blob: b4ac86e999d9f15f7c1f75df17ab895e160a7a4c [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
Tim Petersf47630f2002-08-01 02:34:51 +00009- list.sort() has a new implementation. While cross-platform results
10 may vary, and in data-dependent ways, this is much faster on many
11 kinds of partially ordered lists than the previous implementation,
12 and reported to be just as fast on randomly ordered lists on
13 several major platforms. This sort is also stable (if A==B and A
14 precedes B in the list at the start, A precedes B after the sort too),
15 although the language definition does not guarantee stability. A
16 potential drawback is that list.sort() may require temp space of
17 len(list)*2 bytes (*4 on a 64-bit machine). It's therefore possible
18 for list.sort() to raise MemoryError now, even if a comparison function
19 does not. See <http://www.python.org/sf/587076> for full details.
20
Guido van Rossum2d5389c2002-07-23 03:44:35 +000021- All standard iterators now ensure that, once StopIteration has been
22 raised, all future calls to next() on the same iterator will also
23 raise StopIteration. There used to be various counterexamples to
24 this behavior, which could caused confusion or subtle program
25 breakage, without any benefits. (Note that this is still an
26 iterator's responsibility; the iterator framework does not enforce
27 this.)
28
Mark Hammondc0e35152002-07-16 01:32:30 +000029- Ctrl+C handling on Windows has been made more consistent with
30 other platforms. KeyboardInterrupt can now reliably be caught,
Tim Petersf47630f2002-08-01 02:34:51 +000031 and Ctrl+C at an interative prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +000032 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Petersf47630f2002-08-01 02:34:51 +000033 interrupt time.sleep() in the main thread, and any child processes
34 created via the popen family are also interrupted (as generally
Mark Hammondc0e35152002-07-16 01:32:30 +000035 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
36
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000037- Slices and repetitions of buffer objects now consistently return
38 a string. Formerly, strings would be returned most of the time,
39 but a buffer object would be returned when the repetition count
40 was one or when the slice range was all inclusive.
41
Guido van Rossumc7c36502002-06-21 01:29:25 +000042- The __slots__ variable can now mention "private" names, and the
43 right thing will happen (e.g. __slots__ = ["__foo"]).
44
Walter Dörwald3430d702002-06-17 10:43:59 +000045- Unicode objects in sys.path are no longer ignored but treated
46 as directory names.
47
Guido van Rossum9562bcf2002-06-14 21:31:18 +000048- The built-ins slice() and buffer() are now callable types. The
49 types classobj (formerly class), code, function, instance, and
50 instancemethod (formerly instance-method), which have no built-in
51 names but are accessible through the types module, are now also
52 callable. The type dict-proxy is renamed to dictproxy.
53
Neal Norwitz1f68fc72002-06-14 00:50:42 +000054- Fixed string.startswith and string.endswith builtin methods
55 so they accept negative indices. [SF bug 493951]
56
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000057- Fixed a bug with a continue inside a try block and a yield in the
58 finally clause. [SF bug 567538]
59
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000060- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000061 with a third "stride" parameter. For example, "hello world"[::-1]
62 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000063
Guido van Rossum9f7549b2002-06-10 21:39:42 +000064- Cycles going through the __class__ link of a new-style instance are
65 now detected by the garbage collector.
66
Guido van Rossum9923ffe2002-06-04 19:52:53 +000067- Classes using __slots__ are now properly garbage collected.
68 [SF bug 519621]
69
70- Tightened the __slots__ rules: a slot name must be a valid Python
71 identifier.
72
Guido van Rossum2e4e0262002-06-04 05:58:34 +000073- The constructor for the module type now requires a name argument and
74 takes an optional docstring argument. Previously, this constructor
75 ignored its arguments. As a consequence, deriving a class from a
76 module (not from the module type) is now illegal; previously this
77 created an unnamed module, just like invoking the module type did.
78 [SF bug 563060]
79
Neal Norwitzd68f5172002-05-29 15:54:55 +000080- A new warning PendingDeprecationWarning was added to provide
81 direction on features which are in the process of being deprecated.
82 The warning will not be printed by default. To see the pending
83 deprecations, use -Walways::PendingDeprecationWarning::
84 as a command line option or warnings.filterwarnings() in code.
85
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000086- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000087 for 'str' and 'unicode', and can be used instead of
88 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000089 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000090 is an abstract base class and cannot be instantiated directly.
91
Fred Draked0ba6362002-05-02 21:28:26 +000092- Deprecated features of xrange objects have been removed as
93 promised. The start, stop, and step attributes and the tolist()
94 method no longer exist. xrange repetition and slicing have been
95 removed.
96
Guido van Rossum7dab2422002-04-26 19:40:56 +000097- New builtin function enumerate(x), from PEP 279. Example:
98 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
99 The argument can be an arbitrary iterable object.
100
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000101- The assert statement no longer tests __debug__ at runtime. This means
102 that assert statements cannot be disabled by assigning a false value
103 to __debug__.
104
Walter Dörwald068325e2002-04-15 13:36:47 +0000105- A method zfill() was added to str and unicode, that fills a numeric
106 string to the left with zeros. For example,
107 "+123".zfill(6) -> "+00123".
108
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000109- Complex numbers supported divmod() and the // and % operators, but
110 these make no sense. Since this was documented, they're being
111 deprecated now.
112
Guido van Rossum26dd8302002-04-26 20:11:29 +0000113- String and unicode methods lstrip(), rstrip() and strip() now take
114 an optional argument that specifies the characters to strip. For
115 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000116
Guido van Rossumc69343b2002-04-12 19:22:48 +0000117- Added a new dict method pop(key). This removes and returns the
118 value corresponding to key. [SF patch #539949]
119
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000120- Changed new-style class instantiation so that when C's __new__
121 method returns something that's not a C instance, its __init__ is
122 not called. [SF bug #537450]
123
Guido van Rossum181e41a2002-04-06 00:23:25 +0000124- Fixed super() to work correctly with class methods. [SF bug #535444]
125
Guido van Rossum47834462002-04-04 15:21:33 +0000126- A new built-in type, bool, has been added, as well as built-in
127 names for its two values, True and False. Comparisons and sundry
128 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000129 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000130 is backward compatible.
131
Guido van Rossum95b62a62002-03-29 01:07:24 +0000132- Fixed two bugs reported as SF #535905: under certain conditions,
133 deallocating a deeply nested structure could cause a segfault in the
134 garbage collector, due to interaction with the "trashcan" code;
135 access to the current frame during destruction of a local variable
136 could access a pointer to freed memory.
137
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000138- The optional object allocator ("pymalloc") has been enabled by
139 default. The recommended practice for memory allocation and
140 deallocation has been streamlined. A header file is included,
141 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
142 and lets them use the same API with Python versions from 1.5.2
143 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000144
Guido van Rossum8c842552002-03-14 23:05:54 +0000145- If you try to pickle an instance of a class that has __slots__ but
146 doesn't define or override __getstate__, a TypeError is now raised.
147 This is done by adding a bozo __getstate__ to the class that always
148 raises TypeError. (Before, this would appear to be pickled, but the
149 state of the slots would be lost.)
150
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000151- PyErr_Display will provide file and line information for all exceptions
152 that have an attribute print_file_and_line, not just SyntaxErrors.
153
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000154- The UTF-8 codec will now encode and decode Unicode surrogates
155 correctly and without raising exceptions for unpaired ones.
156
Neal Norwitz649b7592002-01-01 19:07:13 +0000157- file.xreadlines() now raises a ValueError if the file is closed:
158 Previously, an xreadlines object was returned which would raise
159 a ValueError when the xreadlines.next() method was called.
160
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000161- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000162 An exception will now be raised if more than one argument is used.
163
Tim Petersaf8446f2001-12-21 21:36:50 +0000164Extension modules
165
Guido van Rossum79f0a102002-07-23 03:32:08 +0000166- The strptime function in the time module is now always available (a
167 Python implementation is used when the C library doesn't define it).
168
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000169- The 'new' module is no longer an extension, but a Python module that
170 only exists for backwards compatibility. Its contents are no longer
171 functions but callable type objects.
172
Tim Peters81b92512002-04-29 01:37:32 +0000173- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000174 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000175 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000176
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000177- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
178 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000179
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000180- The locale module now exposes the C library's gettext interface.
181
Tim Petersfbf74f22002-03-14 19:06:01 +0000182- A security hole ("double free") was found in zlib-1.1.3, a popular
183 third party compression library used by some Python modules. The
184 hole was quickly plugged in zlib-1.1.4, and the Windows build of
185 Python now ships with zlib-1.1.4.
186
Martin v. Löwis688357e2002-04-08 21:28:20 +0000187- pwd, grp, and resource return enhanced tuples now, with symbolic
188 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000189
Martin v. Löwis99866332002-03-01 10:27:01 +0000190- array.array is now a type object. A new format character
191 'u' indicates Py_UNICODE arrays. For those, .tounicode and
192 .fromunicode methods are available. Arrays now support __iadd__
193 and __imul__.
194
Neal Norwitze790eae2002-01-01 21:14:12 +0000195- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000196 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
197 is called.
198
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000199- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
200 been added where available.
201
Tim Petersaf8446f2001-12-21 21:36:50 +0000202Library
203
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000204- New encoding for the Palm OS character set: palmos.
205
Tim Peters943382c2002-07-07 03:59:34 +0000206- binascii.crc32() and the zipfile module had problems on some 64-bit
207 platforms. These have been fixed. On a platform with 8-byte C longs,
208 crc32() now returns a signed-extended 4-byte result, so that its value
209 as a Python int is equal to the value computed a 32-bit platform.
210
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000211- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
212 argument.
213
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000214- Some fixes in the copy module: when an object is copied through its
215 __reduce__ method, there was no check for a __setstate__ method on
216 the result [SF patch 565085]; deepcopy should treat instances of
217 custom metaclasses the same way it treats instances of type 'type'
218 [SF patch 560794].
219
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000220- Sockets now support timeout mode. After s.settimeout(T), where T is
221 a float expressing seconds, subsequent operations raise an exception
222 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000223 mode, use s.settimeout(None). There's also a module function,
224 socket.setdefaulttimeout(T), which sets the default for all sockets
225 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000226
227- getopt.gnu_getopt was added. This supports GNU-style option
228 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000229
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000230- Stop using strings for exceptions. String objects used for
231 exceptions are now classes deriving from Exception. The objects
232 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
233 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000234
Walter Dörwald474458d2002-06-04 15:16:29 +0000235- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
236 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
237 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
238 big endian systems were added to the codecs module. The old names
239 BOM32_* and BOM64_* were off by a factor of 2.
240
Guido van Rossumf9257822002-06-18 20:43:18 +0000241- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000242
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000243- ftplib.retrlines() now tests for callback is None rather than testing
244 for False. Was causing an error when given a callback object which
245 was callable but also returned len() as zero. The change may
246 create new breakage if the caller relied on the undocumented behavior
247 and called with callback set to [] or some other False value not
248 identical to None.
249
Tim Peters46c04e12002-05-05 20:40:00 +0000250- random.gauss() uses a piece of hidden state used by nothing else,
251 and the .seed() and .whseed() methods failed to reset it. In other
252 words, setting the seed didn't completely determine the sequence of
253 results produced by random.gauss(). It does now. Programs repeatedly
254 mixing calls to a seed method with calls to gauss() may see different
255 results now.
256
Fred Drake7f781c92002-05-01 20:33:53 +0000257- The pickle.Pickler class grew a clear_memo() method to mimic that
258 provided by cPickle.Pickler.
259
Tim Peters81b92512002-04-29 01:37:32 +0000260- difflib's SequenceMatcher class now does a dynamic analysis of
261 which elements are so frequent as to constitute noise. For
262 comparing files as sequences of lines, this generally works better
263 than the IS_LINE_JUNK function, and function ndiff's linejunk
264 argument defaults to None now as a result. A happy benefit is
265 that SequenceMatcher may run much faster now when applied
266 to large files with many duplicate lines (for example, C program
267 text with lots of repeated "}" and "return NULL;" lines).
268
Guido van Rossum256705b2002-04-23 13:29:43 +0000269- New Text.dump() method in Tkinter module.
270
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000271- New distutils commands for building packagers were added to
272 support pkgtool on Solaris and swinstall on HP-UX.
273
274- distutils now has a new abstract binary packager base class
275 command/bdist_packager, which simplifies writing packagers.
276 This will hopefully provide the missing bits to encourage
277 people to submit more packagers, e.g. for Debian, FreeBSD
278 and other systems.
279
Guido van Rossumf9257822002-06-18 20:43:18 +0000280- The UTF-16, -LE and -BE stream readers now raise a
281 NotImplementedError for all calls to .readline(). Previously, they
282 used to just produce garbage or fail with an encoding error --
283 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 +0000284 work well with these.
285
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000286- compileall now supports quiet operation.
287
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000288- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000289 connections.
290
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000291- socket module: the SSL support was broken out of the main
292 _socket module C helper and placed into a new _ssl helper
293 which now gets imported by socket.py if available and working.
294
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000295- encodings package: added aliases for all supported IANA character
296 sets
297
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000298- ftplib: to safeguard the user's privacy, anonymous login will use
299 "anonymous@" as default password, rather than the real user and host
300 name.
301
Fred Drake36736122002-01-10 13:50:31 +0000302- webbrowser: tightened up the command passed to os.system() so that
303 arbitrary shell code can't be executed because a bogus URL was
304 passed in.
305
Tim Peters11bd9942002-02-01 00:52:29 +0000306- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000307 gettext.find an optional all argument. Translations will now fallback
308 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000309
Martin v. Löwis9668b932002-01-12 11:27:42 +0000310- distutils bdist commands now offer a --skip-build option.
311
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000312- warnings.warn now accepts a Warning instance as first argument.
313
Fred Drakefed7e852002-04-04 19:36:15 +0000314- The xml.sax.expatreader.ExpatParser class will no longer create
315 circular references by using itself as the locator that gets passed
316 to the content handler implementation. [SF bug #535474]
317
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000318- The email.Parser.Parser class now properly parses strings regardless
319 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
320 or CRLF). Also, the Header class's constructor default arguments
321 has changed slightly so that an explicit maxlinelen value is always
322 honored.
323
Tim Petersaf8446f2001-12-21 21:36:50 +0000324Tools/Demos
325
Marc-André Lemburg46260092002-04-04 16:17:11 +0000326- freeze.py now produces binaries which can import shared modules,
327 unlike before when this failed due to missing symbol exports in
328 the generated binary.
329
Tim Petersaf8446f2001-12-21 21:36:50 +0000330Build
331
Tim Petersf47630f2002-08-01 02:34:51 +0000332- The public Python C API will generally be declared using PyAPI_FUNC
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000333 and PyAPI_DATA macros, while Python extension module init functions
334 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
335 are deprecated.
336
Tim Petersc6a3ff62002-07-08 22:11:52 +0000337- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
338 get into infinite loops, when a new-style class got garbage-collected.
339 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
340 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
341 COUNT_ALLOCS is not enabled by default, in either release or debug
342 builds, and that new-style classes are immortal only in COUNT_ALLOCS
343 builds.
344
Tim Peters943382c2002-07-07 03:59:34 +0000345- Compiling out the cyclic garbage collector is no longer an option.
346 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
347 that it's always defined (for the benefit of any extension modules
348 that may be conditionalizing on it). A bonus is that any extension
349 type participating in cyclic gc can choose to participate in the
350 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
351 to require editing the core to teach the trashcan mechanism about the
352 new type.
353
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000354- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000355
356 The Standard C macro HUGE_VAL and its float and long double analogs,
357 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
358 positive infinities.
359
360 Python only uses the double HUGE_VAL, and only to #define its own symbol
361 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
362 pyport.h used to try to worm around that, but the workarounds triggered
363 other bugs on other platforms, so we gave up. If your platform defines
364 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
365 that works on your platform. The only instance of this I'm sure about
366 is on an unknown subset of Cray systems, described here:
367
368 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
369
370 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
371
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000372- The configure option --without-doc-strings can be used to remove the
373 doc strings from the builtin functions and modules; this reduces the
374 size of the executable.
375
Tim Peters639295f2002-04-21 07:30:30 +0000376- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
377 say how or when to configure it, or how to turn it off.
378
Martin v. Löwis1142de32002-03-29 16:28:31 +0000379- On Unix, a shared libpython2.3.so can be created with --enable-shared.
380
Tim Peters8deda702002-03-30 10:06:07 +0000381- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
382 preprocessor symbols were eliminated. The internal decisions they
383 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000384
Fred Drake7d28b732002-05-02 21:17:00 +0000385- The tools used to build the documentation now work under Cygwin as
386 well as Unix.
387
Skip Montanaro57454e52002-06-14 20:30:31 +0000388- The bsddb and dbm module builds have been changed to try and avoid version
389 skew problems and disable linkage with Berkeley DB 1.85 unless the
390 installer knows what s/he's doing. See the section on building these
391 modules in the README file for details.
392
Tim Petersaf8446f2001-12-21 21:36:50 +0000393C API
394
Thomas Heller085358a2002-07-29 14:27:41 +0000395- New functions PyErr_SetExcFromWindowsErr() and
396 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
397 PyErr_SetFromWindowsErrWithFilename() and
398 PyErr_SetFromWindowsErr(), but they allow to specify
399 the exception type to raise. Available on Windows.
400
Tim Peters7c321a82002-07-09 02:57:01 +0000401- Py_FatalError() is now declared as taking a const char* argument. It
402 was previously declared without const. This should not affect working
403 code.
404
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000405- Added new macro PySequence_ITEM(o, i) that directly calls
406 sq_item without rechecking that o is a sequence and without
407 adjusting for negative indices.
