blob: 9fb542d9003c8a3f807fcf132ea6d1e19f8a25b3 [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Raymond Hettinger5a04aec2002-06-25 00:25:30 +00009- Slices and repetitions of buffer objects now consistently return
10 a string. Formerly, strings would be returned most of the time,
11 but a buffer object would be returned when the repetition count
12 was one or when the slice range was all inclusive.
13
Guido van Rossumc7c36502002-06-21 01:29:25 +000014- The __slots__ variable can now mention "private" names, and the
15 right thing will happen (e.g. __slots__ = ["__foo"]).
16
Walter Dörwald3430d702002-06-17 10:43:59 +000017- Unicode objects in sys.path are no longer ignored but treated
18 as directory names.
19
Guido van Rossum9562bcf2002-06-14 21:31:18 +000020- The built-ins slice() and buffer() are now callable types. The
21 types classobj (formerly class), code, function, instance, and
22 instancemethod (formerly instance-method), which have no built-in
23 names but are accessible through the types module, are now also
24 callable. The type dict-proxy is renamed to dictproxy.
25
Neal Norwitz1f68fc72002-06-14 00:50:42 +000026- Fixed string.startswith and string.endswith builtin methods
27 so they accept negative indices. [SF bug 493951]
28
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000029- Fixed a bug with a continue inside a try block and a yield in the
30 finally clause. [SF bug 567538]
31
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000032- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000033 with a third "stride" parameter. For example, "hello world"[::-1]
34 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000035
Guido van Rossum9f7549b2002-06-10 21:39:42 +000036- Cycles going through the __class__ link of a new-style instance are
37 now detected by the garbage collector.
38
Guido van Rossum9923ffe2002-06-04 19:52:53 +000039- Classes using __slots__ are now properly garbage collected.
40 [SF bug 519621]
41
42- Tightened the __slots__ rules: a slot name must be a valid Python
43 identifier.
44
Guido van Rossum2e4e0262002-06-04 05:58:34 +000045- The constructor for the module type now requires a name argument and
46 takes an optional docstring argument. Previously, this constructor
47 ignored its arguments. As a consequence, deriving a class from a
48 module (not from the module type) is now illegal; previously this
49 created an unnamed module, just like invoking the module type did.
50 [SF bug 563060]
51
Neal Norwitzd68f5172002-05-29 15:54:55 +000052- A new warning PendingDeprecationWarning was added to provide
53 direction on features which are in the process of being deprecated.
54 The warning will not be printed by default. To see the pending
55 deprecations, use -Walways::PendingDeprecationWarning::
56 as a command line option or warnings.filterwarnings() in code.
57
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000058- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000059 for 'str' and 'unicode', and can be used instead of
60 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000061 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000062 is an abstract base class and cannot be instantiated directly.
63
Fred Draked0ba6362002-05-02 21:28:26 +000064- Deprecated features of xrange objects have been removed as
65 promised. The start, stop, and step attributes and the tolist()
66 method no longer exist. xrange repetition and slicing have been
67 removed.
68
Guido van Rossum7dab2422002-04-26 19:40:56 +000069- New builtin function enumerate(x), from PEP 279. Example:
70 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
71 The argument can be an arbitrary iterable object.
72
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000073- The assert statement no longer tests __debug__ at runtime. This means
74 that assert statements cannot be disabled by assigning a false value
75 to __debug__.
76
Walter Dörwald068325e2002-04-15 13:36:47 +000077- A method zfill() was added to str and unicode, that fills a numeric
78 string to the left with zeros. For example,
79 "+123".zfill(6) -> "+00123".
80
Guido van Rossum862fe3c2002-04-15 12:36:47 +000081- Complex numbers supported divmod() and the // and % operators, but
82 these make no sense. Since this was documented, they're being
83 deprecated now.
84
Guido van Rossum26dd8302002-04-26 20:11:29 +000085- String and unicode methods lstrip(), rstrip() and strip() now take
86 an optional argument that specifies the characters to strip. For
87 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000088
Guido van Rossumc69343b2002-04-12 19:22:48 +000089- Added a new dict method pop(key). This removes and returns the
90 value corresponding to key. [SF patch #539949]
91
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000092- Changed new-style class instantiation so that when C's __new__
93 method returns something that's not a C instance, its __init__ is
94 not called. [SF bug #537450]
95
Guido van Rossum181e41a2002-04-06 00:23:25 +000096- Fixed super() to work correctly with class methods. [SF bug #535444]
97
Guido van Rossum47834462002-04-04 15:21:33 +000098- A new built-in type, bool, has been added, as well as built-in
99 names for its two values, True and False. Comparisons and sundry
100 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000101 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000102 is backward compatible.
103
Guido van Rossum95b62a62002-03-29 01:07:24 +0000104- Fixed two bugs reported as SF #535905: under certain conditions,
105 deallocating a deeply nested structure could cause a segfault in the
106 garbage collector, due to interaction with the "trashcan" code;
107 access to the current frame during destruction of a local variable
108 could access a pointer to freed memory.
109
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000110- The optional object allocator ("pymalloc") has been enabled by
111 default. The recommended practice for memory allocation and
112 deallocation has been streamlined. A header file is included,
113 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
114 and lets them use the same API with Python versions from 1.5.2
115 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000116
Guido van Rossum8c842552002-03-14 23:05:54 +0000117- If you try to pickle an instance of a class that has __slots__ but
118 doesn't define or override __getstate__, a TypeError is now raised.
119 This is done by adding a bozo __getstate__ to the class that always
120 raises TypeError. (Before, this would appear to be pickled, but the
121 state of the slots would be lost.)
122
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000123- PyErr_Display will provide file and line information for all exceptions
124 that have an attribute print_file_and_line, not just SyntaxErrors.
125
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000126- The UTF-8 codec will now encode and decode Unicode surrogates
127 correctly and without raising exceptions for unpaired ones.
128
Neal Norwitz649b7592002-01-01 19:07:13 +0000129- file.xreadlines() now raises a ValueError if the file is closed:
130 Previously, an xreadlines object was returned which would raise
131 a ValueError when the xreadlines.next() method was called.
132
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000133- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000134 An exception will now be raised if more than one argument is used.
135
Tim Petersaf8446f2001-12-21 21:36:50 +0000136Extension modules
137
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000138- The 'new' module is no longer an extension, but a Python module that
139 only exists for backwards compatibility. Its contents are no longer
140 functions but callable type objects.
141
Tim Peters81b92512002-04-29 01:37:32 +0000142- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000143 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000144 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000145
Martin v. Löwis606edc12002-06-13 21:09:11 +0000146- posix.killpg, posix.mknod, and posix.getpgid have been added where
147 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000148
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000149- The locale module now exposes the C library's gettext interface.
150
Tim Petersfbf74f22002-03-14 19:06:01 +0000151- A security hole ("double free") was found in zlib-1.1.3, a popular
152 third party compression library used by some Python modules. The
153 hole was quickly plugged in zlib-1.1.4, and the Windows build of
154 Python now ships with zlib-1.1.4.
155
Martin v. Löwis688357e2002-04-08 21:28:20 +0000156- pwd, grp, and resource return enhanced tuples now, with symbolic
157 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000158
Martin v. Löwis99866332002-03-01 10:27:01 +0000159- array.array is now a type object. A new format character
160 'u' indicates Py_UNICODE arrays. For those, .tounicode and
161 .fromunicode methods are available. Arrays now support __iadd__
162 and __imul__.
163
Neal Norwitze790eae2002-01-01 21:14:12 +0000164- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000165 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
166 is called.
167
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000168- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
169 been added where available.
170
Tim Petersaf8446f2001-12-21 21:36:50 +0000171Library
172
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000173- Some fixes in the copy module: when an object is copied through its
174 __reduce__ method, there was no check for a __setstate__ method on
175 the result [SF patch 565085]; deepcopy should treat instances of
176 custom metaclasses the same way it treats instances of type 'type'
177 [SF patch 560794].
178
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000179- Sockets now support timeout mode. After s.settimeout(T), where T is
180 a float expressing seconds, subsequent operations raise an exception
181 if they cannot be completed within T seconds. To disable timeout
182 mode, use s.settimeout(None).
183
184- getopt.gnu_getopt was added. This supports GNU-style option
185 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000186
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000187- Stop using strings for exceptions. String objects used for
188 exceptions are now classes deriving from Exception. The objects
189 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
190 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000191
Walter Dörwald474458d2002-06-04 15:16:29 +0000192- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
193 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
194 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
195 big endian systems were added to the codecs module. The old names
196 BOM32_* and BOM64_* were off by a factor of 2.
197
Guido van Rossumf9257822002-06-18 20:43:18 +0000198- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000199
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000200- ftplib.retrlines() now tests for callback is None rather than testing
201 for False. Was causing an error when given a callback object which
202 was callable but also returned len() as zero. The change may
203 create new breakage if the caller relied on the undocumented behavior
204 and called with callback set to [] or some other False value not
205 identical to None.
206
Tim Peters46c04e12002-05-05 20:40:00 +0000207- random.gauss() uses a piece of hidden state used by nothing else,
208 and the .seed() and .whseed() methods failed to reset it. In other
209 words, setting the seed didn't completely determine the sequence of
210 results produced by random.gauss(). It does now. Programs repeatedly
211 mixing calls to a seed method with calls to gauss() may see different
212 results now.
213
Fred Drake7f781c92002-05-01 20:33:53 +0000214- The pickle.Pickler class grew a clear_memo() method to mimic that
215 provided by cPickle.Pickler.
216
Tim Peters81b92512002-04-29 01:37:32 +0000217- difflib's SequenceMatcher class now does a dynamic analysis of
218 which elements are so frequent as to constitute noise. For
219 comparing files as sequences of lines, this generally works better
220 than the IS_LINE_JUNK function, and function ndiff's linejunk
221 argument defaults to None now as a result. A happy benefit is
222 that SequenceMatcher may run much faster now when applied
223 to large files with many duplicate lines (for example, C program
224 text with lots of repeated "}" and "return NULL;" lines).
225
Guido van Rossum256705b2002-04-23 13:29:43 +0000226- New Text.dump() method in Tkinter module.
227
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000228- New distutils commands for building packagers were added to
229 support pkgtool on Solaris and swinstall on HP-UX.
230
231- distutils now has a new abstract binary packager base class
232 command/bdist_packager, which simplifies writing packagers.
233 This will hopefully provide the missing bits to encourage
234 people to submit more packagers, e.g. for Debian, FreeBSD
235 and other systems.
236
Guido van Rossumf9257822002-06-18 20:43:18 +0000237- The UTF-16, -LE and -BE stream readers now raise a
238 NotImplementedError for all calls to .readline(). Previously, they
239 used to just produce garbage or fail with an encoding error --
240 UTF-16 is a 2-byte encoding and the C lib's line reading APIs don't
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000241 work well with these.
242
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000243- compileall now supports quiet operation.
244
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000245- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000246 connections.
247
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000248- socket module: the SSL support was broken out of the main
249 _socket module C helper and placed into a new _ssl helper
250 which now gets imported by socket.py if available and working.
251
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000252- encodings package: added aliases for all supported IANA character
253 sets
254
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000255- ftplib: to safeguard the user's privacy, anonymous login will use
256 "anonymous@" as default password, rather than the real user and host
257 name.
258
Fred Drake36736122002-01-10 13:50:31 +0000259- webbrowser: tightened up the command passed to os.system() so that
260 arbitrary shell code can't be executed because a bogus URL was
261 passed in.
262
Tim Peters11bd9942002-02-01 00:52:29 +0000263- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000264 gettext.find an optional all argument. Translations will now fallback
265 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000266
Martin v. Löwis9668b932002-01-12 11:27:42 +0000267- distutils bdist commands now offer a --skip-build option.
268
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000269- warnings.warn now accepts a Warning instance as first argument.
270
Fred Drakefed7e852002-04-04 19:36:15 +0000271- The xml.sax.expatreader.ExpatParser class will no longer create
272 circular references by using itself as the locator that gets passed
273 to the content handler implementation. [SF bug #535474]
274
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000275- The email.Parser.Parser class now properly parses strings regardless
276 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
277 or CRLF). Also, the Header class's constructor default arguments
278 has changed slightly so that an explicit maxlinelen value is always
279 honored.
280
Tim Petersaf8446f2001-12-21 21:36:50 +0000281Tools/Demos
282
Marc-André Lemburg46260092002-04-04 16:17:11 +0000283- freeze.py now produces binaries which can import shared modules,
284 unlike before when this failed due to missing symbol exports in
285 the generated binary.
286
Tim Petersaf8446f2001-12-21 21:36:50 +0000287Build
288
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000289- The configure option --without-doc-strings can be used to remove the
290 doc strings from the builtin functions and modules; this reduces the
291 size of the executable.
292
Tim Peters639295f2002-04-21 07:30:30 +0000293- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
294 say how or when to configure it, or how to turn it off.
295
Martin v. Löwis1142de32002-03-29 16:28:31 +0000296- On Unix, a shared libpython2.3.so can be created with --enable-shared.
297
Tim Peters8deda702002-03-30 10:06:07 +0000298- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
299 preprocessor symbols were eliminated. The internal decisions they
300 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000301
Fred Drake7d28b732002-05-02 21:17:00 +0000302- The tools used to build the documentation now work under Cygwin as
303 well as Unix.
304
Skip Montanaro57454e52002-06-14 20:30:31 +0000305- The bsddb and dbm module builds have been changed to try and avoid version
306 skew problems and disable linkage with Berkeley DB 1.85 unless the
307 installer knows what s/he's doing. See the section on building these
308 modules in the README file for details.
309
Tim Petersaf8446f2001-12-21 21:36:50 +0000310C API
311
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000312- Added new macro PySequence_ITEM(o, i) that directly calls
313 sq_item without rechecking that o is a sequence and without
314 adjusting for negative indices.
315
Fred Draked0ba6362002-05-02 21:28:26 +0000316- PyRange_New() now raises ValueError if the fourth argument is not 1.
317 This is part of the removal of deprecated features of the xrange
318 object.
319
Guido van Rossum517c7d42002-04-26 02:49:14 +0000320- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
321 coercion if both arguments have the same type but this type has the
322 CHECKTYPES flag set. This is to better support proxies.
323
Neil Schemenauer9344b142002-04-12 23:00:08 +0000324- The type of tp_free has been changed from "void (*)(PyObject *)" to
325 "void (*)(void *)".
326
327- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
328
Guido van Rossum0986d822002-04-08 01:38:42 +0000329- A type can now inherit its metatype from its base type. Previously,
330 when PyType_Ready() was called, if ob_type was found to be NULL, it
331 was always set to &PyType_Type; now it is set to base->ob_type,
332 where base is tp_base, defaulting to &PyObject_Type.
333
334- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
335
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000336- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000337
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000338- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000339 without going through the buffer API.
340
Martin v. Löwis7198a522002-01-01 19:59:11 +0000341- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
342
Tim Peters10a3bb52001-12-25 19:07:38 +0000343- An old #define of ANY as void has been removed from pyport.h. This
344 hasn't been used since Python's pre-ANSI days, and the #define has
345 been marked as obsolete since then. SF bug 495548 says it created
346 conflicts with other packages, so keeping it around wasn't harmless.
347
Tim Petersaf8446f2001-12-21 21:36:50 +0000348- Because Python's magic number scheme broke on January 1st, we decided
349 to stop Python development. Thanks for all the fish!
350
Tim Petersfb05db22002-03-11 00:24:00 +0000351- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000352 scheme to a new one. See Python/import.c for details.
353
Tim Petersaf8446f2001-12-21 21:36:50 +0000354New platforms
355
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000356- AtheOS is now supported.
357
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000358- GNU/Hurd is now supported.
359
Tim Petersaf8446f2001-12-21 21:36:50 +0000360Tests
361
362Windows
363
Tim Peters08e72952002-04-16 20:48:01 +0000364- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
365 of that has been fixed in the installer (disabled Wise's "delete in-
366 use files" uninstall option).
367
Guido van Rossum181e41a2002-04-06 00:23:25 +0000368- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
369
Tim Peters33187922002-04-04 20:02:04 +0000370- The installer now installs Start menu shortcuts under (the local
371 equivalent of) "All Users" when doing an Admin install.
372
Tim Petersfb05db22002-03-11 00:24:00 +0000373- file.truncate([newsize]) now works on Windows for all newsize values.
374 It used to fail if newsize didn't fit in 32 bits, reflecting a
375 limitation of MS _chsize (which is no longer used).
376
Tim Petersab034fa2002-02-01 11:27:43 +0000377- os.waitpid() is now implemented for Windows, and can be used to block
378 until a specified process exits. This is similar to, but not exactly
379 the same as, os.waitpid() on POSIX systems. If you're waiting for
380 a specific process whose pid was obtained from one of the spawn()
381 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000382 See the docs for details. The docs were changed to clarify that
383 spawn functions return, and waitpid requires, a process handle on
384 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000385
Tim Peters11bd9942002-02-01 00:52:29 +0000386- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000387 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000388 to a nasty problem: before 2.3, if you got a temp file on Windows, it
389 got wrapped in an object whose close() method first closed the
390 underlying file, then deleted the file. This usually worked fine.
