blob: 8c424604c54cba560501f5731ea3239e90635975 [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 Rossum181e41a2002-04-06 00:23:25 +00009- Fixed super() to work correctly with class methods. [SF bug #535444]
10
Guido van Rossum47834462002-04-04 15:21:33 +000011- A new built-in type, bool, has been added, as well as built-in
12 names for its two values, True and False. Comparisons and sundry
13 other operations that return a truth value have been changed to
14 return a bool instead. Read PEP 285 for an explanantion of why this
15 is backward compatible.
16
Guido van Rossum95b62a62002-03-29 01:07:24 +000017- Fixed two bugs reported as SF #535905: under certain conditions,
18 deallocating a deeply nested structure could cause a segfault in the
19 garbage collector, due to interaction with the "trashcan" code;
20 access to the current frame during destruction of a local variable
21 could access a pointer to freed memory.
22
Neil Schemenauer9d50d132002-03-22 17:06:59 +000023- The optional object allocator has been enabled by default.
24
Guido van Rossum8c842552002-03-14 23:05:54 +000025- If you try to pickle an instance of a class that has __slots__ but
26 doesn't define or override __getstate__, a TypeError is now raised.
27 This is done by adding a bozo __getstate__ to the class that always
28 raises TypeError. (Before, this would appear to be pickled, but the
29 state of the slots would be lost.)
30
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000031- PyErr_Display will provide file and line information for all exceptions
32 that have an attribute print_file_and_line, not just SyntaxErrors.
33
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000034- The UTF-8 codec will now encode and decode Unicode surrogates
35 correctly and without raising exceptions for unpaired ones.
36
Neal Norwitz649b7592002-01-01 19:07:13 +000037- file.xreadlines() now raises a ValueError if the file is closed:
38 Previously, an xreadlines object was returned which would raise
39 a ValueError when the xreadlines.next() method was called.
40
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000041- posix.killpg has been added where available.
42
Neal Norwitz0c766a02002-03-27 13:03:09 +000043- sys.exit() inadvertantly allowed more than one argument.
44 An exception will now be raised if more than one argument is used.
45
Tim Petersaf8446f2001-12-21 21:36:50 +000046Extension modules
47
Martin v. Löwis2e64c342002-03-27 18:49:02 +000048- The locale module now exposes the C library's gettext interface.
49
Tim Petersfbf74f22002-03-14 19:06:01 +000050- A security hole ("double free") was found in zlib-1.1.3, a popular
51 third party compression library used by some Python modules. The
52 hole was quickly plugged in zlib-1.1.4, and the Windows build of
53 Python now ships with zlib-1.1.4.
54
Martin v. Löwis29001ff2002-03-01 10:47:37 +000055- pwd and grp return enhanced tuples now, with symbolic field names.
56
Martin v. Löwis99866332002-03-01 10:27:01 +000057- array.array is now a type object. A new format character
58 'u' indicates Py_UNICODE arrays. For those, .tounicode and
59 .fromunicode methods are available. Arrays now support __iadd__
60 and __imul__.
61
Neal Norwitze790eae2002-01-01 21:14:12 +000062- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000063 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
64 is called.
65
Tim Petersaf8446f2001-12-21 21:36:50 +000066Library
67
Marc-André Lemburg4179a012002-04-05 12:15:05 +000068- The UTF-16, -LE and -BE now raise a NotImplementedError
69 for all calls to .readline(). Previously, they used to just
70 produce garbage or fail with an encoding error -- UTF-16 is
71 a 2-byte encoding and the C lib's line reading APIs don't
72 work well with these.
73
Martin v. Löwis5c137c22002-03-18 12:44:08 +000074- compileall now supports quiet operation.
75
Martin v. Löwis587c98c2002-03-17 18:37:22 +000076- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
77 connections.
78
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000079- socket module: the SSL support was broken out of the main
80 _socket module C helper and placed into a new _ssl helper
81 which now gets imported by socket.py if available and working.
82
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000083- encodings package: added aliases for all supported IANA character
84 sets
85
Guido van Rossum606fe4e2001-12-28 20:57:14 +000086- ftplib: to safeguard the user's privacy, anonymous login will use
87 "anonymous@" as default password, rather than the real user and host
88 name.
89
Fred Drake36736122002-01-10 13:50:31 +000090- webbrowser: tightened up the command passed to os.system() so that
91 arbitrary shell code can't be executed because a bogus URL was
92 passed in.
93
Tim Peters11bd9942002-02-01 00:52:29 +000094- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000095 gettext.find an optional all argument. Translations will now fallback
96 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000097
Martin v. Löwis9668b932002-01-12 11:27:42 +000098- distutils bdist commands now offer a --skip-build option.
99
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000100- warnings.warn now accepts a Warning instance as first argument.
101
Fred Drakefed7e852002-04-04 19:36:15 +0000102- The xml.sax.expatreader.ExpatParser class will no longer create
103 circular references by using itself as the locator that gets passed
104 to the content handler implementation. [SF bug #535474]
105
Tim Petersaf8446f2001-12-21 21:36:50 +0000106Tools/Demos
107
Marc-André Lemburg46260092002-04-04 16:17:11 +0000108- freeze.py now produces binaries which can import shared modules,
109 unlike before when this failed due to missing symbol exports in
110 the generated binary.
111
Tim Petersaf8446f2001-12-21 21:36:50 +0000112Build
113
Martin v. Löwis1142de32002-03-29 16:28:31 +0000114- On Unix, a shared libpython2.3.so can be created with --enable-shared.
115
Tim Peters8deda702002-03-30 10:06:07 +0000116- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
117 preprocessor symbols were eliminated. The internal decisions they
118 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000119
Tim Petersaf8446f2001-12-21 21:36:50 +0000120C API
121
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000122- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
123 functions will be allocated using pymalloc if it is enabled. These
124 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
125 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
126 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
127 PyCore_* family of APIs have been removed.
128
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000129- The "u#" parser marker will now pass through Unicode object as-is
130 without going through the buffer API.
131
Martin v. Löwis7198a522002-01-01 19:59:11 +0000132- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
133
Tim Peters10a3bb52001-12-25 19:07:38 +0000134- An old #define of ANY as void has been removed from pyport.h. This
135 hasn't been used since Python's pre-ANSI days, and the #define has
136 been marked as obsolete since then. SF bug 495548 says it created
137 conflicts with other packages, so keeping it around wasn't harmless.
138
Tim Petersaf8446f2001-12-21 21:36:50 +0000139- Because Python's magic number scheme broke on January 1st, we decided
140 to stop Python development. Thanks for all the fish!
141
Tim Petersfb05db22002-03-11 00:24:00 +0000142- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000143 scheme to a new one. See Python/import.c for details.
144
Tim Petersaf8446f2001-12-21 21:36:50 +0000145New platforms
146
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000147- GNU/Hurd is now supported.
148
Tim Petersaf8446f2001-12-21 21:36:50 +0000149Tests
150
151Windows
152
Guido van Rossum181e41a2002-04-06 00:23:25 +0000153- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
154
Tim Peters33187922002-04-04 20:02:04 +0000155- The installer now installs Start menu shortcuts under (the local
156 equivalent of) "All Users" when doing an Admin install.
157
Tim Petersfb05db22002-03-11 00:24:00 +0000158- file.truncate([newsize]) now works on Windows for all newsize values.
159 It used to fail if newsize didn't fit in 32 bits, reflecting a
160 limitation of MS _chsize (which is no longer used).
161
Tim Petersab034fa2002-02-01 11:27:43 +0000162- os.waitpid() is now implemented for Windows, and can be used to block
163 until a specified process exits. This is similar to, but not exactly
164 the same as, os.waitpid() on POSIX systems. If you're waiting for
165 a specific process whose pid was obtained from one of the spawn()
166 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000167 See the docs for details. The docs were changed to clarify that
168 spawn functions return, and waitpid requires, a process handle on
169 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000170
Tim Peters11bd9942002-02-01 00:52:29 +0000171- New tempfile.TemporaryFile implementation for Windows: this doesn't
172 need a TemproraryFileWrapper wrapper anymore, and should be immune
173 to a nasty problem: before 2.3, if you got a temp file on Windows, it
174 got wrapped in an object whose close() method first closed the
175 underlying file, then deleted the file. This usually worked fine.
176 However, the spawn family of functions on Windows create (at a low C
177 level) the same set of open files in the spawned process Q as were
178 open in the spawning process P. If a temp file f was among them, then
179 doing f.close() in P first closed P's C-level file handle on f, but Q's
180 C-level file handle on f remained open, so the attempt in P to delete f
181 blew up with a "Permission denied" error (Windows doesn't allow
182 deleting open files). This was surprising, subtle, and difficult to
183 work around.
184
185- The os module now exports all the symbolic constants usable with the
186 low-level os.open() on Windows: the new constants in 2.3 are
187 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
188 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
189 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
190 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
191 (so specify both if you want both; note that neither is useful unless
192 specified with O_CREAT too).
193
Tim Petersaf8446f2001-12-21 21:36:50 +0000194Mac
195
196
Tim Peters909c0912001-12-14 23:16:18 +0000197What's New in Python 2.2 final?
198Release date: 21-Dec-2001
199===============================
200
201Type/class unification and new-style classes
202
Barry Warsaw52acb492001-12-21 20:04:22 +0000203- pickle.py, cPickle: allow pickling instances of new-style classes
204 with a custom metaclass.
205
Tim Peters909c0912001-12-14 23:16:18 +0000206Core and builtins
207
Barry Warsaw52acb492001-12-21 20:04:22 +0000208- weakref proxy object: when comparing, unwrap both arguments if both
209 are proxies.
210
Tim Peters909c0912001-12-14 23:16:18 +0000211Extension modules
212
Barry Warsaw52acb492001-12-21 20:04:22 +0000213- binascii.b2a_base64(): fix a potential buffer overrun when encoding
214 very short strings.
215
216- cPickle: the obscure "fast" mode was suspected of causing stack
217 overflows on the Mac. Hopefully fixed this by setting the recursion
218 limit much smaller. If the limit is too low (it only affects
219 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
220 when compiling cPickle.c (or in pyconfig.h).
221
Tim Peters909c0912001-12-14 23:16:18 +0000222Library
223
Barry Warsaw52acb492001-12-21 20:04:22 +0000224- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
225 close or delete time).
226
227- rfc822.py: fixed a bug where the address '<>' was converted to None
228 instead of an empty string (also fixes the email.Utils module).
229
230- xmlrpclib.py: version 1.0.0; uses precision for doubles.
231
232- test suite: the pickle and cPickle tests were not executing any code
233 when run from the standard regresssion test.
234
Tim Peters909c0912001-12-14 23:16:18 +0000235Tools/Demos
236
237Build
238
239C API
240
241New platforms
242
243Tests
244
245Windows
246
Barry Warsaw52acb492001-12-21 20:04:22 +0000247- distutils package: fixed broken Windows installers (bdist_wininst).
248
249- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
250 instances are deleted at process exit time.
251
252- socket.py: prevent mysterious warnings when socket instances are
253 deleted at process exit time.
254
255- posixmodule.c: fix a Windows crash with stat() of a filename ending
256 in backslash.
257
Tim Peters909c0912001-12-14 23:16:18 +0000258Mac
259
Barry Warsaw52acb492001-12-21 20:04:22 +0000260- The Carbon toolbox modules have been upgraded to Universal Headers
261 3.4, and experimental CoreGraphics and CarbonEvents modules have
262 been added. All only for framework-enabled MacOSX.
263
Tim Peters909c0912001-12-14 23:16:18 +0000264
Tim Peters6272dfd2001-12-13 19:34:00 +0000265What's New in Python 2.2c1?
266Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000267===========================
268
269Type/class unification and new-style classes
270
Barry Warsaw06557452001-12-14 20:47:12 +0000271- Guido's tutorial introduction to the new type/class features has
272 been extensively updated. See
273
274 http://www.python.org/2.2/descrintro.html
275
276 That remains the primary documentation in this area.
277
Guido van Rossum33bab012001-12-05 22:45:48 +0000278- Fixed a leak: instance variables declared with __slots__ were never
279 deleted!
280
Guido van Rossum4b800852001-12-03 00:54:52 +0000281- The "delete attribute" method of descriptor objects is called
282 __delete__, not __del__. In previous releases, it was mistakenly
283 called __del__, which created an unfortunate overloading condition
284 with finalizers. (The "get attribute" and "set attribute" methods
285 are still called __get__ and __set__, respectively.)
286
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000287- Some subtle issues with the super built-in were fixed:
288
289 (a) When super itself is subclassed, its __get__ method would still
290 return an instance of the base class (i.e., of super).
291
292 (b) super(C, C()).__class__ would return C rather than super. This
293 is confusing. To fix this, I decided to change the semantics of
294 super so that it only applies to code attributes, not to data
295 attributes. After all, overriding data attributes is not
296 supported anyway.
297
298 (c) The __get__ method didn't check whether the argument was an
299 instance of the type used in creation of the super instance.
300
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000301- Previously, hash() of an instance of a subclass of a mutable type
302 (list or dictionary) would return some value, rather than raising
303 TypeError. This has been fixed. Also, directly calling
304 dict.__hash__ and list.__hash__ now raises the same TypeError
305 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000306
Guido van Rossumd331cb52001-12-05 19:46:42 +0000307- New-style objects now support deleting their __dict__. This is for
308 all intents and purposes equivalent to assigning a brand new empty
309 dictionary, but saves space if the object is not used further.
310
Tim Petersb3c9af12001-11-17 00:21:57 +0000311Core and builtins
312
Tim Peters3caca232001-12-06 06:23:26 +0000313- -Qnew now works as documented in PEP 238: when -Qnew is passed on
314 the command line, all occurrences of "/" use true division instead
315 of classic division. See the PEP for details. Note that "all"
316 means all instances in library and 3rd-party modules, as well as in
317 your own code. As the PEP says, -Qnew is intended for use only in
318 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000319 Note that test_coercion.py in the standard Python test suite fails
320 under -Qnew; this is expected, and won't be repaired until true
321 division becomes the default (in the meantime, test_coercion is
322 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000323
Fred Drake6c01e252001-12-14 17:08:12 +0000324- complex() now only allows the first argument to be a string
325 argument, and raises TypeError if either the second arg is a string
326 or if the second arg is specified when the first is a string.
327
Tim Petersb3c9af12001-11-17 00:21:57 +0000328Extension modules
329
Martin v. Löwis560da622001-11-24 09:24:51 +0000330- gc.get_referents was renamed to gc.get_referrers.
331
Tim Petersb3c9af12001-11-17 00:21:57 +0000332Library
333
Tim Peters25059d32001-12-07 20:35:43 +0000334- Functions in the os.spawn() family now release the global interpreter
335 lock around calling the platform spawn. They should always have done
336 this, but did not before 2.2c1. Multithreaded programs calling
337 an os.spawn function with P_WAIT will no longer block all Python threads
338 until the spawned program completes. It's possible that some programs
339 relies on blocking, although more likely by accident than by design.
340
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000341- webbrowser defaults to netscape.exe on OS/2 now.
342
Martin v. Löwis652e1912001-11-25 14:50:56 +0000343- Tix.ResizeHandle exposes detach_widget, hide, and show.
344
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000345- The charset alias windows_1252 has been added.
346
Barry Warsaw06557452001-12-14 20:47:12 +0000347- types.StringTypes is a tuple containing the defined string types;
348 usually this will be (str, unicode), but if Python was compiled
349 without Unicode support it will be just (str,).
350
351- The pulldom and minidom modules were synchronized to PyXML.
352
Tim Petersb3c9af12001-11-17 00:21:57 +0000353Tools/Demos
354
Barry Warsaw06557452001-12-14 20:47:12 +0000355- A new script called Tools/scripts/google.py was added, which fires
356 off a search on Google.
357
Tim Petersb3c9af12001-11-17 00:21:57 +0000358Build
359
Barry Warsaw06557452001-12-14 20:47:12 +0000360- Note that release builds of Python should arrange to define the
361 preprocessor symbol NDEBUG on the command line (or equivalent).