408
Fred Draked0ba6362002-05-02 21:28:26 +0000409- PyRange_New() now raises ValueError if the fourth argument is not 1.
410 This is part of the removal of deprecated features of the xrange
411 object.
412
Guido van Rossum517c7d42002-04-26 02:49:14 +0000413- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
414 coercion if both arguments have the same type but this type has the
415 CHECKTYPES flag set. This is to better support proxies.
416
Neil Schemenauer9344b142002-04-12 23:00:08 +0000417- The type of tp_free has been changed from "void (*)(PyObject *)" to
418 "void (*)(void *)".
419
420- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
421
Guido van Rossum0986d822002-04-08 01:38:42 +0000422- A type can now inherit its metatype from its base type. Previously,
423 when PyType_Ready() was called, if ob_type was found to be NULL, it
424 was always set to &PyType_Type; now it is set to base->ob_type,
425 where base is tp_base, defaulting to &PyObject_Type.
426
427- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
428
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000429- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000430
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000431- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000432 without going through the buffer API.
433
Martin v. Löwis7198a522002-01-01 19:59:11 +0000434- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
435
Tim Peters10a3bb52001-12-25 19:07:38 +0000436- An old #define of ANY as void has been removed from pyport.h. This
437 hasn't been used since Python's pre-ANSI days, and the #define has
438 been marked as obsolete since then. SF bug 495548 says it created
439 conflicts with other packages, so keeping it around wasn't harmless.
440
Tim Petersaf8446f2001-12-21 21:36:50 +0000441- Because Python's magic number scheme broke on January 1st, we decided
442 to stop Python development. Thanks for all the fish!
443
Tim Petersfb05db22002-03-11 00:24:00 +0000444- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000445 scheme to a new one. See Python/import.c for details.
446
Tim Petersaf8446f2001-12-21 21:36:50 +0000447New platforms
448
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000449- AtheOS is now supported.
450
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000451- GNU/Hurd is now supported.
452
Tim Petersaf8446f2001-12-21 21:36:50 +0000453Tests
454
455Windows
456
Tim Peters08e72952002-04-16 20:48:01 +0000457- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
458 of that has been fixed in the installer (disabled Wise's "delete in-
459 use files" uninstall option).
460
Guido van Rossum181e41a2002-04-06 00:23:25 +0000461- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
462
Tim Peters33187922002-04-04 20:02:04 +0000463- The installer now installs Start menu shortcuts under (the local
464 equivalent of) "All Users" when doing an Admin install.
465
Tim Petersfb05db22002-03-11 00:24:00 +0000466- file.truncate([newsize]) now works on Windows for all newsize values.
467 It used to fail if newsize didn't fit in 32 bits, reflecting a
468 limitation of MS _chsize (which is no longer used).
469
Tim Petersab034fa2002-02-01 11:27:43 +0000470- os.waitpid() is now implemented for Windows, and can be used to block
471 until a specified process exits. This is similar to, but not exactly
472 the same as, os.waitpid() on POSIX systems. If you're waiting for
473 a specific process whose pid was obtained from one of the spawn()
474 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000475 See the docs for details. The docs were changed to clarify that
476 spawn functions return, and waitpid requires, a process handle on
477 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000478
Tim Peters11bd9942002-02-01 00:52:29 +0000479- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000480 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000481 to a nasty problem: before 2.3, if you got a temp file on Windows, it
482 got wrapped in an object whose close() method first closed the
483 underlying file, then deleted the file. This usually worked fine.
484 However, the spawn family of functions on Windows create (at a low C
485 level) the same set of open files in the spawned process Q as were
486 open in the spawning process P. If a temp file f was among them, then
487 doing f.close() in P first closed P's C-level file handle on f, but Q's
488 C-level file handle on f remained open, so the attempt in P to delete f
489 blew up with a "Permission denied" error (Windows doesn't allow
490 deleting open files). This was surprising, subtle, and difficult to
491 work around.
492
493- The os module now exports all the symbolic constants usable with the
494 low-level os.open() on Windows: the new constants in 2.3 are
495 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
496 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
497 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
498 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
499 (so specify both if you want both; note that neither is useful unless
500 specified with O_CREAT too).
501
Tim Petersaf8446f2001-12-21 21:36:50 +0000502Mac
503
504
Tim Peters909c0912001-12-14 23:16:18 +0000505What's New in Python 2.2 final?
506Release date: 21-Dec-2001
507===============================
508
509Type/class unification and new-style classes
510
Barry Warsaw52acb492001-12-21 20:04:22 +0000511- pickle.py, cPickle: allow pickling instances of new-style classes
512 with a custom metaclass.
513
Tim Peters909c0912001-12-14 23:16:18 +0000514Core and builtins
515
Barry Warsaw52acb492001-12-21 20:04:22 +0000516- weakref proxy object: when comparing, unwrap both arguments if both
517 are proxies.
518
Tim Peters909c0912001-12-14 23:16:18 +0000519Extension modules
520
Barry Warsaw52acb492001-12-21 20:04:22 +0000521- binascii.b2a_base64(): fix a potential buffer overrun when encoding
522 very short strings.
523
524- cPickle: the obscure "fast" mode was suspected of causing stack
525 overflows on the Mac. Hopefully fixed this by setting the recursion
526 limit much smaller. If the limit is too low (it only affects
527 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
528 when compiling cPickle.c (or in pyconfig.h).
529
Tim Peters909c0912001-12-14 23:16:18 +0000530Library
531
Barry Warsaw52acb492001-12-21 20:04:22 +0000532- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
533 close or delete time).
534
535- rfc822.py: fixed a bug where the address '<>' was converted to None
536 instead of an empty string (also fixes the email.Utils module).
537
538- xmlrpclib.py: version 1.0.0; uses precision for doubles.
539
540- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000541 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000542
Tim Peters909c0912001-12-14 23:16:18 +0000543Tools/Demos
544
545Build
546
547C API
548
549New platforms
550
551Tests
552
553Windows
554
Barry Warsaw52acb492001-12-21 20:04:22 +0000555- distutils package: fixed broken Windows installers (bdist_wininst).
556
557- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
558 instances are deleted at process exit time.
559
560- socket.py: prevent mysterious warnings when socket instances are
561 deleted at process exit time.
562
563- posixmodule.c: fix a Windows crash with stat() of a filename ending
564 in backslash.
565
Tim Peters909c0912001-12-14 23:16:18 +0000566Mac
567
Barry Warsaw52acb492001-12-21 20:04:22 +0000568- The Carbon toolbox modules have been upgraded to Universal Headers
569 3.4, and experimental CoreGraphics and CarbonEvents modules have
570 been added. All only for framework-enabled MacOSX.
571
Tim Peters909c0912001-12-14 23:16:18 +0000572
Tim Peters6272dfd2001-12-13 19:34:00 +0000573What's New in Python 2.2c1?
574Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000575===========================
576
577Type/class unification and new-style classes
578
Barry Warsaw06557452001-12-14 20:47:12 +0000579- Guido's tutorial introduction to the new type/class features has
580 been extensively updated. See
581
582 http://www.python.org/2.2/descrintro.html
583
584 That remains the primary documentation in this area.
585
Guido van Rossum33bab012001-12-05 22:45:48 +0000586- Fixed a leak: instance variables declared with __slots__ were never
587 deleted!
588
Guido van Rossum4b800852001-12-03 00:54:52 +0000589- The "delete attribute" method of descriptor objects is called
590 __delete__, not __del__. In previous releases, it was mistakenly
591 called __del__, which created an unfortunate overloading condition
592 with finalizers. (The "get attribute" and "set attribute" methods
593 are still called __get__ and __set__, respectively.)
594
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000595- Some subtle issues with the super built-in were fixed:
596
597 (a) When super itself is subclassed, its __get__ method would still
598 return an instance of the base class (i.e., of super).
599
600 (b) super(C, C()).__class__ would return C rather than super. This
601 is confusing. To fix this, I decided to change the semantics of
602 super so that it only applies to code attributes, not to data
603 attributes. After all, overriding data attributes is not
604 supported anyway.
605
606 (c) The __get__ method didn't check whether the argument was an
607 instance of the type used in creation of the super instance.
608
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000609- Previously, hash() of an instance of a subclass of a mutable type
610 (list or dictionary) would return some value, rather than raising
611 TypeError. This has been fixed. Also, directly calling
612 dict.__hash__ and list.__hash__ now raises the same TypeError
613 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000614
Guido van Rossumd331cb52001-12-05 19:46:42 +0000615- New-style objects now support deleting their __dict__. This is for
616 all intents and purposes equivalent to assigning a brand new empty
617 dictionary, but saves space if the object is not used further.
618
Tim Petersb3c9af12001-11-17 00:21:57 +0000619Core and builtins
620
Tim Peters3caca232001-12-06 06:23:26 +0000621- -Qnew now works as documented in PEP 238: when -Qnew is passed on
622 the command line, all occurrences of "/" use true division instead
623 of classic division. See the PEP for details. Note that "all"
624 means all instances in library and 3rd-party modules, as well as in
625 your own code. As the PEP says, -Qnew is intended for use only in
626 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000627 Note that test_coercion.py in the standard Python test suite fails
628 under -Qnew; this is expected, and won't be repaired until true
629 division becomes the default (in the meantime, test_coercion is
630 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000631
Fred Drake6c01e252001-12-14 17:08:12 +0000632- complex() now only allows the first argument to be a string
633 argument, and raises TypeError if either the second arg is a string
634 or if the second arg is specified when the first is a string.
635
Tim Petersb3c9af12001-11-17 00:21:57 +0000636Extension modules
637
Martin v. Löwis560da622001-11-24 09:24:51 +0000638- gc.get_referents was renamed to gc.get_referrers.
639
Tim Petersb3c9af12001-11-17 00:21:57 +0000640Library
641
Tim Peters25059d32001-12-07 20:35:43 +0000642- Functions in the os.spawn() family now release the global interpreter
643 lock around calling the platform spawn. They should always have done
644 this, but did not before 2.2c1. Multithreaded programs calling
645 an os.spawn function with P_WAIT will no longer block all Python threads
646 until the spawned program completes. It's possible that some programs
647 relies on blocking, although more likely by accident than by design.
648
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000649- webbrowser defaults to netscape.exe on OS/2 now.
650
Martin v. Löwis652e1912001-11-25 14:50:56 +0000651- Tix.ResizeHandle exposes detach_widget, hide, and show.
652
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000653- The charset alias windows_1252 has been added.
654
Barry Warsaw06557452001-12-14 20:47:12 +0000655- types.StringTypes is a tuple containing the defined string types;
656 usually this will be (str, unicode), but if Python was compiled
657 without Unicode support it will be just (str,).
658
659- The pulldom and minidom modules were synchronized to PyXML.
660
Tim Petersb3c9af12001-11-17 00:21:57 +0000661Tools/Demos
662
Barry Warsaw06557452001-12-14 20:47:12 +0000663- A new script called Tools/scripts/google.py was added, which fires
664 off a search on Google.
665
Tim Petersb3c9af12001-11-17 00:21:57 +0000666Build
667
Barry Warsaw06557452001-12-14 20:47:12 +0000668- Note that release builds of Python should arrange to define the
669 preprocessor symbol NDEBUG on the command line (or equivalent).
670 In the 2.2 pre-release series we tried to define this by magic in
671 Python.h instead, but it proved to cause problems for extension
672 authors. The Unix, Windows and Mac builds now all define NDEBUG in
673 release builds via cmdline (or equivalent) instead. Ports to
674 other platforms should do likewise.
675
Jack Jansen1999ef42001-12-06 21:47:20 +0000676- It is no longer necessary to use --with-suffix when building on a
677 case-insensitive file system (such as Mac OS X HFS+). In the build
678 directory an extension is used, but not in the installed python.
679
Tim Petersb3c9af12001-11-17 00:21:57 +0000680C API
681
Tim Petersf582b822001-12-11 18:51:08 +0000682- New function PyDict_MergeFromSeq2() exposes the builtin dict
683 constructor's logic for updating a dictionary from an iterable object
684 producing key-value pairs.
685
Tim Peterscffed4b2001-11-29 03:26:37 +0000686- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000687 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000688 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
689 dump core in some bad cases. This has been repaired. As a result,
690 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
691 previously went unchallenged.
692
Tim Petersb3c9af12001-11-17 00:21:57 +0000693New platforms
694
695Tests
696
697Windows
698
699Mac
700
Jack Jansenffa260f2001-12-06 21:14:00 +0000701- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
702 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000703
Barry Warsaw06557452001-12-14 20:47:12 +0000704- Changed logic for finding python home in Mac OS X framework Pythons.
705 Now sys.executable points to the executable again, in stead of to
706 the shared library. The latter is used only for locating the python
707 home.
708
709
Tim Peters84362bc2001-10-19 17:55:30 +0000710What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000711Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000712===========================
713
714Type/class unification and new-style classes
715
Guido van Rossum3d27df02001-11-15 20:27:54 +0000716- Multiple inheritance mixing new-style and classic classes in the
717 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000718
719 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000720 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000721
722 The MRO (method resolution order) for each base class is respected
723 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000724 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000725 This needs to be documented.
726
Tim Petersa427a2b2001-10-29 22:25:45 +0000727- The new builtin dictionary() constructor, and dictionary type, have
728 been renamed to dict. This reflects a decade of common usage.
729
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000730- dict() now accepts an iterable object producing 2-sequences. For
731 example, dict(d.items()) == d for any dictionary d. The argument,
732 and the elements of the argument, can be any iterable objects.
733
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000734- New-style classes can now have a __del__ method, which is called
735 when the instance is deleted (just like for classic classes).
736
Guido van Rossum12d955c2001-10-26 14:56:06 +0000737- Assignment to object.__dict__ is now possible, for objects that are
738 instances of new-style classes that have a __dict__ (unless the base
739 class forbids it).
740
Guido van Rossumc8e56452001-10-22 00:43:43 +0000741- Methods of built-in types now properly check for keyword arguments
742 (formerly these were silently ignored). The only built-in methods
743 that take keyword arguments are __call__, __init__ and __new__.
744
Guido van Rossum86443212001-10-27 22:28:54 +0000745- The socket function has been converted to a type; see below.
746
Tim Peters84362bc2001-10-19 17:55:30 +0000747Core and builtins
748
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000749- Assignment to __debug__ raises SyntaxError at compile-time. This
750 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000751 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000752
Guido van Rossum12d955c2001-10-26 14:56:06 +0000753- Clarified the error messages for unsupported operands to an operator
754 (like 1 + '').
755
Tim Peters84362bc2001-10-19 17:55:30 +0000756Extension modules
757
Tim Peters5ebfd362001-11-13 23:11:19 +0000758- mmap has a new keyword argument, "access", allowing a uniform way for
759 both Windows and Unix users to create read-only, write-through and
760 copy-on-write memory mappings. This was previously possible only on
761 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000762 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000763 platforms. Thanks to Jay T Miller for repairing this!
764
Tim Peters169ded02001-11-03 19:57:21 +0000765- By default, the gc.garbage list now contains only those instances in
766 unreachable cycles that have __del__ methods; in 2.1 it contained all
767 instances in unreachable cycles. "Instances" here has been generalized
768 to include instances of both new-style and old-style classes.
769
Guido van Rossum12d955c2001-10-26 14:56:06 +0000770- The socket module defines a new method for socket objects,
771 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000772 send() until all data has been sent. Also, the socket function has
773 been converted to a subclassable type, like list and tuple (etc.)
774 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000775
776- Various bugfixes to the curses module. There is now a test suite
777 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000778
Guido van Rossum692adf12001-10-30 03:03:03 +0000779- binascii.b2a_base64 no longer places an arbitrary restriction of 57
780 bytes on its input.
781
Tim Peters84362bc2001-10-19 17:55:30 +0000782Library
783
Tim Peters5ebfd362001-11-13 23:11:19 +0000784- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000785 convenience function.
786
Tim Peters75335872001-11-03 19:35:43 +0000787- Symbolic group names in regular expressions must be unique. For
788 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
789 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000790 Python 2.2 detects this error at regexp compilation time;
791 previously, the error went undetected, and results were
792 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
793 pattern.subn() methods have been rewritten in C. Also, an
794 experimental function/method finditer() has been added, which works
795 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000796
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000797- Tix exposes more commands through the classes DirSelectBox,
798 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
799 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
800 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
801
Tim Peters98791af2001-10-23 01:59:54 +0000802- Traceback objects are now scanned by cyclic garbage collection, so
803 cycles created by casual use of sys.exc_info() no longer cause
804 permanent memory leaks (provided garbage collection is enabled).
805
Guido van Rossum49192142001-10-24 20:51:44 +0000806- os.extsep -- a new variable needed by the RISCOS support. It is the
807 separator used by extensions, and is '.' on all platforms except
808 RISCOS, where it is '/'. There is no need to use this variable
809 unless you have a masochistic desire to port your code to RISCOS.
810
Barry Warsaw012852b2001-11-16 16:17:27 +0000811- mimetypes.py has optional support for non-standard, but commonly
812 found types. guess_type() and guess_extension() now accept an
813 optional `strict' flag, defaulting to true, which controls whether
814 recognize non-standard types or not. A few non-standard types we
815 know about have been added. Also, when run as a script, there are
816 new -l and -e options.
817
818- statcache is now deprecated.
819
820- email.Utils.formatdate() now produces the preferred RFC 2822 style
821 dates with numeric timezones (it used to produce obsolete dates
822 hard coded to "GMT" timezone). An optional `localtime' flag is
823 added to produce dates in the local timezone, with daylight savings
824 time properly taken into account.
825
826- In pickle and cPickle, instead of masking errors in load() by
827 transforming them into SystemError, we let the original exception
828 propagate out. Also, implement support for __safe_for_unpickling__
829 in pickle, as it already was supported in cPickle.
