blob: 0a1ce88e11ba680e1f1550e7e10249291da0d8ab [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
Mark Hammondc0e35152002-07-16 01:32:30 +00009- Ctrl+C handling on Windows has been made more consistent with
10 other platforms. KeyboardInterrupt can now reliably be caught,
11 and Ctrl+C at an interative prompt no longer terminates the
12 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
13 interrupt time.sleep() in the main thread, and any child processes
14 created via the popen family are also interrupted (as generally
15 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
16
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000017- Slices and repetitions of buffer objects now consistently return
18 a string. Formerly, strings would be returned most of the time,
19 but a buffer object would be returned when the repetition count
20 was one or when the slice range was all inclusive.
21
Guido van Rossumc7c36502002-06-21 01:29:25 +000022- The __slots__ variable can now mention "private" names, and the
23 right thing will happen (e.g. __slots__ = ["__foo"]).
24
Walter Dörwald3430d702002-06-17 10:43:59 +000025- Unicode objects in sys.path are no longer ignored but treated
26 as directory names.
27
Guido van Rossum9562bcf2002-06-14 21:31:18 +000028- The built-ins slice() and buffer() are now callable types. The
29 types classobj (formerly class), code, function, instance, and
30 instancemethod (formerly instance-method), which have no built-in
31 names but are accessible through the types module, are now also
32 callable. The type dict-proxy is renamed to dictproxy.
33
Neal Norwitz1f68fc72002-06-14 00:50:42 +000034- Fixed string.startswith and string.endswith builtin methods
35 so they accept negative indices. [SF bug 493951]
36
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000037- Fixed a bug with a continue inside a try block and a yield in the
38 finally clause. [SF bug 567538]
39
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000040- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000041 with a third "stride" parameter. For example, "hello world"[::-1]
42 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000043
Guido van Rossum9f7549b2002-06-10 21:39:42 +000044- Cycles going through the __class__ link of a new-style instance are
45 now detected by the garbage collector.
46
Guido van Rossum9923ffe2002-06-04 19:52:53 +000047- Classes using __slots__ are now properly garbage collected.
48 [SF bug 519621]
49
50- Tightened the __slots__ rules: a slot name must be a valid Python
51 identifier.
52
Guido van Rossum2e4e0262002-06-04 05:58:34 +000053- The constructor for the module type now requires a name argument and
54 takes an optional docstring argument. Previously, this constructor
55 ignored its arguments. As a consequence, deriving a class from a
56 module (not from the module type) is now illegal; previously this
57 created an unnamed module, just like invoking the module type did.
58 [SF bug 563060]
59
Neal Norwitzd68f5172002-05-29 15:54:55 +000060- A new warning PendingDeprecationWarning was added to provide
61 direction on features which are in the process of being deprecated.
62 The warning will not be printed by default. To see the pending
63 deprecations, use -Walways::PendingDeprecationWarning::
64 as a command line option or warnings.filterwarnings() in code.
65
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000066- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000067 for 'str' and 'unicode', and can be used instead of
68 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000069 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000070 is an abstract base class and cannot be instantiated directly.
71
Fred Draked0ba6362002-05-02 21:28:26 +000072- Deprecated features of xrange objects have been removed as
73 promised. The start, stop, and step attributes and the tolist()
74 method no longer exist. xrange repetition and slicing have been
75 removed.
76
Guido van Rossum7dab2422002-04-26 19:40:56 +000077- New builtin function enumerate(x), from PEP 279. Example:
78 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
79 The argument can be an arbitrary iterable object.
80
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000081- The assert statement no longer tests __debug__ at runtime. This means
82 that assert statements cannot be disabled by assigning a false value
83 to __debug__.
84
Walter Dörwald068325e2002-04-15 13:36:47 +000085- A method zfill() was added to str and unicode, that fills a numeric
86 string to the left with zeros. For example,
87 "+123".zfill(6) -> "+00123".
88
Guido van Rossum862fe3c2002-04-15 12:36:47 +000089- Complex numbers supported divmod() and the // and % operators, but
90 these make no sense. Since this was documented, they're being
91 deprecated now.