391 However, the spawn family of functions on Windows create (at a low C
392 level) the same set of open files in the spawned process Q as were
393 open in the spawning process P. If a temp file f was among them, then
394 doing f.close() in P first closed P's C-level file handle on f, but Q's
395 C-level file handle on f remained open, so the attempt in P to delete f
396 blew up with a "Permission denied" error (Windows doesn't allow
397 deleting open files). This was surprising, subtle, and difficult to
398 work around.
399
400- The os module now exports all the symbolic constants usable with the
401 low-level os.open() on Windows: the new constants in 2.3 are
402 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
403 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
404 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
405 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
406 (so specify both if you want both; note that neither is useful unless
407 specified with O_CREAT too).
408
Tim Petersaf8446f2001-12-21 21:36:50 +0000409Mac
410
411
Tim Peters909c0912001-12-14 23:16:18 +0000412What's New in Python 2.2 final?
413Release date: 21-Dec-2001
414===============================
415
416Type/class unification and new-style classes
417
Barry Warsaw52acb492001-12-21 20:04:22 +0000418- pickle.py, cPickle: allow pickling instances of new-style classes
419 with a custom metaclass.
420
Tim Peters909c0912001-12-14 23:16:18 +0000421Core and builtins
422
Barry Warsaw52acb492001-12-21 20:04:22 +0000423- weakref proxy object: when comparing, unwrap both arguments if both
424 are proxies.
425
Tim Peters909c0912001-12-14 23:16:18 +0000426Extension modules
427
Barry Warsaw52acb492001-12-21 20:04:22 +0000428- binascii.b2a_base64(): fix a potential buffer overrun when encoding
429 very short strings.
430
431- cPickle: the obscure "fast" mode was suspected of causing stack
432 overflows on the Mac. Hopefully fixed this by setting the recursion
433 limit much smaller. If the limit is too low (it only affects
434 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
435 when compiling cPickle.c (or in pyconfig.h).
436
Tim Peters909c0912001-12-14 23:16:18 +0000437Library
438
Barry Warsaw52acb492001-12-21 20:04:22 +0000439- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
440 close or delete time).
441
442- rfc822.py: fixed a bug where the address '<>' was converted to None
443 instead of an empty string (also fixes the email.Utils module).
444
445- xmlrpclib.py: version 1.0.0; uses precision for doubles.
446
447- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000448 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000449
Tim Peters909c0912001-12-14 23:16:18 +0000450Tools/Demos
451
452Build
453
454C API
455
456New platforms
457
458Tests
459
460Windows
461
Barry Warsaw52acb492001-12-21 20:04:22 +0000462- distutils package: fixed broken Windows installers (bdist_wininst).
463
464- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
465 instances are deleted at process exit time.
466
467- socket.py: prevent mysterious warnings when socket instances are
468 deleted at process exit time.
469
470- posixmodule.c: fix a Windows crash with stat() of a filename ending
471 in backslash.
472
Tim Peters909c0912001-12-14 23:16:18 +0000473Mac
474
Barry Warsaw52acb492001-12-21 20:04:22 +0000475- The Carbon toolbox modules have been upgraded to Universal Headers
476 3.4, and experimental CoreGraphics and CarbonEvents modules have
477 been added. All only for framework-enabled MacOSX.
478
Tim Peters909c0912001-12-14 23:16:18 +0000479
Tim Peters6272dfd2001-12-13 19:34:00 +0000480What's New in Python 2.2c1?
481Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000482===========================
483
484Type/class unification and new-style classes
485
Barry Warsaw06557452001-12-14 20:47:12 +0000486- Guido's tutorial introduction to the new type/class features has
487 been extensively updated. See
488
489 http://www.python.org/2.2/descrintro.html
490
491 That remains the primary documentation in this area.
492
Guido van Rossum33bab012001-12-05 22:45:48 +0000493- Fixed a leak: instance variables declared with __slots__ were never
494 deleted!
495
Guido van Rossum4b800852001-12-03 00:54:52 +0000496- The "delete attribute" method of descriptor objects is called
497 __delete__, not __del__. In previous releases, it was mistakenly
498 called __del__, which created an unfortunate overloading condition
499 with finalizers. (The "get attribute" and "set attribute" methods
500 are still called __get__ and __set__, respectively.)
501
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000502- Some subtle issues with the super built-in were fixed:
503
504 (a) When super itself is subclassed, its __get__ method would still
505 return an instance of the base class (i.e., of super).
506
507 (b) super(C, C()).__class__ would return C rather than super. This
508 is confusing. To fix this, I decided to change the semantics of
509 super so that it only applies to code attributes, not to data
510 attributes. After all, overriding data attributes is not
511 supported anyway.
512
513 (c) The __get__ method didn't check whether the argument was an
514 instance of the type used in creation of the super instance.
515
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000516- Previously, hash() of an instance of a subclass of a mutable type
517 (list or dictionary) would return some value, rather than raising
518 TypeError. This has been fixed. Also, directly calling
519 dict.__hash__ and list.__hash__ now raises the same TypeError
520 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000521
Guido van Rossumd331cb52001-12-05 19:46:42 +0000522- New-style objects now support deleting their __dict__. This is for
523 all intents and purposes equivalent to assigning a brand new empty
524 dictionary, but saves space if the object is not used further.
525
Tim Petersb3c9af12001-11-17 00:21:57 +0000526Core and builtins
527
Tim Peters3caca232001-12-06 06:23:26 +0000528- -Qnew now works as documented in PEP 238: when -Qnew is passed on
529 the command line, all occurrences of "/" use true division instead
530 of classic division. See the PEP for details. Note that "all"
531 means all instances in library and 3rd-party modules, as well as in
532 your own code. As the PEP says, -Qnew is intended for use only in
533 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000534 Note that test_coercion.py in the standard Python test suite fails
535 under -Qnew; this is expected, and won't be repaired until true
536 division becomes the default (in the meantime, test_coercion is
537 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000538
Fred Drake6c01e252001-12-14 17:08:12 +0000539- complex() now only allows the first argument to be a string
540 argument, and raises TypeError if either the second arg is a string
541 or if the second arg is specified when the first is a string.
542
Tim Petersb3c9af12001-11-17 00:21:57 +0000543Extension modules
544
Martin v. Löwis560da622001-11-24 09:24:51 +0000545- gc.get_referents was renamed to gc.get_referrers.
546
Tim Petersb3c9af12001-11-17 00:21:57 +0000547Library
548
Tim Peters25059d32001-12-07 20:35:43 +0000549- Functions in the os.spawn() family now release the global interpreter
550 lock around calling the platform spawn. They should always have done
551 this, but did not before 2.2c1. Multithreaded programs calling
552 an os.spawn function with P_WAIT will no longer block all Python threads
553 until the spawned program completes. It's possible that some programs
554 relies on blocking, although more likely by accident than by design.
555
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000556- webbrowser defaults to netscape.exe on OS/2 now.
557
Martin v. Löwis652e1912001-11-25 14:50:56 +0000558- Tix.ResizeHandle exposes detach_widget, hide, and show.
559
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000560- The charset alias windows_1252 has been added.
561
Barry Warsaw06557452001-12-14 20:47:12 +0000562- types.StringTypes is a tuple containing the defined string types;
563 usually this will be (str, unicode), but if Python was compiled
564 without Unicode support it will be just (str,).
565
566- The pulldom and minidom modules were synchronized to PyXML.
567
Tim Petersb3c9af12001-11-17 00:21:57 +0000568Tools/Demos
569
Barry Warsaw06557452001-12-14 20:47:12 +0000570- A new script called Tools/scripts/google.py was added, which fires
571 off a search on Google.
572
Tim Petersb3c9af12001-11-17 00:21:57 +0000573Build
574
Barry Warsaw06557452001-12-14 20:47:12 +0000575- Note that release builds of Python should arrange to define the
576 preprocessor symbol NDEBUG on the command line (or equivalent).
577 In the 2.2 pre-release series we tried to define this by magic in
578 Python.h instead, but it proved to cause problems for extension
579 authors. The Unix, Windows and Mac builds now all define NDEBUG in
580 release builds via cmdline (or equivalent) instead. Ports to
581 other platforms should do likewise.
582
Jack Jansen1999ef42001-12-06 21:47:20 +0000583- It is no longer necessary to use --with-suffix when building on a
584 case-insensitive file system (such as Mac OS X HFS+). In the build
585 directory an extension is used, but not in the installed python.
586
Tim Petersb3c9af12001-11-17 00:21:57 +0000587C API
588
Tim Petersf582b822001-12-11 18:51:08 +0000589- New function PyDict_MergeFromSeq2() exposes the builtin dict
590 constructor's logic for updating a dictionary from an iterable object
591 producing key-value pairs.
592
Tim Peterscffed4b2001-11-29 03:26:37 +0000593- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000594 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000595 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
596 dump core in some bad cases. This has been repaired. As a result,
597 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
598 previously went unchallenged.
599
Tim Petersb3c9af12001-11-17 00:21:57 +0000600New platforms
601
602Tests
603
604Windows
605
606Mac
607
Jack Jansenffa260f2001-12-06 21:14:00 +0000608- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
609 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000610
Barry Warsaw06557452001-12-14 20:47:12 +0000611- Changed logic for finding python home in Mac OS X framework Pythons.
612 Now sys.executable points to the executable again, in stead of to
613 the shared library. The latter is used only for locating the python
614 home.
615
616
Tim Peters84362bc2001-10-19 17:55:30 +0000617What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000618Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000619===========================
620
621Type/class unification and new-style classes
622
Guido van Rossum3d27df02001-11-15 20:27:54 +0000623- Multiple inheritance mixing new-style and classic classes in the
624 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000625
626 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000627 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000628
629 The MRO (method resolution order) for each base class is respected
630 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000631 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000632 This needs to be documented.
633
Tim Petersa427a2b2001-10-29 22:25:45 +0000634- The new builtin dictionary() constructor, and dictionary type, have
635 been renamed to dict. This reflects a decade of common usage.
636
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000637- dict() now accepts an iterable object producing 2-sequences. For
638 example, dict(d.items()) == d for any dictionary d. The argument,
639 and the elements of the argument, can be any iterable objects.
640
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000641- New-style classes can now have a __del__ method, which is called
642 when the instance is deleted (just like for classic classes).
643
Guido van Rossum12d955c2001-10-26 14:56:06 +0000644- Assignment to object.__dict__ is now possible, for objects that are
645 instances of new-style classes that have a __dict__ (unless the base
646 class forbids it).
647
Guido van Rossumc8e56452001-10-22 00:43:43 +0000648- Methods of built-in types now properly check for keyword arguments
649 (formerly these were silently ignored). The only built-in methods
650 that take keyword arguments are __call__, __init__ and __new__.
651
Guido van Rossum86443212001-10-27 22:28:54 +0000652- The socket function has been converted to a type; see below.
653
Tim Peters84362bc2001-10-19 17:55:30 +0000654Core and builtins
655
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000656- Assignment to __debug__ raises SyntaxError at compile-time. This
657 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000658 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000659
Guido van Rossum12d955c2001-10-26 14:56:06 +0000660- Clarified the error messages for unsupported operands to an operator
661 (like 1 + '').
662
Tim Peters84362bc2001-10-19 17:55:30 +0000663Extension modules
664
Tim Peters5ebfd362001-11-13 23:11:19 +0000665- mmap has a new keyword argument, "access", allowing a uniform way for
666 both Windows and Unix users to create read-only, write-through and
667 copy-on-write memory mappings. This was previously possible only on
668 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000669 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000670 platforms. Thanks to Jay T Miller for repairing this!
671
Tim Peters169ded02001-11-03 19:57:21 +0000672- By default, the gc.garbage list now contains only those instances in
673 unreachable cycles that have __del__ methods; in 2.1 it contained all
674 instances in unreachable cycles. "Instances" here has been generalized
675 to include instances of both new-style and old-style classes.
676
Guido van Rossum12d955c2001-10-26 14:56:06 +0000677- The socket module defines a new method for socket objects,
678 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000679 send() until all data has been sent. Also, the socket function has
680 been converted to a subclassable type, like list and tuple (etc.)
681 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000682
683- Various bugfixes to the curses module. There is now a test suite
684 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000685
Guido van Rossum692adf12001-10-30 03:03:03 +0000686- binascii.b2a_base64 no longer places an arbitrary restriction of 57
687 bytes on its input.
688
Tim Peters84362bc2001-10-19 17:55:30 +0000689Library
690
Tim Peters5ebfd362001-11-13 23:11:19 +0000691- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000692 convenience function.
693
Tim Peters75335872001-11-03 19:35:43 +0000694- Symbolic group names in regular expressions must be unique. For
695 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
696 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000697 Python 2.2 detects this error at regexp compilation time;
698 previously, the error went undetected, and results were
699 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
700 pattern.subn() methods have been rewritten in C. Also, an
701 experimental function/method finditer() has been added, which works
702 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000703
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000704- Tix exposes more commands through the classes DirSelectBox,
705 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
706 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
707 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
708
Tim Peters98791af2001-10-23 01:59:54 +0000709- Traceback objects are now scanned by cyclic garbage collection, so
710 cycles created by casual use of sys.exc_info() no longer cause
711 permanent memory leaks (provided garbage collection is enabled).
712
Guido van Rossum49192142001-10-24 20:51:44 +0000713- os.extsep -- a new variable needed by the RISCOS support. It is the
714 separator used by extensions, and is '.' on all platforms except
715 RISCOS, where it is '/'. There is no need to use this variable
716 unless you have a masochistic desire to port your code to RISCOS.
717
Barry Warsaw012852b2001-11-16 16:17:27 +0000718- mimetypes.py has optional support for non-standard, but commonly
719 found types. guess_type() and guess_extension() now accept an
720 optional `strict' flag, defaulting to true, which controls whether
721 recognize non-standard types or not. A few non-standard types we
722 know about have been added. Also, when run as a script, there are
723 new -l and -e options.
724
725- statcache is now deprecated.
726
727- email.Utils.formatdate() now produces the preferred RFC 2822 style
728 dates with numeric timezones (it used to produce obsolete dates
729 hard coded to "GMT" timezone). An optional `localtime' flag is
730 added to produce dates in the local timezone, with daylight savings
731 time properly taken into account.
732
733- In pickle and cPickle, instead of masking errors in load() by
734 transforming them into SystemError, we let the original exception
735 propagate out. Also, implement support for __safe_for_unpickling__
736 in pickle, as it already was supported in cPickle.
737
Tim Peters84362bc2001-10-19 17:55:30 +0000738Tools/Demos
739
740Build
741
Barry Warsaw012852b2001-11-16 16:17:27 +0000742- The dbm module is built using libdb1 if available. The bsddb module
743 is built with libdb3 if available.
744
745- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
746
Tim Peters84362bc2001-10-19 17:55:30 +0000747C API
748
Tim Peters1fc240e2001-10-26 05:06:50 +0000749- New function PySequence_Fast_GET_SIZE() returns the size of a non-
750 NULL result from PySequence_Fast(), more quickly than calling
751 PySequence_Size().
752
Barry Warsaw012852b2001-11-16 16:17:27 +0000753- New argument unpacking function PyArg_UnpackTuple() added.
754
755- New functions PyObject_CallFunctionObjArgs() and
756 PyObject_CallMethodObjArgs() have been added to make it more
757 convenient and efficient to call functions and methods from C.
758
759- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
760 possible that this will propagate errors it didn't before.
761
762- New function PyObject_CheckReadBuffer(), which returns true if its
763 argument supports the single-segment readable buffer interface.
764
Tim Peters84362bc2001-10-19 17:55:30 +0000765New platforms
766
Guido van Rossum86443212001-10-27 22:28:54 +0000767- We've finally confirmed that this release builds on HP-UX 11.00,
768 *with* threads, and passes the test suite.
769
Tim Peters7a33d8b2001-11-05 02:51:07 +0000770- Thanks to a series of patches from Michael Muller, Python may build
771 again under OS/2 Visual Age C++.
772
Guido van Rossum49192142001-10-24 20:51:44 +0000773- Updated RISCOS port by Dietmar Schwertberger.
774
Tim Peters84362bc2001-10-19 17:55:30 +0000775Tests
776
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000777- Added a test script for the curses module. It isn't run automatically;
778 regrtest.py must be run with '-u curses' to enable it.
779
Tim Peters84362bc2001-10-19 17:55:30 +0000780Windows
781
Barry Warsaw012852b2001-11-16 16:17:27 +0000782Mac
783
784- PythonScript has been moved to unsupported and is slated to be
785 removed completely in the next release.
786
787- It should now be possible to build applets that work on both OS9 and
788 OSX.
789
790- The core is now linked with CoreServices not Carbon; as a side
791 result, default 8bit encoding on OSX is now ASCII.
792
793- Python should now build on OSX 10.1.1
794
Tim Peters84362bc2001-10-19 17:55:30 +0000795
Tim Petersabf925f2001-09-28 21:53:42 +0000796What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000797Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000798===========================
799
800Type/class unification and new-style classes
801
Guido van Rossum687ae002001-10-15 22:03:32 +0000802- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000803 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000804 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000805 remains: the __dict__ of a new-style class is a read-only proxy; you
806 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000807 __defined__ attribute of new-style types no longer exists, for lack
808 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000809 future a __cache__ may be resurrected with a similar function, if I
810 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000811
Tim Peters1c9ca872001-10-04 06:43:12 +0000812- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
813 always returned None, even when there was a class docstring).