830
Tim Peters84362bc2001-10-19 17:55:30 +0000831Tools/Demos
832
833Build
834
Barry Warsaw012852b2001-11-16 16:17:27 +0000835- The dbm module is built using libdb1 if available. The bsddb module
836 is built with libdb3 if available.
837
838- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
839
Tim Peters84362bc2001-10-19 17:55:30 +0000840C API
841
Tim Peters1fc240e2001-10-26 05:06:50 +0000842- New function PySequence_Fast_GET_SIZE() returns the size of a non-
843 NULL result from PySequence_Fast(), more quickly than calling
844 PySequence_Size().
845
Barry Warsaw012852b2001-11-16 16:17:27 +0000846- New argument unpacking function PyArg_UnpackTuple() added.
847
848- New functions PyObject_CallFunctionObjArgs() and
849 PyObject_CallMethodObjArgs() have been added to make it more
850 convenient and efficient to call functions and methods from C.
851
852- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
853 possible that this will propagate errors it didn't before.
854
855- New function PyObject_CheckReadBuffer(), which returns true if its
856 argument supports the single-segment readable buffer interface.
857
Tim Peters84362bc2001-10-19 17:55:30 +0000858New platforms
859
Guido van Rossum86443212001-10-27 22:28:54 +0000860- We've finally confirmed that this release builds on HP-UX 11.00,
861 *with* threads, and passes the test suite.
862
Tim Peters7a33d8b2001-11-05 02:51:07 +0000863- Thanks to a series of patches from Michael Muller, Python may build
864 again under OS/2 Visual Age C++.
865
Guido van Rossum49192142001-10-24 20:51:44 +0000866- Updated RISCOS port by Dietmar Schwertberger.
867
Tim Peters84362bc2001-10-19 17:55:30 +0000868Tests
869
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000870- Added a test script for the curses module. It isn't run automatically;
871 regrtest.py must be run with '-u curses' to enable it.
872
Tim Peters84362bc2001-10-19 17:55:30 +0000873Windows
874
Barry Warsaw012852b2001-11-16 16:17:27 +0000875Mac
876
877- PythonScript has been moved to unsupported and is slated to be
878 removed completely in the next release.
879
880- It should now be possible to build applets that work on both OS9 and
881 OSX.
882
883- The core is now linked with CoreServices not Carbon; as a side
884 result, default 8bit encoding on OSX is now ASCII.
885
886- Python should now build on OSX 10.1.1
887
Tim Peters84362bc2001-10-19 17:55:30 +0000888
Tim Petersabf925f2001-09-28 21:53:42 +0000889What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000890Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000891===========================
892
893Type/class unification and new-style classes
894
Guido van Rossum687ae002001-10-15 22:03:32 +0000895- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000896 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000897 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000898 remains: the __dict__ of a new-style class is a read-only proxy; you
899 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000900 __defined__ attribute of new-style types no longer exists, for lack
901 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000902 future a __cache__ may be resurrected with a similar function, if I
903 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000904
Tim Peters1c9ca872001-10-04 06:43:12 +0000905- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
906 always returned None, even when there was a class docstring).
907
908- doctest now finds and runs docstrings attached to new-style classes,
909 class methods, static methods, and properties.
910
Guido van Rossum9074ef62001-10-16 21:34:49 +0000911Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000912
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000913- A very subtle syntactical pitfall in list comprehensions was fixed.
914 For example: [a+b for a in 'abc', for b in 'def']. The comma in
915 this example is a mistake. Previously, this would silently let 'a'
916 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
917 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
918 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
919 Note that [a for a in <singleton>] is a convoluted way to say
920 [<singleton>] anyway, so it's not like any expressiveness is lost.
921
Guido van Rossum9074ef62001-10-16 21:34:49 +0000922- getattr(obj, name, default) now only catches AttributeError, as
923 documented, rather than returning the default value for all
924 exceptions (which could mask bugs in a __getattr__ hook, for
925 example).
926
Fred Drakecb7a6b52001-10-22 18:41:51 +0000927- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000928 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000929 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000930 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000931
Guido van Rossum1c486092001-10-19 02:05:35 +0000932- unicode(obj) now behaves more like str(obj), accepting arbitrary
933 objects, and calling a __unicode__ method if it exists.
934 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000935 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000936
Barry Warsawf6fb1712001-10-19 05:35:40 +0000937- isinstance() now allows any object as the first argument and a
938 class, a type or something with a __bases__ tuple attribute for the
939 second argument. The second argument may also be a tuple of a
940 class, type, or something with __bases__, in which case isinstance()
941 will return true if the first argument is an instance of any of the
942 things contained in the second argument tuple. E.g.
943
944 isinstance(x, (A, B))
945
946 returns true if x is an instance of A or B.
947
Guido van Rossum9074ef62001-10-16 21:34:49 +0000948Extension modules
949
950- thread.start_new_thread() now returns the thread ID (previously None).
951
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000952- binascii has now two quopri support functions, a2b_qp and b2a_qp.
953
Guido van Rossumc524d952001-10-19 01:31:59 +0000954- readline now supports setting the startup_hook and the
955 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000956
Guido van Rossumc524d952001-10-19 01:31:59 +0000957- os and posix supports chroot(), setgroups() and unsetenv() where
958 available. The stat(), fstat(), statvfs() and fstatvfs() functions
959 now return "pseudo-sequences" -- the various fields can now be
960 accessed as attributes (e.g. os.stat("/").st_mtime) but for
961 backwards compatibility they also behave as a fixed-length sequence.
962 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000963 attributes.
964
965- time: localtime(), gmtime() and strptime() now return a
966 pseudo-sequence similar to the os.stat() return value, with
967 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000968
Guido van Rossum9074ef62001-10-16 21:34:49 +0000969- Decompression objects in the zlib module now accept an optional
970 second parameter to decompress() that specifies the maximum amount
971 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000972
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000973- optional SSL support in the socket module now exports OpenSSL
974 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
975 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000976 automatically seed its PRNG. Also, the keyfile and certfile
977 arguments to socket.ssl() are now optional.
978
979- posixmodule (and by extension, the os module on POSIX platforms) now
980 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000981
Guido van Rossum9074ef62001-10-16 21:34:49 +0000982Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000983
Tim Peters7402f792001-10-02 03:53:41 +0000984- doctest now excludes functions and classes not defined by the module
985 being tested, thanks to Tim Hochberg.
986
Fred Drakecb7a6b52001-10-22 18:41:51 +0000987- HotShot, a new profiler implemented using a C-based callback, has
988 been added. This substantially reduces the overhead of profiling,
989 but it is still quite preliminary. Support modules and
990 documentation will be added in upcoming releases (before 2.2 final).
991
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000992- profile now produces correct output in situations where an exception
993 raised in Python is cleared by C code (e.g. hasattr()). This used
994 to cause wrong output, including spurious claims of recursive
995 functions and attribution of time spent to the wrong function.
996
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000997 The code and documentation for the derived OldProfile and HotProfile
998 profiling classes was removed. The code hasn't worked for years (if
999 you tried to use them, they raised exceptions). OldProfile
1000 intended to reproduce the behavior of the profiler Python used more
1001 than 7 years ago, and isn't interesting anymore. HotProfile intended
1002 to provide a faster profiler (but producing less information), and
1003 that's a worthy goal we intend to meet via a different approach (but
1004 without losing information).
1005
Tim Peterscce092d2001-10-09 05:31:56 +00001006- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001007 a much better system-specific calibration constant. The constant can
1008 now be specified in an instance constructor, or as a Profile class or
1009 instance variable, instead of by editing profile.py's source code.
1010 Calibration must still be done manually (see the docs for the profile
1011 module).
1012
1013 Note that Profile.calibrate() must be overriden by subclasses.
1014 Improving the accuracy required exploiting detailed knowledge of
1015 profiler internals; the earlier method abstracted away the details
1016 and measured a simplified model instead, but consequently computed
1017 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001018
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001019- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001020 which indicates whether output is intended for the header 'Q'
1021 encoding.
1022
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001023- The SocketServer.ThreadingMixIn class now closes the request after
1024 finish_request() returns. (Not when it errors out though.)
1025
Barry Warsawf6fb1712001-10-19 05:35:40 +00001026- The nntplib module's NNTP.body() method has grown a `file' argument
1027 to allow saving the message body to a file.
1028
1029- The email package has added a class email.Parser.HeaderParser which
1030 only parses headers and does not recurse into the message's body.
1031 Also, the module/class MIMEAudio has been added for representing
1032 audio data (contributed by Anthony Baxter).
1033
1034- ftplib should be able to handle files > 2GB.
1035
1036- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1037 ON, and OFF.
1038
Fred Drakecb7a6b52001-10-22 18:41:51 +00001039- xml.dom.minidom NodeList objects now support the length attribute
1040 and item() method as required by the DOM specifications.
1041
Guido van Rossumed554f62001-10-02 23:15:37 +00001042Tools/Demos
1043
1044- Demo/dns was removed. It no longer serves any purpose; a package
1045 derived from it is now maintained by Anthony Baxter, see
1046 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001047
Barry Warsawf6fb1712001-10-19 05:35:40 +00001048- The freeze tool has been made more robust, and two new options have
1049 been added: -X and -E.
1050
Tim Petersabf925f2001-09-28 21:53:42 +00001051Build
1052
Barry Warsawf6fb1712001-10-19 05:35:40 +00001053- configure will use CXX in LINKCC if CXX is used to build main() and
1054 the system requires to link a C++ main using the C++ compiler.
1055
Tim Petersabf925f2001-09-28 21:53:42 +00001056C API
1057
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001058- The documentation for the tp_compare slot is updated to require that
1059 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1060 not correct. This is not yet enforced but will be enforced in
1061 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1062 "NotImplemented". Right now, -1 should be used for an error return.
1063
Tim Petersd38b1c72001-09-30 05:09:37 +00001064- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1065 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1066 as long) arguments.
1067
Guido van Rossum3c288632001-10-16 21:13:49 +00001068- PyThread_start_new_thread() now returns a long int giving the thread
1069 ID, if one can be calculated; it returns -1 for error, 0 if no
1070 thread ID is calculated (this is an incompatible change, but only
1071 the thread module used this API). This code has only really been
1072 tested on Linux and Windows; other platforms please beware (and
1073 report any bugs or strange behavior).
1074
Guido van Rossum1c486092001-10-19 02:05:35 +00001075- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1076 input.
1077
Tim Petersabf925f2001-09-28 21:53:42 +00001078New platforms
1079
1080Tests
1081
1082Windows
1083
Tim Peters04cf1d32001-10-09 22:39:40 +00001084- Installer: If you install IDLE, and don't disable file-extension
1085 registration, a new "Edit with IDLE" context (right-click) menu entry
1086 is created for .py and .pyw files.
1087
Tim Peters1ce3cf72001-10-01 17:58:40 +00001088- The signal module now supports SIGBREAK on Windows, thanks to Steven
1089 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1090 action remains to call Win32 ExitProcess(). This can be changed via
1091 signal.signal(). For example:
1092
1093 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1094 # (SIGINT) behavior.
1095 import signal
1096 signal.signal(signal.SIGBREAK,
1097 signal.default_int_handler)
1098
1099 try:
1100 while 1:
1101 pass
1102 except KeyboardInterrupt:
1103 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1104 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1105 # program without the possibility for any Python-level cleanup).
1106 print "Clean exit"
1107
Tim Petersabf925f2001-09-28 21:53:42 +00001108
Tim Petersb07352e2001-09-08 01:25:47 +00001109What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001110Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001111===========================
1112
Guido van Rossum808eea72001-09-25 04:15:41 +00001113Type/class unification and new-style classes
1114
1115- pydoc and inspect are now aware of new-style classes;
1116 e.g. help(list) at the interactive prompt now shows proper
1117 documentation for all operations on list objects.
1118
1119- Applications using Jim Fulton's ExtensionClass module can now safely
1120 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1121 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1122 examples also work again. It is hoped that Gtk and Boost also work
1123 with 2.2a4 and beyond. (If you can confirm this, please write
1124 webmaster@python.org; if there are still problems, please open a bug
1125 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001126
Tim Peters66c1a522001-09-24 21:17:50 +00001127- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001128 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001129 in the constructed property object. fget, fset and fdel weren't
1130 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1131 associate a docstring with a property.
1132
Guido van Rossum808eea72001-09-25 04:15:41 +00001133- Comparison overloading is now more completely implemented. For
1134 example, a str subclass instance can properly be compared to a str
1135 instance, and it can properly overload comparison. Ditto for most
1136 other built-in object types.
1137
1138- The repr() of new-style classes has changed; instead of <type
1139 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1140 *except* for built-in types, which are still rendered as <type
1141 'Foo'> (to avoid upsetting existing code that might parse or
1142 otherwise rely on repr() of certain type objects).
1143
1144- The repr() of new-style objects is now always <Foo object at XXX>;
1145 previously, it was sometimes <Foo instance at XXX>.
1146
1147- For new-style classes, what was previously called __getattr__ is now
1148 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001149 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001150 one in classic classes is defined which is called only if regular
1151 attribute access raises AttributeError; to catch *all* attribute
1152 access, you can use __getattribute__ (for new-style classes). If
1153 both are defined, __getattribute__ is called first, and if it raises
1154 AttributeError, __getattr__ is called.
1155
1156- The __class__ attribute of new-style objects can be assigned to.
1157 The new class must have the same C-level object layout as the old
1158 class.
1159
1160- The builtin file type can be subclassed now. In the usual pattern,
1161 "file" is the name of the builtin type, and file() is a new builtin
1162 constructor, with the same signature as the builtin open() function.
1163 file() is now the preferred way to open a file.
1164
1165- Previously, __new__ would only see sequential arguments passed to
1166 the type in a constructor call; __init__ would see both sequential
1167 and keyword arguments. This made no sense whatsoever any more, so
1168 now both __new__ and __init__ see all arguments.
1169
1170- Previously, hash() applied to an instance of a subclass of str or
1171 unicode always returned 0. This has been repaired.
1172
1173- Previously, an operation on an instance of a subclass of an
1174 immutable type (int, long, float, complex, tuple, str, unicode),
1175 where the subtype didn't override the operation (and so the
1176 operation was handled by the builtin type), could return that
1177 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001178 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001179 with the same value as s.
1180
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001181- Provisional support for pickling new-style objects has been added.
1182
Guido van Rossum808eea72001-09-25 04:15:41 +00001183Core
1184
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001185- file.writelines() now accepts any iterable object producing strings.
1186
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001187- PyUnicode_FromEncodedObject() now works very much like
1188 PyObject_Str(obj) in that it tries to use __str__/tp_str
1189 on the object if the object is not a string or buffer. This
1190 makes unicode() behave like str() when applied to non-string/buffer
1191 objects.
1192
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001193- PyFile_WriteObject now passes Unicode objects to the file's write
1194 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001195 of a print statement must support Unicode objects, i.e. they must
1196 at least convert them into ASCII strings.
1197
Guido van Rossum624c8af2001-09-18 15:21:04 +00001198- Thread scheduling on Solaris should be improved; it is no longer
1199 necessary to insert a small sleep at the start of a thread in order
1200 to let other runnable threads be scheduled.
1201
Tim Petersb07352e2001-09-08 01:25:47 +00001202Library
1203
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001204- StringIO.StringIO instances and cStringIO.StringIO instances support
1205 read character buffer compatible objects for their .write() methods.
1206 These objects are converted to strings and then handled as such
1207 by the instances.
1208
Barry Warsaw2f600732001-09-24 04:28:10 +00001209- The "email" package has been added. This is basically a port of the
1210 mimelib package <http://sf.net/projects/mimelib> with API changes
1211 and some implementations updated to use iterators and generators.
1212
Tim Peters8a9c2842001-09-22 21:30:22 +00001213- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1214 restores the ability of Tools/scripts/ndiff.py to start producing output
1215 before the entire comparison is complete.
1216
Barry Warsaw58b072d2001-09-22 04:44:21 +00001217- StringIO.StringIO instances and cStringIO.StringIO instances support
1218 iteration just like file objects (i.e. their .readline() method is
1219 called for each iteration until it returns an empty string).
1220
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001221- The codecs module has grown four new helper APIs to access
1222 builtin codecs: getencoder(), getdecoder(), getreader(),
1223 getwriter().
1224
Guido van Rossum624c8af2001-09-18 15:21:04 +00001225- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1226 simplifies writing XML RPC servers.
1227
Barry Warsaw647d5e82001-09-28 17:01:02 +00001228- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001229 after interpretation of symbolic links. On non-Unix systems, this
1230 is an alias for os.path.abspath().
1231
Tim Peters16a77ad2001-09-08 04:00:12 +00001232- operator.indexOf() (PySequence_Index() in the C API) now works with any
1233 iterable object.
1234
Guido van Rossum624c8af2001-09-18 15:21:04 +00001235- smtplib now supports various authentication and security features of
1236 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001237
Guido van Rossum624c8af2001-09-18 15:21:04 +00001238- hmac: a new module implementing keyed hashing for message
1239 authentication.
1240
1241- mimetypes now recognizes more extensions and file types. At the
1242 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001243
Guido van Rossum624c8af2001-09-18 15:21:04 +00001244- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001245 Python 2.2 bytecode generation. It has also been promoted from a
1246 Tool to a standard library package. (Tools/compiler still exists as
1247 a sample driver.)
