tiedemann,
3131and brought to implementation by Neil Schemenauer.
3132
3133There's a module "gc" that lets you control some parameters of the
3134garbage collection. There's also an option to the configure script
3135that lets you enable or disable the garbage collection. In 2.0b1,
3136it's on by default, so that we (hopefully) can collect decent user
3137experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003138performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003139off by default in the final 2.0 release.
3140
3141
3142Smaller Changes
3143---------------
3144
3145A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3146map(None, seq1, seq2, ...) when the sequences have the same length;
3147i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3148the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003149zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003150
3151sys.version_info is a tuple (major, minor, micro, level, serial).
3152
3153Dictionaries have an odd new method, setdefault(key, default).
3154dict.setdefault(key, default) returns dict[key] if it exists; if not,
3155it sets dict[key] to default and returns that value. Thus:
3156
3157 dict.setdefault(key, []).append(item)
3158
3159does the same work as this common idiom:
3160
3161 if not dict.has_key(key):
3162 dict[key] = []
3163 dict[key].append(item)
3164
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003165There are two new variants of SyntaxError that are raised for
3166indentation-related errors: IndentationError and TabError.
3167
3168Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3169escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003170
3171The limits on the size of expressions and file in Python source code
3172have been raised from 2**16 to 2**32. Previous versions of Python
3173were limited because the maximum argument size the Python VM accepted
3174was 2**16. This limited the size of object constructor expressions,
3175e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3176limit was raised thanks to a patch by Charles Waldman that effectively
3177fixes the problem. It is now much more likely that you will be
3178limited by available memory than by an arbitrary limit in Python.
3179
3180The interpreter's maximum recursion depth can be modified by Python
3181programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3182limit is the maximum number of recursive calls that can be made by
3183Python code. The limit exists to prevent infinite recursion from
3184overflowing the C stack and causing a core dump. The default value is
31851000. The maximum safe value for a particular platform can be found
3186by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003187
3188New Modules and Packages
3189------------------------
3190
3191atexit - for registering functions to be called when Python exits.
3192
3193imputil - Greg Stein's alternative API for writing custom import
3194hooks.
3195
3196pyexpat - an interface to the Expat XML parser, contributed by Paul
3197Prescod.
3198
3199xml - a new package with XML support code organized (so far) in three
3200subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3201would fill a volume. There's a special feature whereby a
3202user-installed package named _xmlplus overrides the standard
3203xmlpackage; this is intended to give the XML SIG a hook to distribute
3204backwards-compatible updates to the standard xml package.
3205
3206webbrowser - a platform-independent API to launch a web browser.
3207
3208
Guido van Rossume905e952000-09-05 12:42:46 +00003209Changed Modules
3210---------------
3211
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003212array -- new methods for array objects: count, extend, index, pop, and
3213remove
3214
3215binascii -- new functions b2a_hex and a2b_hex that convert between
3216binary data and its hex representation
3217
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003218calendar -- Many new functions that support features including control
3219over which day of the week is the first day, returning strings instead
3220of printing them. Also new symbolic constants for days of week,
3221e.g. MONDAY, ..., SUNDAY.
3222
3223cgi -- FieldStorage objects have a getvalue method that works like a
3224dictionary's get method and returns the value attribute of the object.
3225
3226ConfigParser -- The parser object has new methods has_option,
3227remove_section, remove_option, set, and write. They allow the module
3228to be used for writing config files as well as reading them.
3229
3230ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003231optionally support the RFC 959 REST command.
3232
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003233gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003234
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003235httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3236the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003237
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003238locale -- implement getdefaultlocale for Win32 and Macintosh
3239
3240marshal -- no longer dumps core when marshaling deeply nested or
3241recursive data structures
3242
3243os -- new functions isatty, seteuid, setegid, setreuid, setregid
3244
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003245os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3246support under Unix.
3247
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003248os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003249
3250os.path -- fix semantics of os.path.commonprefix
3251
3252smtplib -- support for sending very long messages
3253
3254socket -- new function getfqdn()
3255
3256readline -- new functions to read, write and truncate history files.