92
Guido van Rossum26dd8302002-04-26 20:11:29 +000093- String and unicode methods lstrip(), rstrip() and strip() now take
94 an optional argument that specifies the characters to strip. For
95 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000096
Guido van Rossumc69343b2002-04-12 19:22:48 +000097- Added a new dict method pop(key). This removes and returns the
98 value corresponding to key. [SF patch #539949]
99
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000100- Changed new-style class instantiation so that when C's __new__
101 method returns something that's not a C instance, its __init__ is
102 not called. [SF bug #537450]
103
Guido van Rossum181e41a2002-04-06 00:23:25 +0000104- Fixed super() to work correctly with class methods. [SF bug #535444]
105
Guido van Rossum47834462002-04-04 15:21:33 +0000106- A new built-in type, bool, has been added, as well as built-in
107 names for its two values, True and False. Comparisons and sundry
108 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000109 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000110 is backward compatible.
111
Guido van Rossum95b62a62002-03-29 01:07:24 +0000112- Fixed two bugs reported as SF #535905: under certain conditions,
113 deallocating a deeply nested structure could cause a segfault in the
114 garbage collector, due to interaction with the "trashcan" code;
115 access to the current frame during destruction of a local variable
116 could access a pointer to freed memory.
117
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000118- The optional object allocator ("pymalloc") has been enabled by
119 default. The recommended practice for memory allocation and
120 deallocation has been streamlined. A header file is included,
121 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
122 and lets them use the same API with Python versions from 1.5.2
123 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000124
Guido van Rossum8c842552002-03-14 23:05:54 +0000125- If you try to pickle an instance of a class that has __slots__ but
126 doesn't define or override __getstate__, a TypeError is now raised.
127 This is done by adding a bozo __getstate__ to the class that always
128 raises TypeError. (Before, this would appear to be pickled, but the
129 state of the slots would be lost.)
130
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000131- PyErr_Display will provide file and line information for all exceptions
132 that have an attribute print_file_and_line, not just SyntaxErrors.
133
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000134- The UTF-8 codec will now encode and decode Unicode surrogates
135 correctly and without raising exceptions for unpaired ones.
136
Neal Norwitz649b7592002-01-01 19:07:13 +0000137- file.xreadlines() now raises a ValueError if the file is closed:
138 Previously, an xreadlines object was returned which would raise
139 a ValueError when the xreadlines.next() method was called.
140
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000141- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000142 An exception will now be raised if more than one argument is used.
143
Tim Petersaf8446f2001-12-21 21:36:50 +0000144Extension modules
145
Guido van Rossum79f0a102002-07-23 03:32:08 +0000146- The strptime function in the time module is now always available (a
147 Python implementation is used when the C library doesn't define it).
148
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000149- The 'new' module is no longer an extension, but a Python module that
150 only exists for backwards compatibility. Its contents are no longer
151 functions but callable type objects.
152
Tim Peters81b92512002-04-29 01:37:32 +0000153- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000154 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000155 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000156
Martin v. Löwis606edc12002-06-13 21:09:11 +0000157- posix.killpg, posix.mknod, and posix.getpgid have been added where
158 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000159
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000160- The locale module now exposes the C library's gettext interface.
161
Tim Petersfbf74f22002-03-14 19:06:01 +0000162- A security hole ("double free") was found in zlib-1.1.3, a popular
163 third party compression library used by some Python modules. The
164 hole was quickly plugged in zlib-1.1.4, and the Windows build of
165 Python now ships with zlib-1.1.4.
166
Martin v. Löwis688357e2002-04-08 21:28:20 +0000167- pwd, grp, and resource return enhanced tuples now, with symbolic
168 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000169
Martin v. Löwis99866332002-03-01 10:27:01 +0000170- array.array is now a type object. A new format character
171 'u' indicates Py_UNICODE arrays. For those, .tounicode and
172 .fromunicode methods are available. Arrays now support __iadd__
173 and __imul__.
174
Neal Norwitze790eae2002-01-01 21:14:12 +0000175- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000176 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
177 is called.
178
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000179- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
180 been added where available.
181
Tim Petersaf8446f2001-12-21 21:36:50 +0000182Library
183
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000184- New encoding for the Palm OS character set: palmos.