362 In the 2.2 pre-release series we tried to define this by magic in
363 Python.h instead, but it proved to cause problems for extension
364 authors. The Unix, Windows and Mac builds now all define NDEBUG in
365 release builds via cmdline (or equivalent) instead. Ports to
366 other platforms should do likewise.
367
Jack Jansen1999ef42001-12-06 21:47:20 +0000368- It is no longer necessary to use --with-suffix when building on a
369 case-insensitive file system (such as Mac OS X HFS+). In the build
370 directory an extension is used, but not in the installed python.
371
Tim Petersb3c9af12001-11-17 00:21:57 +0000372C API
373
Tim Petersf582b822001-12-11 18:51:08 +0000374- New function PyDict_MergeFromSeq2() exposes the builtin dict
375 constructor's logic for updating a dictionary from an iterable object
376 producing key-value pairs.
377
Tim Peterscffed4b2001-11-29 03:26:37 +0000378- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000379 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000380 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
381 dump core in some bad cases. This has been repaired. As a result,
382 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
383 previously went unchallenged.
384
Tim Petersb3c9af12001-11-17 00:21:57 +0000385New platforms
386
387Tests
388
389Windows
390
391Mac
392
Jack Jansenffa260f2001-12-06 21:14:00 +0000393- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
394 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000395
Barry Warsaw06557452001-12-14 20:47:12 +0000396- Changed logic for finding python home in Mac OS X framework Pythons.
397 Now sys.executable points to the executable again, in stead of to
398 the shared library. The latter is used only for locating the python
399 home.
400
401
Tim Peters84362bc2001-10-19 17:55:30 +0000402What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000403Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000404===========================
405
406Type/class unification and new-style classes
407
Guido van Rossum3d27df02001-11-15 20:27:54 +0000408- Multiple inheritance mixing new-style and classic classes in the
409 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000410
411 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000412 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000413
414 The MRO (method resolution order) for each base class is respected
415 according to its kind, but the MRO for the derived class is computed
416 using new-style MRO rules if any base clase is a new-style class.
417 This needs to be documented.
418
Tim Petersa427a2b2001-10-29 22:25:45 +0000419- The new builtin dictionary() constructor, and dictionary type, have
420 been renamed to dict. This reflects a decade of common usage.
421
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000422- dict() now accepts an iterable object producing 2-sequences. For
423 example, dict(d.items()) == d for any dictionary d. The argument,
424 and the elements of the argument, can be any iterable objects.
425
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000426- New-style classes can now have a __del__ method, which is called
427 when the instance is deleted (just like for classic classes).
428
Guido van Rossum12d955c2001-10-26 14:56:06 +0000429- Assignment to object.__dict__ is now possible, for objects that are
430 instances of new-style classes that have a __dict__ (unless the base
431 class forbids it).
432
Guido van Rossumc8e56452001-10-22 00:43:43 +0000433- Methods of built-in types now properly check for keyword arguments
434 (formerly these were silently ignored). The only built-in methods
435 that take keyword arguments are __call__, __init__ and __new__.
436
Guido van Rossum86443212001-10-27 22:28:54 +0000437- The socket function has been converted to a type; see below.
438
Tim Peters84362bc2001-10-19 17:55:30 +0000439Core and builtins
440
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000441- Assignment to __debug__ raises SyntaxError at compile-time. This
442 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000443 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000444
Guido van Rossum12d955c2001-10-26 14:56:06 +0000445- Clarified the error messages for unsupported operands to an operator
446 (like 1 + '').
447
Tim Peters84362bc2001-10-19 17:55:30 +0000448Extension modules
449
Tim Peters5ebfd362001-11-13 23:11:19 +0000450- mmap has a new keyword argument, "access", allowing a uniform way for
451 both Windows and Unix users to create read-only, write-through and
452 copy-on-write memory mappings. This was previously possible only on
453 Unix. A new keyword argument was required to support this in a
454 uniform way because the mmap() signuatures had diverged across
455 platforms. Thanks to Jay T Miller for repairing this!
456
Tim Peters169ded02001-11-03 19:57:21 +0000457- By default, the gc.garbage list now contains only those instances in
458 unreachable cycles that have __del__ methods; in 2.1 it contained all
459 instances in unreachable cycles. "Instances" here has been generalized
460 to include instances of both new-style and old-style classes.
461
Guido van Rossum12d955c2001-10-26 14:56:06 +0000462- The socket module defines a new method for socket objects,
463 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000464 send() until all data has been sent. Also, the socket function has
465 been converted to a subclassable type, like list and tuple (etc.)
466 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000467
468- Various bugfixes to the curses module. There is now a test suite
469 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000470
Guido van Rossum692adf12001-10-30 03:03:03 +0000471- binascii.b2a_base64 no longer places an arbitrary restriction of 57
472 bytes on its input.
473
Tim Peters84362bc2001-10-19 17:55:30 +0000474Library
475
Tim Peters5ebfd362001-11-13 23:11:19 +0000476- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000477 convenience function.
478
Tim Peters75335872001-11-03 19:35:43 +0000479- Symbolic group names in regular expressions must be unique. For
480 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
481 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000482 Python 2.2 detects this error at regexp compilation time;
483 previously, the error went undetected, and results were
484 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
485 pattern.subn() methods have been rewritten in C. Also, an
486 experimental function/method finditer() has been added, which works
487 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000488
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000489- Tix exposes more commands through the classes DirSelectBox,
490 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
491 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
492 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
493
Tim Peters98791af2001-10-23 01:59:54 +0000494- Traceback objects are now scanned by cyclic garbage collection, so
495 cycles created by casual use of sys.exc_info() no longer cause
496 permanent memory leaks (provided garbage collection is enabled).
497
Guido van Rossum49192142001-10-24 20:51:44 +0000498- os.extsep -- a new variable needed by the RISCOS support. It is the
499 separator used by extensions, and is '.' on all platforms except
500 RISCOS, where it is '/'. There is no need to use this variable
501 unless you have a masochistic desire to port your code to RISCOS.
502
Barry Warsaw012852b2001-11-16 16:17:27 +0000503- mimetypes.py has optional support for non-standard, but commonly
504 found types. guess_type() and guess_extension() now accept an
505 optional `strict' flag, defaulting to true, which controls whether
506 recognize non-standard types or not. A few non-standard types we
507 know about have been added. Also, when run as a script, there are
508 new -l and -e options.
509
510- statcache is now deprecated.
511
512- email.Utils.formatdate() now produces the preferred RFC 2822 style
513 dates with numeric timezones (it used to produce obsolete dates
514 hard coded to "GMT" timezone). An optional `localtime' flag is
515 added to produce dates in the local timezone, with daylight savings
516 time properly taken into account.
517
518- In pickle and cPickle, instead of masking errors in load() by
519 transforming them into SystemError, we let the original exception
520 propagate out. Also, implement support for __safe_for_unpickling__
521 in pickle, as it already was supported in cPickle.
522
Tim Peters84362bc2001-10-19 17:55:30 +0000523Tools/Demos
524
525Build
526
Barry Warsaw012852b2001-11-16 16:17:27 +0000527- The dbm module is built using libdb1 if available. The bsddb module
528 is built with libdb3 if available.
529
530- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
531
Tim Peters84362bc2001-10-19 17:55:30 +0000532C API
533
Tim Peters1fc240e2001-10-26 05:06:50 +0000534- New function PySequence_Fast_GET_SIZE() returns the size of a non-
535 NULL result from PySequence_Fast(), more quickly than calling
536 PySequence_Size().
537
Barry Warsaw012852b2001-11-16 16:17:27 +0000538- New argument unpacking function PyArg_UnpackTuple() added.
539
540- New functions PyObject_CallFunctionObjArgs() and
541 PyObject_CallMethodObjArgs() have been added to make it more
542 convenient and efficient to call functions and methods from C.
543
544- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
545 possible that this will propagate errors it didn't before.
546
547- New function PyObject_CheckReadBuffer(), which returns true if its
548 argument supports the single-segment readable buffer interface.
549
Tim Peters84362bc2001-10-19 17:55:30 +0000550New platforms
551
Guido van Rossum86443212001-10-27 22:28:54 +0000552- We've finally confirmed that this release builds on HP-UX 11.00,
553 *with* threads, and passes the test suite.
554
Tim Peters7a33d8b2001-11-05 02:51:07 +0000555- Thanks to a series of patches from Michael Muller, Python may build
556 again under OS/2 Visual Age C++.
557
Guido van Rossum49192142001-10-24 20:51:44 +0000558- Updated RISCOS port by Dietmar Schwertberger.
559
Tim Peters84362bc2001-10-19 17:55:30 +0000560Tests
561
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000562- Added a test script for the curses module. It isn't run automatically;
563 regrtest.py must be run with '-u curses' to enable it.
564
Tim Peters84362bc2001-10-19 17:55:30 +0000565Windows
566
Barry Warsaw012852b2001-11-16 16:17:27 +0000567Mac
568
569- PythonScript has been moved to unsupported and is slated to be
570 removed completely in the next release.
571
572- It should now be possible to build applets that work on both OS9 and
573 OSX.
574
575- The core is now linked with CoreServices not Carbon; as a side
576 result, default 8bit encoding on OSX is now ASCII.
577
578- Python should now build on OSX 10.1.1
579
Tim Peters84362bc2001-10-19 17:55:30 +0000580
Tim Petersabf925f2001-09-28 21:53:42 +0000581What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000582Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000583===========================
584
585Type/class unification and new-style classes
586
Guido van Rossum687ae002001-10-15 22:03:32 +0000587- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000588 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000589 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000590 remains: the __dict__ of a new-style class is a read-only proxy; you
591 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000592 __defined__ attribute of new-style types no longer exists, for lack
593 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000594 future a __cache__ may be resurrected with a similar function, if I
595 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000596
Tim Peters1c9ca872001-10-04 06:43:12 +0000597- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
598 always returned None, even when there was a class docstring).
599
600- doctest now finds and runs docstrings attached to new-style classes,
601 class methods, static methods, and properties.
602
Guido van Rossum9074ef62001-10-16 21:34:49 +0000603Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000604
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000605- A very subtle syntactical pitfall in list comprehensions was fixed.
606 For example: [a+b for a in 'abc', for b in 'def']. The comma in
607 this example is a mistake. Previously, this would silently let 'a'
608 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
609 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
610 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
611 Note that [a for a in <singleton>] is a convoluted way to say
612 [<singleton>] anyway, so it's not like any expressiveness is lost.
613
Guido van Rossum9074ef62001-10-16 21:34:49 +0000614- getattr(obj, name, default) now only catches AttributeError, as
615 documented, rather than returning the default value for all
616 exceptions (which could mask bugs in a __getattr__ hook, for
617 example).
618
Fred Drakecb7a6b52001-10-22 18:41:51 +0000619- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000620 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000621 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000622 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000623
Guido van Rossum1c486092001-10-19 02:05:35 +0000624- unicode(obj) now behaves more like str(obj), accepting arbitrary
625 objects, and calling a __unicode__ method if it exists.
626 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000627 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000628
Barry Warsawf6fb1712001-10-19 05:35:40 +0000629- isinstance() now allows any object as the first argument and a
630 class, a type or something with a __bases__ tuple attribute for the
631 second argument. The second argument may also be a tuple of a
632 class, type, or something with __bases__, in which case isinstance()
633 will return true if the first argument is an instance of any of the
634 things contained in the second argument tuple. E.g.
635
636 isinstance(x, (A, B))
637
638 returns true if x is an instance of A or B.
639
Guido van Rossum9074ef62001-10-16 21:34:49 +0000640Extension modules
641
642- thread.start_new_thread() now returns the thread ID (previously None).
643
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000644- binascii has now two quopri support functions, a2b_qp and b2a_qp.
645
Guido van Rossumc524d952001-10-19 01:31:59 +0000646- readline now supports setting the startup_hook and the
647 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000648
Guido van Rossumc524d952001-10-19 01:31:59 +0000649- os and posix supports chroot(), setgroups() and unsetenv() where
650 available. The stat(), fstat(), statvfs() and fstatvfs() functions
651 now return "pseudo-sequences" -- the various fields can now be
652 accessed as attributes (e.g. os.stat("/").st_mtime) but for
653 backwards compatibility they also behave as a fixed-length sequence.
654 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000655 attributes.
656
657- time: localtime(), gmtime() and strptime() now return a
658 pseudo-sequence similar to the os.stat() return value, with
659 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000660
Guido van Rossum9074ef62001-10-16 21:34:49 +0000661- Decompression objects in the zlib module now accept an optional
662 second parameter to decompress() that specifies the maximum amount
663 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000664
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000665- optional SSL support in the socket module now exports OpenSSL
666 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
667 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000668 automatically seed its PRNG. Also, the keyfile and certfile
669 arguments to socket.ssl() are now optional.
670
671- posixmodule (and by extension, the os module on POSIX platforms) now
672 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000673
Guido van Rossum9074ef62001-10-16 21:34:49 +0000674Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000675
Tim Peters7402f792001-10-02 03:53:41 +0000676- doctest now excludes functions and classes not defined by the module
677 being tested, thanks to Tim Hochberg.
678
Fred Drakecb7a6b52001-10-22 18:41:51 +0000679- HotShot, a new profiler implemented using a C-based callback, has
680 been added. This substantially reduces the overhead of profiling,
681 but it is still quite preliminary. Support modules and
682 documentation will be added in upcoming releases (before 2.2 final).
683
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000684- profile now produces correct output in situations where an exception
685 raised in Python is cleared by C code (e.g. hasattr()). This used
686 to cause wrong output, including spurious claims of recursive
687 functions and attribution of time spent to the wrong function.
688
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000689 The code and documentation for the derived OldProfile and HotProfile
690 profiling classes was removed. The code hasn't worked for years (if
691 you tried to use them, they raised exceptions). OldProfile
692 intended to reproduce the behavior of the profiler Python used more
693 than 7 years ago, and isn't interesting anymore. HotProfile intended
694 to provide a faster profiler (but producing less information), and
695 that's a worthy goal we intend to meet via a different approach (but
696 without losing information).
697
Tim Peterscce092d2001-10-09 05:31:56 +0000698- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000699 a much better system-specific calibration constant. The constant can
700 now be specified in an instance constructor, or as a Profile class or
701 instance variable, instead of by editing profile.py's source code.
702 Calibration must still be done manually (see the docs for the profile
703 module).
704
705 Note that Profile.calibrate() must be overriden by subclasses.
706 Improving the accuracy required exploiting detailed knowledge of
707 profiler internals; the earlier method abstracted away the details
708 and measured a simplified model instead, but consequently computed
709 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000710
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000711- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000712 which indicates whether output is intended for the header 'Q'
713 encoding.
714
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000715- The SocketServer.ThreadingMixIn class now closes the request after
716 finish_request() returns. (Not when it errors out though.)
717
Barry Warsawf6fb1712001-10-19 05:35:40 +0000718- The nntplib module's NNTP.body() method has grown a `file' argument
719 to allow saving the message body to a file.
720
721- The email package has added a class email.Parser.HeaderParser which
722 only parses headers and does not recurse into the message's body.
723 Also, the module/class MIMEAudio has been added for representing
724 audio data (contributed by Anthony Baxter).
725
726- ftplib should be able to handle files > 2GB.
727
728- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
729 ON, and OFF.
730
Fred Drakecb7a6b52001-10-22 18:41:51 +0000731- xml.dom.minidom NodeList objects now support the length attribute
732 and item() method as required by the DOM specifications.
733
Guido van Rossumed554f62001-10-02 23:15:37 +0000734Tools/Demos
735
736- Demo/dns was removed. It no longer serves any purpose; a package
737 derived from it is now maintained by Anthony Baxter, see
738 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000739
Barry Warsawf6fb1712001-10-19 05:35:40 +0000740- The freeze tool has been made more robust, and two new options have
741 been added: -X and -E.
742
Tim Petersabf925f2001-09-28 21:53:42 +0000743Build
744
Barry Warsawf6fb1712001-10-19 05:35:40 +0000745- configure will use CXX in LINKCC if CXX is used to build main() and
746 the system requires to link a C++ main using the C++ compiler.
