blob: 710b748904e7df6821b88bd3a406c56eaa1ee730 [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Guido van Rossum2d5389c2002-07-23 03:44:35 +00009- All standard iterators now ensure that, once StopIteration has been
10 raised, all future calls to next() on the same iterator will also
11 raise StopIteration. There used to be various counterexamples to
12 this behavior, which could caused confusion or subtle program
13 breakage, without any benefits. (Note that this is still an
14 iterator's responsibility; the iterator framework does not enforce
15 this.)
16
Mark Hammondc0e35152002-07-16 01:32:30 +000017- Ctrl+C handling on Windows has been made more consistent with
18 other platforms. KeyboardInterrupt can now reliably be caught,
19 and Ctrl+C at an interative prompt no longer terminates the
20 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
21 interrupt time.sleep() in the main thread, and any child processes
22 created via the popen family are also interrupted (as generally
23 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
24
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000025- Slices and repetitions of buffer objects now consistently return
26 a string. Formerly, strings would be returned most of the time,
27 but a buffer object would be returned when the repetition count
28 was one or when the slice range was all inclusive.
29
Guido van Rossumc7c36502002-06-21 01:29:25 +000030- The __slots__ variable can now mention "private" names, and the
31 right thing will happen (e.g. __slots__ = ["__foo"]).
32
Walter Dörwald3430d702002-06-17 10:43:59 +000033- Unicode objects in sys.path are no longer ignored but treated
34 as directory names.
35
Guido van Rossum9562bcf2002-06-14 21:31:18 +000036- The built-ins slice() and buffer() are now callable types. The
37 types classobj (formerly class), code, function, instance, and
38 instancemethod (formerly instance-method), which have no built-in
39 names but are accessible through the types module, are now also
40 callable. The type dict-proxy is renamed to dictproxy.
41
Neal Norwitz1f68fc72002-06-14 00:50:42 +000042- Fixed string.startswith and string.endswith builtin methods
43 so they accept negative indices. [SF bug 493951]
44
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000045- Fixed a bug with a continue inside a try block and a yield in the
46 finally clause. [SF bug 567538]
47
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000048- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000049 with a third "stride" parameter. For example, "hello world"[::-1]
50 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000051
Guido van Rossum9f7549b2002-06-10 21:39:42 +000052- Cycles going through the __class__ link of a new-style instance are
53 now detected by the garbage collector.
54
Guido van Rossum9923ffe2002-06-04 19:52:53 +000055- Classes using __slots__ are now properly garbage collected.
56 [SF bug 519621]
57
58- Tightened the __slots__ rules: a slot name must be a valid Python
59 identifier.
60
Guido van Rossum2e4e0262002-06-04 05:58:34 +000061- The constructor for the module type now requires a name argument and
62 takes an optional docstring argument. Previously, this constructor
63 ignored its arguments. As a consequence, deriving a class from a
64 module (not from the module type) is now illegal; previously this
65 created an unnamed module, just like invoking the module type did.
66 [SF bug 563060]
67
Neal Norwitzd68f5172002-05-29 15:54:55 +000068- A new warning PendingDeprecationWarning was added to provide
69 direction on features which are in the process of being deprecated.
70 The warning will not be printed by default. To see the pending
71 deprecations, use -Walways::PendingDeprecationWarning::
72 as a command line option or warnings.filterwarnings() in code.
73
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000074- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000075 for 'str' and 'unicode', and can be used instead of
76 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000077 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000078 is an abstract base class and cannot be instantiated directly.
79
Fred Draked0ba6362002-05-02 21:28:26 +000080- Deprecated features of xrange objects have been removed as
81 promised. The start, stop, and step attributes and the tolist()
82 method no longer exist. xrange repetition and slicing have been
83 removed.
84
Guido van Rossum7dab2422002-04-26 19:40:56 +000085- New builtin function enumerate(x), from PEP 279. Example:
86 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
87 The argument can be an arbitrary iterable object.
88
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000089- The assert statement no longer tests __debug__ at runtime. This means
90 that assert statements cannot be disabled by assigning a false value
91 to __debug__.
92
Walter Dörwald068325e2002-04-15 13:36:47 +000093- A method zfill() was added to str and unicode, that fills a numeric
94 string to the left with zeros. For example,
95 "+123".zfill(6) -> "+00123".
96
Guido van Rossum862fe3c2002-04-15 12:36:47 +000097- Complex numbers supported divmod() and the // and % operators, but
98 these make no sense. Since this was documented, they're being
99 deprecated now.
100
Guido van Rossum26dd8302002-04-26 20:11:29 +0000101- String and unicode methods lstrip(), rstrip() and strip() now take
102 an optional argument that specifies the characters to strip. For
103 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000104
Guido van Rossumc69343b2002-04-12 19:22:48 +0000105- Added a new dict method pop(key). This removes and returns the
106 value corresponding to key. [SF patch #539949]
107
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000108- Changed new-style class instantiation so that when C's __new__
109 method returns something that's not a C instance, its __init__ is
110 not called. [SF bug #537450]
111
Guido van Rossum181e41a2002-04-06 00:23:25 +0000112- Fixed super() to work correctly with class methods. [SF bug #535444]
113
Guido van Rossum47834462002-04-04 15:21:33 +0000114- A new built-in type, bool, has been added, as well as built-in
115 names for its two values, True and False. Comparisons and sundry
116 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000117 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000118 is backward compatible.
119
Guido van Rossum95b62a62002-03-29 01:07:24 +0000120- Fixed two bugs reported as SF #535905: under certain conditions,
121 deallocating a deeply nested structure could cause a segfault in the
122 garbage collector, due to interaction with the "trashcan" code;
123 access to the current frame during destruction of a local variable
124 could access a pointer to freed memory.
125
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000126- The optional object allocator ("pymalloc") has been enabled by
127 default. The recommended practice for memory allocation and
128 deallocation has been streamlined. A header file is included,
129 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
130 and lets them use the same API with Python versions from 1.5.2
131 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000132
Guido van Rossum8c842552002-03-14 23:05:54 +0000133- If you try to pickle an instance of a class that has __slots__ but
134 doesn't define or override __getstate__, a TypeError is now raised.
135 This is done by adding a bozo __getstate__ to the class that always
136 raises TypeError. (Before, this would appear to be pickled, but the
137 state of the slots would be lost.)
138
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000139- PyErr_Display will provide file and line information for all exceptions
140 that have an attribute print_file_and_line, not just SyntaxErrors.
141
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000142- The UTF-8 codec will now encode and decode Unicode surrogates
143 correctly and without raising exceptions for unpaired ones.
144
Neal Norwitz649b7592002-01-01 19:07:13 +0000145- file.xreadlines() now raises a ValueError if the file is closed:
146 Previously, an xreadlines object was returned which would raise
147 a ValueError when the xreadlines.next() method was called.
148
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000149- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000150 An exception will now be raised if more than one argument is used.
151
Tim Petersaf8446f2001-12-21 21:36:50 +0000152Extension modules
153
Guido van Rossum79f0a102002-07-23 03:32:08 +0000154- The strptime function in the time module is now always available (a
155 Python implementation is used when the C library doesn't define it).
156
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000157- The 'new' module is no longer an extension, but a Python module that
158 only exists for backwards compatibility. Its contents are no longer
159 functions but callable type objects.
160
Tim Peters81b92512002-04-29 01:37:32 +0000161- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000162 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000163 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000164
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000165- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
166 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000167
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000168- The locale module now exposes the C library's gettext interface.
169
Tim Petersfbf74f22002-03-14 19:06:01 +0000170- A security hole ("double free") was found in zlib-1.1.3, a popular
171 third party compression library used by some Python modules. The
172 hole was quickly plugged in zlib-1.1.4, and the Windows build of
173 Python now ships with zlib-1.1.4.
174
Martin v. Löwis688357e2002-04-08 21:28:20 +0000175- pwd, grp, and resource return enhanced tuples now, with symbolic
176 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000177
Martin v. Löwis99866332002-03-01 10:27:01 +0000178- array.array is now a type object. A new format character
179 'u' indicates Py_UNICODE arrays. For those, .tounicode and
180 .fromunicode methods are available. Arrays now support __iadd__
181 and __imul__.
182
Neal Norwitze790eae2002-01-01 21:14:12 +0000183- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000184 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
185 is called.
186
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000187- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
188 been added where available.
189
Tim Petersaf8446f2001-12-21 21:36:50 +0000190Library
191
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000192- New encoding for the Palm OS character set: palmos.
193
Tim Peters943382c2002-07-07 03:59:34 +0000194- binascii.crc32() and the zipfile module had problems on some 64-bit
195 platforms. These have been fixed. On a platform with 8-byte C longs,
196 crc32() now returns a signed-extended 4-byte result, so that its value
197 as a Python int is equal to the value computed a 32-bit platform.
198
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000199- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
200 argument.
201
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000202- Some fixes in the copy module: when an object is copied through its
203 __reduce__ method, there was no check for a __setstate__ method on
204 the result [SF patch 565085]; deepcopy should treat instances of
205 custom metaclasses the same way it treats instances of type 'type'
206 [SF patch 560794].
207
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000208- Sockets now support timeout mode. After s.settimeout(T), where T is
209 a float expressing seconds, subsequent operations raise an exception
210 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000211 mode, use s.settimeout(None). There's also a module function,
212 socket.setdefaulttimeout(T), which sets the default for all sockets
213 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000214
215- getopt.gnu_getopt was added. This supports GNU-style option
216 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000217
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000218- Stop using strings for exceptions. String objects used for
219 exceptions are now classes deriving from Exception. The objects
220 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
221 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000222
Walter Dörwald474458d2002-06-04 15:16:29 +0000223- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
224 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
225 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
226 big endian systems were added to the codecs module. The old names
227 BOM32_* and BOM64_* were off by a factor of 2.
228
Guido van Rossumf9257822002-06-18 20:43:18 +0000229- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000230
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000231- ftplib.retrlines() now tests for callback is None rather than testing
232 for False. Was causing an error when given a callback object which
233 was callable but also returned len() as zero. The change may
234 create new breakage if the caller relied on the undocumented behavior
235 and called with callback set to [] or some other False value not
236 identical to None.
237
Tim Peters46c04e12002-05-05 20:40:00 +0000238- random.gauss() uses a piece of hidden state used by nothing else,
239 and the .seed() and .whseed() methods failed to reset it. In other
240 words, setting the seed didn't completely determine the sequence of
241 results produced by random.gauss(). It does now. Programs repeatedly
242 mixing calls to a seed method with calls to gauss() may see different
243 results now.
244
Fred Drake7f781c92002-05-01 20:33:53 +0000245- The pickle.Pickler class grew a clear_memo() method to mimic that
246 provided by cPickle.Pickler.
247
Tim Peters81b92512002-04-29 01:37:32 +0000248- difflib's SequenceMatcher class now does a dynamic analysis of
249 which elements are so frequent as to constitute noise. For
250 comparing files as sequences of lines, this generally works better
251 than the IS_LINE_JUNK function, and function ndiff's linejunk
252 argument defaults to None now as a result. A happy benefit is
253 that SequenceMatcher may run much faster now when applied
254 to large files with many duplicate lines (for example, C program
255 text with lots of repeated "}" and "return NULL;" lines).
256
Guido van Rossum256705b2002-04-23 13:29:43 +0000257- New Text.dump() method in Tkinter module.
258
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000259- New distutils commands for building packagers were added to
260 support pkgtool on Solaris and swinstall on HP-UX.
261
262- distutils now has a new abstract binary packager base class
263 command/bdist_packager, which simplifies writing packagers.
264 This will hopefully provide the missing bits to encourage
265 people to submit more packagers, e.g. for Debian, FreeBSD
266 and other systems.
267
Guido van Rossumf9257822002-06-18 20:43:18 +0000268- The UTF-16, -LE and -BE stream readers now raise a
269 NotImplementedError for all calls to .readline(). Previously, they
270 used to just produce garbage or fail with an encoding error --
271 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 +0000272 work well with these.
273
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000274- compileall now supports quiet operation.
275
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000276- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000277 connections.
278
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000279- socket module: the SSL support was broken out of the main
280 _socket module C helper and placed into a new _ssl helper
281 which now gets imported by socket.py if available and working.
282
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000283- encodings package: added aliases for all supported IANA character
284 sets
285
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000286- ftplib: to safeguard the user's privacy, anonymous login will use
287 "anonymous@" as default password, rather than the real user and host
288 name.
289
Fred Drake36736122002-01-10 13:50:31 +0000290- webbrowser: tightened up the command passed to os.system() so that
291 arbitrary shell code can't be executed because a bogus URL was
292 passed in.
293
Tim Peters11bd9942002-02-01 00:52:29 +0000294- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000295 gettext.find an optional all argument. Translations will now fallback
296 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000297
Martin v. Löwis9668b932002-01-12 11:27:42 +0000298- distutils bdist commands now offer a --skip-build option.
299
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000300- warnings.warn now accepts a Warning instance as first argument.
301
Fred Drakefed7e852002-04-04 19:36:15 +0000302- The xml.sax.expatreader.ExpatParser class will no longer create
303 circular references by using itself as the locator that gets passed
304 to the content handler implementation. [SF bug #535474]
305
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000306- The email.Parser.Parser class now properly parses strings regardless
307 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
308 or CRLF). Also, the Header class's constructor default arguments
309 has changed slightly so that an explicit maxlinelen value is always
310 honored.
311
Tim Petersaf8446f2001-12-21 21:36:50 +0000312Tools/Demos
313
Marc-André Lemburg46260092002-04-04 16:17:11 +0000314- freeze.py now produces binaries which can import shared modules,
315 unlike before when this failed due to missing symbol exports in
316 the generated binary.
317
Tim Petersaf8446f2001-12-21 21:36:50 +0000318Build
319
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000320- The public Python C API will generally be declared using PyAPI_FUNC
321 and PyAPI_DATA macros, while Python extension module init functions
322 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
323 are deprecated.
324
Tim Petersc6a3ff62002-07-08 22:11:52 +0000325- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
326 get into infinite loops, when a new-style class got garbage-collected.
327 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
328 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
329 COUNT_ALLOCS is not enabled by default, in either release or debug
330 builds, and that new-style classes are immortal only in COUNT_ALLOCS
331 builds.
332
Tim Peters943382c2002-07-07 03:59:34 +0000333- Compiling out the cyclic garbage collector is no longer an option.
334 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
335 that it's always defined (for the benefit of any extension modules
336 that may be conditionalizing on it). A bonus is that any extension
337 type participating in cyclic gc can choose to participate in the
338 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
339 to require editing the core to teach the trashcan mechanism about the
340 new type.
341
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000342- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000343
344 The Standard C macro HUGE_VAL and its float and long double analogs,
345 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
346 positive infinities.
347
348 Python only uses the double HUGE_VAL, and only to #define its own symbol
349 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
350 pyport.h used to try to worm around that, but the workarounds triggered
351 other bugs on other platforms, so we gave up. If your platform defines
352 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
353 that works on your platform. The only instance of this I'm sure about
354 is on an unknown subset of Cray systems, described here:
355
356 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
357
358 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
359
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000360- The configure option --without-doc-strings can be used to remove the
361 doc strings from the builtin functions and modules; this reduces the
362 size of the executable.
363
Tim Peters639295f2002-04-21 07:30:30 +0000364- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
365 say how or when to configure it, or how to turn it off.
366
Martin v. Löwis1142de32002-03-29 16:28:31 +0000367- On Unix, a shared libpython2.3.so can be created with --enable-shared.
368
Tim Peters8deda702002-03-30 10:06:07 +0000369- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
370 preprocessor symbols were eliminated. The internal decisions they
371 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000372
Fred Drake7d28b732002-05-02 21:17:00 +0000373- The tools used to build the documentation now work under Cygwin as
374 well as Unix.
375
Skip Montanaro57454e52002-06-14 20:30:31 +0000376- The bsddb and dbm module builds have been changed to try and avoid version
377 skew problems and disable linkage with Berkeley DB 1.85 unless the
378 installer knows what s/he's doing. See the section on building these
379 modules in the README file for details.
380
Tim Petersaf8446f2001-12-21 21:36:50 +0000381C API
382
Thomas Heller085358a2002-07-29 14:27:41 +0000383- New functions PyErr_SetExcFromWindowsErr() and
384 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
385 PyErr_SetFromWindowsErrWithFilename() and
386 PyErr_SetFromWindowsErr(), but they allow to specify
387 the exception type to raise. Available on Windows.
388
Tim Peters7c321a82002-07-09 02:57:01 +0000389- Py_FatalError() is now declared as taking a const char* argument. It
390 was previously declared without const. This should not affect working
391 code.
392
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000393- Added new macro PySequence_ITEM(o, i) that directly calls
394 sq_item without rechecking that o is a sequence and without
395 adjusting for negative indices.
396
Fred Draked0ba6362002-05-02 21:28:26 +0000397- PyRange_New() now raises ValueError if the fourth argument is not 1.
398 This is part of the removal of deprecated features of the xrange
399 object.
400
Guido van Rossum517c7d42002-04-26 02:49:14 +0000401- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
402 coercion if both arguments have the same type but this type has the
403 CHECKTYPES flag set. This is to better support proxies.
404
Neil Schemenauer9344b142002-04-12 23:00:08 +0000405- The type of tp_free has been changed from "void (*)(PyObject *)" to
406 "void (*)(void *)".
407
408- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
409
Guido van Rossum0986d822002-04-08 01:38:42 +0000410- A type can now inherit its metatype from its base type. Previously,
411 when PyType_Ready() was called, if ob_type was found to be NULL, it
412 was always set to &PyType_Type; now it is set to base->ob_type,
413 where base is tp_base, defaulting to &PyObject_Type.