185
Tim Peters943382c2002-07-07 03:59:34 +0000186- binascii.crc32() and the zipfile module had problems on some 64-bit
187 platforms. These have been fixed. On a platform with 8-byte C longs,
188 crc32() now returns a signed-extended 4-byte result, so that its value
189 as a Python int is equal to the value computed a 32-bit platform.
190
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000191- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
192 argument.
193
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000194- Some fixes in the copy module: when an object is copied through its
195 __reduce__ method, there was no check for a __setstate__ method on
196 the result [SF patch 565085]; deepcopy should treat instances of
197 custom metaclasses the same way it treats instances of type 'type'
198 [SF patch 560794].
199
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000200- Sockets now support timeout mode. After s.settimeout(T), where T is
201 a float expressing seconds, subsequent operations raise an exception
202 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000203 mode, use s.settimeout(None). There's also a module function,
204 socket.setdefaulttimeout(T), which sets the default for all sockets
205 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000206
207- getopt.gnu_getopt was added. This supports GNU-style option
208 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000209
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000210- Stop using strings for exceptions. String objects used for
211 exceptions are now classes deriving from Exception. The objects
212 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
213 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000214
Walter Dörwald474458d2002-06-04 15:16:29 +0000215- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
216 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
217 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
218 big endian systems were added to the codecs module. The old names
219 BOM32_* and BOM64_* were off by a factor of 2.
220
Guido van Rossumf9257822002-06-18 20:43:18 +0000221- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000222
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000223- ftplib.retrlines() now tests for callback is None rather than testing
224 for False. Was causing an error when given a callback object which
225 was callable but also returned len() as zero. The change may
226 create new breakage if the caller relied on the undocumented behavior
227 and called with callback set to [] or some other False value not
228 identical to None.
229
Tim Peters46c04e12002-05-05 20:40:00 +0000230- random.gauss() uses a piece of hidden state used by nothing else,
231 and the .seed() and .whseed() methods failed to reset it. In other
232 words, setting the seed didn't completely determine the sequence of
233 results produced by random.gauss(). It does now. Programs repeatedly
234 mixing calls to a seed method with calls to gauss() may see different
235 results now.
236
Fred Drake7f781c92002-05-01 20:33:53 +0000237- The pickle.Pickler class grew a clear_memo() method to mimic that
238 provided by cPickle.Pickler.
239
Tim Peters81b92512002-04-29 01:37:32 +0000240- difflib's SequenceMatcher class now does a dynamic analysis of
241 which elements are so frequent as to constitute noise. For
242 comparing files as sequences of lines, this generally works better
243 than the IS_LINE_JUNK function, and function ndiff's linejunk
244 argument defaults to None now as a result. A happy benefit is
245 that SequenceMatcher may run much faster now when applied
246 to large files with many duplicate lines (for example, C program
247 text with lots of repeated "}" and "return NULL;" lines).
248
Guido van Rossum256705b2002-04-23 13:29:43 +0000249- New Text.dump() method in Tkinter module.
250
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000251- New distutils commands for building packagers were added to
252 support pkgtool on Solaris and swinstall on HP-UX.
253
254- distutils now has a new abstract binary packager base class
255 command/bdist_packager, which simplifies writing packagers.
256 This will hopefully provide the missing bits to encourage
257 people to submit more packagers, e.g. for Debian, FreeBSD
258 and other systems.
259
Guido van Rossumf9257822002-06-18 20:43:18 +0000260- The UTF-16, -LE and -BE stream readers now raise a
261 NotImplementedError for all calls to .readline(). Previously, they
262 used to just produce garbage or fail with an encoding error --
263 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 +0000264 work well with these.
265
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000266- compileall now supports quiet operation.
267
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000268- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000269 connections.
270
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000271- socket module: the SSL support was broken out of the main
272 _socket module C helper and placed into a new _ssl helper
273 which now gets imported by socket.py if available and working.
274
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000275- encodings package: added aliases for all supported IANA character
276 sets
277
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000278- ftplib: to safeguard the user's privacy, anonymous login will use
279 "anonymous@" as default password, rather than the real user and host
280 name.
281
Fred Drake36736122002-01-10 13:50:31 +0000282- webbrowser: tightened up the command passed to os.system() so that
283 arbitrary shell code can't be executed because a bogus URL was
284 passed in.
