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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 Rossum95b62a62002-03-29 01:07:24 +00009- Fixed two bugs reported as SF #535905: under certain conditions,
10 deallocating a deeply nested structure could cause a segfault in the
11 garbage collector, due to interaction with the "trashcan" code;
12 access to the current frame during destruction of a local variable
13 could access a pointer to freed memory.
14
Neil Schemenauer9d50d132002-03-22 17:06:59 +000015- The optional object allocator has been enabled by default.
16
Guido van Rossum8c842552002-03-14 23:05:54 +000017- If you try to pickle an instance of a class that has __slots__ but
18 doesn't define or override __getstate__, a TypeError is now raised.
19 This is done by adding a bozo __getstate__ to the class that always
20 raises TypeError. (Before, this would appear to be pickled, but the
21 state of the slots would be lost.)
22
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000023- PyErr_Display will provide file and line information for all exceptions
24 that have an attribute print_file_and_line, not just SyntaxErrors.
25
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000026- The UTF-8 codec will now encode and decode Unicode surrogates
27 correctly and without raising exceptions for unpaired ones.
28
Neal Norwitz649b7592002-01-01 19:07:13 +000029- file.xreadlines() now raises a ValueError if the file is closed:
30 Previously, an xreadlines object was returned which would raise
31 a ValueError when the xreadlines.next() method was called.
32
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000033- posix.killpg has been added where available.
34
Neal Norwitz0c766a02002-03-27 13:03:09 +000035- sys.exit() inadvertantly allowed more than one argument.
36 An exception will now be raised if more than one argument is used.
37
Tim Petersaf8446f2001-12-21 21:36:50 +000038Extension modules
39
Martin v. Löwis2e64c342002-03-27 18:49:02 +000040- The locale module now exposes the C library's gettext interface.
41
Tim Petersfbf74f22002-03-14 19:06:01 +000042- A security hole ("double free") was found in zlib-1.1.3, a popular
43 third party compression library used by some Python modules. The
44 hole was quickly plugged in zlib-1.1.4, and the Windows build of
45 Python now ships with zlib-1.1.4.
46
Martin v. Löwis29001ff2002-03-01 10:47:37 +000047- pwd and grp return enhanced tuples now, with symbolic field names.
48
Martin v. Löwis99866332002-03-01 10:27:01 +000049- array.array is now a type object. A new format character
50 'u' indicates Py_UNICODE arrays. For those, .tounicode and
51 .fromunicode methods are available. Arrays now support __iadd__
52 and __imul__.
53
Neal Norwitze790eae2002-01-01 21:14:12 +000054- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000055 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
56 is called.
57
Tim Petersaf8446f2001-12-21 21:36:50 +000058Library
59
Martin v. Löwis5c137c22002-03-18 12:44:08 +000060- compileall now supports quiet operation.
61
Martin v. Löwis587c98c2002-03-17 18:37:22 +000062- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
63 connections.
64
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000065- socket module: the SSL support was broken out of the main
66 _socket module C helper and placed into a new _ssl helper
67 which now gets imported by socket.py if available and working.
68
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000069- encodings package: added aliases for all supported IANA character
70 sets
71
Guido van Rossum606fe4e2001-12-28 20:57:14 +000072- ftplib: to safeguard the user's privacy, anonymous login will use
73 "anonymous@" as default password, rather than the real user and host
74 name.
75
Fred Drake36736122002-01-10 13:50:31 +000076- webbrowser: tightened up the command passed to os.system() so that
77 arbitrary shell code can't be executed because a bogus URL was
78 passed in.
79
Tim Peters11bd9942002-02-01 00:52:29 +000080- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000081 gettext.find an optional all argument. Translations will now fallback
82 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000083
Martin v. Löwis9668b932002-01-12 11:27:42 +000084- distutils bdist commands now offer a --skip-build option.
85
Walter Dörwaldb25c2b02002-03-21 10:38:40 +000086- warnings.warn now accepts a Warning instance as first argument.
87
Tim Petersaf8446f2001-12-21 21:36:50 +000088Tools/Demos
89
90Build
91
92C API
93
Neil Schemenauer9d50d132002-03-22 17:06:59 +000094- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
95 functions will be allocated using pymalloc if it is enabled. These
96 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
97 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
98 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
99 PyCore_* family of APIs have been removed.
100
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000101- The "u#" parser marker will now pass through Unicode object as-is
102 without going through the buffer API.
103
Martin v. Löwis7198a522002-01-01 19:59:11 +0000104- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
105
Tim Peters10a3bb52001-12-25 19:07:38 +0000106- An old #define of ANY as void has been removed from pyport.h. This
107 hasn't been used since Python's pre-ANSI days, and the #define has
108 been marked as obsolete since then. SF bug 495548 says it created
109 conflicts with other packages, so keeping it around wasn't harmless.
110
Tim Petersaf8446f2001-12-21 21:36:50 +0000111- Because Python's magic number scheme broke on January 1st, we decided
112 to stop Python development. Thanks for all the fish!
113
Tim Petersfb05db22002-03-11 00:24:00 +0000114- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000115 scheme to a new one. See Python/import.c for details.
116
Tim Petersaf8446f2001-12-21 21:36:50 +0000117New platforms
118
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000119- GNU/Hurd is now supported.
120
Tim Petersaf8446f2001-12-21 21:36:50 +0000121Tests
122
123Windows
124
Tim Petersfb05db22002-03-11 00:24:00 +0000125- file.truncate([newsize]) now works on Windows for all newsize values.
126 It used to fail if newsize didn't fit in 32 bits, reflecting a
127 limitation of MS _chsize (which is no longer used).
128
Tim Petersab034fa2002-02-01 11:27:43 +0000129- os.waitpid() is now implemented for Windows, and can be used to block
130 until a specified process exits. This is similar to, but not exactly
131 the same as, os.waitpid() on POSIX systems. If you're waiting for
132 a specific process whose pid was obtained from one of the spawn()
133 functions, the same Python os.waitpid() code works across platforms.
134 See the docs for details.
135
Tim Peters11bd9942002-02-01 00:52:29 +0000136- New tempfile.TemporaryFile implementation for Windows: this doesn't
137 need a TemproraryFileWrapper wrapper anymore, and should be immune
138 to a nasty problem: before 2.3, if you got a temp file on Windows, it
139 got wrapped in an object whose close() method first closed the
140 underlying file, then deleted the file. This usually worked fine.
141 However, the spawn family of functions on Windows create (at a low C
142 level) the same set of open files in the spawned process Q as were
143 open in the spawning process P. If a temp file f was among them, then
144 doing f.close() in P first closed P's C-level file handle on f, but Q's
145 C-level file handle on f remained open, so the attempt in P to delete f
146 blew up with a "Permission denied" error (Windows doesn't allow
147 deleting open files). This was surprising, subtle, and difficult to
148 work around.
149
150- The os module now exports all the symbolic constants usable with the
151 low-level os.open() on Windows: the new constants in 2.3 are
152 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
153 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
154 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
155 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
156 (so specify both if you want both; note that neither is useful unless
157 specified with O_CREAT too).
158
Tim Petersaf8446f2001-12-21 21:36:50 +0000159Mac
160
161
Tim Peters909c0912001-12-14 23:16:18 +0000162What's New in Python 2.2 final?
163Release date: 21-Dec-2001
164===============================
165
166Type/class unification and new-style classes
167
Barry Warsaw52acb492001-12-21 20:04:22 +0000168- pickle.py, cPickle: allow pickling instances of new-style classes
169 with a custom metaclass.
170
Tim Peters909c0912001-12-14 23:16:18 +0000171Core and builtins
172
Barry Warsaw52acb492001-12-21 20:04:22 +0000173- weakref proxy object: when comparing, unwrap both arguments if both
174 are proxies.
175
Tim Peters909c0912001-12-14 23:16:18 +0000176Extension modules
177
Barry Warsaw52acb492001-12-21 20:04:22 +0000178- binascii.b2a_base64(): fix a potential buffer overrun when encoding
179 very short strings.
180
181- cPickle: the obscure "fast" mode was suspected of causing stack
182 overflows on the Mac. Hopefully fixed this by setting the recursion
183 limit much smaller. If the limit is too low (it only affects
184 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
185 when compiling cPickle.c (or in pyconfig.h).
186
Tim Peters909c0912001-12-14 23:16:18 +0000187Library
188
Barry Warsaw52acb492001-12-21 20:04:22 +0000189- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
190 close or delete time).
191
192- rfc822.py: fixed a bug where the address '<>' was converted to None
193 instead of an empty string (also fixes the email.Utils module).
194
195- xmlrpclib.py: version 1.0.0; uses precision for doubles.
196
197- test suite: the pickle and cPickle tests were not executing any code
198 when run from the standard regresssion test.
199
Tim Peters909c0912001-12-14 23:16:18 +0000200Tools/Demos
201
202Build
203
204C API
205
206New platforms
207
208Tests
209
210Windows
211
Barry Warsaw52acb492001-12-21 20:04:22 +0000212- distutils package: fixed broken Windows installers (bdist_wininst).
213
214- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
215 instances are deleted at process exit time.
216
217- socket.py: prevent mysterious warnings when socket instances are
218 deleted at process exit time.
219
220- posixmodule.c: fix a Windows crash with stat() of a filename ending
221 in backslash.
222
Tim Peters909c0912001-12-14 23:16:18 +0000223Mac
224
Barry Warsaw52acb492001-12-21 20:04:22 +0000225- The Carbon toolbox modules have been upgraded to Universal Headers
226 3.4, and experimental CoreGraphics and CarbonEvents modules have
227 been added. All only for framework-enabled MacOSX.
228
Tim Peters909c0912001-12-14 23:16:18 +0000229
Tim Peters6272dfd2001-12-13 19:34:00 +0000230What's New in Python 2.2c1?
231Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000232===========================
233
234Type/class unification and new-style classes
235
Barry Warsaw06557452001-12-14 20:47:12 +0000236- Guido's tutorial introduction to the new type/class features has
237 been extensively updated. See
238
239 http://www.python.org/2.2/descrintro.html
240
241 That remains the primary documentation in this area.
242
Guido van Rossum33bab012001-12-05 22:45:48 +0000243- Fixed a leak: instance variables declared with __slots__ were never
244 deleted!
245
Guido van Rossum4b800852001-12-03 00:54:52 +0000246- The "delete attribute" method of descriptor objects is called
247 __delete__, not __del__. In previous releases, it was mistakenly
248 called __del__, which created an unfortunate overloading condition
249 with finalizers. (The "get attribute" and "set attribute" methods
250 are still called __get__ and __set__, respectively.)
251
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000252- Some subtle issues with the super built-in were fixed:
253
254 (a) When super itself is subclassed, its __get__ method would still
255 return an instance of the base class (i.e., of super).
256
257 (b) super(C, C()).__class__ would return C rather than super. This
258 is confusing. To fix this, I decided to change the semantics of
259 super so that it only applies to code attributes, not to data
260 attributes. After all, overriding data attributes is not
261 supported anyway.
262
263 (c) The __get__ method didn't check whether the argument was an
264 instance of the type used in creation of the super instance.
265
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000266- Previously, hash() of an instance of a subclass of a mutable type
267 (list or dictionary) would return some value, rather than raising
268 TypeError. This has been fixed. Also, directly calling
269 dict.__hash__ and list.__hash__ now raises the same TypeError
270 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000271
Guido van Rossumd331cb52001-12-05 19:46:42 +0000272- New-style objects now support deleting their __dict__. This is for
273 all intents and purposes equivalent to assigning a brand new empty
274 dictionary, but saves space if the object is not used further.
275
Tim Petersb3c9af12001-11-17 00:21:57 +0000276Core and builtins
277
Tim Peters3caca232001-12-06 06:23:26 +0000278- -Qnew now works as documented in PEP 238: when -Qnew is passed on
279 the command line, all occurrences of "/" use true division instead
280 of classic division. See the PEP for details. Note that "all"
281 means all instances in library and 3rd-party modules, as well as in
282 your own code. As the PEP says, -Qnew is intended for use only in
283 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000284 Note that test_coercion.py in the standard Python test suite fails
285 under -Qnew; this is expected, and won't be repaired until true
286 division becomes the default (in the meantime, test_coercion is
287 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000288
Fred Drake6c01e252001-12-14 17:08:12 +0000289- complex() now only allows the first argument to be a string
290 argument, and raises TypeError if either the second arg is a string
291 or if the second arg is specified when the first is a string.
292
Tim Petersb3c9af12001-11-17 00:21:57 +0000293Extension modules
294
Martin v. Löwis560da622001-11-24 09:24:51 +0000295- gc.get_referents was renamed to gc.get_referrers.
296
Tim Petersb3c9af12001-11-17 00:21:57 +0000297Library
298
Tim Peters25059d32001-12-07 20:35:43 +0000299- Functions in the os.spawn() family now release the global interpreter
300 lock around calling the platform spawn. They should always have done
301 this, but did not before 2.2c1. Multithreaded programs calling
302 an os.spawn function with P_WAIT will no longer block all Python threads
303 until the spawned program completes. It's possible that some programs
304 relies on blocking, although more likely by accident than by design.
305
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000306- webbrowser defaults to netscape.exe on OS/2 now.
307
Martin v. Löwis652e1912001-11-25 14:50:56 +0000308- Tix.ResizeHandle exposes detach_widget, hide, and show.
309
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000310- The charset alias windows_1252 has been added.
311
Barry Warsaw06557452001-12-14 20:47:12 +0000312- types.StringTypes is a tuple containing the defined string types;
313 usually this will be (str, unicode), but if Python was compiled
314 without Unicode support it will be just (str,).
315
316- The pulldom and minidom modules were synchronized to PyXML.
317
Tim Petersb3c9af12001-11-17 00:21:57 +0000318Tools/Demos
319
Barry Warsaw06557452001-12-14 20:47:12 +0000320- A new script called Tools/scripts/google.py was added, which fires
321 off a search on Google.
322
Tim Petersb3c9af12001-11-17 00:21:57 +0000323Build
324
Barry Warsaw06557452001-12-14 20:47:12 +0000325- Note that release builds of Python should arrange to define the
326 preprocessor symbol NDEBUG on the command line (or equivalent).
327 In the 2.2 pre-release series we tried to define this by magic in
328 Python.h instead, but it proved to cause problems for extension
329 authors. The Unix, Windows and Mac builds now all define NDEBUG in
330 release builds via cmdline (or equivalent) instead. Ports to
331 other platforms should do likewise.
332
Jack Jansen1999ef42001-12-06 21:47:20 +0000333- It is no longer necessary to use --with-suffix when building on a
334 case-insensitive file system (such as Mac OS X HFS+). In the build
335 directory an extension is used, but not in the installed python.
336
Tim Petersb3c9af12001-11-17 00:21:57 +0000337C API
338
Tim Petersf582b822001-12-11 18:51:08 +0000339- New function PyDict_MergeFromSeq2() exposes the builtin dict
340 constructor's logic for updating a dictionary from an iterable object
341 producing key-value pairs.
342
Tim Peterscffed4b2001-11-29 03:26:37 +0000343- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000344 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000345 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
346 dump core in some bad cases. This has been repaired. As a result,
347 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
348 previously went unchallenged.
349
Tim Petersb3c9af12001-11-17 00:21:57 +0000350New platforms
351
352Tests
353
354Windows
355
356Mac
357
Jack Jansenffa260f2001-12-06 21:14:00 +0000358- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
359 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000360
Barry Warsaw06557452001-12-14 20:47:12 +0000361- Changed logic for finding python home in Mac OS X framework Pythons.
362 Now sys.executable points to the executable again, in stead of to
363 the shared library. The latter is used only for locating the python
364 home.