1248
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001249Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001250
Tim Petersb07352e2001-09-08 01:25:47 +00001251Build
1252
Guido van Rossum624c8af2001-09-18 15:21:04 +00001253- Large file support (LFS) is now automatic when the platform supports
1254 it; no more manual configuration tweaks are needed. On Linux, at
1255 least, it's possible to have a system whose C library supports large
1256 files but whose kernel doesn't; in this case, large file support is
1257 still enabled but doesn't do you any good unless you upgrade your
1258 kernel or share your Python executable with another system whose
1259 kernel has large file support.
1260
1261- The configure script now supplies plausible defaults in a
1262 cross-compilation environment. This doesn't mean that the supplied
1263 values are always correct, or that cross-compilation now works
1264 flawlessly -- but it's a first step (and it shuts up most of
1265 autoconf's warnings about AC_TRY_RUN).
1266
1267- The Unix build is now a bit less chatty, courtesy of the parser
1268 generator. The build is completely silent (except for errors) when
1269 using "make -s", thanks to a -q option to setup.py.
1270
Tim Petersb07352e2001-09-08 01:25:47 +00001271C API
1272
Guido van Rossum624c8af2001-09-18 15:21:04 +00001273- The "structmember" API now supports some new flag bits to deny read
1274 and/or write access to attributes in restricted execution mode.
1275
Tim Petersb07352e2001-09-08 01:25:47 +00001276New platforms
1277
Guido van Rossum624c8af2001-09-18 15:21:04 +00001278- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1279 (http://familiar.handhelds.org).
1280
Tim Petersb07352e2001-09-08 01:25:47 +00001281Tests
1282
Tim Peters8a9c2842001-09-22 21:30:22 +00001283- The "classic" standard tests, which work by comparing stdout to
1284 an expected-output file under Lib/test/output/, no longer stop at
1285 the first mismatch. Instead the test is run to completion, and a
1286 variant of ndiff-style comparison is used to report all differences.
1287 This is much easier to understand than the previous style of reporting.
1288
1289- The unittest-based standard tests now use regrtest's test_main()
1290 convention, instead of running as a side-effect of merely being
1291 imported. This allows these tests to be run in more natural and
1292 flexible ways as unittests, outside the regrtest framework.
1293
1294- regrtest.py is much better integrated with unittest and doctest now,
1295 especially in regard to reporting errors.
1296
Tim Petersb07352e2001-09-08 01:25:47 +00001297Windows
1298
Guido van Rossum624c8af2001-09-18 15:21:04 +00001299- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001300 that support it (NTFS under Windows 2000). See "What's New in
1301 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001302
Tim Petersb07352e2001-09-08 01:25:47 +00001303
Tim Petersedc99312001-08-22 21:36:50 +00001304What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001305Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001306===========================
1307
1308Core
1309
Tim Peters9fffa3e2001-09-04 05:14:19 +00001310- Conversion of long to float now raises OverflowError if the long is too
1311 big to represent as a C double.
1312
Tim Peters32f453e2001-09-03 08:35:41 +00001313- The 3-argument builtin pow() no longer allows a third non-None argument
1314 if either of the first two arguments is a float, or if both are of
1315 integer types and the second argument is negative (in which latter case
1316 the arguments are converted to float, so this is really the same
1317 restriction).
1318
Tim Peters5d2b77c2001-09-03 05:47:38 +00001319- The builtin dir() now returns more information, and sometimes much
1320 more, generally naming all attributes of an object, and all attributes
1321 reachable from the object via its class, and from its class's base
1322 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1323 an empty list. In 2.2a3,
1324
1325 >>> dir([])
1326 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1327 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1328 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1329 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1330 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1331 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1332 'reverse', 'sort']
1333
1334 dir(module) continues to return only the module's attributes, though.
1335
Tim Petersbdee63f2001-09-02 03:40:59 +00001336- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001337 than raising OverflowError. This is a partial implementation of PEP
1338 237. You can use -Wdefault::OverflowWarning to enable a warning for
1339 this situation, and -Werror::OverflowWarning to revert to the old
1340 OverflowError exception.
1341
Guido van Rossum61c345f2001-09-04 03:26:15 +00001342- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001343 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001344 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1345 -Qold, meaning the / operator has its classic meaning and no
1346 warnings are issued. Using -Qwarn issues a run-time warning about
1347 all uses of classic division for int and long arguments; -Qwarnall
1348 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001349 (for use with fixdiv.py).
1350 [Note: the remainder of this paragraph (preserved below) became
1351 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1352 <obsolete>
1353 Using -Qnew is questionable; it turns on new division by default, but
1354 only in the __main__ module. You can usefully combine -Qwarn or
1355 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1356 warns about classic division everywhere else.
1357 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001358
Tim Petersbdee63f2001-09-02 03:40:59 +00001359- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001360 long, float, str, unicode, and tuple. (The types complex, list and
1361 dictionary can also be subclassed; this was introduced earlier.)
1362 Note that restrictions apply when subclassing immutable built-in
1363 types: you can only affect the value of the instance by overloading
1364 __new__. You can add mutable attributes, and the subclass instances
1365 will have a __dict__ attribute, but you cannot change the "value"
1366 (as implemented by the base class) of an immutable subclass instance
1367 once it is created.
1368
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001369- The dictionary constructor now takes an optional argument, a
1370 mapping-like object, and initializes the dictionary from its
1371 (key, value) pairs.
1372
Tim Petersbdee63f2001-09-02 03:40:59 +00001373- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001374 "cooperative super calls" in a multiple inheritance setting. For an
1375 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1376
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001377- A new built-in type, property, has been added. This enables the
1378 creation of "properties". These are attributes implemented by
1379 getter and setter functions (or only one of these for read-only or
1380 write-only attributes), without the need to override __getattr__.
1381 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001382
Tim Petersbdee63f2001-09-02 03:40:59 +00001383- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001384 liberalized, to allow leading zeroes. Examples of literals now
1385 legal that were SyntaxErrors before:
1386
1387 00.0 0e3 0100j 07.5 00000000000000000008.
1388
Tim Petersbdee63f2001-09-02 03:40:59 +00001389- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001390 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1391
Tim Petersedc99312001-08-22 21:36:50 +00001392Library
1393
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001394- telnetlib includes symbolic names for the options, and support for
1395 setting an option negotiation callback.
1396
Tim Petersa40c7932001-09-05 22:36:56 +00001397- The new C standard no longer requires that math libraries set errno to
1398 ERANGE on overflow. For platform libraries that exploit this new
1399 freedom, Python's overflow-checking was wholly broken. A new overflow-
1400 checking scheme attempts to repair that, but may not be reliable on all
1401 platforms (C doesn't seem to provide anything both useful and portable
1402 in this area anymore).
1403
Martin v. Löwis44f86962001-09-05 13:44:54 +00001404- Asynchronous timeout actions are available through the new class
1405 threading.Timer.
1406
Tim Peters78526162001-09-05 00:53:45 +00001407- math.log and math.log10 now return sensible results for even huge
1408 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1409
Tim Petersbdee63f2001-09-02 03:40:59 +00001410- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001411 currently held. See the docs for the imp module.
1412
Tim Petersbdee63f2001-09-02 03:40:59 +00001413- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001414 dumps containing ints written on platforms where Python ints are 8 bytes.
1415 When read on a box where Python ints are 4 bytes, such values are
1416 converted to Python longs.
1417
Tim Petersbdee63f2001-09-02 03:40:59 +00001418- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001419 code objects is no longer allowed. This plugs a security hole.
1420
Steve Purcell6091cd62001-09-06 16:05:17 +00001421- unittest.TestResult instances no longer store references to tracebacks
1422 generated by test failures. This prevents unexpected dangling references
1423 to objects that should be garbage collected between tests.
1424
Tim Petersedc99312001-08-22 21:36:50 +00001425Tools
1426
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001427- Tools/scripts/fixdiv.py has been added which can be used to fix
1428 division operators as per PEP 238.
1429
Tim Petersedc99312001-08-22 21:36:50 +00001430Build
1431
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001432- If you are an adventurous person using Mac OS X you may want to look at
1433 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1434 application, which can be used for experimenting with Carbon or Cocoa.
1435 Discussion of this on pythonmac-sig, please.
1436
Tim Peters7eea37e2001-09-04 22:08:56 +00001437C API
1438
1439- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001440
Tim Peters9fffa3e2001-09-04 05:14:19 +00001441- Note that PyLong_AsDouble can fail! This has always been true, but no
1442 callers checked for it. It's more likely to fail now, because overflow
1443 errors are properly detected now. The proper way to check:
1444
1445 double x = PyLong_AsDouble(some_long_object);
1446 if (x == -1.0 && PyErr_Occurred()) {
1447 /* The conversion failed. */
1448 }
1449
Tim Petersbdee63f2001-09-02 03:40:59 +00001450- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001451 compile but will not participate in GC. To upgrade an extension
1452 module:
1453
1454 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001455
Neil Schemenauer4042c692001-08-30 15:38:01 +00001456 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1457 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001458
Neil Schemenauer4042c692001-08-30 15:38:01 +00001459 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1460 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001461
Neil Schemenauer4042c692001-08-30 15:38:01 +00001462 - remove PyGC_HEAD_SIZE from object size calculations
1463
1464 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1465
Tim Petersbdee63f2001-09-02 03:40:59 +00001466- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001467 These can be used safely to construct string objects from a
1468 sprintf-style format string (similar to the format string supported
1469 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001470
Tim Petersedc99312001-08-22 21:36:50 +00001471New platforms
1472
Tim Petersb7da0902001-09-02 23:01:43 +00001473- Stephen Hansen contributed patches sufficient to get a clean compile
1474 under Borland C (Windows), but he reports problems running it and ran
1475 out of time to complete the port. Volunteers? Expect a MemoryError
1476 when importing the types module; this is probably shallow, and
1477 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001478
Tim Petersedc99312001-08-22 21:36:50 +00001479Tests
1480
1481Windows
1482
Tim Peters6e13a562001-09-06 00:32:15 +00001483- Large file support is now enabled on Win32 platforms as well as on
1484 Win64. This means that, for example, you can use f.tell() and f.seek()
1485 to manipulate files larger than 2 gigabytes (provided you have enough
1486 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001487 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1488 filesize limit, and large file support makes no difference there.
1489 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1490 NTFS has no practical limit on file size, and files of any size can be
1491 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001492
Tim Petersbdee63f2001-09-02 03:40:59 +00001493- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001494 points to command.com (patch from Brian Quinlan).
1495
Tim Petersedc99312001-08-22 21:36:50 +00001496
Tim Peters20f51a72001-07-21 02:31:40 +00001497What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001498Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001499===========================
1500
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001501Build
1502
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001503- Tim Peters developed a brand new Windows installer using Wise 8.1,
1504 generously donated to us by Wise Solutions.
1505
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001506- configure supports a new option --enable-unicode, with the values
1507 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1508 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001509
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001510- A new configure option --enable-framework builds a Mac OS X framework,
1511 which "make frameworkinstall" will install. This provides a starting
1512 point for more mac-like functionality, join pythonmac-sig@python.org
1513 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001514
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001515- The NeXT platform is no longer supported.
1516
1517- The `new' module is now statically linked.
1518
Tim Peters0afb6092001-08-15 06:06:44 +00001519Tools
1520
1521- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001522 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001523 the module docstring for details.
1524
Tim Peters20f51a72001-07-21 02:31:40 +00001525Tests
1526
Tim Peters5e824c32001-08-12 22:25:01 +00001527- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001528 platforms, allowing to give clearer test result output. regrtest
1529 also has optional --use/-u switch to run normally disabled tests
1530 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001531
Tim Peters20f51a72001-07-21 02:31:40 +00001532- Several new tests in the standard test suite, with special thanks to
1533 Nick Mathewson.
1534
1535Core
1536
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001537- The floor division operator // has been added as outlined in PEP
1538 238. The / operator still provides classic division (and will until
1539 Python 3.0) unless "from __future__ import division" is included, in
1540 which case the / operator will provide true division. The operator
1541 module provides truediv() and floordiv() functions. Augmented
1542 assignment variants are included, as are the equivalent overloadable
1543 methods and C API methods. See the PEP for a full discussion:
1544 <http://python.sf.net/peps/pep-0238.html>
1545
Tim Peters6cd6a822001-08-17 22:11:27 +00001546- Future statements are now effective in simulated interactive shells
1547 (like IDLE). This should "just work" by magic, but read Michael
1548 Hudson's "Future statements in simulated shells" PEP 264 for full
1549 details: <http://python.sf.net/peps/pep-0264.html>.
1550
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001551- The type/class unification (PEP 252-253) was integrated into the
1552 trunk and is not so tentative any more (the exact specification of
1553 some features is still tentative). A lot of work has done on fixing
1554 bugs and adding robustness and features (performance still has to
1555 come a long way).
1556
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001557- Warnings about a mismatch in the Python API during extension import
1558 now use the Python warning framework (which makes it possible to
1559 write filters for these warnings).
1560
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001561- A function's __dict__ (aka func_dict) will now always be a
1562 dictionary. It used to be possible to delete it or set it to None,
1563 but now both actions raise TypeErrors. It is still legal to set it
1564 to a dictionary object. Getting func.__dict__ before any attributes
1565 have been assigned now returns an empty dictionary instead of None.
1566
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001567- A new command line option, -E, was added which disables the use of
1568 all environment variables, or at least those that are specifically
1569 significant to Python. Usually those have a name starting with
1570 "PYTHON". This was used to fix a problem where the tests fail if
1571 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1572 older distribution.
1573
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001574Library
1575
Tim Peters5e824c32001-08-12 22:25:01 +00001576- New class Differ and new functions ndiff() and restore() in difflib.py.
1577 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001578 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001579
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001580- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1581 value using the minimal quoting required for the value; more
1582 reliable than using xml.sax.saxutils.escape() for attribute values.
1583
1584- Readline completion support for cmd.Cmd was added.
1585
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001586- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1587
1588- Added function threading.BoundedSemaphore()
1589
1590- Added Ka-Ping Yee's cgitb.py module.
1591
1592- The `new' module now exposes the CO_xxx flags.
1593
Martin v. Löwis560da622001-11-24 09:24:51 +00001594- The gc module offers the get_referents function.
1595
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001596New platforms
1597
1598C API
1599
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001600- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1601 which provide a cross-platform implementations for the
1602 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1603 the standard sprintf() and vsprintf() C lib APIs, these versions
1604 apply bounds checking on the used buffer which enhances protection
1605 against buffer overruns.
1606
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001607- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001608 and extensions using different Unicode widths is rendered next to
1609 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001610 will result in an ImportError. Unicode extensions writers must make
1611 sure to check the Unicode width compatibility in their extensions by
1612 using at least one of the mangled Unicode APIs in the extension.
1613
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001614- Two new flags METH_NOARGS and METH_O are available in method definition
1615 tables to simplify implementation of methods with no arguments and a
1616 single untyped argument. Calling such methods is more efficient than
1617 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1618 deprecated.
1619
Tim Petersc1731372001-08-04 08:12:36 +00001620Windows
1621
1622- "import module" now compiles module.pyw if it exists and nothing else
1623 relevant is found.
1624
Tim Peters20f51a72001-07-21 02:31:40 +00001625
Guido van Rossum55a78992001-07-17 17:22:32 +00001626What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001627Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001628===========================
1629
1630Core
Tim Petersa814db52001-05-14 07:05:58 +00001631
Tim Peters6d6c1a32001-08-02 04:15:00 +00001632- TENTATIVELY, a large amount of code implementing much of what's
1633 described in PEP 252 (Making Types Look More Like Classes) and PEP
1634 253 (Subtyping Built-in Types) was added. This will be released
1635 with Python 2.2a1. Documentation will be provided separately
1636 through http://www.python.org/2.2/. The purpose of releasing this
1637 with Python 2.2a1 is to test backwards compatibility. It is
1638 possible, though not likely, that a decision is made not to release
1639 this code as part of 2.2 final, if any serious backwards
1640 incompapatibilities are found during alpha testing that cannot be
1641 repaired.
1642
Guido van Rossum55a78992001-07-17 17:22:32 +00001643- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001644 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001645 more 'yield' statements. See PEP 255. Since this adds a new
1646 keyword to the language, this feature must be enabled by including a
1647 future statement: "from __future__ import generators" (see PEP 236).
1648 Generators will become a standard feature in a future release
1649 (probably 2.3). Without this future statement, 'yield' remains an
1650 ordinary identifier, but a warning is issued each time it is used.
1651 (These warnings currently don't conform to the warnings framework of
1652 PEP 230; we intend to fix this in 2.2a2.)
1653
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001654- The UTF-16 codec was modified to be more RFC compliant. It will now
1655 only remove BOM characters at the start of the string and then
1656 only if running in native mode (UTF-16-LE and -BE won't remove a
1657 leading BMO character).
1658
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001659- Strings now have a new method .decode() to complement the already
1660 existing .encode() method. These two methods provide direct access
1661 to the corresponding decoders and encoders of the registered codecs.
1662
1663 To enhance the usability of the .encode() method, the special
1664 casing of Unicode object return values was dropped (Unicode objects
1665 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001666
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001667 Both methods will now return whatever the codec in charge of the
1668 requested encoding returns as object, e.g. Unicode codecs will
1669 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1670 will return u"äöü"). This enables codec writer to create codecs
1671 for various simple to use conversions.