285
Tim Peters11bd9942002-02-01 00:52:29 +0000286- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000287 gettext.find an optional all argument. Translations will now fallback
288 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000289
Martin v. Löwis9668b932002-01-12 11:27:42 +0000290- distutils bdist commands now offer a --skip-build option.
291
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000292- warnings.warn now accepts a Warning instance as first argument.
293
Fred Drakefed7e852002-04-04 19:36:15 +0000294- The xml.sax.expatreader.ExpatParser class will no longer create
295 circular references by using itself as the locator that gets passed
296 to the content handler implementation. [SF bug #535474]
297
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000298- The email.Parser.Parser class now properly parses strings regardless
299 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
300 or CRLF). Also, the Header class's constructor default arguments
301 has changed slightly so that an explicit maxlinelen value is always
302 honored.
303
Tim Petersaf8446f2001-12-21 21:36:50 +0000304Tools/Demos
305
Marc-André Lemburg46260092002-04-04 16:17:11 +0000306- freeze.py now produces binaries which can import shared modules,
307 unlike before when this failed due to missing symbol exports in
308 the generated binary.
309
Tim Petersaf8446f2001-12-21 21:36:50 +0000310Build
311
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000312- The public Python C API will generally be declared using PyAPI_FUNC
313 and PyAPI_DATA macros, while Python extension module init functions
314 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
315 are deprecated.
316
Tim Petersc6a3ff62002-07-08 22:11:52 +0000317- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
318 get into infinite loops, when a new-style class got garbage-collected.
319 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
320 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
321 COUNT_ALLOCS is not enabled by default, in either release or debug
322 builds, and that new-style classes are immortal only in COUNT_ALLOCS
323 builds.
324
Tim Peters943382c2002-07-07 03:59:34 +0000325- Compiling out the cyclic garbage collector is no longer an option.
326 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
327 that it's always defined (for the benefit of any extension modules
328 that may be conditionalizing on it). A bonus is that any extension
329 type participating in cyclic gc can choose to participate in the
330 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
331 to require editing the core to teach the trashcan mechanism about the
332 new type.
333
Tim Peters1de41bf2002-07-03 03:31:20 +0000334- Accoring to Annex F of the current C standard,
335
336 The Standard C macro HUGE_VAL and its float and long double analogs,
337 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
338 positive infinities.
339
340 Python only uses the double HUGE_VAL, and only to #define its own symbol
341 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
342 pyport.h used to try to worm around that, but the workarounds triggered
343 other bugs on other platforms, so we gave up. If your platform defines
344 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
345 that works on your platform. The only instance of this I'm sure about
346 is on an unknown subset of Cray systems, described here:
347
348 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
349
350 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
351
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000352- The configure option --without-doc-strings can be used to remove the
353 doc strings from the builtin functions and modules; this reduces the
354 size of the executable.
355
Tim Peters639295f2002-04-21 07:30:30 +0000356- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
357 say how or when to configure it, or how to turn it off.
358
Martin v. Löwis1142de32002-03-29 16:28:31 +0000359- On Unix, a shared libpython2.3.so can be created with --enable-shared.
360
Tim Peters8deda702002-03-30 10:06:07 +0000361- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
362 preprocessor symbols were eliminated. The internal decisions they
363 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000364
Fred Drake7d28b732002-05-02 21:17:00 +0000365- The tools used to build the documentation now work under Cygwin as
366 well as Unix.
367
Skip Montanaro57454e52002-06-14 20:30:31 +0000368- The bsddb and dbm module builds have been changed to try and avoid version
369 skew problems and disable linkage with Berkeley DB 1.85 unless the
370 installer knows what s/he's doing. See the section on building these
371 modules in the README file for details.
372
Tim Petersaf8446f2001-12-21 21:36:50 +0000373C API
374
Tim Peters7c321a82002-07-09 02:57:01 +0000375- Py_FatalError() is now declared as taking a const char* argument. It
376 was previously declared without const. This should not affect working
377 code.
378
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000379- Added new macro PySequence_ITEM(o, i) that directly calls
380 sq_item without rechecking that o is a sequence and without
381 adjusting for negative indices.
382
Fred Draked0ba6362002-05-02 21:28:26 +0000383- PyRange_New() now raises ValueError if the fourth argument is not 1.