814
815- doctest now finds and runs docstrings attached to new-style classes,
816 class methods, static methods, and properties.
817
Guido van Rossum9074ef62001-10-16 21:34:49 +0000818Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000819
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000820- A very subtle syntactical pitfall in list comprehensions was fixed.
821 For example: [a+b for a in 'abc', for b in 'def']. The comma in
822 this example is a mistake. Previously, this would silently let 'a'
823 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
824 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
825 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
826 Note that [a for a in <singleton>] is a convoluted way to say
827 [<singleton>] anyway, so it's not like any expressiveness is lost.
828
Guido van Rossum9074ef62001-10-16 21:34:49 +0000829- getattr(obj, name, default) now only catches AttributeError, as
830 documented, rather than returning the default value for all
831 exceptions (which could mask bugs in a __getattr__ hook, for
832 example).
833
Fred Drakecb7a6b52001-10-22 18:41:51 +0000834- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000835 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000836 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000837 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000838
Guido van Rossum1c486092001-10-19 02:05:35 +0000839- unicode(obj) now behaves more like str(obj), accepting arbitrary
840 objects, and calling a __unicode__ method if it exists.
841 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000842 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000843
Barry Warsawf6fb1712001-10-19 05:35:40 +0000844- isinstance() now allows any object as the first argument and a
845 class, a type or something with a __bases__ tuple attribute for the
846 second argument. The second argument may also be a tuple of a
847 class, type, or something with __bases__, in which case isinstance()
848 will return true if the first argument is an instance of any of the
849 things contained in the second argument tuple. E.g.
850
851 isinstance(x, (A, B))
852
853 returns true if x is an instance of A or B.
854
Guido van Rossum9074ef62001-10-16 21:34:49 +0000855Extension modules
856
857- thread.start_new_thread() now returns the thread ID (previously None).
858
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000859- binascii has now two quopri support functions, a2b_qp and b2a_qp.
860
Guido van Rossumc524d952001-10-19 01:31:59 +0000861- readline now supports setting the startup_hook and the
862 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000863
Guido van Rossumc524d952001-10-19 01:31:59 +0000864- os and posix supports chroot(), setgroups() and unsetenv() where
865 available. The stat(), fstat(), statvfs() and fstatvfs() functions
866 now return "pseudo-sequences" -- the various fields can now be
867 accessed as attributes (e.g. os.stat("/").st_mtime) but for
868 backwards compatibility they also behave as a fixed-length sequence.
869 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000870 attributes.
871
872- time: localtime(), gmtime() and strptime() now return a
873 pseudo-sequence similar to the os.stat() return value, with
874 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000875
Guido van Rossum9074ef62001-10-16 21:34:49 +0000876- Decompression objects in the zlib module now accept an optional
877 second parameter to decompress() that specifies the maximum amount
878 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000879
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000880- optional SSL support in the socket module now exports OpenSSL
881 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
882 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000883 automatically seed its PRNG. Also, the keyfile and certfile
884 arguments to socket.ssl() are now optional.
885
886- posixmodule (and by extension, the os module on POSIX platforms) now
887 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000888
Guido van Rossum9074ef62001-10-16 21:34:49 +0000889Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000890
Tim Peters7402f792001-10-02 03:53:41 +0000891- doctest now excludes functions and classes not defined by the module
892 being tested, thanks to Tim Hochberg.
893
Fred Drakecb7a6b52001-10-22 18:41:51 +0000894- HotShot, a new profiler implemented using a C-based callback, has
895 been added. This substantially reduces the overhead of profiling,
896 but it is still quite preliminary. Support modules and
897 documentation will be added in upcoming releases (before 2.2 final).
898
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000899- profile now produces correct output in situations where an exception
900 raised in Python is cleared by C code (e.g. hasattr()). This used
901 to cause wrong output, including spurious claims of recursive
902 functions and attribution of time spent to the wrong function.
903
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000904 The code and documentation for the derived OldProfile and HotProfile
905 profiling classes was removed. The code hasn't worked for years (if
906 you tried to use them, they raised exceptions). OldProfile
907 intended to reproduce the behavior of the profiler Python used more
908 than 7 years ago, and isn't interesting anymore. HotProfile intended
909 to provide a faster profiler (but producing less information), and
910 that's a worthy goal we intend to meet via a different approach (but
911 without losing information).
912
Tim Peterscce092d2001-10-09 05:31:56 +0000913- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000914 a much better system-specific calibration constant. The constant can
915 now be specified in an instance constructor, or as a Profile class or
916 instance variable, instead of by editing profile.py's source code.
917 Calibration must still be done manually (see the docs for the profile
918 module).
919
920 Note that Profile.calibrate() must be overriden by subclasses.
921 Improving the accuracy required exploiting detailed knowledge of
922 profiler internals; the earlier method abstracted away the details
923 and measured a simplified model instead, but consequently computed
924 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000925
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000926- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000927 which indicates whether output is intended for the header 'Q'
928 encoding.
929
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000930- The SocketServer.ThreadingMixIn class now closes the request after
931 finish_request() returns. (Not when it errors out though.)
932
Barry Warsawf6fb1712001-10-19 05:35:40 +0000933- The nntplib module's NNTP.body() method has grown a `file' argument
934 to allow saving the message body to a file.
935
936- The email package has added a class email.Parser.HeaderParser which
937 only parses headers and does not recurse into the message's body.
938 Also, the module/class MIMEAudio has been added for representing
939 audio data (contributed by Anthony Baxter).
940
941- ftplib should be able to handle files > 2GB.
942
943- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
944 ON, and OFF.
945
Fred Drakecb7a6b52001-10-22 18:41:51 +0000946- xml.dom.minidom NodeList objects now support the length attribute
947 and item() method as required by the DOM specifications.
948
Guido van Rossumed554f62001-10-02 23:15:37 +0000949Tools/Demos
950
951- Demo/dns was removed. It no longer serves any purpose; a package
952 derived from it is now maintained by Anthony Baxter, see
953 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000954
Barry Warsawf6fb1712001-10-19 05:35:40 +0000955- The freeze tool has been made more robust, and two new options have
956 been added: -X and -E.
957
Tim Petersabf925f2001-09-28 21:53:42 +0000958Build
959
Barry Warsawf6fb1712001-10-19 05:35:40 +0000960- configure will use CXX in LINKCC if CXX is used to build main() and
961 the system requires to link a C++ main using the C++ compiler.
962
Tim Petersabf925f2001-09-28 21:53:42 +0000963C API
964
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000965- The documentation for the tp_compare slot is updated to require that
966 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
967 not correct. This is not yet enforced but will be enforced in
968 Python 2.3; even later, we may use -2 to indicate errors and +2 for
969 "NotImplemented". Right now, -1 should be used for an error return.
970
Tim Petersd38b1c72001-09-30 05:09:37 +0000971- PyLong_AsLongLong() now accepts int (as well as long) arguments.
972 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
973 as long) arguments.
974
Guido van Rossum3c288632001-10-16 21:13:49 +0000975- PyThread_start_new_thread() now returns a long int giving the thread
976 ID, if one can be calculated; it returns -1 for error, 0 if no
977 thread ID is calculated (this is an incompatible change, but only
978 the thread module used this API). This code has only really been
979 tested on Linux and Windows; other platforms please beware (and
980 report any bugs or strange behavior).
981
Guido van Rossum1c486092001-10-19 02:05:35 +0000982- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
983 input.
984
Tim Petersabf925f2001-09-28 21:53:42 +0000985New platforms
986
987Tests
988
989Windows
990
Tim Peters04cf1d32001-10-09 22:39:40 +0000991- Installer: If you install IDLE, and don't disable file-extension
992 registration, a new "Edit with IDLE" context (right-click) menu entry
993 is created for .py and .pyw files.
994
Tim Peters1ce3cf72001-10-01 17:58:40 +0000995- The signal module now supports SIGBREAK on Windows, thanks to Steven
996 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
997 action remains to call Win32 ExitProcess(). This can be changed via
998 signal.signal(). For example:
999
1000 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1001 # (SIGINT) behavior.
1002 import signal
1003 signal.signal(signal.SIGBREAK,
1004 signal.default_int_handler)
1005
1006 try:
1007 while 1:
1008 pass
1009 except KeyboardInterrupt:
1010 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1011 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1012 # program without the possibility for any Python-level cleanup).
1013 print "Clean exit"
1014
Tim Petersabf925f2001-09-28 21:53:42 +00001015
Tim Petersb07352e2001-09-08 01:25:47 +00001016What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001017Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001018===========================
1019
Guido van Rossum808eea72001-09-25 04:15:41 +00001020Type/class unification and new-style classes
1021
1022- pydoc and inspect are now aware of new-style classes;
1023 e.g. help(list) at the interactive prompt now shows proper
1024 documentation for all operations on list objects.
1025
1026- Applications using Jim Fulton's ExtensionClass module can now safely
1027 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1028 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1029 examples also work again. It is hoped that Gtk and Boost also work
1030 with 2.2a4 and beyond. (If you can confirm this, please write
1031 webmaster@python.org; if there are still problems, please open a bug
1032 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001033
Tim Peters66c1a522001-09-24 21:17:50 +00001034- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001035 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001036 in the constructed property object. fget, fset and fdel weren't
1037 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1038 associate a docstring with a property.
1039
Guido van Rossum808eea72001-09-25 04:15:41 +00001040- Comparison overloading is now more completely implemented. For
1041 example, a str subclass instance can properly be compared to a str
1042 instance, and it can properly overload comparison. Ditto for most
1043 other built-in object types.
1044
1045- The repr() of new-style classes has changed; instead of <type
1046 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1047 *except* for built-in types, which are still rendered as <type
1048 'Foo'> (to avoid upsetting existing code that might parse or
1049 otherwise rely on repr() of certain type objects).
1050
1051- The repr() of new-style objects is now always <Foo object at XXX>;
1052 previously, it was sometimes <Foo instance at XXX>.
1053
1054- For new-style classes, what was previously called __getattr__ is now
1055 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001056 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001057 one in classic classes is defined which is called only if regular
1058 attribute access raises AttributeError; to catch *all* attribute
1059 access, you can use __getattribute__ (for new-style classes). If
1060 both are defined, __getattribute__ is called first, and if it raises
1061 AttributeError, __getattr__ is called.
1062
1063- The __class__ attribute of new-style objects can be assigned to.
1064 The new class must have the same C-level object layout as the old
1065 class.
1066
1067- The builtin file type can be subclassed now. In the usual pattern,
1068 "file" is the name of the builtin type, and file() is a new builtin
1069 constructor, with the same signature as the builtin open() function.
1070 file() is now the preferred way to open a file.
1071
1072- Previously, __new__ would only see sequential arguments passed to
1073 the type in a constructor call; __init__ would see both sequential
1074 and keyword arguments. This made no sense whatsoever any more, so
1075 now both __new__ and __init__ see all arguments.
1076
1077- Previously, hash() applied to an instance of a subclass of str or
1078 unicode always returned 0. This has been repaired.
1079
1080- Previously, an operation on an instance of a subclass of an
1081 immutable type (int, long, float, complex, tuple, str, unicode),
1082 where the subtype didn't override the operation (and so the
1083 operation was handled by the builtin type), could return that
1084 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001085 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001086 with the same value as s.
1087
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001088- Provisional support for pickling new-style objects has been added.
1089
Guido van Rossum808eea72001-09-25 04:15:41 +00001090Core
1091
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001092- file.writelines() now accepts any iterable object producing strings.
1093
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001094- PyUnicode_FromEncodedObject() now works very much like
1095 PyObject_Str(obj) in that it tries to use __str__/tp_str
1096 on the object if the object is not a string or buffer. This
1097 makes unicode() behave like str() when applied to non-string/buffer
1098 objects.
1099
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001100- PyFile_WriteObject now passes Unicode objects to the file's write
1101 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001102 of a print statement must support Unicode objects, i.e. they must
1103 at least convert them into ASCII strings.
1104
Guido van Rossum624c8af2001-09-18 15:21:04 +00001105- Thread scheduling on Solaris should be improved; it is no longer
1106 necessary to insert a small sleep at the start of a thread in order
1107 to let other runnable threads be scheduled.
1108
Tim Petersb07352e2001-09-08 01:25:47 +00001109Library
1110
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001111- StringIO.StringIO instances and cStringIO.StringIO instances support
1112 read character buffer compatible objects for their .write() methods.
1113 These objects are converted to strings and then handled as such
1114 by the instances.
1115
Barry Warsaw2f600732001-09-24 04:28:10 +00001116- The "email" package has been added. This is basically a port of the
1117 mimelib package <http://sf.net/projects/mimelib> with API changes
1118 and some implementations updated to use iterators and generators.
1119
Tim Peters8a9c2842001-09-22 21:30:22 +00001120- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1121 restores the ability of Tools/scripts/ndiff.py to start producing output
1122 before the entire comparison is complete.
1123
Barry Warsaw58b072d2001-09-22 04:44:21 +00001124- StringIO.StringIO instances and cStringIO.StringIO instances support
1125 iteration just like file objects (i.e. their .readline() method is
1126 called for each iteration until it returns an empty string).
1127
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001128- The codecs module has grown four new helper APIs to access
1129 builtin codecs: getencoder(), getdecoder(), getreader(),
1130 getwriter().
1131
Guido van Rossum624c8af2001-09-18 15:21:04 +00001132- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1133 simplifies writing XML RPC servers.
1134
Barry Warsaw647d5e82001-09-28 17:01:02 +00001135- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001136 after interpretation of symbolic links. On non-Unix systems, this
1137 is an alias for os.path.abspath().
1138
Tim Peters16a77ad2001-09-08 04:00:12 +00001139- operator.indexOf() (PySequence_Index() in the C API) now works with any
1140 iterable object.
1141
Guido van Rossum624c8af2001-09-18 15:21:04 +00001142- smtplib now supports various authentication and security features of
1143 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001144
Guido van Rossum624c8af2001-09-18 15:21:04 +00001145- hmac: a new module implementing keyed hashing for message
1146 authentication.
1147
1148- mimetypes now recognizes more extensions and file types. At the
1149 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001150
Guido van Rossum624c8af2001-09-18 15:21:04 +00001151- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001152 Python 2.2 bytecode generation. It has also been promoted from a
1153 Tool to a standard library package. (Tools/compiler still exists as
1154 a sample driver.)
1155
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001156Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001157
Tim Petersb07352e2001-09-08 01:25:47 +00001158Build
1159
Guido van Rossum624c8af2001-09-18 15:21:04 +00001160- Large file support (LFS) is now automatic when the platform supports
1161 it; no more manual configuration tweaks are needed. On Linux, at
1162 least, it's possible to have a system whose C library supports large
1163 files but whose kernel doesn't; in this case, large file support is
1164 still enabled but doesn't do you any good unless you upgrade your
1165 kernel or share your Python executable with another system whose
1166 kernel has large file support.
1167
1168- The configure script now supplies plausible defaults in a
1169 cross-compilation environment. This doesn't mean that the supplied
1170 values are always correct, or that cross-compilation now works
1171 flawlessly -- but it's a first step (and it shuts up most of
1172 autoconf's warnings about AC_TRY_RUN).
1173
1174- The Unix build is now a bit less chatty, courtesy of the parser
1175 generator. The build is completely silent (except for errors) when
1176 using "make -s", thanks to a -q option to setup.py.
1177
Tim Petersb07352e2001-09-08 01:25:47 +00001178C API
1179
Guido van Rossum624c8af2001-09-18 15:21:04 +00001180- The "structmember" API now supports some new flag bits to deny read
1181 and/or write access to attributes in restricted execution mode.
1182
Tim Petersb07352e2001-09-08 01:25:47 +00001183New platforms
1184
Guido van Rossum624c8af2001-09-18 15:21:04 +00001185- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1186 (http://familiar.handhelds.org).
1187
Tim Petersb07352e2001-09-08 01:25:47 +00001188Tests
1189
Tim Peters8a9c2842001-09-22 21:30:22 +00001190- The "classic" standard tests, which work by comparing stdout to
1191 an expected-output file under Lib/test/output/, no longer stop at
1192 the first mismatch. Instead the test is run to completion, and a
1193 variant of ndiff-style comparison is used to report all differences.
1194 This is much easier to understand than the previous style of reporting.
1195
1196- The unittest-based standard tests now use regrtest's test_main()
1197 convention, instead of running as a side-effect of merely being
1198 imported. This allows these tests to be run in more natural and
1199 flexible ways as unittests, outside the regrtest framework.
1200
1201- regrtest.py is much better integrated with unittest and doctest now,
1202 especially in regard to reporting errors.
1203
Tim Petersb07352e2001-09-08 01:25:47 +00001204Windows
1205
Guido van Rossum624c8af2001-09-18 15:21:04 +00001206- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001207 that support it (NTFS under Windows 2000). See "What's New in
1208 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001209
Tim Petersb07352e2001-09-08 01:25:47 +00001210
Tim Petersedc99312001-08-22 21:36:50 +00001211What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001212Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001213===========================
1214
1215Core
1216
Tim Peters9fffa3e2001-09-04 05:14:19 +00001217- Conversion of long to float now raises OverflowError if the long is too
1218 big to represent as a C double.