365
366
Tim Peters84362bc2001-10-19 17:55:30 +0000367What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000368Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000369===========================
370
371Type/class unification and new-style classes
372
Guido van Rossum3d27df02001-11-15 20:27:54 +0000373- Multiple inheritance mixing new-style and classic classes in the
374 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000375
376 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000377 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000378
379 The MRO (method resolution order) for each base class is respected
380 according to its kind, but the MRO for the derived class is computed
381 using new-style MRO rules if any base clase is a new-style class.
382 This needs to be documented.
383
Tim Petersa427a2b2001-10-29 22:25:45 +0000384- The new builtin dictionary() constructor, and dictionary type, have
385 been renamed to dict. This reflects a decade of common usage.
386
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000387- dict() now accepts an iterable object producing 2-sequences. For
388 example, dict(d.items()) == d for any dictionary d. The argument,
389 and the elements of the argument, can be any iterable objects.
390
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000391- New-style classes can now have a __del__ method, which is called
392 when the instance is deleted (just like for classic classes).
393
Guido van Rossum12d955c2001-10-26 14:56:06 +0000394- Assignment to object.__dict__ is now possible, for objects that are
395 instances of new-style classes that have a __dict__ (unless the base
396 class forbids it).
397
Guido van Rossumc8e56452001-10-22 00:43:43 +0000398- Methods of built-in types now properly check for keyword arguments
399 (formerly these were silently ignored). The only built-in methods
400 that take keyword arguments are __call__, __init__ and __new__.
401
Guido van Rossum86443212001-10-27 22:28:54 +0000402- The socket function has been converted to a type; see below.
403
Tim Peters84362bc2001-10-19 17:55:30 +0000404Core and builtins
405
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000406- Assignment to __debug__ raises SyntaxError at compile-time. This
407 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000408 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000409
Guido van Rossum12d955c2001-10-26 14:56:06 +0000410- Clarified the error messages for unsupported operands to an operator
411 (like 1 + '').
412
Tim Peters84362bc2001-10-19 17:55:30 +0000413Extension modules
414
Tim Peters5ebfd362001-11-13 23:11:19 +0000415- mmap has a new keyword argument, "access", allowing a uniform way for
416 both Windows and Unix users to create read-only, write-through and
417 copy-on-write memory mappings. This was previously possible only on
418 Unix. A new keyword argument was required to support this in a
419 uniform way because the mmap() signuatures had diverged across
420 platforms. Thanks to Jay T Miller for repairing this!
421
Tim Peters169ded02001-11-03 19:57:21 +0000422- By default, the gc.garbage list now contains only those instances in
423 unreachable cycles that have __del__ methods; in 2.1 it contained all
424 instances in unreachable cycles. "Instances" here has been generalized
425 to include instances of both new-style and old-style classes.
426
Guido van Rossum12d955c2001-10-26 14:56:06 +0000427- The socket module defines a new method for socket objects,
428 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000429 send() until all data has been sent. Also, the socket function has
430 been converted to a subclassable type, like list and tuple (etc.)
431 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000432
433- Various bugfixes to the curses module. There is now a test suite
434 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000435
Guido van Rossum692adf12001-10-30 03:03:03 +0000436- binascii.b2a_base64 no longer places an arbitrary restriction of 57
437 bytes on its input.
438
Tim Peters84362bc2001-10-19 17:55:30 +0000439Library
440
Tim Peters5ebfd362001-11-13 23:11:19 +0000441- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000442 convenience function.
443
Tim Peters75335872001-11-03 19:35:43 +0000444- Symbolic group names in regular expressions must be unique. For
445 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
446 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000447 Python 2.2 detects this error at regexp compilation time;
448 previously, the error went undetected, and results were
449 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
450 pattern.subn() methods have been rewritten in C. Also, an
451 experimental function/method finditer() has been added, which works
452 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000453
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000454- Tix exposes more commands through the classes DirSelectBox,
455 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
456 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
457 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
458
Tim Peters98791af2001-10-23 01:59:54 +0000459- Traceback objects are now scanned by cyclic garbage collection, so
460 cycles created by casual use of sys.exc_info() no longer cause
461 permanent memory leaks (provided garbage collection is enabled).
462
Guido van Rossum49192142001-10-24 20:51:44 +0000463- os.extsep -- a new variable needed by the RISCOS support. It is the
464 separator used by extensions, and is '.' on all platforms except
465 RISCOS, where it is '/'. There is no need to use this variable
466 unless you have a masochistic desire to port your code to RISCOS.
467
Barry Warsaw012852b2001-11-16 16:17:27 +0000468- mimetypes.py has optional support for non-standard, but commonly
469 found types. guess_type() and guess_extension() now accept an
470 optional `strict' flag, defaulting to true, which controls whether
471 recognize non-standard types or not. A few non-standard types we
472 know about have been added. Also, when run as a script, there are
473 new -l and -e options.
474
475- statcache is now deprecated.
476
477- email.Utils.formatdate() now produces the preferred RFC 2822 style
478 dates with numeric timezones (it used to produce obsolete dates
479 hard coded to "GMT" timezone). An optional `localtime' flag is
480 added to produce dates in the local timezone, with daylight savings
481 time properly taken into account.
482
483- In pickle and cPickle, instead of masking errors in load() by
484 transforming them into SystemError, we let the original exception
485 propagate out. Also, implement support for __safe_for_unpickling__
486 in pickle, as it already was supported in cPickle.
487
Tim Peters84362bc2001-10-19 17:55:30 +0000488Tools/Demos
489
490Build
491
Barry Warsaw012852b2001-11-16 16:17:27 +0000492- The dbm module is built using libdb1 if available. The bsddb module
493 is built with libdb3 if available.
494
495- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
496
Tim Peters84362bc2001-10-19 17:55:30 +0000497C API
498
Tim Peters1fc240e2001-10-26 05:06:50 +0000499- New function PySequence_Fast_GET_SIZE() returns the size of a non-
500 NULL result from PySequence_Fast(), more quickly than calling
501 PySequence_Size().
502
Barry Warsaw012852b2001-11-16 16:17:27 +0000503- New argument unpacking function PyArg_UnpackTuple() added.
504
505- New functions PyObject_CallFunctionObjArgs() and
506 PyObject_CallMethodObjArgs() have been added to make it more
507 convenient and efficient to call functions and methods from C.
508
509- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
510 possible that this will propagate errors it didn't before.
511
512- New function PyObject_CheckReadBuffer(), which returns true if its
513 argument supports the single-segment readable buffer interface.
514
Tim Peters84362bc2001-10-19 17:55:30 +0000515New platforms
516
Guido van Rossum86443212001-10-27 22:28:54 +0000517- We've finally confirmed that this release builds on HP-UX 11.00,
518 *with* threads, and passes the test suite.
519
Tim Peters7a33d8b2001-11-05 02:51:07 +0000520- Thanks to a series of patches from Michael Muller, Python may build
521 again under OS/2 Visual Age C++.
522
Guido van Rossum49192142001-10-24 20:51:44 +0000523- Updated RISCOS port by Dietmar Schwertberger.
524
Tim Peters84362bc2001-10-19 17:55:30 +0000525Tests
526
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000527- Added a test script for the curses module. It isn't run automatically;
528 regrtest.py must be run with '-u curses' to enable it.
529
Tim Peters84362bc2001-10-19 17:55:30 +0000530Windows
531
Barry Warsaw012852b2001-11-16 16:17:27 +0000532Mac
533
534- PythonScript has been moved to unsupported and is slated to be
535 removed completely in the next release.
536
537- It should now be possible to build applets that work on both OS9 and
538 OSX.
539
540- The core is now linked with CoreServices not Carbon; as a side
541 result, default 8bit encoding on OSX is now ASCII.
542
543- Python should now build on OSX 10.1.1
544
Tim Peters84362bc2001-10-19 17:55:30 +0000545
Tim Petersabf925f2001-09-28 21:53:42 +0000546What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000547Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000548===========================
549
550Type/class unification and new-style classes
551
Guido van Rossum687ae002001-10-15 22:03:32 +0000552- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000553 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000554 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000555 remains: the __dict__ of a new-style class is a read-only proxy; you
556 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000557 __defined__ attribute of new-style types no longer exists, for lack
558 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000559 future a __cache__ may be resurrected with a similar function, if I
560 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000561
Tim Peters1c9ca872001-10-04 06:43:12 +0000562- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
563 always returned None, even when there was a class docstring).
564
565- doctest now finds and runs docstrings attached to new-style classes,
566 class methods, static methods, and properties.
567
Guido van Rossum9074ef62001-10-16 21:34:49 +0000568Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000569
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000570- A very subtle syntactical pitfall in list comprehensions was fixed.
571 For example: [a+b for a in 'abc', for b in 'def']. The comma in
572 this example is a mistake. Previously, this would silently let 'a'
573 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
574 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
575 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
576 Note that [a for a in <singleton>] is a convoluted way to say
577 [<singleton>] anyway, so it's not like any expressiveness is lost.
578
Guido van Rossum9074ef62001-10-16 21:34:49 +0000579- getattr(obj, name, default) now only catches AttributeError, as
580 documented, rather than returning the default value for all
581 exceptions (which could mask bugs in a __getattr__ hook, for
582 example).
583
Fred Drakecb7a6b52001-10-22 18:41:51 +0000584- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000585 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000586 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000587 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000588
Guido van Rossum1c486092001-10-19 02:05:35 +0000589- unicode(obj) now behaves more like str(obj), accepting arbitrary
590 objects, and calling a __unicode__ method if it exists.
591 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000592 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000593
Barry Warsawf6fb1712001-10-19 05:35:40 +0000594- isinstance() now allows any object as the first argument and a
595 class, a type or something with a __bases__ tuple attribute for the
596 second argument. The second argument may also be a tuple of a
597 class, type, or something with __bases__, in which case isinstance()
598 will return true if the first argument is an instance of any of the
599 things contained in the second argument tuple. E.g.
600
601 isinstance(x, (A, B))
602
603 returns true if x is an instance of A or B.
604
Guido van Rossum9074ef62001-10-16 21:34:49 +0000605Extension modules
606
607- thread.start_new_thread() now returns the thread ID (previously None).
608
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000609- binascii has now two quopri support functions, a2b_qp and b2a_qp.
610
Guido van Rossumc524d952001-10-19 01:31:59 +0000611- readline now supports setting the startup_hook and the
612 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000613
Guido van Rossumc524d952001-10-19 01:31:59 +0000614- os and posix supports chroot(), setgroups() and unsetenv() where
615 available. The stat(), fstat(), statvfs() and fstatvfs() functions
616 now return "pseudo-sequences" -- the various fields can now be
617 accessed as attributes (e.g. os.stat("/").st_mtime) but for
618 backwards compatibility they also behave as a fixed-length sequence.
619 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000620 attributes.
621
622- time: localtime(), gmtime() and strptime() now return a
623 pseudo-sequence similar to the os.stat() return value, with
624 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000625
Guido van Rossum9074ef62001-10-16 21:34:49 +0000626- Decompression objects in the zlib module now accept an optional
627 second parameter to decompress() that specifies the maximum amount
628 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000629
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000630- optional SSL support in the socket module now exports OpenSSL
631 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
632 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000633 automatically seed its PRNG. Also, the keyfile and certfile
634 arguments to socket.ssl() are now optional.
635
636- posixmodule (and by extension, the os module on POSIX platforms) now
637 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000638
Guido van Rossum9074ef62001-10-16 21:34:49 +0000639Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000640
Tim Peters7402f792001-10-02 03:53:41 +0000641- doctest now excludes functions and classes not defined by the module
642 being tested, thanks to Tim Hochberg.
643
Fred Drakecb7a6b52001-10-22 18:41:51 +0000644- HotShot, a new profiler implemented using a C-based callback, has
645 been added. This substantially reduces the overhead of profiling,
646 but it is still quite preliminary. Support modules and
647 documentation will be added in upcoming releases (before 2.2 final).
648
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000649- profile now produces correct output in situations where an exception
650 raised in Python is cleared by C code (e.g. hasattr()). This used
651 to cause wrong output, including spurious claims of recursive
652 functions and attribution of time spent to the wrong function.
653
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000654 The code and documentation for the derived OldProfile and HotProfile
655 profiling classes was removed. The code hasn't worked for years (if
656 you tried to use them, they raised exceptions). OldProfile
657 intended to reproduce the behavior of the profiler Python used more
658 than 7 years ago, and isn't interesting anymore. HotProfile intended
659 to provide a faster profiler (but producing less information), and
660 that's a worthy goal we intend to meet via a different approach (but
661 without losing information).
662
Tim Peterscce092d2001-10-09 05:31:56 +0000663- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000664 a much better system-specific calibration constant. The constant can
665 now be specified in an instance constructor, or as a Profile class or
666 instance variable, instead of by editing profile.py's source code.
667 Calibration must still be done manually (see the docs for the profile
668 module).
669
670 Note that Profile.calibrate() must be overriden by subclasses.
671 Improving the accuracy required exploiting detailed knowledge of
672 profiler internals; the earlier method abstracted away the details
673 and measured a simplified model instead, but consequently computed
674 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000675
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000676- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000677 which indicates whether output is intended for the header 'Q'
678 encoding.
679
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000680- The SocketServer.ThreadingMixIn class now closes the request after
681 finish_request() returns. (Not when it errors out though.)
682
Barry Warsawf6fb1712001-10-19 05:35:40 +0000683- The nntplib module's NNTP.body() method has grown a `file' argument
684 to allow saving the message body to a file.
685
686- The email package has added a class email.Parser.HeaderParser which
687 only parses headers and does not recurse into the message's body.
688 Also, the module/class MIMEAudio has been added for representing
689 audio data (contributed by Anthony Baxter).
690
691- ftplib should be able to handle files > 2GB.
692
693- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
694 ON, and OFF.
695
Fred Drakecb7a6b52001-10-22 18:41:51 +0000696- xml.dom.minidom NodeList objects now support the length attribute
697 and item() method as required by the DOM specifications.
698
Guido van Rossumed554f62001-10-02 23:15:37 +0000699Tools/Demos
700
701- Demo/dns was removed. It no longer serves any purpose; a package
702 derived from it is now maintained by Anthony Baxter, see
703 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000704
Barry Warsawf6fb1712001-10-19 05:35:40 +0000705- The freeze tool has been made more robust, and two new options have
706 been added: -X and -E.
707
Tim Petersabf925f2001-09-28 21:53:42 +0000708Build
709
Barry Warsawf6fb1712001-10-19 05:35:40 +0000710- configure will use CXX in LINKCC if CXX is used to build main() and
711 the system requires to link a C++ main using the C++ compiler.
712
Tim Petersabf925f2001-09-28 21:53:42 +0000713C API
714
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000715- The documentation for the tp_compare slot is updated to require that
716 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
717 not correct. This is not yet enforced but will be enforced in
718 Python 2.3; even later, we may use -2 to indicate errors and +2 for
719 "NotImplemented". Right now, -1 should be used for an error return.
720
Tim Petersd38b1c72001-09-30 05:09:37 +0000721- PyLong_AsLongLong() now accepts int (as well as long) arguments.
722 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
723 as long) arguments.
724
Guido van Rossum3c288632001-10-16 21:13:49 +0000725- PyThread_start_new_thread() now returns a long int giving the thread
726 ID, if one can be calculated; it returns -1 for error, 0 if no
727 thread ID is calculated (this is an incompatible change, but only
728 the thread module used this API). This code has only really been
729 tested on Linux and Windows; other platforms please beware (and
730 report any bugs or strange behavior).
731
Guido van Rossum1c486092001-10-19 02:05:35 +0000732- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
733 input.
734
Tim Petersabf925f2001-09-28 21:53:42 +0000735New platforms
736
737Tests
738
739Windows
740
Tim Peters04cf1d32001-10-09 22:39:40 +0000741- Installer: If you install IDLE, and don't disable file-extension
742 registration, a new "Edit with IDLE" context (right-click) menu entry
743 is created for .py and .pyw files.