747
Tim Petersabf925f2001-09-28 21:53:42 +0000748C API
749
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000750- The documentation for the tp_compare slot is updated to require that
751 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
752 not correct. This is not yet enforced but will be enforced in
753 Python 2.3; even later, we may use -2 to indicate errors and +2 for
754 "NotImplemented". Right now, -1 should be used for an error return.
755
Tim Petersd38b1c72001-09-30 05:09:37 +0000756- PyLong_AsLongLong() now accepts int (as well as long) arguments.
757 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
758 as long) arguments.
759
Guido van Rossum3c288632001-10-16 21:13:49 +0000760- PyThread_start_new_thread() now returns a long int giving the thread
761 ID, if one can be calculated; it returns -1 for error, 0 if no
762 thread ID is calculated (this is an incompatible change, but only
763 the thread module used this API). This code has only really been
764 tested on Linux and Windows; other platforms please beware (and
765 report any bugs or strange behavior).
766
Guido van Rossum1c486092001-10-19 02:05:35 +0000767- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
768 input.
769
Tim Petersabf925f2001-09-28 21:53:42 +0000770New platforms
771
772Tests
773
774Windows
775
Tim Peters04cf1d32001-10-09 22:39:40 +0000776- Installer: If you install IDLE, and don't disable file-extension
777 registration, a new "Edit with IDLE" context (right-click) menu entry
778 is created for .py and .pyw files.
779
Tim Peters1ce3cf72001-10-01 17:58:40 +0000780- The signal module now supports SIGBREAK on Windows, thanks to Steven
781 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
782 action remains to call Win32 ExitProcess(). This can be changed via
783 signal.signal(). For example:
784
785 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
786 # (SIGINT) behavior.
787 import signal
788 signal.signal(signal.SIGBREAK,
789 signal.default_int_handler)
790
791 try:
792 while 1:
793 pass
794 except KeyboardInterrupt:
795 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
796 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
797 # program without the possibility for any Python-level cleanup).
798 print "Clean exit"
799
Tim Petersabf925f2001-09-28 21:53:42 +0000800
Tim Petersb07352e2001-09-08 01:25:47 +0000801What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000802Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000803===========================
804
Guido van Rossum808eea72001-09-25 04:15:41 +0000805Type/class unification and new-style classes
806
807- pydoc and inspect are now aware of new-style classes;
808 e.g. help(list) at the interactive prompt now shows proper
809 documentation for all operations on list objects.
810
811- Applications using Jim Fulton's ExtensionClass module can now safely
812 be used with Python 2.2. In particular, Zope 2.4.1 now works with
813 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
814 examples also work again. It is hoped that Gtk and Boost also work
815 with 2.2a4 and beyond. (If you can confirm this, please write
816 webmaster@python.org; if there are still problems, please open a bug
817 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000818
Tim Peters66c1a522001-09-24 21:17:50 +0000819- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
820 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
821 in the constructed property object. fget, fset and fdel weren't
822 discoverable from Python in 2.2a3. __doc__ is new, and allows to
823 associate a docstring with a property.
824
Guido van Rossum808eea72001-09-25 04:15:41 +0000825- Comparison overloading is now more completely implemented. For
826 example, a str subclass instance can properly be compared to a str
827 instance, and it can properly overload comparison. Ditto for most
828 other built-in object types.
829
830- The repr() of new-style classes has changed; instead of <type
831 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
832 *except* for built-in types, which are still rendered as <type
833 'Foo'> (to avoid upsetting existing code that might parse or
834 otherwise rely on repr() of certain type objects).
835
836- The repr() of new-style objects is now always <Foo object at XXX>;
837 previously, it was sometimes <Foo instance at XXX>.
838
839- For new-style classes, what was previously called __getattr__ is now
840 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000841 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000842 one in classic classes is defined which is called only if regular
843 attribute access raises AttributeError; to catch *all* attribute
844 access, you can use __getattribute__ (for new-style classes). If
845 both are defined, __getattribute__ is called first, and if it raises
846 AttributeError, __getattr__ is called.
847
848- The __class__ attribute of new-style objects can be assigned to.
849 The new class must have the same C-level object layout as the old
850 class.
851
852- The builtin file type can be subclassed now. In the usual pattern,
853 "file" is the name of the builtin type, and file() is a new builtin
854 constructor, with the same signature as the builtin open() function.
855 file() is now the preferred way to open a file.
856
857- Previously, __new__ would only see sequential arguments passed to
858 the type in a constructor call; __init__ would see both sequential
859 and keyword arguments. This made no sense whatsoever any more, so
860 now both __new__ and __init__ see all arguments.
861
862- Previously, hash() applied to an instance of a subclass of str or
863 unicode always returned 0. This has been repaired.
864
865- Previously, an operation on an instance of a subclass of an
866 immutable type (int, long, float, complex, tuple, str, unicode),
867 where the subtype didn't override the operation (and so the
868 operation was handled by the builtin type), could return that
869 instance instead a value of the base type. For example, if s was of
870 a str sublass type, s[:] returned s as-is. Now it returns a str
871 with the same value as s.
872
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000873- Provisional support for pickling new-style objects has been added.
874
Guido van Rossum808eea72001-09-25 04:15:41 +0000875Core
876
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000877- file.writelines() now accepts any iterable object producing strings.
878
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000879- PyUnicode_FromEncodedObject() now works very much like
880 PyObject_Str(obj) in that it tries to use __str__/tp_str
881 on the object if the object is not a string or buffer. This
882 makes unicode() behave like str() when applied to non-string/buffer
883 objects.
884
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000885- PyFile_WriteObject now passes Unicode objects to the file's write
886 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000887 of a print statement must support Unicode objects, i.e. they must
888 at least convert them into ASCII strings.
889
Guido van Rossum624c8af2001-09-18 15:21:04 +0000890- Thread scheduling on Solaris should be improved; it is no longer
891 necessary to insert a small sleep at the start of a thread in order
892 to let other runnable threads be scheduled.
893
Tim Petersb07352e2001-09-08 01:25:47 +0000894Library
895
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000896- StringIO.StringIO instances and cStringIO.StringIO instances support
897 read character buffer compatible objects for their .write() methods.
898 These objects are converted to strings and then handled as such
899 by the instances.
900
Barry Warsaw2f600732001-09-24 04:28:10 +0000901- The "email" package has been added. This is basically a port of the
902 mimelib package <http://sf.net/projects/mimelib> with API changes
903 and some implementations updated to use iterators and generators.
904
Tim Peters8a9c2842001-09-22 21:30:22 +0000905- difflib.ndiff() and difflib.Differ.compare() are generators now. This
906 restores the ability of Tools/scripts/ndiff.py to start producing output
907 before the entire comparison is complete.
908
Barry Warsaw58b072d2001-09-22 04:44:21 +0000909- StringIO.StringIO instances and cStringIO.StringIO instances support
910 iteration just like file objects (i.e. their .readline() method is
911 called for each iteration until it returns an empty string).
912
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000913- The codecs module has grown four new helper APIs to access
914 builtin codecs: getencoder(), getdecoder(), getreader(),
915 getwriter().
916
Guido van Rossum624c8af2001-09-18 15:21:04 +0000917- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
918 simplifies writing XML RPC servers.
919
Barry Warsaw647d5e82001-09-28 17:01:02 +0000920- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000921 after interpretation of symbolic links. On non-Unix systems, this
922 is an alias for os.path.abspath().
923
Tim Peters16a77ad2001-09-08 04:00:12 +0000924- operator.indexOf() (PySequence_Index() in the C API) now works with any
925 iterable object.
926
Guido van Rossum624c8af2001-09-18 15:21:04 +0000927- smtplib now supports various authentication and security features of
928 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000929
Guido van Rossum624c8af2001-09-18 15:21:04 +0000930- hmac: a new module implementing keyed hashing for message
931 authentication.
932
933- mimetypes now recognizes more extensions and file types. At the
934 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000935
Guido van Rossum624c8af2001-09-18 15:21:04 +0000936- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000937 Python 2.2 bytecode generation. It has also been promoted from a
938 Tool to a standard library package. (Tools/compiler still exists as
939 a sample driver.)
940
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000941Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000942
Tim Petersb07352e2001-09-08 01:25:47 +0000943Build
944
Guido van Rossum624c8af2001-09-18 15:21:04 +0000945- Large file support (LFS) is now automatic when the platform supports
946 it; no more manual configuration tweaks are needed. On Linux, at
947 least, it's possible to have a system whose C library supports large
948 files but whose kernel doesn't; in this case, large file support is
949 still enabled but doesn't do you any good unless you upgrade your
950 kernel or share your Python executable with another system whose
951 kernel has large file support.
952
953- The configure script now supplies plausible defaults in a
954 cross-compilation environment. This doesn't mean that the supplied
955 values are always correct, or that cross-compilation now works
956 flawlessly -- but it's a first step (and it shuts up most of
957 autoconf's warnings about AC_TRY_RUN).
958
959- The Unix build is now a bit less chatty, courtesy of the parser
960 generator. The build is completely silent (except for errors) when
961 using "make -s", thanks to a -q option to setup.py.
962
Tim Petersb07352e2001-09-08 01:25:47 +0000963C API
964
Guido van Rossum624c8af2001-09-18 15:21:04 +0000965- The "structmember" API now supports some new flag bits to deny read
966 and/or write access to attributes in restricted execution mode.
967
Tim Petersb07352e2001-09-08 01:25:47 +0000968New platforms
969
Guido van Rossum624c8af2001-09-18 15:21:04 +0000970- Compaq's iPAQ handheld, running the "familiar" Linux distribution
971 (http://familiar.handhelds.org).
972
Tim Petersb07352e2001-09-08 01:25:47 +0000973Tests
974
Tim Peters8a9c2842001-09-22 21:30:22 +0000975- The "classic" standard tests, which work by comparing stdout to
976 an expected-output file under Lib/test/output/, no longer stop at
977 the first mismatch. Instead the test is run to completion, and a
978 variant of ndiff-style comparison is used to report all differences.
979 This is much easier to understand than the previous style of reporting.
980
981- The unittest-based standard tests now use regrtest's test_main()
982 convention, instead of running as a side-effect of merely being
983 imported. This allows these tests to be run in more natural and
984 flexible ways as unittests, outside the regrtest framework.
985
986- regrtest.py is much better integrated with unittest and doctest now,
987 especially in regard to reporting errors.
988
Tim Petersb07352e2001-09-08 01:25:47 +0000989Windows
990
Guido van Rossum624c8af2001-09-18 15:21:04 +0000991- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000992 that support it (NTFS under Windows 2000). See "What's New in
993 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000994
Tim Petersb07352e2001-09-08 01:25:47 +0000995
Tim Petersedc99312001-08-22 21:36:50 +0000996What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000997Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000998===========================
999
1000Core
1001
Tim Peters9fffa3e2001-09-04 05:14:19 +00001002- Conversion of long to float now raises OverflowError if the long is too
1003 big to represent as a C double.
1004
Tim Peters32f453e2001-09-03 08:35:41 +00001005- The 3-argument builtin pow() no longer allows a third non-None argument
1006 if either of the first two arguments is a float, or if both are of
1007 integer types and the second argument is negative (in which latter case
1008 the arguments are converted to float, so this is really the same
1009 restriction).
1010
Tim Peters5d2b77c2001-09-03 05:47:38 +00001011- The builtin dir() now returns more information, and sometimes much
1012 more, generally naming all attributes of an object, and all attributes
1013 reachable from the object via its class, and from its class's base
1014 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1015 an empty list. In 2.2a3,
1016
1017 >>> dir([])
1018 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1019 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1020 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1021 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1022 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1023 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1024 'reverse', 'sort']
1025
1026 dir(module) continues to return only the module's attributes, though.
1027
Tim Petersbdee63f2001-09-02 03:40:59 +00001028- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001029 than raising OverflowError. This is a partial implementation of PEP
1030 237. You can use -Wdefault::OverflowWarning to enable a warning for
1031 this situation, and -Werror::OverflowWarning to revert to the old
1032 OverflowError exception.
1033
Guido van Rossum61c345f2001-09-04 03:26:15 +00001034- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001035 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001036 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1037 -Qold, meaning the / operator has its classic meaning and no
1038 warnings are issued. Using -Qwarn issues a run-time warning about
1039 all uses of classic division for int and long arguments; -Qwarnall
1040 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001041 (for use with fixdiv.py).
1042 [Note: the remainder of this paragraph (preserved below) became
1043 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1044 <obsolete>
1045 Using -Qnew is questionable; it turns on new division by default, but
1046 only in the __main__ module. You can usefully combine -Qwarn or
1047 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1048 warns about classic division everywhere else.
1049 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001050
Tim Petersbdee63f2001-09-02 03:40:59 +00001051- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001052 long, float, str, unicode, and tuple. (The types complex, list and
1053 dictionary can also be subclassed; this was introduced earlier.)
1054 Note that restrictions apply when subclassing immutable built-in
1055 types: you can only affect the value of the instance by overloading
1056 __new__. You can add mutable attributes, and the subclass instances
1057 will have a __dict__ attribute, but you cannot change the "value"
1058 (as implemented by the base class) of an immutable subclass instance
1059 once it is created.
1060
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001061- The dictionary constructor now takes an optional argument, a
1062 mapping-like object, and initializes the dictionary from its
1063 (key, value) pairs.
1064
Tim Petersbdee63f2001-09-02 03:40:59 +00001065- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001066 "cooperative super calls" in a multiple inheritance setting. For an
1067 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1068
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001069- A new built-in type, property, has been added. This enables the
1070 creation of "properties". These are attributes implemented by
1071 getter and setter functions (or only one of these for read-only or
1072 write-only attributes), without the need to override __getattr__.
1073 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001074
Tim Petersbdee63f2001-09-02 03:40:59 +00001075- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001076 liberalized, to allow leading zeroes. Examples of literals now
1077 legal that were SyntaxErrors before:
1078
1079 00.0 0e3 0100j 07.5 00000000000000000008.
1080
Tim Petersbdee63f2001-09-02 03:40:59 +00001081- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001082 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1083
Tim Petersedc99312001-08-22 21:36:50 +00001084Library
1085
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001086- telnetlib includes symbolic names for the options, and support for
1087 setting an option negotiation callback.
1088
Tim Petersa40c7932001-09-05 22:36:56 +00001089- The new C standard no longer requires that math libraries set errno to
1090 ERANGE on overflow. For platform libraries that exploit this new
1091 freedom, Python's overflow-checking was wholly broken. A new overflow-
1092 checking scheme attempts to repair that, but may not be reliable on all
1093 platforms (C doesn't seem to provide anything both useful and portable
1094 in this area anymore).
1095
Martin v. Löwis44f86962001-09-05 13:44:54 +00001096- Asynchronous timeout actions are available through the new class
1097 threading.Timer.
1098
Tim Peters78526162001-09-05 00:53:45 +00001099- math.log and math.log10 now return sensible results for even huge
1100 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1101
Tim Petersbdee63f2001-09-02 03:40:59 +00001102- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001103 currently held. See the docs for the imp module.
1104
Tim Petersbdee63f2001-09-02 03:40:59 +00001105- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001106 dumps containing ints written on platforms where Python ints are 8 bytes.
1107 When read on a box where Python ints are 4 bytes, such values are
1108 converted to Python longs.
1109
Tim Petersbdee63f2001-09-02 03:40:59 +00001110- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001111 code objects is no longer allowed. This plugs a security hole.
1112
Steve Purcell6091cd62001-09-06 16:05:17 +00001113- unittest.TestResult instances no longer store references to tracebacks
1114 generated by test failures. This prevents unexpected dangling references
1115 to objects that should be garbage collected between tests.
1116
Tim Petersedc99312001-08-22 21:36:50 +00001117Tools
1118
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001119- Tools/scripts/fixdiv.py has been added which can be used to fix
1120 division operators as per PEP 238.
1121
Tim Petersedc99312001-08-22 21:36:50 +00001122Build
1123
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001124- If you are an adventurous person using Mac OS X you may want to look at
1125 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1126 application, which can be used for experimenting with Carbon or Cocoa.