414
415- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
416
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000417- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000418
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000419- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000420 without going through the buffer API.
421
Martin v. Löwis7198a522002-01-01 19:59:11 +0000422- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
423
Tim Peters10a3bb52001-12-25 19:07:38 +0000424- An old #define of ANY as void has been removed from pyport.h. This
425 hasn't been used since Python's pre-ANSI days, and the #define has
426 been marked as obsolete since then. SF bug 495548 says it created
427 conflicts with other packages, so keeping it around wasn't harmless.
428
Tim Petersaf8446f2001-12-21 21:36:50 +0000429- Because Python's magic number scheme broke on January 1st, we decided
430 to stop Python development. Thanks for all the fish!
431
Tim Petersfb05db22002-03-11 00:24:00 +0000432- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000433 scheme to a new one. See Python/import.c for details.
434
Tim Petersaf8446f2001-12-21 21:36:50 +0000435New platforms
436
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000437- AtheOS is now supported.
438
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000439- GNU/Hurd is now supported.
440
Tim Petersaf8446f2001-12-21 21:36:50 +0000441Tests
442
443Windows
444
Tim Peters08e72952002-04-16 20:48:01 +0000445- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
446 of that has been fixed in the installer (disabled Wise's "delete in-
447 use files" uninstall option).
448
Guido van Rossum181e41a2002-04-06 00:23:25 +0000449- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
450
Tim Peters33187922002-04-04 20:02:04 +0000451- The installer now installs Start menu shortcuts under (the local
452 equivalent of) "All Users" when doing an Admin install.
453
Tim Petersfb05db22002-03-11 00:24:00 +0000454- file.truncate([newsize]) now works on Windows for all newsize values.
455 It used to fail if newsize didn't fit in 32 bits, reflecting a
456 limitation of MS _chsize (which is no longer used).
457
Tim Petersab034fa2002-02-01 11:27:43 +0000458- os.waitpid() is now implemented for Windows, and can be used to block
459 until a specified process exits. This is similar to, but not exactly
460 the same as, os.waitpid() on POSIX systems. If you're waiting for
461 a specific process whose pid was obtained from one of the spawn()
462 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000463 See the docs for details. The docs were changed to clarify that
464 spawn functions return, and waitpid requires, a process handle on
465 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000466
Tim Peters11bd9942002-02-01 00:52:29 +0000467- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000468 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000469 to a nasty problem: before 2.3, if you got a temp file on Windows, it
470 got wrapped in an object whose close() method first closed the
471 underlying file, then deleted the file. This usually worked fine.
472 However, the spawn family of functions on Windows create (at a low C
473 level) the same set of open files in the spawned process Q as were
474 open in the spawning process P. If a temp file f was among them, then
475 doing f.close() in P first closed P's C-level file handle on f, but Q's
476 C-level file handle on f remained open, so the attempt in P to delete f
477 blew up with a "Permission denied" error (Windows doesn't allow
478 deleting open files). This was surprising, subtle, and difficult to
479 work around.
480
481- The os module now exports all the symbolic constants usable with the
482 low-level os.open() on Windows: the new constants in 2.3 are
483 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
484 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
485 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
486 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
487 (so specify both if you want both; note that neither is useful unless
488 specified with O_CREAT too).
489
Tim Petersaf8446f2001-12-21 21:36:50 +0000490Mac
491
492
Tim Peters909c0912001-12-14 23:16:18 +0000493What's New in Python 2.2 final?
494Release date: 21-Dec-2001
495===============================
496
497Type/class unification and new-style classes
498
Barry Warsaw52acb492001-12-21 20:04:22 +0000499- pickle.py, cPickle: allow pickling instances of new-style classes
500 with a custom metaclass.
501
Tim Peters909c0912001-12-14 23:16:18 +0000502Core and builtins
503
Barry Warsaw52acb492001-12-21 20:04:22 +0000504- weakref proxy object: when comparing, unwrap both arguments if both
505 are proxies.
506
Tim Peters909c0912001-12-14 23:16:18 +0000507Extension modules
508
Barry Warsaw52acb492001-12-21 20:04:22 +0000509- binascii.b2a_base64(): fix a potential buffer overrun when encoding
510 very short strings.
511
512- cPickle: the obscure "fast" mode was suspected of causing stack
513 overflows on the Mac. Hopefully fixed this by setting the recursion
514 limit much smaller. If the limit is too low (it only affects
515 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
516 when compiling cPickle.c (or in pyconfig.h).
517
Tim Peters909c0912001-12-14 23:16:18 +0000518Library
519
Barry Warsaw52acb492001-12-21 20:04:22 +0000520- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
521 close or delete time).
522
523- rfc822.py: fixed a bug where the address '<>' was converted to None
524 instead of an empty string (also fixes the email.Utils module).
525
526- xmlrpclib.py: version 1.0.0; uses precision for doubles.
527
528- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000529 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000530
Tim Peters909c0912001-12-14 23:16:18 +0000531Tools/Demos
532
533Build
534
535C API
536
537New platforms
538
539Tests
540
541Windows
542
Barry Warsaw52acb492001-12-21 20:04:22 +0000543- distutils package: fixed broken Windows installers (bdist_wininst).
544
545- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
546 instances are deleted at process exit time.
547
548- socket.py: prevent mysterious warnings when socket instances are
549 deleted at process exit time.
550
551- posixmodule.c: fix a Windows crash with stat() of a filename ending
552 in backslash.
553
Tim Peters909c0912001-12-14 23:16:18 +0000554Mac
555
Barry Warsaw52acb492001-12-21 20:04:22 +0000556- The Carbon toolbox modules have been upgraded to Universal Headers
557 3.4, and experimental CoreGraphics and CarbonEvents modules have
558 been added. All only for framework-enabled MacOSX.
559
Tim Peters909c0912001-12-14 23:16:18 +0000560
Tim Peters6272dfd2001-12-13 19:34:00 +0000561What's New in Python 2.2c1?
562Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000563===========================
564
565Type/class unification and new-style classes
566
Barry Warsaw06557452001-12-14 20:47:12 +0000567- Guido's tutorial introduction to the new type/class features has
568 been extensively updated. See
569
570 http://www.python.org/2.2/descrintro.html
571
572 That remains the primary documentation in this area.
573
Guido van Rossum33bab012001-12-05 22:45:48 +0000574- Fixed a leak: instance variables declared with __slots__ were never
575 deleted!
576
Guido van Rossum4b800852001-12-03 00:54:52 +0000577- The "delete attribute" method of descriptor objects is called
578 __delete__, not __del__. In previous releases, it was mistakenly
579 called __del__, which created an unfortunate overloading condition
580 with finalizers. (The "get attribute" and "set attribute" methods
581 are still called __get__ and __set__, respectively.)
582
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000583- Some subtle issues with the super built-in were fixed:
584
585 (a) When super itself is subclassed, its __get__ method would still
586 return an instance of the base class (i.e., of super).
587
588 (b) super(C, C()).__class__ would return C rather than super. This
589 is confusing. To fix this, I decided to change the semantics of
590 super so that it only applies to code attributes, not to data
591 attributes. After all, overriding data attributes is not
592 supported anyway.
593
594 (c) The __get__ method didn't check whether the argument was an
595 instance of the type used in creation of the super instance.
596
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000597- Previously, hash() of an instance of a subclass of a mutable type
598 (list or dictionary) would return some value, rather than raising
599 TypeError. This has been fixed. Also, directly calling
600 dict.__hash__ and list.__hash__ now raises the same TypeError
601 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000602
Guido van Rossumd331cb52001-12-05 19:46:42 +0000603- New-style objects now support deleting their __dict__. This is for
604 all intents and purposes equivalent to assigning a brand new empty
605 dictionary, but saves space if the object is not used further.
606
Tim Petersb3c9af12001-11-17 00:21:57 +0000607Core and builtins
608
Tim Peters3caca232001-12-06 06:23:26 +0000609- -Qnew now works as documented in PEP 238: when -Qnew is passed on
610 the command line, all occurrences of "/" use true division instead
611 of classic division. See the PEP for details. Note that "all"
612 means all instances in library and 3rd-party modules, as well as in
613 your own code. As the PEP says, -Qnew is intended for use only in
614 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000615 Note that test_coercion.py in the standard Python test suite fails
616 under -Qnew; this is expected, and won't be repaired until true
617 division becomes the default (in the meantime, test_coercion is
618 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000619
Fred Drake6c01e252001-12-14 17:08:12 +0000620- complex() now only allows the first argument to be a string
621 argument, and raises TypeError if either the second arg is a string
622 or if the second arg is specified when the first is a string.
623
Tim Petersb3c9af12001-11-17 00:21:57 +0000624Extension modules
625
Martin v. Löwis560da622001-11-24 09:24:51 +0000626- gc.get_referents was renamed to gc.get_referrers.
627
Tim Petersb3c9af12001-11-17 00:21:57 +0000628Library
629
Tim Peters25059d32001-12-07 20:35:43 +0000630- Functions in the os.spawn() family now release the global interpreter
631 lock around calling the platform spawn. They should always have done
632 this, but did not before 2.2c1. Multithreaded programs calling
633 an os.spawn function with P_WAIT will no longer block all Python threads
634 until the spawned program completes. It's possible that some programs
635 relies on blocking, although more likely by accident than by design.
636
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000637- webbrowser defaults to netscape.exe on OS/2 now.
638
Martin v. Löwis652e1912001-11-25 14:50:56 +0000639- Tix.ResizeHandle exposes detach_widget, hide, and show.
640
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000641- The charset alias windows_1252 has been added.
642
Barry Warsaw06557452001-12-14 20:47:12 +0000643- types.StringTypes is a tuple containing the defined string types;
644 usually this will be (str, unicode), but if Python was compiled
645 without Unicode support it will be just (str,).
646
647- The pulldom and minidom modules were synchronized to PyXML.
648
Tim Petersb3c9af12001-11-17 00:21:57 +0000649Tools/Demos
650
Barry Warsaw06557452001-12-14 20:47:12 +0000651- A new script called Tools/scripts/google.py was added, which fires
652 off a search on Google.
653
Tim Petersb3c9af12001-11-17 00:21:57 +0000654Build
655
Barry Warsaw06557452001-12-14 20:47:12 +0000656- Note that release builds of Python should arrange to define the
657 preprocessor symbol NDEBUG on the command line (or equivalent).
658 In the 2.2 pre-release series we tried to define this by magic in
659 Python.h instead, but it proved to cause problems for extension
660 authors. The Unix, Windows and Mac builds now all define NDEBUG in
661 release builds via cmdline (or equivalent) instead. Ports to
662 other platforms should do likewise.
663
Jack Jansen1999ef42001-12-06 21:47:20 +0000664- It is no longer necessary to use --with-suffix when building on a
665 case-insensitive file system (such as Mac OS X HFS+). In the build
666 directory an extension is used, but not in the installed python.
667
Tim Petersb3c9af12001-11-17 00:21:57 +0000668C API
669
Tim Petersf582b822001-12-11 18:51:08 +0000670- New function PyDict_MergeFromSeq2() exposes the builtin dict
671 constructor's logic for updating a dictionary from an iterable object
672 producing key-value pairs.
673
Tim Peterscffed4b2001-11-29 03:26:37 +0000674- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000675 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000676 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
677 dump core in some bad cases. This has been repaired. As a result,
678 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
679 previously went unchallenged.
680
Tim Petersb3c9af12001-11-17 00:21:57 +0000681New platforms
682
683Tests
684
685Windows
686
687Mac
688
Jack Jansenffa260f2001-12-06 21:14:00 +0000689- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
690 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000691
Barry Warsaw06557452001-12-14 20:47:12 +0000692- Changed logic for finding python home in Mac OS X framework Pythons.
693 Now sys.executable points to the executable again, in stead of to
694 the shared library. The latter is used only for locating the python
695 home.
696
697
Tim Peters84362bc2001-10-19 17:55:30 +0000698What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000699Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000700===========================
701
702Type/class unification and new-style classes
703
Guido van Rossum3d27df02001-11-15 20:27:54 +0000704- Multiple inheritance mixing new-style and classic classes in the
705 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000706
707 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000708 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000709
710 The MRO (method resolution order) for each base class is respected
711 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000712 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000713 This needs to be documented.
714
Tim Petersa427a2b2001-10-29 22:25:45 +0000715- The new builtin dictionary() constructor, and dictionary type, have
716 been renamed to dict. This reflects a decade of common usage.
717
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000718- dict() now accepts an iterable object producing 2-sequences. For
719 example, dict(d.items()) == d for any dictionary d. The argument,
720 and the elements of the argument, can be any iterable objects.
721
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000722- New-style classes can now have a __del__ method, which is called
723 when the instance is deleted (just like for classic classes).
724
Guido van Rossum12d955c2001-10-26 14:56:06 +0000725- Assignment to object.__dict__ is now possible, for objects that are
726 instances of new-style classes that have a __dict__ (unless the base
727 class forbids it).
728
Guido van Rossumc8e56452001-10-22 00:43:43 +0000729- Methods of built-in types now properly check for keyword arguments
730 (formerly these were silently ignored). The only built-in methods
731 that take keyword arguments are __call__, __init__ and __new__.
732
Guido van Rossum86443212001-10-27 22:28:54 +0000733- The socket function has been converted to a type; see below.
734
Tim Peters84362bc2001-10-19 17:55:30 +0000735Core and builtins
736
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000737- Assignment to __debug__ raises SyntaxError at compile-time. This
738 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000739 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000740
Guido van Rossum12d955c2001-10-26 14:56:06 +0000741- Clarified the error messages for unsupported operands to an operator
742 (like 1 + '').
743
Tim Peters84362bc2001-10-19 17:55:30 +0000744Extension modules
745
Tim Peters5ebfd362001-11-13 23:11:19 +0000746- mmap has a new keyword argument, "access", allowing a uniform way for
747 both Windows and Unix users to create read-only, write-through and
748 copy-on-write memory mappings. This was previously possible only on
749 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000750 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000751 platforms. Thanks to Jay T Miller for repairing this!
752
Tim Peters169ded02001-11-03 19:57:21 +0000753- By default, the gc.garbage list now contains only those instances in
754 unreachable cycles that have __del__ methods; in 2.1 it contained all
755 instances in unreachable cycles. "Instances" here has been generalized
756 to include instances of both new-style and old-style classes.
757
Guido van Rossum12d955c2001-10-26 14:56:06 +0000758- The socket module defines a new method for socket objects,
759 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000760 send() until all data has been sent. Also, the socket function has
761 been converted to a subclassable type, like list and tuple (etc.)
762 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000763
764- Various bugfixes to the curses module. There is now a test suite
765 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000766
Guido van Rossum692adf12001-10-30 03:03:03 +0000767- binascii.b2a_base64 no longer places an arbitrary restriction of 57
768 bytes on its input.
769
Tim Peters84362bc2001-10-19 17:55:30 +0000770Library
771
Tim Peters5ebfd362001-11-13 23:11:19 +0000772- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000773 convenience function.
774
Tim Peters75335872001-11-03 19:35:43 +0000775- Symbolic group names in regular expressions must be unique. For
776 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
777 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000778 Python 2.2 detects this error at regexp compilation time;
779 previously, the error went undetected, and results were
780 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
781 pattern.subn() methods have been rewritten in C. Also, an
782 experimental function/method finditer() has been added, which works
783 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000784
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000785- Tix exposes more commands through the classes DirSelectBox,
786 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
787 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
788 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
789
Tim Peters98791af2001-10-23 01:59:54 +0000790- Traceback objects are now scanned by cyclic garbage collection, so
791 cycles created by casual use of sys.exc_info() no longer cause
792 permanent memory leaks (provided garbage collection is enabled).
793
Guido van Rossum49192142001-10-24 20:51:44 +0000794- os.extsep -- a new variable needed by the RISCOS support. It is the
795 separator used by extensions, and is '.' on all platforms except
796 RISCOS, where it is '/'. There is no need to use this variable
797 unless you have a masochistic desire to port your code to RISCOS.
798
Barry Warsaw012852b2001-11-16 16:17:27 +0000799- mimetypes.py has optional support for non-standard, but commonly
800 found types. guess_type() and guess_extension() now accept an
801 optional `strict' flag, defaulting to true, which controls whether
802 recognize non-standard types or not. A few non-standard types we
803 know about have been added. Also, when run as a script, there are
804 new -l and -e options.
805
806- statcache is now deprecated.
807
808- email.Utils.formatdate() now produces the preferred RFC 2822 style
809 dates with numeric timezones (it used to produce obsolete dates
810 hard coded to "GMT" timezone). An optional `localtime' flag is
811 added to produce dates in the local timezone, with daylight savings
812 time properly taken into account.
813
814- In pickle and cPickle, instead of masking errors in load() by
815 transforming them into SystemError, we let the original exception
816 propagate out. Also, implement support for __safe_for_unpickling__
817 in pickle, as it already was supported in cPickle.
818
Tim Peters84362bc2001-10-19 17:55:30 +0000819Tools/Demos
820
821Build
822
Barry Warsaw012852b2001-11-16 16:17:27 +0000823- The dbm module is built using libdb1 if available. The bsddb module
824 is built with libdb3 if available.
825
826- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
827
Tim Peters84362bc2001-10-19 17:55:30 +0000828C API
829
Tim Peters1fc240e2001-10-26 05:06:50 +0000830- New function PySequence_Fast_GET_SIZE() returns the size of a non-
831 NULL result from PySequence_Fast(), more quickly than calling
832 PySequence_Size().
833
Barry Warsaw012852b2001-11-16 16:17:27 +0000834- New argument unpacking function PyArg_UnpackTuple() added.