744
Tim Peters1ce3cf72001-10-01 17:58:40 +0000745- The signal module now supports SIGBREAK on Windows, thanks to Steven
746 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
747 action remains to call Win32 ExitProcess(). This can be changed via
748 signal.signal(). For example:
749
750 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
751 # (SIGINT) behavior.
752 import signal
753 signal.signal(signal.SIGBREAK,
754 signal.default_int_handler)
755
756 try:
757 while 1:
758 pass
759 except KeyboardInterrupt:
760 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
761 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
762 # program without the possibility for any Python-level cleanup).
763 print "Clean exit"
764
Tim Petersabf925f2001-09-28 21:53:42 +0000765
Tim Petersb07352e2001-09-08 01:25:47 +0000766What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000767Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000768===========================
769
Guido van Rossum808eea72001-09-25 04:15:41 +0000770Type/class unification and new-style classes
771
772- pydoc and inspect are now aware of new-style classes;
773 e.g. help(list) at the interactive prompt now shows proper
774 documentation for all operations on list objects.
775
776- Applications using Jim Fulton's ExtensionClass module can now safely
777 be used with Python 2.2. In particular, Zope 2.4.1 now works with
778 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
779 examples also work again. It is hoped that Gtk and Boost also work
780 with 2.2a4 and beyond. (If you can confirm this, please write
781 webmaster@python.org; if there are still problems, please open a bug
782 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000783
Tim Peters66c1a522001-09-24 21:17:50 +0000784- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
785 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
786 in the constructed property object. fget, fset and fdel weren't
787 discoverable from Python in 2.2a3. __doc__ is new, and allows to
788 associate a docstring with a property.
789
Guido van Rossum808eea72001-09-25 04:15:41 +0000790- Comparison overloading is now more completely implemented. For
791 example, a str subclass instance can properly be compared to a str
792 instance, and it can properly overload comparison. Ditto for most
793 other built-in object types.
794
795- The repr() of new-style classes has changed; instead of <type
796 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
797 *except* for built-in types, which are still rendered as <type
798 'Foo'> (to avoid upsetting existing code that might parse or
799 otherwise rely on repr() of certain type objects).
800
801- The repr() of new-style objects is now always <Foo object at XXX>;
802 previously, it was sometimes <Foo instance at XXX>.
803
804- For new-style classes, what was previously called __getattr__ is now
805 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000806 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000807 one in classic classes is defined which is called only if regular
808 attribute access raises AttributeError; to catch *all* attribute
809 access, you can use __getattribute__ (for new-style classes). If
810 both are defined, __getattribute__ is called first, and if it raises
811 AttributeError, __getattr__ is called.
812
813- The __class__ attribute of new-style objects can be assigned to.
814 The new class must have the same C-level object layout as the old
815 class.
816
817- The builtin file type can be subclassed now. In the usual pattern,
818 "file" is the name of the builtin type, and file() is a new builtin
819 constructor, with the same signature as the builtin open() function.
820 file() is now the preferred way to open a file.
821
822- Previously, __new__ would only see sequential arguments passed to
823 the type in a constructor call; __init__ would see both sequential
824 and keyword arguments. This made no sense whatsoever any more, so
825 now both __new__ and __init__ see all arguments.
826
827- Previously, hash() applied to an instance of a subclass of str or
828 unicode always returned 0. This has been repaired.
829
830- Previously, an operation on an instance of a subclass of an
831 immutable type (int, long, float, complex, tuple, str, unicode),
832 where the subtype didn't override the operation (and so the
833 operation was handled by the builtin type), could return that
834 instance instead a value of the base type. For example, if s was of
835 a str sublass type, s[:] returned s as-is. Now it returns a str
836 with the same value as s.
837
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000838- Provisional support for pickling new-style objects has been added.
839
Guido van Rossum808eea72001-09-25 04:15:41 +0000840Core
841
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000842- file.writelines() now accepts any iterable object producing strings.
843
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000844- PyUnicode_FromEncodedObject() now works very much like
845 PyObject_Str(obj) in that it tries to use __str__/tp_str
846 on the object if the object is not a string or buffer. This
847 makes unicode() behave like str() when applied to non-string/buffer
848 objects.
849
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000850- PyFile_WriteObject now passes Unicode objects to the file's write
851 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000852 of a print statement must support Unicode objects, i.e. they must
853 at least convert them into ASCII strings.
854
Guido van Rossum624c8af2001-09-18 15:21:04 +0000855- Thread scheduling on Solaris should be improved; it is no longer
856 necessary to insert a small sleep at the start of a thread in order
857 to let other runnable threads be scheduled.
858
Tim Petersb07352e2001-09-08 01:25:47 +0000859Library
860
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000861- StringIO.StringIO instances and cStringIO.StringIO instances support
862 read character buffer compatible objects for their .write() methods.
863 These objects are converted to strings and then handled as such
864 by the instances.
865
Barry Warsaw2f600732001-09-24 04:28:10 +0000866- The "email" package has been added. This is basically a port of the
867 mimelib package <http://sf.net/projects/mimelib> with API changes
868 and some implementations updated to use iterators and generators.
869
Tim Peters8a9c2842001-09-22 21:30:22 +0000870- difflib.ndiff() and difflib.Differ.compare() are generators now. This
871 restores the ability of Tools/scripts/ndiff.py to start producing output
872 before the entire comparison is complete.
873
Barry Warsaw58b072d2001-09-22 04:44:21 +0000874- StringIO.StringIO instances and cStringIO.StringIO instances support
875 iteration just like file objects (i.e. their .readline() method is
876 called for each iteration until it returns an empty string).
877
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000878- The codecs module has grown four new helper APIs to access
879 builtin codecs: getencoder(), getdecoder(), getreader(),
880 getwriter().
881
Guido van Rossum624c8af2001-09-18 15:21:04 +0000882- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
883 simplifies writing XML RPC servers.
884
Barry Warsaw647d5e82001-09-28 17:01:02 +0000885- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000886 after interpretation of symbolic links. On non-Unix systems, this
887 is an alias for os.path.abspath().
888
Tim Peters16a77ad2001-09-08 04:00:12 +0000889- operator.indexOf() (PySequence_Index() in the C API) now works with any
890 iterable object.
891
Guido van Rossum624c8af2001-09-18 15:21:04 +0000892- smtplib now supports various authentication and security features of
893 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000894
Guido van Rossum624c8af2001-09-18 15:21:04 +0000895- hmac: a new module implementing keyed hashing for message
896 authentication.
897
898- mimetypes now recognizes more extensions and file types. At the
899 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000900
Guido van Rossum624c8af2001-09-18 15:21:04 +0000901- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000902 Python 2.2 bytecode generation. It has also been promoted from a
903 Tool to a standard library package. (Tools/compiler still exists as
904 a sample driver.)
905
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000906Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000907
Tim Petersb07352e2001-09-08 01:25:47 +0000908Build
909
Guido van Rossum624c8af2001-09-18 15:21:04 +0000910- Large file support (LFS) is now automatic when the platform supports
911 it; no more manual configuration tweaks are needed. On Linux, at
912 least, it's possible to have a system whose C library supports large
913 files but whose kernel doesn't; in this case, large file support is
914 still enabled but doesn't do you any good unless you upgrade your
915 kernel or share your Python executable with another system whose
916 kernel has large file support.
917
918- The configure script now supplies plausible defaults in a
919 cross-compilation environment. This doesn't mean that the supplied
920 values are always correct, or that cross-compilation now works
921 flawlessly -- but it's a first step (and it shuts up most of
922 autoconf's warnings about AC_TRY_RUN).
923
924- The Unix build is now a bit less chatty, courtesy of the parser
925 generator. The build is completely silent (except for errors) when
926 using "make -s", thanks to a -q option to setup.py.
927
Tim Petersb07352e2001-09-08 01:25:47 +0000928C API
929
Guido van Rossum624c8af2001-09-18 15:21:04 +0000930- The "structmember" API now supports some new flag bits to deny read
931 and/or write access to attributes in restricted execution mode.
932
Tim Petersb07352e2001-09-08 01:25:47 +0000933New platforms
934
Guido van Rossum624c8af2001-09-18 15:21:04 +0000935- Compaq's iPAQ handheld, running the "familiar" Linux distribution
936 (http://familiar.handhelds.org).
937
Tim Petersb07352e2001-09-08 01:25:47 +0000938Tests
939
Tim Peters8a9c2842001-09-22 21:30:22 +0000940- The "classic" standard tests, which work by comparing stdout to
941 an expected-output file under Lib/test/output/, no longer stop at
942 the first mismatch. Instead the test is run to completion, and a
943 variant of ndiff-style comparison is used to report all differences.
944 This is much easier to understand than the previous style of reporting.
945
946- The unittest-based standard tests now use regrtest's test_main()
947 convention, instead of running as a side-effect of merely being
948 imported. This allows these tests to be run in more natural and
949 flexible ways as unittests, outside the regrtest framework.
950
951- regrtest.py is much better integrated with unittest and doctest now,
952 especially in regard to reporting errors.
953
Tim Petersb07352e2001-09-08 01:25:47 +0000954Windows
955
Guido van Rossum624c8af2001-09-18 15:21:04 +0000956- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000957 that support it (NTFS under Windows 2000). See "What's New in
958 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000959
Tim Petersb07352e2001-09-08 01:25:47 +0000960
Tim Petersedc99312001-08-22 21:36:50 +0000961What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000962Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000963===========================
964
965Core
966
Tim Peters9fffa3e2001-09-04 05:14:19 +0000967- Conversion of long to float now raises OverflowError if the long is too
968 big to represent as a C double.
969
Tim Peters32f453e2001-09-03 08:35:41 +0000970- The 3-argument builtin pow() no longer allows a third non-None argument
971 if either of the first two arguments is a float, or if both are of
972 integer types and the second argument is negative (in which latter case
973 the arguments are converted to float, so this is really the same
974 restriction).
975
Tim Peters5d2b77c2001-09-03 05:47:38 +0000976- The builtin dir() now returns more information, and sometimes much
977 more, generally naming all attributes of an object, and all attributes
978 reachable from the object via its class, and from its class's base
979 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
980 an empty list. In 2.2a3,
981
982 >>> dir([])
983 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
984 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
985 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
986 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
987 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
988 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
989 'reverse', 'sort']
990
991 dir(module) continues to return only the module's attributes, though.
992
Tim Petersbdee63f2001-09-02 03:40:59 +0000993- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000994 than raising OverflowError. This is a partial implementation of PEP
995 237. You can use -Wdefault::OverflowWarning to enable a warning for
996 this situation, and -Werror::OverflowWarning to revert to the old
997 OverflowError exception.
998
Guido van Rossum61c345f2001-09-04 03:26:15 +0000999- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001000 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001001 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1002 -Qold, meaning the / operator has its classic meaning and no
1003 warnings are issued. Using -Qwarn issues a run-time warning about
1004 all uses of classic division for int and long arguments; -Qwarnall
1005 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001006 (for use with fixdiv.py).
1007 [Note: the remainder of this paragraph (preserved below) became
1008 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1009 <obsolete>
1010 Using -Qnew is questionable; it turns on new division by default, but
1011 only in the __main__ module. You can usefully combine -Qwarn or
1012 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1013 warns about classic division everywhere else.
1014 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001015
Tim Petersbdee63f2001-09-02 03:40:59 +00001016- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001017 long, float, str, unicode, and tuple. (The types complex, list and
1018 dictionary can also be subclassed; this was introduced earlier.)
1019 Note that restrictions apply when subclassing immutable built-in
1020 types: you can only affect the value of the instance by overloading
1021 __new__. You can add mutable attributes, and the subclass instances
1022 will have a __dict__ attribute, but you cannot change the "value"
1023 (as implemented by the base class) of an immutable subclass instance
1024 once it is created.
1025
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001026- The dictionary constructor now takes an optional argument, a
1027 mapping-like object, and initializes the dictionary from its
1028 (key, value) pairs.
1029
Tim Petersbdee63f2001-09-02 03:40:59 +00001030- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001031 "cooperative super calls" in a multiple inheritance setting. For an
1032 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1033
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001034- A new built-in type, property, has been added. This enables the
1035 creation of "properties". These are attributes implemented by
1036 getter and setter functions (or only one of these for read-only or
1037 write-only attributes), without the need to override __getattr__.
1038 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001039
Tim Petersbdee63f2001-09-02 03:40:59 +00001040- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001041 liberalized, to allow leading zeroes. Examples of literals now
1042 legal that were SyntaxErrors before:
1043
1044 00.0 0e3 0100j 07.5 00000000000000000008.
1045
Tim Petersbdee63f2001-09-02 03:40:59 +00001046- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001047 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1048
Tim Petersedc99312001-08-22 21:36:50 +00001049Library
1050
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001051- telnetlib includes symbolic names for the options, and support for
1052 setting an option negotiation callback.
1053
Tim Petersa40c7932001-09-05 22:36:56 +00001054- The new C standard no longer requires that math libraries set errno to
1055 ERANGE on overflow. For platform libraries that exploit this new
1056 freedom, Python's overflow-checking was wholly broken. A new overflow-
1057 checking scheme attempts to repair that, but may not be reliable on all
1058 platforms (C doesn't seem to provide anything both useful and portable
1059 in this area anymore).
1060
Martin v. Löwis44f86962001-09-05 13:44:54 +00001061- Asynchronous timeout actions are available through the new class
1062 threading.Timer.
1063
Tim Peters78526162001-09-05 00:53:45 +00001064- math.log and math.log10 now return sensible results for even huge
1065 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1066
Tim Petersbdee63f2001-09-02 03:40:59 +00001067- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001068 currently held. See the docs for the imp module.
1069
Tim Petersbdee63f2001-09-02 03:40:59 +00001070- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001071 dumps containing ints written on platforms where Python ints are 8 bytes.
1072 When read on a box where Python ints are 4 bytes, such values are
1073 converted to Python longs.
1074
Tim Petersbdee63f2001-09-02 03:40:59 +00001075- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001076 code objects is no longer allowed. This plugs a security hole.
1077
Steve Purcell6091cd62001-09-06 16:05:17 +00001078- unittest.TestResult instances no longer store references to tracebacks
1079 generated by test failures. This prevents unexpected dangling references
1080 to objects that should be garbage collected between tests.
1081
Tim Petersedc99312001-08-22 21:36:50 +00001082Tools
1083
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001084- Tools/scripts/fixdiv.py has been added which can be used to fix
1085 division operators as per PEP 238.
1086
Tim Petersedc99312001-08-22 21:36:50 +00001087Build
1088
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001089- If you are an adventurous person using Mac OS X you may want to look at
1090 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1091 application, which can be used for experimenting with Carbon or Cocoa.
1092 Discussion of this on pythonmac-sig, please.
1093
Tim Peters7eea37e2001-09-04 22:08:56 +00001094C API
1095
1096- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001097
Tim Peters9fffa3e2001-09-04 05:14:19 +00001098- Note that PyLong_AsDouble can fail! This has always been true, but no
1099 callers checked for it. It's more likely to fail now, because overflow
1100 errors are properly detected now. The proper way to check:
1101
1102 double x = PyLong_AsDouble(some_long_object);
1103 if (x == -1.0 && PyErr_Occurred()) {
1104 /* The conversion failed. */
1105 }
1106
Tim Petersbdee63f2001-09-02 03:40:59 +00001107- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001108 compile but will not participate in GC. To upgrade an extension
1109 module:
1110
1111 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001112
Neil Schemenauer4042c692001-08-30 15:38:01 +00001113 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1114 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001115
Neil Schemenauer4042c692001-08-30 15:38:01 +00001116 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1117 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001118
Neil Schemenauer4042c692001-08-30 15:38:01 +00001119 - remove PyGC_HEAD_SIZE from object size calculations
1120
1121 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1122
Tim Petersbdee63f2001-09-02 03:40:59 +00001123- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001124 These can be used safely to construct string objects from a
1125 sprintf-style format string (similar to the format string supported
1126 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001127
Tim Petersedc99312001-08-22 21:36:50 +00001128New platforms
1129
Tim Petersb7da0902001-09-02 23:01:43 +00001130- Stephen Hansen contributed patches sufficient to get a clean compile
1131 under Borland C (Windows), but he reports problems running it and ran
1132 out of time to complete the port. Volunteers? Expect a MemoryError
1133 when importing the types module; this is probably shallow, and
1134 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001135
Tim Petersedc99312001-08-22 21:36:50 +00001136Tests
1137
1138Windows
1139
Tim Peters6e13a562001-09-06 00:32:15 +00001140- Large file support is now enabled on Win32 platforms as well as on
1141 Win64. This means that, for example, you can use f.tell() and f.seek()
1142 to manipulate files larger than 2 gigabytes (provided you have enough
1143 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001144 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1145 filesize limit, and large file support makes no difference there.