1672
1673 New codecs were added to demonstrate these new features (the .encode()
1674 and .decode() columns indicate the type of the returned objects):
1675
1676 Name | .encode() | .decode() | Description
1677 ----------------------------------------------------------------------
1678 uu | string | string | UU codec (e.g. for email)
1679 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001680 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001681 zlib | string | string | zlib compression
1682 hex | string | string | 2-byte hex codec
1683 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1684
Mark Hammond2a0af792001-05-14 03:09:36 +00001685- Some operating systems now support the concept of a default Unicode
1686 encoding for file system operations. Notably, Windows supports 'mbcs'
1687 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001688 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001689 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001690
1691 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001692 functions that return filenames (such as os.listdir()) to return Python
1693 string objects pre-encoded using the default file system encoding for
1694 the platform. As this encoding is likely to be different from Python's
1695 default encoding, converting this name to a Unicode object before passing
1696 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001697 would attempt to use its default encoding (generally ASCII) rather than
1698 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001699
Tim Petersa814db52001-05-14 07:05:58 +00001700 In general, this change simply removes surprises when working with
1701 Unicode and the file system, making these operations work as you expect,
1702 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001703 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001704
Tim Peters61dff2b2001-05-08 15:43:37 +00001705- Float (and complex) literals in source code were evaluated to full
1706 precision only when running from a .py file; the same code loaded from a
1707 .pyc (or .pyo) file could suffer numeric differences starting at about the
1708 12th significant decimal digit. For example, on a machine with IEEE-754
1709 floating arithmetic,
1710
1711 x = 9007199254740992.0
1712 print long(x)
1713
1714 printed 9007199254740992 if run directly from .py, but 9007199254740000
1715 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1716 str(float) instead of repr(float) when building code objects. marshal
1717 now uses repr(float) instead, which should reproduce floats to full
1718 machine precision (assuming the platform C float<->string I/O conversion
1719 functions are of good quality).
1720
1721 This may cause floating-point results to change in some cases, and
1722 usually for the better, but may also cause numerically unstable
1723 algorithms to break.
1724
Tim Peters2f228e72001-05-13 00:19:31 +00001725- The implementation of dicts suffers fewer collisions, which has speed
1726 benefits. However, the order in which dict entries appear in dict.keys(),
1727 dict.values() and dict.items() may differ from previous releases for a
1728 given dict. Nothing is defined about this order, so no program should
1729 rely on it. Nevertheless, it's easy to write test cases that rely on the
1730 order by accident, typically because of printing the str() or repr() of a
1731 dict to an "expected results" file. See Lib/test/test_support.py's new
1732 sortdict(dict) function for a simple way to display a dict in sorted
1733 order.
1734
Tim Peters7a3bfc32001-06-12 01:22:22 +00001735- Many other small changes to dicts were made, resulting in faster
1736 operation along the most common code paths.
1737
Guido van Rossum10315822001-05-01 20:54:30 +00001738- Dictionary objects now support the "in" operator: "x in dict" means
1739 the same as dict.has_key(x).
1740
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001741- The update() method of dictionaries now accepts generic mapping
1742 objects. Specifically the argument object must support the .keys()
1743 and __getitem__() methods. This allows you to say, for example,
1744 {}.update(UserDict())
1745
Guido van Rossum10315822001-05-01 20:54:30 +00001746- Iterators were added; this is a generalized way of providing values
1747 to a for loop. See PEP 234. There's a new built-in function iter()
1748 to return an iterator. There's a new protocol to get the next value
1749 from an iterator using the next() method (in Python) or the
1750 tp_iternext slot (in C). There's a new protocol to get iterators
1751 using the __iter__() method (in Python) or the tp_iter slot (in C).
1752 Iterating (i.e. a for loop) over a dictionary generates its keys.
1753 Iterating over a file generates its lines.
1754
Tim Petersf553f892001-05-01 20:45:31 +00001755- The following functions were generalized to work nicely with iterator
1756 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001757 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001758 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1759 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001760 join() method of strings
1761 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001762 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1763 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001764 right-hand side of assignment statements with multiple targets, such as
1765 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001766
Tim Petersd85e1022001-05-11 21:51:48 +00001767- Accessing module attributes is significantly faster (for example,
1768 random.random or os.path or yourPythonModule.yourAttribute).
1769
Tim Peterse63415e2001-05-08 04:38:29 +00001770- Comparing dictionary objects via == and != is faster, and now works even
1771 if the keys and values don't support comparisons other than ==.
1772
Tim Peters95bf9392001-05-10 08:32:44 +00001773- Comparing dictionaries in ways other than == and != is slower: there were
1774 insecurities in the dict comparison implementation that could cause Python
1775 to crash if the element comparison routines for the dict keys and/or
1776 values mutated the dicts. Making the code bulletproof slowed it down.
1777
Tim Peterseb28ef22001-06-02 05:27:19 +00001778- Collisions in dicts are resolved via a new approach, which can help
1779 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001780 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001781 faster now. Thanks to Christian Tismer for pointing out the cause and
1782 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001783
Tim Peters52e155e2001-06-16 05:42:57 +00001784- repr() is much faster for large containers (dict, list, tuple).
1785
1786
Tim Petersa814db52001-05-14 07:05:58 +00001787Library
1788
Fred Drake960fdf92001-07-20 18:38:26 +00001789- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1790 were added to the string module. These a locale-indenpendent
1791 constants, unlike letters, lowercase, and uppercase. These are now
1792 use in appropriate locations in the standard library.
1793
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001794- The flags used in dlopen calls can now be configured using
1795 sys.setdlopenflags and queried using sys.getdlopenflags.
1796
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001797- Fredrik Lundh's xmlrpclib is now a standard library module. This
1798 provides full client-side XML-RPC support. In addition,
1799 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1800 one asyncore-based). Thanks to Eric Raymond for the documentation.
1801
Guido van Rossum643d3912001-07-05 14:46:25 +00001802- The xrange() object is simplified: it no longer supports slicing,
1803 repetition, comparisons, efficient 'in' checking, the tolist()
1804 method, or the start, stop and step attributes. See PEP 260.
1805
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001806- A new function fnmatch.filter to filter lists of file names was added.
1807
Barry Warsawffd674d2001-05-22 16:00:10 +00001808- calendar.py uses month and day names based on the current locale.
1809
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001810- strop is now *really* obsolete (this was announced before with 1.6),
1811 and issues DeprecationWarning when used (except for the four items
1812 that are still imported into string.py).
1813
Tim Petersa814db52001-05-14 07:05:58 +00001814- Cookie.py now sorts key+value pairs by key in output strings.
1815
1816- pprint.isrecursive(object) didn't correctly identify recursive objects.
1817 Now it does.
1818
Tim Peters95b3f782001-05-14 18:39:41 +00001819- pprint functions now much faster for large containers (tuple, list, dict).
1820
Tim Peters7b9542a2001-06-10 23:40:19 +00001821- New 'q' and 'Q' format codes in the struct module, corresponding to C
1822 types "long long" and "unsigned long long" (on Windows, __int64). In
1823 native mode, these can be used only when the platform C compiler supports
1824 these types (when HAVE_LONG_LONG is #define'd by the Python config
1825 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001826 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1827 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001828
Guido van Rossum83213cc2001-06-12 16:48:52 +00001829- The site module installs a new built-in function 'help' that invokes
1830 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1831 it displays a message reminding the user to use 'help()' or
1832 'help(object)'.
1833
Tim Petersa814db52001-05-14 07:05:58 +00001834Tests
1835
1836- New test_mutants.py runs dict comparisons where the key and value
1837 comparison operators mutute the dicts randomly during comparison. This
1838 rapidly causes Python to crash under earlier releases (not for the faint
1839 of heart: it can also cause Win9x to freeze or reboot!).
1840
1841- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001842 pprint.isreadable() return sensible results. Also verifies that simple
1843 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001844
Tim Peters4324aa32001-05-28 22:30:08 +00001845C API
1846
1847- Removed the unused last_is_sticky argument from the internal
1848 _PyTuple_Resize(). If this affects you, you were cheating.
1849
1850
Guido van Rossum55a78992001-07-17 17:22:32 +00001851======================================================================
1852
1853
Guido van Rossumffe13be2001-04-16 18:46:45 +00001854What's New in Python 2.1 (final)?
1855=================================
1856
1857We only changed a few things since the last release candidate, all in
1858Python library code:
1859
1860- A bug in the locale module was fixed that affected locales which
1861 define no grouping for numeric formatting.
1862
1863- A few bugs in the weakref module's implementations of weak
1864 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1865 and the test suite was updated to check for these bugs.
1866
1867- An old bug in the os.path.walk() function (introduced in Python
1868 2.0!) was fixed: a non-existent file would cause an exception
1869 instead of being ignored.
1870
1871- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1872 PyChecker.
1873
1874
Guido van Rossum5b08f132001-04-16 02:05:23 +00001875What's New in Python 2.1c2?
1876===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001877
Guido van Rossum5b08f132001-04-16 02:05:23 +00001878A flurry of small changes, and one showstopper fixed in the nick of
1879time made it necessary to release another release candidate. The list
1880here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001881
Guido van Rossum5b08f132001-04-16 02:05:23 +00001882Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001883
Guido van Rossum5b08f132001-04-16 02:05:23 +00001884- Tim discovered a nasty bug in the dictionary code, caused by
1885 PyDict_Next() calling dict_resize(), and the GC code's use of
1886 PyDict_Next() violating an assumption in dict_items(). This was
1887 fixed with considerable amounts of band-aid, but the net effect is a
1888 saner and more robust implementation.
1889
1890- Made a bunch of symbols static that were accidentally global.
1891
1892Build and Ports
1893
1894- The setup.py script didn't check for a new enough version of zlib
1895 (1.1.3 is needed). Now it does.
1896
1897- Changed "make clean" target to also remove shared libraries.
1898
1899- Added a more general warning about the SGI Irix optimizer to README.
1900
1901Library
1902
1903- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1904 omitted the slash between host and file.html.
1905
1906- The mailbox module's _Mailbox class contained a completely broken
1907 and undocumented seek() method. Ripped it out.
1908
1909- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1910 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1911
1912- Fixed a few last-minute bugs in unittest.
1913
1914Extensions
1915
1916- Reverted the patch to the OpenSSL code in socketmodule.c to support
1917 RAND_status() and the EGD, and the subsequent patch that tried to
1918 fix it for pre-0.9.5 versions; the problem with the patch is that on
1919 some systems it issues a warning whenever socket is imported, and
1920 that's unacceptable.
1921
1922Tests
1923
1924- Fixed the pickle tests to work with "import test.test_pickle".
1925
1926- Tweaked test_locale.py to actually run the test Windows.
1927
1928- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1929 not "wb" (which is not a valid mode at all).
1930
1931- Fix pstats browser crashes. Import readline if it exists to make
1932 the user interface nicer.
1933
1934- Add "import thread" to the top of test modules that import the
1935 threading module (test_asynchat and test_threadedtempfile). This
1936 prevents test failures caused by a broken threading module resulting
1937 from a previously caught failed import.
1938
1939- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1940 needed on some platforms (e.g. Solaris 8) when the tests are run
1941 twice in succession.
1942
1943- Skip rather than fail test_sunaudiodev if no audio device is found.
1944
1945
1946What's New in Python 2.1c1?
1947===========================
1948
1949This list was significantly updated when 2.1c2 was released; the 2.1c1
1950release didn't mention most changes that were actually part of 2.1c1:
1951
1952Legal
1953
1954- Copyright was assigned to the Python Software Foundation (PSF) and a
1955 PSF license (very similar to the CNRI license) was added.
1956
1957- The CNRI copyright notice was updated to include 2001.
1958
1959Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001960
Guido van Rossumc9932722001-04-12 02:31:27 +00001961- After a public outcry, assignment to __debug__ is no longer illegal;
1962 instead, a warning is issued. It will become illegal in 2.2.
1963
Guido van Rossum5b08f132001-04-16 02:05:23 +00001964- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1965 "%#x" now always prepends "0x", even if the value is zero.
1966
1967- Fixed some nits in the bytecode compiler.
1968
1969- Fixed core dumps when calling certain kinds of non-functions.
1970
1971- Fixed various core dumps caused by reference count bugs.
1972
1973Build and Ports
1974
1975- Use INSTALL_SCRIPT to install script files.
1976
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001977- New port: SCO Unixware 7, by Billy G. Allie.
1978
Guido van Rossum5b08f132001-04-16 02:05:23 +00001979- Updated RISCOS port.
1980
1981- Updated BeOS port and notes.
1982
1983- Various other porting problems resolved.
1984
1985Library
1986
1987- The TERMIOS and SOCKET modules are now truly obsolete and
1988 unnecessary. Their symbols are incorporated in the termios and
1989 socket modules.
1990
1991- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1992 better tests for pickling.
1993
1994- threading: make Condition.wait() robust against KeyboardInterrupt.
1995
1996- zipfile: add support to zipfile to support opening an archive
1997 represented by an open file rather than a file name. Fix bug where
1998 the archive was not properly closed. Fixed a bug in this bugfix
1999 where flush() was called for a read-only file.
2000
2001- imputil: added an uninstall() method to the ImportManager.
2002
2003- Canvas: fixed bugs in lower() and tkraise() methods.
2004
2005- SocketServer: API change (added overridable close_request() method)
2006 so that the TCP server can explicitly close the request.
2007
2008- pstats: Eric Raymond added a simple interactive statistics browser,
2009 invoked when the module is run as a script.
2010
2011- locale: fixed a problem in format().
2012
2013- webbrowser: made it work when the BROWSER environment variable has a
2014 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
2015 KDE 2. Fixed some other nits.
2016
2017- unittest: changes to allow using a different exception than
2018 AssertionError, and added a few more function aliases. Some other
2019 small changes.
2020
2021- urllib, urllib2: fixed redirect problems and a coupleof other nits.
2022
2023- asynchat: fixed a critical bug in asynchat that slipped through the
2024 2.1b2 release. Fixed another rare bug.
2025
2026- Fix some unqualified except: clauses (always a bad code example).
2027
2028XML
2029
2030- pyexpat: new API get_version_string().
2031
2032- Fixed some minidom bugs.
2033
2034Extensions
2035
2036- Fixed a core dump in _weakref. Removed the weakref.mapping()
2037 function (it adds nothing to the API).
2038
2039- Rationalized the use of header files in the readline module, to make
2040 it compile (albeit with some warnings) with the very recent readline
2041 4.2, without breaking for earlier versions.
2042
2043- Hopefully fixed a buffering problem in linuxaudiodev.
2044
2045- Attempted a fix to make the OpenSSL support in the socket module
2046 work again with pre-0.9.5 versions of OpenSSL.
2047
2048Tests
2049
2050- Added a test case for asynchat and asyncore.
2051
2052- Removed coupling between tests where one test failing could break
2053 another.
2054
2055Tools
2056
2057- Ping added an interactive help browser to pydoc, fixed some nits
2058 in the rest of the pydoc code, and added some features to his
2059 inspect module.
2060
2061- An updated python-mode.el version 4.1 which integrates Ken
2062 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2063 much nicer in XEmacs and Emacs. When stepping through your program
2064 with pdb, in either the shell window or the *Python* window, the
2065 source file and line will be tracked by an arrow. Very cool!
2066
2067- IDLE: syntax warnings in interactive mode are changed into errors.
2068
2069- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002070 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002071
2072- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002073
Barry Warsaw11e89c72001-04-11 20:37:57 +00002074
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002075What's New in Python 2.1 beta 2?
2076================================
2077
Guido van Rossum053ae352001-03-22 14:17:21 +00002078(Unlisted are many fixed bugs, more documentation, etc.)
2079
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002080Core language, builtins, and interpreter
2081
Guido van Rossum053ae352001-03-22 14:17:21 +00002082- The nested scopes work (enabled by "from __future__ import
2083 nested_scopes") is completed; in particular, the future now extends
2084 into code executed through exec, eval() and execfile(), and into the
2085 interactive interpreter.
2086
2087- When calling a base class method (e.g. BaseClass.__init__(self)),
2088 this is now allowed even if self is not strictly spoken a class
2089 instance (e.g. when using metaclasses or the Don Beaudry hook).
2090
2091- Slice objects are now comparable but not hashable; this prevents
2092 dict[:] from being accepted but meaningless.
2093
2094- Complex division is now calculated using less braindead algorithms.
2095 This doesn't change semantics except it's more likely to give useful
2096 results in extreme cases. Complex repr() now uses full precision
2097 like float repr().
2098
2099- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2100
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002101- It is illegal to assign to the name __debug__, which is set when the
2102 interpreter starts. It is effectively a compile-time constant.
2103
2104- A warning will be issued if a global statement for a variable
2105 follows a use or assignment of that variable.
2106
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002107Standard library
2108
Guido van Rossum053ae352001-03-22 14:17:21 +00002109- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2110 inspired by JUnit), is now part of the standard library. You now
2111 have a choice of two testing frameworks: unittest requires you to
2112 write testcases as separate code, doctest gathers them from
2113 docstrings. Both approaches have their advantages and
2114 disadvantages.
2115
2116- A new module Tix was added, which wraps the Tix extension library
2117 for Tk. With that module, it is not necessary to statically link
2118 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2119 require" command. See Demo/tix/.
2120
2121- tzparse.py is now obsolete.
2122
2123- In gzip.py, the seek() and tell() methods are removed -- they were
2124 non-functional anyway, and it's better if callers can test for their
2125 existence with hasattr().
2126
2127Python/C API
2128
2129- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2130 that's already in the dictionary during a PyDict_Next() iteration.
2131 This used to fail occasionally when a dictionary resize operation
2132 could be triggered that would rehash all the keys. All other
2133 modifications to the dictionary are still off-limits during a
2134 PyDict_Next() iteration!
2135
2136- New extended APIs related to passing compiler variables around.
2137
2138- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2139 implement isinstance() and issubclass().
2140
2141- Py_BuildValue() now has a "D" conversion to create a Python complex
2142 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002143
Fred Drake4e262a92001-03-22 18:26:47 +00002144- Extensions types which support weak references must now set the
2145 field allocated for the weak reference machinery to NULL themselves;
2146 this is done to avoid the cost of checking each object for having a
2147 weakly referencable type in PyObject_INIT(), since most types are
2148 not weakly referencable.