835
836- New functions PyObject_CallFunctionObjArgs() and
837 PyObject_CallMethodObjArgs() have been added to make it more
838 convenient and efficient to call functions and methods from C.
839
840- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
841 possible that this will propagate errors it didn't before.
842
843- New function PyObject_CheckReadBuffer(), which returns true if its
844 argument supports the single-segment readable buffer interface.
845
Tim Peters84362bc2001-10-19 17:55:30 +0000846New platforms
847
Guido van Rossum86443212001-10-27 22:28:54 +0000848- We've finally confirmed that this release builds on HP-UX 11.00,
849 *with* threads, and passes the test suite.
850
Tim Peters7a33d8b2001-11-05 02:51:07 +0000851- Thanks to a series of patches from Michael Muller, Python may build
852 again under OS/2 Visual Age C++.
853
Guido van Rossum49192142001-10-24 20:51:44 +0000854- Updated RISCOS port by Dietmar Schwertberger.
855
Tim Peters84362bc2001-10-19 17:55:30 +0000856Tests
857
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000858- Added a test script for the curses module. It isn't run automatically;
859 regrtest.py must be run with '-u curses' to enable it.
860
Tim Peters84362bc2001-10-19 17:55:30 +0000861Windows
862
Barry Warsaw012852b2001-11-16 16:17:27 +0000863Mac
864
865- PythonScript has been moved to unsupported and is slated to be
866 removed completely in the next release.
867
868- It should now be possible to build applets that work on both OS9 and
869 OSX.
870
871- The core is now linked with CoreServices not Carbon; as a side
872 result, default 8bit encoding on OSX is now ASCII.
873
874- Python should now build on OSX 10.1.1
875
Tim Peters84362bc2001-10-19 17:55:30 +0000876
Tim Petersabf925f2001-09-28 21:53:42 +0000877What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000878Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000879===========================
880
881Type/class unification and new-style classes
882
Guido van Rossum687ae002001-10-15 22:03:32 +0000883- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000884 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000885 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000886 remains: the __dict__ of a new-style class is a read-only proxy; you
887 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000888 __defined__ attribute of new-style types no longer exists, for lack
889 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000890 future a __cache__ may be resurrected with a similar function, if I
891 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000892
Tim Peters1c9ca872001-10-04 06:43:12 +0000893- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
894 always returned None, even when there was a class docstring).
895
896- doctest now finds and runs docstrings attached to new-style classes,
897 class methods, static methods, and properties.
898
Guido van Rossum9074ef62001-10-16 21:34:49 +0000899Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000900
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000901- A very subtle syntactical pitfall in list comprehensions was fixed.
902 For example: [a+b for a in 'abc', for b in 'def']. The comma in
903 this example is a mistake. Previously, this would silently let 'a'
904 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
905 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
906 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
907 Note that [a for a in <singleton>] is a convoluted way to say
908 [<singleton>] anyway, so it's not like any expressiveness is lost.
909
Guido van Rossum9074ef62001-10-16 21:34:49 +0000910- getattr(obj, name, default) now only catches AttributeError, as
911 documented, rather than returning the default value for all
912 exceptions (which could mask bugs in a __getattr__ hook, for
913 example).
914
Fred Drakecb7a6b52001-10-22 18:41:51 +0000915- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000916 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000917 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000918 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000919
Guido van Rossum1c486092001-10-19 02:05:35 +0000920- unicode(obj) now behaves more like str(obj), accepting arbitrary
921 objects, and calling a __unicode__ method if it exists.
922 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000923 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000924
Barry Warsawf6fb1712001-10-19 05:35:40 +0000925- isinstance() now allows any object as the first argument and a
926 class, a type or something with a __bases__ tuple attribute for the
927 second argument. The second argument may also be a tuple of a
928 class, type, or something with __bases__, in which case isinstance()
929 will return true if the first argument is an instance of any of the
930 things contained in the second argument tuple. E.g.
931
932 isinstance(x, (A, B))
933
934 returns true if x is an instance of A or B.
935
Guido van Rossum9074ef62001-10-16 21:34:49 +0000936Extension modules
937
938- thread.start_new_thread() now returns the thread ID (previously None).
939
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000940- binascii has now two quopri support functions, a2b_qp and b2a_qp.
941
Guido van Rossumc524d952001-10-19 01:31:59 +0000942- readline now supports setting the startup_hook and the
943 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000944
Guido van Rossumc524d952001-10-19 01:31:59 +0000945- os and posix supports chroot(), setgroups() and unsetenv() where
946 available. The stat(), fstat(), statvfs() and fstatvfs() functions
947 now return "pseudo-sequences" -- the various fields can now be
948 accessed as attributes (e.g. os.stat("/").st_mtime) but for
949 backwards compatibility they also behave as a fixed-length sequence.
950 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000951 attributes.
952
953- time: localtime(), gmtime() and strptime() now return a
954 pseudo-sequence similar to the os.stat() return value, with
955 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000956
Guido van Rossum9074ef62001-10-16 21:34:49 +0000957- Decompression objects in the zlib module now accept an optional
958 second parameter to decompress() that specifies the maximum amount
959 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000960
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000961- optional SSL support in the socket module now exports OpenSSL
962 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
963 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000964 automatically seed its PRNG. Also, the keyfile and certfile
965 arguments to socket.ssl() are now optional.
966
967- posixmodule (and by extension, the os module on POSIX platforms) now
968 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000969
Guido van Rossum9074ef62001-10-16 21:34:49 +0000970Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000971
Tim Peters7402f792001-10-02 03:53:41 +0000972- doctest now excludes functions and classes not defined by the module
973 being tested, thanks to Tim Hochberg.
974
Fred Drakecb7a6b52001-10-22 18:41:51 +0000975- HotShot, a new profiler implemented using a C-based callback, has
976 been added. This substantially reduces the overhead of profiling,
977 but it is still quite preliminary. Support modules and
978 documentation will be added in upcoming releases (before 2.2 final).
979
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000980- profile now produces correct output in situations where an exception
981 raised in Python is cleared by C code (e.g. hasattr()). This used
982 to cause wrong output, including spurious claims of recursive
983 functions and attribution of time spent to the wrong function.
984
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000985 The code and documentation for the derived OldProfile and HotProfile
986 profiling classes was removed. The code hasn't worked for years (if
987 you tried to use them, they raised exceptions). OldProfile
988 intended to reproduce the behavior of the profiler Python used more
989 than 7 years ago, and isn't interesting anymore. HotProfile intended
990 to provide a faster profiler (but producing less information), and
991 that's a worthy goal we intend to meet via a different approach (but
992 without losing information).
993
Tim Peterscce092d2001-10-09 05:31:56 +0000994- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000995 a much better system-specific calibration constant. The constant can
996 now be specified in an instance constructor, or as a Profile class or
997 instance variable, instead of by editing profile.py's source code.
998 Calibration must still be done manually (see the docs for the profile
999 module).
1000
1001 Note that Profile.calibrate() must be overriden by subclasses.
1002 Improving the accuracy required exploiting detailed knowledge of
1003 profiler internals; the earlier method abstracted away the details
1004 and measured a simplified model instead, but consequently computed
1005 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001006
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001007- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001008 which indicates whether output is intended for the header 'Q'
1009 encoding.
1010
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001011- The SocketServer.ThreadingMixIn class now closes the request after
1012 finish_request() returns. (Not when it errors out though.)
1013
Barry Warsawf6fb1712001-10-19 05:35:40 +00001014- The nntplib module's NNTP.body() method has grown a `file' argument
1015 to allow saving the message body to a file.
1016
1017- The email package has added a class email.Parser.HeaderParser which
1018 only parses headers and does not recurse into the message's body.
1019 Also, the module/class MIMEAudio has been added for representing
1020 audio data (contributed by Anthony Baxter).
1021
1022- ftplib should be able to handle files > 2GB.
1023
1024- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1025 ON, and OFF.
1026
Fred Drakecb7a6b52001-10-22 18:41:51 +00001027- xml.dom.minidom NodeList objects now support the length attribute
1028 and item() method as required by the DOM specifications.
1029
Guido van Rossumed554f62001-10-02 23:15:37 +00001030Tools/Demos
1031
1032- Demo/dns was removed. It no longer serves any purpose; a package
1033 derived from it is now maintained by Anthony Baxter, see
1034 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001035
Barry Warsawf6fb1712001-10-19 05:35:40 +00001036- The freeze tool has been made more robust, and two new options have
1037 been added: -X and -E.
1038
Tim Petersabf925f2001-09-28 21:53:42 +00001039Build
1040
Barry Warsawf6fb1712001-10-19 05:35:40 +00001041- configure will use CXX in LINKCC if CXX is used to build main() and
1042 the system requires to link a C++ main using the C++ compiler.
1043
Tim Petersabf925f2001-09-28 21:53:42 +00001044C API
1045
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001046- The documentation for the tp_compare slot is updated to require that
1047 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1048 not correct. This is not yet enforced but will be enforced in
1049 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1050 "NotImplemented". Right now, -1 should be used for an error return.
1051
Tim Petersd38b1c72001-09-30 05:09:37 +00001052- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1053 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1054 as long) arguments.
1055
Guido van Rossum3c288632001-10-16 21:13:49 +00001056- PyThread_start_new_thread() now returns a long int giving the thread
1057 ID, if one can be calculated; it returns -1 for error, 0 if no
1058 thread ID is calculated (this is an incompatible change, but only
1059 the thread module used this API). This code has only really been
1060 tested on Linux and Windows; other platforms please beware (and
1061 report any bugs or strange behavior).
1062
Guido van Rossum1c486092001-10-19 02:05:35 +00001063- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1064 input.
1065
Tim Petersabf925f2001-09-28 21:53:42 +00001066New platforms
1067
1068Tests
1069
1070Windows
1071
Tim Peters04cf1d32001-10-09 22:39:40 +00001072- Installer: If you install IDLE, and don't disable file-extension
1073 registration, a new "Edit with IDLE" context (right-click) menu entry
1074 is created for .py and .pyw files.
1075
Tim Peters1ce3cf72001-10-01 17:58:40 +00001076- The signal module now supports SIGBREAK on Windows, thanks to Steven
1077 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1078 action remains to call Win32 ExitProcess(). This can be changed via
1079 signal.signal(). For example:
1080
1081 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1082 # (SIGINT) behavior.
1083 import signal
1084 signal.signal(signal.SIGBREAK,
1085 signal.default_int_handler)
1086
1087 try:
1088 while 1:
1089 pass
1090 except KeyboardInterrupt:
1091 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1092 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1093 # program without the possibility for any Python-level cleanup).
1094 print "Clean exit"
1095
Tim Petersabf925f2001-09-28 21:53:42 +00001096
Tim Petersb07352e2001-09-08 01:25:47 +00001097What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001098Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001099===========================
1100
Guido van Rossum808eea72001-09-25 04:15:41 +00001101Type/class unification and new-style classes
1102
1103- pydoc and inspect are now aware of new-style classes;
1104 e.g. help(list) at the interactive prompt now shows proper
1105 documentation for all operations on list objects.
1106
1107- Applications using Jim Fulton's ExtensionClass module can now safely
1108 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1109 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1110 examples also work again. It is hoped that Gtk and Boost also work
1111 with 2.2a4 and beyond. (If you can confirm this, please write
1112 webmaster@python.org; if there are still problems, please open a bug
1113 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001114
Tim Peters66c1a522001-09-24 21:17:50 +00001115- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001116 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001117 in the constructed property object. fget, fset and fdel weren't
1118 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1119 associate a docstring with a property.
1120
Guido van Rossum808eea72001-09-25 04:15:41 +00001121- Comparison overloading is now more completely implemented. For
1122 example, a str subclass instance can properly be compared to a str
1123 instance, and it can properly overload comparison. Ditto for most
1124 other built-in object types.
1125
1126- The repr() of new-style classes has changed; instead of <type
1127 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1128 *except* for built-in types, which are still rendered as <type
1129 'Foo'> (to avoid upsetting existing code that might parse or
1130 otherwise rely on repr() of certain type objects).
1131
1132- The repr() of new-style objects is now always <Foo object at XXX>;
1133 previously, it was sometimes <Foo instance at XXX>.
1134
1135- For new-style classes, what was previously called __getattr__ is now
1136 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001137 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001138 one in classic classes is defined which is called only if regular
1139 attribute access raises AttributeError; to catch *all* attribute
1140 access, you can use __getattribute__ (for new-style classes). If
1141 both are defined, __getattribute__ is called first, and if it raises
1142 AttributeError, __getattr__ is called.
1143
1144- The __class__ attribute of new-style objects can be assigned to.
1145 The new class must have the same C-level object layout as the old
1146 class.
1147
1148- The builtin file type can be subclassed now. In the usual pattern,
1149 "file" is the name of the builtin type, and file() is a new builtin
1150 constructor, with the same signature as the builtin open() function.
1151 file() is now the preferred way to open a file.
1152
1153- Previously, __new__ would only see sequential arguments passed to
1154 the type in a constructor call; __init__ would see both sequential
1155 and keyword arguments. This made no sense whatsoever any more, so
1156 now both __new__ and __init__ see all arguments.
1157
1158- Previously, hash() applied to an instance of a subclass of str or
1159 unicode always returned 0. This has been repaired.
1160
1161- Previously, an operation on an instance of a subclass of an
1162 immutable type (int, long, float, complex, tuple, str, unicode),
1163 where the subtype didn't override the operation (and so the
1164 operation was handled by the builtin type), could return that
1165 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001166 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001167 with the same value as s.
1168
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001169- Provisional support for pickling new-style objects has been added.
1170
Guido van Rossum808eea72001-09-25 04:15:41 +00001171Core
1172
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001173- file.writelines() now accepts any iterable object producing strings.
1174
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001175- PyUnicode_FromEncodedObject() now works very much like
1176 PyObject_Str(obj) in that it tries to use __str__/tp_str
1177 on the object if the object is not a string or buffer. This
1178 makes unicode() behave like str() when applied to non-string/buffer
1179 objects.
1180
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001181- PyFile_WriteObject now passes Unicode objects to the file's write
1182 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001183 of a print statement must support Unicode objects, i.e. they must
1184 at least convert them into ASCII strings.
1185
Guido van Rossum624c8af2001-09-18 15:21:04 +00001186- Thread scheduling on Solaris should be improved; it is no longer
1187 necessary to insert a small sleep at the start of a thread in order
1188 to let other runnable threads be scheduled.
1189
Tim Petersb07352e2001-09-08 01:25:47 +00001190Library
1191
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001192- StringIO.StringIO instances and cStringIO.StringIO instances support
1193 read character buffer compatible objects for their .write() methods.
1194 These objects are converted to strings and then handled as such
1195 by the instances.
1196
Barry Warsaw2f600732001-09-24 04:28:10 +00001197- The "email" package has been added. This is basically a port of the
1198 mimelib package <http://sf.net/projects/mimelib> with API changes
1199 and some implementations updated to use iterators and generators.
1200
Tim Peters8a9c2842001-09-22 21:30:22 +00001201- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1202 restores the ability of Tools/scripts/ndiff.py to start producing output
1203 before the entire comparison is complete.
1204
Barry Warsaw58b072d2001-09-22 04:44:21 +00001205- StringIO.StringIO instances and cStringIO.StringIO instances support
1206 iteration just like file objects (i.e. their .readline() method is
1207 called for each iteration until it returns an empty string).
1208
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001209- The codecs module has grown four new helper APIs to access
1210 builtin codecs: getencoder(), getdecoder(), getreader(),
1211 getwriter().
1212
Guido van Rossum624c8af2001-09-18 15:21:04 +00001213- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1214 simplifies writing XML RPC servers.
1215
Barry Warsaw647d5e82001-09-28 17:01:02 +00001216- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001217 after interpretation of symbolic links. On non-Unix systems, this
1218 is an alias for os.path.abspath().
1219
Tim Peters16a77ad2001-09-08 04:00:12 +00001220- operator.indexOf() (PySequence_Index() in the C API) now works with any
1221 iterable object.
1222
Guido van Rossum624c8af2001-09-18 15:21:04 +00001223- smtplib now supports various authentication and security features of
1224 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001225
Guido van Rossum624c8af2001-09-18 15:21:04 +00001226- hmac: a new module implementing keyed hashing for message
1227 authentication.
1228
1229- mimetypes now recognizes more extensions and file types. At the
1230 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001231
Guido van Rossum624c8af2001-09-18 15:21:04 +00001232- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001233 Python 2.2 bytecode generation. It has also been promoted from a
1234 Tool to a standard library package. (Tools/compiler still exists as
1235 a sample driver.)
1236
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001237Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001238
Tim Petersb07352e2001-09-08 01:25:47 +00001239Build
1240
Guido van Rossum624c8af2001-09-18 15:21:04 +00001241- Large file support (LFS) is now automatic when the platform supports
1242 it; no more manual configuration tweaks are needed. On Linux, at
1243 least, it's possible to have a system whose C library supports large
1244 files but whose kernel doesn't; in this case, large file support is
1245 still enabled but doesn't do you any good unless you upgrade your
1246 kernel or share your Python executable with another system whose
1247 kernel has large file support.
1248
1249- The configure script now supplies plausible defaults in a
1250 cross-compilation environment. This doesn't mean that the supplied
1251 values are always correct, or that cross-compilation now works
1252 flawlessly -- but it's a first step (and it shuts up most of
1253 autoconf's warnings about AC_TRY_RUN).