384 This is part of the removal of deprecated features of the xrange
385 object.
386
Guido van Rossum517c7d42002-04-26 02:49:14 +0000387- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
388 coercion if both arguments have the same type but this type has the
389 CHECKTYPES flag set. This is to better support proxies.
390
Neil Schemenauer9344b142002-04-12 23:00:08 +0000391- The type of tp_free has been changed from "void (*)(PyObject *)" to
392 "void (*)(void *)".
393
394- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
395
Guido van Rossum0986d822002-04-08 01:38:42 +0000396- A type can now inherit its metatype from its base type. Previously,
397 when PyType_Ready() was called, if ob_type was found to be NULL, it
398 was always set to &PyType_Type; now it is set to base->ob_type,
399 where base is tp_base, defaulting to &PyObject_Type.
400
401- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
402
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000403- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000404
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000405- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000406 without going through the buffer API.
407
Martin v. Löwis7198a522002-01-01 19:59:11 +0000408- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
409
Tim Peters10a3bb52001-12-25 19:07:38 +0000410- An old #define of ANY as void has been removed from pyport.h. This
411 hasn't been used since Python's pre-ANSI days, and the #define has
412 been marked as obsolete since then. SF bug 495548 says it created
413 conflicts with other packages, so keeping it around wasn't harmless.
414
Tim Petersaf8446f2001-12-21 21:36:50 +0000415- Because Python's magic number scheme broke on January 1st, we decided
416 to stop Python development. Thanks for all the fish!
417
Tim Petersfb05db22002-03-11 00:24:00 +0000418- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000419 scheme to a new one. See Python/import.c for details.
420
Tim Petersaf8446f2001-12-21 21:36:50 +0000421New platforms
422
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000423- AtheOS is now supported.
424
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000425- GNU/Hurd is now supported.
426
Tim Petersaf8446f2001-12-21 21:36:50 +0000427Tests
428
429Windows
430
Tim Peters08e72952002-04-16 20:48:01 +0000431- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
432 of that has been fixed in the installer (disabled Wise's "delete in-
433 use files" uninstall option).
434
Guido van Rossum181e41a2002-04-06 00:23:25 +0000435- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
436
Tim Peters33187922002-04-04 20:02:04 +0000437- The installer now installs Start menu shortcuts under (the local
438 equivalent of) "All Users" when doing an Admin install.
439
Tim Petersfb05db22002-03-11 00:24:00 +0000440- file.truncate([newsize]) now works on Windows for all newsize values.
441 It used to fail if newsize didn't fit in 32 bits, reflecting a
442 limitation of MS _chsize (which is no longer used).
443
Tim Petersab034fa2002-02-01 11:27:43 +0000444- os.waitpid() is now implemented for Windows, and can be used to block
445 until a specified process exits. This is similar to, but not exactly
446 the same as, os.waitpid() on POSIX systems. If you're waiting for
447 a specific process whose pid was obtained from one of the spawn()
448 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000449 See the docs for details. The docs were changed to clarify that
450 spawn functions return, and waitpid requires, a process handle on
451 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000452
Tim Peters11bd9942002-02-01 00:52:29 +0000453- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000454 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000455 to a nasty problem: before 2.3, if you got a temp file on Windows, it
456 got wrapped in an object whose close() method first closed the
457 underlying file, then deleted the file. This usually worked fine.
458 However, the spawn family of functions on Windows create (at a low C
459 level) the same set of open files in the spawned process Q as were
460 open in the spawning process P. If a temp file f was among them, then
461 doing f.close() in P first closed P's C-level file handle on f, but Q's
462 C-level file handle on f remained open, so the attempt in P to delete f
463 blew up with a "Permission denied" error (Windows doesn't allow
464 deleting open files). This was surprising, subtle, and difficult to
465 work around.
466
467- The os module now exports all the symbolic constants usable with the
468 low-level os.open() on Windows: the new constants in 2.3 are
469 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
470 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
471 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
472 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
473 (so specify both if you want both; note that neither is useful unless
474 specified with O_CREAT too).
475
Tim Petersaf8446f2001-12-21 21:36:50 +0000476Mac
477
478
Tim Peters909c0912001-12-14 23:16:18 +0000479What's New in Python 2.2 final?