1219
Tim Peters32f453e2001-09-03 08:35:41 +00001220- The 3-argument builtin pow() no longer allows a third non-None argument
1221 if either of the first two arguments is a float, or if both are of
1222 integer types and the second argument is negative (in which latter case
1223 the arguments are converted to float, so this is really the same
1224 restriction).
1225
Tim Peters5d2b77c2001-09-03 05:47:38 +00001226- The builtin dir() now returns more information, and sometimes much
1227 more, generally naming all attributes of an object, and all attributes
1228 reachable from the object via its class, and from its class's base
1229 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1230 an empty list. In 2.2a3,
1231
1232 >>> dir([])
1233 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1234 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1235 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1236 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1237 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1238 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1239 'reverse', 'sort']
1240
1241 dir(module) continues to return only the module's attributes, though.
1242
Tim Petersbdee63f2001-09-02 03:40:59 +00001243- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001244 than raising OverflowError. This is a partial implementation of PEP
1245 237. You can use -Wdefault::OverflowWarning to enable a warning for
1246 this situation, and -Werror::OverflowWarning to revert to the old
1247 OverflowError exception.
1248
Guido van Rossum61c345f2001-09-04 03:26:15 +00001249- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001250 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001251 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1252 -Qold, meaning the / operator has its classic meaning and no
1253 warnings are issued. Using -Qwarn issues a run-time warning about
1254 all uses of classic division for int and long arguments; -Qwarnall
1255 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001256 (for use with fixdiv.py).
1257 [Note: the remainder of this paragraph (preserved below) became
1258 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1259 <obsolete>
1260 Using -Qnew is questionable; it turns on new division by default, but
1261 only in the __main__ module. You can usefully combine -Qwarn or
1262 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1263 warns about classic division everywhere else.
1264 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001265
Tim Petersbdee63f2001-09-02 03:40:59 +00001266- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001267 long, float, str, unicode, and tuple. (The types complex, list and
1268 dictionary can also be subclassed; this was introduced earlier.)
1269 Note that restrictions apply when subclassing immutable built-in
1270 types: you can only affect the value of the instance by overloading
1271 __new__. You can add mutable attributes, and the subclass instances
1272 will have a __dict__ attribute, but you cannot change the "value"
1273 (as implemented by the base class) of an immutable subclass instance
1274 once it is created.
1275
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001276- The dictionary constructor now takes an optional argument, a
1277 mapping-like object, and initializes the dictionary from its
1278 (key, value) pairs.
1279
Tim Petersbdee63f2001-09-02 03:40:59 +00001280- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001281 "cooperative super calls" in a multiple inheritance setting. For an
1282 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1283
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001284- A new built-in type, property, has been added. This enables the
1285 creation of "properties". These are attributes implemented by
1286 getter and setter functions (or only one of these for read-only or
1287 write-only attributes), without the need to override __getattr__.
1288 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001289
Tim Petersbdee63f2001-09-02 03:40:59 +00001290- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001291 liberalized, to allow leading zeroes. Examples of literals now
1292 legal that were SyntaxErrors before:
1293
1294 00.0 0e3 0100j 07.5 00000000000000000008.
1295
Tim Petersbdee63f2001-09-02 03:40:59 +00001296- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001297 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1298
Tim Petersedc99312001-08-22 21:36:50 +00001299Library
1300
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001301- telnetlib includes symbolic names for the options, and support for
1302 setting an option negotiation callback.
1303
Tim Petersa40c7932001-09-05 22:36:56 +00001304- The new C standard no longer requires that math libraries set errno to
1305 ERANGE on overflow. For platform libraries that exploit this new
1306 freedom, Python's overflow-checking was wholly broken. A new overflow-
1307 checking scheme attempts to repair that, but may not be reliable on all
1308 platforms (C doesn't seem to provide anything both useful and portable
1309 in this area anymore).
1310
Martin v. Löwis44f86962001-09-05 13:44:54 +00001311- Asynchronous timeout actions are available through the new class
1312 threading.Timer.
1313
Tim Peters78526162001-09-05 00:53:45 +00001314- math.log and math.log10 now return sensible results for even huge
1315 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1316
Tim Petersbdee63f2001-09-02 03:40:59 +00001317- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001318 currently held. See the docs for the imp module.
1319
Tim Petersbdee63f2001-09-02 03:40:59 +00001320- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001321 dumps containing ints written on platforms where Python ints are 8 bytes.
1322 When read on a box where Python ints are 4 bytes, such values are
1323 converted to Python longs.
1324
Tim Petersbdee63f2001-09-02 03:40:59 +00001325- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001326 code objects is no longer allowed. This plugs a security hole.
1327
Steve Purcell6091cd62001-09-06 16:05:17 +00001328- unittest.TestResult instances no longer store references to tracebacks
1329 generated by test failures. This prevents unexpected dangling references
1330 to objects that should be garbage collected between tests.
1331
Tim Petersedc99312001-08-22 21:36:50 +00001332Tools
1333
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001334- Tools/scripts/fixdiv.py has been added which can be used to fix
1335 division operators as per PEP 238.
1336
Tim Petersedc99312001-08-22 21:36:50 +00001337Build
1338
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001339- If you are an adventurous person using Mac OS X you may want to look at
1340 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1341 application, which can be used for experimenting with Carbon or Cocoa.
1342 Discussion of this on pythonmac-sig, please.
1343
Tim Peters7eea37e2001-09-04 22:08:56 +00001344C API
1345
1346- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001347
Tim Peters9fffa3e2001-09-04 05:14:19 +00001348- Note that PyLong_AsDouble can fail! This has always been true, but no
1349 callers checked for it. It's more likely to fail now, because overflow
1350 errors are properly detected now. The proper way to check:
1351
1352 double x = PyLong_AsDouble(some_long_object);
1353 if (x == -1.0 && PyErr_Occurred()) {
1354 /* The conversion failed. */
1355 }
1356
Tim Petersbdee63f2001-09-02 03:40:59 +00001357- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001358 compile but will not participate in GC. To upgrade an extension
1359 module:
1360
1361 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001362
Neil Schemenauer4042c692001-08-30 15:38:01 +00001363 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1364 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001365
Neil Schemenauer4042c692001-08-30 15:38:01 +00001366 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1367 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001368
Neil Schemenauer4042c692001-08-30 15:38:01 +00001369 - remove PyGC_HEAD_SIZE from object size calculations
1370
1371 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1372
Tim Petersbdee63f2001-09-02 03:40:59 +00001373- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001374 These can be used safely to construct string objects from a
1375 sprintf-style format string (similar to the format string supported
1376 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001377
Tim Petersedc99312001-08-22 21:36:50 +00001378New platforms
1379
Tim Petersb7da0902001-09-02 23:01:43 +00001380- Stephen Hansen contributed patches sufficient to get a clean compile
1381 under Borland C (Windows), but he reports problems running it and ran
1382 out of time to complete the port. Volunteers? Expect a MemoryError
1383 when importing the types module; this is probably shallow, and
1384 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001385
Tim Petersedc99312001-08-22 21:36:50 +00001386Tests
1387
1388Windows
1389
Tim Peters6e13a562001-09-06 00:32:15 +00001390- Large file support is now enabled on Win32 platforms as well as on
1391 Win64. This means that, for example, you can use f.tell() and f.seek()
1392 to manipulate files larger than 2 gigabytes (provided you have enough
1393 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001394 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1395 filesize limit, and large file support makes no difference there.
1396 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1397 NTFS has no practical limit on file size, and files of any size can be
1398 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001399
Tim Petersbdee63f2001-09-02 03:40:59 +00001400- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001401 points to command.com (patch from Brian Quinlan).
1402
Tim Petersedc99312001-08-22 21:36:50 +00001403
Tim Peters20f51a72001-07-21 02:31:40 +00001404What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001405Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001406===========================
1407
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001408Build
1409
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001410- Tim Peters developed a brand new Windows installer using Wise 8.1,
1411 generously donated to us by Wise Solutions.
1412
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001413- configure supports a new option --enable-unicode, with the values
1414 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1415 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001416
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001417- A new configure option --enable-framework builds a Mac OS X framework,
1418 which "make frameworkinstall" will install. This provides a starting
1419 point for more mac-like functionality, join pythonmac-sig@python.org
1420 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001421
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001422- The NeXT platform is no longer supported.
1423
1424- The `new' module is now statically linked.
1425
Tim Peters0afb6092001-08-15 06:06:44 +00001426Tools
1427
1428- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001429 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001430 the module docstring for details.
1431
Tim Peters20f51a72001-07-21 02:31:40 +00001432Tests
1433
Tim Peters5e824c32001-08-12 22:25:01 +00001434- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001435 platforms, allowing to give clearer test result output. regrtest
1436 also has optional --use/-u switch to run normally disabled tests
1437 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001438
Tim Peters20f51a72001-07-21 02:31:40 +00001439- Several new tests in the standard test suite, with special thanks to
1440 Nick Mathewson.
1441
1442Core
1443
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001444- The floor division operator // has been added as outlined in PEP
1445 238. The / operator still provides classic division (and will until
1446 Python 3.0) unless "from __future__ import division" is included, in
1447 which case the / operator will provide true division. The operator
1448 module provides truediv() and floordiv() functions. Augmented
1449 assignment variants are included, as are the equivalent overloadable
1450 methods and C API methods. See the PEP for a full discussion:
1451 <http://python.sf.net/peps/pep-0238.html>
1452
Tim Peters6cd6a822001-08-17 22:11:27 +00001453- Future statements are now effective in simulated interactive shells
1454 (like IDLE). This should "just work" by magic, but read Michael
1455 Hudson's "Future statements in simulated shells" PEP 264 for full
1456 details: <http://python.sf.net/peps/pep-0264.html>.
1457
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001458- The type/class unification (PEP 252-253) was integrated into the
1459 trunk and is not so tentative any more (the exact specification of
1460 some features is still tentative). A lot of work has done on fixing
1461 bugs and adding robustness and features (performance still has to
1462 come a long way).
1463
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001464- Warnings about a mismatch in the Python API during extension import
1465 now use the Python warning framework (which makes it possible to
1466 write filters for these warnings).
1467
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001468- A function's __dict__ (aka func_dict) will now always be a
1469 dictionary. It used to be possible to delete it or set it to None,
1470 but now both actions raise TypeErrors. It is still legal to set it
1471 to a dictionary object. Getting func.__dict__ before any attributes
1472 have been assigned now returns an empty dictionary instead of None.
1473
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001474- A new command line option, -E, was added which disables the use of
1475 all environment variables, or at least those that are specifically
1476 significant to Python. Usually those have a name starting with
1477 "PYTHON". This was used to fix a problem where the tests fail if
1478 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1479 older distribution.
1480
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001481Library
1482
Tim Peters5e824c32001-08-12 22:25:01 +00001483- New class Differ and new functions ndiff() and restore() in difflib.py.
1484 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001485 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001486
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001487- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1488 value using the minimal quoting required for the value; more
1489 reliable than using xml.sax.saxutils.escape() for attribute values.
1490
1491- Readline completion support for cmd.Cmd was added.
1492
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001493- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1494
1495- Added function threading.BoundedSemaphore()
1496
1497- Added Ka-Ping Yee's cgitb.py module.
1498
1499- The `new' module now exposes the CO_xxx flags.
1500
Martin v. Löwis560da622001-11-24 09:24:51 +00001501- The gc module offers the get_referents function.
1502
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001503New platforms
1504
1505C API
1506
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001507- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1508 which provide a cross-platform implementations for the
1509 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1510 the standard sprintf() and vsprintf() C lib APIs, these versions
1511 apply bounds checking on the used buffer which enhances protection
1512 against buffer overruns.
1513
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001514- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001515 and extensions using different Unicode widths is rendered next to
1516 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001517 will result in an ImportError. Unicode extensions writers must make
1518 sure to check the Unicode width compatibility in their extensions by
1519 using at least one of the mangled Unicode APIs in the extension.
1520
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001521- Two new flags METH_NOARGS and METH_O are available in method definition
1522 tables to simplify implementation of methods with no arguments and a
1523 single untyped argument. Calling such methods is more efficient than
1524 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1525 deprecated.
1526
Tim Petersc1731372001-08-04 08:12:36 +00001527Windows
1528
1529- "import module" now compiles module.pyw if it exists and nothing else
1530 relevant is found.
1531
Tim Peters20f51a72001-07-21 02:31:40 +00001532
Guido van Rossum55a78992001-07-17 17:22:32 +00001533What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001534Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001535===========================
1536
1537Core
Tim Petersa814db52001-05-14 07:05:58 +00001538
Tim Peters6d6c1a32001-08-02 04:15:00 +00001539- TENTATIVELY, a large amount of code implementing much of what's
1540 described in PEP 252 (Making Types Look More Like Classes) and PEP
1541 253 (Subtyping Built-in Types) was added. This will be released
1542 with Python 2.2a1. Documentation will be provided separately
1543 through http://www.python.org/2.2/. The purpose of releasing this
1544 with Python 2.2a1 is to test backwards compatibility. It is
1545 possible, though not likely, that a decision is made not to release
1546 this code as part of 2.2 final, if any serious backwards
1547 incompapatibilities are found during alpha testing that cannot be
1548 repaired.
1549
Guido van Rossum55a78992001-07-17 17:22:32 +00001550- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001551 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001552 more 'yield' statements. See PEP 255. Since this adds a new
1553 keyword to the language, this feature must be enabled by including a
1554 future statement: "from __future__ import generators" (see PEP 236).
1555 Generators will become a standard feature in a future release
1556 (probably 2.3). Without this future statement, 'yield' remains an
1557 ordinary identifier, but a warning is issued each time it is used.
1558 (These warnings currently don't conform to the warnings framework of
1559 PEP 230; we intend to fix this in 2.2a2.)
1560
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001561- The UTF-16 codec was modified to be more RFC compliant. It will now
1562 only remove BOM characters at the start of the string and then
1563 only if running in native mode (UTF-16-LE and -BE won't remove a
1564 leading BMO character).
1565
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001566- Strings now have a new method .decode() to complement the already
1567 existing .encode() method. These two methods provide direct access
1568 to the corresponding decoders and encoders of the registered codecs.
1569
1570 To enhance the usability of the .encode() method, the special
1571 casing of Unicode object return values was dropped (Unicode objects
1572 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001573
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001574 Both methods will now return whatever the codec in charge of the
1575 requested encoding returns as object, e.g. Unicode codecs will
1576 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1577 will return u"äöü"). This enables codec writer to create codecs
1578 for various simple to use conversions.
1579
1580 New codecs were added to demonstrate these new features (the .encode()
1581 and .decode() columns indicate the type of the returned objects):
1582
1583 Name | .encode() | .decode() | Description
1584 ----------------------------------------------------------------------
1585 uu | string | string | UU codec (e.g. for email)
1586 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001587 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001588 zlib | string | string | zlib compression
1589 hex | string | string | 2-byte hex codec
1590 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1591
Mark Hammond2a0af792001-05-14 03:09:36 +00001592- Some operating systems now support the concept of a default Unicode
1593 encoding for file system operations. Notably, Windows supports 'mbcs'
1594 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001595 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001596 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001597
1598 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001599 functions that return filenames (such as os.listdir()) to return Python
1600 string objects pre-encoded using the default file system encoding for
1601 the platform. As this encoding is likely to be different from Python's
1602 default encoding, converting this name to a Unicode object before passing
1603 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001604 would attempt to use its default encoding (generally ASCII) rather than
1605 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001606
Tim Petersa814db52001-05-14 07:05:58 +00001607 In general, this change simply removes surprises when working with
1608 Unicode and the file system, making these operations work as you expect,
1609 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001610 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001611
Tim Peters61dff2b2001-05-08 15:43:37 +00001612- Float (and complex) literals in source code were evaluated to full
1613 precision only when running from a .py file; the same code loaded from a
1614 .pyc (or .pyo) file could suffer numeric differences starting at about the
1615 12th significant decimal digit. For example, on a machine with IEEE-754
1616 floating arithmetic,
1617
1618 x = 9007199254740992.0
1619 print long(x)
1620
1621 printed 9007199254740992 if run directly from .py, but 9007199254740000
1622 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1623 str(float) instead of repr(float) when building code objects. marshal
1624 now uses repr(float) instead, which should reproduce floats to full
1625 machine precision (assuming the platform C float<->string I/O conversion
1626 functions are of good quality).
1627
1628 This may cause floating-point results to change in some cases, and
1629 usually for the better, but may also cause numerically unstable
1630 algorithms to break.
1631
Tim Peters2f228e72001-05-13 00:19:31 +00001632- The implementation of dicts suffers fewer collisions, which has speed
1633 benefits. However, the order in which dict entries appear in dict.keys(),
1634 dict.values() and dict.items() may differ from previous releases for a
1635 given dict. Nothing is defined about this order, so no program should
1636 rely on it. Nevertheless, it's easy to write test cases that rely on the
1637 order by accident, typically because of printing the str() or repr() of a
1638 dict to an "expected results" file. See Lib/test/test_support.py's new
1639 sortdict(dict) function for a simple way to display a dict in sorted
1640 order.