1254
1255- The Unix build is now a bit less chatty, courtesy of the parser
1256 generator. The build is completely silent (except for errors) when
1257 using "make -s", thanks to a -q option to setup.py.
1258
Tim Petersb07352e2001-09-08 01:25:47 +00001259C API
1260
Guido van Rossum624c8af2001-09-18 15:21:04 +00001261- The "structmember" API now supports some new flag bits to deny read
1262 and/or write access to attributes in restricted execution mode.
1263
Tim Petersb07352e2001-09-08 01:25:47 +00001264New platforms
1265
Guido van Rossum624c8af2001-09-18 15:21:04 +00001266- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1267 (http://familiar.handhelds.org).
1268
Tim Petersb07352e2001-09-08 01:25:47 +00001269Tests
1270
Tim Peters8a9c2842001-09-22 21:30:22 +00001271- The "classic" standard tests, which work by comparing stdout to
1272 an expected-output file under Lib/test/output/, no longer stop at
1273 the first mismatch. Instead the test is run to completion, and a
1274 variant of ndiff-style comparison is used to report all differences.
1275 This is much easier to understand than the previous style of reporting.
1276
1277- The unittest-based standard tests now use regrtest's test_main()
1278 convention, instead of running as a side-effect of merely being
1279 imported. This allows these tests to be run in more natural and
1280 flexible ways as unittests, outside the regrtest framework.
1281
1282- regrtest.py is much better integrated with unittest and doctest now,
1283 especially in regard to reporting errors.
1284
Tim Petersb07352e2001-09-08 01:25:47 +00001285Windows
1286
Guido van Rossum624c8af2001-09-18 15:21:04 +00001287- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001288 that support it (NTFS under Windows 2000). See "What's New in
1289 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001290
Tim Petersb07352e2001-09-08 01:25:47 +00001291
Tim Petersedc99312001-08-22 21:36:50 +00001292What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001293Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001294===========================
1295
1296Core
1297
Tim Peters9fffa3e2001-09-04 05:14:19 +00001298- Conversion of long to float now raises OverflowError if the long is too
1299 big to represent as a C double.
1300
Tim Peters32f453e2001-09-03 08:35:41 +00001301- The 3-argument builtin pow() no longer allows a third non-None argument
1302 if either of the first two arguments is a float, or if both are of
1303 integer types and the second argument is negative (in which latter case
1304 the arguments are converted to float, so this is really the same
1305 restriction).
1306
Tim Peters5d2b77c2001-09-03 05:47:38 +00001307- The builtin dir() now returns more information, and sometimes much
1308 more, generally naming all attributes of an object, and all attributes
1309 reachable from the object via its class, and from its class's base
1310 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1311 an empty list. In 2.2a3,
1312
1313 >>> dir([])
1314 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1315 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1316 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1317 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1318 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1319 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1320 'reverse', 'sort']
1321
1322 dir(module) continues to return only the module's attributes, though.
1323
Tim Petersbdee63f2001-09-02 03:40:59 +00001324- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001325 than raising OverflowError. This is a partial implementation of PEP
1326 237. You can use -Wdefault::OverflowWarning to enable a warning for
1327 this situation, and -Werror::OverflowWarning to revert to the old
1328 OverflowError exception.
1329
Guido van Rossum61c345f2001-09-04 03:26:15 +00001330- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001331 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001332 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1333 -Qold, meaning the / operator has its classic meaning and no
1334 warnings are issued. Using -Qwarn issues a run-time warning about
1335 all uses of classic division for int and long arguments; -Qwarnall
1336 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001337 (for use with fixdiv.py).
1338 [Note: the remainder of this paragraph (preserved below) became
1339 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1340 <obsolete>
1341 Using -Qnew is questionable; it turns on new division by default, but
1342 only in the __main__ module. You can usefully combine -Qwarn or
1343 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1344 warns about classic division everywhere else.
1345 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001346
Tim Petersbdee63f2001-09-02 03:40:59 +00001347- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001348 long, float, str, unicode, and tuple. (The types complex, list and
1349 dictionary can also be subclassed; this was introduced earlier.)
1350 Note that restrictions apply when subclassing immutable built-in
1351 types: you can only affect the value of the instance by overloading
1352 __new__. You can add mutable attributes, and the subclass instances
1353 will have a __dict__ attribute, but you cannot change the "value"
1354 (as implemented by the base class) of an immutable subclass instance
1355 once it is created.
1356
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001357- The dictionary constructor now takes an optional argument, a
1358 mapping-like object, and initializes the dictionary from its
1359 (key, value) pairs.
1360
Tim Petersbdee63f2001-09-02 03:40:59 +00001361- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001362 "cooperative super calls" in a multiple inheritance setting. For an
1363 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1364
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001365- A new built-in type, property, has been added. This enables the
1366 creation of "properties". These are attributes implemented by
1367 getter and setter functions (or only one of these for read-only or
1368 write-only attributes), without the need to override __getattr__.
1369 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001370
Tim Petersbdee63f2001-09-02 03:40:59 +00001371- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001372 liberalized, to allow leading zeroes. Examples of literals now
1373 legal that were SyntaxErrors before:
1374
1375 00.0 0e3 0100j 07.5 00000000000000000008.
1376
Tim Petersbdee63f2001-09-02 03:40:59 +00001377- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001378 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1379
Tim Petersedc99312001-08-22 21:36:50 +00001380Library
1381
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001382- telnetlib includes symbolic names for the options, and support for
1383 setting an option negotiation callback.
1384
Tim Petersa40c7932001-09-05 22:36:56 +00001385- The new C standard no longer requires that math libraries set errno to
1386 ERANGE on overflow. For platform libraries that exploit this new
1387 freedom, Python's overflow-checking was wholly broken. A new overflow-
1388 checking scheme attempts to repair that, but may not be reliable on all
1389 platforms (C doesn't seem to provide anything both useful and portable
1390 in this area anymore).
1391
Martin v. Löwis44f86962001-09-05 13:44:54 +00001392- Asynchronous timeout actions are available through the new class
1393 threading.Timer.
1394
Tim Peters78526162001-09-05 00:53:45 +00001395- math.log and math.log10 now return sensible results for even huge
1396 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1397
Tim Petersbdee63f2001-09-02 03:40:59 +00001398- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001399 currently held. See the docs for the imp module.
1400
Tim Petersbdee63f2001-09-02 03:40:59 +00001401- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001402 dumps containing ints written on platforms where Python ints are 8 bytes.
1403 When read on a box where Python ints are 4 bytes, such values are
1404 converted to Python longs.
1405
Tim Petersbdee63f2001-09-02 03:40:59 +00001406- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001407 code objects is no longer allowed. This plugs a security hole.
1408
Steve Purcell6091cd62001-09-06 16:05:17 +00001409- unittest.TestResult instances no longer store references to tracebacks
1410 generated by test failures. This prevents unexpected dangling references
1411 to objects that should be garbage collected between tests.
1412
Tim Petersedc99312001-08-22 21:36:50 +00001413Tools
1414
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001415- Tools/scripts/fixdiv.py has been added which can be used to fix
1416 division operators as per PEP 238.
1417
Tim Petersedc99312001-08-22 21:36:50 +00001418Build
1419
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001420- If you are an adventurous person using Mac OS X you may want to look at
1421 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1422 application, which can be used for experimenting with Carbon or Cocoa.
1423 Discussion of this on pythonmac-sig, please.
1424
Tim Peters7eea37e2001-09-04 22:08:56 +00001425C API
1426
1427- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001428
Tim Peters9fffa3e2001-09-04 05:14:19 +00001429- Note that PyLong_AsDouble can fail! This has always been true, but no
1430 callers checked for it. It's more likely to fail now, because overflow
1431 errors are properly detected now. The proper way to check:
1432
1433 double x = PyLong_AsDouble(some_long_object);
1434 if (x == -1.0 && PyErr_Occurred()) {
1435 /* The conversion failed. */
1436 }
1437
Tim Petersbdee63f2001-09-02 03:40:59 +00001438- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001439 compile but will not participate in GC. To upgrade an extension
1440 module:
1441
1442 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001443
Neil Schemenauer4042c692001-08-30 15:38:01 +00001444 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1445 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001446
Neil Schemenauer4042c692001-08-30 15:38:01 +00001447 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1448 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001449
Neil Schemenauer4042c692001-08-30 15:38:01 +00001450 - remove PyGC_HEAD_SIZE from object size calculations
1451
1452 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1453
Tim Petersbdee63f2001-09-02 03:40:59 +00001454- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001455 These can be used safely to construct string objects from a
1456 sprintf-style format string (similar to the format string supported
1457 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001458
Tim Petersedc99312001-08-22 21:36:50 +00001459New platforms
1460
Tim Petersb7da0902001-09-02 23:01:43 +00001461- Stephen Hansen contributed patches sufficient to get a clean compile
1462 under Borland C (Windows), but he reports problems running it and ran
1463 out of time to complete the port. Volunteers? Expect a MemoryError
1464 when importing the types module; this is probably shallow, and
1465 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001466
Tim Petersedc99312001-08-22 21:36:50 +00001467Tests
1468
1469Windows
1470
Tim Peters6e13a562001-09-06 00:32:15 +00001471- Large file support is now enabled on Win32 platforms as well as on
1472 Win64. This means that, for example, you can use f.tell() and f.seek()
1473 to manipulate files larger than 2 gigabytes (provided you have enough
1474 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001475 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1476 filesize limit, and large file support makes no difference there.
1477 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1478 NTFS has no practical limit on file size, and files of any size can be
1479 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001480
Tim Petersbdee63f2001-09-02 03:40:59 +00001481- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001482 points to command.com (patch from Brian Quinlan).
1483
Tim Petersedc99312001-08-22 21:36:50 +00001484
Tim Peters20f51a72001-07-21 02:31:40 +00001485What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001486Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001487===========================
1488
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001489Build
1490
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001491- Tim Peters developed a brand new Windows installer using Wise 8.1,
1492 generously donated to us by Wise Solutions.
1493
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001494- configure supports a new option --enable-unicode, with the values
1495 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1496 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001497
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001498- A new configure option --enable-framework builds a Mac OS X framework,
1499 which "make frameworkinstall" will install. This provides a starting
1500 point for more mac-like functionality, join pythonmac-sig@python.org
1501 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001502
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001503- The NeXT platform is no longer supported.
1504
1505- The `new' module is now statically linked.
1506
Tim Peters0afb6092001-08-15 06:06:44 +00001507Tools
1508
1509- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001510 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001511 the module docstring for details.
1512
Tim Peters20f51a72001-07-21 02:31:40 +00001513Tests
1514
Tim Peters5e824c32001-08-12 22:25:01 +00001515- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001516 platforms, allowing to give clearer test result output. regrtest
1517 also has optional --use/-u switch to run normally disabled tests
1518 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001519
Tim Peters20f51a72001-07-21 02:31:40 +00001520- Several new tests in the standard test suite, with special thanks to
1521 Nick Mathewson.
1522
1523Core
1524
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001525- The floor division operator // has been added as outlined in PEP
1526 238. The / operator still provides classic division (and will until
1527 Python 3.0) unless "from __future__ import division" is included, in
1528 which case the / operator will provide true division. The operator
1529 module provides truediv() and floordiv() functions. Augmented
1530 assignment variants are included, as are the equivalent overloadable
1531 methods and C API methods. See the PEP for a full discussion:
1532 <http://python.sf.net/peps/pep-0238.html>
1533
Tim Peters6cd6a822001-08-17 22:11:27 +00001534- Future statements are now effective in simulated interactive shells
1535 (like IDLE). This should "just work" by magic, but read Michael
1536 Hudson's "Future statements in simulated shells" PEP 264 for full
1537 details: <http://python.sf.net/peps/pep-0264.html>.
1538
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001539- The type/class unification (PEP 252-253) was integrated into the
1540 trunk and is not so tentative any more (the exact specification of
1541 some features is still tentative). A lot of work has done on fixing
1542 bugs and adding robustness and features (performance still has to
1543 come a long way).
1544
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001545- Warnings about a mismatch in the Python API during extension import
1546 now use the Python warning framework (which makes it possible to
1547 write filters for these warnings).
1548
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001549- A function's __dict__ (aka func_dict) will now always be a
1550 dictionary. It used to be possible to delete it or set it to None,
1551 but now both actions raise TypeErrors. It is still legal to set it
1552 to a dictionary object. Getting func.__dict__ before any attributes
1553 have been assigned now returns an empty dictionary instead of None.
1554
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001555- A new command line option, -E, was added which disables the use of
1556 all environment variables, or at least those that are specifically
1557 significant to Python. Usually those have a name starting with
1558 "PYTHON". This was used to fix a problem where the tests fail if
1559 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1560 older distribution.
1561
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001562Library
1563
Tim Peters5e824c32001-08-12 22:25:01 +00001564- New class Differ and new functions ndiff() and restore() in difflib.py.
1565 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001566 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001567
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001568- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1569 value using the minimal quoting required for the value; more
1570 reliable than using xml.sax.saxutils.escape() for attribute values.
1571
1572- Readline completion support for cmd.Cmd was added.
1573
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001574- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1575
1576- Added function threading.BoundedSemaphore()
1577
1578- Added Ka-Ping Yee's cgitb.py module.
1579
1580- The `new' module now exposes the CO_xxx flags.
1581
Martin v. Löwis560da622001-11-24 09:24:51 +00001582- The gc module offers the get_referents function.
1583
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001584New platforms
1585
1586C API
1587
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001588- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1589 which provide a cross-platform implementations for the
1590 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1591 the standard sprintf() and vsprintf() C lib APIs, these versions
1592 apply bounds checking on the used buffer which enhances protection
1593 against buffer overruns.
1594
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001595- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001596 and extensions using different Unicode widths is rendered next to
1597 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001598 will result in an ImportError. Unicode extensions writers must make
1599 sure to check the Unicode width compatibility in their extensions by
1600 using at least one of the mangled Unicode APIs in the extension.
1601
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001602- Two new flags METH_NOARGS and METH_O are available in method definition
1603 tables to simplify implementation of methods with no arguments and a
1604 single untyped argument. Calling such methods is more efficient than
1605 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1606 deprecated.
1607
Tim Petersc1731372001-08-04 08:12:36 +00001608Windows
1609
1610- "import module" now compiles module.pyw if it exists and nothing else
1611 relevant is found.
1612
Tim Peters20f51a72001-07-21 02:31:40 +00001613
Guido van Rossum55a78992001-07-17 17:22:32 +00001614What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001615Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001616===========================
1617
1618Core
Tim Petersa814db52001-05-14 07:05:58 +00001619
Tim Peters6d6c1a32001-08-02 04:15:00 +00001620- TENTATIVELY, a large amount of code implementing much of what's
1621 described in PEP 252 (Making Types Look More Like Classes) and PEP
1622 253 (Subtyping Built-in Types) was added. This will be released
1623 with Python 2.2a1. Documentation will be provided separately
1624 through http://www.python.org/2.2/. The purpose of releasing this
1625 with Python 2.2a1 is to test backwards compatibility. It is
1626 possible, though not likely, that a decision is made not to release
1627 this code as part of 2.2 final, if any serious backwards
1628 incompapatibilities are found during alpha testing that cannot be
1629 repaired.
1630
Guido van Rossum55a78992001-07-17 17:22:32 +00001631- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001632 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001633 more 'yield' statements. See PEP 255. Since this adds a new
1634 keyword to the language, this feature must be enabled by including a
1635 future statement: "from __future__ import generators" (see PEP 236).
1636 Generators will become a standard feature in a future release
1637 (probably 2.3). Without this future statement, 'yield' remains an
1638 ordinary identifier, but a warning is issued each time it is used.
1639 (These warnings currently don't conform to the warnings framework of
1640 PEP 230; we intend to fix this in 2.2a2.)
1641
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001642- The UTF-16 codec was modified to be more RFC compliant. It will now
1643 only remove BOM characters at the start of the string and then
1644 only if running in native mode (UTF-16-LE and -BE won't remove a
1645 leading BMO character).
1646
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001647- Strings now have a new method .decode() to complement the already
1648 existing .encode() method. These two methods provide direct access
1649 to the corresponding decoders and encoders of the registered codecs.
1650
1651 To enhance the usability of the .encode() method, the special
1652 casing of Unicode object return values was dropped (Unicode objects
1653 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001654
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001655 Both methods will now return whatever the codec in charge of the
1656 requested encoding returns as object, e.g. Unicode codecs will
1657 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1658 will return u"äöü"). This enables codec writer to create codecs
1659 for various simple to use conversions.
1660
1661 New codecs were added to demonstrate these new features (the .encode()
1662 and .decode() columns indicate the type of the returned objects):
1663
1664 Name | .encode() | .decode() | Description
1665 ----------------------------------------------------------------------
1666 uu | string | string | UU codec (e.g. for email)
1667 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001668 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001669 zlib | string | string | zlib compression
1670 hex | string | string | 2-byte hex codec
1671 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1672
Mark Hammond2a0af792001-05-14 03:09:36 +00001673- Some operating systems now support the concept of a default Unicode
1674 encoding for file system operations. Notably, Windows supports 'mbcs'
1675 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001676 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001677 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001678
1679 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001680 functions that return filenames (such as os.listdir()) to return Python
1681 string objects pre-encoded using the default file system encoding for
1682 the platform. As this encoding is likely to be different from Python's
1683 default encoding, converting this name to a Unicode object before passing
1684 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001685 would attempt to use its default encoding (generally ASCII) rather than
1686 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001687
Tim Petersa814db52001-05-14 07:05:58 +00001688 In general, this change simply removes surprises when working with
1689 Unicode and the file system, making these operations work as you expect,
1690 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001691 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001692
Tim Peters61dff2b2001-05-08 15:43:37 +00001693- Float (and complex) literals in source code were evaluated to full
1694 precision only when running from a .py file; the same code loaded from a
1695 .pyc (or .pyo) file could suffer numeric differences starting at about the
1696 12th significant decimal digit. For example, on a machine with IEEE-754
1697 floating arithmetic,
1698
1699 x = 9007199254740992.0
1700 print long(x)
1701
1702 printed 9007199254740992 if run directly from .py, but 9007199254740000
1703 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1704 str(float) instead of repr(float) when building code objects. marshal
1705 now uses repr(float) instead, which should reproduce floats to full
1706 machine precision (assuming the platform C float<->string I/O conversion
1707 functions are of good quality).