480Release date: 21-Dec-2001
481===============================
482
483Type/class unification and new-style classes
484
Barry Warsaw52acb492001-12-21 20:04:22 +0000485- pickle.py, cPickle: allow pickling instances of new-style classes
486 with a custom metaclass.
487
Tim Peters909c0912001-12-14 23:16:18 +0000488Core and builtins
489
Barry Warsaw52acb492001-12-21 20:04:22 +0000490- weakref proxy object: when comparing, unwrap both arguments if both
491 are proxies.
492
Tim Peters909c0912001-12-14 23:16:18 +0000493Extension modules
494
Barry Warsaw52acb492001-12-21 20:04:22 +0000495- binascii.b2a_base64(): fix a potential buffer overrun when encoding
496 very short strings.
497
498- cPickle: the obscure "fast" mode was suspected of causing stack
499 overflows on the Mac. Hopefully fixed this by setting the recursion
500 limit much smaller. If the limit is too low (it only affects
501 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
502 when compiling cPickle.c (or in pyconfig.h).
503
Tim Peters909c0912001-12-14 23:16:18 +0000504Library
505
Barry Warsaw52acb492001-12-21 20:04:22 +0000506- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
507 close or delete time).
508
509- rfc822.py: fixed a bug where the address '<>' was converted to None
510 instead of an empty string (also fixes the email.Utils module).
511
512- xmlrpclib.py: version 1.0.0; uses precision for doubles.
513
514- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000515 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000516
Tim Peters909c0912001-12-14 23:16:18 +0000517Tools/Demos
518
519Build
520
521C API
522
523New platforms
524
525Tests
526
527Windows
528
Barry Warsaw52acb492001-12-21 20:04:22 +0000529- distutils package: fixed broken Windows installers (bdist_wininst).
530
531- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
532 instances are deleted at process exit time.
533
534- socket.py: prevent mysterious warnings when socket instances are
535 deleted at process exit time.
536
537- posixmodule.c: fix a Windows crash with stat() of a filename ending
538 in backslash.
539
Tim Peters909c0912001-12-14 23:16:18 +0000540Mac
541
Barry Warsaw52acb492001-12-21 20:04:22 +0000542- The Carbon toolbox modules have been upgraded to Universal Headers
543 3.4, and experimental CoreGraphics and CarbonEvents modules have
544 been added. All only for framework-enabled MacOSX.
545
Tim Peters909c0912001-12-14 23:16:18 +0000546
Tim Peters6272dfd2001-12-13 19:34:00 +0000547What's New in Python 2.2c1?
548Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000549===========================
550
551Type/class unification and new-style classes
552
Barry Warsaw06557452001-12-14 20:47:12 +0000553- Guido's tutorial introduction to the new type/class features has
554 been extensively updated. See
555
556 http://www.python.org/2.2/descrintro.html
557
558 That remains the primary documentation in this area.
559
Guido van Rossum33bab012001-12-05 22:45:48 +0000560- Fixed a leak: instance variables declared with __slots__ were never
561 deleted!
562
Guido van Rossum4b800852001-12-03 00:54:52 +0000563- The "delete attribute" method of descriptor objects is called
564 __delete__, not __del__. In previous releases, it was mistakenly
565 called __del__, which created an unfortunate overloading condition
566 with finalizers. (The "get attribute" and "set attribute" methods
567 are still called __get__ and __set__, respectively.)
568
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000569- Some subtle issues with the super built-in were fixed:
570
571 (a) When super itself is subclassed, its __get__ method would still
572 return an instance of the base class (i.e., of super).
573
574 (b) super(C, C()).__class__ would return C rather than super. This
575 is confusing. To fix this, I decided to change the semantics of
576 super so that it only applies to code attributes, not to data
577 attributes. After all, overriding data attributes is not
578 supported anyway.
579
580 (c) The __get__ method didn't check whether the argument was an
581 instance of the type used in creation of the super instance.
582
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000583- Previously, hash() of an instance of a subclass of a mutable type
584 (list or dictionary) would return some value, rather than raising
585 TypeError. This has been fixed. Also, directly calling
586 dict.__hash__ and list.__hash__ now raises the same TypeError
587 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000588
Guido van Rossumd331cb52001-12-05 19:46:42 +0000589- New-style objects now support deleting their __dict__. This is for
590 all intents and purposes equivalent to assigning a brand new empty
591 dictionary, but saves space if the object is not used further.