1641
Tim Peters7a3bfc32001-06-12 01:22:22 +00001642- Many other small changes to dicts were made, resulting in faster
1643 operation along the most common code paths.
1644
Guido van Rossum10315822001-05-01 20:54:30 +00001645- Dictionary objects now support the "in" operator: "x in dict" means
1646 the same as dict.has_key(x).
1647
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001648- The update() method of dictionaries now accepts generic mapping
1649 objects. Specifically the argument object must support the .keys()
1650 and __getitem__() methods. This allows you to say, for example,
1651 {}.update(UserDict())
1652
Guido van Rossum10315822001-05-01 20:54:30 +00001653- Iterators were added; this is a generalized way of providing values
1654 to a for loop. See PEP 234. There's a new built-in function iter()
1655 to return an iterator. There's a new protocol to get the next value
1656 from an iterator using the next() method (in Python) or the
1657 tp_iternext slot (in C). There's a new protocol to get iterators
1658 using the __iter__() method (in Python) or the tp_iter slot (in C).
1659 Iterating (i.e. a for loop) over a dictionary generates its keys.
1660 Iterating over a file generates its lines.
1661
Tim Petersf553f892001-05-01 20:45:31 +00001662- The following functions were generalized to work nicely with iterator
1663 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001664 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001665 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1666 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001667 join() method of strings
1668 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001669 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1670 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001671 right-hand side of assignment statements with multiple targets, such as
1672 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001673
Tim Petersd85e1022001-05-11 21:51:48 +00001674- Accessing module attributes is significantly faster (for example,
1675 random.random or os.path or yourPythonModule.yourAttribute).
1676
Tim Peterse63415e2001-05-08 04:38:29 +00001677- Comparing dictionary objects via == and != is faster, and now works even
1678 if the keys and values don't support comparisons other than ==.
1679
Tim Peters95bf9392001-05-10 08:32:44 +00001680- Comparing dictionaries in ways other than == and != is slower: there were
1681 insecurities in the dict comparison implementation that could cause Python
1682 to crash if the element comparison routines for the dict keys and/or
1683 values mutated the dicts. Making the code bulletproof slowed it down.
1684
Tim Peterseb28ef22001-06-02 05:27:19 +00001685- Collisions in dicts are resolved via a new approach, which can help
1686 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001687 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001688 faster now. Thanks to Christian Tismer for pointing out the cause and
1689 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001690
Tim Peters52e155e2001-06-16 05:42:57 +00001691- repr() is much faster for large containers (dict, list, tuple).
1692
1693
Tim Petersa814db52001-05-14 07:05:58 +00001694Library
1695
Fred Drake960fdf92001-07-20 18:38:26 +00001696- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1697 were added to the string module. These a locale-indenpendent
1698 constants, unlike letters, lowercase, and uppercase. These are now
1699 use in appropriate locations in the standard library.
1700
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001701- The flags used in dlopen calls can now be configured using
1702 sys.setdlopenflags and queried using sys.getdlopenflags.
1703
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001704- Fredrik Lundh's xmlrpclib is now a standard library module. This
1705 provides full client-side XML-RPC support. In addition,
1706 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1707 one asyncore-based). Thanks to Eric Raymond for the documentation.
1708
Guido van Rossum643d3912001-07-05 14:46:25 +00001709- The xrange() object is simplified: it no longer supports slicing,
1710 repetition, comparisons, efficient 'in' checking, the tolist()
1711 method, or the start, stop and step attributes. See PEP 260.
1712
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001713- A new function fnmatch.filter to filter lists of file names was added.
1714
Barry Warsawffd674d2001-05-22 16:00:10 +00001715- calendar.py uses month and day names based on the current locale.
1716
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001717- strop is now *really* obsolete (this was announced before with 1.6),
1718 and issues DeprecationWarning when used (except for the four items
1719 that are still imported into string.py).
1720
Tim Petersa814db52001-05-14 07:05:58 +00001721- Cookie.py now sorts key+value pairs by key in output strings.
1722
1723- pprint.isrecursive(object) didn't correctly identify recursive objects.
1724 Now it does.
1725
Tim Peters95b3f782001-05-14 18:39:41 +00001726- pprint functions now much faster for large containers (tuple, list, dict).
1727
Tim Peters7b9542a2001-06-10 23:40:19 +00001728- New 'q' and 'Q' format codes in the struct module, corresponding to C
1729 types "long long" and "unsigned long long" (on Windows, __int64). In
1730 native mode, these can be used only when the platform C compiler supports
1731 these types (when HAVE_LONG_LONG is #define'd by the Python config
1732 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001733 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1734 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001735
Guido van Rossum83213cc2001-06-12 16:48:52 +00001736- The site module installs a new built-in function 'help' that invokes
1737 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1738 it displays a message reminding the user to use 'help()' or
1739 'help(object)'.
1740
Tim Petersa814db52001-05-14 07:05:58 +00001741Tests
1742
1743- New test_mutants.py runs dict comparisons where the key and value
1744 comparison operators mutute the dicts randomly during comparison. This
1745 rapidly causes Python to crash under earlier releases (not for the faint
1746 of heart: it can also cause Win9x to freeze or reboot!).
1747
1748- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001749 pprint.isreadable() return sensible results. Also verifies that simple
1750 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001751
Tim Peters4324aa32001-05-28 22:30:08 +00001752C API
1753
1754- Removed the unused last_is_sticky argument from the internal
1755 _PyTuple_Resize(). If this affects you, you were cheating.
1756
1757
Guido van Rossum55a78992001-07-17 17:22:32 +00001758======================================================================
1759
1760
Guido van Rossumffe13be2001-04-16 18:46:45 +00001761What's New in Python 2.1 (final)?
1762=================================
1763
1764We only changed a few things since the last release candidate, all in
1765Python library code:
1766
1767- A bug in the locale module was fixed that affected locales which
1768 define no grouping for numeric formatting.
1769
1770- A few bugs in the weakref module's implementations of weak
1771 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1772 and the test suite was updated to check for these bugs.
1773
1774- An old bug in the os.path.walk() function (introduced in Python
1775 2.0!) was fixed: a non-existent file would cause an exception
1776 instead of being ignored.
1777
1778- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1779 PyChecker.
1780
1781
Guido van Rossum5b08f132001-04-16 02:05:23 +00001782What's New in Python 2.1c2?
1783===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001784
Guido van Rossum5b08f132001-04-16 02:05:23 +00001785A flurry of small changes, and one showstopper fixed in the nick of
1786time made it necessary to release another release candidate. The list
1787here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001788
Guido van Rossum5b08f132001-04-16 02:05:23 +00001789Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001790
Guido van Rossum5b08f132001-04-16 02:05:23 +00001791- Tim discovered a nasty bug in the dictionary code, caused by
1792 PyDict_Next() calling dict_resize(), and the GC code's use of
1793 PyDict_Next() violating an assumption in dict_items(). This was
1794 fixed with considerable amounts of band-aid, but the net effect is a
1795 saner and more robust implementation.
1796
1797- Made a bunch of symbols static that were accidentally global.
1798
1799Build and Ports
1800
1801- The setup.py script didn't check for a new enough version of zlib
1802 (1.1.3 is needed). Now it does.
1803
1804- Changed "make clean" target to also remove shared libraries.
1805
1806- Added a more general warning about the SGI Irix optimizer to README.
1807
1808Library
1809
1810- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1811 omitted the slash between host and file.html.
1812
1813- The mailbox module's _Mailbox class contained a completely broken
1814 and undocumented seek() method. Ripped it out.
1815
1816- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1817 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1818
1819- Fixed a few last-minute bugs in unittest.
1820
1821Extensions
1822
1823- Reverted the patch to the OpenSSL code in socketmodule.c to support
1824 RAND_status() and the EGD, and the subsequent patch that tried to
1825 fix it for pre-0.9.5 versions; the problem with the patch is that on
1826 some systems it issues a warning whenever socket is imported, and
1827 that's unacceptable.
1828
1829Tests
1830
1831- Fixed the pickle tests to work with "import test.test_pickle".
1832
1833- Tweaked test_locale.py to actually run the test Windows.
1834
1835- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1836 not "wb" (which is not a valid mode at all).
1837
1838- Fix pstats browser crashes. Import readline if it exists to make
1839 the user interface nicer.
1840
1841- Add "import thread" to the top of test modules that import the
1842 threading module (test_asynchat and test_threadedtempfile). This
1843 prevents test failures caused by a broken threading module resulting
1844 from a previously caught failed import.
1845
1846- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1847 needed on some platforms (e.g. Solaris 8) when the tests are run
1848 twice in succession.
1849
1850- Skip rather than fail test_sunaudiodev if no audio device is found.
1851
1852
1853What's New in Python 2.1c1?
1854===========================
1855
1856This list was significantly updated when 2.1c2 was released; the 2.1c1
1857release didn't mention most changes that were actually part of 2.1c1:
1858
1859Legal
1860
1861- Copyright was assigned to the Python Software Foundation (PSF) and a
1862 PSF license (very similar to the CNRI license) was added.
1863
1864- The CNRI copyright notice was updated to include 2001.
1865
1866Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001867
Guido van Rossumc9932722001-04-12 02:31:27 +00001868- After a public outcry, assignment to __debug__ is no longer illegal;
1869 instead, a warning is issued. It will become illegal in 2.2.
1870
Guido van Rossum5b08f132001-04-16 02:05:23 +00001871- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1872 "%#x" now always prepends "0x", even if the value is zero.
1873
1874- Fixed some nits in the bytecode compiler.
1875
1876- Fixed core dumps when calling certain kinds of non-functions.
1877
1878- Fixed various core dumps caused by reference count bugs.
1879
1880Build and Ports
1881
1882- Use INSTALL_SCRIPT to install script files.
1883
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001884- New port: SCO Unixware 7, by Billy G. Allie.
1885
Guido van Rossum5b08f132001-04-16 02:05:23 +00001886- Updated RISCOS port.
1887
1888- Updated BeOS port and notes.
1889
1890- Various other porting problems resolved.
1891
1892Library
1893
1894- The TERMIOS and SOCKET modules are now truly obsolete and
1895 unnecessary. Their symbols are incorporated in the termios and
1896 socket modules.
1897
1898- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1899 better tests for pickling.
1900
1901- threading: make Condition.wait() robust against KeyboardInterrupt.
1902
1903- zipfile: add support to zipfile to support opening an archive
1904 represented by an open file rather than a file name. Fix bug where
1905 the archive was not properly closed. Fixed a bug in this bugfix
1906 where flush() was called for a read-only file.
1907
1908- imputil: added an uninstall() method to the ImportManager.
1909
1910- Canvas: fixed bugs in lower() and tkraise() methods.
1911
1912- SocketServer: API change (added overridable close_request() method)
1913 so that the TCP server can explicitly close the request.
1914
1915- pstats: Eric Raymond added a simple interactive statistics browser,
1916 invoked when the module is run as a script.
1917
1918- locale: fixed a problem in format().
1919
1920- webbrowser: made it work when the BROWSER environment variable has a
1921 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1922 KDE 2. Fixed some other nits.
1923
1924- unittest: changes to allow using a different exception than
1925 AssertionError, and added a few more function aliases. Some other
1926 small changes.
1927
1928- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1929
1930- asynchat: fixed a critical bug in asynchat that slipped through the
1931 2.1b2 release. Fixed another rare bug.
1932
1933- Fix some unqualified except: clauses (always a bad code example).
1934
1935XML
1936
1937- pyexpat: new API get_version_string().
1938
1939- Fixed some minidom bugs.
1940
1941Extensions
1942
1943- Fixed a core dump in _weakref. Removed the weakref.mapping()
1944 function (it adds nothing to the API).
1945
1946- Rationalized the use of header files in the readline module, to make
1947 it compile (albeit with some warnings) with the very recent readline
1948 4.2, without breaking for earlier versions.
1949
1950- Hopefully fixed a buffering problem in linuxaudiodev.
1951
1952- Attempted a fix to make the OpenSSL support in the socket module
1953 work again with pre-0.9.5 versions of OpenSSL.
1954
1955Tests
1956
1957- Added a test case for asynchat and asyncore.
1958
1959- Removed coupling between tests where one test failing could break
1960 another.
1961
1962Tools
1963
1964- Ping added an interactive help browser to pydoc, fixed some nits
1965 in the rest of the pydoc code, and added some features to his
1966 inspect module.
1967
1968- An updated python-mode.el version 4.1 which integrates Ken
1969 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1970 much nicer in XEmacs and Emacs. When stepping through your program
1971 with pdb, in either the shell window or the *Python* window, the
1972 source file and line will be tracked by an arrow. Very cool!
1973
1974- IDLE: syntax warnings in interactive mode are changed into errors.
1975
1976- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001977 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001978
1979- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001980
Barry Warsaw11e89c72001-04-11 20:37:57 +00001981
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001982What's New in Python 2.1 beta 2?
1983================================
1984
Guido van Rossum053ae352001-03-22 14:17:21 +00001985(Unlisted are many fixed bugs, more documentation, etc.)
1986
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001987Core language, builtins, and interpreter
1988
Guido van Rossum053ae352001-03-22 14:17:21 +00001989- The nested scopes work (enabled by "from __future__ import
1990 nested_scopes") is completed; in particular, the future now extends
1991 into code executed through exec, eval() and execfile(), and into the
1992 interactive interpreter.
1993
1994- When calling a base class method (e.g. BaseClass.__init__(self)),
1995 this is now allowed even if self is not strictly spoken a class
1996 instance (e.g. when using metaclasses or the Don Beaudry hook).
1997
1998- Slice objects are now comparable but not hashable; this prevents
1999 dict[:] from being accepted but meaningless.
2000
2001- Complex division is now calculated using less braindead algorithms.
2002 This doesn't change semantics except it's more likely to give useful
2003 results in extreme cases. Complex repr() now uses full precision
2004 like float repr().
2005
2006- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2007
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002008- It is illegal to assign to the name __debug__, which is set when the
2009 interpreter starts. It is effectively a compile-time constant.
2010
2011- A warning will be issued if a global statement for a variable
2012 follows a use or assignment of that variable.
2013
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002014Standard library
2015
Guido van Rossum053ae352001-03-22 14:17:21 +00002016- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2017 inspired by JUnit), is now part of the standard library. You now
2018 have a choice of two testing frameworks: unittest requires you to
2019 write testcases as separate code, doctest gathers them from
2020 docstrings. Both approaches have their advantages and
2021 disadvantages.
2022
2023- A new module Tix was added, which wraps the Tix extension library
2024 for Tk. With that module, it is not necessary to statically link
2025 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2026 require" command. See Demo/tix/.
2027
2028- tzparse.py is now obsolete.
2029
2030- In gzip.py, the seek() and tell() methods are removed -- they were
2031 non-functional anyway, and it's better if callers can test for their
2032 existence with hasattr().
2033
2034Python/C API
2035
2036- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2037 that's already in the dictionary during a PyDict_Next() iteration.
2038 This used to fail occasionally when a dictionary resize operation
2039 could be triggered that would rehash all the keys. All other
2040 modifications to the dictionary are still off-limits during a
2041 PyDict_Next() iteration!
2042
2043- New extended APIs related to passing compiler variables around.
2044
2045- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2046 implement isinstance() and issubclass().
2047
2048- Py_BuildValue() now has a "D" conversion to create a Python complex
2049 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002050
Fred Drake4e262a92001-03-22 18:26:47 +00002051- Extensions types which support weak references must now set the
2052 field allocated for the weak reference machinery to NULL themselves;
2053 this is done to avoid the cost of checking each object for having a
2054 weakly referencable type in PyObject_INIT(), since most types are
2055 not weakly referencable.
2056
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002057- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2058 free variables and cell variables to and from the frame's f_locals.
2059
2060- Variants of several functions defined in pythonrun.h have been added
2061 to support the nested_scopes future statement. The variants all end
2062 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2063 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2064 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002065 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002066
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002067Distutils
2068
2069- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2070 into the release tree.
2071
Tim Peters0e57abf2001-05-02 07:39:38 +00002072- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002073 (an uninstaller, more customization of the installer's display)
2074
2075- from Jack Jansen: added Mac-specific code to generate a dialog for
2076 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002077 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002078 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002079
2080- added 'platforms' and 'keywords' to the set of metadata that can be
2081 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002082
2083- applied patches from Jason Tishler to make the compiler class work with
2084 Cygwin.
2085
2086
Tim Peters2fe289a2001-03-01 22:19:38 +00002087What's New in Python 2.1 beta 1?
2088================================
Tim Petersd66595f2001-02-04 03:09:53 +00002089
2090Core language, builtins, and interpreter
2091
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002092- Following an outcry from the community about the amount of code
2093 broken by the nested scopes feature introduced in 2.1a2, we decided
2094 to make this feature optional, and to wait until Python 2.2 (or at
2095 least 6 months) to make it standard. The option can be enabled on a
2096 per-module basis by adding "from __future__ import nested_scopes" at
2097 the beginning of a module (before any other statements, but after
2098 comments and an optional docstring). See PEP 236 (Back to the
2099 __future__) for a description of the __future__ statement. PEP 227
2100 (Statically Nested Scopes) has been updated to reflect this change,
2101 and to clarify the semantics in a number of endcases.