1146 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1147 NTFS has no practical limit on file size, and files of any size can be
1148 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001149
Tim Petersbdee63f2001-09-02 03:40:59 +00001150- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001151 points to command.com (patch from Brian Quinlan).
1152
Tim Petersedc99312001-08-22 21:36:50 +00001153
Tim Peters20f51a72001-07-21 02:31:40 +00001154What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001155Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001156===========================
1157
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001158Build
1159
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001160- Tim Peters developed a brand new Windows installer using Wise 8.1,
1161 generously donated to us by Wise Solutions.
1162
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001163- configure supports a new option --enable-unicode, with the values
1164 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1165 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001166
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001167- A new configure option --enable-framework builds a Mac OS X framework,
1168 which "make frameworkinstall" will install. This provides a starting
1169 point for more mac-like functionality, join pythonmac-sig@python.org
1170 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001171
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001172- The NeXT platform is no longer supported.
1173
1174- The `new' module is now statically linked.
1175
Tim Peters0afb6092001-08-15 06:06:44 +00001176Tools
1177
1178- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001179 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001180 the module docstring for details.
1181
Tim Peters20f51a72001-07-21 02:31:40 +00001182Tests
1183
Tim Peters5e824c32001-08-12 22:25:01 +00001184- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001185 platforms, allowing to give clearer test result output. regrtest
1186 also has optional --use/-u switch to run normally disabled tests
1187 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001188
Tim Peters20f51a72001-07-21 02:31:40 +00001189- Several new tests in the standard test suite, with special thanks to
1190 Nick Mathewson.
1191
1192Core
1193
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001194- The floor division operator // has been added as outlined in PEP
1195 238. The / operator still provides classic division (and will until
1196 Python 3.0) unless "from __future__ import division" is included, in
1197 which case the / operator will provide true division. The operator
1198 module provides truediv() and floordiv() functions. Augmented
1199 assignment variants are included, as are the equivalent overloadable
1200 methods and C API methods. See the PEP for a full discussion:
1201 <http://python.sf.net/peps/pep-0238.html>
1202
Tim Peters6cd6a822001-08-17 22:11:27 +00001203- Future statements are now effective in simulated interactive shells
1204 (like IDLE). This should "just work" by magic, but read Michael
1205 Hudson's "Future statements in simulated shells" PEP 264 for full
1206 details: <http://python.sf.net/peps/pep-0264.html>.
1207
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001208- The type/class unification (PEP 252-253) was integrated into the
1209 trunk and is not so tentative any more (the exact specification of
1210 some features is still tentative). A lot of work has done on fixing
1211 bugs and adding robustness and features (performance still has to
1212 come a long way).
1213
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001214- Warnings about a mismatch in the Python API during extension import
1215 now use the Python warning framework (which makes it possible to
1216 write filters for these warnings).
1217
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001218- A function's __dict__ (aka func_dict) will now always be a
1219 dictionary. It used to be possible to delete it or set it to None,
1220 but now both actions raise TypeErrors. It is still legal to set it
1221 to a dictionary object. Getting func.__dict__ before any attributes
1222 have been assigned now returns an empty dictionary instead of None.
1223
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001224- A new command line option, -E, was added which disables the use of
1225 all environment variables, or at least those that are specifically
1226 significant to Python. Usually those have a name starting with
1227 "PYTHON". This was used to fix a problem where the tests fail if
1228 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1229 older distribution.
1230
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001231Library
1232
Tim Peters5e824c32001-08-12 22:25:01 +00001233- New class Differ and new functions ndiff() and restore() in difflib.py.
1234 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001235 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001236
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001237- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1238 value using the minimal quoting required for the value; more
1239 reliable than using xml.sax.saxutils.escape() for attribute values.
1240
1241- Readline completion support for cmd.Cmd was added.
1242
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001243- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1244
1245- Added function threading.BoundedSemaphore()
1246
1247- Added Ka-Ping Yee's cgitb.py module.
1248
1249- The `new' module now exposes the CO_xxx flags.
1250
Martin v. Löwis560da622001-11-24 09:24:51 +00001251- The gc module offers the get_referents function.
1252
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001253New platforms
1254
1255C API
1256
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001257- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1258 which provide a cross-platform implementations for the
1259 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1260 the standard sprintf() and vsprintf() C lib APIs, these versions
1261 apply bounds checking on the used buffer which enhances protection
1262 against buffer overruns.
1263
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001264- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001265 and extensions using different Unicode widths is rendered next to
1266 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001267 will result in an ImportError. Unicode extensions writers must make
1268 sure to check the Unicode width compatibility in their extensions by
1269 using at least one of the mangled Unicode APIs in the extension.
1270
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001271- Two new flags METH_NOARGS and METH_O are available in method definition
1272 tables to simplify implementation of methods with no arguments and a
1273 single untyped argument. Calling such methods is more efficient than
1274 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1275 deprecated.
1276
Tim Petersc1731372001-08-04 08:12:36 +00001277Windows
1278
1279- "import module" now compiles module.pyw if it exists and nothing else
1280 relevant is found.
1281
Tim Peters20f51a72001-07-21 02:31:40 +00001282
Guido van Rossum55a78992001-07-17 17:22:32 +00001283What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001284Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001285===========================
1286
1287Core
Tim Petersa814db52001-05-14 07:05:58 +00001288
Tim Peters6d6c1a32001-08-02 04:15:00 +00001289- TENTATIVELY, a large amount of code implementing much of what's
1290 described in PEP 252 (Making Types Look More Like Classes) and PEP
1291 253 (Subtyping Built-in Types) was added. This will be released
1292 with Python 2.2a1. Documentation will be provided separately
1293 through http://www.python.org/2.2/. The purpose of releasing this
1294 with Python 2.2a1 is to test backwards compatibility. It is
1295 possible, though not likely, that a decision is made not to release
1296 this code as part of 2.2 final, if any serious backwards
1297 incompapatibilities are found during alpha testing that cannot be
1298 repaired.
1299
Guido van Rossum55a78992001-07-17 17:22:32 +00001300- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001301 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001302 more 'yield' statements. See PEP 255. Since this adds a new
1303 keyword to the language, this feature must be enabled by including a
1304 future statement: "from __future__ import generators" (see PEP 236).
1305 Generators will become a standard feature in a future release
1306 (probably 2.3). Without this future statement, 'yield' remains an
1307 ordinary identifier, but a warning is issued each time it is used.
1308 (These warnings currently don't conform to the warnings framework of
1309 PEP 230; we intend to fix this in 2.2a2.)
1310
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001311- The UTF-16 codec was modified to be more RFC compliant. It will now
1312 only remove BOM characters at the start of the string and then
1313 only if running in native mode (UTF-16-LE and -BE won't remove a
1314 leading BMO character).
1315
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001316- Strings now have a new method .decode() to complement the already
1317 existing .encode() method. These two methods provide direct access
1318 to the corresponding decoders and encoders of the registered codecs.
1319
1320 To enhance the usability of the .encode() method, the special
1321 casing of Unicode object return values was dropped (Unicode objects
1322 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001323
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001324 Both methods will now return whatever the codec in charge of the
1325 requested encoding returns as object, e.g. Unicode codecs will
1326 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1327 will return u"äöü"). This enables codec writer to create codecs
1328 for various simple to use conversions.
1329
1330 New codecs were added to demonstrate these new features (the .encode()
1331 and .decode() columns indicate the type of the returned objects):
1332
1333 Name | .encode() | .decode() | Description
1334 ----------------------------------------------------------------------
1335 uu | string | string | UU codec (e.g. for email)
1336 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001337 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001338 zlib | string | string | zlib compression
1339 hex | string | string | 2-byte hex codec
1340 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1341
Mark Hammond2a0af792001-05-14 03:09:36 +00001342- Some operating systems now support the concept of a default Unicode
1343 encoding for file system operations. Notably, Windows supports 'mbcs'
1344 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001345 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001346 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001347
1348 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001349 functions that return filenames (such as os.listdir()) to return Python
1350 string objects pre-encoded using the default file system encoding for
1351 the platform. As this encoding is likely to be different from Python's
1352 default encoding, converting this name to a Unicode object before passing
1353 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001354 would attempt to use its default encoding (generally ASCII) rather than
1355 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001356
Tim Petersa814db52001-05-14 07:05:58 +00001357 In general, this change simply removes surprises when working with
1358 Unicode and the file system, making these operations work as you expect,
1359 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001360 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001361
Tim Peters61dff2b2001-05-08 15:43:37 +00001362- Float (and complex) literals in source code were evaluated to full
1363 precision only when running from a .py file; the same code loaded from a
1364 .pyc (or .pyo) file could suffer numeric differences starting at about the
1365 12th significant decimal digit. For example, on a machine with IEEE-754
1366 floating arithmetic,
1367
1368 x = 9007199254740992.0
1369 print long(x)
1370
1371 printed 9007199254740992 if run directly from .py, but 9007199254740000
1372 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1373 str(float) instead of repr(float) when building code objects. marshal
1374 now uses repr(float) instead, which should reproduce floats to full
1375 machine precision (assuming the platform C float<->string I/O conversion
1376 functions are of good quality).
1377
1378 This may cause floating-point results to change in some cases, and
1379 usually for the better, but may also cause numerically unstable
1380 algorithms to break.
1381
Tim Peters2f228e72001-05-13 00:19:31 +00001382- The implementation of dicts suffers fewer collisions, which has speed
1383 benefits. However, the order in which dict entries appear in dict.keys(),
1384 dict.values() and dict.items() may differ from previous releases for a
1385 given dict. Nothing is defined about this order, so no program should
1386 rely on it. Nevertheless, it's easy to write test cases that rely on the
1387 order by accident, typically because of printing the str() or repr() of a
1388 dict to an "expected results" file. See Lib/test/test_support.py's new
1389 sortdict(dict) function for a simple way to display a dict in sorted
1390 order.
1391
Tim Peters7a3bfc32001-06-12 01:22:22 +00001392- Many other small changes to dicts were made, resulting in faster
1393 operation along the most common code paths.
1394
Guido van Rossum10315822001-05-01 20:54:30 +00001395- Dictionary objects now support the "in" operator: "x in dict" means
1396 the same as dict.has_key(x).
1397
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001398- The update() method of dictionaries now accepts generic mapping
1399 objects. Specifically the argument object must support the .keys()
1400 and __getitem__() methods. This allows you to say, for example,
1401 {}.update(UserDict())
1402
Guido van Rossum10315822001-05-01 20:54:30 +00001403- Iterators were added; this is a generalized way of providing values
1404 to a for loop. See PEP 234. There's a new built-in function iter()
1405 to return an iterator. There's a new protocol to get the next value
1406 from an iterator using the next() method (in Python) or the
1407 tp_iternext slot (in C). There's a new protocol to get iterators
1408 using the __iter__() method (in Python) or the tp_iter slot (in C).
1409 Iterating (i.e. a for loop) over a dictionary generates its keys.
1410 Iterating over a file generates its lines.
1411
Tim Petersf553f892001-05-01 20:45:31 +00001412- The following functions were generalized to work nicely with iterator
1413 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001414 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001415 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1416 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001417 join() method of strings
1418 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001419 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1420 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001421 right-hand side of assignment statements with multiple targets, such as
1422 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001423
Tim Petersd85e1022001-05-11 21:51:48 +00001424- Accessing module attributes is significantly faster (for example,
1425 random.random or os.path or yourPythonModule.yourAttribute).
1426
Tim Peterse63415e2001-05-08 04:38:29 +00001427- Comparing dictionary objects via == and != is faster, and now works even
1428 if the keys and values don't support comparisons other than ==.
1429
Tim Peters95bf9392001-05-10 08:32:44 +00001430- Comparing dictionaries in ways other than == and != is slower: there were
1431 insecurities in the dict comparison implementation that could cause Python
1432 to crash if the element comparison routines for the dict keys and/or
1433 values mutated the dicts. Making the code bulletproof slowed it down.
1434
Tim Peterseb28ef22001-06-02 05:27:19 +00001435- Collisions in dicts are resolved via a new approach, which can help
1436 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001437 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001438 faster now. Thanks to Christian Tismer for pointing out the cause and
1439 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001440
Tim Peters52e155e2001-06-16 05:42:57 +00001441- repr() is much faster for large containers (dict, list, tuple).
1442
1443
Tim Petersa814db52001-05-14 07:05:58 +00001444Library
1445
Fred Drake960fdf92001-07-20 18:38:26 +00001446- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1447 were added to the string module. These a locale-indenpendent
1448 constants, unlike letters, lowercase, and uppercase. These are now
1449 use in appropriate locations in the standard library.
1450
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001451- The flags used in dlopen calls can now be configured using
1452 sys.setdlopenflags and queried using sys.getdlopenflags.
1453
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001454- Fredrik Lundh's xmlrpclib is now a standard library module. This
1455 provides full client-side XML-RPC support. In addition,
1456 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1457 one asyncore-based). Thanks to Eric Raymond for the documentation.
1458
Guido van Rossum643d3912001-07-05 14:46:25 +00001459- The xrange() object is simplified: it no longer supports slicing,
1460 repetition, comparisons, efficient 'in' checking, the tolist()
1461 method, or the start, stop and step attributes. See PEP 260.
1462
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001463- A new function fnmatch.filter to filter lists of file names was added.
1464
Barry Warsawffd674d2001-05-22 16:00:10 +00001465- calendar.py uses month and day names based on the current locale.
1466
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001467- strop is now *really* obsolete (this was announced before with 1.6),
1468 and issues DeprecationWarning when used (except for the four items
1469 that are still imported into string.py).
1470
Tim Petersa814db52001-05-14 07:05:58 +00001471- Cookie.py now sorts key+value pairs by key in output strings.
1472
1473- pprint.isrecursive(object) didn't correctly identify recursive objects.
1474 Now it does.
1475
Tim Peters95b3f782001-05-14 18:39:41 +00001476- pprint functions now much faster for large containers (tuple, list, dict).
1477
Tim Peters7b9542a2001-06-10 23:40:19 +00001478- New 'q' and 'Q' format codes in the struct module, corresponding to C
1479 types "long long" and "unsigned long long" (on Windows, __int64). In
1480 native mode, these can be used only when the platform C compiler supports
1481 these types (when HAVE_LONG_LONG is #define'd by the Python config
1482 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001483 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1484 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001485
Guido van Rossum83213cc2001-06-12 16:48:52 +00001486- The site module installs a new built-in function 'help' that invokes
1487 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1488 it displays a message reminding the user to use 'help()' or
1489 'help(object)'.
1490
Tim Petersa814db52001-05-14 07:05:58 +00001491Tests
1492
1493- New test_mutants.py runs dict comparisons where the key and value
1494 comparison operators mutute the dicts randomly during comparison. This
1495 rapidly causes Python to crash under earlier releases (not for the faint
1496 of heart: it can also cause Win9x to freeze or reboot!).
1497
1498- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001499 pprint.isreadable() return sensible results. Also verifies that simple
1500 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001501
Tim Peters4324aa32001-05-28 22:30:08 +00001502C API
1503
1504- Removed the unused last_is_sticky argument from the internal
1505 _PyTuple_Resize(). If this affects you, you were cheating.