2149
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002150- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2151 free variables and cell variables to and from the frame's f_locals.
2152
2153- Variants of several functions defined in pythonrun.h have been added
2154 to support the nested_scopes future statement. The variants all end
2155 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2156 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2157 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002158 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002159
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002160Distutils
2161
2162- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2163 into the release tree.
2164
Tim Peters0e57abf2001-05-02 07:39:38 +00002165- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002166 (an uninstaller, more customization of the installer's display)
2167
2168- from Jack Jansen: added Mac-specific code to generate a dialog for
2169 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002170 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002171 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002172
2173- added 'platforms' and 'keywords' to the set of metadata that can be
2174 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002175
2176- applied patches from Jason Tishler to make the compiler class work with
2177 Cygwin.
2178
2179
Tim Peters2fe289a2001-03-01 22:19:38 +00002180What's New in Python 2.1 beta 1?
2181================================
Tim Petersd66595f2001-02-04 03:09:53 +00002182
2183Core language, builtins, and interpreter
2184
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002185- Following an outcry from the community about the amount of code
2186 broken by the nested scopes feature introduced in 2.1a2, we decided
2187 to make this feature optional, and to wait until Python 2.2 (or at
2188 least 6 months) to make it standard. The option can be enabled on a
2189 per-module basis by adding "from __future__ import nested_scopes" at
2190 the beginning of a module (before any other statements, but after
2191 comments and an optional docstring). See PEP 236 (Back to the
2192 __future__) for a description of the __future__ statement. PEP 227
2193 (Statically Nested Scopes) has been updated to reflect this change,
2194 and to clarify the semantics in a number of endcases.
2195
2196- The nested scopes code, when enabled, has been hardened, and most
2197 bugs and memory leaks in it have been fixed.
2198
2199- Compile-time warnings are now generated for a number of conditions
2200 that will break or change in meaning when nested scopes are enabled:
2201
2202 - Using "from...import *" or "exec" without in-clause in a function
2203 scope that also defines a lambda or nested function with one or
2204 more free (non-local) variables. The presence of the import* or
2205 bare exec makes it impossible for the compiler to determine the
2206 exact set of local variables in the outer scope, which makes it
2207 impossible to determine the bindings for free variables in the
2208 inner scope. To avoid the warning about import *, change it into
2209 an import of explicitly name object, or move the import* statement
2210 to the global scope; to avoid the warning about bare exec, use
2211 exec...in... (a good idea anyway -- there's a possibility that
2212 bare exec will be deprecated in the future).
2213
2214 - Use of a global variable in a nested scope with the same name as a
2215 local variable in a surrounding scope. This will change in
2216 meaning with nested scopes: the name in the inner scope will
2217 reference the variable in the outer scope rather than the global
2218 of the same name. To avoid the warning, either rename the outer
2219 variable, or use a global statement in the inner function.
2220
Neil Schemenauera35c6882001-02-27 04:45:05 +00002221- An optional object allocator has been included. This allocator is
2222 optimized for Python objects and should be faster and use less memory
2223 than the standard system allocator. It is not enabled by default
2224 because of possible thread safety problems. The allocator is only
2225 protected by the Python interpreter lock and it is possible that some
2226 extension modules require a thread safe allocator. The object
2227 allocator can be enabled by providing the "--with-pymalloc" option to
2228 configure.
2229
Tim Petersd66595f2001-02-04 03:09:53 +00002230Standard library
2231
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002232- pyexpat now detects the expat version if expat.h defines it. A
2233 number of additional handlers are provided, which are only available
2234 since expat 1.95. In addition, the methods SetParamEntityParsing and
2235 GetInputContext of Parser objects are available with 1.95.x
2236 only. Parser objects now provide the ordered_attributes and
2237 specified_attributes attributes. A new module expat.model was added,
2238 which offers a number of additional constants if 1.95.x is used.
2239
2240- xml.dom offers the new functions registerDOMImplementation and
2241 getDOMImplementation.
2242
2243- xml.dom.minidom offers a toprettyxml method. A number of DOM
2244 conformance issues have been resolved. In particular, Element now
2245 has an hasAttributes method, and the handling of namespaces was
2246 improved.
2247
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002248- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2249 getting information about live Python code, and pydoc.py, a module
2250 for interactively converting docstrings to HTML or text.
2251 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002252 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002253 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2254 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002255
Tim Peters1eff7962001-03-01 02:31:33 +00002256- New library module difflib.py, primarily packaging the SequenceMatcher
2257 class at the heart of the popular ndiff.py file-comparison tool.
2258
2259- doctest.py (a framework for verifying Python code examples in docstrings)
2260 is now part of the std library.
2261
Tim Petersd66595f2001-02-04 03:09:53 +00002262Windows changes
2263
Guido van Rossume3955a82001-03-02 14:05:59 +00002264- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2265 small GUI that lets you browse the module docstrings using your
2266 default web browser.
2267
Tim Peters1eff7962001-03-01 02:31:33 +00002268- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2269 Platforms) is implemented. See
2270
2271 http://python.sourceforge.net/peps/pep-0235.html
2272
2273 for full details, especially the "Current Lower-Left Semantics" section.
2274 The new Windows import rules are simpler than before:
2275
2276 A. If the PYTHONCASEOK environment variable exists, same as
2277 before: silently accept the first case-insensitive match of any
2278 kind; raise ImportError if none found.
2279
2280 B. Else search sys.path for the first case-sensitive match; raise
2281 ImportError if none found.
2282
2283 The same rules have been implented on other platforms with case-
2284 insensitive but case-preserving filesystems too (including Cygwin, and
2285 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002286
Tim Peters25a9ce32001-02-19 07:06:36 +00002287- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2288 what it's supposed to do (and does do under NT and 2000) via direct
2289 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002290 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002291 all Win9x systems before.
2292
Tim Peters1eff7962001-03-01 02:31:33 +00002293- Build: Subproject _test (effectively) renamed to _testcapi.
2294
Tim Peters2fe289a2001-03-01 22:19:38 +00002295New platforms
2296
2297- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2298 Thanks to Steven Majewski!
2299
2300- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2301 Tishler!
2302
Guido van Rossum9089b272001-03-02 06:49:50 +00002303- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2304 Schwertberger! See RISCOS/README for more information -- it seems
2305 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002306 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002307
Tim Peters25a9ce32001-02-19 07:06:36 +00002308
Tim Petersd7b5e882001-01-25 03:36:26 +00002309What's New in Python 2.1 alpha 2?
2310=================================
Tim Peters40ead762001-01-27 05:35:26 +00002311
Tim Petersd7b5e882001-01-25 03:36:26 +00002312Core language, builtins, and interpreter
2313
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002314- Scopes nest. If a name is used in a function or class, but is not
2315 local, the definition in the nearest enclosing function scope will
2316 be used. One consequence of this change is that lambda statements
2317 could reference variables in the namespaces where the lambda is
2318 defined. In some unusual cases, this change will break code.
2319
2320 In all previous version of Python, names were resolved in exactly
2321 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002322 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002323 function A is defined within a function B, the names bound in B are
2324 not visible in A. The new rules make names bound in B visible in A,
2325 unless A contains a name binding that hides the binding in B.
2326
2327 Section 4.1 of the reference manual describes the new scoping rules
2328 in detail. The test script in Lib/test/test_scope.py demonstrates
2329 some of the effects of the change.
2330
2331 The new rules will cause existing code to break if it defines nested
2332 functions where an outer function has local variables with the same
2333 name as globals or builtins used by the inner function. Example:
2334
2335 def munge(str):
2336 def helper(x):
2337 return str(x)
2338 if type(str) != type(''):
2339 str = helper(str)
2340 return str.strip()
2341
2342 Under the old rules, the name str in helper() is bound to the
2343 builtin function str(). Under the new rules, it will be bound to
2344 the argument named str and an error will occur when helper() is
2345 called.
2346
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002347- The compiler will report a SyntaxError if "from ... import *" occurs
2348 in a function or class scope. The language reference has documented
2349 that this case is illegal, but the compiler never checked for it.
2350 The recent introduction of nested scope makes the meaning of this
2351 form of name binding ambiguous. In a future release, the compiler
2352 may allow this form when there is no possibility of ambiguity.
2353
Tim Peters40ead762001-01-27 05:35:26 +00002354- repr(string) is easier to read, now using hex escapes instead of octal,
2355 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2356
2357 >>> "\texample \r\n" + chr(0) + chr(255)
2358 '\texample \r\n\x00\xff' # in 2.1
2359 '\011example \015\012\000\377' # in 2.0
2360
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002361- Functions are now compared and hashed by identity, not by value, since
2362 the func_code attribute is writable.
2363
Fred Drakefb9d7122001-02-01 20:00:40 +00002364- Weak references (PEP 205) have been added. This involves a few
2365 changes in the core, an extension module (_weakref), and a Python
2366 module (weakref). The weakref module is the public interface. It
2367 includes support for "explicit" weak references, proxy objects, and
2368 mappings with weakly held values.
2369
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002370- A 'continue' statement can now appear in a try block within the body
2371 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002372 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002373
Tim Petersd7b5e882001-01-25 03:36:26 +00002374Standard library
2375
Barry Warsaw30dbd142001-01-31 22:14:01 +00002376- mailbox.py now has a new class, PortableUnixMailbox which is
2377 identical to UnixMailbox but uses a more portable scheme for
2378 determining From_ separators. Also, the constructors for all the
2379 classes in this module have a new optional `factory' argument, which
2380 is a callable used when new message classes must be instantiated by
2381 the next() method.
2382
Tim Petersd7b5e882001-01-25 03:36:26 +00002383- random.py is now self-contained, and offers all the functionality of
2384 the now-deprecated whrandom.py. See the docs for details. random.py
2385 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002386 and restoring the internal state of the generator; and jumpahead(n),
2387 for quickly forcing the internal state to be the same as if n calls to
2388 random() had been made. The latter is particularly useful for multi-
2389 threaded programs, creating one instance of the random.Random() class for
2390 each thread, then using .jumpahead() to force each instance to use a
2391 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002392
Tim Peters0de88fc2001-02-01 04:59:18 +00002393- random.py's seed() function is new. For bit-for-bit compatibility with
2394 prior releases, use the whseed function instead. The new seed function
2395 addresses two problems: (1) The old function couldn't produce more than
2396 about 2**24 distinct internal states; the new one about 2**45 (the best
2397 that can be done in the Wichmann-Hill generator). (2) The old function
2398 sometimes produced identical internal states when passed distinct
2399 integers, and there was no simple way to predict when that would happen;
2400 the new one guarantees to produce distinct internal states for all
2401 arguments in [0, 27814431486576L).
2402
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002403- The socket module now supports raw packets on Linux. The socket
2404 family is AF_PACKET.
2405
Tim Peters9ea17ac2001-02-02 05:57:15 +00002406- test_capi.py is a start at running tests of the Python C API. The tests
2407 are implemented by the new Modules/_testmodule.c.
2408
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002409- A new extension module, _symtable, provides provisional access to the
2410 internal symbol table used by the Python compiler. A higher-level
2411 interface will be added on top of _symtable in a future release.
2412
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002413- Removed the obsolete soundex module.
2414
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002415- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2416 the isSameNode method; NamedNodeMap the get method.
2417
2418- xml.sax.expatreader supports the lexical handler property; it
2419 generates comment, startCDATA, and endCDATA events.
2420
Tim Petersee826f82001-01-31 19:39:44 +00002421Windows changes
2422
2423- Build procedure: the zlib project is built in a different way that
2424 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002425 the zlib binary used. See PCbuild\readme.txt for details. Your old
2426 zlib-related directories can be deleted; you'll need to download fresh
2427 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002428
Tim Peters9ea17ac2001-02-02 05:57:15 +00002429- Build: New subproject _test for the benefit of test_capi.py (see above).
2430
Tim Petersb16c56f2001-02-02 21:24:51 +00002431- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2432 interface to some Python compiler internals).
2433
2434- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002435 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002436
Tim Petersa3a3a032000-11-30 05:22:44 +00002437What's New in Python 2.1 alpha 1?
2438=================================
2439
2440Core language, builtins, and interpreter
2441
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002442- There is a new Unicode companion to the PyObject_Str() API
2443 called PyObject_Unicode(). It behaves in the same way as the
2444 former, but assures that the returned value is an Unicode object
2445 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002446
Guido van Rossumf98eda02001-01-17 15:54:45 +00002447- The comparison operators support "rich comparison overloading" (PEP
2448 207). C extension types can provide a rich comparison function in
2449 the new tp_richcompare slot in the type object. The cmp() function
2450 and the C function PyObject_Compare() first try the new rich
2451 comparison operators before trying the old 3-way comparison. There
2452 is also a new C API PyObject_RichCompare() (which also falls back on
2453 the old 3-way comparison, but does not constrain the outcome of the
2454 rich comparison to a Boolean result).
2455
2456 The rich comparison function takes two objects (at least one of
2457 which is guaranteed to have the type that provided the function) and
2458 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2459 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2460 object, which may be NotImplemented (in which case the tp_compare
2461 slot function is used as a fallback, if defined).
2462
2463 Classes can overload individual comparison operators by defining one
2464 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002465 __ge__. There are no explicit "reflected argument" versions of
2466 these; instead, __lt__ and __gt__ are each other's reflection,
2467 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2468 reflection (similar at the C level). No other implications are
2469 made; in particular, Python does not assume that == is the Boolean
2470 inverse of !=, or that < is the Boolean inverse of >=. This makes
2471 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002472
2473 Classes or types that want to implement (in)equality tests but not
2474 the ordering operators (i.e. unordered types) should implement ==
2475 and !=, and raise an error for the ordering operators.
2476
Guido van Rossuma88479f2001-01-18 14:28:08 +00002477 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002478 Boolean; e.g. a matrix type might want to return a matrix of bits
2479 for A < B, giving elementwise comparisons. Such types should ensure
2480 that any interpretation of their value in a Boolean context raises
2481 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2482 at the C level) to always raise an exception.
2483
Guido van Rossuma88479f2001-01-18 14:28:08 +00002484- Complex numbers use rich comparisons to define == and != but raise
2485 an exception for <, <=, > and >=. Unfortunately, this also means
2486 that cmp() of two complex numbers raises an exception when the two
2487 numbers differ. Since it is not mathematically meaningful to compare
2488 complex numbers except for equality, I hope that this doesn't break
2489 too much code.
2490
Tim Peters3389f192001-02-18 08:48:49 +00002491- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002492 not defined by the language, other than that it's arbitrary but
2493 consistent (see the Reference Manual). An implementation detail changed
2494 in 2.1a1 such that None now compares less than any other object. Code
2495 relying on this new behavior (like code that relied on the previous
2496 behavior) does so at its own risk.
2497
Barry Warsaw573b5412001-01-15 20:43:18 +00002498- Functions and methods now support getting and setting arbitrarily
2499 named attributes (PEP 232). Functions have a new __dict__
2500 (a.k.a. func_dict) which hold the function attributes. Methods get
2501 and set attributes on their underlying im_func. It is a TypeError
2502 to set an attribute on a bound method.
2503
Guido van Rossum051e3352001-01-15 19:11:10 +00002504- The xrange() object implementation has been improved so that
2505 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2506 limitation that in this case len(xrange(sys.maxint)) can't be
2507 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2508 work fine as long as the index i doesn't actually reach 2**31.
2509 (Python uses regular ints for sequence and string indices; fixing
2510 that is much more work.)
2511
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002512- Two changes to from...import:
2513
Guido van Rossumba381232001-02-03 15:06:40 +00002514 1) "from M import X" now works even if (after loading module M)
2515 sys.modules['M'] is not a real module; it's basically a getattr()
2516 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002517
2518 2) "from M import *" now looks for M.__all__ to decide which names to
2519 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2520 filters out names starting with '_' as before. Whether or not
2521 __all__ exists, there's no restriction on the type of M.
2522
Guido van Rossumf61f1662001-01-10 20:13:55 +00002523- File objects have a new method, xreadlines(). This is the fastest
2524 way to iterate over all lines in a file:
2525
2526 for line in file.xreadlines():
2527 ...do something to line...
2528
2529 See the xreadlines module (mentioned below) for how to do this for
2530 other file-like objects.
2531
2532- Even if you don't use file.xreadlines(), you may expect a speedup on
2533 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002534 quite a bit in platform-specific ways: on systems (like Linux) that
2535 support flockfile(), getc_unlocked(), and funlockfile(), those are
2536 used by default. On systems (like Windows) without getc_unlocked(),
2537 a complicated (but still thread-safe) method using fgets() is used by
2538 default.
2539
Tim Petersd52269b2001-01-25 06:23:18 +00002540 You can force use of the fgets() method by #define'ing
2541 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002542 getc_unlocked()).
2543
Tim Petersd52269b2001-01-25 06:23:18 +00002544 You can force fgets() not to be used by #define'ing
2545 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002546 test_bufio.py fails -- and let us know if it does!).
2547
2548- In addition, the fileinput module, while still slower than the other
2549 methods on most platforms, has been sped up too, by using
2550 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002551
2552- Support for run-time warnings has been added, including a new
2553 command line option (-W) to specify the disposition of warnings.
2554 See the description of the warnings module below.
2555
2556- Extensive changes have been made to the coercion code. This mostly
2557 affects extension modules (which can now implement mixed-type
2558 numerical operators without having to use coercion), but
2559 occasionally, in boundary cases the coercion semantics have changed
2560 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002561 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002562 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002563 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002564
Guido van Rossumf98eda02001-01-17 15:54:45 +00002565- In connection with the coercion changes, a new built-in singleton
2566 object, NotImplemented is defined. This can be returned for
2567 operations that wish to indicate they are not implemented for a
2568 particular combination of arguments. From C, this is
2569 Py_NotImplemented.
2570
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002571- The interpreter accepts now bytecode files on the command line even
2572 if they do not have a .pyc or .pyo extension. On Linux, after executing
2573
Martin v. Löwise214baa2001-02-04 22:37:56 +00002574import imp,sys,string
2575magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2576reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2577open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002578
2579 any byte code file can be used as an executable (i.e. as an argument
2580 to execve(2)).