1708
1709 This may cause floating-point results to change in some cases, and
1710 usually for the better, but may also cause numerically unstable
1711 algorithms to break.
1712
Tim Peters2f228e72001-05-13 00:19:31 +00001713- The implementation of dicts suffers fewer collisions, which has speed
1714 benefits. However, the order in which dict entries appear in dict.keys(),
1715 dict.values() and dict.items() may differ from previous releases for a
1716 given dict. Nothing is defined about this order, so no program should
1717 rely on it. Nevertheless, it's easy to write test cases that rely on the
1718 order by accident, typically because of printing the str() or repr() of a
1719 dict to an "expected results" file. See Lib/test/test_support.py's new
1720 sortdict(dict) function for a simple way to display a dict in sorted
1721 order.
1722
Tim Peters7a3bfc32001-06-12 01:22:22 +00001723- Many other small changes to dicts were made, resulting in faster
1724 operation along the most common code paths.
1725
Guido van Rossum10315822001-05-01 20:54:30 +00001726- Dictionary objects now support the "in" operator: "x in dict" means
1727 the same as dict.has_key(x).
1728
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001729- The update() method of dictionaries now accepts generic mapping
1730 objects. Specifically the argument object must support the .keys()
1731 and __getitem__() methods. This allows you to say, for example,
1732 {}.update(UserDict())
1733
Guido van Rossum10315822001-05-01 20:54:30 +00001734- Iterators were added; this is a generalized way of providing values
1735 to a for loop. See PEP 234. There's a new built-in function iter()
1736 to return an iterator. There's a new protocol to get the next value
1737 from an iterator using the next() method (in Python) or the
1738 tp_iternext slot (in C). There's a new protocol to get iterators
1739 using the __iter__() method (in Python) or the tp_iter slot (in C).
1740 Iterating (i.e. a for loop) over a dictionary generates its keys.
1741 Iterating over a file generates its lines.
1742
Tim Petersf553f892001-05-01 20:45:31 +00001743- The following functions were generalized to work nicely with iterator
1744 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001745 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001746 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1747 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001748 join() method of strings
1749 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001750 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1751 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001752 right-hand side of assignment statements with multiple targets, such as
1753 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001754
Tim Petersd85e1022001-05-11 21:51:48 +00001755- Accessing module attributes is significantly faster (for example,
1756 random.random or os.path or yourPythonModule.yourAttribute).
1757
Tim Peterse63415e2001-05-08 04:38:29 +00001758- Comparing dictionary objects via == and != is faster, and now works even
1759 if the keys and values don't support comparisons other than ==.
1760
Tim Peters95bf9392001-05-10 08:32:44 +00001761- Comparing dictionaries in ways other than == and != is slower: there were
1762 insecurities in the dict comparison implementation that could cause Python
1763 to crash if the element comparison routines for the dict keys and/or
1764 values mutated the dicts. Making the code bulletproof slowed it down.
1765
Tim Peterseb28ef22001-06-02 05:27:19 +00001766- Collisions in dicts are resolved via a new approach, which can help
1767 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001768 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001769 faster now. Thanks to Christian Tismer for pointing out the cause and
1770 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001771
Tim Peters52e155e2001-06-16 05:42:57 +00001772- repr() is much faster for large containers (dict, list, tuple).
1773
1774
Tim Petersa814db52001-05-14 07:05:58 +00001775Library
1776
Fred Drake960fdf92001-07-20 18:38:26 +00001777- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1778 were added to the string module. These a locale-indenpendent
1779 constants, unlike letters, lowercase, and uppercase. These are now
1780 use in appropriate locations in the standard library.
1781
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001782- The flags used in dlopen calls can now be configured using
1783 sys.setdlopenflags and queried using sys.getdlopenflags.
1784
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001785- Fredrik Lundh's xmlrpclib is now a standard library module. This
1786 provides full client-side XML-RPC support. In addition,
1787 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1788 one asyncore-based). Thanks to Eric Raymond for the documentation.
1789
Guido van Rossum643d3912001-07-05 14:46:25 +00001790- The xrange() object is simplified: it no longer supports slicing,
1791 repetition, comparisons, efficient 'in' checking, the tolist()
1792 method, or the start, stop and step attributes. See PEP 260.
1793
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001794- A new function fnmatch.filter to filter lists of file names was added.
1795
Barry Warsawffd674d2001-05-22 16:00:10 +00001796- calendar.py uses month and day names based on the current locale.
1797
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001798- strop is now *really* obsolete (this was announced before with 1.6),
1799 and issues DeprecationWarning when used (except for the four items
1800 that are still imported into string.py).
1801
Tim Petersa814db52001-05-14 07:05:58 +00001802- Cookie.py now sorts key+value pairs by key in output strings.
1803
1804- pprint.isrecursive(object) didn't correctly identify recursive objects.
1805 Now it does.
1806
Tim Peters95b3f782001-05-14 18:39:41 +00001807- pprint functions now much faster for large containers (tuple, list, dict).
1808
Tim Peters7b9542a2001-06-10 23:40:19 +00001809- New 'q' and 'Q' format codes in the struct module, corresponding to C
1810 types "long long" and "unsigned long long" (on Windows, __int64). In
1811 native mode, these can be used only when the platform C compiler supports
1812 these types (when HAVE_LONG_LONG is #define'd by the Python config
1813 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001814 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1815 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001816
Guido van Rossum83213cc2001-06-12 16:48:52 +00001817- The site module installs a new built-in function 'help' that invokes
1818 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1819 it displays a message reminding the user to use 'help()' or
1820 'help(object)'.
1821
Tim Petersa814db52001-05-14 07:05:58 +00001822Tests
1823
1824- New test_mutants.py runs dict comparisons where the key and value
1825 comparison operators mutute the dicts randomly during comparison. This
1826 rapidly causes Python to crash under earlier releases (not for the faint
1827 of heart: it can also cause Win9x to freeze or reboot!).
1828
1829- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001830 pprint.isreadable() return sensible results. Also verifies that simple
1831 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001832
Tim Peters4324aa32001-05-28 22:30:08 +00001833C API
1834
1835- Removed the unused last_is_sticky argument from the internal
1836 _PyTuple_Resize(). If this affects you, you were cheating.
1837
1838
Guido van Rossum55a78992001-07-17 17:22:32 +00001839======================================================================
1840
1841
Guido van Rossumffe13be2001-04-16 18:46:45 +00001842What's New in Python 2.1 (final)?
1843=================================
1844
1845We only changed a few things since the last release candidate, all in
1846Python library code:
1847
1848- A bug in the locale module was fixed that affected locales which
1849 define no grouping for numeric formatting.
1850
1851- A few bugs in the weakref module's implementations of weak
1852 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1853 and the test suite was updated to check for these bugs.
1854
1855- An old bug in the os.path.walk() function (introduced in Python
1856 2.0!) was fixed: a non-existent file would cause an exception
1857 instead of being ignored.
1858
1859- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1860 PyChecker.
1861
1862
Guido van Rossum5b08f132001-04-16 02:05:23 +00001863What's New in Python 2.1c2?
1864===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001865
Guido van Rossum5b08f132001-04-16 02:05:23 +00001866A flurry of small changes, and one showstopper fixed in the nick of
1867time made it necessary to release another release candidate. The list
1868here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001869
Guido van Rossum5b08f132001-04-16 02:05:23 +00001870Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001871
Guido van Rossum5b08f132001-04-16 02:05:23 +00001872- Tim discovered a nasty bug in the dictionary code, caused by
1873 PyDict_Next() calling dict_resize(), and the GC code's use of
1874 PyDict_Next() violating an assumption in dict_items(). This was
1875 fixed with considerable amounts of band-aid, but the net effect is a
1876 saner and more robust implementation.
1877
1878- Made a bunch of symbols static that were accidentally global.
1879
1880Build and Ports
1881
1882- The setup.py script didn't check for a new enough version of zlib
1883 (1.1.3 is needed). Now it does.
1884
1885- Changed "make clean" target to also remove shared libraries.
1886
1887- Added a more general warning about the SGI Irix optimizer to README.
1888
1889Library
1890
1891- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1892 omitted the slash between host and file.html.
1893
1894- The mailbox module's _Mailbox class contained a completely broken
1895 and undocumented seek() method. Ripped it out.
1896
1897- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1898 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1899
1900- Fixed a few last-minute bugs in unittest.
1901
1902Extensions
1903
1904- Reverted the patch to the OpenSSL code in socketmodule.c to support
1905 RAND_status() and the EGD, and the subsequent patch that tried to
1906 fix it for pre-0.9.5 versions; the problem with the patch is that on
1907 some systems it issues a warning whenever socket is imported, and
1908 that's unacceptable.
1909
1910Tests
1911
1912- Fixed the pickle tests to work with "import test.test_pickle".
1913
1914- Tweaked test_locale.py to actually run the test Windows.
1915
1916- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1917 not "wb" (which is not a valid mode at all).
1918
1919- Fix pstats browser crashes. Import readline if it exists to make
1920 the user interface nicer.
1921
1922- Add "import thread" to the top of test modules that import the
1923 threading module (test_asynchat and test_threadedtempfile). This
1924 prevents test failures caused by a broken threading module resulting
1925 from a previously caught failed import.
1926
1927- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1928 needed on some platforms (e.g. Solaris 8) when the tests are run
1929 twice in succession.
1930
1931- Skip rather than fail test_sunaudiodev if no audio device is found.
1932
1933
1934What's New in Python 2.1c1?
1935===========================
1936
1937This list was significantly updated when 2.1c2 was released; the 2.1c1
1938release didn't mention most changes that were actually part of 2.1c1:
1939
1940Legal
1941
1942- Copyright was assigned to the Python Software Foundation (PSF) and a
1943 PSF license (very similar to the CNRI license) was added.
1944
1945- The CNRI copyright notice was updated to include 2001.
1946
1947Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001948
Guido van Rossumc9932722001-04-12 02:31:27 +00001949- After a public outcry, assignment to __debug__ is no longer illegal;
1950 instead, a warning is issued. It will become illegal in 2.2.
1951
Guido van Rossum5b08f132001-04-16 02:05:23 +00001952- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1953 "%#x" now always prepends "0x", even if the value is zero.
1954
1955- Fixed some nits in the bytecode compiler.
1956
1957- Fixed core dumps when calling certain kinds of non-functions.
1958
1959- Fixed various core dumps caused by reference count bugs.
1960
1961Build and Ports
1962
1963- Use INSTALL_SCRIPT to install script files.
1964
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001965- New port: SCO Unixware 7, by Billy G. Allie.
1966
Guido van Rossum5b08f132001-04-16 02:05:23 +00001967- Updated RISCOS port.
1968
1969- Updated BeOS port and notes.
1970
1971- Various other porting problems resolved.
1972
1973Library
1974
1975- The TERMIOS and SOCKET modules are now truly obsolete and
1976 unnecessary. Their symbols are incorporated in the termios and
1977 socket modules.
1978
1979- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1980 better tests for pickling.
1981
1982- threading: make Condition.wait() robust against KeyboardInterrupt.
1983
1984- zipfile: add support to zipfile to support opening an archive
1985 represented by an open file rather than a file name. Fix bug where
1986 the archive was not properly closed. Fixed a bug in this bugfix
1987 where flush() was called for a read-only file.
1988
1989- imputil: added an uninstall() method to the ImportManager.
1990
1991- Canvas: fixed bugs in lower() and tkraise() methods.
1992
1993- SocketServer: API change (added overridable close_request() method)
1994 so that the TCP server can explicitly close the request.
1995
1996- pstats: Eric Raymond added a simple interactive statistics browser,
1997 invoked when the module is run as a script.
1998
1999- locale: fixed a problem in format().
2000
2001- webbrowser: made it work when the BROWSER environment variable has a
2002 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
2003 KDE 2. Fixed some other nits.
2004
2005- unittest: changes to allow using a different exception than
2006 AssertionError, and added a few more function aliases. Some other
2007 small changes.
2008
2009- urllib, urllib2: fixed redirect problems and a coupleof other nits.
2010
2011- asynchat: fixed a critical bug in asynchat that slipped through the
2012 2.1b2 release. Fixed another rare bug.
2013
2014- Fix some unqualified except: clauses (always a bad code example).
2015
2016XML
2017
2018- pyexpat: new API get_version_string().
2019
2020- Fixed some minidom bugs.
2021
2022Extensions
2023
2024- Fixed a core dump in _weakref. Removed the weakref.mapping()
2025 function (it adds nothing to the API).
2026
2027- Rationalized the use of header files in the readline module, to make
2028 it compile (albeit with some warnings) with the very recent readline
2029 4.2, without breaking for earlier versions.
2030
2031- Hopefully fixed a buffering problem in linuxaudiodev.
2032
2033- Attempted a fix to make the OpenSSL support in the socket module
2034 work again with pre-0.9.5 versions of OpenSSL.
2035
2036Tests
2037
2038- Added a test case for asynchat and asyncore.
2039
2040- Removed coupling between tests where one test failing could break
2041 another.
2042
2043Tools
2044
2045- Ping added an interactive help browser to pydoc, fixed some nits
2046 in the rest of the pydoc code, and added some features to his
2047 inspect module.
2048
2049- An updated python-mode.el version 4.1 which integrates Ken
2050 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2051 much nicer in XEmacs and Emacs. When stepping through your program
2052 with pdb, in either the shell window or the *Python* window, the
2053 source file and line will be tracked by an arrow. Very cool!
2054
2055- IDLE: syntax warnings in interactive mode are changed into errors.
2056
2057- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002058 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002059
2060- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002061
Barry Warsaw11e89c72001-04-11 20:37:57 +00002062
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002063What's New in Python 2.1 beta 2?
2064================================
2065
Guido van Rossum053ae352001-03-22 14:17:21 +00002066(Unlisted are many fixed bugs, more documentation, etc.)
2067
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002068Core language, builtins, and interpreter
2069
Guido van Rossum053ae352001-03-22 14:17:21 +00002070- The nested scopes work (enabled by "from __future__ import
2071 nested_scopes") is completed; in particular, the future now extends
2072 into code executed through exec, eval() and execfile(), and into the
2073 interactive interpreter.
2074
2075- When calling a base class method (e.g. BaseClass.__init__(self)),
2076 this is now allowed even if self is not strictly spoken a class
2077 instance (e.g. when using metaclasses or the Don Beaudry hook).
2078
2079- Slice objects are now comparable but not hashable; this prevents
2080 dict[:] from being accepted but meaningless.
2081
2082- Complex division is now calculated using less braindead algorithms.
2083 This doesn't change semantics except it's more likely to give useful
2084 results in extreme cases. Complex repr() now uses full precision
2085 like float repr().
2086
2087- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2088
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002089- It is illegal to assign to the name __debug__, which is set when the
2090 interpreter starts. It is effectively a compile-time constant.
2091
2092- A warning will be issued if a global statement for a variable
2093 follows a use or assignment of that variable.
2094
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002095Standard library
2096
Guido van Rossum053ae352001-03-22 14:17:21 +00002097- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2098 inspired by JUnit), is now part of the standard library. You now
2099 have a choice of two testing frameworks: unittest requires you to
2100 write testcases as separate code, doctest gathers them from
2101 docstrings. Both approaches have their advantages and
2102 disadvantages.
2103
2104- A new module Tix was added, which wraps the Tix extension library
2105 for Tk. With that module, it is not necessary to statically link
2106 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2107 require" command. See Demo/tix/.
2108
2109- tzparse.py is now obsolete.
2110
2111- In gzip.py, the seek() and tell() methods are removed -- they were
2112 non-functional anyway, and it's better if callers can test for their
2113 existence with hasattr().
2114
2115Python/C API
2116
2117- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2118 that's already in the dictionary during a PyDict_Next() iteration.
2119 This used to fail occasionally when a dictionary resize operation
2120 could be triggered that would rehash all the keys. All other
2121 modifications to the dictionary are still off-limits during a
2122 PyDict_Next() iteration!
2123
2124- New extended APIs related to passing compiler variables around.
2125
2126- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2127 implement isinstance() and issubclass().
2128
2129- Py_BuildValue() now has a "D" conversion to create a Python complex
2130 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002131
Fred Drake4e262a92001-03-22 18:26:47 +00002132- Extensions types which support weak references must now set the
2133 field allocated for the weak reference machinery to NULL themselves;
2134 this is done to avoid the cost of checking each object for having a
2135 weakly referencable type in PyObject_INIT(), since most types are
2136 not weakly referencable.
2137
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002138- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2139 free variables and cell variables to and from the frame's f_locals.
2140
2141- Variants of several functions defined in pythonrun.h have been added
2142 to support the nested_scopes future statement. The variants all end
2143 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2144 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2145 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002146 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002147
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002148Distutils
2149
2150- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2151 into the release tree.