1506
1507
Guido van Rossum55a78992001-07-17 17:22:32 +00001508======================================================================
1509
1510
Guido van Rossumffe13be2001-04-16 18:46:45 +00001511What's New in Python 2.1 (final)?
1512=================================
1513
1514We only changed a few things since the last release candidate, all in
1515Python library code:
1516
1517- A bug in the locale module was fixed that affected locales which
1518 define no grouping for numeric formatting.
1519
1520- A few bugs in the weakref module's implementations of weak
1521 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1522 and the test suite was updated to check for these bugs.
1523
1524- An old bug in the os.path.walk() function (introduced in Python
1525 2.0!) was fixed: a non-existent file would cause an exception
1526 instead of being ignored.
1527
1528- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1529 PyChecker.
1530
1531
Guido van Rossum5b08f132001-04-16 02:05:23 +00001532What's New in Python 2.1c2?
1533===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001534
Guido van Rossum5b08f132001-04-16 02:05:23 +00001535A flurry of small changes, and one showstopper fixed in the nick of
1536time made it necessary to release another release candidate. The list
1537here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001538
Guido van Rossum5b08f132001-04-16 02:05:23 +00001539Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001540
Guido van Rossum5b08f132001-04-16 02:05:23 +00001541- Tim discovered a nasty bug in the dictionary code, caused by
1542 PyDict_Next() calling dict_resize(), and the GC code's use of
1543 PyDict_Next() violating an assumption in dict_items(). This was
1544 fixed with considerable amounts of band-aid, but the net effect is a
1545 saner and more robust implementation.
1546
1547- Made a bunch of symbols static that were accidentally global.
1548
1549Build and Ports
1550
1551- The setup.py script didn't check for a new enough version of zlib
1552 (1.1.3 is needed). Now it does.
1553
1554- Changed "make clean" target to also remove shared libraries.
1555
1556- Added a more general warning about the SGI Irix optimizer to README.
1557
1558Library
1559
1560- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1561 omitted the slash between host and file.html.
1562
1563- The mailbox module's _Mailbox class contained a completely broken
1564 and undocumented seek() method. Ripped it out.
1565
1566- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1567 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1568
1569- Fixed a few last-minute bugs in unittest.
1570
1571Extensions
1572
1573- Reverted the patch to the OpenSSL code in socketmodule.c to support
1574 RAND_status() and the EGD, and the subsequent patch that tried to
1575 fix it for pre-0.9.5 versions; the problem with the patch is that on
1576 some systems it issues a warning whenever socket is imported, and
1577 that's unacceptable.
1578
1579Tests
1580
1581- Fixed the pickle tests to work with "import test.test_pickle".
1582
1583- Tweaked test_locale.py to actually run the test Windows.
1584
1585- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1586 not "wb" (which is not a valid mode at all).
1587
1588- Fix pstats browser crashes. Import readline if it exists to make
1589 the user interface nicer.
1590
1591- Add "import thread" to the top of test modules that import the
1592 threading module (test_asynchat and test_threadedtempfile). This
1593 prevents test failures caused by a broken threading module resulting
1594 from a previously caught failed import.
1595
1596- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1597 needed on some platforms (e.g. Solaris 8) when the tests are run
1598 twice in succession.
1599
1600- Skip rather than fail test_sunaudiodev if no audio device is found.
1601
1602
1603What's New in Python 2.1c1?
1604===========================
1605
1606This list was significantly updated when 2.1c2 was released; the 2.1c1
1607release didn't mention most changes that were actually part of 2.1c1:
1608
1609Legal
1610
1611- Copyright was assigned to the Python Software Foundation (PSF) and a
1612 PSF license (very similar to the CNRI license) was added.
1613
1614- The CNRI copyright notice was updated to include 2001.
1615
1616Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001617
Guido van Rossumc9932722001-04-12 02:31:27 +00001618- After a public outcry, assignment to __debug__ is no longer illegal;
1619 instead, a warning is issued. It will become illegal in 2.2.
1620
Guido van Rossum5b08f132001-04-16 02:05:23 +00001621- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1622 "%#x" now always prepends "0x", even if the value is zero.
1623
1624- Fixed some nits in the bytecode compiler.
1625
1626- Fixed core dumps when calling certain kinds of non-functions.
1627
1628- Fixed various core dumps caused by reference count bugs.
1629
1630Build and Ports
1631
1632- Use INSTALL_SCRIPT to install script files.
1633
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001634- New port: SCO Unixware 7, by Billy G. Allie.
1635
Guido van Rossum5b08f132001-04-16 02:05:23 +00001636- Updated RISCOS port.
1637
1638- Updated BeOS port and notes.
1639
1640- Various other porting problems resolved.
1641
1642Library
1643
1644- The TERMIOS and SOCKET modules are now truly obsolete and
1645 unnecessary. Their symbols are incorporated in the termios and
1646 socket modules.
1647
1648- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1649 better tests for pickling.
1650
1651- threading: make Condition.wait() robust against KeyboardInterrupt.
1652
1653- zipfile: add support to zipfile to support opening an archive
1654 represented by an open file rather than a file name. Fix bug where
1655 the archive was not properly closed. Fixed a bug in this bugfix
1656 where flush() was called for a read-only file.
1657
1658- imputil: added an uninstall() method to the ImportManager.
1659
1660- Canvas: fixed bugs in lower() and tkraise() methods.
1661
1662- SocketServer: API change (added overridable close_request() method)
1663 so that the TCP server can explicitly close the request.
1664
1665- pstats: Eric Raymond added a simple interactive statistics browser,
1666 invoked when the module is run as a script.
1667
1668- locale: fixed a problem in format().
1669
1670- webbrowser: made it work when the BROWSER environment variable has a
1671 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1672 KDE 2. Fixed some other nits.
1673
1674- unittest: changes to allow using a different exception than
1675 AssertionError, and added a few more function aliases. Some other
1676 small changes.
1677
1678- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1679
1680- asynchat: fixed a critical bug in asynchat that slipped through the
1681 2.1b2 release. Fixed another rare bug.
1682
1683- Fix some unqualified except: clauses (always a bad code example).
1684
1685XML
1686
1687- pyexpat: new API get_version_string().
1688
1689- Fixed some minidom bugs.
1690
1691Extensions
1692
1693- Fixed a core dump in _weakref. Removed the weakref.mapping()
1694 function (it adds nothing to the API).
1695
1696- Rationalized the use of header files in the readline module, to make
1697 it compile (albeit with some warnings) with the very recent readline
1698 4.2, without breaking for earlier versions.
1699
1700- Hopefully fixed a buffering problem in linuxaudiodev.
1701
1702- Attempted a fix to make the OpenSSL support in the socket module
1703 work again with pre-0.9.5 versions of OpenSSL.
1704
1705Tests
1706
1707- Added a test case for asynchat and asyncore.
1708
1709- Removed coupling between tests where one test failing could break
1710 another.
1711
1712Tools
1713
1714- Ping added an interactive help browser to pydoc, fixed some nits
1715 in the rest of the pydoc code, and added some features to his
1716 inspect module.
1717
1718- An updated python-mode.el version 4.1 which integrates Ken
1719 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1720 much nicer in XEmacs and Emacs. When stepping through your program
1721 with pdb, in either the shell window or the *Python* window, the
1722 source file and line will be tracked by an arrow. Very cool!
1723
1724- IDLE: syntax warnings in interactive mode are changed into errors.
1725
1726- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001727 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001728
1729- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001730
Barry Warsaw11e89c72001-04-11 20:37:57 +00001731
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001732What's New in Python 2.1 beta 2?
1733================================
1734
Guido van Rossum053ae352001-03-22 14:17:21 +00001735(Unlisted are many fixed bugs, more documentation, etc.)
1736
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001737Core language, builtins, and interpreter
1738
Guido van Rossum053ae352001-03-22 14:17:21 +00001739- The nested scopes work (enabled by "from __future__ import
1740 nested_scopes") is completed; in particular, the future now extends
1741 into code executed through exec, eval() and execfile(), and into the
1742 interactive interpreter.
1743
1744- When calling a base class method (e.g. BaseClass.__init__(self)),
1745 this is now allowed even if self is not strictly spoken a class
1746 instance (e.g. when using metaclasses or the Don Beaudry hook).
1747
1748- Slice objects are now comparable but not hashable; this prevents
1749 dict[:] from being accepted but meaningless.
1750
1751- Complex division is now calculated using less braindead algorithms.
1752 This doesn't change semantics except it's more likely to give useful
1753 results in extreme cases. Complex repr() now uses full precision
1754 like float repr().
1755
1756- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1757
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001758- It is illegal to assign to the name __debug__, which is set when the
1759 interpreter starts. It is effectively a compile-time constant.
1760
1761- A warning will be issued if a global statement for a variable
1762 follows a use or assignment of that variable.
1763
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001764Standard library
1765
Guido van Rossum053ae352001-03-22 14:17:21 +00001766- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1767 inspired by JUnit), is now part of the standard library. You now
1768 have a choice of two testing frameworks: unittest requires you to
1769 write testcases as separate code, doctest gathers them from
1770 docstrings. Both approaches have their advantages and
1771 disadvantages.
1772
1773- A new module Tix was added, which wraps the Tix extension library
1774 for Tk. With that module, it is not necessary to statically link
1775 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1776 require" command. See Demo/tix/.
1777
1778- tzparse.py is now obsolete.
1779
1780- In gzip.py, the seek() and tell() methods are removed -- they were
1781 non-functional anyway, and it's better if callers can test for their
1782 existence with hasattr().
1783
1784Python/C API
1785
1786- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1787 that's already in the dictionary during a PyDict_Next() iteration.
1788 This used to fail occasionally when a dictionary resize operation
1789 could be triggered that would rehash all the keys. All other
1790 modifications to the dictionary are still off-limits during a
1791 PyDict_Next() iteration!
1792
1793- New extended APIs related to passing compiler variables around.
1794
1795- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1796 implement isinstance() and issubclass().
1797
1798- Py_BuildValue() now has a "D" conversion to create a Python complex
1799 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001800
Fred Drake4e262a92001-03-22 18:26:47 +00001801- Extensions types which support weak references must now set the
1802 field allocated for the weak reference machinery to NULL themselves;
1803 this is done to avoid the cost of checking each object for having a
1804 weakly referencable type in PyObject_INIT(), since most types are
1805 not weakly referencable.
1806
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001807- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1808 free variables and cell variables to and from the frame's f_locals.
1809
1810- Variants of several functions defined in pythonrun.h have been added
1811 to support the nested_scopes future statement. The variants all end
1812 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1813 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1814 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001815 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001816
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001817Distutils
1818
1819- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1820 into the release tree.
1821
Tim Peters0e57abf2001-05-02 07:39:38 +00001822- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001823 (an uninstaller, more customization of the installer's display)
1824
1825- from Jack Jansen: added Mac-specific code to generate a dialog for
1826 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001827 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001828 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001829
1830- added 'platforms' and 'keywords' to the set of metadata that can be
1831 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001832
1833- applied patches from Jason Tishler to make the compiler class work with
1834 Cygwin.
1835
1836
Tim Peters2fe289a2001-03-01 22:19:38 +00001837What's New in Python 2.1 beta 1?
1838================================
Tim Petersd66595f2001-02-04 03:09:53 +00001839
1840Core language, builtins, and interpreter
1841
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001842- Following an outcry from the community about the amount of code
1843 broken by the nested scopes feature introduced in 2.1a2, we decided
1844 to make this feature optional, and to wait until Python 2.2 (or at
1845 least 6 months) to make it standard. The option can be enabled on a
1846 per-module basis by adding "from __future__ import nested_scopes" at
1847 the beginning of a module (before any other statements, but after
1848 comments and an optional docstring). See PEP 236 (Back to the
1849 __future__) for a description of the __future__ statement. PEP 227
1850 (Statically Nested Scopes) has been updated to reflect this change,
1851 and to clarify the semantics in a number of endcases.
1852
1853- The nested scopes code, when enabled, has been hardened, and most
1854 bugs and memory leaks in it have been fixed.
1855
1856- Compile-time warnings are now generated for a number of conditions
1857 that will break or change in meaning when nested scopes are enabled:
1858
1859 - Using "from...import *" or "exec" without in-clause in a function
1860 scope that also defines a lambda or nested function with one or
1861 more free (non-local) variables. The presence of the import* or
1862 bare exec makes it impossible for the compiler to determine the
1863 exact set of local variables in the outer scope, which makes it
1864 impossible to determine the bindings for free variables in the
1865 inner scope. To avoid the warning about import *, change it into
1866 an import of explicitly name object, or move the import* statement
1867 to the global scope; to avoid the warning about bare exec, use
1868 exec...in... (a good idea anyway -- there's a possibility that
1869 bare exec will be deprecated in the future).
1870
1871 - Use of a global variable in a nested scope with the same name as a
1872 local variable in a surrounding scope. This will change in
1873 meaning with nested scopes: the name in the inner scope will
1874 reference the variable in the outer scope rather than the global
1875 of the same name. To avoid the warning, either rename the outer
1876 variable, or use a global statement in the inner function.
1877
Neil Schemenauera35c6882001-02-27 04:45:05 +00001878- An optional object allocator has been included. This allocator is
1879 optimized for Python objects and should be faster and use less memory
1880 than the standard system allocator. It is not enabled by default
1881 because of possible thread safety problems. The allocator is only
1882 protected by the Python interpreter lock and it is possible that some
1883 extension modules require a thread safe allocator. The object
1884 allocator can be enabled by providing the "--with-pymalloc" option to
1885 configure.
1886
Tim Petersd66595f2001-02-04 03:09:53 +00001887Standard library
1888
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001889- pyexpat now detects the expat version if expat.h defines it. A
1890 number of additional handlers are provided, which are only available
1891 since expat 1.95. In addition, the methods SetParamEntityParsing and
1892 GetInputContext of Parser objects are available with 1.95.x
1893 only. Parser objects now provide the ordered_attributes and
1894 specified_attributes attributes. A new module expat.model was added,
1895 which offers a number of additional constants if 1.95.x is used.
1896
1897- xml.dom offers the new functions registerDOMImplementation and
1898 getDOMImplementation.
1899
1900- xml.dom.minidom offers a toprettyxml method. A number of DOM
1901 conformance issues have been resolved. In particular, Element now
1902 has an hasAttributes method, and the handling of namespaces was
1903 improved.
1904
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001905- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1906 getting information about live Python code, and pydoc.py, a module
1907 for interactively converting docstrings to HTML or text.
1908 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001909 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001910 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1911 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001912
Tim Peters1eff7962001-03-01 02:31:33 +00001913- New library module difflib.py, primarily packaging the SequenceMatcher
1914 class at the heart of the popular ndiff.py file-comparison tool.
1915
1916- doctest.py (a framework for verifying Python code examples in docstrings)
1917 is now part of the std library.
1918
Tim Petersd66595f2001-02-04 03:09:53 +00001919Windows changes
1920
Guido van Rossume3955a82001-03-02 14:05:59 +00001921- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1922 small GUI that lets you browse the module docstrings using your
1923 default web browser.
1924
Tim Peters1eff7962001-03-01 02:31:33 +00001925- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1926 Platforms) is implemented. See
1927
1928 http://python.sourceforge.net/peps/pep-0235.html
1929
1930 for full details, especially the "Current Lower-Left Semantics" section.
1931 The new Windows import rules are simpler than before:
1932
1933 A. If the PYTHONCASEOK environment variable exists, same as
1934 before: silently accept the first case-insensitive match of any
1935 kind; raise ImportError if none found.
1936
1937 B. Else search sys.path for the first case-sensitive match; raise
1938 ImportError if none found.
1939
1940 The same rules have been implented on other platforms with case-
1941 insensitive but case-preserving filesystems too (including Cygwin, and
1942 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001943
Tim Peters25a9ce32001-02-19 07:06:36 +00001944- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1945 what it's supposed to do (and does do under NT and 2000) via direct
1946 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001947 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001948 all Win9x systems before.