1127 Discussion of this on pythonmac-sig, please.
1128
Tim Peters7eea37e2001-09-04 22:08:56 +00001129C API
1130
1131- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001132
Tim Peters9fffa3e2001-09-04 05:14:19 +00001133- Note that PyLong_AsDouble can fail! This has always been true, but no
1134 callers checked for it. It's more likely to fail now, because overflow
1135 errors are properly detected now. The proper way to check:
1136
1137 double x = PyLong_AsDouble(some_long_object);
1138 if (x == -1.0 && PyErr_Occurred()) {
1139 /* The conversion failed. */
1140 }
1141
Tim Petersbdee63f2001-09-02 03:40:59 +00001142- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001143 compile but will not participate in GC. To upgrade an extension
1144 module:
1145
1146 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001147
Neil Schemenauer4042c692001-08-30 15:38:01 +00001148 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1149 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001150
Neil Schemenauer4042c692001-08-30 15:38:01 +00001151 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1152 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001153
Neil Schemenauer4042c692001-08-30 15:38:01 +00001154 - remove PyGC_HEAD_SIZE from object size calculations
1155
1156 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1157
Tim Petersbdee63f2001-09-02 03:40:59 +00001158- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001159 These can be used safely to construct string objects from a
1160 sprintf-style format string (similar to the format string supported
1161 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001162
Tim Petersedc99312001-08-22 21:36:50 +00001163New platforms
1164
Tim Petersb7da0902001-09-02 23:01:43 +00001165- Stephen Hansen contributed patches sufficient to get a clean compile
1166 under Borland C (Windows), but he reports problems running it and ran
1167 out of time to complete the port. Volunteers? Expect a MemoryError
1168 when importing the types module; this is probably shallow, and
1169 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001170
Tim Petersedc99312001-08-22 21:36:50 +00001171Tests
1172
1173Windows
1174
Tim Peters6e13a562001-09-06 00:32:15 +00001175- Large file support is now enabled on Win32 platforms as well as on
1176 Win64. This means that, for example, you can use f.tell() and f.seek()
1177 to manipulate files larger than 2 gigabytes (provided you have enough
1178 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001179 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1180 filesize limit, and large file support makes no difference there.
1181 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1182 NTFS has no practical limit on file size, and files of any size can be
1183 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001184
Tim Petersbdee63f2001-09-02 03:40:59 +00001185- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001186 points to command.com (patch from Brian Quinlan).
1187
Tim Petersedc99312001-08-22 21:36:50 +00001188
Tim Peters20f51a72001-07-21 02:31:40 +00001189What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001190Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001191===========================
1192
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001193Build
1194
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001195- Tim Peters developed a brand new Windows installer using Wise 8.1,
1196 generously donated to us by Wise Solutions.
1197
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001198- configure supports a new option --enable-unicode, with the values
1199 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1200 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001201
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001202- A new configure option --enable-framework builds a Mac OS X framework,
1203 which "make frameworkinstall" will install. This provides a starting
1204 point for more mac-like functionality, join pythonmac-sig@python.org
1205 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001206
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001207- The NeXT platform is no longer supported.
1208
1209- The `new' module is now statically linked.
1210
Tim Peters0afb6092001-08-15 06:06:44 +00001211Tools
1212
1213- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001214 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001215 the module docstring for details.
1216
Tim Peters20f51a72001-07-21 02:31:40 +00001217Tests
1218
Tim Peters5e824c32001-08-12 22:25:01 +00001219- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001220 platforms, allowing to give clearer test result output. regrtest
1221 also has optional --use/-u switch to run normally disabled tests
1222 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001223
Tim Peters20f51a72001-07-21 02:31:40 +00001224- Several new tests in the standard test suite, with special thanks to
1225 Nick Mathewson.
1226
1227Core
1228
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001229- The floor division operator // has been added as outlined in PEP
1230 238. The / operator still provides classic division (and will until
1231 Python 3.0) unless "from __future__ import division" is included, in
1232 which case the / operator will provide true division. The operator
1233 module provides truediv() and floordiv() functions. Augmented
1234 assignment variants are included, as are the equivalent overloadable
1235 methods and C API methods. See the PEP for a full discussion:
1236 <http://python.sf.net/peps/pep-0238.html>
1237
Tim Peters6cd6a822001-08-17 22:11:27 +00001238- Future statements are now effective in simulated interactive shells
1239 (like IDLE). This should "just work" by magic, but read Michael
1240 Hudson's "Future statements in simulated shells" PEP 264 for full
1241 details: <http://python.sf.net/peps/pep-0264.html>.
1242
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001243- The type/class unification (PEP 252-253) was integrated into the
1244 trunk and is not so tentative any more (the exact specification of
1245 some features is still tentative). A lot of work has done on fixing
1246 bugs and adding robustness and features (performance still has to
1247 come a long way).
1248
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001249- Warnings about a mismatch in the Python API during extension import
1250 now use the Python warning framework (which makes it possible to
1251 write filters for these warnings).
1252
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001253- A function's __dict__ (aka func_dict) will now always be a
1254 dictionary. It used to be possible to delete it or set it to None,
1255 but now both actions raise TypeErrors. It is still legal to set it
1256 to a dictionary object. Getting func.__dict__ before any attributes
1257 have been assigned now returns an empty dictionary instead of None.
1258
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001259- A new command line option, -E, was added which disables the use of
1260 all environment variables, or at least those that are specifically
1261 significant to Python. Usually those have a name starting with
1262 "PYTHON". This was used to fix a problem where the tests fail if
1263 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1264 older distribution.
1265
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001266Library
1267
Tim Peters5e824c32001-08-12 22:25:01 +00001268- New class Differ and new functions ndiff() and restore() in difflib.py.
1269 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001270 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001271
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001272- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1273 value using the minimal quoting required for the value; more
1274 reliable than using xml.sax.saxutils.escape() for attribute values.
1275
1276- Readline completion support for cmd.Cmd was added.
1277
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001278- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1279
1280- Added function threading.BoundedSemaphore()
1281
1282- Added Ka-Ping Yee's cgitb.py module.
1283
1284- The `new' module now exposes the CO_xxx flags.
1285
Martin v. Löwis560da622001-11-24 09:24:51 +00001286- The gc module offers the get_referents function.
1287
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001288New platforms
1289
1290C API
1291
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001292- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1293 which provide a cross-platform implementations for the
1294 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1295 the standard sprintf() and vsprintf() C lib APIs, these versions
1296 apply bounds checking on the used buffer which enhances protection
1297 against buffer overruns.
1298
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001299- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001300 and extensions using different Unicode widths is rendered next to
1301 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001302 will result in an ImportError. Unicode extensions writers must make
1303 sure to check the Unicode width compatibility in their extensions by
1304 using at least one of the mangled Unicode APIs in the extension.
1305
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001306- Two new flags METH_NOARGS and METH_O are available in method definition
1307 tables to simplify implementation of methods with no arguments and a
1308 single untyped argument. Calling such methods is more efficient than
1309 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1310 deprecated.
1311
Tim Petersc1731372001-08-04 08:12:36 +00001312Windows
1313
1314- "import module" now compiles module.pyw if it exists and nothing else
1315 relevant is found.
1316
Tim Peters20f51a72001-07-21 02:31:40 +00001317
Guido van Rossum55a78992001-07-17 17:22:32 +00001318What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001319Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001320===========================
1321
1322Core
Tim Petersa814db52001-05-14 07:05:58 +00001323
Tim Peters6d6c1a32001-08-02 04:15:00 +00001324- TENTATIVELY, a large amount of code implementing much of what's
1325 described in PEP 252 (Making Types Look More Like Classes) and PEP
1326 253 (Subtyping Built-in Types) was added. This will be released
1327 with Python 2.2a1. Documentation will be provided separately
1328 through http://www.python.org/2.2/. The purpose of releasing this
1329 with Python 2.2a1 is to test backwards compatibility. It is
1330 possible, though not likely, that a decision is made not to release
1331 this code as part of 2.2 final, if any serious backwards
1332 incompapatibilities are found during alpha testing that cannot be
1333 repaired.
1334
Guido van Rossum55a78992001-07-17 17:22:32 +00001335- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001336 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001337 more 'yield' statements. See PEP 255. Since this adds a new
1338 keyword to the language, this feature must be enabled by including a
1339 future statement: "from __future__ import generators" (see PEP 236).
1340 Generators will become a standard feature in a future release
1341 (probably 2.3). Without this future statement, 'yield' remains an
1342 ordinary identifier, but a warning is issued each time it is used.
1343 (These warnings currently don't conform to the warnings framework of
1344 PEP 230; we intend to fix this in 2.2a2.)
1345
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001346- The UTF-16 codec was modified to be more RFC compliant. It will now
1347 only remove BOM characters at the start of the string and then
1348 only if running in native mode (UTF-16-LE and -BE won't remove a
1349 leading BMO character).
1350
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001351- Strings now have a new method .decode() to complement the already
1352 existing .encode() method. These two methods provide direct access
1353 to the corresponding decoders and encoders of the registered codecs.
1354
1355 To enhance the usability of the .encode() method, the special
1356 casing of Unicode object return values was dropped (Unicode objects
1357 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001358
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001359 Both methods will now return whatever the codec in charge of the
1360 requested encoding returns as object, e.g. Unicode codecs will
1361 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1362 will return u"äöü"). This enables codec writer to create codecs
1363 for various simple to use conversions.
1364
1365 New codecs were added to demonstrate these new features (the .encode()
1366 and .decode() columns indicate the type of the returned objects):
1367
1368 Name | .encode() | .decode() | Description
1369 ----------------------------------------------------------------------
1370 uu | string | string | UU codec (e.g. for email)
1371 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001372 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001373 zlib | string | string | zlib compression
1374 hex | string | string | 2-byte hex codec
1375 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1376
Mark Hammond2a0af792001-05-14 03:09:36 +00001377- Some operating systems now support the concept of a default Unicode
1378 encoding for file system operations. Notably, Windows supports 'mbcs'
1379 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001380 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001381 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001382
1383 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001384 functions that return filenames (such as os.listdir()) to return Python
1385 string objects pre-encoded using the default file system encoding for
1386 the platform. As this encoding is likely to be different from Python's
1387 default encoding, converting this name to a Unicode object before passing
1388 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001389 would attempt to use its default encoding (generally ASCII) rather than
1390 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001391
Tim Petersa814db52001-05-14 07:05:58 +00001392 In general, this change simply removes surprises when working with
1393 Unicode and the file system, making these operations work as you expect,
1394 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001395 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001396
Tim Peters61dff2b2001-05-08 15:43:37 +00001397- Float (and complex) literals in source code were evaluated to full
1398 precision only when running from a .py file; the same code loaded from a
1399 .pyc (or .pyo) file could suffer numeric differences starting at about the
1400 12th significant decimal digit. For example, on a machine with IEEE-754
1401 floating arithmetic,
1402
1403 x = 9007199254740992.0
1404 print long(x)
1405
1406 printed 9007199254740992 if run directly from .py, but 9007199254740000
1407 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1408 str(float) instead of repr(float) when building code objects. marshal
1409 now uses repr(float) instead, which should reproduce floats to full
1410 machine precision (assuming the platform C float<->string I/O conversion
1411 functions are of good quality).
1412
1413 This may cause floating-point results to change in some cases, and
1414 usually for the better, but may also cause numerically unstable
1415 algorithms to break.
1416
Tim Peters2f228e72001-05-13 00:19:31 +00001417- The implementation of dicts suffers fewer collisions, which has speed
1418 benefits. However, the order in which dict entries appear in dict.keys(),
1419 dict.values() and dict.items() may differ from previous releases for a
1420 given dict. Nothing is defined about this order, so no program should
1421 rely on it. Nevertheless, it's easy to write test cases that rely on the
1422 order by accident, typically because of printing the str() or repr() of a
1423 dict to an "expected results" file. See Lib/test/test_support.py's new
1424 sortdict(dict) function for a simple way to display a dict in sorted
1425 order.
1426
Tim Peters7a3bfc32001-06-12 01:22:22 +00001427- Many other small changes to dicts were made, resulting in faster
1428 operation along the most common code paths.
1429
Guido van Rossum10315822001-05-01 20:54:30 +00001430- Dictionary objects now support the "in" operator: "x in dict" means
1431 the same as dict.has_key(x).
1432
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001433- The update() method of dictionaries now accepts generic mapping
1434 objects. Specifically the argument object must support the .keys()
1435 and __getitem__() methods. This allows you to say, for example,
1436 {}.update(UserDict())
1437
Guido van Rossum10315822001-05-01 20:54:30 +00001438- Iterators were added; this is a generalized way of providing values
1439 to a for loop. See PEP 234. There's a new built-in function iter()
1440 to return an iterator. There's a new protocol to get the next value
1441 from an iterator using the next() method (in Python) or the
1442 tp_iternext slot (in C). There's a new protocol to get iterators
1443 using the __iter__() method (in Python) or the tp_iter slot (in C).
1444 Iterating (i.e. a for loop) over a dictionary generates its keys.
1445 Iterating over a file generates its lines.
1446
Tim Petersf553f892001-05-01 20:45:31 +00001447- The following functions were generalized to work nicely with iterator
1448 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001449 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001450 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1451 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001452 join() method of strings
1453 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001454 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1455 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001456 right-hand side of assignment statements with multiple targets, such as
1457 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001458
Tim Petersd85e1022001-05-11 21:51:48 +00001459- Accessing module attributes is significantly faster (for example,
1460 random.random or os.path or yourPythonModule.yourAttribute).
1461
Tim Peterse63415e2001-05-08 04:38:29 +00001462- Comparing dictionary objects via == and != is faster, and now works even
1463 if the keys and values don't support comparisons other than ==.
1464
Tim Peters95bf9392001-05-10 08:32:44 +00001465- Comparing dictionaries in ways other than == and != is slower: there were
1466 insecurities in the dict comparison implementation that could cause Python
1467 to crash if the element comparison routines for the dict keys and/or
1468 values mutated the dicts. Making the code bulletproof slowed it down.
1469
Tim Peterseb28ef22001-06-02 05:27:19 +00001470- Collisions in dicts are resolved via a new approach, which can help
1471 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001472 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001473 faster now. Thanks to Christian Tismer for pointing out the cause and
1474 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001475
Tim Peters52e155e2001-06-16 05:42:57 +00001476- repr() is much faster for large containers (dict, list, tuple).
1477
1478
Tim Petersa814db52001-05-14 07:05:58 +00001479Library
1480
Fred Drake960fdf92001-07-20 18:38:26 +00001481- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1482 were added to the string module. These a locale-indenpendent
1483 constants, unlike letters, lowercase, and uppercase. These are now
1484 use in appropriate locations in the standard library.
1485
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001486- The flags used in dlopen calls can now be configured using
1487 sys.setdlopenflags and queried using sys.getdlopenflags.
1488
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001489- Fredrik Lundh's xmlrpclib is now a standard library module. This
1490 provides full client-side XML-RPC support. In addition,
1491 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1492 one asyncore-based). Thanks to Eric Raymond for the documentation.
1493
Guido van Rossum643d3912001-07-05 14:46:25 +00001494- The xrange() object is simplified: it no longer supports slicing,
1495 repetition, comparisons, efficient 'in' checking, the tolist()
1496 method, or the start, stop and step attributes. See PEP 260.
1497
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001498- A new function fnmatch.filter to filter lists of file names was added.
1499
Barry Warsawffd674d2001-05-22 16:00:10 +00001500- calendar.py uses month and day names based on the current locale.
1501
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001502- strop is now *really* obsolete (this was announced before with 1.6),
1503 and issues DeprecationWarning when used (except for the four items
1504 that are still imported into string.py).
1505
Tim Petersa814db52001-05-14 07:05:58 +00001506- Cookie.py now sorts key+value pairs by key in output strings.
1507
1508- pprint.isrecursive(object) didn't correctly identify recursive objects.
1509 Now it does.
1510
Tim Peters95b3f782001-05-14 18:39:41 +00001511- pprint functions now much faster for large containers (tuple, list, dict).