2102
2103- The nested scopes code, when enabled, has been hardened, and most
2104 bugs and memory leaks in it have been fixed.
2105
2106- Compile-time warnings are now generated for a number of conditions
2107 that will break or change in meaning when nested scopes are enabled:
2108
2109 - Using "from...import *" or "exec" without in-clause in a function
2110 scope that also defines a lambda or nested function with one or
2111 more free (non-local) variables. The presence of the import* or
2112 bare exec makes it impossible for the compiler to determine the
2113 exact set of local variables in the outer scope, which makes it
2114 impossible to determine the bindings for free variables in the
2115 inner scope. To avoid the warning about import *, change it into
2116 an import of explicitly name object, or move the import* statement
2117 to the global scope; to avoid the warning about bare exec, use
2118 exec...in... (a good idea anyway -- there's a possibility that
2119 bare exec will be deprecated in the future).
2120
2121 - Use of a global variable in a nested scope with the same name as a
2122 local variable in a surrounding scope. This will change in
2123 meaning with nested scopes: the name in the inner scope will
2124 reference the variable in the outer scope rather than the global
2125 of the same name. To avoid the warning, either rename the outer
2126 variable, or use a global statement in the inner function.
2127
Neil Schemenauera35c6882001-02-27 04:45:05 +00002128- An optional object allocator has been included. This allocator is
2129 optimized for Python objects and should be faster and use less memory
2130 than the standard system allocator. It is not enabled by default
2131 because of possible thread safety problems. The allocator is only
2132 protected by the Python interpreter lock and it is possible that some
2133 extension modules require a thread safe allocator. The object
2134 allocator can be enabled by providing the "--with-pymalloc" option to
2135 configure.
2136
Tim Petersd66595f2001-02-04 03:09:53 +00002137Standard library
2138
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002139- pyexpat now detects the expat version if expat.h defines it. A
2140 number of additional handlers are provided, which are only available
2141 since expat 1.95. In addition, the methods SetParamEntityParsing and
2142 GetInputContext of Parser objects are available with 1.95.x
2143 only. Parser objects now provide the ordered_attributes and
2144 specified_attributes attributes. A new module expat.model was added,
2145 which offers a number of additional constants if 1.95.x is used.
2146
2147- xml.dom offers the new functions registerDOMImplementation and
2148 getDOMImplementation.
2149
2150- xml.dom.minidom offers a toprettyxml method. A number of DOM
2151 conformance issues have been resolved. In particular, Element now
2152 has an hasAttributes method, and the handling of namespaces was
2153 improved.
2154
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002155- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2156 getting information about live Python code, and pydoc.py, a module
2157 for interactively converting docstrings to HTML or text.
2158 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002159 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002160 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2161 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002162
Tim Peters1eff7962001-03-01 02:31:33 +00002163- New library module difflib.py, primarily packaging the SequenceMatcher
2164 class at the heart of the popular ndiff.py file-comparison tool.
2165
2166- doctest.py (a framework for verifying Python code examples in docstrings)
2167 is now part of the std library.
2168
Tim Petersd66595f2001-02-04 03:09:53 +00002169Windows changes
2170
Guido van Rossume3955a82001-03-02 14:05:59 +00002171- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2172 small GUI that lets you browse the module docstrings using your
2173 default web browser.
2174
Tim Peters1eff7962001-03-01 02:31:33 +00002175- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2176 Platforms) is implemented. See
2177
2178 http://python.sourceforge.net/peps/pep-0235.html
2179
2180 for full details, especially the "Current Lower-Left Semantics" section.
2181 The new Windows import rules are simpler than before:
2182
2183 A. If the PYTHONCASEOK environment variable exists, same as
2184 before: silently accept the first case-insensitive match of any
2185 kind; raise ImportError if none found.
2186
2187 B. Else search sys.path for the first case-sensitive match; raise
2188 ImportError if none found.
2189
2190 The same rules have been implented on other platforms with case-
2191 insensitive but case-preserving filesystems too (including Cygwin, and
2192 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002193
Tim Peters25a9ce32001-02-19 07:06:36 +00002194- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2195 what it's supposed to do (and does do under NT and 2000) via direct
2196 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002197 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002198 all Win9x systems before.
2199
Tim Peters1eff7962001-03-01 02:31:33 +00002200- Build: Subproject _test (effectively) renamed to _testcapi.
2201
Tim Peters2fe289a2001-03-01 22:19:38 +00002202New platforms
2203
2204- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2205 Thanks to Steven Majewski!
2206
2207- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2208 Tishler!
2209
Guido van Rossum9089b272001-03-02 06:49:50 +00002210- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2211 Schwertberger! See RISCOS/README for more information -- it seems
2212 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002213 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002214
Tim Peters25a9ce32001-02-19 07:06:36 +00002215
Tim Petersd7b5e882001-01-25 03:36:26 +00002216What's New in Python 2.1 alpha 2?
2217=================================
Tim Peters40ead762001-01-27 05:35:26 +00002218
Tim Petersd7b5e882001-01-25 03:36:26 +00002219Core language, builtins, and interpreter
2220
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002221- Scopes nest. If a name is used in a function or class, but is not
2222 local, the definition in the nearest enclosing function scope will
2223 be used. One consequence of this change is that lambda statements
2224 could reference variables in the namespaces where the lambda is
2225 defined. In some unusual cases, this change will break code.
2226
2227 In all previous version of Python, names were resolved in exactly
2228 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002229 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002230 function A is defined within a function B, the names bound in B are
2231 not visible in A. The new rules make names bound in B visible in A,
2232 unless A contains a name binding that hides the binding in B.
2233
2234 Section 4.1 of the reference manual describes the new scoping rules
2235 in detail. The test script in Lib/test/test_scope.py demonstrates
2236 some of the effects of the change.
2237
2238 The new rules will cause existing code to break if it defines nested
2239 functions where an outer function has local variables with the same
2240 name as globals or builtins used by the inner function. Example:
2241
2242 def munge(str):
2243 def helper(x):
2244 return str(x)
2245 if type(str) != type(''):
2246 str = helper(str)
2247 return str.strip()
2248
2249 Under the old rules, the name str in helper() is bound to the
2250 builtin function str(). Under the new rules, it will be bound to
2251 the argument named str and an error will occur when helper() is
2252 called.
2253
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002254- The compiler will report a SyntaxError if "from ... import *" occurs
2255 in a function or class scope. The language reference has documented
2256 that this case is illegal, but the compiler never checked for it.
2257 The recent introduction of nested scope makes the meaning of this
2258 form of name binding ambiguous. In a future release, the compiler
2259 may allow this form when there is no possibility of ambiguity.
2260
Tim Peters40ead762001-01-27 05:35:26 +00002261- repr(string) is easier to read, now using hex escapes instead of octal,
2262 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2263
2264 >>> "\texample \r\n" + chr(0) + chr(255)
2265 '\texample \r\n\x00\xff' # in 2.1
2266 '\011example \015\012\000\377' # in 2.0
2267
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002268- Functions are now compared and hashed by identity, not by value, since
2269 the func_code attribute is writable.
2270
Fred Drakefb9d7122001-02-01 20:00:40 +00002271- Weak references (PEP 205) have been added. This involves a few
2272 changes in the core, an extension module (_weakref), and a Python
2273 module (weakref). The weakref module is the public interface. It
2274 includes support for "explicit" weak references, proxy objects, and
2275 mappings with weakly held values.
2276
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002277- A 'continue' statement can now appear in a try block within the body
2278 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002279 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002280
Tim Petersd7b5e882001-01-25 03:36:26 +00002281Standard library
2282
Barry Warsaw30dbd142001-01-31 22:14:01 +00002283- mailbox.py now has a new class, PortableUnixMailbox which is
2284 identical to UnixMailbox but uses a more portable scheme for
2285 determining From_ separators. Also, the constructors for all the
2286 classes in this module have a new optional `factory' argument, which
2287 is a callable used when new message classes must be instantiated by
2288 the next() method.
2289
Tim Petersd7b5e882001-01-25 03:36:26 +00002290- random.py is now self-contained, and offers all the functionality of
2291 the now-deprecated whrandom.py. See the docs for details. random.py
2292 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002293 and restoring the internal state of the generator; and jumpahead(n),
2294 for quickly forcing the internal state to be the same as if n calls to
2295 random() had been made. The latter is particularly useful for multi-
2296 threaded programs, creating one instance of the random.Random() class for
2297 each thread, then using .jumpahead() to force each instance to use a
2298 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002299
Tim Peters0de88fc2001-02-01 04:59:18 +00002300- random.py's seed() function is new. For bit-for-bit compatibility with
2301 prior releases, use the whseed function instead. The new seed function
2302 addresses two problems: (1) The old function couldn't produce more than
2303 about 2**24 distinct internal states; the new one about 2**45 (the best
2304 that can be done in the Wichmann-Hill generator). (2) The old function
2305 sometimes produced identical internal states when passed distinct
2306 integers, and there was no simple way to predict when that would happen;
2307 the new one guarantees to produce distinct internal states for all
2308 arguments in [0, 27814431486576L).
2309
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002310- The socket module now supports raw packets on Linux. The socket
2311 family is AF_PACKET.
2312
Tim Peters9ea17ac2001-02-02 05:57:15 +00002313- test_capi.py is a start at running tests of the Python C API. The tests
2314 are implemented by the new Modules/_testmodule.c.
2315
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002316- A new extension module, _symtable, provides provisional access to the
2317 internal symbol table used by the Python compiler. A higher-level
2318 interface will be added on top of _symtable in a future release.
2319
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002320- Removed the obsolete soundex module.
2321
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002322- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2323 the isSameNode method; NamedNodeMap the get method.
2324
2325- xml.sax.expatreader supports the lexical handler property; it
2326 generates comment, startCDATA, and endCDATA events.
2327
Tim Petersee826f82001-01-31 19:39:44 +00002328Windows changes
2329
2330- Build procedure: the zlib project is built in a different way that
2331 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002332 the zlib binary used. See PCbuild\readme.txt for details. Your old
2333 zlib-related directories can be deleted; you'll need to download fresh
2334 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002335
Tim Peters9ea17ac2001-02-02 05:57:15 +00002336- Build: New subproject _test for the benefit of test_capi.py (see above).
2337
Tim Petersb16c56f2001-02-02 21:24:51 +00002338- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2339 interface to some Python compiler internals).
2340
2341- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002342 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002343
Tim Petersa3a3a032000-11-30 05:22:44 +00002344What's New in Python 2.1 alpha 1?
2345=================================
2346
2347Core language, builtins, and interpreter
2348
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002349- There is a new Unicode companion to the PyObject_Str() API
2350 called PyObject_Unicode(). It behaves in the same way as the
2351 former, but assures that the returned value is an Unicode object
2352 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002353
Guido van Rossumf98eda02001-01-17 15:54:45 +00002354- The comparison operators support "rich comparison overloading" (PEP
2355 207). C extension types can provide a rich comparison function in
2356 the new tp_richcompare slot in the type object. The cmp() function
2357 and the C function PyObject_Compare() first try the new rich
2358 comparison operators before trying the old 3-way comparison. There
2359 is also a new C API PyObject_RichCompare() (which also falls back on
2360 the old 3-way comparison, but does not constrain the outcome of the
2361 rich comparison to a Boolean result).
2362
2363 The rich comparison function takes two objects (at least one of
2364 which is guaranteed to have the type that provided the function) and
2365 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2366 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2367 object, which may be NotImplemented (in which case the tp_compare
2368 slot function is used as a fallback, if defined).
2369
2370 Classes can overload individual comparison operators by defining one
2371 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002372 __ge__. There are no explicit "reflected argument" versions of
2373 these; instead, __lt__ and __gt__ are each other's reflection,
2374 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2375 reflection (similar at the C level). No other implications are
2376 made; in particular, Python does not assume that == is the Boolean
2377 inverse of !=, or that < is the Boolean inverse of >=. This makes
2378 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002379
2380 Classes or types that want to implement (in)equality tests but not
2381 the ordering operators (i.e. unordered types) should implement ==
2382 and !=, and raise an error for the ordering operators.
2383
Guido van Rossuma88479f2001-01-18 14:28:08 +00002384 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002385 Boolean; e.g. a matrix type might want to return a matrix of bits
2386 for A < B, giving elementwise comparisons. Such types should ensure
2387 that any interpretation of their value in a Boolean context raises
2388 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2389 at the C level) to always raise an exception.
2390
Guido van Rossuma88479f2001-01-18 14:28:08 +00002391- Complex numbers use rich comparisons to define == and != but raise
2392 an exception for <, <=, > and >=. Unfortunately, this also means
2393 that cmp() of two complex numbers raises an exception when the two
2394 numbers differ. Since it is not mathematically meaningful to compare
2395 complex numbers except for equality, I hope that this doesn't break
2396 too much code.
2397
Tim Peters3389f192001-02-18 08:48:49 +00002398- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002399 not defined by the language, other than that it's arbitrary but
2400 consistent (see the Reference Manual). An implementation detail changed
2401 in 2.1a1 such that None now compares less than any other object. Code
2402 relying on this new behavior (like code that relied on the previous
2403 behavior) does so at its own risk.
2404
Barry Warsaw573b5412001-01-15 20:43:18 +00002405- Functions and methods now support getting and setting arbitrarily
2406 named attributes (PEP 232). Functions have a new __dict__
2407 (a.k.a. func_dict) which hold the function attributes. Methods get
2408 and set attributes on their underlying im_func. It is a TypeError
2409 to set an attribute on a bound method.
2410
Guido van Rossum051e3352001-01-15 19:11:10 +00002411- The xrange() object implementation has been improved so that
2412 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2413 limitation that in this case len(xrange(sys.maxint)) can't be
2414 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2415 work fine as long as the index i doesn't actually reach 2**31.
2416 (Python uses regular ints for sequence and string indices; fixing
2417 that is much more work.)
2418
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002419- Two changes to from...import:
2420
Guido van Rossumba381232001-02-03 15:06:40 +00002421 1) "from M import X" now works even if (after loading module M)
2422 sys.modules['M'] is not a real module; it's basically a getattr()
2423 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002424
2425 2) "from M import *" now looks for M.__all__ to decide which names to
2426 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2427 filters out names starting with '_' as before. Whether or not
2428 __all__ exists, there's no restriction on the type of M.
2429
Guido van Rossumf61f1662001-01-10 20:13:55 +00002430- File objects have a new method, xreadlines(). This is the fastest
2431 way to iterate over all lines in a file:
2432
2433 for line in file.xreadlines():
2434 ...do something to line...
2435
2436 See the xreadlines module (mentioned below) for how to do this for
2437 other file-like objects.
2438
2439- Even if you don't use file.xreadlines(), you may expect a speedup on
2440 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002441 quite a bit in platform-specific ways: on systems (like Linux) that
2442 support flockfile(), getc_unlocked(), and funlockfile(), those are
2443 used by default. On systems (like Windows) without getc_unlocked(),
2444 a complicated (but still thread-safe) method using fgets() is used by
2445 default.
2446
Tim Petersd52269b2001-01-25 06:23:18 +00002447 You can force use of the fgets() method by #define'ing
2448 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002449 getc_unlocked()).
2450
Tim Petersd52269b2001-01-25 06:23:18 +00002451 You can force fgets() not to be used by #define'ing
2452 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002453 test_bufio.py fails -- and let us know if it does!).
2454
2455- In addition, the fileinput module, while still slower than the other
2456 methods on most platforms, has been sped up too, by using
2457 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002458
2459- Support for run-time warnings has been added, including a new
2460 command line option (-W) to specify the disposition of warnings.
2461 See the description of the warnings module below.
2462
2463- Extensive changes have been made to the coercion code. This mostly
2464 affects extension modules (which can now implement mixed-type
2465 numerical operators without having to use coercion), but
2466 occasionally, in boundary cases the coercion semantics have changed
2467 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002468 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002469 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002470 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002471
Guido van Rossumf98eda02001-01-17 15:54:45 +00002472- In connection with the coercion changes, a new built-in singleton
2473 object, NotImplemented is defined. This can be returned for
2474 operations that wish to indicate they are not implemented for a
2475 particular combination of arguments. From C, this is
2476 Py_NotImplemented.
2477
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002478- The interpreter accepts now bytecode files on the command line even
2479 if they do not have a .pyc or .pyo extension. On Linux, after executing
2480
Martin v. Löwise214baa2001-02-04 22:37:56 +00002481import imp,sys,string
2482magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2483reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2484open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002485
2486 any byte code file can be used as an executable (i.e. as an argument
2487 to execve(2)).
2488
Tim Peters9940b802000-12-01 07:59:35 +00002489- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002490 character. In 1.6 and earlier, they never produced a sign,
2491 and raised an error if the value of the long was too large
2492 to fit in a Python int. In 2.0, they produced a sign if and
2493 only if too large to fit in an int. This was inconsistent
2494 across platforms (because the size of an int varies across
2495 platforms), and inconsistent with hex() and oct(). Example:
2496
2497 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002498 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002499 'ffffffbe' # in 2.0 and before, on 32-bit machines
2500 >>> hex(-0x42L)
2501 '-0x42L' # in all versions of Python
2502
Tim Peters9940b802000-12-01 07:59:35 +00002503 The behavior of %d formats for negative Python longs remains
2504 the same as in 2.0 (although in 1.6 and before, they raised
2505 an error if the long didn't fit in a Python int).