2152
Tim Peters0e57abf2001-05-02 07:39:38 +00002153- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002154 (an uninstaller, more customization of the installer's display)
2155
2156- from Jack Jansen: added Mac-specific code to generate a dialog for
2157 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002158 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002159 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002160
2161- added 'platforms' and 'keywords' to the set of metadata that can be
2162 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002163
2164- applied patches from Jason Tishler to make the compiler class work with
2165 Cygwin.
2166
2167
Tim Peters2fe289a2001-03-01 22:19:38 +00002168What's New in Python 2.1 beta 1?
2169================================
Tim Petersd66595f2001-02-04 03:09:53 +00002170
2171Core language, builtins, and interpreter
2172
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002173- Following an outcry from the community about the amount of code
2174 broken by the nested scopes feature introduced in 2.1a2, we decided
2175 to make this feature optional, and to wait until Python 2.2 (or at
2176 least 6 months) to make it standard. The option can be enabled on a
2177 per-module basis by adding "from __future__ import nested_scopes" at
2178 the beginning of a module (before any other statements, but after
2179 comments and an optional docstring). See PEP 236 (Back to the
2180 __future__) for a description of the __future__ statement. PEP 227
2181 (Statically Nested Scopes) has been updated to reflect this change,
2182 and to clarify the semantics in a number of endcases.
2183
2184- The nested scopes code, when enabled, has been hardened, and most
2185 bugs and memory leaks in it have been fixed.
2186
2187- Compile-time warnings are now generated for a number of conditions
2188 that will break or change in meaning when nested scopes are enabled:
2189
2190 - Using "from...import *" or "exec" without in-clause in a function
2191 scope that also defines a lambda or nested function with one or
2192 more free (non-local) variables. The presence of the import* or
2193 bare exec makes it impossible for the compiler to determine the
2194 exact set of local variables in the outer scope, which makes it
2195 impossible to determine the bindings for free variables in the
2196 inner scope. To avoid the warning about import *, change it into
2197 an import of explicitly name object, or move the import* statement
2198 to the global scope; to avoid the warning about bare exec, use
2199 exec...in... (a good idea anyway -- there's a possibility that
2200 bare exec will be deprecated in the future).
2201
2202 - Use of a global variable in a nested scope with the same name as a
2203 local variable in a surrounding scope. This will change in
2204 meaning with nested scopes: the name in the inner scope will
2205 reference the variable in the outer scope rather than the global
2206 of the same name. To avoid the warning, either rename the outer
2207 variable, or use a global statement in the inner function.
2208
Neil Schemenauera35c6882001-02-27 04:45:05 +00002209- An optional object allocator has been included. This allocator is
2210 optimized for Python objects and should be faster and use less memory
2211 than the standard system allocator. It is not enabled by default
2212 because of possible thread safety problems. The allocator is only
2213 protected by the Python interpreter lock and it is possible that some
2214 extension modules require a thread safe allocator. The object
2215 allocator can be enabled by providing the "--with-pymalloc" option to
2216 configure.
2217
Tim Petersd66595f2001-02-04 03:09:53 +00002218Standard library
2219
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002220- pyexpat now detects the expat version if expat.h defines it. A
2221 number of additional handlers are provided, which are only available
2222 since expat 1.95. In addition, the methods SetParamEntityParsing and
2223 GetInputContext of Parser objects are available with 1.95.x
2224 only. Parser objects now provide the ordered_attributes and
2225 specified_attributes attributes. A new module expat.model was added,
2226 which offers a number of additional constants if 1.95.x is used.
2227
2228- xml.dom offers the new functions registerDOMImplementation and
2229 getDOMImplementation.
2230
2231- xml.dom.minidom offers a toprettyxml method. A number of DOM
2232 conformance issues have been resolved. In particular, Element now
2233 has an hasAttributes method, and the handling of namespaces was
2234 improved.
2235
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002236- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2237 getting information about live Python code, and pydoc.py, a module
2238 for interactively converting docstrings to HTML or text.
2239 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002240 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002241 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2242 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002243
Tim Peters1eff7962001-03-01 02:31:33 +00002244- New library module difflib.py, primarily packaging the SequenceMatcher
2245 class at the heart of the popular ndiff.py file-comparison tool.
2246
2247- doctest.py (a framework for verifying Python code examples in docstrings)
2248 is now part of the std library.
2249
Tim Petersd66595f2001-02-04 03:09:53 +00002250Windows changes
2251
Guido van Rossume3955a82001-03-02 14:05:59 +00002252- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2253 small GUI that lets you browse the module docstrings using your
2254 default web browser.
2255
Tim Peters1eff7962001-03-01 02:31:33 +00002256- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2257 Platforms) is implemented. See
2258
2259 http://python.sourceforge.net/peps/pep-0235.html
2260
2261 for full details, especially the "Current Lower-Left Semantics" section.
2262 The new Windows import rules are simpler than before:
2263
2264 A. If the PYTHONCASEOK environment variable exists, same as
2265 before: silently accept the first case-insensitive match of any
2266 kind; raise ImportError if none found.
2267
2268 B. Else search sys.path for the first case-sensitive match; raise
2269 ImportError if none found.
2270
2271 The same rules have been implented on other platforms with case-
2272 insensitive but case-preserving filesystems too (including Cygwin, and
2273 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002274
Tim Peters25a9ce32001-02-19 07:06:36 +00002275- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2276 what it's supposed to do (and does do under NT and 2000) via direct
2277 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002278 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002279 all Win9x systems before.
2280
Tim Peters1eff7962001-03-01 02:31:33 +00002281- Build: Subproject _test (effectively) renamed to _testcapi.
2282
Tim Peters2fe289a2001-03-01 22:19:38 +00002283New platforms
2284
2285- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2286 Thanks to Steven Majewski!
2287
2288- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2289 Tishler!
2290
Guido van Rossum9089b272001-03-02 06:49:50 +00002291- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2292 Schwertberger! See RISCOS/README for more information -- it seems
2293 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002294 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002295
Tim Peters25a9ce32001-02-19 07:06:36 +00002296
Tim Petersd7b5e882001-01-25 03:36:26 +00002297What's New in Python 2.1 alpha 2?
2298=================================
Tim Peters40ead762001-01-27 05:35:26 +00002299
Tim Petersd7b5e882001-01-25 03:36:26 +00002300Core language, builtins, and interpreter
2301
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002302- Scopes nest. If a name is used in a function or class, but is not
2303 local, the definition in the nearest enclosing function scope will
2304 be used. One consequence of this change is that lambda statements
2305 could reference variables in the namespaces where the lambda is
2306 defined. In some unusual cases, this change will break code.
2307
2308 In all previous version of Python, names were resolved in exactly
2309 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002310 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002311 function A is defined within a function B, the names bound in B are
2312 not visible in A. The new rules make names bound in B visible in A,
2313 unless A contains a name binding that hides the binding in B.
2314
2315 Section 4.1 of the reference manual describes the new scoping rules
2316 in detail. The test script in Lib/test/test_scope.py demonstrates
2317 some of the effects of the change.
2318
2319 The new rules will cause existing code to break if it defines nested
2320 functions where an outer function has local variables with the same
2321 name as globals or builtins used by the inner function. Example:
2322
2323 def munge(str):
2324 def helper(x):
2325 return str(x)
2326 if type(str) != type(''):
2327 str = helper(str)
2328 return str.strip()
2329
2330 Under the old rules, the name str in helper() is bound to the
2331 builtin function str(). Under the new rules, it will be bound to
2332 the argument named str and an error will occur when helper() is
2333 called.
2334
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002335- The compiler will report a SyntaxError if "from ... import *" occurs
2336 in a function or class scope. The language reference has documented
2337 that this case is illegal, but the compiler never checked for it.
2338 The recent introduction of nested scope makes the meaning of this
2339 form of name binding ambiguous. In a future release, the compiler
2340 may allow this form when there is no possibility of ambiguity.
2341
Tim Peters40ead762001-01-27 05:35:26 +00002342- repr(string) is easier to read, now using hex escapes instead of octal,
2343 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2344
2345 >>> "\texample \r\n" + chr(0) + chr(255)
2346 '\texample \r\n\x00\xff' # in 2.1
2347 '\011example \015\012\000\377' # in 2.0
2348
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002349- Functions are now compared and hashed by identity, not by value, since
2350 the func_code attribute is writable.
2351
Fred Drakefb9d7122001-02-01 20:00:40 +00002352- Weak references (PEP 205) have been added. This involves a few
2353 changes in the core, an extension module (_weakref), and a Python
2354 module (weakref). The weakref module is the public interface. It
2355 includes support for "explicit" weak references, proxy objects, and
2356 mappings with weakly held values.
2357
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002358- A 'continue' statement can now appear in a try block within the body
2359 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002360 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002361
Tim Petersd7b5e882001-01-25 03:36:26 +00002362Standard library
2363
Barry Warsaw30dbd142001-01-31 22:14:01 +00002364- mailbox.py now has a new class, PortableUnixMailbox which is
2365 identical to UnixMailbox but uses a more portable scheme for
2366 determining From_ separators. Also, the constructors for all the
2367 classes in this module have a new optional `factory' argument, which
2368 is a callable used when new message classes must be instantiated by
2369 the next() method.
2370
Tim Petersd7b5e882001-01-25 03:36:26 +00002371- random.py is now self-contained, and offers all the functionality of
2372 the now-deprecated whrandom.py. See the docs for details. random.py
2373 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002374 and restoring the internal state of the generator; and jumpahead(n),
2375 for quickly forcing the internal state to be the same as if n calls to
2376 random() had been made. The latter is particularly useful for multi-
2377 threaded programs, creating one instance of the random.Random() class for
2378 each thread, then using .jumpahead() to force each instance to use a
2379 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002380
Tim Peters0de88fc2001-02-01 04:59:18 +00002381- random.py's seed() function is new. For bit-for-bit compatibility with
2382 prior releases, use the whseed function instead. The new seed function
2383 addresses two problems: (1) The old function couldn't produce more than
2384 about 2**24 distinct internal states; the new one about 2**45 (the best
2385 that can be done in the Wichmann-Hill generator). (2) The old function
2386 sometimes produced identical internal states when passed distinct
2387 integers, and there was no simple way to predict when that would happen;
2388 the new one guarantees to produce distinct internal states for all
2389 arguments in [0, 27814431486576L).
2390
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002391- The socket module now supports raw packets on Linux. The socket
2392 family is AF_PACKET.
2393
Tim Peters9ea17ac2001-02-02 05:57:15 +00002394- test_capi.py is a start at running tests of the Python C API. The tests
2395 are implemented by the new Modules/_testmodule.c.
2396
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002397- A new extension module, _symtable, provides provisional access to the
2398 internal symbol table used by the Python compiler. A higher-level
2399 interface will be added on top of _symtable in a future release.
2400
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002401- Removed the obsolete soundex module.
2402
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002403- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2404 the isSameNode method; NamedNodeMap the get method.
2405
2406- xml.sax.expatreader supports the lexical handler property; it
2407 generates comment, startCDATA, and endCDATA events.
2408
Tim Petersee826f82001-01-31 19:39:44 +00002409Windows changes
2410
2411- Build procedure: the zlib project is built in a different way that
2412 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002413 the zlib binary used. See PCbuild\readme.txt for details. Your old
2414 zlib-related directories can be deleted; you'll need to download fresh
2415 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002416
Tim Peters9ea17ac2001-02-02 05:57:15 +00002417- Build: New subproject _test for the benefit of test_capi.py (see above).
2418
Tim Petersb16c56f2001-02-02 21:24:51 +00002419- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2420 interface to some Python compiler internals).
2421
2422- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002423 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002424
Tim Petersa3a3a032000-11-30 05:22:44 +00002425What's New in Python 2.1 alpha 1?
2426=================================
2427
2428Core language, builtins, and interpreter
2429
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002430- There is a new Unicode companion to the PyObject_Str() API
2431 called PyObject_Unicode(). It behaves in the same way as the
2432 former, but assures that the returned value is an Unicode object
2433 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002434
Guido van Rossumf98eda02001-01-17 15:54:45 +00002435- The comparison operators support "rich comparison overloading" (PEP
2436 207). C extension types can provide a rich comparison function in
2437 the new tp_richcompare slot in the type object. The cmp() function
2438 and the C function PyObject_Compare() first try the new rich
2439 comparison operators before trying the old 3-way comparison. There
2440 is also a new C API PyObject_RichCompare() (which also falls back on
2441 the old 3-way comparison, but does not constrain the outcome of the
2442 rich comparison to a Boolean result).
2443
2444 The rich comparison function takes two objects (at least one of
2445 which is guaranteed to have the type that provided the function) and
2446 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2447 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2448 object, which may be NotImplemented (in which case the tp_compare
2449 slot function is used as a fallback, if defined).
2450
2451 Classes can overload individual comparison operators by defining one
2452 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002453 __ge__. There are no explicit "reflected argument" versions of
2454 these; instead, __lt__ and __gt__ are each other's reflection,
2455 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2456 reflection (similar at the C level). No other implications are
2457 made; in particular, Python does not assume that == is the Boolean
2458 inverse of !=, or that < is the Boolean inverse of >=. This makes
2459 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002460
2461 Classes or types that want to implement (in)equality tests but not
2462 the ordering operators (i.e. unordered types) should implement ==
2463 and !=, and raise an error for the ordering operators.
2464
Guido van Rossuma88479f2001-01-18 14:28:08 +00002465 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002466 Boolean; e.g. a matrix type might want to return a matrix of bits
2467 for A < B, giving elementwise comparisons. Such types should ensure
2468 that any interpretation of their value in a Boolean context raises
2469 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2470 at the C level) to always raise an exception.
2471
Guido van Rossuma88479f2001-01-18 14:28:08 +00002472- Complex numbers use rich comparisons to define == and != but raise
2473 an exception for <, <=, > and >=. Unfortunately, this also means
2474 that cmp() of two complex numbers raises an exception when the two
2475 numbers differ. Since it is not mathematically meaningful to compare
2476 complex numbers except for equality, I hope that this doesn't break
2477 too much code.
2478
Tim Peters3389f192001-02-18 08:48:49 +00002479- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002480 not defined by the language, other than that it's arbitrary but
2481 consistent (see the Reference Manual). An implementation detail changed
2482 in 2.1a1 such that None now compares less than any other object. Code
2483 relying on this new behavior (like code that relied on the previous
2484 behavior) does so at its own risk.
2485
Barry Warsaw573b5412001-01-15 20:43:18 +00002486- Functions and methods now support getting and setting arbitrarily
2487 named attributes (PEP 232). Functions have a new __dict__
2488 (a.k.a. func_dict) which hold the function attributes. Methods get
2489 and set attributes on their underlying im_func. It is a TypeError
2490 to set an attribute on a bound method.
2491
Guido van Rossum051e3352001-01-15 19:11:10 +00002492- The xrange() object implementation has been improved so that
2493 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2494 limitation that in this case len(xrange(sys.maxint)) can't be
2495 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2496 work fine as long as the index i doesn't actually reach 2**31.
2497 (Python uses regular ints for sequence and string indices; fixing
2498 that is much more work.)
2499
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002500- Two changes to from...import:
2501
Guido van Rossumba381232001-02-03 15:06:40 +00002502 1) "from M import X" now works even if (after loading module M)
2503 sys.modules['M'] is not a real module; it's basically a getattr()
2504 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002505
2506 2) "from M import *" now looks for M.__all__ to decide which names to
2507 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2508 filters out names starting with '_' as before. Whether or not
2509 __all__ exists, there's no restriction on the type of M.
2510
Guido van Rossumf61f1662001-01-10 20:13:55 +00002511- File objects have a new method, xreadlines(). This is the fastest
2512 way to iterate over all lines in a file:
2513
2514 for line in file.xreadlines():
2515 ...do something to line...
2516
2517 See the xreadlines module (mentioned below) for how to do this for
2518 other file-like objects.
2519
2520- Even if you don't use file.xreadlines(), you may expect a speedup on
2521 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002522 quite a bit in platform-specific ways: on systems (like Linux) that
2523 support flockfile(), getc_unlocked(), and funlockfile(), those are
2524 used by default. On systems (like Windows) without getc_unlocked(),
2525 a complicated (but still thread-safe) method using fgets() is used by
2526 default.
2527
Tim Petersd52269b2001-01-25 06:23:18 +00002528 You can force use of the fgets() method by #define'ing
2529 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002530 getc_unlocked()).
2531
Tim Petersd52269b2001-01-25 06:23:18 +00002532 You can force fgets() not to be used by #define'ing
2533 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002534 test_bufio.py fails -- and let us know if it does!).
2535
2536- In addition, the fileinput module, while still slower than the other
2537 methods on most platforms, has been sped up too, by using
2538 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002539
2540- Support for run-time warnings has been added, including a new
2541 command line option (-W) to specify the disposition of warnings.
2542 See the description of the warnings module below.
2543
2544- Extensive changes have been made to the coercion code. This mostly
2545 affects extension modules (which can now implement mixed-type
2546 numerical operators without having to use coercion), but
2547 occasionally, in boundary cases the coercion semantics have changed
2548 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002549 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002550 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002551 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002552
Guido van Rossumf98eda02001-01-17 15:54:45 +00002553- In connection with the coercion changes, a new built-in singleton
2554 object, NotImplemented is defined. This can be returned for
2555 operations that wish to indicate they are not implemented for a
2556 particular combination of arguments. From C, this is
2557 Py_NotImplemented.
2558
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002559- The interpreter accepts now bytecode files on the command line even
2560 if they do not have a .pyc or .pyo extension. On Linux, after executing
2561
Martin v. Löwise214baa2001-02-04 22:37:56 +00002562import imp,sys,string
2563magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2564reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2565open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002566
2567 any byte code file can be used as an executable (i.e. as an argument
2568 to execve(2)).