1949
Tim Peters1eff7962001-03-01 02:31:33 +00001950- Build: Subproject _test (effectively) renamed to _testcapi.
1951
Tim Peters2fe289a2001-03-01 22:19:38 +00001952New platforms
1953
1954- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1955 Thanks to Steven Majewski!
1956
1957- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1958 Tishler!
1959
Guido van Rossum9089b272001-03-02 06:49:50 +00001960- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1961 Schwertberger! See RISCOS/README for more information -- it seems
1962 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001963 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001964
Tim Peters25a9ce32001-02-19 07:06:36 +00001965
Tim Petersd7b5e882001-01-25 03:36:26 +00001966What's New in Python 2.1 alpha 2?
1967=================================
Tim Peters40ead762001-01-27 05:35:26 +00001968
Tim Petersd7b5e882001-01-25 03:36:26 +00001969Core language, builtins, and interpreter
1970
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001971- Scopes nest. If a name is used in a function or class, but is not
1972 local, the definition in the nearest enclosing function scope will
1973 be used. One consequence of this change is that lambda statements
1974 could reference variables in the namespaces where the lambda is
1975 defined. In some unusual cases, this change will break code.
1976
1977 In all previous version of Python, names were resolved in exactly
1978 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001979 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001980 function A is defined within a function B, the names bound in B are
1981 not visible in A. The new rules make names bound in B visible in A,
1982 unless A contains a name binding that hides the binding in B.
1983
1984 Section 4.1 of the reference manual describes the new scoping rules
1985 in detail. The test script in Lib/test/test_scope.py demonstrates
1986 some of the effects of the change.
1987
1988 The new rules will cause existing code to break if it defines nested
1989 functions where an outer function has local variables with the same
1990 name as globals or builtins used by the inner function. Example:
1991
1992 def munge(str):
1993 def helper(x):
1994 return str(x)
1995 if type(str) != type(''):
1996 str = helper(str)
1997 return str.strip()
1998
1999 Under the old rules, the name str in helper() is bound to the
2000 builtin function str(). Under the new rules, it will be bound to
2001 the argument named str and an error will occur when helper() is
2002 called.
2003
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002004- The compiler will report a SyntaxError if "from ... import *" occurs
2005 in a function or class scope. The language reference has documented
2006 that this case is illegal, but the compiler never checked for it.
2007 The recent introduction of nested scope makes the meaning of this
2008 form of name binding ambiguous. In a future release, the compiler
2009 may allow this form when there is no possibility of ambiguity.
2010
Tim Peters40ead762001-01-27 05:35:26 +00002011- repr(string) is easier to read, now using hex escapes instead of octal,
2012 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2013
2014 >>> "\texample \r\n" + chr(0) + chr(255)
2015 '\texample \r\n\x00\xff' # in 2.1
2016 '\011example \015\012\000\377' # in 2.0
2017
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002018- Functions are now compared and hashed by identity, not by value, since
2019 the func_code attribute is writable.
2020
Fred Drakefb9d7122001-02-01 20:00:40 +00002021- Weak references (PEP 205) have been added. This involves a few
2022 changes in the core, an extension module (_weakref), and a Python
2023 module (weakref). The weakref module is the public interface. It
2024 includes support for "explicit" weak references, proxy objects, and
2025 mappings with weakly held values.
2026
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002027- A 'continue' statement can now appear in a try block within the body
2028 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002029 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002030
Tim Petersd7b5e882001-01-25 03:36:26 +00002031Standard library
2032
Barry Warsaw30dbd142001-01-31 22:14:01 +00002033- mailbox.py now has a new class, PortableUnixMailbox which is
2034 identical to UnixMailbox but uses a more portable scheme for
2035 determining From_ separators. Also, the constructors for all the
2036 classes in this module have a new optional `factory' argument, which
2037 is a callable used when new message classes must be instantiated by
2038 the next() method.
2039
Tim Petersd7b5e882001-01-25 03:36:26 +00002040- random.py is now self-contained, and offers all the functionality of
2041 the now-deprecated whrandom.py. See the docs for details. random.py
2042 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002043 and restoring the internal state of the generator; and jumpahead(n),
2044 for quickly forcing the internal state to be the same as if n calls to
2045 random() had been made. The latter is particularly useful for multi-
2046 threaded programs, creating one instance of the random.Random() class for
2047 each thread, then using .jumpahead() to force each instance to use a
2048 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002049
Tim Peters0de88fc2001-02-01 04:59:18 +00002050- random.py's seed() function is new. For bit-for-bit compatibility with
2051 prior releases, use the whseed function instead. The new seed function
2052 addresses two problems: (1) The old function couldn't produce more than
2053 about 2**24 distinct internal states; the new one about 2**45 (the best
2054 that can be done in the Wichmann-Hill generator). (2) The old function
2055 sometimes produced identical internal states when passed distinct
2056 integers, and there was no simple way to predict when that would happen;
2057 the new one guarantees to produce distinct internal states for all
2058 arguments in [0, 27814431486576L).
2059
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002060- The socket module now supports raw packets on Linux. The socket
2061 family is AF_PACKET.
2062
Tim Peters9ea17ac2001-02-02 05:57:15 +00002063- test_capi.py is a start at running tests of the Python C API. The tests
2064 are implemented by the new Modules/_testmodule.c.
2065
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002066- A new extension module, _symtable, provides provisional access to the
2067 internal symbol table used by the Python compiler. A higher-level
2068 interface will be added on top of _symtable in a future release.
2069
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002070- Removed the obsolete soundex module.
2071
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002072- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2073 the isSameNode method; NamedNodeMap the get method.
2074
2075- xml.sax.expatreader supports the lexical handler property; it
2076 generates comment, startCDATA, and endCDATA events.
2077
Tim Petersee826f82001-01-31 19:39:44 +00002078Windows changes
2079
2080- Build procedure: the zlib project is built in a different way that
2081 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002082 the zlib binary used. See PCbuild\readme.txt for details. Your old
2083 zlib-related directories can be deleted; you'll need to download fresh
2084 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002085
Tim Peters9ea17ac2001-02-02 05:57:15 +00002086- Build: New subproject _test for the benefit of test_capi.py (see above).
2087
Tim Petersb16c56f2001-02-02 21:24:51 +00002088- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2089 interface to some Python compiler internals).
2090
2091- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002092 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002093
Tim Petersa3a3a032000-11-30 05:22:44 +00002094What's New in Python 2.1 alpha 1?
2095=================================
2096
2097Core language, builtins, and interpreter
2098
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002099- There is a new Unicode companion to the PyObject_Str() API
2100 called PyObject_Unicode(). It behaves in the same way as the
2101 former, but assures that the returned value is an Unicode object
2102 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002103
Guido van Rossumf98eda02001-01-17 15:54:45 +00002104- The comparison operators support "rich comparison overloading" (PEP
2105 207). C extension types can provide a rich comparison function in
2106 the new tp_richcompare slot in the type object. The cmp() function
2107 and the C function PyObject_Compare() first try the new rich
2108 comparison operators before trying the old 3-way comparison. There
2109 is also a new C API PyObject_RichCompare() (which also falls back on
2110 the old 3-way comparison, but does not constrain the outcome of the
2111 rich comparison to a Boolean result).
2112
2113 The rich comparison function takes two objects (at least one of
2114 which is guaranteed to have the type that provided the function) and
2115 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2116 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2117 object, which may be NotImplemented (in which case the tp_compare
2118 slot function is used as a fallback, if defined).
2119
2120 Classes can overload individual comparison operators by defining one
2121 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002122 __ge__. There are no explicit "reflected argument" versions of
2123 these; instead, __lt__ and __gt__ are each other's reflection,
2124 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2125 reflection (similar at the C level). No other implications are
2126 made; in particular, Python does not assume that == is the Boolean
2127 inverse of !=, or that < is the Boolean inverse of >=. This makes
2128 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002129
2130 Classes or types that want to implement (in)equality tests but not
2131 the ordering operators (i.e. unordered types) should implement ==
2132 and !=, and raise an error for the ordering operators.
2133
Guido van Rossuma88479f2001-01-18 14:28:08 +00002134 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002135 Boolean; e.g. a matrix type might want to return a matrix of bits
2136 for A < B, giving elementwise comparisons. Such types should ensure
2137 that any interpretation of their value in a Boolean context raises
2138 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2139 at the C level) to always raise an exception.
2140
Guido van Rossuma88479f2001-01-18 14:28:08 +00002141- Complex numbers use rich comparisons to define == and != but raise
2142 an exception for <, <=, > and >=. Unfortunately, this also means
2143 that cmp() of two complex numbers raises an exception when the two
2144 numbers differ. Since it is not mathematically meaningful to compare
2145 complex numbers except for equality, I hope that this doesn't break
2146 too much code.
2147
Tim Peters3389f192001-02-18 08:48:49 +00002148- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002149 not defined by the language, other than that it's arbitrary but
2150 consistent (see the Reference Manual). An implementation detail changed
2151 in 2.1a1 such that None now compares less than any other object. Code
2152 relying on this new behavior (like code that relied on the previous
2153 behavior) does so at its own risk.
2154
Barry Warsaw573b5412001-01-15 20:43:18 +00002155- Functions and methods now support getting and setting arbitrarily
2156 named attributes (PEP 232). Functions have a new __dict__
2157 (a.k.a. func_dict) which hold the function attributes. Methods get
2158 and set attributes on their underlying im_func. It is a TypeError
2159 to set an attribute on a bound method.
2160
Guido van Rossum051e3352001-01-15 19:11:10 +00002161- The xrange() object implementation has been improved so that
2162 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2163 limitation that in this case len(xrange(sys.maxint)) can't be
2164 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2165 work fine as long as the index i doesn't actually reach 2**31.
2166 (Python uses regular ints for sequence and string indices; fixing
2167 that is much more work.)
2168
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002169- Two changes to from...import:
2170
Guido van Rossumba381232001-02-03 15:06:40 +00002171 1) "from M import X" now works even if (after loading module M)
2172 sys.modules['M'] is not a real module; it's basically a getattr()
2173 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002174
2175 2) "from M import *" now looks for M.__all__ to decide which names to
2176 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2177 filters out names starting with '_' as before. Whether or not
2178 __all__ exists, there's no restriction on the type of M.
2179
Guido van Rossumf61f1662001-01-10 20:13:55 +00002180- File objects have a new method, xreadlines(). This is the fastest
2181 way to iterate over all lines in a file:
2182
2183 for line in file.xreadlines():
2184 ...do something to line...
2185
2186 See the xreadlines module (mentioned below) for how to do this for
2187 other file-like objects.
2188
2189- Even if you don't use file.xreadlines(), you may expect a speedup on
2190 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002191 quite a bit in platform-specific ways: on systems (like Linux) that
2192 support flockfile(), getc_unlocked(), and funlockfile(), those are
2193 used by default. On systems (like Windows) without getc_unlocked(),
2194 a complicated (but still thread-safe) method using fgets() is used by
2195 default.
2196
Tim Petersd52269b2001-01-25 06:23:18 +00002197 You can force use of the fgets() method by #define'ing
2198 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002199 getc_unlocked()).
2200
Tim Petersd52269b2001-01-25 06:23:18 +00002201 You can force fgets() not to be used by #define'ing
2202 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002203 test_bufio.py fails -- and let us know if it does!).
2204
2205- In addition, the fileinput module, while still slower than the other
2206 methods on most platforms, has been sped up too, by using
2207 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002208
2209- Support for run-time warnings has been added, including a new
2210 command line option (-W) to specify the disposition of warnings.
2211 See the description of the warnings module below.
2212
2213- Extensive changes have been made to the coercion code. This mostly
2214 affects extension modules (which can now implement mixed-type
2215 numerical operators without having to use coercion), but
2216 occasionally, in boundary cases the coercion semantics have changed
2217 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002218 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002219 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002220 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002221
Guido van Rossumf98eda02001-01-17 15:54:45 +00002222- In connection with the coercion changes, a new built-in singleton
2223 object, NotImplemented is defined. This can be returned for
2224 operations that wish to indicate they are not implemented for a
2225 particular combination of arguments. From C, this is
2226 Py_NotImplemented.
2227
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002228- The interpreter accepts now bytecode files on the command line even
2229 if they do not have a .pyc or .pyo extension. On Linux, after executing
2230
Martin v. Löwise214baa2001-02-04 22:37:56 +00002231import imp,sys,string
2232magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2233reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2234open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002235
2236 any byte code file can be used as an executable (i.e. as an argument
2237 to execve(2)).
2238
Tim Peters9940b802000-12-01 07:59:35 +00002239- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002240 character. In 1.6 and earlier, they never produced a sign,
2241 and raised an error if the value of the long was too large
2242 to fit in a Python int. In 2.0, they produced a sign if and
2243 only if too large to fit in an int. This was inconsistent
2244 across platforms (because the size of an int varies across
2245 platforms), and inconsistent with hex() and oct(). Example:
2246
2247 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002248 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002249 'ffffffbe' # in 2.0 and before, on 32-bit machines
2250 >>> hex(-0x42L)
2251 '-0x42L' # in all versions of Python
2252
Tim Peters9940b802000-12-01 07:59:35 +00002253 The behavior of %d formats for negative Python longs remains
2254 the same as in 2.0 (although in 1.6 and before, they raised
2255 an error if the long didn't fit in a Python int).
2256
2257 %u formats don't make sense for Python longs, but are allowed
2258 and treated the same as %d in 2.1. In 2.0, a negative long
2259 formatted via %u produced a sign if and only if too large to
2260 fit in an int. In 1.6 and earlier, a negative long formatted
2261 via %u raised an error if it was too big to fit in an int.
2262
Guido van Rossum3661d392000-12-12 22:10:31 +00002263- Dictionary objects have an odd new method, popitem(). This removes
2264 an arbitrary item from the dictionary and returns it (in the form of
2265 a (key, value) pair). This can be useful for algorithms that use a
2266 dictionary as a bag of "to do" items and repeatedly need to pick one
2267 item. Such algorithms normally end up running in quadratic time;
2268 using popitem() they can usually be made to run in linear time.
2269
Tim Peters36cdad12000-12-29 02:06:45 +00002270Standard library
2271
Thomas Woutersfe385252001-01-19 23:16:56 +00002272- In the time module, the time argument to the functions strftime,
2273 localtime, gmtime, asctime and ctime is now optional, defaulting to
2274 the current time (in the local timezone).
2275
Guido van Rossumda91f222001-01-15 16:36:08 +00002276- The ftplib module now defaults to passive mode, which is deemed a
2277 more useful default given that clients are often inside firewalls
2278 these days. Note that this could break if ftplib is used to connect
2279 to a *server* that is inside a firewall, from outside; this is
2280 expected to be a very rare situation. To fix that, you can call
2281 ftp.set_pasv(0).
2282
Martin v. Löwis10a27872001-01-13 09:54:41 +00002283- The module site now treats .pth files not only for path configuration,
2284 but also supports extensions to the initialization code: Lines starting
2285 with import are executed.
2286
Guido van Rossumf61f1662001-01-10 20:13:55 +00002287- There's a new module, warnings, which implements a mechanism for
2288 issuing and filtering warnings. There are some new built-in
2289 exceptions that serve as warning categories, and a new command line
2290 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2291 turns warnings into errors). warnings.warn(message[, category])
2292 issues a warning message; this can also be called from C as
2293 PyErr_Warn(category, message).
2294
2295- A new module xreadlines was added. This exports a single factory
2296 function, xreadlines(). The intention is that this code is the
2297 absolutely fastest way to iterate over all lines in an open
2298 file(-like) object:
2299
2300 import xreadlines
2301 for line in xreadlines.xreadlines(file):
2302 ...do something to line...