1512
Tim Peters7b9542a2001-06-10 23:40:19 +00001513- New 'q' and 'Q' format codes in the struct module, corresponding to C
1514 types "long long" and "unsigned long long" (on Windows, __int64). In
1515 native mode, these can be used only when the platform C compiler supports
1516 these types (when HAVE_LONG_LONG is #define'd by the Python config
1517 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001518 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1519 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001520
Guido van Rossum83213cc2001-06-12 16:48:52 +00001521- The site module installs a new built-in function 'help' that invokes
1522 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1523 it displays a message reminding the user to use 'help()' or
1524 'help(object)'.
1525
Tim Petersa814db52001-05-14 07:05:58 +00001526Tests
1527
1528- New test_mutants.py runs dict comparisons where the key and value
1529 comparison operators mutute the dicts randomly during comparison. This
1530 rapidly causes Python to crash under earlier releases (not for the faint
1531 of heart: it can also cause Win9x to freeze or reboot!).
1532
1533- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001534 pprint.isreadable() return sensible results. Also verifies that simple
1535 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001536
Tim Peters4324aa32001-05-28 22:30:08 +00001537C API
1538
1539- Removed the unused last_is_sticky argument from the internal
1540 _PyTuple_Resize(). If this affects you, you were cheating.
1541
1542
Guido van Rossum55a78992001-07-17 17:22:32 +00001543======================================================================
1544
1545
Guido van Rossumffe13be2001-04-16 18:46:45 +00001546What's New in Python 2.1 (final)?
1547=================================
1548
1549We only changed a few things since the last release candidate, all in
1550Python library code:
1551
1552- A bug in the locale module was fixed that affected locales which
1553 define no grouping for numeric formatting.
1554
1555- A few bugs in the weakref module's implementations of weak
1556 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1557 and the test suite was updated to check for these bugs.
1558
1559- An old bug in the os.path.walk() function (introduced in Python
1560 2.0!) was fixed: a non-existent file would cause an exception
1561 instead of being ignored.
1562
1563- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1564 PyChecker.
1565
1566
Guido van Rossum5b08f132001-04-16 02:05:23 +00001567What's New in Python 2.1c2?
1568===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001569
Guido van Rossum5b08f132001-04-16 02:05:23 +00001570A flurry of small changes, and one showstopper fixed in the nick of
1571time made it necessary to release another release candidate. The list
1572here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001573
Guido van Rossum5b08f132001-04-16 02:05:23 +00001574Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001575
Guido van Rossum5b08f132001-04-16 02:05:23 +00001576- Tim discovered a nasty bug in the dictionary code, caused by
1577 PyDict_Next() calling dict_resize(), and the GC code's use of
1578 PyDict_Next() violating an assumption in dict_items(). This was
1579 fixed with considerable amounts of band-aid, but the net effect is a
1580 saner and more robust implementation.
1581
1582- Made a bunch of symbols static that were accidentally global.
1583
1584Build and Ports
1585
1586- The setup.py script didn't check for a new enough version of zlib
1587 (1.1.3 is needed). Now it does.
1588
1589- Changed "make clean" target to also remove shared libraries.
1590
1591- Added a more general warning about the SGI Irix optimizer to README.
1592
1593Library
1594
1595- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1596 omitted the slash between host and file.html.
1597
1598- The mailbox module's _Mailbox class contained a completely broken
1599 and undocumented seek() method. Ripped it out.
1600
1601- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1602 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1603
1604- Fixed a few last-minute bugs in unittest.
1605
1606Extensions
1607
1608- Reverted the patch to the OpenSSL code in socketmodule.c to support
1609 RAND_status() and the EGD, and the subsequent patch that tried to
1610 fix it for pre-0.9.5 versions; the problem with the patch is that on
1611 some systems it issues a warning whenever socket is imported, and
1612 that's unacceptable.
1613
1614Tests
1615
1616- Fixed the pickle tests to work with "import test.test_pickle".
1617
1618- Tweaked test_locale.py to actually run the test Windows.
1619
1620- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1621 not "wb" (which is not a valid mode at all).
1622
1623- Fix pstats browser crashes. Import readline if it exists to make
1624 the user interface nicer.
1625
1626- Add "import thread" to the top of test modules that import the
1627 threading module (test_asynchat and test_threadedtempfile). This
1628 prevents test failures caused by a broken threading module resulting
1629 from a previously caught failed import.
1630
1631- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1632 needed on some platforms (e.g. Solaris 8) when the tests are run
1633 twice in succession.
1634
1635- Skip rather than fail test_sunaudiodev if no audio device is found.
1636
1637
1638What's New in Python 2.1c1?
1639===========================
1640
1641This list was significantly updated when 2.1c2 was released; the 2.1c1
1642release didn't mention most changes that were actually part of 2.1c1:
1643
1644Legal
1645
1646- Copyright was assigned to the Python Software Foundation (PSF) and a
1647 PSF license (very similar to the CNRI license) was added.
1648
1649- The CNRI copyright notice was updated to include 2001.
1650
1651Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001652
Guido van Rossumc9932722001-04-12 02:31:27 +00001653- After a public outcry, assignment to __debug__ is no longer illegal;
1654 instead, a warning is issued. It will become illegal in 2.2.
1655
Guido van Rossum5b08f132001-04-16 02:05:23 +00001656- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1657 "%#x" now always prepends "0x", even if the value is zero.
1658
1659- Fixed some nits in the bytecode compiler.
1660
1661- Fixed core dumps when calling certain kinds of non-functions.
1662
1663- Fixed various core dumps caused by reference count bugs.
1664
1665Build and Ports
1666
1667- Use INSTALL_SCRIPT to install script files.
1668
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001669- New port: SCO Unixware 7, by Billy G. Allie.
1670
Guido van Rossum5b08f132001-04-16 02:05:23 +00001671- Updated RISCOS port.
1672
1673- Updated BeOS port and notes.
1674
1675- Various other porting problems resolved.
1676
1677Library
1678
1679- The TERMIOS and SOCKET modules are now truly obsolete and
1680 unnecessary. Their symbols are incorporated in the termios and
1681 socket modules.
1682
1683- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1684 better tests for pickling.
1685
1686- threading: make Condition.wait() robust against KeyboardInterrupt.
1687
1688- zipfile: add support to zipfile to support opening an archive
1689 represented by an open file rather than a file name. Fix bug where
1690 the archive was not properly closed. Fixed a bug in this bugfix
1691 where flush() was called for a read-only file.
1692
1693- imputil: added an uninstall() method to the ImportManager.
1694
1695- Canvas: fixed bugs in lower() and tkraise() methods.
1696
1697- SocketServer: API change (added overridable close_request() method)
1698 so that the TCP server can explicitly close the request.
1699
1700- pstats: Eric Raymond added a simple interactive statistics browser,
1701 invoked when the module is run as a script.
1702
1703- locale: fixed a problem in format().
1704
1705- webbrowser: made it work when the BROWSER environment variable has a
1706 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1707 KDE 2. Fixed some other nits.
1708
1709- unittest: changes to allow using a different exception than
1710 AssertionError, and added a few more function aliases. Some other
1711 small changes.
1712
1713- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1714
1715- asynchat: fixed a critical bug in asynchat that slipped through the
1716 2.1b2 release. Fixed another rare bug.
1717
1718- Fix some unqualified except: clauses (always a bad code example).
1719
1720XML
1721
1722- pyexpat: new API get_version_string().
1723
1724- Fixed some minidom bugs.
1725
1726Extensions
1727
1728- Fixed a core dump in _weakref. Removed the weakref.mapping()
1729 function (it adds nothing to the API).
1730
1731- Rationalized the use of header files in the readline module, to make
1732 it compile (albeit with some warnings) with the very recent readline
1733 4.2, without breaking for earlier versions.
1734
1735- Hopefully fixed a buffering problem in linuxaudiodev.
1736
1737- Attempted a fix to make the OpenSSL support in the socket module
1738 work again with pre-0.9.5 versions of OpenSSL.
1739
1740Tests
1741
1742- Added a test case for asynchat and asyncore.
1743
1744- Removed coupling between tests where one test failing could break
1745 another.
1746
1747Tools
1748
1749- Ping added an interactive help browser to pydoc, fixed some nits
1750 in the rest of the pydoc code, and added some features to his
1751 inspect module.
1752
1753- An updated python-mode.el version 4.1 which integrates Ken
1754 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1755 much nicer in XEmacs and Emacs. When stepping through your program
1756 with pdb, in either the shell window or the *Python* window, the
1757 source file and line will be tracked by an arrow. Very cool!
1758
1759- IDLE: syntax warnings in interactive mode are changed into errors.
1760
1761- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001762 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001763
1764- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001765
Barry Warsaw11e89c72001-04-11 20:37:57 +00001766
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001767What's New in Python 2.1 beta 2?
1768================================
1769
Guido van Rossum053ae352001-03-22 14:17:21 +00001770(Unlisted are many fixed bugs, more documentation, etc.)
1771
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001772Core language, builtins, and interpreter
1773
Guido van Rossum053ae352001-03-22 14:17:21 +00001774- The nested scopes work (enabled by "from __future__ import
1775 nested_scopes") is completed; in particular, the future now extends
1776 into code executed through exec, eval() and execfile(), and into the
1777 interactive interpreter.
1778
1779- When calling a base class method (e.g. BaseClass.__init__(self)),
1780 this is now allowed even if self is not strictly spoken a class
1781 instance (e.g. when using metaclasses or the Don Beaudry hook).
1782
1783- Slice objects are now comparable but not hashable; this prevents
1784 dict[:] from being accepted but meaningless.
1785
1786- Complex division is now calculated using less braindead algorithms.
1787 This doesn't change semantics except it's more likely to give useful
1788 results in extreme cases. Complex repr() now uses full precision
1789 like float repr().
1790
1791- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1792
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001793- It is illegal to assign to the name __debug__, which is set when the
1794 interpreter starts. It is effectively a compile-time constant.
1795
1796- A warning will be issued if a global statement for a variable
1797 follows a use or assignment of that variable.
1798
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001799Standard library
1800
Guido van Rossum053ae352001-03-22 14:17:21 +00001801- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1802 inspired by JUnit), is now part of the standard library. You now
1803 have a choice of two testing frameworks: unittest requires you to
1804 write testcases as separate code, doctest gathers them from
1805 docstrings. Both approaches have their advantages and
1806 disadvantages.
1807
1808- A new module Tix was added, which wraps the Tix extension library
1809 for Tk. With that module, it is not necessary to statically link
1810 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1811 require" command. See Demo/tix/.
1812
1813- tzparse.py is now obsolete.
1814
1815- In gzip.py, the seek() and tell() methods are removed -- they were
1816 non-functional anyway, and it's better if callers can test for their
1817 existence with hasattr().
1818
1819Python/C API
1820
1821- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1822 that's already in the dictionary during a PyDict_Next() iteration.
1823 This used to fail occasionally when a dictionary resize operation
1824 could be triggered that would rehash all the keys. All other
1825 modifications to the dictionary are still off-limits during a
1826 PyDict_Next() iteration!
1827
1828- New extended APIs related to passing compiler variables around.
1829
1830- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1831 implement isinstance() and issubclass().
1832
1833- Py_BuildValue() now has a "D" conversion to create a Python complex
1834 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001835
Fred Drake4e262a92001-03-22 18:26:47 +00001836- Extensions types which support weak references must now set the
1837 field allocated for the weak reference machinery to NULL themselves;
1838 this is done to avoid the cost of checking each object for having a
1839 weakly referencable type in PyObject_INIT(), since most types are
1840 not weakly referencable.
1841
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001842- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1843 free variables and cell variables to and from the frame's f_locals.
1844
1845- Variants of several functions defined in pythonrun.h have been added
1846 to support the nested_scopes future statement. The variants all end
1847 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1848 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1849 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001850 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001851
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001852Distutils
1853
1854- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1855 into the release tree.
1856
Tim Peters0e57abf2001-05-02 07:39:38 +00001857- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001858 (an uninstaller, more customization of the installer's display)
1859
1860- from Jack Jansen: added Mac-specific code to generate a dialog for
1861 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001862 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001863 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001864
1865- added 'platforms' and 'keywords' to the set of metadata that can be
1866 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001867
1868- applied patches from Jason Tishler to make the compiler class work with
1869 Cygwin.
1870
1871
Tim Peters2fe289a2001-03-01 22:19:38 +00001872What's New in Python 2.1 beta 1?
1873================================
Tim Petersd66595f2001-02-04 03:09:53 +00001874
1875Core language, builtins, and interpreter
1876
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001877- Following an outcry from the community about the amount of code
1878 broken by the nested scopes feature introduced in 2.1a2, we decided
1879 to make this feature optional, and to wait until Python 2.2 (or at
1880 least 6 months) to make it standard. The option can be enabled on a
1881 per-module basis by adding "from __future__ import nested_scopes" at
1882 the beginning of a module (before any other statements, but after
1883 comments and an optional docstring). See PEP 236 (Back to the
1884 __future__) for a description of the __future__ statement. PEP 227
1885 (Statically Nested Scopes) has been updated to reflect this change,
1886 and to clarify the semantics in a number of endcases.
1887
1888- The nested scopes code, when enabled, has been hardened, and most
1889 bugs and memory leaks in it have been fixed.
1890
1891- Compile-time warnings are now generated for a number of conditions
1892 that will break or change in meaning when nested scopes are enabled:
1893
1894 - Using "from...import *" or "exec" without in-clause in a function
1895 scope that also defines a lambda or nested function with one or
1896 more free (non-local) variables. The presence of the import* or
1897 bare exec makes it impossible for the compiler to determine the
1898 exact set of local variables in the outer scope, which makes it
1899 impossible to determine the bindings for free variables in the
1900 inner scope. To avoid the warning about import *, change it into
1901 an import of explicitly name object, or move the import* statement
1902 to the global scope; to avoid the warning about bare exec, use
1903 exec...in... (a good idea anyway -- there's a possibility that
1904 bare exec will be deprecated in the future).
1905
1906 - Use of a global variable in a nested scope with the same name as a
1907 local variable in a surrounding scope. This will change in
1908 meaning with nested scopes: the name in the inner scope will
1909 reference the variable in the outer scope rather than the global
1910 of the same name. To avoid the warning, either rename the outer
1911 variable, or use a global statement in the inner function.
1912
Neil Schemenauera35c6882001-02-27 04:45:05 +00001913- An optional object allocator has been included. This allocator is
1914 optimized for Python objects and should be faster and use less memory
1915 than the standard system allocator. It is not enabled by default
1916 because of possible thread safety problems. The allocator is only
1917 protected by the Python interpreter lock and it is possible that some
1918 extension modules require a thread safe allocator. The object
1919 allocator can be enabled by providing the "--with-pymalloc" option to
1920 configure.
1921
Tim Petersd66595f2001-02-04 03:09:53 +00001922Standard library
1923
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001924- pyexpat now detects the expat version if expat.h defines it. A
1925 number of additional handlers are provided, which are only available
1926 since expat 1.95. In addition, the methods SetParamEntityParsing and
1927 GetInputContext of Parser objects are available with 1.95.x
1928 only. Parser objects now provide the ordered_attributes and
1929 specified_attributes attributes. A new module expat.model was added,
1930 which offers a number of additional constants if 1.95.x is used.
1931
1932- xml.dom offers the new functions registerDOMImplementation and
1933 getDOMImplementation.
1934
1935- xml.dom.minidom offers a toprettyxml method. A number of DOM
1936 conformance issues have been resolved. In particular, Element now
1937 has an hasAttributes method, and the handling of namespaces was
1938 improved.
1939
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001940- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1941 getting information about live Python code, and pydoc.py, a module
1942 for interactively converting docstrings to HTML or text.
1943 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001944 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001945 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1946 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001947
Tim Peters1eff7962001-03-01 02:31:33 +00001948- New library module difflib.py, primarily packaging the SequenceMatcher
1949 class at the heart of the popular ndiff.py file-comparison tool.
1950
1951- doctest.py (a framework for verifying Python code examples in docstrings)
1952 is now part of the std library.
1953
Tim Petersd66595f2001-02-04 03:09:53 +00001954Windows changes
1955
Guido van Rossume3955a82001-03-02 14:05:59 +00001956- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1957 small GUI that lets you browse the module docstrings using your
1958 default web browser.