2569
Tim Peters9940b802000-12-01 07:59:35 +00002570- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002571 character. In 1.6 and earlier, they never produced a sign,
2572 and raised an error if the value of the long was too large
2573 to fit in a Python int. In 2.0, they produced a sign if and
2574 only if too large to fit in an int. This was inconsistent
2575 across platforms (because the size of an int varies across
2576 platforms), and inconsistent with hex() and oct(). Example:
2577
2578 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002579 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002580 'ffffffbe' # in 2.0 and before, on 32-bit machines
2581 >>> hex(-0x42L)
2582 '-0x42L' # in all versions of Python
2583
Tim Peters9940b802000-12-01 07:59:35 +00002584 The behavior of %d formats for negative Python longs remains
2585 the same as in 2.0 (although in 1.6 and before, they raised
2586 an error if the long didn't fit in a Python int).
2587
2588 %u formats don't make sense for Python longs, but are allowed
2589 and treated the same as %d in 2.1. In 2.0, a negative long
2590 formatted via %u produced a sign if and only if too large to
2591 fit in an int. In 1.6 and earlier, a negative long formatted
2592 via %u raised an error if it was too big to fit in an int.
2593
Guido van Rossum3661d392000-12-12 22:10:31 +00002594- Dictionary objects have an odd new method, popitem(). This removes
2595 an arbitrary item from the dictionary and returns it (in the form of
2596 a (key, value) pair). This can be useful for algorithms that use a
2597 dictionary as a bag of "to do" items and repeatedly need to pick one
2598 item. Such algorithms normally end up running in quadratic time;
2599 using popitem() they can usually be made to run in linear time.
2600
Tim Peters36cdad12000-12-29 02:06:45 +00002601Standard library
2602
Thomas Woutersfe385252001-01-19 23:16:56 +00002603- In the time module, the time argument to the functions strftime,
2604 localtime, gmtime, asctime and ctime is now optional, defaulting to
2605 the current time (in the local timezone).
2606
Guido van Rossumda91f222001-01-15 16:36:08 +00002607- The ftplib module now defaults to passive mode, which is deemed a
2608 more useful default given that clients are often inside firewalls
2609 these days. Note that this could break if ftplib is used to connect
2610 to a *server* that is inside a firewall, from outside; this is
2611 expected to be a very rare situation. To fix that, you can call
2612 ftp.set_pasv(0).
2613
Martin v. Löwis10a27872001-01-13 09:54:41 +00002614- The module site now treats .pth files not only for path configuration,
2615 but also supports extensions to the initialization code: Lines starting
2616 with import are executed.
2617
Guido van Rossumf61f1662001-01-10 20:13:55 +00002618- There's a new module, warnings, which implements a mechanism for
2619 issuing and filtering warnings. There are some new built-in
2620 exceptions that serve as warning categories, and a new command line
2621 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2622 turns warnings into errors). warnings.warn(message[, category])
2623 issues a warning message; this can also be called from C as
2624 PyErr_Warn(category, message).
2625
2626- A new module xreadlines was added. This exports a single factory
2627 function, xreadlines(). The intention is that this code is the
2628 absolutely fastest way to iterate over all lines in an open
2629 file(-like) object:
2630
2631 import xreadlines
2632 for line in xreadlines.xreadlines(file):
2633 ...do something to line...
2634
2635 This is equivalent to the previous the speed record holder using
2636 file.readlines(sizehint). Note that if file is a real file object
2637 (as opposed to a file-like object), this is equivalent:
2638
2639 for line in file.xreadlines():
2640 ...do something to line...
2641
Tim Peters36cdad12000-12-29 02:06:45 +00002642- The bisect module has new functions bisect_left, insort_left,
2643 bisect_right and insort_right. The old names bisect and insort
2644 are now aliases for bisect_right and insort_right. XXX_right
2645 and XXX_left methods differ in what happens when the new element
2646 compares equal to one or more elements already in the list: the
2647 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002648 right. Code that doesn't care where equal elements end up should
2649 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002650
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002651- The new curses.panel module wraps the panel library that forms part
2652 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2653
Guido van Rossumf61f1662001-01-10 20:13:55 +00002654- The SocketServer module now sets the allow_reuse_address flag by
2655 default in the TCPServer class.
2656
2657- A new function, sys._getframe(), returns the stack frame pointer of
2658 the caller. This is intended only as a building block for
2659 higher-level mechanisms such as string interpolation.
2660
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002661- The pyexpat module supports a number of new handlers, which are
2662 available only in expat 1.2. If invocation of a callback fails, it
2663 will report an additional frame in the traceback. Parser objects
2664 participate now in garbage collection. If expat reports an unknown
2665 encoding, pyexpat will try to use a Python codec; that works only
2666 for single-byte charsets. The parser type objects is exposed as
2667 XMLParserObject.
2668
2669- xml.dom now offers standard definitions for symbolic node type and
2670 exception code constants, and a hierarchy of DOM exceptions. minidom
2671 was adjusted to use them.
2672
2673- The conformance of xml.dom.minidom to the DOM specification was
2674 improved. It detects a number of additional error cases; the
2675 previous/next relationship works even when the tree is modified;
2676 Node supports the normalize() method; NamedNodeMap, DocumentType and
2677 DOMImplementation classes were added; Element supports the
2678 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2679 method.
2680
Guido van Rossumf61f1662001-01-10 20:13:55 +00002681Build issues
2682
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002683- For Unix (and Unix-compatible) builds, configuration and building of
2684 extension modules is now greatly automated. Rather than having to
2685 edit the Modules/Setup file to indicate which modules should be
2686 built and where their include files and libraries are, a
2687 distutils-based setup.py script now takes care of building most
2688 extension modules. All extension modules built this way are built
2689 as shared libraries. Only a few modules that must be linked
2690 statically are still listed in the Setup file; you won't need to
2691 edit their configuration.
2692
2693- Python should now build out of the box on Cygwin. If it doesn't,
2694 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002695
2696- Python now always uses its own (renamed) implementation of getopt()
2697 -- there's too much variation among C library getopt()
2698 implementations.
2699
2700- C++ compilers are better supported; the CXX macro is always set to a
2701 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002702
Tim Petersd92dfe02000-12-12 01:18:41 +00002703Windows changes
2704
2705- select module: By default under Windows, a select() call
2706 can specify no more than 64 sockets. Python now boosts
2707 this Microsoft default to 512. If you need even more than
2708 that, see the MS docs (you'll need to #define FD_SETSIZE
2709 and recompile Python from source).
2710
Guido van Rossumf61f1662001-01-10 20:13:55 +00002711- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2712 subdirectory is no more!
2713
Tim Petersa3a3a032000-11-30 05:22:44 +00002714
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002715What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002716=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002717
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002718Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002719changes are in the file HISTORY. If you are making the jump directly
2720from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2721HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002722
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002723Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2724the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2725http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002726
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002727--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002728
2729======================================================================
2730
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002731What's new in 2.0 (since release candidate 1)?
2732==============================================
2733
2734Standard library
2735
2736- The copy_reg module was modified to clarify its intended use: to
2737 register pickle support for extension types, not for classes.
2738 pickle() will raise a TypeError if it is passed a class.
2739
2740- Fixed a bug in gettext's "normalize and expand" code that prevented
2741 it from finding an existing .mo file.
2742
2743- Restored support for HTTP/0.9 servers in httplib.
2744
Tim Peters989b7b92000-10-16 20:24:53 +00002745- The math module was changed to stop raising OverflowError in case of
2746 underflow, and return 0 instead in underflow cases. Whether Python
2747 used to raise OverflowError in case of underflow was platform-
2748 dependent (it did when the platform math library set errno to ERANGE
2749 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002750
2751- Fixed a bug in StringIO that occurred when the file position was not
2752 at the end of the file and write() was called with enough data to
2753 extend past the end of the file.
2754
2755- Fixed a bug that caused Tkinter error messages to get lost on
2756 Windows. The bug was fixed by replacing direct use of
2757 interp->result with Tcl_GetStringResult(interp).
2758
2759- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2760 redirect response.
2761
2762- Several changes were made to distutils: Some debugging code was
2763 removed from util. Fixed the installer used when an external zip
2764 program (like WinZip) is not found; the source code for this
2765 installer is in Misc/distutils. check_lib() was modified to behave
2766 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2767 test for whether installed modules are on sys.path was changed to
2768 use both normcase() and normpath().
2769
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002770- Several minor bugs were fixed in the xml package (the minidom,
2771 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002772
2773- The regression test driver (regrtest.py) behavior when invoked with
2774 -l changed: It now reports a count of objects that are recognized as
2775 garbage but not freed by the garbage collector.
2776
Tim Peters989b7b92000-10-16 20:24:53 +00002777- The regression test for the math module was changed to test
2778 exceptional behavior when the test is run in verbose mode. Python
2779 cannot yet guarantee consistent exception behavior across platforms,
2780 so the exception part of test_math is run only in verbose mode, and
2781 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002782
2783Internals
2784
2785- PyOS_CheckStack() has been disabled on Win64, where it caused
2786 test_sre to fail.
2787
2788Build issues
2789
2790- Changed compiler flags, so that gcc is always invoked with -Wall and
2791 -Wstrict-prototypes. Users compiling Python with GCC should see
2792 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002793 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002794 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002795
Tim Petersa3a3a032000-11-30 05:22:44 +00002796- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002797
2798Tools and other miscellany
2799
2800- The compiler in Tools/compiler was updated to support the new
2801 language features introduced in 2.0: extended print statement, list
2802 comprehensions, and augmented assignments. The new compiler should
2803 also be backwards compatible with Python 1.5.2; the compiler will
2804 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002805 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002806
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002807What's new in 2.0 release candidate 1 (since beta 2)?
2808=====================================================
2809
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002810What is release candidate 1?
2811
2812We believe that release candidate 1 will fix all known bugs that we
2813intend to fix for the 2.0 final release. This release should be a bit
2814more stable than the previous betas. We would like to see even more
2815widespread testing before the final release, so we are producing this
2816release candidate. The final release will be exactly the same unless
2817any show-stopping (or brown bag) bugs are found by testers of the
2818release candidate.
2819
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002820All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002821to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002822
2823Core language, builtins, and interpreter
2824
2825- A bug that caused crashes when __coerce__ was used with augmented
2826 assignment, e.g. +=, was fixed.
2827
2828- Raise ZeroDivisionError when raising zero to a negative number,
2829 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2830 power operator and the result of math.pow(0.0, -2.0) will vary by
2831 platform. On Linux, it raises a ValueError.
2832
2833- A bug in Unicode string interpolation was fixed that occasionally
2834 caused errors with formats including "%%". For example, the
2835 following expression "%% %s" % u"abc" no longer raises a TypeError.
2836
2837- Compilation of deeply nested expressions raises MemoryError instead
2838 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2839
2840- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2841 rendering them useless. They are now written in binary mode again.
2842
2843Standard library
2844
2845- Keyword arguments are now accepted for most pattern and match object
2846 methods in SRE, the standard regular expression engine.
2847
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002848- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002849 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002850
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002851- Several bugs in the Unicode handling and error handling in _tkinter
2852 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002853
2854- Fix memory management errors in Merge() and Tkapp_Call() routines.
2855
2856- Several changes were made to cStringIO to make it compatible with
2857 the file-like object interface and with StringIO. If operations are
2858 performed on a closed object, an exception is raised. The truncate
2859 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002860 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002861
2862- There were many changes made to the linuxaudiodev module and its
2863 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002864 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002865
2866 Note that this module is named poorly, because it should work
2867 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002868 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002869
2870 The module now raises exceptions when errors occur instead of
2871 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2872 audio) and defines a getptr() method that calls the
2873 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2874
2875- The library_version attribute, introduced in an earlier beta, was
2876 removed because it can not be supported with early versions of the C
2877 readline library, which provides no way to determine the version at
2878 compile-time.
2879
2880- The binascii module is now enabled on Win64.
2881
Tim Peters46446d62000-10-09 21:19:31 +00002882- tokenize.py no longer suffers "recursion depth" errors when parsing
2883 programs with very long string literals.
2884
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002885Internals
2886
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002887- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002888 which is called when the interpreter starts up to determine where
2889 the standard library is installed. These vulnerabilities affect all
2890 previous versions of Python and can be exploited by setting very
2891 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2892 setuid Python script, although use of the wrapper in
2893 Misc/setuid-prog.c will eliminate the vulnerability.
2894
2895- Fixed garbage collection bugs in instance creation that were
2896 triggered when errors occurred during initialization. The solution,
2897 applied in cPickle and in PyInstance_New(), is to call
2898 PyObject_GC_Init() after the initialization of the object's
2899 container attributes is complete.
2900
2901- pyexpat adds definitions of PyModule_AddStringConstant and
2902 PyModule_AddObject if the Python version is less than 2.0, which
2903 provides compatibility with PyXML on Python 1.5.2.
2904
2905- If the platform has a bogus definition for LONG_BIT (the number of
2906 bits in a long), an error will be reported at compile time.
2907
2908- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2909 collection crashes and possibly other, unreported crashes.
2910
2911- Fixed a memory leak in _PyUnicode_Fini().
2912
2913Build issues
2914
2915- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002916 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002917 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002918
2919- The mmap.PAGESIZE constant is now initialized using sysconf when
2920 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2921
2922- The md5 file should now compile on all platforms.
2923
2924- The select module now compiles on platforms that do not define
2925 POLLRDNORM and related constants.
2926
2927- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002928 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002929
Jeremy Hylton10921202000-10-09 18:34:12 +00002930- BeOS: A number of changes were made to the build and installation
2931 process. ar-fake now operates on a directory of object files.
2932 dl_export.h is gone, and its macros now appear on the mwcc command
2933 line during build on PPC BeOS.
2934
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002935- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002936 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002937
2938- Cygwin: Support for shared libraries, Tkinter, and sockets.
2939
2940- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2941
2942Tools and other miscellany
2943
2944- Removed debugging prints from main used with freeze.
2945
Tim Peters46446d62000-10-09 21:19:31 +00002946- IDLE auto-indent no longer crashes when it encounters Unicode
2947 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002948
2949What's new in 2.0 beta 2 (since beta 1)?
2950========================================
2951
2952Core language, builtins, and interpreter
2953
Tim Peters482c0212000-09-26 06:33:09 +00002954- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002955 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002956
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002957- Add -h and -V command line options to print the usage message and
2958 Python version number and exit immediately.
2959
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002960- eval() and exec accept Unicode objects as code parameters.
2961
2962- getattr() and setattr() now also accept Unicode objects for the
2963 attribute name, which are converted to strings using the default
2964 encoding before lookup.
2965
2966- Multiplication on string and Unicode now does proper bounds
2967 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2968 string is too long."
2969
2970- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002971 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002972
Jeremy Hylton1b618592000-09-26 05:32:36 +00002973
2974Standard library and extensions
2975
Guido van Rossum5b08f132001-04-16 02:05:23 +00002976- socket module: the OpenSSL code now adds support for RAND_status()
2977 and EGD (Entropy Gathering Device).
2978
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002979- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002980 argument checking; it still takes no arguments.
2981
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002982- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002983
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002984- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002985
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002986- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002987
2988- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002989 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002990
2991- copy: Copy Unicode objects atomically.
2992
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002993- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002994
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002995- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002996
Fred Drake67233bc2000-09-26 16:40:27 +00002997- dbm: Add get() and setdefault() methods to dbm object. Add constant
2998 `library' to module that names the library used. Added doc strings
2999 and method names to error messages. Uses configure to determine
3000 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
3001 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003002
3003- distutils: Update to version 0.9.3.
3004
3005- dl: Add several dl.RTLD_ constants.
3006
3007- fpectl: Now supported on FreeBSD.
3008
3009- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
3010 found by the collector will be saved in gc.garbage. This is useful
3011 for debugging a program that creates reference cycles.
3012
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003013- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003014 of HTTP class. Do not close socket on zero-length response. Do not
3015 crash when server sends invalid content-length header.
3016
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003017- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003018
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003019- marshal: When reading a short, sign-extend on platforms where shorts
3020 are bigger than 16 bits. When reading a long, repair the unportable
3021 sign extension that was being done for 64-bit machines. (It assumed
3022 that signed right shift sign-extends.)
3023
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003024- operator: Add contains(), invert(), __invert__() as aliases for
3025 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003026
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003027- os: Add support for popen2() and popen3() on all platforms where
3028 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003029
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003030- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003031 clicking on a file in Explorer (or passing the file name to the
3032 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003033
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003034- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003035 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003036
3037- pickle: Now raises ValueError when an invalid pickle that contains
3038 a non-string repr where a string repr was expected. This behavior
3039 matches cPickle.
3040
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003041- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003042
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003043- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003044
3045- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003046 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003047 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003048
3049- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003050 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003051
3052- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003053 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003054 few cycles during startup since the first call to
3055 setdefaultencoding() will initialize the codec registry and the
3056 encodings package.
3057
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003058- socket: Support for size hint in readlines() method of object returned
3059 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003060
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003061- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003062 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003063 is followed by whitespace.
3064
Tim Petersa3a3a032000-11-30 05:22:44 +00003065- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003066
3067- struct: Check ranges for bytes and shorts.
3068
3069- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003070 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003071
3072- Tkinter: Image objects are now guaranteed to have unique ids. Set
3073 event.delta to zero if Tk version doesn't support mousewheel.