2303
2304 This is equivalent to the previous the speed record holder using
2305 file.readlines(sizehint). Note that if file is a real file object
2306 (as opposed to a file-like object), this is equivalent:
2307
2308 for line in file.xreadlines():
2309 ...do something to line...
2310
Tim Peters36cdad12000-12-29 02:06:45 +00002311- The bisect module has new functions bisect_left, insort_left,
2312 bisect_right and insort_right. The old names bisect and insort
2313 are now aliases for bisect_right and insort_right. XXX_right
2314 and XXX_left methods differ in what happens when the new element
2315 compares equal to one or more elements already in the list: the
2316 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002317 right. Code that doesn't care where equal elements end up should
2318 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002319
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002320- The new curses.panel module wraps the panel library that forms part
2321 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2322
Guido van Rossumf61f1662001-01-10 20:13:55 +00002323- The SocketServer module now sets the allow_reuse_address flag by
2324 default in the TCPServer class.
2325
2326- A new function, sys._getframe(), returns the stack frame pointer of
2327 the caller. This is intended only as a building block for
2328 higher-level mechanisms such as string interpolation.
2329
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002330- The pyexpat module supports a number of new handlers, which are
2331 available only in expat 1.2. If invocation of a callback fails, it
2332 will report an additional frame in the traceback. Parser objects
2333 participate now in garbage collection. If expat reports an unknown
2334 encoding, pyexpat will try to use a Python codec; that works only
2335 for single-byte charsets. The parser type objects is exposed as
2336 XMLParserObject.
2337
2338- xml.dom now offers standard definitions for symbolic node type and
2339 exception code constants, and a hierarchy of DOM exceptions. minidom
2340 was adjusted to use them.
2341
2342- The conformance of xml.dom.minidom to the DOM specification was
2343 improved. It detects a number of additional error cases; the
2344 previous/next relationship works even when the tree is modified;
2345 Node supports the normalize() method; NamedNodeMap, DocumentType and
2346 DOMImplementation classes were added; Element supports the
2347 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2348 method.
2349
Guido van Rossumf61f1662001-01-10 20:13:55 +00002350Build issues
2351
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002352- For Unix (and Unix-compatible) builds, configuration and building of
2353 extension modules is now greatly automated. Rather than having to
2354 edit the Modules/Setup file to indicate which modules should be
2355 built and where their include files and libraries are, a
2356 distutils-based setup.py script now takes care of building most
2357 extension modules. All extension modules built this way are built
2358 as shared libraries. Only a few modules that must be linked
2359 statically are still listed in the Setup file; you won't need to
2360 edit their configuration.
2361
2362- Python should now build out of the box on Cygwin. If it doesn't,
2363 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002364
2365- Python now always uses its own (renamed) implementation of getopt()
2366 -- there's too much variation among C library getopt()
2367 implementations.
2368
2369- C++ compilers are better supported; the CXX macro is always set to a
2370 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002371
Tim Petersd92dfe02000-12-12 01:18:41 +00002372Windows changes
2373
2374- select module: By default under Windows, a select() call
2375 can specify no more than 64 sockets. Python now boosts
2376 this Microsoft default to 512. If you need even more than
2377 that, see the MS docs (you'll need to #define FD_SETSIZE
2378 and recompile Python from source).
2379
Guido van Rossumf61f1662001-01-10 20:13:55 +00002380- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2381 subdirectory is no more!
2382
Tim Petersa3a3a032000-11-30 05:22:44 +00002383
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002384What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002385=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002386
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002387Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002388changes are in the file HISTORY. If you are making the jump directly
2389from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2390HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002391
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002392Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2393the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2394http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002395
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002396--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002397
2398======================================================================
2399
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002400What's new in 2.0 (since release candidate 1)?
2401==============================================
2402
2403Standard library
2404
2405- The copy_reg module was modified to clarify its intended use: to
2406 register pickle support for extension types, not for classes.
2407 pickle() will raise a TypeError if it is passed a class.
2408
2409- Fixed a bug in gettext's "normalize and expand" code that prevented
2410 it from finding an existing .mo file.
2411
2412- Restored support for HTTP/0.9 servers in httplib.
2413
Tim Peters989b7b92000-10-16 20:24:53 +00002414- The math module was changed to stop raising OverflowError in case of
2415 underflow, and return 0 instead in underflow cases. Whether Python
2416 used to raise OverflowError in case of underflow was platform-
2417 dependent (it did when the platform math library set errno to ERANGE
2418 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002419
2420- Fixed a bug in StringIO that occurred when the file position was not
2421 at the end of the file and write() was called with enough data to
2422 extend past the end of the file.
2423
2424- Fixed a bug that caused Tkinter error messages to get lost on
2425 Windows. The bug was fixed by replacing direct use of
2426 interp->result with Tcl_GetStringResult(interp).
2427
2428- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2429 redirect response.
2430
2431- Several changes were made to distutils: Some debugging code was
2432 removed from util. Fixed the installer used when an external zip
2433 program (like WinZip) is not found; the source code for this
2434 installer is in Misc/distutils. check_lib() was modified to behave
2435 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2436 test for whether installed modules are on sys.path was changed to
2437 use both normcase() and normpath().
2438
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002439- Several minor bugs were fixed in the xml package (the minidom,
2440 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002441
2442- The regression test driver (regrtest.py) behavior when invoked with
2443 -l changed: It now reports a count of objects that are recognized as
2444 garbage but not freed by the garbage collector.
2445
Tim Peters989b7b92000-10-16 20:24:53 +00002446- The regression test for the math module was changed to test
2447 exceptional behavior when the test is run in verbose mode. Python
2448 cannot yet guarantee consistent exception behavior across platforms,
2449 so the exception part of test_math is run only in verbose mode, and
2450 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002451
2452Internals
2453
2454- PyOS_CheckStack() has been disabled on Win64, where it caused
2455 test_sre to fail.
2456
2457Build issues
2458
2459- Changed compiler flags, so that gcc is always invoked with -Wall and
2460 -Wstrict-prototypes. Users compiling Python with GCC should see
2461 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002462 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002463 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002464
Tim Petersa3a3a032000-11-30 05:22:44 +00002465- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002466
2467Tools and other miscellany
2468
2469- The compiler in Tools/compiler was updated to support the new
2470 language features introduced in 2.0: extended print statement, list
2471 comprehensions, and augmented assignments. The new compiler should
2472 also be backwards compatible with Python 1.5.2; the compiler will
2473 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002474 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002475
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002476What's new in 2.0 release candidate 1 (since beta 2)?
2477=====================================================
2478
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002479What is release candidate 1?
2480
2481We believe that release candidate 1 will fix all known bugs that we
2482intend to fix for the 2.0 final release. This release should be a bit
2483more stable than the previous betas. We would like to see even more
2484widespread testing before the final release, so we are producing this
2485release candidate. The final release will be exactly the same unless
2486any show-stopping (or brown bag) bugs are found by testers of the
2487release candidate.
2488
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002489All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002490to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002491
2492Core language, builtins, and interpreter
2493
2494- A bug that caused crashes when __coerce__ was used with augmented
2495 assignment, e.g. +=, was fixed.
2496
2497- Raise ZeroDivisionError when raising zero to a negative number,
2498 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2499 power operator and the result of math.pow(0.0, -2.0) will vary by
2500 platform. On Linux, it raises a ValueError.
2501
2502- A bug in Unicode string interpolation was fixed that occasionally
2503 caused errors with formats including "%%". For example, the
2504 following expression "%% %s" % u"abc" no longer raises a TypeError.
2505
2506- Compilation of deeply nested expressions raises MemoryError instead
2507 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2508
2509- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2510 rendering them useless. They are now written in binary mode again.
2511
2512Standard library
2513
2514- Keyword arguments are now accepted for most pattern and match object
2515 methods in SRE, the standard regular expression engine.
2516
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002517- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002518 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002519
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002520- Several bugs in the Unicode handling and error handling in _tkinter
2521 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002522
2523- Fix memory management errors in Merge() and Tkapp_Call() routines.
2524
2525- Several changes were made to cStringIO to make it compatible with
2526 the file-like object interface and with StringIO. If operations are
2527 performed on a closed object, an exception is raised. The truncate
2528 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002529 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002530
2531- There were many changes made to the linuxaudiodev module and its
2532 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002533 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002534
2535 Note that this module is named poorly, because it should work
2536 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002537 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002538
2539 The module now raises exceptions when errors occur instead of
2540 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2541 audio) and defines a getptr() method that calls the
2542 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2543
2544- The library_version attribute, introduced in an earlier beta, was
2545 removed because it can not be supported with early versions of the C
2546 readline library, which provides no way to determine the version at
2547 compile-time.
2548
2549- The binascii module is now enabled on Win64.
2550
Tim Peters46446d62000-10-09 21:19:31 +00002551- tokenize.py no longer suffers "recursion depth" errors when parsing
2552 programs with very long string literals.
2553
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002554Internals
2555
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002556- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002557 which is called when the interpreter starts up to determine where
2558 the standard library is installed. These vulnerabilities affect all
2559 previous versions of Python and can be exploited by setting very
2560 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2561 setuid Python script, although use of the wrapper in
2562 Misc/setuid-prog.c will eliminate the vulnerability.
2563
2564- Fixed garbage collection bugs in instance creation that were
2565 triggered when errors occurred during initialization. The solution,
2566 applied in cPickle and in PyInstance_New(), is to call
2567 PyObject_GC_Init() after the initialization of the object's
2568 container attributes is complete.
2569
2570- pyexpat adds definitions of PyModule_AddStringConstant and
2571 PyModule_AddObject if the Python version is less than 2.0, which
2572 provides compatibility with PyXML on Python 1.5.2.
2573
2574- If the platform has a bogus definition for LONG_BIT (the number of
2575 bits in a long), an error will be reported at compile time.
2576
2577- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2578 collection crashes and possibly other, unreported crashes.
2579
2580- Fixed a memory leak in _PyUnicode_Fini().
2581
2582Build issues
2583
2584- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002585 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002586 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002587
2588- The mmap.PAGESIZE constant is now initialized using sysconf when
2589 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2590
2591- The md5 file should now compile on all platforms.
2592
2593- The select module now compiles on platforms that do not define
2594 POLLRDNORM and related constants.
2595
2596- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002597 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002598
Jeremy Hylton10921202000-10-09 18:34:12 +00002599- BeOS: A number of changes were made to the build and installation
2600 process. ar-fake now operates on a directory of object files.
2601 dl_export.h is gone, and its macros now appear on the mwcc command
2602 line during build on PPC BeOS.
2603
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002604- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002605 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002606
2607- Cygwin: Support for shared libraries, Tkinter, and sockets.
2608
2609- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2610
2611Tools and other miscellany
2612
2613- Removed debugging prints from main used with freeze.
2614
Tim Peters46446d62000-10-09 21:19:31 +00002615- IDLE auto-indent no longer crashes when it encounters Unicode
2616 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002617
2618What's new in 2.0 beta 2 (since beta 1)?
2619========================================
2620
2621Core language, builtins, and interpreter
2622
Tim Peters482c0212000-09-26 06:33:09 +00002623- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002624 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002625
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002626- Add -h and -V command line options to print the usage message and
2627 Python version number and exit immediately.
2628
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002629- eval() and exec accept Unicode objects as code parameters.
2630
2631- getattr() and setattr() now also accept Unicode objects for the
2632 attribute name, which are converted to strings using the default
2633 encoding before lookup.
2634
2635- Multiplication on string and Unicode now does proper bounds
2636 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2637 string is too long."
2638
2639- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002640 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002641
Jeremy Hylton1b618592000-09-26 05:32:36 +00002642
2643Standard library and extensions
2644
Guido van Rossum5b08f132001-04-16 02:05:23 +00002645- socket module: the OpenSSL code now adds support for RAND_status()
2646 and EGD (Entropy Gathering Device).
2647
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002648- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002649 argument checking; it still takes no arguments.
2650
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002651- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002652
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002653- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002654
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002655- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002656
2657- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002658 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002659
2660- copy: Copy Unicode objects atomically.
2661
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002662- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002663
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002664- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002665
Fred Drake67233bc2000-09-26 16:40:27 +00002666- dbm: Add get() and setdefault() methods to dbm object. Add constant
2667 `library' to module that names the library used. Added doc strings
2668 and method names to error messages. Uses configure to determine
2669 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2670 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002671
2672- distutils: Update to version 0.9.3.
2673
2674- dl: Add several dl.RTLD_ constants.
2675
2676- fpectl: Now supported on FreeBSD.
2677
2678- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2679 found by the collector will be saved in gc.garbage. This is useful
2680 for debugging a program that creates reference cycles.
2681
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002682- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002683 of HTTP class. Do not close socket on zero-length response. Do not
2684 crash when server sends invalid content-length header.
2685
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002686- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002687
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002688- marshal: When reading a short, sign-extend on platforms where shorts
2689 are bigger than 16 bits. When reading a long, repair the unportable
2690 sign extension that was being done for 64-bit machines. (It assumed
2691 that signed right shift sign-extends.)
2692
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002693- operator: Add contains(), invert(), __invert__() as aliases for
2694 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002695
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002696- os: Add support for popen2() and popen3() on all platforms where
2697 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002698
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002699- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002700 clicking on a file in Explorer (or passing the file name to the
2701 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002702
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002703- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002704 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002705
2706- pickle: Now raises ValueError when an invalid pickle that contains
2707 a non-string repr where a string repr was expected. This behavior
2708 matches cPickle.
2709
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002710- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002711
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002712- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002713
2714- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002715 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002716 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002717
2718- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002719 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002720
2721- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002722 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002723 few cycles during startup since the first call to
2724 setdefaultencoding() will initialize the codec registry and the
2725 encodings package.
2726
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002727- socket: Support for size hint in readlines() method of object returned
2728 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002729
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002730- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002731 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002732 is followed by whitespace.
2733
Tim Petersa3a3a032000-11-30 05:22:44 +00002734- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002735
2736- struct: Check ranges for bytes and shorts.
2737
2738- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002739 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002740
2741- Tkinter: Image objects are now guaranteed to have unique ids. Set
2742 event.delta to zero if Tk version doesn't support mousewheel.
2743 Removed some debugging prints.
2744
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002745- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002746
Fred Drake67233bc2000-09-26 16:40:27 +00002747- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002748 which works around a bug in Norton AntiVirus 2000 that leads directly
2749 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002750
2751- xml: New version detection code allows PyXML to override standard
2752 XML package if PyXML version is greater than 0.6.1.
2753
Fred Drake64bb3802000-09-26 16:21:35 +00002754- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2755 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2756 tree only for nodes which are sufficiently interesting to a specific
2757 application. Does not provide the HTML-specific extensions. Still
2758 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002759
Fred Drake64bb3802000-09-26 16:21:35 +00002760- xml.sax: SAX 2 support for Python, including all the handler
2761 interfaces needed to process XML 1.0 compliant XML. Some
2762 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002763
Fred Drake64bb3802000-09-26 16:21:35 +00002764- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2765 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002766
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002767
Jeremy Hylton1b618592000-09-26 05:32:36 +00002768C API
2769
2770- Add three new convenience functions for module initialization --
2771 PyModule_AddObject(), PyModule_AddIntConstant(), and
2772 PyModule_AddStringConstant().
2773
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002774- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002775 removed and add #error to Python.h if NULL isn't defined after
2776 #include of stdio.h.
2777
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002778- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002779 backwards compatibility (at the source level) with old extensions.
2780
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002781- A wrapper API was added for signal() and sigaction(). Instead of
2782 either function, always use PyOS_getsig() to get a signal handler
2783 and PyOS_setsig() to set one. A new convenience typedef
2784 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002785
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002786- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002787 internal data buffer and size of a string object -- or the default
2788 encoded version of a Unicode object.
2789
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002790- PyString_Size() and PyString_AsString() accept Unicode objects.