1959
Tim Peters1eff7962001-03-01 02:31:33 +00001960- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1961 Platforms) is implemented. See
1962
1963 http://python.sourceforge.net/peps/pep-0235.html
1964
1965 for full details, especially the "Current Lower-Left Semantics" section.
1966 The new Windows import rules are simpler than before:
1967
1968 A. If the PYTHONCASEOK environment variable exists, same as
1969 before: silently accept the first case-insensitive match of any
1970 kind; raise ImportError if none found.
1971
1972 B. Else search sys.path for the first case-sensitive match; raise
1973 ImportError if none found.
1974
1975 The same rules have been implented on other platforms with case-
1976 insensitive but case-preserving filesystems too (including Cygwin, and
1977 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001978
Tim Peters25a9ce32001-02-19 07:06:36 +00001979- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1980 what it's supposed to do (and does do under NT and 2000) via direct
1981 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001982 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001983 all Win9x systems before.
1984
Tim Peters1eff7962001-03-01 02:31:33 +00001985- Build: Subproject _test (effectively) renamed to _testcapi.
1986
Tim Peters2fe289a2001-03-01 22:19:38 +00001987New platforms
1988
1989- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1990 Thanks to Steven Majewski!
1991
1992- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1993 Tishler!
1994
Guido van Rossum9089b272001-03-02 06:49:50 +00001995- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1996 Schwertberger! See RISCOS/README for more information -- it seems
1997 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001998 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001999
Tim Peters25a9ce32001-02-19 07:06:36 +00002000
Tim Petersd7b5e882001-01-25 03:36:26 +00002001What's New in Python 2.1 alpha 2?
2002=================================
Tim Peters40ead762001-01-27 05:35:26 +00002003
Tim Petersd7b5e882001-01-25 03:36:26 +00002004Core language, builtins, and interpreter
2005
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002006- Scopes nest. If a name is used in a function or class, but is not
2007 local, the definition in the nearest enclosing function scope will
2008 be used. One consequence of this change is that lambda statements
2009 could reference variables in the namespaces where the lambda is
2010 defined. In some unusual cases, this change will break code.
2011
2012 In all previous version of Python, names were resolved in exactly
2013 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002014 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002015 function A is defined within a function B, the names bound in B are
2016 not visible in A. The new rules make names bound in B visible in A,
2017 unless A contains a name binding that hides the binding in B.
2018
2019 Section 4.1 of the reference manual describes the new scoping rules
2020 in detail. The test script in Lib/test/test_scope.py demonstrates
2021 some of the effects of the change.
2022
2023 The new rules will cause existing code to break if it defines nested
2024 functions where an outer function has local variables with the same
2025 name as globals or builtins used by the inner function. Example:
2026
2027 def munge(str):
2028 def helper(x):
2029 return str(x)
2030 if type(str) != type(''):
2031 str = helper(str)
2032 return str.strip()
2033
2034 Under the old rules, the name str in helper() is bound to the
2035 builtin function str(). Under the new rules, it will be bound to
2036 the argument named str and an error will occur when helper() is
2037 called.
2038
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002039- The compiler will report a SyntaxError if "from ... import *" occurs
2040 in a function or class scope. The language reference has documented
2041 that this case is illegal, but the compiler never checked for it.
2042 The recent introduction of nested scope makes the meaning of this
2043 form of name binding ambiguous. In a future release, the compiler
2044 may allow this form when there is no possibility of ambiguity.
2045
Tim Peters40ead762001-01-27 05:35:26 +00002046- repr(string) is easier to read, now using hex escapes instead of octal,
2047 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2048
2049 >>> "\texample \r\n" + chr(0) + chr(255)
2050 '\texample \r\n\x00\xff' # in 2.1
2051 '\011example \015\012\000\377' # in 2.0
2052
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002053- Functions are now compared and hashed by identity, not by value, since
2054 the func_code attribute is writable.
2055
Fred Drakefb9d7122001-02-01 20:00:40 +00002056- Weak references (PEP 205) have been added. This involves a few
2057 changes in the core, an extension module (_weakref), and a Python
2058 module (weakref). The weakref module is the public interface. It
2059 includes support for "explicit" weak references, proxy objects, and
2060 mappings with weakly held values.
2061
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002062- A 'continue' statement can now appear in a try block within the body
2063 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002064 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002065
Tim Petersd7b5e882001-01-25 03:36:26 +00002066Standard library
2067
Barry Warsaw30dbd142001-01-31 22:14:01 +00002068- mailbox.py now has a new class, PortableUnixMailbox which is
2069 identical to UnixMailbox but uses a more portable scheme for
2070 determining From_ separators. Also, the constructors for all the
2071 classes in this module have a new optional `factory' argument, which
2072 is a callable used when new message classes must be instantiated by
2073 the next() method.
2074
Tim Petersd7b5e882001-01-25 03:36:26 +00002075- random.py is now self-contained, and offers all the functionality of
2076 the now-deprecated whrandom.py. See the docs for details. random.py
2077 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002078 and restoring the internal state of the generator; and jumpahead(n),
2079 for quickly forcing the internal state to be the same as if n calls to
2080 random() had been made. The latter is particularly useful for multi-
2081 threaded programs, creating one instance of the random.Random() class for
2082 each thread, then using .jumpahead() to force each instance to use a
2083 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002084
Tim Peters0de88fc2001-02-01 04:59:18 +00002085- random.py's seed() function is new. For bit-for-bit compatibility with
2086 prior releases, use the whseed function instead. The new seed function
2087 addresses two problems: (1) The old function couldn't produce more than
2088 about 2**24 distinct internal states; the new one about 2**45 (the best
2089 that can be done in the Wichmann-Hill generator). (2) The old function
2090 sometimes produced identical internal states when passed distinct
2091 integers, and there was no simple way to predict when that would happen;
2092 the new one guarantees to produce distinct internal states for all
2093 arguments in [0, 27814431486576L).
2094
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002095- The socket module now supports raw packets on Linux. The socket
2096 family is AF_PACKET.
2097
Tim Peters9ea17ac2001-02-02 05:57:15 +00002098- test_capi.py is a start at running tests of the Python C API. The tests
2099 are implemented by the new Modules/_testmodule.c.
2100
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002101- A new extension module, _symtable, provides provisional access to the
2102 internal symbol table used by the Python compiler. A higher-level
2103 interface will be added on top of _symtable in a future release.
2104
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002105- Removed the obsolete soundex module.
2106
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002107- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2108 the isSameNode method; NamedNodeMap the get method.
2109
2110- xml.sax.expatreader supports the lexical handler property; it
2111 generates comment, startCDATA, and endCDATA events.
2112
Tim Petersee826f82001-01-31 19:39:44 +00002113Windows changes
2114
2115- Build procedure: the zlib project is built in a different way that
2116 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002117 the zlib binary used. See PCbuild\readme.txt for details. Your old
2118 zlib-related directories can be deleted; you'll need to download fresh
2119 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002120
Tim Peters9ea17ac2001-02-02 05:57:15 +00002121- Build: New subproject _test for the benefit of test_capi.py (see above).
2122
Tim Petersb16c56f2001-02-02 21:24:51 +00002123- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2124 interface to some Python compiler internals).
2125
2126- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002127 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002128
Tim Petersa3a3a032000-11-30 05:22:44 +00002129What's New in Python 2.1 alpha 1?
2130=================================
2131
2132Core language, builtins, and interpreter
2133
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002134- There is a new Unicode companion to the PyObject_Str() API
2135 called PyObject_Unicode(). It behaves in the same way as the
2136 former, but assures that the returned value is an Unicode object
2137 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002138
Guido van Rossumf98eda02001-01-17 15:54:45 +00002139- The comparison operators support "rich comparison overloading" (PEP
2140 207). C extension types can provide a rich comparison function in
2141 the new tp_richcompare slot in the type object. The cmp() function
2142 and the C function PyObject_Compare() first try the new rich
2143 comparison operators before trying the old 3-way comparison. There
2144 is also a new C API PyObject_RichCompare() (which also falls back on
2145 the old 3-way comparison, but does not constrain the outcome of the
2146 rich comparison to a Boolean result).
2147
2148 The rich comparison function takes two objects (at least one of
2149 which is guaranteed to have the type that provided the function) and
2150 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2151 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2152 object, which may be NotImplemented (in which case the tp_compare
2153 slot function is used as a fallback, if defined).
2154
2155 Classes can overload individual comparison operators by defining one
2156 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002157 __ge__. There are no explicit "reflected argument" versions of
2158 these; instead, __lt__ and __gt__ are each other's reflection,
2159 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2160 reflection (similar at the C level). No other implications are
2161 made; in particular, Python does not assume that == is the Boolean
2162 inverse of !=, or that < is the Boolean inverse of >=. This makes
2163 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002164
2165 Classes or types that want to implement (in)equality tests but not
2166 the ordering operators (i.e. unordered types) should implement ==
2167 and !=, and raise an error for the ordering operators.
2168
Guido van Rossuma88479f2001-01-18 14:28:08 +00002169 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002170 Boolean; e.g. a matrix type might want to return a matrix of bits
2171 for A < B, giving elementwise comparisons. Such types should ensure
2172 that any interpretation of their value in a Boolean context raises
2173 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2174 at the C level) to always raise an exception.
2175
Guido van Rossuma88479f2001-01-18 14:28:08 +00002176- Complex numbers use rich comparisons to define == and != but raise
2177 an exception for <, <=, > and >=. Unfortunately, this also means
2178 that cmp() of two complex numbers raises an exception when the two
2179 numbers differ. Since it is not mathematically meaningful to compare
2180 complex numbers except for equality, I hope that this doesn't break
2181 too much code.
2182
Tim Peters3389f192001-02-18 08:48:49 +00002183- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002184 not defined by the language, other than that it's arbitrary but
2185 consistent (see the Reference Manual). An implementation detail changed
2186 in 2.1a1 such that None now compares less than any other object. Code
2187 relying on this new behavior (like code that relied on the previous
2188 behavior) does so at its own risk.
2189
Barry Warsaw573b5412001-01-15 20:43:18 +00002190- Functions and methods now support getting and setting arbitrarily
2191 named attributes (PEP 232). Functions have a new __dict__
2192 (a.k.a. func_dict) which hold the function attributes. Methods get
2193 and set attributes on their underlying im_func. It is a TypeError
2194 to set an attribute on a bound method.
2195
Guido van Rossum051e3352001-01-15 19:11:10 +00002196- The xrange() object implementation has been improved so that
2197 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2198 limitation that in this case len(xrange(sys.maxint)) can't be
2199 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2200 work fine as long as the index i doesn't actually reach 2**31.
2201 (Python uses regular ints for sequence and string indices; fixing
2202 that is much more work.)
2203
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002204- Two changes to from...import:
2205
Guido van Rossumba381232001-02-03 15:06:40 +00002206 1) "from M import X" now works even if (after loading module M)
2207 sys.modules['M'] is not a real module; it's basically a getattr()
2208 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002209
2210 2) "from M import *" now looks for M.__all__ to decide which names to
2211 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2212 filters out names starting with '_' as before. Whether or not
2213 __all__ exists, there's no restriction on the type of M.
2214
Guido van Rossumf61f1662001-01-10 20:13:55 +00002215- File objects have a new method, xreadlines(). This is the fastest
2216 way to iterate over all lines in a file:
2217
2218 for line in file.xreadlines():
2219 ...do something to line...
2220
2221 See the xreadlines module (mentioned below) for how to do this for
2222 other file-like objects.
2223
2224- Even if you don't use file.xreadlines(), you may expect a speedup on
2225 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002226 quite a bit in platform-specific ways: on systems (like Linux) that
2227 support flockfile(), getc_unlocked(), and funlockfile(), those are
2228 used by default. On systems (like Windows) without getc_unlocked(),
2229 a complicated (but still thread-safe) method using fgets() is used by
2230 default.
2231
Tim Petersd52269b2001-01-25 06:23:18 +00002232 You can force use of the fgets() method by #define'ing
2233 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002234 getc_unlocked()).
2235
Tim Petersd52269b2001-01-25 06:23:18 +00002236 You can force fgets() not to be used by #define'ing
2237 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002238 test_bufio.py fails -- and let us know if it does!).
2239
2240- In addition, the fileinput module, while still slower than the other
2241 methods on most platforms, has been sped up too, by using
2242 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002243
2244- Support for run-time warnings has been added, including a new
2245 command line option (-W) to specify the disposition of warnings.
2246 See the description of the warnings module below.
2247
2248- Extensive changes have been made to the coercion code. This mostly
2249 affects extension modules (which can now implement mixed-type
2250 numerical operators without having to use coercion), but
2251 occasionally, in boundary cases the coercion semantics have changed
2252 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002253 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002254 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002255 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002256
Guido van Rossumf98eda02001-01-17 15:54:45 +00002257- In connection with the coercion changes, a new built-in singleton
2258 object, NotImplemented is defined. This can be returned for
2259 operations that wish to indicate they are not implemented for a
2260 particular combination of arguments. From C, this is
2261 Py_NotImplemented.
2262
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002263- The interpreter accepts now bytecode files on the command line even
2264 if they do not have a .pyc or .pyo extension. On Linux, after executing
2265
Martin v. Löwise214baa2001-02-04 22:37:56 +00002266import imp,sys,string
2267magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2268reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2269open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002270
2271 any byte code file can be used as an executable (i.e. as an argument
2272 to execve(2)).
2273
Tim Peters9940b802000-12-01 07:59:35 +00002274- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002275 character. In 1.6 and earlier, they never produced a sign,
2276 and raised an error if the value of the long was too large
2277 to fit in a Python int. In 2.0, they produced a sign if and
2278 only if too large to fit in an int. This was inconsistent
2279 across platforms (because the size of an int varies across
2280 platforms), and inconsistent with hex() and oct(). Example:
2281
2282 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002283 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002284 'ffffffbe' # in 2.0 and before, on 32-bit machines
2285 >>> hex(-0x42L)
2286 '-0x42L' # in all versions of Python
2287
Tim Peters9940b802000-12-01 07:59:35 +00002288 The behavior of %d formats for negative Python longs remains
2289 the same as in 2.0 (although in 1.6 and before, they raised
2290 an error if the long didn't fit in a Python int).
2291
2292 %u formats don't make sense for Python longs, but are allowed
2293 and treated the same as %d in 2.1. In 2.0, a negative long
2294 formatted via %u produced a sign if and only if too large to
2295 fit in an int. In 1.6 and earlier, a negative long formatted
2296 via %u raised an error if it was too big to fit in an int.
2297
Guido van Rossum3661d392000-12-12 22:10:31 +00002298- Dictionary objects have an odd new method, popitem(). This removes
2299 an arbitrary item from the dictionary and returns it (in the form of
2300 a (key, value) pair). This can be useful for algorithms that use a
2301 dictionary as a bag of "to do" items and repeatedly need to pick one
2302 item. Such algorithms normally end up running in quadratic time;
2303 using popitem() they can usually be made to run in linear time.
2304
Tim Peters36cdad12000-12-29 02:06:45 +00002305Standard library
2306
Thomas Woutersfe385252001-01-19 23:16:56 +00002307- In the time module, the time argument to the functions strftime,
2308 localtime, gmtime, asctime and ctime is now optional, defaulting to
2309 the current time (in the local timezone).
2310
Guido van Rossumda91f222001-01-15 16:36:08 +00002311- The ftplib module now defaults to passive mode, which is deemed a
2312 more useful default given that clients are often inside firewalls
2313 these days. Note that this could break if ftplib is used to connect
2314 to a *server* that is inside a firewall, from outside; this is
2315 expected to be a very rare situation. To fix that, you can call
2316 ftp.set_pasv(0).
2317
Martin v. Löwis10a27872001-01-13 09:54:41 +00002318- The module site now treats .pth files not only for path configuration,
2319 but also supports extensions to the initialization code: Lines starting
2320 with import are executed.