3074 Removed some debugging prints.
3075
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003076- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003077
Fred Drake67233bc2000-09-26 16:40:27 +00003078- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003079 which works around a bug in Norton AntiVirus 2000 that leads directly
3080 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003081
3082- xml: New version detection code allows PyXML to override standard
3083 XML package if PyXML version is greater than 0.6.1.
3084
Fred Drake64bb3802000-09-26 16:21:35 +00003085- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3086 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3087 tree only for nodes which are sufficiently interesting to a specific
3088 application. Does not provide the HTML-specific extensions. Still
3089 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003090
Fred Drake64bb3802000-09-26 16:21:35 +00003091- xml.sax: SAX 2 support for Python, including all the handler
3092 interfaces needed to process XML 1.0 compliant XML. Some
3093 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003094
Fred Drake64bb3802000-09-26 16:21:35 +00003095- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3096 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003097
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003098
Jeremy Hylton1b618592000-09-26 05:32:36 +00003099C API
3100
3101- Add three new convenience functions for module initialization --
3102 PyModule_AddObject(), PyModule_AddIntConstant(), and
3103 PyModule_AddStringConstant().
3104
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003105- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003106 removed and add #error to Python.h if NULL isn't defined after
3107 #include of stdio.h.
3108
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003109- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003110 backwards compatibility (at the source level) with old extensions.
3111
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003112- A wrapper API was added for signal() and sigaction(). Instead of
3113 either function, always use PyOS_getsig() to get a signal handler
3114 and PyOS_setsig() to set one. A new convenience typedef
3115 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003116
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003117- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003118 internal data buffer and size of a string object -- or the default
3119 encoded version of a Unicode object.
3120
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003121- PyString_Size() and PyString_AsString() accept Unicode objects.
3122
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003123- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003124 exists). INT_MAX and LONG_MAX will always be defined, even if
3125 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003126
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003127- PyFloat_FromString takes a second argument, pend, that was
3128 effectively useless. It is now officially useless but preserved for
3129 backwards compatibility. If the pend argument is not NULL, *pend is
3130 set to NULL.
3131
3132- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3133 for the attribute name. See note on getattr() above.
3134
3135- A few bug fixes to argument processing for Unicode.
3136 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3137 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3138 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003139 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003140
3141- Py_BuildValue accepts B format (for bgen-generated code).
3142
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003143
Jeremy Hylton1b618592000-09-26 05:32:36 +00003144Internals
3145
3146- On Unix, fix code for finding Python installation directory so that
3147 it works when argv[0] is a relative path.
3148
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003149- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003150 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003151 rather than by generating a copy of the object.
3152
Tim Peters482c0212000-09-26 06:33:09 +00003153- Several of the internal Unicode tables are much smaller now, and
3154 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003155
Jeremy Hylton97693b02000-09-26 17:42:51 +00003156- In the garbage collector: Fixed bug in collection of tuples. Fixed
3157 bug that caused some instances to be removed from the container set
3158 while they were still live. Fixed parsing in gc.set_debug() for
3159 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003160
3161- Fixed refcount problem in instance deallocation that only occurred
3162 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3163
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003164- On Windows, getpythonregpath is now protected against null data in
3165 registry key.
3166
3167- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003168 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003169
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003170
Jeremy Hylton1b618592000-09-26 05:32:36 +00003171Build and platform-specific issues
3172
3173- Better support of GNU Pth via --with-pth configure option.
3174
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003175- Python/C API now properly exposed to dynamically-loaded extension
3176 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003177
3178- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3179 Don't define MS_SYNC to be zero when it is undefined. Added missing
3180 prototypes in posixmodule.c.
3181
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003182- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003183 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003184
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003185- Fix largefile support on older NetBSD systems and OpenBSD by adding
3186 define for TELL64.
3187
3188
3189Tools and other miscellany
3190
3191- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3192
3193- freeze: The modulefinder now works with 2.0 opcodes.
3194
Tim Petersa3a3a032000-11-30 05:22:44 +00003195- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003196 Move hackery of sys.argv until after the Tk instance has been
3197 created, which allows the application-specific Tkinter
3198 initialization to be executed if present; also pass an explicit
3199 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003200
Jeremy Hylton1b618592000-09-26 05:32:36 +00003201
3202What's new in 2.0 beta 1?
3203=========================
3204
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003205Source Incompatibilities
3206------------------------
3207
3208None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3209such as single-argument append(), connect() and bind(), and changes to
3210str(long) and repr(float).
3211
3212
3213Binary Incompatibilities
3214------------------------
3215
3216- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3217with Python 2.0; these extensions will have to be rebuilt for Python
32182.0.
3219
3220- On Windows, attempting to import a third party extension built for
3221Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3222can do about this. Check your PYTHONPATH environment variable!
3223
3224- Python bytecode files (*.pyc and *.pyo) are not compatible between
3225releases.
3226
3227
3228Overview of Changes Since 1.6
3229-----------------------------
3230
3231There are many new modules (including brand new XML support through
3232the xml package, and i18n support through the gettext module); a list
3233of all new modules is included below. Lots of bugs have been fixed.
3234
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003235The process for making major new changes to the language has changed
3236since Python 1.6. Enhancements must now be documented by a Python
3237Enhancement Proposal (PEP) before they can be accepted.
3238
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003239There are several important syntax enhancements, described in more
3240detail below:
3241
3242 - Augmented assignment, e.g. x += 1
3243
3244 - List comprehensions, e.g. [x**2 for x in range(10)]
3245
3246 - Extended import statement, e.g. import Module as Name
3247
3248 - Extended print statement, e.g. print >> file, "Hello"
3249
3250Other important changes:
3251
3252 - Optional collection of cyclical garbage
3253
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003254Python Enhancement Proposal (PEP)
3255---------------------------------
3256
3257PEP stands for Python Enhancement Proposal. A PEP is a design
3258document providing information to the Python community, or describing
3259a new feature for Python. The PEP should provide a concise technical
3260specification of the feature and a rationale for the feature.
3261
3262We intend PEPs to be the primary mechanisms for proposing new
3263features, for collecting community input on an issue, and for
3264documenting the design decisions that have gone into Python. The PEP
3265author is responsible for building consensus within the community and
3266documenting dissenting opinions.
3267
3268The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003269
3270Augmented Assignment
3271--------------------
3272
3273This must have been the most-requested feature of the past years!
3274Eleven new assignment operators were added:
3275
Guido van Rossume905e952000-09-05 12:42:46 +00003276 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003277
3278For example,
3279
3280 A += B
3281
3282is similar to
3283
3284 A = A + B
3285
3286except that A is evaluated only once (relevant when A is something
3287like dict[index].attr).
3288
3289However, if A is a mutable object, A may be modified in place. Thus,
3290if A is a number or a string, A += B has the same effect as A = A+B
3291(except A is only evaluated once); but if a is a list, A += B has the
3292same effect as A.extend(B)!
3293
3294Classes and built-in object types can override the new operators in
3295order to implement the in-place behavior; the not-in-place behavior is
3296used automatically as a fallback when an object doesn't implement the
3297in-place behavior. For classes, the method name is derived from the
3298method name for the corresponding not-in-place operator by inserting
3299an 'i' in front of the name, e.g. __iadd__ implements in-place
3300__add__.
3301
3302Augmented assignment was implemented by Thomas Wouters.
3303
3304
3305List Comprehensions
3306-------------------
3307
3308This is a flexible new notation for lists whose elements are computed
3309from another list (or lists). The simplest form is:
3310
3311 [<expression> for <variable> in <sequence>]
3312
Guido van Rossum56db0952000-09-06 23:34:25 +00003313For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003314This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003315
3316You can also add a condition:
3317
3318 [<expression> for <variable> in <sequence> if <condition>]
3319
3320For example, [w for w in words if w == w.lower()] would yield the list
3321of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003322than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003323
3324You can also have nested for loops and more than one 'if' clause. For
3325example, here's a function that flattens a sequence of sequences::
3326
3327 def flatten(seq):
3328 return [x for subseq in seq for x in subseq]
3329
3330 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3331
3332This prints
3333
3334 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3335
3336List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003337Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003338
3339
3340Extended Import Statement
3341-------------------------
3342
3343Many people have asked for a way to import a module under a different
3344name. This can be accomplished like this:
3345
3346 import foo
3347 bar = foo
3348 del foo
3349
3350but this common idiom gets old quickly. A simple extension of the
3351import statement now allows this to be written as follows:
3352
3353 import foo as bar
3354
3355There's also a variant for 'from ... import':
3356
3357 from foo import bar as spam
3358
3359This also works with packages; e.g. you can write this:
3360
3361 import test.regrtest as regrtest
3362
3363Note that 'as' is not a new keyword -- it is recognized only in this
3364context (this is only possible because the syntax for the import
3365statement doesn't involve expressions).
3366
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003367Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003368
3369
3370Extended Print Statement
3371------------------------
3372
3373Easily the most controversial new feature, this extension to the print
3374statement adds an option to make the output go to a different file
3375than the default sys.stdout.
3376
3377For example, to write an error message to sys.stderr, you can now
3378write:
3379
3380 print >> sys.stderr, "Error: bad dog!"
3381
3382As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003383evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003384
3385 print >> None, "Hello world"
3386
3387is equivalent to
3388
3389 print "Hello world"
3390
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003391Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003392
3393
3394Optional Collection of Cyclical Garbage
3395---------------------------------------
3396
3397Python is now equipped with a garbage collector that can hunt down
3398cyclical references between Python objects. It's no replacement for
3399reference counting; in fact, it depends on the reference counts being
3400correct, and decides that a set of objects belong to a cycle if all
3401their reference counts can be accounted for from their references to
3402each other. This devious scheme was first proposed by Eric Tiedemann,
3403and brought to implementation by Neil Schemenauer.
3404
3405There's a module "gc" that lets you control some parameters of the
3406garbage collection. There's also an option to the configure script
3407that lets you enable or disable the garbage collection. In 2.0b1,
3408it's on by default, so that we (hopefully) can collect decent user
3409experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003410performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003411off by default in the final 2.0 release.
3412
3413
3414Smaller Changes
3415---------------
3416
3417A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3418map(None, seq1, seq2, ...) when the sequences have the same length;
3419i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3420the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003421zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003422
3423sys.version_info is a tuple (major, minor, micro, level, serial).
3424
3425Dictionaries have an odd new method, setdefault(key, default).
3426dict.setdefault(key, default) returns dict[key] if it exists; if not,
3427it sets dict[key] to default and returns that value. Thus:
3428
3429 dict.setdefault(key, []).append(item)
3430
3431does the same work as this common idiom:
3432
3433 if not dict.has_key(key):
3434 dict[key] = []
3435 dict[key].append(item)
3436
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003437There are two new variants of SyntaxError that are raised for
3438indentation-related errors: IndentationError and TabError.
3439
3440Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3441escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003442
3443The limits on the size of expressions and file in Python source code
3444have been raised from 2**16 to 2**32. Previous versions of Python
3445were limited because the maximum argument size the Python VM accepted
3446was 2**16. This limited the size of object constructor expressions,
3447e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3448limit was raised thanks to a patch by Charles Waldman that effectively
3449fixes the problem. It is now much more likely that you will be
3450limited by available memory than by an arbitrary limit in Python.
3451
3452The interpreter's maximum recursion depth can be modified by Python
3453programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3454limit is the maximum number of recursive calls that can be made by
3455Python code. The limit exists to prevent infinite recursion from
3456overflowing the C stack and causing a core dump. The default value is
34571000. The maximum safe value for a particular platform can be found
3458by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003459
3460New Modules and Packages
3461------------------------
3462
3463atexit - for registering functions to be called when Python exits.
3464
3465imputil - Greg Stein's alternative API for writing custom import
3466hooks.
3467
3468pyexpat - an interface to the Expat XML parser, contributed by Paul
3469Prescod.
3470
3471xml - a new package with XML support code organized (so far) in three
3472subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3473would fill a volume. There's a special feature whereby a
3474user-installed package named _xmlplus overrides the standard
3475xmlpackage; this is intended to give the XML SIG a hook to distribute
3476backwards-compatible updates to the standard xml package.
3477
3478webbrowser - a platform-independent API to launch a web browser.
3479
3480
Guido van Rossume905e952000-09-05 12:42:46 +00003481Changed Modules
3482---------------
3483
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003484array -- new methods for array objects: count, extend, index, pop, and
3485remove
3486
3487binascii -- new functions b2a_hex and a2b_hex that convert between
3488binary data and its hex representation
3489
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003490calendar -- Many new functions that support features including control
3491over which day of the week is the first day, returning strings instead
3492of printing them. Also new symbolic constants for days of week,
3493e.g. MONDAY, ..., SUNDAY.
3494
3495cgi -- FieldStorage objects have a getvalue method that works like a
3496dictionary's get method and returns the value attribute of the object.
3497
3498ConfigParser -- The parser object has new methods has_option,
3499remove_section, remove_option, set, and write. They allow the module
3500to be used for writing config files as well as reading them.
3501
3502ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003503optionally support the RFC 959 REST command.
3504
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003505gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003506
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003507httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3508the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003509
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003510locale -- implement getdefaultlocale for Win32 and Macintosh
3511
3512marshal -- no longer dumps core when marshaling deeply nested or
3513recursive data structures
3514
3515os -- new functions isatty, seteuid, setegid, setreuid, setregid
3516
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003517os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3518support under Unix.
3519
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003520os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003521
3522os.path -- fix semantics of os.path.commonprefix
3523
3524smtplib -- support for sending very long messages
3525
3526socket -- new function getfqdn()
3527
3528readline -- new functions to read, write and truncate history files.
3529The readline section of the library reference manual contains an
3530example.
3531
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003532select -- add interface to poll system call
3533
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003534shutil -- new copyfileobj function
3535
3536SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3537HTTP server.
3538
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003539Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003540
3541urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003542e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003543
3544whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003545
3546
3547Obsolete Modules
3548----------------
3549
3550None. However note that 1.6 made a whole slew of modules obsolete:
3551stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3552poly, zmod, strop, util, whatsound.
3553
3554
3555Changed, New, Obsolete Tools
3556----------------------------
3557
Tim Peters8b092332000-09-05 20:15:25 +00003558None.
Guido van Rossume905e952000-09-05 12:42:46 +00003559
3560
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003561C-level Changes
3562---------------
3563
3564Several cleanup jobs were carried out throughout the source code.
3565
3566All C code was converted to ANSI C; we got rid of all uses of the
3567Py_PROTO() macro, which makes the header files a lot more readable.
3568
3569Most of the portability hacks were moved to a new header file,
3570pyport.h; several other new header files were added and some old
3571header files were removed, in an attempt to create a more rational set
3572of header files. (Few of these ever need to be included explicitly;
3573they are all included by Python.h.)
3574
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003575Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003576and Win64, especially for the new Intel Itanium processor. Mick also
3577added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003578
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003579The C APIs to return an object's size have been update to consistently
3580use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3581previous versions, the abstract interfaces used PyXXX_Length and the
3582concrete interfaces used PyXXX_Size. The old names,
3583e.g. PyObject_Length, are still available for backwards compatibility
3584at the API level, but are deprecated.
3585
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003586The PyOS_CheckStack function has been implemented on Windows by
3587Fredrik Lundh. It prevents Python from failing with a stack overflow
3588on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003589
3590The GC changes resulted in creation of two new slots on object,
3591tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003592the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003593
3594The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003595C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003596
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003597PyErr_Format has been updated to automatically calculate the size of
3598the buffer needed to hold the formatted result string. This change
3599prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003600
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003601New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003602
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003603PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3604that are the same as their non-Ex counterparts except they take an
3605extra flag argument that tells them to close the file when done.
3606
3607XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003608
Tim Peters8b092332000-09-05 20:15:25 +00003609
3610Windows Changes
3611---------------
3612
3613New popen2/popen3/peopen4 in os module (see Changed Modules above).
3614
3615os.popen is much more usable on Windows 95 and 98. See Microsoft
3616Knowledge Base article Q150956. The Win9x workaround described there
3617is implemented by the new w9xpopen.exe helper in the root of your
3618Python installation. Note that Python uses this internally; it is not
3619a standalone program.
3620
3621Administrator privileges are no longer required to install Python
3622on Windows NT or Windows 2000. If you have administrator privileges,
3623Python's registry info will be written under HKEY_LOCAL_MACHINE.
3624Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003625under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003626uses of Python, but will prevent some advanced uses from working
3627(for example, running a Python script as an NT service, or possibly
3628from CGI).
3629
3630[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3631installer; instead, it installs the needed Tcl/Tk files directly in the
3632Python directory. If you already have a Tcl/Tk installation, this
3633wastes some disk space (about 4 Megs) but avoids problems with
3634conflicting Tcl/Tk installations, and makes it much easier for Python
3635to ensure that Tcl/Tk can find all its files.
3636
3637[This was new in 1.6] The Windows installer now installs by default in
3638\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3639
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003640
3641Updates to the changes between 1.5.2 and 1.6
3642--------------------------------------------
3643
3644The 1.6 NEWS file can't be changed after the release is done, so here
3645is some late-breaking news:
3646
3647New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3648and changes to getlocale() and setlocale().
3649
3650The new module is now enabled per default.
3651
3652It is not true that the encodings codecs cannot be used for normal
3653strings: the string.encode() (which is also present on 8-bit strings
3654!) allows using them for 8-bit strings too, e.g. to convert files from
3655cp1252 (Windows) to latin-1 or vice-versa.
3656
3657Japanese codecs are available from Tamito KAJIYAMA:
3658http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3659
3660
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003661======================================================================