2791
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002792- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002793 exists). INT_MAX and LONG_MAX will always be defined, even if
2794 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002795
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002796- PyFloat_FromString takes a second argument, pend, that was
2797 effectively useless. It is now officially useless but preserved for
2798 backwards compatibility. If the pend argument is not NULL, *pend is
2799 set to NULL.
2800
2801- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2802 for the attribute name. See note on getattr() above.
2803
2804- A few bug fixes to argument processing for Unicode.
2805 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2806 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2807 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002808 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002809
2810- Py_BuildValue accepts B format (for bgen-generated code).
2811
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002812
Jeremy Hylton1b618592000-09-26 05:32:36 +00002813Internals
2814
2815- On Unix, fix code for finding Python installation directory so that
2816 it works when argv[0] is a relative path.
2817
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002818- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002819 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002820 rather than by generating a copy of the object.
2821
Tim Peters482c0212000-09-26 06:33:09 +00002822- Several of the internal Unicode tables are much smaller now, and
2823 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002824
Jeremy Hylton97693b02000-09-26 17:42:51 +00002825- In the garbage collector: Fixed bug in collection of tuples. Fixed
2826 bug that caused some instances to be removed from the container set
2827 while they were still live. Fixed parsing in gc.set_debug() for
2828 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002829
2830- Fixed refcount problem in instance deallocation that only occurred
2831 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2832
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002833- On Windows, getpythonregpath is now protected against null data in
2834 registry key.
2835
2836- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002837 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002838
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002839
Jeremy Hylton1b618592000-09-26 05:32:36 +00002840Build and platform-specific issues
2841
2842- Better support of GNU Pth via --with-pth configure option.
2843
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002844- Python/C API now properly exposed to dynamically-loaded extension
2845 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002846
2847- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2848 Don't define MS_SYNC to be zero when it is undefined. Added missing
2849 prototypes in posixmodule.c.
2850
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002851- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002852 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002853
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002854- Fix largefile support on older NetBSD systems and OpenBSD by adding
2855 define for TELL64.
2856
2857
2858Tools and other miscellany
2859
2860- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2861
2862- freeze: The modulefinder now works with 2.0 opcodes.
2863
Tim Petersa3a3a032000-11-30 05:22:44 +00002864- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002865 Move hackery of sys.argv until after the Tk instance has been
2866 created, which allows the application-specific Tkinter
2867 initialization to be executed if present; also pass an explicit
2868 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002869
Jeremy Hylton1b618592000-09-26 05:32:36 +00002870
2871What's new in 2.0 beta 1?
2872=========================
2873
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002874Source Incompatibilities
2875------------------------
2876
2877None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2878such as single-argument append(), connect() and bind(), and changes to
2879str(long) and repr(float).
2880
2881
2882Binary Incompatibilities
2883------------------------
2884
2885- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2886with Python 2.0; these extensions will have to be rebuilt for Python
28872.0.
2888
2889- On Windows, attempting to import a third party extension built for
2890Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2891can do about this. Check your PYTHONPATH environment variable!
2892
2893- Python bytecode files (*.pyc and *.pyo) are not compatible between
2894releases.
2895
2896
2897Overview of Changes Since 1.6
2898-----------------------------
2899
2900There are many new modules (including brand new XML support through
2901the xml package, and i18n support through the gettext module); a list
2902of all new modules is included below. Lots of bugs have been fixed.
2903
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002904The process for making major new changes to the language has changed
2905since Python 1.6. Enhancements must now be documented by a Python
2906Enhancement Proposal (PEP) before they can be accepted.
2907
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002908There are several important syntax enhancements, described in more
2909detail below:
2910
2911 - Augmented assignment, e.g. x += 1
2912
2913 - List comprehensions, e.g. [x**2 for x in range(10)]
2914
2915 - Extended import statement, e.g. import Module as Name
2916
2917 - Extended print statement, e.g. print >> file, "Hello"
2918
2919Other important changes:
2920
2921 - Optional collection of cyclical garbage
2922
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002923Python Enhancement Proposal (PEP)
2924---------------------------------
2925
2926PEP stands for Python Enhancement Proposal. A PEP is a design
2927document providing information to the Python community, or describing
2928a new feature for Python. The PEP should provide a concise technical
2929specification of the feature and a rationale for the feature.
2930
2931We intend PEPs to be the primary mechanisms for proposing new
2932features, for collecting community input on an issue, and for
2933documenting the design decisions that have gone into Python. The PEP
2934author is responsible for building consensus within the community and
2935documenting dissenting opinions.
2936
2937The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002938
2939Augmented Assignment
2940--------------------
2941
2942This must have been the most-requested feature of the past years!
2943Eleven new assignment operators were added:
2944
Guido van Rossume905e952000-09-05 12:42:46 +00002945 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002946
2947For example,
2948
2949 A += B
2950
2951is similar to
2952
2953 A = A + B
2954
2955except that A is evaluated only once (relevant when A is something
2956like dict[index].attr).
2957
2958However, if A is a mutable object, A may be modified in place. Thus,
2959if A is a number or a string, A += B has the same effect as A = A+B
2960(except A is only evaluated once); but if a is a list, A += B has the
2961same effect as A.extend(B)!
2962
2963Classes and built-in object types can override the new operators in
2964order to implement the in-place behavior; the not-in-place behavior is
2965used automatically as a fallback when an object doesn't implement the
2966in-place behavior. For classes, the method name is derived from the
2967method name for the corresponding not-in-place operator by inserting
2968an 'i' in front of the name, e.g. __iadd__ implements in-place
2969__add__.
2970
2971Augmented assignment was implemented by Thomas Wouters.
2972
2973
2974List Comprehensions
2975-------------------
2976
2977This is a flexible new notation for lists whose elements are computed
2978from another list (or lists). The simplest form is:
2979
2980 [<expression> for <variable> in <sequence>]
2981
Guido van Rossum56db0952000-09-06 23:34:25 +00002982For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002983This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002984
2985You can also add a condition:
2986
2987 [<expression> for <variable> in <sequence> if <condition>]
2988
2989For example, [w for w in words if w == w.lower()] would yield the list
2990of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002991than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002992
2993You can also have nested for loops and more than one 'if' clause. For
2994example, here's a function that flattens a sequence of sequences::
2995
2996 def flatten(seq):
2997 return [x for subseq in seq for x in subseq]
2998
2999 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3000
3001This prints
3002
3003 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3004
3005List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003006Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003007
3008
3009Extended Import Statement
3010-------------------------
3011
3012Many people have asked for a way to import a module under a different
3013name. This can be accomplished like this:
3014
3015 import foo
3016 bar = foo
3017 del foo
3018
3019but this common idiom gets old quickly. A simple extension of the
3020import statement now allows this to be written as follows:
3021
3022 import foo as bar
3023
3024There's also a variant for 'from ... import':
3025
3026 from foo import bar as spam
3027
3028This also works with packages; e.g. you can write this:
3029
3030 import test.regrtest as regrtest
3031
3032Note that 'as' is not a new keyword -- it is recognized only in this
3033context (this is only possible because the syntax for the import
3034statement doesn't involve expressions).
3035
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003036Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003037
3038
3039Extended Print Statement
3040------------------------
3041
3042Easily the most controversial new feature, this extension to the print
3043statement adds an option to make the output go to a different file
3044than the default sys.stdout.
3045
3046For example, to write an error message to sys.stderr, you can now
3047write:
3048
3049 print >> sys.stderr, "Error: bad dog!"
3050
3051As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003052evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003053
3054 print >> None, "Hello world"
3055
3056is equivalent to
3057
3058 print "Hello world"
3059
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003060Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003061
3062
3063Optional Collection of Cyclical Garbage
3064---------------------------------------
3065
3066Python is now equipped with a garbage collector that can hunt down
3067cyclical references between Python objects. It's no replacement for
3068reference counting; in fact, it depends on the reference counts being
3069correct, and decides that a set of objects belong to a cycle if all
3070their reference counts can be accounted for from their references to
3071each other. This devious scheme was first proposed by Eric Tiedemann,
3072and brought to implementation by Neil Schemenauer.
3073
3074There's a module "gc" that lets you control some parameters of the
3075garbage collection. There's also an option to the configure script
3076that lets you enable or disable the garbage collection. In 2.0b1,
3077it's on by default, so that we (hopefully) can collect decent user
3078experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003079performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003080off by default in the final 2.0 release.
3081
3082
3083Smaller Changes
3084---------------
3085
3086A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3087map(None, seq1, seq2, ...) when the sequences have the same length;
3088i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3089the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003090zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003091
3092sys.version_info is a tuple (major, minor, micro, level, serial).
3093
3094Dictionaries have an odd new method, setdefault(key, default).
3095dict.setdefault(key, default) returns dict[key] if it exists; if not,
3096it sets dict[key] to default and returns that value. Thus:
3097
3098 dict.setdefault(key, []).append(item)
3099
3100does the same work as this common idiom:
3101
3102 if not dict.has_key(key):
3103 dict[key] = []
3104 dict[key].append(item)
3105
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003106There are two new variants of SyntaxError that are raised for
3107indentation-related errors: IndentationError and TabError.
3108
3109Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3110escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003111
3112The limits on the size of expressions and file in Python source code
3113have been raised from 2**16 to 2**32. Previous versions of Python
3114were limited because the maximum argument size the Python VM accepted
3115was 2**16. This limited the size of object constructor expressions,
3116e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3117limit was raised thanks to a patch by Charles Waldman that effectively
3118fixes the problem. It is now much more likely that you will be
3119limited by available memory than by an arbitrary limit in Python.
3120
3121The interpreter's maximum recursion depth can be modified by Python
3122programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3123limit is the maximum number of recursive calls that can be made by
3124Python code. The limit exists to prevent infinite recursion from
3125overflowing the C stack and causing a core dump. The default value is
31261000. The maximum safe value for a particular platform can be found
3127by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003128
3129New Modules and Packages
3130------------------------
3131
3132atexit - for registering functions to be called when Python exits.
3133
3134imputil - Greg Stein's alternative API for writing custom import
3135hooks.
3136
3137pyexpat - an interface to the Expat XML parser, contributed by Paul
3138Prescod.
3139
3140xml - a new package with XML support code organized (so far) in three
3141subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3142would fill a volume. There's a special feature whereby a
3143user-installed package named _xmlplus overrides the standard
3144xmlpackage; this is intended to give the XML SIG a hook to distribute
3145backwards-compatible updates to the standard xml package.
3146
3147webbrowser - a platform-independent API to launch a web browser.
3148
3149
Guido van Rossume905e952000-09-05 12:42:46 +00003150Changed Modules
3151---------------
3152
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003153array -- new methods for array objects: count, extend, index, pop, and
3154remove
3155
3156binascii -- new functions b2a_hex and a2b_hex that convert between
3157binary data and its hex representation
3158
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003159calendar -- Many new functions that support features including control
3160over which day of the week is the first day, returning strings instead
3161of printing them. Also new symbolic constants for days of week,
3162e.g. MONDAY, ..., SUNDAY.
3163
3164cgi -- FieldStorage objects have a getvalue method that works like a
3165dictionary's get method and returns the value attribute of the object.
3166
3167ConfigParser -- The parser object has new methods has_option,
3168remove_section, remove_option, set, and write. They allow the module
3169to be used for writing config files as well as reading them.
3170
3171ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003172optionally support the RFC 959 REST command.
3173
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003174gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003175
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003176httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3177the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003178
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003179locale -- implement getdefaultlocale for Win32 and Macintosh
3180
3181marshal -- no longer dumps core when marshaling deeply nested or
3182recursive data structures
3183
3184os -- new functions isatty, seteuid, setegid, setreuid, setregid
3185
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003186os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3187support under Unix.
3188
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003189os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003190
3191os.path -- fix semantics of os.path.commonprefix
3192
3193smtplib -- support for sending very long messages
3194
3195socket -- new function getfqdn()
3196
3197readline -- new functions to read, write and truncate history files.
3198The readline section of the library reference manual contains an
3199example.
3200
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003201select -- add interface to poll system call
3202
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003203shutil -- new copyfileobj function
3204
3205SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3206HTTP server.
3207
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003208Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003209
3210urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003211e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003212
3213whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003214
3215
3216Obsolete Modules
3217----------------
3218
3219None. However note that 1.6 made a whole slew of modules obsolete:
3220stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3221poly, zmod, strop, util, whatsound.
3222
3223
3224Changed, New, Obsolete Tools
3225----------------------------
3226
Tim Peters8b092332000-09-05 20:15:25 +00003227None.
Guido van Rossume905e952000-09-05 12:42:46 +00003228
3229
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003230C-level Changes
3231---------------
3232
3233Several cleanup jobs were carried out throughout the source code.
3234
3235All C code was converted to ANSI C; we got rid of all uses of the
3236Py_PROTO() macro, which makes the header files a lot more readable.
3237
3238Most of the portability hacks were moved to a new header file,
3239pyport.h; several other new header files were added and some old
3240header files were removed, in an attempt to create a more rational set
3241of header files. (Few of these ever need to be included explicitly;
3242they are all included by Python.h.)
3243
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003244Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003245and Win64, especially for the new Intel Itanium processor. Mick also
3246added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003247
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003248The C APIs to return an object's size have been update to consistently
3249use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3250previous versions, the abstract interfaces used PyXXX_Length and the
3251concrete interfaces used PyXXX_Size. The old names,
3252e.g. PyObject_Length, are still available for backwards compatibility
3253at the API level, but are deprecated.
3254
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003255The PyOS_CheckStack function has been implemented on Windows by
3256Fredrik Lundh. It prevents Python from failing with a stack overflow
3257on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003258
3259The GC changes resulted in creation of two new slots on object,
3260tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003261the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003262
3263The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003264C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003265
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003266PyErr_Format has been updated to automatically calculate the size of
3267the buffer needed to hold the formatted result string. This change
3268prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003269
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003270New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003271
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003272PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3273that are the same as their non-Ex counterparts except they take an
3274extra flag argument that tells them to close the file when done.
3275
3276XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003277
Tim Peters8b092332000-09-05 20:15:25 +00003278
3279Windows Changes
3280---------------
3281
3282New popen2/popen3/peopen4 in os module (see Changed Modules above).
3283
3284os.popen is much more usable on Windows 95 and 98. See Microsoft
3285Knowledge Base article Q150956. The Win9x workaround described there
3286is implemented by the new w9xpopen.exe helper in the root of your
3287Python installation. Note that Python uses this internally; it is not
3288a standalone program.
3289
3290Administrator privileges are no longer required to install Python
3291on Windows NT or Windows 2000. If you have administrator privileges,
3292Python's registry info will be written under HKEY_LOCAL_MACHINE.
3293Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003294under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003295uses of Python, but will prevent some advanced uses from working
3296(for example, running a Python script as an NT service, or possibly
3297from CGI).
3298
3299[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3300installer; instead, it installs the needed Tcl/Tk files directly in the
3301Python directory. If you already have a Tcl/Tk installation, this
3302wastes some disk space (about 4 Megs) but avoids problems with
3303conflicting Tcl/Tk installations, and makes it much easier for Python
3304to ensure that Tcl/Tk can find all its files.
3305
3306[This was new in 1.6] The Windows installer now installs by default in
3307\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3308
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003309
3310Updates to the changes between 1.5.2 and 1.6
3311--------------------------------------------
3312
3313The 1.6 NEWS file can't be changed after the release is done, so here
3314is some late-breaking news:
3315
3316New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3317and changes to getlocale() and setlocale().
3318
3319The new module is now enabled per default.
3320
3321It is not true that the encodings codecs cannot be used for normal
3322strings: the string.encode() (which is also present on 8-bit strings
3323!) allows using them for 8-bit strings too, e.g. to convert files from
3324cp1252 (Windows) to latin-1 or vice-versa.
3325
3326Japanese codecs are available from Tamito KAJIYAMA:
3327http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3328
3329
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003330======================================================================