2506
2507 %u formats don't make sense for Python longs, but are allowed
2508 and treated the same as %d in 2.1. In 2.0, a negative long
2509 formatted via %u produced a sign if and only if too large to
2510 fit in an int. In 1.6 and earlier, a negative long formatted
2511 via %u raised an error if it was too big to fit in an int.
2512
Guido van Rossum3661d392000-12-12 22:10:31 +00002513- Dictionary objects have an odd new method, popitem(). This removes
2514 an arbitrary item from the dictionary and returns it (in the form of
2515 a (key, value) pair). This can be useful for algorithms that use a
2516 dictionary as a bag of "to do" items and repeatedly need to pick one
2517 item. Such algorithms normally end up running in quadratic time;
2518 using popitem() they can usually be made to run in linear time.
2519
Tim Peters36cdad12000-12-29 02:06:45 +00002520Standard library
2521
Thomas Woutersfe385252001-01-19 23:16:56 +00002522- In the time module, the time argument to the functions strftime,
2523 localtime, gmtime, asctime and ctime is now optional, defaulting to
2524 the current time (in the local timezone).
2525
Guido van Rossumda91f222001-01-15 16:36:08 +00002526- The ftplib module now defaults to passive mode, which is deemed a
2527 more useful default given that clients are often inside firewalls
2528 these days. Note that this could break if ftplib is used to connect
2529 to a *server* that is inside a firewall, from outside; this is
2530 expected to be a very rare situation. To fix that, you can call
2531 ftp.set_pasv(0).
2532
Martin v. Löwis10a27872001-01-13 09:54:41 +00002533- The module site now treats .pth files not only for path configuration,
2534 but also supports extensions to the initialization code: Lines starting
2535 with import are executed.
2536
Guido van Rossumf61f1662001-01-10 20:13:55 +00002537- There's a new module, warnings, which implements a mechanism for
2538 issuing and filtering warnings. There are some new built-in
2539 exceptions that serve as warning categories, and a new command line
2540 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2541 turns warnings into errors). warnings.warn(message[, category])
2542 issues a warning message; this can also be called from C as
2543 PyErr_Warn(category, message).
2544
2545- A new module xreadlines was added. This exports a single factory
2546 function, xreadlines(). The intention is that this code is the
2547 absolutely fastest way to iterate over all lines in an open
2548 file(-like) object:
2549
2550 import xreadlines
2551 for line in xreadlines.xreadlines(file):
2552 ...do something to line...
2553
2554 This is equivalent to the previous the speed record holder using
2555 file.readlines(sizehint). Note that if file is a real file object
2556 (as opposed to a file-like object), this is equivalent:
2557
2558 for line in file.xreadlines():
2559 ...do something to line...
2560
Tim Peters36cdad12000-12-29 02:06:45 +00002561- The bisect module has new functions bisect_left, insort_left,
2562 bisect_right and insort_right. The old names bisect and insort
2563 are now aliases for bisect_right and insort_right. XXX_right
2564 and XXX_left methods differ in what happens when the new element
2565 compares equal to one or more elements already in the list: the
2566 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002567 right. Code that doesn't care where equal elements end up should
2568 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002569
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002570- The new curses.panel module wraps the panel library that forms part
2571 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2572
Guido van Rossumf61f1662001-01-10 20:13:55 +00002573- The SocketServer module now sets the allow_reuse_address flag by
2574 default in the TCPServer class.
2575
2576- A new function, sys._getframe(), returns the stack frame pointer of
2577 the caller. This is intended only as a building block for
2578 higher-level mechanisms such as string interpolation.
2579
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002580- The pyexpat module supports a number of new handlers, which are
2581 available only in expat 1.2. If invocation of a callback fails, it
2582 will report an additional frame in the traceback. Parser objects
2583 participate now in garbage collection. If expat reports an unknown
2584 encoding, pyexpat will try to use a Python codec; that works only
2585 for single-byte charsets. The parser type objects is exposed as
2586 XMLParserObject.
2587
2588- xml.dom now offers standard definitions for symbolic node type and
2589 exception code constants, and a hierarchy of DOM exceptions. minidom
2590 was adjusted to use them.
2591
2592- The conformance of xml.dom.minidom to the DOM specification was
2593 improved. It detects a number of additional error cases; the
2594 previous/next relationship works even when the tree is modified;
2595 Node supports the normalize() method; NamedNodeMap, DocumentType and
2596 DOMImplementation classes were added; Element supports the
2597 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2598 method.
2599
Guido van Rossumf61f1662001-01-10 20:13:55 +00002600Build issues
2601
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002602- For Unix (and Unix-compatible) builds, configuration and building of
2603 extension modules is now greatly automated. Rather than having to
2604 edit the Modules/Setup file to indicate which modules should be
2605 built and where their include files and libraries are, a
2606 distutils-based setup.py script now takes care of building most
2607 extension modules. All extension modules built this way are built
2608 as shared libraries. Only a few modules that must be linked
2609 statically are still listed in the Setup file; you won't need to
2610 edit their configuration.
2611
2612- Python should now build out of the box on Cygwin. If it doesn't,
2613 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002614
2615- Python now always uses its own (renamed) implementation of getopt()
2616 -- there's too much variation among C library getopt()
2617 implementations.
2618
2619- C++ compilers are better supported; the CXX macro is always set to a
2620 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002621
Tim Petersd92dfe02000-12-12 01:18:41 +00002622Windows changes
2623
2624- select module: By default under Windows, a select() call
2625 can specify no more than 64 sockets. Python now boosts
2626 this Microsoft default to 512. If you need even more than
2627 that, see the MS docs (you'll need to #define FD_SETSIZE
2628 and recompile Python from source).
2629
Guido van Rossumf61f1662001-01-10 20:13:55 +00002630- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2631 subdirectory is no more!
2632
Tim Petersa3a3a032000-11-30 05:22:44 +00002633
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002634What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002635=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002636
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002637Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002638changes are in the file HISTORY. If you are making the jump directly
2639from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2640HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002641
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002642Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2643the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2644http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002645
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002646--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002647
2648======================================================================
2649
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002650What's new in 2.0 (since release candidate 1)?
2651==============================================
2652
2653Standard library
2654
2655- The copy_reg module was modified to clarify its intended use: to
2656 register pickle support for extension types, not for classes.
2657 pickle() will raise a TypeError if it is passed a class.
2658
2659- Fixed a bug in gettext's "normalize and expand" code that prevented
2660 it from finding an existing .mo file.
2661
2662- Restored support for HTTP/0.9 servers in httplib.
2663
Tim Peters989b7b92000-10-16 20:24:53 +00002664- The math module was changed to stop raising OverflowError in case of
2665 underflow, and return 0 instead in underflow cases. Whether Python
2666 used to raise OverflowError in case of underflow was platform-
2667 dependent (it did when the platform math library set errno to ERANGE
2668 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002669
2670- Fixed a bug in StringIO that occurred when the file position was not
2671 at the end of the file and write() was called with enough data to
2672 extend past the end of the file.
2673
2674- Fixed a bug that caused Tkinter error messages to get lost on
2675 Windows. The bug was fixed by replacing direct use of
2676 interp->result with Tcl_GetStringResult(interp).
2677
2678- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2679 redirect response.
2680
2681- Several changes were made to distutils: Some debugging code was
2682 removed from util. Fixed the installer used when an external zip
2683 program (like WinZip) is not found; the source code for this
2684 installer is in Misc/distutils. check_lib() was modified to behave
2685 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2686 test for whether installed modules are on sys.path was changed to
2687 use both normcase() and normpath().
2688
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002689- Several minor bugs were fixed in the xml package (the minidom,
2690 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002691
2692- The regression test driver (regrtest.py) behavior when invoked with
2693 -l changed: It now reports a count of objects that are recognized as
2694 garbage but not freed by the garbage collector.
2695
Tim Peters989b7b92000-10-16 20:24:53 +00002696- The regression test for the math module was changed to test
2697 exceptional behavior when the test is run in verbose mode. Python
2698 cannot yet guarantee consistent exception behavior across platforms,
2699 so the exception part of test_math is run only in verbose mode, and
2700 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002701
2702Internals
2703
2704- PyOS_CheckStack() has been disabled on Win64, where it caused
2705 test_sre to fail.
2706
2707Build issues
2708
2709- Changed compiler flags, so that gcc is always invoked with -Wall and
2710 -Wstrict-prototypes. Users compiling Python with GCC should see
2711 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002712 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002713 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002714
Tim Petersa3a3a032000-11-30 05:22:44 +00002715- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002716
2717Tools and other miscellany
2718
2719- The compiler in Tools/compiler was updated to support the new
2720 language features introduced in 2.0: extended print statement, list
2721 comprehensions, and augmented assignments. The new compiler should
2722 also be backwards compatible with Python 1.5.2; the compiler will
2723 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002724 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002725
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002726What's new in 2.0 release candidate 1 (since beta 2)?
2727=====================================================
2728
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002729What is release candidate 1?
2730
2731We believe that release candidate 1 will fix all known bugs that we
2732intend to fix for the 2.0 final release. This release should be a bit
2733more stable than the previous betas. We would like to see even more
2734widespread testing before the final release, so we are producing this
2735release candidate. The final release will be exactly the same unless
2736any show-stopping (or brown bag) bugs are found by testers of the
2737release candidate.
2738
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002739All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002740to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002741
2742Core language, builtins, and interpreter
2743
2744- A bug that caused crashes when __coerce__ was used with augmented
2745 assignment, e.g. +=, was fixed.
2746
2747- Raise ZeroDivisionError when raising zero to a negative number,
2748 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2749 power operator and the result of math.pow(0.0, -2.0) will vary by
2750 platform. On Linux, it raises a ValueError.
2751
2752- A bug in Unicode string interpolation was fixed that occasionally
2753 caused errors with formats including "%%". For example, the
2754 following expression "%% %s" % u"abc" no longer raises a TypeError.
2755
2756- Compilation of deeply nested expressions raises MemoryError instead
2757 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2758
2759- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2760 rendering them useless. They are now written in binary mode again.
2761
2762Standard library
2763
2764- Keyword arguments are now accepted for most pattern and match object
2765 methods in SRE, the standard regular expression engine.
2766
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002767- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002768 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002769
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002770- Several bugs in the Unicode handling and error handling in _tkinter
2771 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002772
2773- Fix memory management errors in Merge() and Tkapp_Call() routines.
2774
2775- Several changes were made to cStringIO to make it compatible with
2776 the file-like object interface and with StringIO. If operations are
2777 performed on a closed object, an exception is raised. The truncate
2778 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002779 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002780
2781- There were many changes made to the linuxaudiodev module and its
2782 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002783 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002784
2785 Note that this module is named poorly, because it should work
2786 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002787 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002788
2789 The module now raises exceptions when errors occur instead of
2790 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2791 audio) and defines a getptr() method that calls the
2792 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2793
2794- The library_version attribute, introduced in an earlier beta, was
2795 removed because it can not be supported with early versions of the C
2796 readline library, which provides no way to determine the version at
2797 compile-time.
2798
2799- The binascii module is now enabled on Win64.
2800
Tim Peters46446d62000-10-09 21:19:31 +00002801- tokenize.py no longer suffers "recursion depth" errors when parsing
2802 programs with very long string literals.
2803
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002804Internals
2805
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002806- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002807 which is called when the interpreter starts up to determine where
2808 the standard library is installed. These vulnerabilities affect all
2809 previous versions of Python and can be exploited by setting very
2810 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2811 setuid Python script, although use of the wrapper in
2812 Misc/setuid-prog.c will eliminate the vulnerability.
2813
2814- Fixed garbage collection bugs in instance creation that were
2815 triggered when errors occurred during initialization. The solution,
2816 applied in cPickle and in PyInstance_New(), is to call
2817 PyObject_GC_Init() after the initialization of the object's
2818 container attributes is complete.
2819
2820- pyexpat adds definitions of PyModule_AddStringConstant and
2821 PyModule_AddObject if the Python version is less than 2.0, which
2822 provides compatibility with PyXML on Python 1.5.2.
2823
2824- If the platform has a bogus definition for LONG_BIT (the number of
2825 bits in a long), an error will be reported at compile time.
2826
2827- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2828 collection crashes and possibly other, unreported crashes.
2829
2830- Fixed a memory leak in _PyUnicode_Fini().
2831
2832Build issues
2833
2834- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002835 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002836 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002837
2838- The mmap.PAGESIZE constant is now initialized using sysconf when
2839 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2840
2841- The md5 file should now compile on all platforms.
2842
2843- The select module now compiles on platforms that do not define
2844 POLLRDNORM and related constants.
2845
2846- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002847 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002848
Jeremy Hylton10921202000-10-09 18:34:12 +00002849- BeOS: A number of changes were made to the build and installation
2850 process. ar-fake now operates on a directory of object files.
2851 dl_export.h is gone, and its macros now appear on the mwcc command
2852 line during build on PPC BeOS.
2853
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002854- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002855 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002856
2857- Cygwin: Support for shared libraries, Tkinter, and sockets.
2858
2859- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2860
2861Tools and other miscellany
2862
2863- Removed debugging prints from main used with freeze.
2864
Tim Peters46446d62000-10-09 21:19:31 +00002865- IDLE auto-indent no longer crashes when it encounters Unicode
2866 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002867
2868What's new in 2.0 beta 2 (since beta 1)?
2869========================================
2870
2871Core language, builtins, and interpreter
2872
Tim Peters482c0212000-09-26 06:33:09 +00002873- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002874 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002875
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002876- Add -h and -V command line options to print the usage message and
2877 Python version number and exit immediately.
2878
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002879- eval() and exec accept Unicode objects as code parameters.
2880
2881- getattr() and setattr() now also accept Unicode objects for the
2882 attribute name, which are converted to strings using the default
2883 encoding before lookup.
2884
2885- Multiplication on string and Unicode now does proper bounds
2886 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2887 string is too long."
2888
2889- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002890 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002891
Jeremy Hylton1b618592000-09-26 05:32:36 +00002892
2893Standard library and extensions
2894
Guido van Rossum5b08f132001-04-16 02:05:23 +00002895- socket module: the OpenSSL code now adds support for RAND_status()
2896 and EGD (Entropy Gathering Device).
2897
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002898- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002899 argument checking; it still takes no arguments.
2900
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002901- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002902
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002903- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002904
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002905- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002906
2907- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002908 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002909
2910- copy: Copy Unicode objects atomically.
2911
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002912- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002913
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002914- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002915
Fred Drake67233bc2000-09-26 16:40:27 +00002916- dbm: Add get() and setdefault() methods to dbm object. Add constant
2917 `library' to module that names the library used. Added doc strings
2918 and method names to error messages. Uses configure to determine
2919 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2920 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002921
2922- distutils: Update to version 0.9.3.
2923
2924- dl: Add several dl.RTLD_ constants.
2925
2926- fpectl: Now supported on FreeBSD.
2927
2928- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2929 found by the collector will be saved in gc.garbage. This is useful
2930 for debugging a program that creates reference cycles.
2931
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002932- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002933 of HTTP class. Do not close socket on zero-length response. Do not
2934 crash when server sends invalid content-length header.
2935
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002936- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002937
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002938- marshal: When reading a short, sign-extend on platforms where shorts
2939 are bigger than 16 bits. When reading a long, repair the unportable
2940 sign extension that was being done for 64-bit machines. (It assumed
2941 that signed right shift sign-extends.)
2942
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002943- operator: Add contains(), invert(), __invert__() as aliases for
2944 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002945
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002946- os: Add support for popen2() and popen3() on all platforms where
2947 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002948
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002949- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002950 clicking on a file in Explorer (or passing the file name to the
2951 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002952
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002953- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002954 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002955
2956- pickle: Now raises ValueError when an invalid pickle that contains
2957 a non-string repr where a string repr was expected. This behavior
2958 matches cPickle.
2959
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002960- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002961
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002962- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002963
2964- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002965 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002966 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002967
2968- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002969 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002970
2971- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002972 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002973 few cycles during startup since the first call to
2974 setdefaultencoding() will initialize the codec registry and the
2975 encodings package.
2976
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002977- socket: Support for size hint in readlines() method of object returned
2978 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002979
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002980- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002981 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002982 is followed by whitespace.
2983
Tim Petersa3a3a032000-11-30 05:22:44 +00002984- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002985
2986- struct: Check ranges for bytes and shorts.
2987
2988- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002989 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002990
2991- Tkinter: Image objects are now guaranteed to have unique ids. Set
2992 event.delta to zero if Tk version doesn't support mousewheel.