2581
Tim Peters9940b802000-12-01 07:59:35 +00002582- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002583 character. In 1.6 and earlier, they never produced a sign,
2584 and raised an error if the value of the long was too large
2585 to fit in a Python int. In 2.0, they produced a sign if and
2586 only if too large to fit in an int. This was inconsistent
2587 across platforms (because the size of an int varies across
2588 platforms), and inconsistent with hex() and oct(). Example:
2589
2590 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002591 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002592 'ffffffbe' # in 2.0 and before, on 32-bit machines
2593 >>> hex(-0x42L)
2594 '-0x42L' # in all versions of Python
2595
Tim Peters9940b802000-12-01 07:59:35 +00002596 The behavior of %d formats for negative Python longs remains
2597 the same as in 2.0 (although in 1.6 and before, they raised
2598 an error if the long didn't fit in a Python int).
2599
2600 %u formats don't make sense for Python longs, but are allowed
2601 and treated the same as %d in 2.1. In 2.0, a negative long
2602 formatted via %u produced a sign if and only if too large to
2603 fit in an int. In 1.6 and earlier, a negative long formatted
2604 via %u raised an error if it was too big to fit in an int.
2605
Guido van Rossum3661d392000-12-12 22:10:31 +00002606- Dictionary objects have an odd new method, popitem(). This removes
2607 an arbitrary item from the dictionary and returns it (in the form of
2608 a (key, value) pair). This can be useful for algorithms that use a
2609 dictionary as a bag of "to do" items and repeatedly need to pick one
2610 item. Such algorithms normally end up running in quadratic time;
2611 using popitem() they can usually be made to run in linear time.
2612
Tim Peters36cdad12000-12-29 02:06:45 +00002613Standard library
2614
Thomas Woutersfe385252001-01-19 23:16:56 +00002615- In the time module, the time argument to the functions strftime,
2616 localtime, gmtime, asctime and ctime is now optional, defaulting to
2617 the current time (in the local timezone).
2618
Guido van Rossumda91f222001-01-15 16:36:08 +00002619- The ftplib module now defaults to passive mode, which is deemed a
2620 more useful default given that clients are often inside firewalls
2621 these days. Note that this could break if ftplib is used to connect
2622 to a *server* that is inside a firewall, from outside; this is
2623 expected to be a very rare situation. To fix that, you can call
2624 ftp.set_pasv(0).
2625
Martin v. Löwis10a27872001-01-13 09:54:41 +00002626- The module site now treats .pth files not only for path configuration,
2627 but also supports extensions to the initialization code: Lines starting
2628 with import are executed.
2629
Guido van Rossumf61f1662001-01-10 20:13:55 +00002630- There's a new module, warnings, which implements a mechanism for
2631 issuing and filtering warnings. There are some new built-in
2632 exceptions that serve as warning categories, and a new command line
2633 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2634 turns warnings into errors). warnings.warn(message[, category])
2635 issues a warning message; this can also be called from C as
2636 PyErr_Warn(category, message).
2637
2638- A new module xreadlines was added. This exports a single factory
2639 function, xreadlines(). The intention is that this code is the
2640 absolutely fastest way to iterate over all lines in an open
2641 file(-like) object:
2642
2643 import xreadlines
2644 for line in xreadlines.xreadlines(file):
2645 ...do something to line...
2646
2647 This is equivalent to the previous the speed record holder using
2648 file.readlines(sizehint). Note that if file is a real file object
2649 (as opposed to a file-like object), this is equivalent:
2650
2651 for line in file.xreadlines():
2652 ...do something to line...
2653
Tim Peters36cdad12000-12-29 02:06:45 +00002654- The bisect module has new functions bisect_left, insort_left,
2655 bisect_right and insort_right. The old names bisect and insort
2656 are now aliases for bisect_right and insort_right. XXX_right
2657 and XXX_left methods differ in what happens when the new element
2658 compares equal to one or more elements already in the list: the
2659 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002660 right. Code that doesn't care where equal elements end up should
2661 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002662
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002663- The new curses.panel module wraps the panel library that forms part
2664 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2665
Guido van Rossumf61f1662001-01-10 20:13:55 +00002666- The SocketServer module now sets the allow_reuse_address flag by
2667 default in the TCPServer class.
2668
2669- A new function, sys._getframe(), returns the stack frame pointer of
2670 the caller. This is intended only as a building block for
2671 higher-level mechanisms such as string interpolation.
2672
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002673- The pyexpat module supports a number of new handlers, which are
2674 available only in expat 1.2. If invocation of a callback fails, it
2675 will report an additional frame in the traceback. Parser objects
2676 participate now in garbage collection. If expat reports an unknown
2677 encoding, pyexpat will try to use a Python codec; that works only
2678 for single-byte charsets. The parser type objects is exposed as
2679 XMLParserObject.
2680
2681- xml.dom now offers standard definitions for symbolic node type and
2682 exception code constants, and a hierarchy of DOM exceptions. minidom
2683 was adjusted to use them.
2684
2685- The conformance of xml.dom.minidom to the DOM specification was
2686 improved. It detects a number of additional error cases; the
2687 previous/next relationship works even when the tree is modified;
2688 Node supports the normalize() method; NamedNodeMap, DocumentType and
2689 DOMImplementation classes were added; Element supports the
2690 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2691 method.
2692
Guido van Rossumf61f1662001-01-10 20:13:55 +00002693Build issues
2694
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002695- For Unix (and Unix-compatible) builds, configuration and building of
2696 extension modules is now greatly automated. Rather than having to
2697 edit the Modules/Setup file to indicate which modules should be
2698 built and where their include files and libraries are, a
2699 distutils-based setup.py script now takes care of building most
2700 extension modules. All extension modules built this way are built
2701 as shared libraries. Only a few modules that must be linked
2702 statically are still listed in the Setup file; you won't need to
2703 edit their configuration.
2704
2705- Python should now build out of the box on Cygwin. If it doesn't,
2706 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002707
2708- Python now always uses its own (renamed) implementation of getopt()
2709 -- there's too much variation among C library getopt()
2710 implementations.
2711
2712- C++ compilers are better supported; the CXX macro is always set to a
2713 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002714
Tim Petersd92dfe02000-12-12 01:18:41 +00002715Windows changes
2716
2717- select module: By default under Windows, a select() call
2718 can specify no more than 64 sockets. Python now boosts
2719 this Microsoft default to 512. If you need even more than
2720 that, see the MS docs (you'll need to #define FD_SETSIZE
2721 and recompile Python from source).
2722
Guido van Rossumf61f1662001-01-10 20:13:55 +00002723- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2724 subdirectory is no more!
2725
Tim Petersa3a3a032000-11-30 05:22:44 +00002726
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002727What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002728=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002729
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002730Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002731changes are in the file HISTORY. If you are making the jump directly
2732from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2733HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002734
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002735Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2736the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2737http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002738
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002739--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002740
2741======================================================================
2742
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002743What's new in 2.0 (since release candidate 1)?
2744==============================================
2745
2746Standard library
2747
2748- The copy_reg module was modified to clarify its intended use: to
2749 register pickle support for extension types, not for classes.
2750 pickle() will raise a TypeError if it is passed a class.
2751
2752- Fixed a bug in gettext's "normalize and expand" code that prevented
2753 it from finding an existing .mo file.
2754
2755- Restored support for HTTP/0.9 servers in httplib.
2756
Tim Peters989b7b92000-10-16 20:24:53 +00002757- The math module was changed to stop raising OverflowError in case of
2758 underflow, and return 0 instead in underflow cases. Whether Python
2759 used to raise OverflowError in case of underflow was platform-
2760 dependent (it did when the platform math library set errno to ERANGE
2761 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002762
2763- Fixed a bug in StringIO that occurred when the file position was not
2764 at the end of the file and write() was called with enough data to
2765 extend past the end of the file.
2766
2767- Fixed a bug that caused Tkinter error messages to get lost on
2768 Windows. The bug was fixed by replacing direct use of
2769 interp->result with Tcl_GetStringResult(interp).
2770
2771- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2772 redirect response.
2773
2774- Several changes were made to distutils: Some debugging code was
2775 removed from util. Fixed the installer used when an external zip
2776 program (like WinZip) is not found; the source code for this
2777 installer is in Misc/distutils. check_lib() was modified to behave
2778 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2779 test for whether installed modules are on sys.path was changed to
2780 use both normcase() and normpath().
2781
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002782- Several minor bugs were fixed in the xml package (the minidom,
2783 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002784
2785- The regression test driver (regrtest.py) behavior when invoked with
2786 -l changed: It now reports a count of objects that are recognized as
2787 garbage but not freed by the garbage collector.
2788
Tim Peters989b7b92000-10-16 20:24:53 +00002789- The regression test for the math module was changed to test
2790 exceptional behavior when the test is run in verbose mode. Python
2791 cannot yet guarantee consistent exception behavior across platforms,
2792 so the exception part of test_math is run only in verbose mode, and
2793 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002794
2795Internals
2796
2797- PyOS_CheckStack() has been disabled on Win64, where it caused
2798 test_sre to fail.
2799
2800Build issues
2801
2802- Changed compiler flags, so that gcc is always invoked with -Wall and
2803 -Wstrict-prototypes. Users compiling Python with GCC should see
2804 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002805 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002806 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002807
Tim Petersa3a3a032000-11-30 05:22:44 +00002808- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002809
2810Tools and other miscellany
2811
2812- The compiler in Tools/compiler was updated to support the new
2813 language features introduced in 2.0: extended print statement, list
2814 comprehensions, and augmented assignments. The new compiler should
2815 also be backwards compatible with Python 1.5.2; the compiler will
2816 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002817 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002818
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002819What's new in 2.0 release candidate 1 (since beta 2)?
2820=====================================================
2821
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002822What is release candidate 1?
2823
2824We believe that release candidate 1 will fix all known bugs that we
2825intend to fix for the 2.0 final release. This release should be a bit
2826more stable than the previous betas. We would like to see even more
2827widespread testing before the final release, so we are producing this
2828release candidate. The final release will be exactly the same unless
2829any show-stopping (or brown bag) bugs are found by testers of the
2830release candidate.
2831
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002832All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002833to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002834
2835Core language, builtins, and interpreter
2836
2837- A bug that caused crashes when __coerce__ was used with augmented
2838 assignment, e.g. +=, was fixed.
2839
2840- Raise ZeroDivisionError when raising zero to a negative number,
2841 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2842 power operator and the result of math.pow(0.0, -2.0) will vary by
2843 platform. On Linux, it raises a ValueError.
2844
2845- A bug in Unicode string interpolation was fixed that occasionally
2846 caused errors with formats including "%%". For example, the
2847 following expression "%% %s" % u"abc" no longer raises a TypeError.
2848
2849- Compilation of deeply nested expressions raises MemoryError instead
2850 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2851
2852- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2853 rendering them useless. They are now written in binary mode again.
2854
2855Standard library
2856
2857- Keyword arguments are now accepted for most pattern and match object
2858 methods in SRE, the standard regular expression engine.
2859
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002860- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002861 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002862
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002863- Several bugs in the Unicode handling and error handling in _tkinter
2864 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002865
2866- Fix memory management errors in Merge() and Tkapp_Call() routines.
2867
2868- Several changes were made to cStringIO to make it compatible with
2869 the file-like object interface and with StringIO. If operations are
2870 performed on a closed object, an exception is raised. The truncate
2871 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002872 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002873
2874- There were many changes made to the linuxaudiodev module and its
2875 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002876 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002877
2878 Note that this module is named poorly, because it should work
2879 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002880 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002881
2882 The module now raises exceptions when errors occur instead of
2883 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2884 audio) and defines a getptr() method that calls the
2885 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2886
2887- The library_version attribute, introduced in an earlier beta, was
2888 removed because it can not be supported with early versions of the C
2889 readline library, which provides no way to determine the version at
2890 compile-time.
2891
2892- The binascii module is now enabled on Win64.
2893
Tim Peters46446d62000-10-09 21:19:31 +00002894- tokenize.py no longer suffers "recursion depth" errors when parsing
2895 programs with very long string literals.
2896
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002897Internals
2898
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002899- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002900 which is called when the interpreter starts up to determine where
2901 the standard library is installed. These vulnerabilities affect all
2902 previous versions of Python and can be exploited by setting very
2903 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2904 setuid Python script, although use of the wrapper in
2905 Misc/setuid-prog.c will eliminate the vulnerability.
2906
2907- Fixed garbage collection bugs in instance creation that were
2908 triggered when errors occurred during initialization. The solution,
2909 applied in cPickle and in PyInstance_New(), is to call
2910 PyObject_GC_Init() after the initialization of the object's
2911 container attributes is complete.
2912
2913- pyexpat adds definitions of PyModule_AddStringConstant and
2914 PyModule_AddObject if the Python version is less than 2.0, which
2915 provides compatibility with PyXML on Python 1.5.2.
2916
2917- If the platform has a bogus definition for LONG_BIT (the number of
2918 bits in a long), an error will be reported at compile time.
2919
2920- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2921 collection crashes and possibly other, unreported crashes.
2922
2923- Fixed a memory leak in _PyUnicode_Fini().
2924
2925Build issues
2926
2927- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002928 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002929 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002930
2931- The mmap.PAGESIZE constant is now initialized using sysconf when
2932 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2933
2934- The md5 file should now compile on all platforms.
2935
2936- The select module now compiles on platforms that do not define
2937 POLLRDNORM and related constants.
2938
2939- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002940 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002941
Jeremy Hylton10921202000-10-09 18:34:12 +00002942- BeOS: A number of changes were made to the build and installation
2943 process. ar-fake now operates on a directory of object files.
2944 dl_export.h is gone, and its macros now appear on the mwcc command
2945 line during build on PPC BeOS.
2946
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002947- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002948 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002949
2950- Cygwin: Support for shared libraries, Tkinter, and sockets.
2951
2952- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2953
2954Tools and other miscellany
2955
2956- Removed debugging prints from main used with freeze.
2957
Tim Peters46446d62000-10-09 21:19:31 +00002958- IDLE auto-indent no longer crashes when it encounters Unicode
2959 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002960
2961What's new in 2.0 beta 2 (since beta 1)?
2962========================================
2963
2964Core language, builtins, and interpreter
2965
Tim Peters482c0212000-09-26 06:33:09 +00002966- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002967 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002968
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002969- Add -h and -V command line options to print the usage message and
2970 Python version number and exit immediately.
2971
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002972- eval() and exec accept Unicode objects as code parameters.
2973
2974- getattr() and setattr() now also accept Unicode objects for the
2975 attribute name, which are converted to strings using the default
2976 encoding before lookup.
2977
2978- Multiplication on string and Unicode now does proper bounds
2979 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2980 string is too long."
2981
2982- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002983 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002984
Jeremy Hylton1b618592000-09-26 05:32:36 +00002985
2986Standard library and extensions
2987
Guido van Rossum5b08f132001-04-16 02:05:23 +00002988- socket module: the OpenSSL code now adds support for RAND_status()
2989 and EGD (Entropy Gathering Device).
2990
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002991- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002992 argument checking; it still takes no arguments.
2993
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002994- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002995
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002996- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002997
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002998- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002999
3000- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003001 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003002
3003- copy: Copy Unicode objects atomically.
3004
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003005- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003006
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003007- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003008
Fred Drake67233bc2000-09-26 16:40:27 +00003009- dbm: Add get() and setdefault() methods to dbm object. Add constant
3010 `library' to module that names the library used. Added doc strings
3011 and method names to error messages. Uses configure to determine
3012 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
3013 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003014
3015- distutils: Update to version 0.9.3.
3016
3017- dl: Add several dl.RTLD_ constants.
3018
3019- fpectl: Now supported on FreeBSD.
3020
3021- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
3022 found by the collector will be saved in gc.garbage. This is useful
3023 for debugging a program that creates reference cycles.
3024
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003025- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003026 of HTTP class. Do not close socket on zero-length response. Do not
3027 crash when server sends invalid content-length header.
3028
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003029- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003030
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003031- marshal: When reading a short, sign-extend on platforms where shorts
3032 are bigger than 16 bits. When reading a long, repair the unportable
3033 sign extension that was being done for 64-bit machines. (It assumed
3034 that signed right shift sign-extends.)
3035
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003036- operator: Add contains(), invert(), __invert__() as aliases for
3037 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003038
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003039- os: Add support for popen2() and popen3() on all platforms where
3040 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003041
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003042- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003043 clicking on a file in Explorer (or passing the file name to the
3044 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003045
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003046- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003047 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003048
3049- pickle: Now raises ValueError when an invalid pickle that contains
3050 a non-string repr where a string repr was expected. This behavior
3051 matches cPickle.
3052
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003053- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003054
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003055- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003056
3057- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003058 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003059 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003060
3061- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003062 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003063
3064- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003065 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003066 few cycles during startup since the first call to
3067 setdefaultencoding() will initialize the codec registry and the
3068 encodings package.
3069
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003070- socket: Support for size hint in readlines() method of object returned
3071 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003072
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003073- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003074 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003075 is followed by whitespace.
3076
Tim Petersa3a3a032000-11-30 05:22:44 +00003077- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003078
3079- struct: Check ranges for bytes and shorts.