2321
Guido van Rossumf61f1662001-01-10 20:13:55 +00002322- There's a new module, warnings, which implements a mechanism for
2323 issuing and filtering warnings. There are some new built-in
2324 exceptions that serve as warning categories, and a new command line
2325 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2326 turns warnings into errors). warnings.warn(message[, category])
2327 issues a warning message; this can also be called from C as
2328 PyErr_Warn(category, message).
2329
2330- A new module xreadlines was added. This exports a single factory
2331 function, xreadlines(). The intention is that this code is the
2332 absolutely fastest way to iterate over all lines in an open
2333 file(-like) object:
2334
2335 import xreadlines
2336 for line in xreadlines.xreadlines(file):
2337 ...do something to line...
2338
2339 This is equivalent to the previous the speed record holder using
2340 file.readlines(sizehint). Note that if file is a real file object
2341 (as opposed to a file-like object), this is equivalent:
2342
2343 for line in file.xreadlines():
2344 ...do something to line...
2345
Tim Peters36cdad12000-12-29 02:06:45 +00002346- The bisect module has new functions bisect_left, insort_left,
2347 bisect_right and insort_right. The old names bisect and insort
2348 are now aliases for bisect_right and insort_right. XXX_right
2349 and XXX_left methods differ in what happens when the new element
2350 compares equal to one or more elements already in the list: the
2351 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002352 right. Code that doesn't care where equal elements end up should
2353 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002354
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002355- The new curses.panel module wraps the panel library that forms part
2356 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2357
Guido van Rossumf61f1662001-01-10 20:13:55 +00002358- The SocketServer module now sets the allow_reuse_address flag by
2359 default in the TCPServer class.
2360
2361- A new function, sys._getframe(), returns the stack frame pointer of
2362 the caller. This is intended only as a building block for
2363 higher-level mechanisms such as string interpolation.
2364
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002365- The pyexpat module supports a number of new handlers, which are
2366 available only in expat 1.2. If invocation of a callback fails, it
2367 will report an additional frame in the traceback. Parser objects
2368 participate now in garbage collection. If expat reports an unknown
2369 encoding, pyexpat will try to use a Python codec; that works only
2370 for single-byte charsets. The parser type objects is exposed as
2371 XMLParserObject.
2372
2373- xml.dom now offers standard definitions for symbolic node type and
2374 exception code constants, and a hierarchy of DOM exceptions. minidom
2375 was adjusted to use them.
2376
2377- The conformance of xml.dom.minidom to the DOM specification was
2378 improved. It detects a number of additional error cases; the
2379 previous/next relationship works even when the tree is modified;
2380 Node supports the normalize() method; NamedNodeMap, DocumentType and
2381 DOMImplementation classes were added; Element supports the
2382 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2383 method.
2384
Guido van Rossumf61f1662001-01-10 20:13:55 +00002385Build issues
2386
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002387- For Unix (and Unix-compatible) builds, configuration and building of
2388 extension modules is now greatly automated. Rather than having to
2389 edit the Modules/Setup file to indicate which modules should be
2390 built and where their include files and libraries are, a
2391 distutils-based setup.py script now takes care of building most
2392 extension modules. All extension modules built this way are built
2393 as shared libraries. Only a few modules that must be linked
2394 statically are still listed in the Setup file; you won't need to
2395 edit their configuration.
2396
2397- Python should now build out of the box on Cygwin. If it doesn't,
2398 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002399
2400- Python now always uses its own (renamed) implementation of getopt()
2401 -- there's too much variation among C library getopt()
2402 implementations.
2403
2404- C++ compilers are better supported; the CXX macro is always set to a
2405 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002406
Tim Petersd92dfe02000-12-12 01:18:41 +00002407Windows changes
2408
2409- select module: By default under Windows, a select() call
2410 can specify no more than 64 sockets. Python now boosts
2411 this Microsoft default to 512. If you need even more than
2412 that, see the MS docs (you'll need to #define FD_SETSIZE
2413 and recompile Python from source).
2414
Guido van Rossumf61f1662001-01-10 20:13:55 +00002415- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2416 subdirectory is no more!
2417
Tim Petersa3a3a032000-11-30 05:22:44 +00002418
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002419What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002420=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002421
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002422Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002423changes are in the file HISTORY. If you are making the jump directly
2424from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2425HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002426
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002427Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2428the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2429http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002430
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002431--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002432
2433======================================================================
2434
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002435What's new in 2.0 (since release candidate 1)?
2436==============================================
2437
2438Standard library
2439
2440- The copy_reg module was modified to clarify its intended use: to
2441 register pickle support for extension types, not for classes.
2442 pickle() will raise a TypeError if it is passed a class.
2443
2444- Fixed a bug in gettext's "normalize and expand" code that prevented
2445 it from finding an existing .mo file.
2446
2447- Restored support for HTTP/0.9 servers in httplib.
2448
Tim Peters989b7b92000-10-16 20:24:53 +00002449- The math module was changed to stop raising OverflowError in case of
2450 underflow, and return 0 instead in underflow cases. Whether Python
2451 used to raise OverflowError in case of underflow was platform-
2452 dependent (it did when the platform math library set errno to ERANGE
2453 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002454
2455- Fixed a bug in StringIO that occurred when the file position was not
2456 at the end of the file and write() was called with enough data to
2457 extend past the end of the file.
2458
2459- Fixed a bug that caused Tkinter error messages to get lost on
2460 Windows. The bug was fixed by replacing direct use of
2461 interp->result with Tcl_GetStringResult(interp).
2462
2463- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2464 redirect response.
2465
2466- Several changes were made to distutils: Some debugging code was
2467 removed from util. Fixed the installer used when an external zip
2468 program (like WinZip) is not found; the source code for this
2469 installer is in Misc/distutils. check_lib() was modified to behave
2470 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2471 test for whether installed modules are on sys.path was changed to
2472 use both normcase() and normpath().
2473
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002474- Several minor bugs were fixed in the xml package (the minidom,
2475 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002476
2477- The regression test driver (regrtest.py) behavior when invoked with
2478 -l changed: It now reports a count of objects that are recognized as
2479 garbage but not freed by the garbage collector.
2480
Tim Peters989b7b92000-10-16 20:24:53 +00002481- The regression test for the math module was changed to test
2482 exceptional behavior when the test is run in verbose mode. Python
2483 cannot yet guarantee consistent exception behavior across platforms,
2484 so the exception part of test_math is run only in verbose mode, and
2485 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002486
2487Internals
2488
2489- PyOS_CheckStack() has been disabled on Win64, where it caused
2490 test_sre to fail.
2491
2492Build issues
2493
2494- Changed compiler flags, so that gcc is always invoked with -Wall and
2495 -Wstrict-prototypes. Users compiling Python with GCC should see
2496 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002497 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002498 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002499
Tim Petersa3a3a032000-11-30 05:22:44 +00002500- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002501
2502Tools and other miscellany
2503
2504- The compiler in Tools/compiler was updated to support the new
2505 language features introduced in 2.0: extended print statement, list
2506 comprehensions, and augmented assignments. The new compiler should
2507 also be backwards compatible with Python 1.5.2; the compiler will
2508 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002509 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002510
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002511What's new in 2.0 release candidate 1 (since beta 2)?
2512=====================================================
2513
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002514What is release candidate 1?
2515
2516We believe that release candidate 1 will fix all known bugs that we
2517intend to fix for the 2.0 final release. This release should be a bit
2518more stable than the previous betas. We would like to see even more
2519widespread testing before the final release, so we are producing this
2520release candidate. The final release will be exactly the same unless
2521any show-stopping (or brown bag) bugs are found by testers of the
2522release candidate.
2523
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002524All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002525to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002526
2527Core language, builtins, and interpreter
2528
2529- A bug that caused crashes when __coerce__ was used with augmented
2530 assignment, e.g. +=, was fixed.
2531
2532- Raise ZeroDivisionError when raising zero to a negative number,
2533 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2534 power operator and the result of math.pow(0.0, -2.0) will vary by
2535 platform. On Linux, it raises a ValueError.
2536
2537- A bug in Unicode string interpolation was fixed that occasionally
2538 caused errors with formats including "%%". For example, the
2539 following expression "%% %s" % u"abc" no longer raises a TypeError.
2540
2541- Compilation of deeply nested expressions raises MemoryError instead
2542 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2543
2544- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2545 rendering them useless. They are now written in binary mode again.
2546
2547Standard library
2548
2549- Keyword arguments are now accepted for most pattern and match object
2550 methods in SRE, the standard regular expression engine.
2551
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002552- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002553 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002554
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002555- Several bugs in the Unicode handling and error handling in _tkinter
2556 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002557
2558- Fix memory management errors in Merge() and Tkapp_Call() routines.
2559
2560- Several changes were made to cStringIO to make it compatible with
2561 the file-like object interface and with StringIO. If operations are
2562 performed on a closed object, an exception is raised. The truncate
2563 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002564 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002565
2566- There were many changes made to the linuxaudiodev module and its
2567 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002568 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002569
2570 Note that this module is named poorly, because it should work
2571 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002572 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002573
2574 The module now raises exceptions when errors occur instead of
2575 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2576 audio) and defines a getptr() method that calls the
2577 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2578
2579- The library_version attribute, introduced in an earlier beta, was
2580 removed because it can not be supported with early versions of the C
2581 readline library, which provides no way to determine the version at
2582 compile-time.
2583
2584- The binascii module is now enabled on Win64.
2585
Tim Peters46446d62000-10-09 21:19:31 +00002586- tokenize.py no longer suffers "recursion depth" errors when parsing
2587 programs with very long string literals.
2588
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002589Internals
2590
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002591- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002592 which is called when the interpreter starts up to determine where
2593 the standard library is installed. These vulnerabilities affect all
2594 previous versions of Python and can be exploited by setting very
2595 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2596 setuid Python script, although use of the wrapper in
2597 Misc/setuid-prog.c will eliminate the vulnerability.
2598
2599- Fixed garbage collection bugs in instance creation that were
2600 triggered when errors occurred during initialization. The solution,
2601 applied in cPickle and in PyInstance_New(), is to call
2602 PyObject_GC_Init() after the initialization of the object's
2603 container attributes is complete.
2604
2605- pyexpat adds definitions of PyModule_AddStringConstant and
2606 PyModule_AddObject if the Python version is less than 2.0, which
2607 provides compatibility with PyXML on Python 1.5.2.
2608
2609- If the platform has a bogus definition for LONG_BIT (the number of
2610 bits in a long), an error will be reported at compile time.
2611
2612- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2613 collection crashes and possibly other, unreported crashes.
2614
2615- Fixed a memory leak in _PyUnicode_Fini().
2616
2617Build issues
2618
2619- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002620 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002621 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002622
2623- The mmap.PAGESIZE constant is now initialized using sysconf when
2624 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2625
2626- The md5 file should now compile on all platforms.
2627
2628- The select module now compiles on platforms that do not define
2629 POLLRDNORM and related constants.
2630
2631- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002632 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002633
Jeremy Hylton10921202000-10-09 18:34:12 +00002634- BeOS: A number of changes were made to the build and installation
2635 process. ar-fake now operates on a directory of object files.
2636 dl_export.h is gone, and its macros now appear on the mwcc command
2637 line during build on PPC BeOS.
2638
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002639- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002640 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002641
2642- Cygwin: Support for shared libraries, Tkinter, and sockets.
2643
2644- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2645
2646Tools and other miscellany
2647
2648- Removed debugging prints from main used with freeze.
2649
Tim Peters46446d62000-10-09 21:19:31 +00002650- IDLE auto-indent no longer crashes when it encounters Unicode
2651 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002652
2653What's new in 2.0 beta 2 (since beta 1)?
2654========================================
2655
2656Core language, builtins, and interpreter
2657
Tim Peters482c0212000-09-26 06:33:09 +00002658- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002659 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002660
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002661- Add -h and -V command line options to print the usage message and
2662 Python version number and exit immediately.
2663
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002664- eval() and exec accept Unicode objects as code parameters.
2665
2666- getattr() and setattr() now also accept Unicode objects for the
2667 attribute name, which are converted to strings using the default
2668 encoding before lookup.
2669
2670- Multiplication on string and Unicode now does proper bounds
2671 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2672 string is too long."
2673
2674- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002675 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002676
Jeremy Hylton1b618592000-09-26 05:32:36 +00002677
2678Standard library and extensions
2679
Guido van Rossum5b08f132001-04-16 02:05:23 +00002680- socket module: the OpenSSL code now adds support for RAND_status()
2681 and EGD (Entropy Gathering Device).
2682
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002683- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002684 argument checking; it still takes no arguments.
2685
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002686- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002687
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002688- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002689
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002690- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002691
2692- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002693 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002694
2695- copy: Copy Unicode objects atomically.
2696
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002697- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002698
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002699- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002700
Fred Drake67233bc2000-09-26 16:40:27 +00002701- dbm: Add get() and setdefault() methods to dbm object. Add constant
2702 `library' to module that names the library used. Added doc strings
2703 and method names to error messages. Uses configure to determine
2704 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2705 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002706
2707- distutils: Update to version 0.9.3.
2708
2709- dl: Add several dl.RTLD_ constants.
2710
2711- fpectl: Now supported on FreeBSD.
2712
2713- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2714 found by the collector will be saved in gc.garbage. This is useful
2715 for debugging a program that creates reference cycles.
2716
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002717- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718 of HTTP class. Do not close socket on zero-length response. Do not
2719 crash when server sends invalid content-length header.
2720
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002721- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002722
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002723- marshal: When reading a short, sign-extend on platforms where shorts
2724 are bigger than 16 bits. When reading a long, repair the unportable
2725 sign extension that was being done for 64-bit machines. (It assumed
2726 that signed right shift sign-extends.)
2727
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002728- operator: Add contains(), invert(), __invert__() as aliases for
2729 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002730
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002731- os: Add support for popen2() and popen3() on all platforms where
2732 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002733
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002734- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002735 clicking on a file in Explorer (or passing the file name to the
2736 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002737
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002738- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002739 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002740
2741- pickle: Now raises ValueError when an invalid pickle that contains
2742 a non-string repr where a string repr was expected. This behavior
2743 matches cPickle.
2744
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002745- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002746
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002747- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002748
2749- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002750 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002751 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002752
2753- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002754 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002755
2756- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002757 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002758 few cycles during startup since the first call to
2759 setdefaultencoding() will initialize the codec registry and the
2760 encodings package.
2761
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002762- socket: Support for size hint in readlines() method of object returned
2763 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002764
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002765- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002766 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002767 is followed by whitespace.
2768
Tim Petersa3a3a032000-11-30 05:22:44 +00002769- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002770
2771- struct: Check ranges for bytes and shorts.
2772
2773- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002774 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002775
2776- Tkinter: Image objects are now guaranteed to have unique ids. Set
2777 event.delta to zero if Tk version doesn't support mousewheel.
2778 Removed some debugging prints.
2779
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002780- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002781
Fred Drake67233bc2000-09-26 16:40:27 +00002782- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002783 which works around a bug in Norton AntiVirus 2000 that leads directly
2784 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002785
2786- xml: New version detection code allows PyXML to override standard
2787 XML package if PyXML version is greater than 0.6.1.
2788
Fred Drake64bb3802000-09-26 16:21:35 +00002789- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2790 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2791 tree only for nodes which are sufficiently interesting to a specific
2792 application. Does not provide the HTML-specific extensions. Still
2793 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002794
Fred Drake64bb3802000-09-26 16:21:35 +00002795- xml.sax: SAX 2 support for Python, including all the handler
2796 interfaces needed to process XML 1.0 compliant XML. Some
2797 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002798
Fred Drake64bb3802000-09-26 16:21:35 +00002799- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2800 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002801
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002802
Jeremy Hylton1b618592000-09-26 05:32:36 +00002803C API
2804
2805- Add three new convenience functions for module initialization --
2806 PyModule_AddObject(), PyModule_AddIntConstant(), and
2807 PyModule_AddStringConstant().
2808
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002809- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002810 removed and add #error to Python.h if NULL isn't defined after
2811 #include of stdio.h.
2812
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002813- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002814 backwards compatibility (at the source level) with old extensions.
2815
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002816- A wrapper API was added for signal() and sigaction(). Instead of
2817 either function, always use PyOS_getsig() to get a signal handler
2818 and PyOS_setsig() to set one. A new convenience typedef
2819 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002820
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002821- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002822 internal data buffer and size of a string object -- or the default
2823 encoded version of a Unicode object.