3257The readline section of the library reference manual contains an
3258example.
3259
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003260select -- add interface to poll system call
3261
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003262shutil -- new copyfileobj function
3263
3264SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3265HTTP server.
3266
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003267Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003268
3269urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003270e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003271
3272whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003273
3274
3275Obsolete Modules
3276----------------
3277
3278None. However note that 1.6 made a whole slew of modules obsolete:
3279stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3280poly, zmod, strop, util, whatsound.
3281
3282
3283Changed, New, Obsolete Tools
3284----------------------------
3285
Tim Peters8b092332000-09-05 20:15:25 +00003286None.
Guido van Rossume905e952000-09-05 12:42:46 +00003287
3288
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003289C-level Changes
3290---------------
3291
3292Several cleanup jobs were carried out throughout the source code.
3293
3294All C code was converted to ANSI C; we got rid of all uses of the
3295Py_PROTO() macro, which makes the header files a lot more readable.
3296
3297Most of the portability hacks were moved to a new header file,
3298pyport.h; several other new header files were added and some old
3299header files were removed, in an attempt to create a more rational set
3300of header files. (Few of these ever need to be included explicitly;
3301they are all included by Python.h.)
3302
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003303Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003304and Win64, especially for the new Intel Itanium processor. Mick also
3305added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003306
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003307The C APIs to return an object's size have been update to consistently
3308use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3309previous versions, the abstract interfaces used PyXXX_Length and the
3310concrete interfaces used PyXXX_Size. The old names,
3311e.g. PyObject_Length, are still available for backwards compatibility
3312at the API level, but are deprecated.
3313
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003314The PyOS_CheckStack function has been implemented on Windows by
3315Fredrik Lundh. It prevents Python from failing with a stack overflow
3316on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003317
3318The GC changes resulted in creation of two new slots on object,
3319tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003320the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003321
3322The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003323C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003324
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003325PyErr_Format has been updated to automatically calculate the size of
3326the buffer needed to hold the formatted result string. This change
3327prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003328
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003329New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003330
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003331PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3332that are the same as their non-Ex counterparts except they take an
3333extra flag argument that tells them to close the file when done.
3334
3335XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003336
Tim Peters8b092332000-09-05 20:15:25 +00003337
3338Windows Changes
3339---------------
3340
3341New popen2/popen3/peopen4 in os module (see Changed Modules above).
3342
3343os.popen is much more usable on Windows 95 and 98. See Microsoft
3344Knowledge Base article Q150956. The Win9x workaround described there
3345is implemented by the new w9xpopen.exe helper in the root of your
3346Python installation. Note that Python uses this internally; it is not
3347a standalone program.
3348
3349Administrator privileges are no longer required to install Python
3350on Windows NT or Windows 2000. If you have administrator privileges,
3351Python's registry info will be written under HKEY_LOCAL_MACHINE.
3352Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003353under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003354uses of Python, but will prevent some advanced uses from working
3355(for example, running a Python script as an NT service, or possibly
3356from CGI).
3357
3358[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3359installer; instead, it installs the needed Tcl/Tk files directly in the
3360Python directory. If you already have a Tcl/Tk installation, this
3361wastes some disk space (about 4 Megs) but avoids problems with
3362conflicting Tcl/Tk installations, and makes it much easier for Python
3363to ensure that Tcl/Tk can find all its files.
3364
3365[This was new in 1.6] The Windows installer now installs by default in
3366\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3367
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003368
3369Updates to the changes between 1.5.2 and 1.6
3370--------------------------------------------
3371
3372The 1.6 NEWS file can't be changed after the release is done, so here
3373is some late-breaking news:
3374
3375New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3376and changes to getlocale() and setlocale().
3377
3378The new module is now enabled per default.
3379
3380It is not true that the encodings codecs cannot be used for normal
3381strings: the string.encode() (which is also present on 8-bit strings
3382!) allows using them for 8-bit strings too, e.g. to convert files from
3383cp1252 (Windows) to latin-1 or vice-versa.
3384
3385Japanese codecs are available from Tamito KAJIYAMA:
3386http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3387
3388
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003389======================================================================