2993 Removed some debugging prints.
2994
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002995- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002996
Fred Drake67233bc2000-09-26 16:40:27 +00002997- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002998 which works around a bug in Norton AntiVirus 2000 that leads directly
2999 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003000
3001- xml: New version detection code allows PyXML to override standard
3002 XML package if PyXML version is greater than 0.6.1.
3003
Fred Drake64bb3802000-09-26 16:21:35 +00003004- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3005 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3006 tree only for nodes which are sufficiently interesting to a specific
3007 application. Does not provide the HTML-specific extensions. Still
3008 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003009
Fred Drake64bb3802000-09-26 16:21:35 +00003010- xml.sax: SAX 2 support for Python, including all the handler
3011 interfaces needed to process XML 1.0 compliant XML. Some
3012 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003013
Fred Drake64bb3802000-09-26 16:21:35 +00003014- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3015 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003016
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003017
Jeremy Hylton1b618592000-09-26 05:32:36 +00003018C API
3019
3020- Add three new convenience functions for module initialization --
3021 PyModule_AddObject(), PyModule_AddIntConstant(), and
3022 PyModule_AddStringConstant().
3023
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003024- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003025 removed and add #error to Python.h if NULL isn't defined after
3026 #include of stdio.h.
3027
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003028- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003029 backwards compatibility (at the source level) with old extensions.
3030
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003031- A wrapper API was added for signal() and sigaction(). Instead of
3032 either function, always use PyOS_getsig() to get a signal handler
3033 and PyOS_setsig() to set one. A new convenience typedef
3034 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003035
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003036- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003037 internal data buffer and size of a string object -- or the default
3038 encoded version of a Unicode object.
3039
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003040- PyString_Size() and PyString_AsString() accept Unicode objects.
3041
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003042- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003043 exists). INT_MAX and LONG_MAX will always be defined, even if
3044 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003045
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003046- PyFloat_FromString takes a second argument, pend, that was
3047 effectively useless. It is now officially useless but preserved for
3048 backwards compatibility. If the pend argument is not NULL, *pend is
3049 set to NULL.
3050
3051- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3052 for the attribute name. See note on getattr() above.
3053
3054- A few bug fixes to argument processing for Unicode.
3055 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3056 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3057 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003058 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003059
3060- Py_BuildValue accepts B format (for bgen-generated code).
3061
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003062
Jeremy Hylton1b618592000-09-26 05:32:36 +00003063Internals
3064
3065- On Unix, fix code for finding Python installation directory so that
3066 it works when argv[0] is a relative path.
3067
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003068- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003069 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003070 rather than by generating a copy of the object.
3071
Tim Peters482c0212000-09-26 06:33:09 +00003072- Several of the internal Unicode tables are much smaller now, and
3073 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003074
Jeremy Hylton97693b02000-09-26 17:42:51 +00003075- In the garbage collector: Fixed bug in collection of tuples. Fixed
3076 bug that caused some instances to be removed from the container set
3077 while they were still live. Fixed parsing in gc.set_debug() for
3078 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003079
3080- Fixed refcount problem in instance deallocation that only occurred
3081 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3082
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003083- On Windows, getpythonregpath is now protected against null data in
3084 registry key.
3085
3086- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003087 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003088
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003089
Jeremy Hylton1b618592000-09-26 05:32:36 +00003090Build and platform-specific issues
3091
3092- Better support of GNU Pth via --with-pth configure option.
3093
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003094- Python/C API now properly exposed to dynamically-loaded extension
3095 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003096
3097- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3098 Don't define MS_SYNC to be zero when it is undefined. Added missing
3099 prototypes in posixmodule.c.
3100
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003101- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003102 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003103
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003104- Fix largefile support on older NetBSD systems and OpenBSD by adding
3105 define for TELL64.
3106
3107
3108Tools and other miscellany
3109
3110- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3111
3112- freeze: The modulefinder now works with 2.0 opcodes.
3113
Tim Petersa3a3a032000-11-30 05:22:44 +00003114- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003115 Move hackery of sys.argv until after the Tk instance has been
3116 created, which allows the application-specific Tkinter
3117 initialization to be executed if present; also pass an explicit
3118 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003119
Jeremy Hylton1b618592000-09-26 05:32:36 +00003120
3121What's new in 2.0 beta 1?
3122=========================
3123
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003124Source Incompatibilities
3125------------------------
3126
3127None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3128such as single-argument append(), connect() and bind(), and changes to
3129str(long) and repr(float).
3130
3131
3132Binary Incompatibilities
3133------------------------
3134
3135- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3136with Python 2.0; these extensions will have to be rebuilt for Python
31372.0.
3138
3139- On Windows, attempting to import a third party extension built for
3140Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3141can do about this. Check your PYTHONPATH environment variable!
3142
3143- Python bytecode files (*.pyc and *.pyo) are not compatible between
3144releases.
3145
3146
3147Overview of Changes Since 1.6
3148-----------------------------
3149
3150There are many new modules (including brand new XML support through
3151the xml package, and i18n support through the gettext module); a list
3152of all new modules is included below. Lots of bugs have been fixed.
3153
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003154The process for making major new changes to the language has changed
3155since Python 1.6. Enhancements must now be documented by a Python
3156Enhancement Proposal (PEP) before they can be accepted.
3157
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003158There are several important syntax enhancements, described in more
3159detail below:
3160
3161 - Augmented assignment, e.g. x += 1
3162
3163 - List comprehensions, e.g. [x**2 for x in range(10)]
3164
3165 - Extended import statement, e.g. import Module as Name
3166
3167 - Extended print statement, e.g. print >> file, "Hello"
3168
3169Other important changes:
3170
3171 - Optional collection of cyclical garbage
3172
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003173Python Enhancement Proposal (PEP)
3174---------------------------------
3175
3176PEP stands for Python Enhancement Proposal. A PEP is a design
3177document providing information to the Python community, or describing
3178a new feature for Python. The PEP should provide a concise technical
3179specification of the feature and a rationale for the feature.
3180
3181We intend PEPs to be the primary mechanisms for proposing new
3182features, for collecting community input on an issue, and for
3183documenting the design decisions that have gone into Python. The PEP
3184author is responsible for building consensus within the community and
3185documenting dissenting opinions.
3186
3187The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003188
3189Augmented Assignment
3190--------------------
3191
3192This must have been the most-requested feature of the past years!
3193Eleven new assignment operators were added:
3194
Guido van Rossume905e952000-09-05 12:42:46 +00003195 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003196
3197For example,
3198
3199 A += B
3200
3201is similar to
3202
3203 A = A + B
3204
3205except that A is evaluated only once (relevant when A is something
3206like dict[index].attr).
3207
3208However, if A is a mutable object, A may be modified in place. Thus,
3209if A is a number or a string, A += B has the same effect as A = A+B
3210(except A is only evaluated once); but if a is a list, A += B has the
3211same effect as A.extend(B)!
3212
3213Classes and built-in object types can override the new operators in
3214order to implement the in-place behavior; the not-in-place behavior is
3215used automatically as a fallback when an object doesn't implement the
3216in-place behavior. For classes, the method name is derived from the
3217method name for the corresponding not-in-place operator by inserting
3218an 'i' in front of the name, e.g. __iadd__ implements in-place
3219__add__.
3220
3221Augmented assignment was implemented by Thomas Wouters.
3222
3223
3224List Comprehensions
3225-------------------
3226
3227This is a flexible new notation for lists whose elements are computed
3228from another list (or lists). The simplest form is:
3229
3230 [<expression> for <variable> in <sequence>]
3231
Guido van Rossum56db0952000-09-06 23:34:25 +00003232For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003233This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003234
3235You can also add a condition:
3236
3237 [<expression> for <variable> in <sequence> if <condition>]
3238
3239For example, [w for w in words if w == w.lower()] would yield the list
3240of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003241than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003242
3243You can also have nested for loops and more than one 'if' clause. For
3244example, here's a function that flattens a sequence of sequences::
3245
3246 def flatten(seq):
3247 return [x for subseq in seq for x in subseq]
3248
3249 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3250
3251This prints
3252
3253 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3254
3255List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003256Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003257
3258
3259Extended Import Statement
3260-------------------------
3261
3262Many people have asked for a way to import a module under a different
3263name. This can be accomplished like this:
3264
3265 import foo
3266 bar = foo
3267 del foo
3268
3269but this common idiom gets old quickly. A simple extension of the
3270import statement now allows this to be written as follows:
3271
3272 import foo as bar
3273
3274There's also a variant for 'from ... import':
3275
3276 from foo import bar as spam
3277
3278This also works with packages; e.g. you can write this:
3279
3280 import test.regrtest as regrtest
3281
3282Note that 'as' is not a new keyword -- it is recognized only in this
3283context (this is only possible because the syntax for the import
3284statement doesn't involve expressions).
3285
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003286Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003287
3288
3289Extended Print Statement
3290------------------------
3291
3292Easily the most controversial new feature, this extension to the print
3293statement adds an option to make the output go to a different file
3294than the default sys.stdout.
3295
3296For example, to write an error message to sys.stderr, you can now
3297write:
3298
3299 print >> sys.stderr, "Error: bad dog!"
3300
3301As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003302evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003303
3304 print >> None, "Hello world"
3305
3306is equivalent to
3307
3308 print "Hello world"
3309
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003310Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003311
3312
3313Optional Collection of Cyclical Garbage
3314---------------------------------------
3315
3316Python is now equipped with a garbage collector that can hunt down
3317cyclical references between Python objects. It's no replacement for
3318reference counting; in fact, it depends on the reference counts being
3319correct, and decides that a set of objects belong to a cycle if all
3320their reference counts can be accounted for from their references to
3321each other. This devious scheme was first proposed by Eric Tiedemann,
3322and brought to implementation by Neil Schemenauer.
3323
3324There's a module "gc" that lets you control some parameters of the
3325garbage collection. There's also an option to the configure script
3326that lets you enable or disable the garbage collection. In 2.0b1,
3327it's on by default, so that we (hopefully) can collect decent user
3328experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003329performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003330off by default in the final 2.0 release.
3331
3332
3333Smaller Changes
3334---------------
3335
3336A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3337map(None, seq1, seq2, ...) when the sequences have the same length;
3338i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3339the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003340zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003341
3342sys.version_info is a tuple (major, minor, micro, level, serial).
3343
3344Dictionaries have an odd new method, setdefault(key, default).
3345dict.setdefault(key, default) returns dict[key] if it exists; if not,
3346it sets dict[key] to default and returns that value. Thus:
3347
3348 dict.setdefault(key, []).append(item)
3349
3350does the same work as this common idiom:
3351
3352 if not dict.has_key(key):
3353 dict[key] = []
3354 dict[key].append(item)
3355
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003356There are two new variants of SyntaxError that are raised for
3357indentation-related errors: IndentationError and TabError.
3358
3359Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3360escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003361
3362The limits on the size of expressions and file in Python source code
3363have been raised from 2**16 to 2**32. Previous versions of Python
3364were limited because the maximum argument size the Python VM accepted
3365was 2**16. This limited the size of object constructor expressions,
3366e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3367limit was raised thanks to a patch by Charles Waldman that effectively
3368fixes the problem. It is now much more likely that you will be
3369limited by available memory than by an arbitrary limit in Python.
3370
3371The interpreter's maximum recursion depth can be modified by Python
3372programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3373limit is the maximum number of recursive calls that can be made by
3374Python code. The limit exists to prevent infinite recursion from
3375overflowing the C stack and causing a core dump. The default value is
33761000. The maximum safe value for a particular platform can be found
3377by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003378
3379New Modules and Packages
3380------------------------
3381
3382atexit - for registering functions to be called when Python exits.
3383
3384imputil - Greg Stein's alternative API for writing custom import
3385hooks.
3386
3387pyexpat - an interface to the Expat XML parser, contributed by Paul
3388Prescod.
3389
3390xml - a new package with XML support code organized (so far) in three
3391subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3392would fill a volume. There's a special feature whereby a
3393user-installed package named _xmlplus overrides the standard
3394xmlpackage; this is intended to give the XML SIG a hook to distribute
3395backwards-compatible updates to the standard xml package.
3396
3397webbrowser - a platform-independent API to launch a web browser.
3398
3399
Guido van Rossume905e952000-09-05 12:42:46 +00003400Changed Modules
3401---------------
3402
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003403array -- new methods for array objects: count, extend, index, pop, and
3404remove
3405
3406binascii -- new functions b2a_hex and a2b_hex that convert between
3407binary data and its hex representation
3408
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003409calendar -- Many new functions that support features including control
3410over which day of the week is the first day, returning strings instead
3411of printing them. Also new symbolic constants for days of week,
3412e.g. MONDAY, ..., SUNDAY.
3413
3414cgi -- FieldStorage objects have a getvalue method that works like a
3415dictionary's get method and returns the value attribute of the object.
3416
3417ConfigParser -- The parser object has new methods has_option,
3418remove_section, remove_option, set, and write. They allow the module
3419to be used for writing config files as well as reading them.
3420
3421ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003422optionally support the RFC 959 REST command.
3423
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003424gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003425
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003426httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3427the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003428
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003429locale -- implement getdefaultlocale for Win32 and Macintosh
3430
3431marshal -- no longer dumps core when marshaling deeply nested or
3432recursive data structures
3433
3434os -- new functions isatty, seteuid, setegid, setreuid, setregid
3435
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003436os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3437support under Unix.
3438
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003439os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003440
3441os.path -- fix semantics of os.path.commonprefix
3442
3443smtplib -- support for sending very long messages
3444
3445socket -- new function getfqdn()
3446
3447readline -- new functions to read, write and truncate history files.
3448The readline section of the library reference manual contains an
3449example.
3450
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003451select -- add interface to poll system call
3452
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003453shutil -- new copyfileobj function
3454
3455SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3456HTTP server.
3457
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003458Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003459
3460urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003461e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003462
3463whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003464
3465
3466Obsolete Modules
3467----------------
3468
3469None. However note that 1.6 made a whole slew of modules obsolete:
3470stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3471poly, zmod, strop, util, whatsound.
3472
3473
3474Changed, New, Obsolete Tools
3475----------------------------
3476
Tim Peters8b092332000-09-05 20:15:25 +00003477None.
Guido van Rossume905e952000-09-05 12:42:46 +00003478
3479
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003480C-level Changes
3481---------------
3482
3483Several cleanup jobs were carried out throughout the source code.
3484
3485All C code was converted to ANSI C; we got rid of all uses of the
3486Py_PROTO() macro, which makes the header files a lot more readable.
3487
3488Most of the portability hacks were moved to a new header file,
3489pyport.h; several other new header files were added and some old
3490header files were removed, in an attempt to create a more rational set
3491of header files. (Few of these ever need to be included explicitly;
3492they are all included by Python.h.)
3493
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003494Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003495and Win64, especially for the new Intel Itanium processor. Mick also
3496added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003497
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003498The C APIs to return an object's size have been update to consistently
3499use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3500previous versions, the abstract interfaces used PyXXX_Length and the
3501concrete interfaces used PyXXX_Size. The old names,
3502e.g. PyObject_Length, are still available for backwards compatibility
3503at the API level, but are deprecated.
3504
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003505The PyOS_CheckStack function has been implemented on Windows by
3506Fredrik Lundh. It prevents Python from failing with a stack overflow
3507on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003508
3509The GC changes resulted in creation of two new slots on object,
3510tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003511the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003512
3513The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003514C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003515
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003516PyErr_Format has been updated to automatically calculate the size of
3517the buffer needed to hold the formatted result string. This change
3518prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003519
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003520New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003521
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003522PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3523that are the same as their non-Ex counterparts except they take an
3524extra flag argument that tells them to close the file when done.
3525
3526XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003527
Tim Peters8b092332000-09-05 20:15:25 +00003528
3529Windows Changes
3530---------------
3531
3532New popen2/popen3/peopen4 in os module (see Changed Modules above).
3533
3534os.popen is much more usable on Windows 95 and 98. See Microsoft
3535Knowledge Base article Q150956. The Win9x workaround described there
3536is implemented by the new w9xpopen.exe helper in the root of your
3537Python installation. Note that Python uses this internally; it is not
3538a standalone program.
3539
3540Administrator privileges are no longer required to install Python
3541on Windows NT or Windows 2000. If you have administrator privileges,
3542Python's registry info will be written under HKEY_LOCAL_MACHINE.
3543Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003544under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003545uses of Python, but will prevent some advanced uses from working
3546(for example, running a Python script as an NT service, or possibly
3547from CGI).
3548
3549[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3550installer; instead, it installs the needed Tcl/Tk files directly in the
3551Python directory. If you already have a Tcl/Tk installation, this
3552wastes some disk space (about 4 Megs) but avoids problems with
3553conflicting Tcl/Tk installations, and makes it much easier for Python
3554to ensure that Tcl/Tk can find all its files.
3555
3556[This was new in 1.6] The Windows installer now installs by default in
3557\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3558
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003559
3560Updates to the changes between 1.5.2 and 1.6
3561--------------------------------------------
3562
3563The 1.6 NEWS file can't be changed after the release is done, so here
3564is some late-breaking news:
3565
3566New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3567and changes to getlocale() and setlocale().
3568
3569The new module is now enabled per default.
3570
3571It is not true that the encodings codecs cannot be used for normal
3572strings: the string.encode() (which is also present on 8-bit strings
3573!) allows using them for 8-bit strings too, e.g. to convert files from
3574cp1252 (Windows) to latin-1 or vice-versa.
3575
3576Japanese codecs are available from Tamito KAJIYAMA:
3577http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3578
3579
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003580======================================================================