2824
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002825- PyString_Size() and PyString_AsString() accept Unicode objects.
2826
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002827- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002828 exists). INT_MAX and LONG_MAX will always be defined, even if
2829 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002830
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002831- PyFloat_FromString takes a second argument, pend, that was
2832 effectively useless. It is now officially useless but preserved for
2833 backwards compatibility. If the pend argument is not NULL, *pend is
2834 set to NULL.
2835
2836- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2837 for the attribute name. See note on getattr() above.
2838
2839- A few bug fixes to argument processing for Unicode.
2840 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2841 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2842 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002843 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002844
2845- Py_BuildValue accepts B format (for bgen-generated code).
2846
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002847
Jeremy Hylton1b618592000-09-26 05:32:36 +00002848Internals
2849
2850- On Unix, fix code for finding Python installation directory so that
2851 it works when argv[0] is a relative path.
2852
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002853- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002854 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002855 rather than by generating a copy of the object.
2856
Tim Peters482c0212000-09-26 06:33:09 +00002857- Several of the internal Unicode tables are much smaller now, and
2858 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002859
Jeremy Hylton97693b02000-09-26 17:42:51 +00002860- In the garbage collector: Fixed bug in collection of tuples. Fixed
2861 bug that caused some instances to be removed from the container set
2862 while they were still live. Fixed parsing in gc.set_debug() for
2863 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002864
2865- Fixed refcount problem in instance deallocation that only occurred
2866 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2867
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002868- On Windows, getpythonregpath is now protected against null data in
2869 registry key.
2870
2871- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002872 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002873
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002874
Jeremy Hylton1b618592000-09-26 05:32:36 +00002875Build and platform-specific issues
2876
2877- Better support of GNU Pth via --with-pth configure option.
2878
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002879- Python/C API now properly exposed to dynamically-loaded extension
2880 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002881
2882- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2883 Don't define MS_SYNC to be zero when it is undefined. Added missing
2884 prototypes in posixmodule.c.
2885
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002886- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002887 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002888
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002889- Fix largefile support on older NetBSD systems and OpenBSD by adding
2890 define for TELL64.
2891
2892
2893Tools and other miscellany
2894
2895- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2896
2897- freeze: The modulefinder now works with 2.0 opcodes.
2898
Tim Petersa3a3a032000-11-30 05:22:44 +00002899- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002900 Move hackery of sys.argv until after the Tk instance has been
2901 created, which allows the application-specific Tkinter
2902 initialization to be executed if present; also pass an explicit
2903 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002904
Jeremy Hylton1b618592000-09-26 05:32:36 +00002905
2906What's new in 2.0 beta 1?
2907=========================
2908
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002909Source Incompatibilities
2910------------------------
2911
2912None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2913such as single-argument append(), connect() and bind(), and changes to
2914str(long) and repr(float).
2915
2916
2917Binary Incompatibilities
2918------------------------
2919
2920- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2921with Python 2.0; these extensions will have to be rebuilt for Python
29222.0.
2923
2924- On Windows, attempting to import a third party extension built for
2925Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2926can do about this. Check your PYTHONPATH environment variable!
2927
2928- Python bytecode files (*.pyc and *.pyo) are not compatible between
2929releases.
2930
2931
2932Overview of Changes Since 1.6
2933-----------------------------
2934
2935There are many new modules (including brand new XML support through
2936the xml package, and i18n support through the gettext module); a list
2937of all new modules is included below. Lots of bugs have been fixed.
2938
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002939The process for making major new changes to the language has changed
2940since Python 1.6. Enhancements must now be documented by a Python
2941Enhancement Proposal (PEP) before they can be accepted.
2942
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002943There are several important syntax enhancements, described in more
2944detail below:
2945
2946 - Augmented assignment, e.g. x += 1
2947
2948 - List comprehensions, e.g. [x**2 for x in range(10)]
2949
2950 - Extended import statement, e.g. import Module as Name
2951
2952 - Extended print statement, e.g. print >> file, "Hello"
2953
2954Other important changes:
2955
2956 - Optional collection of cyclical garbage
2957
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002958Python Enhancement Proposal (PEP)
2959---------------------------------
2960
2961PEP stands for Python Enhancement Proposal. A PEP is a design
2962document providing information to the Python community, or describing
2963a new feature for Python. The PEP should provide a concise technical
2964specification of the feature and a rationale for the feature.
2965
2966We intend PEPs to be the primary mechanisms for proposing new
2967features, for collecting community input on an issue, and for
2968documenting the design decisions that have gone into Python. The PEP
2969author is responsible for building consensus within the community and
2970documenting dissenting opinions.
2971
2972The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002973
2974Augmented Assignment
2975--------------------
2976
2977This must have been the most-requested feature of the past years!
2978Eleven new assignment operators were added:
2979
Guido van Rossume905e952000-09-05 12:42:46 +00002980 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002981
2982For example,
2983
2984 A += B
2985
2986is similar to
2987
2988 A = A + B
2989
2990except that A is evaluated only once (relevant when A is something
2991like dict[index].attr).
2992
2993However, if A is a mutable object, A may be modified in place. Thus,
2994if A is a number or a string, A += B has the same effect as A = A+B
2995(except A is only evaluated once); but if a is a list, A += B has the
2996same effect as A.extend(B)!
2997
2998Classes and built-in object types can override the new operators in
2999order to implement the in-place behavior; the not-in-place behavior is
3000used automatically as a fallback when an object doesn't implement the
3001in-place behavior. For classes, the method name is derived from the
3002method name for the corresponding not-in-place operator by inserting
3003an 'i' in front of the name, e.g. __iadd__ implements in-place
3004__add__.
3005
3006Augmented assignment was implemented by Thomas Wouters.
3007
3008
3009List Comprehensions
3010-------------------
3011
3012This is a flexible new notation for lists whose elements are computed
3013from another list (or lists). The simplest form is:
3014
3015 [<expression> for <variable> in <sequence>]
3016
Guido van Rossum56db0952000-09-06 23:34:25 +00003017For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003018This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003019
3020You can also add a condition:
3021
3022 [<expression> for <variable> in <sequence> if <condition>]
3023
3024For example, [w for w in words if w == w.lower()] would yield the list
3025of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003026than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003027
3028You can also have nested for loops and more than one 'if' clause. For
3029example, here's a function that flattens a sequence of sequences::
3030
3031 def flatten(seq):
3032 return [x for subseq in seq for x in subseq]
3033
3034 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3035
3036This prints
3037
3038 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3039
3040List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003041Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003042
3043
3044Extended Import Statement
3045-------------------------
3046
3047Many people have asked for a way to import a module under a different
3048name. This can be accomplished like this:
3049
3050 import foo
3051 bar = foo
3052 del foo
3053
3054but this common idiom gets old quickly. A simple extension of the
3055import statement now allows this to be written as follows:
3056
3057 import foo as bar
3058
3059There's also a variant for 'from ... import':
3060
3061 from foo import bar as spam
3062
3063This also works with packages; e.g. you can write this:
3064
3065 import test.regrtest as regrtest
3066
3067Note that 'as' is not a new keyword -- it is recognized only in this
3068context (this is only possible because the syntax for the import
3069statement doesn't involve expressions).
3070
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003071Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003072
3073
3074Extended Print Statement
3075------------------------
3076
3077Easily the most controversial new feature, this extension to the print
3078statement adds an option to make the output go to a different file
3079than the default sys.stdout.
3080
3081For example, to write an error message to sys.stderr, you can now
3082write:
3083
3084 print >> sys.stderr, "Error: bad dog!"
3085
3086As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003087evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003088
3089 print >> None, "Hello world"
3090
3091is equivalent to
3092
3093 print "Hello world"
3094
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003095Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003096
3097
3098Optional Collection of Cyclical Garbage
3099---------------------------------------
3100
3101Python is now equipped with a garbage collector that can hunt down
3102cyclical references between Python objects. It's no replacement for
3103reference counting; in fact, it depends on the reference counts being
3104correct, and decides that a set of objects belong to a cycle if all
3105their reference counts can be accounted for from their references to
3106each other. This devious scheme was first proposed by Eric Tiedemann,
3107and brought to implementation by Neil Schemenauer.
3108
3109There's a module "gc" that lets you control some parameters of the
3110garbage collection. There's also an option to the configure script
3111that lets you enable or disable the garbage collection. In 2.0b1,
3112it's on by default, so that we (hopefully) can collect decent user
3113experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003114performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003115off by default in the final 2.0 release.
3116
3117
3118Smaller Changes
3119---------------
3120
3121A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3122map(None, seq1, seq2, ...) when the sequences have the same length;
3123i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3124the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003125zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003126
3127sys.version_info is a tuple (major, minor, micro, level, serial).
3128
3129Dictionaries have an odd new method, setdefault(key, default).
3130dict.setdefault(key, default) returns dict[key] if it exists; if not,
3131it sets dict[key] to default and returns that value. Thus:
3132
3133 dict.setdefault(key, []).append(item)
3134
3135does the same work as this common idiom:
3136
3137 if not dict.has_key(key):
3138 dict[key] = []
3139 dict[key].append(item)
3140
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003141There are two new variants of SyntaxError that are raised for
3142indentation-related errors: IndentationError and TabError.
3143
3144Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3145escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003146
3147The limits on the size of expressions and file in Python source code
3148have been raised from 2**16 to 2**32. Previous versions of Python
3149were limited because the maximum argument size the Python VM accepted
3150was 2**16. This limited the size of object constructor expressions,
3151e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3152limit was raised thanks to a patch by Charles Waldman that effectively
3153fixes the problem. It is now much more likely that you will be
3154limited by available memory than by an arbitrary limit in Python.
3155
3156The interpreter's maximum recursion depth can be modified by Python
3157programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3158limit is the maximum number of recursive calls that can be made by
3159Python code. The limit exists to prevent infinite recursion from
3160overflowing the C stack and causing a core dump. The default value is
31611000. The maximum safe value for a particular platform can be found
3162by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003163
3164New Modules and Packages
3165------------------------
3166
3167atexit - for registering functions to be called when Python exits.
3168
3169imputil - Greg Stein's alternative API for writing custom import
3170hooks.
3171
3172pyexpat - an interface to the Expat XML parser, contributed by Paul
3173Prescod.
3174
3175xml - a new package with XML support code organized (so far) in three
3176subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3177would fill a volume. There's a special feature whereby a
3178user-installed package named _xmlplus overrides the standard
3179xmlpackage; this is intended to give the XML SIG a hook to distribute
3180backwards-compatible updates to the standard xml package.
3181
3182webbrowser - a platform-independent API to launch a web browser.
3183
3184
Guido van Rossume905e952000-09-05 12:42:46 +00003185Changed Modules
3186---------------
3187
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003188array -- new methods for array objects: count, extend, index, pop, and
3189remove
3190
3191binascii -- new functions b2a_hex and a2b_hex that convert between
3192binary data and its hex representation
3193
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003194calendar -- Many new functions that support features including control
3195over which day of the week is the first day, returning strings instead
3196of printing them. Also new symbolic constants for days of week,
3197e.g. MONDAY, ..., SUNDAY.
3198
3199cgi -- FieldStorage objects have a getvalue method that works like a
3200dictionary's get method and returns the value attribute of the object.
3201
3202ConfigParser -- The parser object has new methods has_option,
3203remove_section, remove_option, set, and write. They allow the module
3204to be used for writing config files as well as reading them.
3205
3206ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003207optionally support the RFC 959 REST command.
3208
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003209gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003210
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003211httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3212the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003213
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003214locale -- implement getdefaultlocale for Win32 and Macintosh
3215
3216marshal -- no longer dumps core when marshaling deeply nested or
3217recursive data structures
3218
3219os -- new functions isatty, seteuid, setegid, setreuid, setregid
3220
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003221os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3222support under Unix.
3223
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003224os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003225
3226os.path -- fix semantics of os.path.commonprefix
3227
3228smtplib -- support for sending very long messages
3229
3230socket -- new function getfqdn()
3231
3232readline -- new functions to read, write and truncate history files.
3233The readline section of the library reference manual contains an
3234example.
3235
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003236select -- add interface to poll system call
3237
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003238shutil -- new copyfileobj function
3239
3240SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3241HTTP server.
3242
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003243Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003244
3245urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003246e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003247
3248whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003249
3250
3251Obsolete Modules
3252----------------
3253
3254None. However note that 1.6 made a whole slew of modules obsolete:
3255stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3256poly, zmod, strop, util, whatsound.
3257
3258
3259Changed, New, Obsolete Tools
3260----------------------------
3261
Tim Peters8b092332000-09-05 20:15:25 +00003262None.
Guido van Rossume905e952000-09-05 12:42:46 +00003263
3264
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003265C-level Changes
3266---------------
3267
3268Several cleanup jobs were carried out throughout the source code.
3269
3270All C code was converted to ANSI C; we got rid of all uses of the
3271Py_PROTO() macro, which makes the header files a lot more readable.
3272
3273Most of the portability hacks were moved to a new header file,
3274pyport.h; several other new header files were added and some old
3275header files were removed, in an attempt to create a more rational set
3276of header files. (Few of these ever need to be included explicitly;
3277they are all included by Python.h.)
3278
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003279Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003280and Win64, especially for the new Intel Itanium processor. Mick also
3281added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003282
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003283The C APIs to return an object's size have been update to consistently
3284use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3285previous versions, the abstract interfaces used PyXXX_Length and the
3286concrete interfaces used PyXXX_Size. The old names,
3287e.g. PyObject_Length, are still available for backwards compatibility
3288at the API level, but are deprecated.
3289
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003290The PyOS_CheckStack function has been implemented on Windows by
3291Fredrik Lundh. It prevents Python from failing with a stack overflow
3292on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003293
3294The GC changes resulted in creation of two new slots on object,
3295tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003296the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003297
3298The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003299C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003300
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003301PyErr_Format has been updated to automatically calculate the size of
3302the buffer needed to hold the formatted result string. This change
3303prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003304
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003305New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003306
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003307PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3308that are the same as their non-Ex counterparts except they take an
3309extra flag argument that tells them to close the file when done.
3310
3311XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003312
Tim Peters8b092332000-09-05 20:15:25 +00003313
3314Windows Changes
3315---------------
3316
3317New popen2/popen3/peopen4 in os module (see Changed Modules above).
3318
3319os.popen is much more usable on Windows 95 and 98. See Microsoft
3320Knowledge Base article Q150956. The Win9x workaround described there
3321is implemented by the new w9xpopen.exe helper in the root of your
3322Python installation. Note that Python uses this internally; it is not
3323a standalone program.
3324
3325Administrator privileges are no longer required to install Python
3326on Windows NT or Windows 2000. If you have administrator privileges,
3327Python's registry info will be written under HKEY_LOCAL_MACHINE.
3328Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003329under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003330uses of Python, but will prevent some advanced uses from working
3331(for example, running a Python script as an NT service, or possibly
3332from CGI).
3333
3334[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3335installer; instead, it installs the needed Tcl/Tk files directly in the
3336Python directory. If you already have a Tcl/Tk installation, this
3337wastes some disk space (about 4 Megs) but avoids problems with
3338conflicting Tcl/Tk installations, and makes it much easier for Python
3339to ensure that Tcl/Tk can find all its files.
3340
3341[This was new in 1.6] The Windows installer now installs by default in
3342\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3343
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003344
3345Updates to the changes between 1.5.2 and 1.6
3346--------------------------------------------
3347
3348The 1.6 NEWS file can't be changed after the release is done, so here
3349is some late-breaking news:
3350
3351New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3352and changes to getlocale() and setlocale().
3353
3354The new module is now enabled per default.
3355
3356It is not true that the encodings codecs cannot be used for normal
3357strings: the string.encode() (which is also present on 8-bit strings
3358!) allows using them for 8-bit strings too, e.g. to convert files from
3359cp1252 (Windows) to latin-1 or vice-versa.
3360
3361Japanese codecs are available from Tamito KAJIYAMA:
3362http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3363
3364
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003365======================================================================