3080
3081- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003082 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003083
3084- Tkinter: Image objects are now guaranteed to have unique ids. Set
3085 event.delta to zero if Tk version doesn't support mousewheel.
3086 Removed some debugging prints.
3087
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003088- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003089
Fred Drake67233bc2000-09-26 16:40:27 +00003090- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003091 which works around a bug in Norton AntiVirus 2000 that leads directly
3092 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003093
3094- xml: New version detection code allows PyXML to override standard
3095 XML package if PyXML version is greater than 0.6.1.
3096
Fred Drake64bb3802000-09-26 16:21:35 +00003097- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3098 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3099 tree only for nodes which are sufficiently interesting to a specific
3100 application. Does not provide the HTML-specific extensions. Still
3101 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003102
Fred Drake64bb3802000-09-26 16:21:35 +00003103- xml.sax: SAX 2 support for Python, including all the handler
3104 interfaces needed to process XML 1.0 compliant XML. Some
3105 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003106
Fred Drake64bb3802000-09-26 16:21:35 +00003107- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3108 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003109
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003110
Jeremy Hylton1b618592000-09-26 05:32:36 +00003111C API
3112
3113- Add three new convenience functions for module initialization --
3114 PyModule_AddObject(), PyModule_AddIntConstant(), and
3115 PyModule_AddStringConstant().
3116
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003117- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003118 removed and add #error to Python.h if NULL isn't defined after
3119 #include of stdio.h.
3120
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003121- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003122 backwards compatibility (at the source level) with old extensions.
3123
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003124- A wrapper API was added for signal() and sigaction(). Instead of
3125 either function, always use PyOS_getsig() to get a signal handler
3126 and PyOS_setsig() to set one. A new convenience typedef
3127 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003128
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003129- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003130 internal data buffer and size of a string object -- or the default
3131 encoded version of a Unicode object.
3132
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003133- PyString_Size() and PyString_AsString() accept Unicode objects.
3134
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003135- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003136 exists). INT_MAX and LONG_MAX will always be defined, even if
3137 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003138
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003139- PyFloat_FromString takes a second argument, pend, that was
3140 effectively useless. It is now officially useless but preserved for
3141 backwards compatibility. If the pend argument is not NULL, *pend is
3142 set to NULL.
3143
3144- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3145 for the attribute name. See note on getattr() above.
3146
3147- A few bug fixes to argument processing for Unicode.
3148 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3149 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3150 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003151 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003152
3153- Py_BuildValue accepts B format (for bgen-generated code).
3154
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003155
Jeremy Hylton1b618592000-09-26 05:32:36 +00003156Internals
3157
3158- On Unix, fix code for finding Python installation directory so that
3159 it works when argv[0] is a relative path.
3160
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003161- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003162 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003163 rather than by generating a copy of the object.
3164
Tim Peters482c0212000-09-26 06:33:09 +00003165- Several of the internal Unicode tables are much smaller now, and
3166 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003167
Jeremy Hylton97693b02000-09-26 17:42:51 +00003168- In the garbage collector: Fixed bug in collection of tuples. Fixed
3169 bug that caused some instances to be removed from the container set
3170 while they were still live. Fixed parsing in gc.set_debug() for
3171 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003172
3173- Fixed refcount problem in instance deallocation that only occurred
3174 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3175
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003176- On Windows, getpythonregpath is now protected against null data in
3177 registry key.
3178
3179- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003180 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003181
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003182
Jeremy Hylton1b618592000-09-26 05:32:36 +00003183Build and platform-specific issues
3184
3185- Better support of GNU Pth via --with-pth configure option.
3186
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003187- Python/C API now properly exposed to dynamically-loaded extension
3188 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003189
3190- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3191 Don't define MS_SYNC to be zero when it is undefined. Added missing
3192 prototypes in posixmodule.c.
3193
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003194- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003195 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003196
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003197- Fix largefile support on older NetBSD systems and OpenBSD by adding
3198 define for TELL64.
3199
3200
3201Tools and other miscellany
3202
3203- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3204
3205- freeze: The modulefinder now works with 2.0 opcodes.
3206
Tim Petersa3a3a032000-11-30 05:22:44 +00003207- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003208 Move hackery of sys.argv until after the Tk instance has been
3209 created, which allows the application-specific Tkinter
3210 initialization to be executed if present; also pass an explicit
3211 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003212
Jeremy Hylton1b618592000-09-26 05:32:36 +00003213
3214What's new in 2.0 beta 1?
3215=========================
3216
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003217Source Incompatibilities
3218------------------------
3219
3220None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3221such as single-argument append(), connect() and bind(), and changes to
3222str(long) and repr(float).
3223
3224
3225Binary Incompatibilities
3226------------------------
3227
3228- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3229with Python 2.0; these extensions will have to be rebuilt for Python
32302.0.
3231
3232- On Windows, attempting to import a third party extension built for
3233Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3234can do about this. Check your PYTHONPATH environment variable!
3235
3236- Python bytecode files (*.pyc and *.pyo) are not compatible between
3237releases.
3238
3239
3240Overview of Changes Since 1.6
3241-----------------------------
3242
3243There are many new modules (including brand new XML support through
3244the xml package, and i18n support through the gettext module); a list
3245of all new modules is included below. Lots of bugs have been fixed.
3246
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003247The process for making major new changes to the language has changed
3248since Python 1.6. Enhancements must now be documented by a Python
3249Enhancement Proposal (PEP) before they can be accepted.
3250
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003251There are several important syntax enhancements, described in more
3252detail below:
3253
3254 - Augmented assignment, e.g. x += 1
3255
3256 - List comprehensions, e.g. [x**2 for x in range(10)]
3257
3258 - Extended import statement, e.g. import Module as Name
3259
3260 - Extended print statement, e.g. print >> file, "Hello"
3261
3262Other important changes:
3263
3264 - Optional collection of cyclical garbage
3265
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003266Python Enhancement Proposal (PEP)
3267---------------------------------
3268
3269PEP stands for Python Enhancement Proposal. A PEP is a design
3270document providing information to the Python community, or describing
3271a new feature for Python. The PEP should provide a concise technical
3272specification of the feature and a rationale for the feature.
3273
3274We intend PEPs to be the primary mechanisms for proposing new
3275features, for collecting community input on an issue, and for
3276documenting the design decisions that have gone into Python. The PEP
3277author is responsible for building consensus within the community and
3278documenting dissenting opinions.
3279
3280The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003281
3282Augmented Assignment
3283--------------------
3284
3285This must have been the most-requested feature of the past years!
3286Eleven new assignment operators were added:
3287
Guido van Rossume905e952000-09-05 12:42:46 +00003288 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003289
3290For example,
3291
3292 A += B
3293
3294is similar to
3295
3296 A = A + B
3297
3298except that A is evaluated only once (relevant when A is something
3299like dict[index].attr).
3300
3301However, if A is a mutable object, A may be modified in place. Thus,
3302if A is a number or a string, A += B has the same effect as A = A+B
3303(except A is only evaluated once); but if a is a list, A += B has the
3304same effect as A.extend(B)!
3305
3306Classes and built-in object types can override the new operators in
3307order to implement the in-place behavior; the not-in-place behavior is
3308used automatically as a fallback when an object doesn't implement the
3309in-place behavior. For classes, the method name is derived from the
3310method name for the corresponding not-in-place operator by inserting
3311an 'i' in front of the name, e.g. __iadd__ implements in-place
3312__add__.
3313
3314Augmented assignment was implemented by Thomas Wouters.
3315
3316
3317List Comprehensions
3318-------------------
3319
3320This is a flexible new notation for lists whose elements are computed
3321from another list (or lists). The simplest form is:
3322
3323 [<expression> for <variable> in <sequence>]
3324
Guido van Rossum56db0952000-09-06 23:34:25 +00003325For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003326This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003327
3328You can also add a condition:
3329
3330 [<expression> for <variable> in <sequence> if <condition>]
3331
3332For example, [w for w in words if w == w.lower()] would yield the list
3333of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003334than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003335
3336You can also have nested for loops and more than one 'if' clause. For
3337example, here's a function that flattens a sequence of sequences::
3338
3339 def flatten(seq):
3340 return [x for subseq in seq for x in subseq]
3341
3342 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3343
3344This prints
3345
3346 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3347
3348List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003349Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003350
3351
3352Extended Import Statement
3353-------------------------
3354
3355Many people have asked for a way to import a module under a different
3356name. This can be accomplished like this:
3357
3358 import foo
3359 bar = foo
3360 del foo
3361
3362but this common idiom gets old quickly. A simple extension of the
3363import statement now allows this to be written as follows:
3364
3365 import foo as bar
3366
3367There's also a variant for 'from ... import':
3368
3369 from foo import bar as spam
3370
3371This also works with packages; e.g. you can write this:
3372
3373 import test.regrtest as regrtest
3374
3375Note that 'as' is not a new keyword -- it is recognized only in this
3376context (this is only possible because the syntax for the import
3377statement doesn't involve expressions).
3378
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003379Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003380
3381
3382Extended Print Statement
3383------------------------
3384
3385Easily the most controversial new feature, this extension to the print
3386statement adds an option to make the output go to a different file
3387than the default sys.stdout.
3388
3389For example, to write an error message to sys.stderr, you can now
3390write:
3391
3392 print >> sys.stderr, "Error: bad dog!"
3393
3394As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003395evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003396
3397 print >> None, "Hello world"
3398
3399is equivalent to
3400
3401 print "Hello world"
3402
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003403Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003404
3405
3406Optional Collection of Cyclical Garbage
3407---------------------------------------
3408
3409Python is now equipped with a garbage collector that can hunt down
3410cyclical references between Python objects. It's no replacement for
3411reference counting; in fact, it depends on the reference counts being
3412correct, and decides that a set of objects belong to a cycle if all
3413their reference counts can be accounted for from their references to
3414each other. This devious scheme was first proposed by Eric Tiedemann,
3415and brought to implementation by Neil Schemenauer.
3416
3417There's a module "gc" that lets you control some parameters of the
3418garbage collection. There's also an option to the configure script
3419that lets you enable or disable the garbage collection. In 2.0b1,
3420it's on by default, so that we (hopefully) can collect decent user
3421experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003422performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003423off by default in the final 2.0 release.
3424
3425
3426Smaller Changes
3427---------------
3428
3429A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3430map(None, seq1, seq2, ...) when the sequences have the same length;
3431i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3432the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003433zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003434
3435sys.version_info is a tuple (major, minor, micro, level, serial).
3436
3437Dictionaries have an odd new method, setdefault(key, default).
3438dict.setdefault(key, default) returns dict[key] if it exists; if not,
3439it sets dict[key] to default and returns that value. Thus:
3440
3441 dict.setdefault(key, []).append(item)
3442
3443does the same work as this common idiom:
3444
3445 if not dict.has_key(key):
3446 dict[key] = []
3447 dict[key].append(item)
3448
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003449There are two new variants of SyntaxError that are raised for
3450indentation-related errors: IndentationError and TabError.
3451
3452Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3453escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003454
3455The limits on the size of expressions and file in Python source code
3456have been raised from 2**16 to 2**32. Previous versions of Python
3457were limited because the maximum argument size the Python VM accepted
3458was 2**16. This limited the size of object constructor expressions,
3459e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3460limit was raised thanks to a patch by Charles Waldman that effectively
3461fixes the problem. It is now much more likely that you will be
3462limited by available memory than by an arbitrary limit in Python.
3463
3464The interpreter's maximum recursion depth can be modified by Python
3465programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3466limit is the maximum number of recursive calls that can be made by
3467Python code. The limit exists to prevent infinite recursion from
3468overflowing the C stack and causing a core dump. The default value is
34691000. The maximum safe value for a particular platform can be found
3470by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003471
3472New Modules and Packages
3473------------------------
3474
3475atexit - for registering functions to be called when Python exits.
3476
3477imputil - Greg Stein's alternative API for writing custom import
3478hooks.
3479
3480pyexpat - an interface to the Expat XML parser, contributed by Paul
3481Prescod.
3482
3483xml - a new package with XML support code organized (so far) in three
3484subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3485would fill a volume. There's a special feature whereby a
3486user-installed package named _xmlplus overrides the standard
3487xmlpackage; this is intended to give the XML SIG a hook to distribute
3488backwards-compatible updates to the standard xml package.
3489
3490webbrowser - a platform-independent API to launch a web browser.
3491
3492
Guido van Rossume905e952000-09-05 12:42:46 +00003493Changed Modules
3494---------------
3495
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003496array -- new methods for array objects: count, extend, index, pop, and
3497remove
3498
3499binascii -- new functions b2a_hex and a2b_hex that convert between
3500binary data and its hex representation
3501
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003502calendar -- Many new functions that support features including control
3503over which day of the week is the first day, returning strings instead
3504of printing them. Also new symbolic constants for days of week,
3505e.g. MONDAY, ..., SUNDAY.
3506
3507cgi -- FieldStorage objects have a getvalue method that works like a
3508dictionary's get method and returns the value attribute of the object.
3509
3510ConfigParser -- The parser object has new methods has_option,
3511remove_section, remove_option, set, and write. They allow the module
3512to be used for writing config files as well as reading them.
3513
3514ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003515optionally support the RFC 959 REST command.
3516
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003517gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003518
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003519httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3520the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003521
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003522locale -- implement getdefaultlocale for Win32 and Macintosh
3523
3524marshal -- no longer dumps core when marshaling deeply nested or
3525recursive data structures
3526
3527os -- new functions isatty, seteuid, setegid, setreuid, setregid
3528
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003529os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3530support under Unix.
3531
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003532os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003533
3534os.path -- fix semantics of os.path.commonprefix
3535
3536smtplib -- support for sending very long messages
3537
3538socket -- new function getfqdn()
3539
3540readline -- new functions to read, write and truncate history files.
3541The readline section of the library reference manual contains an
3542example.
3543
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003544select -- add interface to poll system call
3545
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003546shutil -- new copyfileobj function
3547
3548SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3549HTTP server.
3550
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003551Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003552
3553urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003554e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003555
3556whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003557
3558
3559Obsolete Modules
3560----------------
3561
3562None. However note that 1.6 made a whole slew of modules obsolete:
3563stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3564poly, zmod, strop, util, whatsound.
3565
3566
3567Changed, New, Obsolete Tools
3568----------------------------
3569
Tim Peters8b092332000-09-05 20:15:25 +00003570None.
Guido van Rossume905e952000-09-05 12:42:46 +00003571
3572
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003573C-level Changes
3574---------------
3575
3576Several cleanup jobs were carried out throughout the source code.
3577
3578All C code was converted to ANSI C; we got rid of all uses of the
3579Py_PROTO() macro, which makes the header files a lot more readable.
3580
3581Most of the portability hacks were moved to a new header file,
3582pyport.h; several other new header files were added and some old
3583header files were removed, in an attempt to create a more rational set
3584of header files. (Few of these ever need to be included explicitly;
3585they are all included by Python.h.)
3586
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003587Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003588and Win64, especially for the new Intel Itanium processor. Mick also
3589added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003590
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003591The C APIs to return an object's size have been update to consistently
3592use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3593previous versions, the abstract interfaces used PyXXX_Length and the
3594concrete interfaces used PyXXX_Size. The old names,
3595e.g. PyObject_Length, are still available for backwards compatibility
3596at the API level, but are deprecated.
3597
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003598The PyOS_CheckStack function has been implemented on Windows by
3599Fredrik Lundh. It prevents Python from failing with a stack overflow
3600on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003601
3602The GC changes resulted in creation of two new slots on object,
3603tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003604the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003605
3606The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003607C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003608
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003609PyErr_Format has been updated to automatically calculate the size of
3610the buffer needed to hold the formatted result string. This change
3611prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003612
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003613New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003614
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003615PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3616that are the same as their non-Ex counterparts except they take an
3617extra flag argument that tells them to close the file when done.
3618
3619XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003620
Tim Peters8b092332000-09-05 20:15:25 +00003621
3622Windows Changes
3623---------------
3624
3625New popen2/popen3/peopen4 in os module (see Changed Modules above).
3626
3627os.popen is much more usable on Windows 95 and 98. See Microsoft
3628Knowledge Base article Q150956. The Win9x workaround described there
3629is implemented by the new w9xpopen.exe helper in the root of your
3630Python installation. Note that Python uses this internally; it is not
3631a standalone program.
3632
3633Administrator privileges are no longer required to install Python
3634on Windows NT or Windows 2000. If you have administrator privileges,
3635Python's registry info will be written under HKEY_LOCAL_MACHINE.
3636Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003637under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003638uses of Python, but will prevent some advanced uses from working
3639(for example, running a Python script as an NT service, or possibly
3640from CGI).
3641
3642[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3643installer; instead, it installs the needed Tcl/Tk files directly in the
3644Python directory. If you already have a Tcl/Tk installation, this
3645wastes some disk space (about 4 Megs) but avoids problems with
3646conflicting Tcl/Tk installations, and makes it much easier for Python
3647to ensure that Tcl/Tk can find all its files.
3648
3649[This was new in 1.6] The Windows installer now installs by default in
3650\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3651
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003652
3653Updates to the changes between 1.5.2 and 1.6
3654--------------------------------------------
3655
3656The 1.6 NEWS file can't be changed after the release is done, so here
3657is some late-breaking news:
3658
3659New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3660and changes to getlocale() and setlocale().
3661
3662The new module is now enabled per default.
3663
3664It is not true that the encodings codecs cannot be used for normal
3665strings: the string.encode() (which is also present on 8-bit strings
3666!) allows using them for 8-bit strings too, e.g. to convert files from
3667cp1252 (Windows) to latin-1 or vice-versa.
3668
3669Japanese codecs are available from Tamito KAJIYAMA:
3670http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3671
3672
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003673======================================================================