592
Tim Petersb3c9af12001-11-17 00:21:57 +0000593Core and builtins
594
Tim Peters3caca232001-12-06 06:23:26 +0000595- -Qnew now works as documented in PEP 238: when -Qnew is passed on
596 the command line, all occurrences of "/" use true division instead
597 of classic division. See the PEP for details. Note that "all"
598 means all instances in library and 3rd-party modules, as well as in
599 your own code. As the PEP says, -Qnew is intended for use only in
600 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000601 Note that test_coercion.py in the standard Python test suite fails
602 under -Qnew; this is expected, and won't be repaired until true
603 division becomes the default (in the meantime, test_coercion is
604 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000605
Fred Drake6c01e252001-12-14 17:08:12 +0000606- complex() now only allows the first argument to be a string
607 argument, and raises TypeError if either the second arg is a string
608 or if the second arg is specified when the first is a string.
609
Tim Petersb3c9af12001-11-17 00:21:57 +0000610Extension modules
611
Martin v. Löwis560da622001-11-24 09:24:51 +0000612- gc.get_referents was renamed to gc.get_referrers.
613
Tim Petersb3c9af12001-11-17 00:21:57 +0000614Library
615
Tim Peters25059d32001-12-07 20:35:43 +0000616- Functions in the os.spawn() family now release the global interpreter
617 lock around calling the platform spawn. They should always have done
618 this, but did not before 2.2c1. Multithreaded programs calling
619 an os.spawn function with P_WAIT will no longer block all Python threads
620 until the spawned program completes. It's possible that some programs
621 relies on blocking, although more likely by accident than by design.
622
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000623- webbrowser defaults to netscape.exe on OS/2 now.
624
Martin v. Löwis652e1912001-11-25 14:50:56 +0000625- Tix.ResizeHandle exposes detach_widget, hide, and show.
626
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000627- The charset alias windows_1252 has been added.
628
Barry Warsaw06557452001-12-14 20:47:12 +0000629- types.StringTypes is a tuple containing the defined string types;
630 usually this will be (str, unicode), but if Python was compiled
631 without Unicode support it will be just (str,).
632
633- The pulldom and minidom modules were synchronized to PyXML.
634
Tim Petersb3c9af12001-11-17 00:21:57 +0000635Tools/Demos
636
Barry Warsaw06557452001-12-14 20:47:12 +0000637- A new script called Tools/scripts/google.py was added, which fires
638 off a search on Google.
639
Tim Petersb3c9af12001-11-17 00:21:57 +0000640Build
641
Barry Warsaw06557452001-12-14 20:47:12 +0000642- Note that release builds of Python should arrange to define the
643 preprocessor symbol NDEBUG on the command line (or equivalent).
644 In the 2.2 pre-release series we tried to define this by magic in
645 Python.h instead, but it proved to cause problems for extension
646 authors. The Unix, Windows and Mac builds now all define NDEBUG in
647 release builds via cmdline (or equivalent) instead. Ports to
648 other platforms should do likewise.
649
Jack Jansen1999ef42001-12-06 21:47:20 +0000650- It is no longer necessary to use --with-suffix when building on a
651 case-insensitive file system (such as Mac OS X HFS+). In the build
652 directory an extension is used, but not in the installed python.
653
Tim Petersb3c9af12001-11-17 00:21:57 +0000654C API
655
Tim Petersf582b822001-12-11 18:51:08 +0000656- New function PyDict_MergeFromSeq2() exposes the builtin dict
657 constructor's logic for updating a dictionary from an iterable object
658 producing key-value pairs.
659
Tim Peterscffed4b2001-11-29 03:26:37 +0000660- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000661 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000662 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
663 dump core in some bad cases. This has been repaired. As a result,
664 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
665 previously went unchallenged.
666
Tim Petersb3c9af12001-11-17 00:21:57 +0000667New platforms
668
669Tests
670
671Windows
672
673Mac
674
Jack Jansenffa260f2001-12-06 21:14:00 +0000675- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
676 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000677
Barry Warsaw06557452001-12-14 20:47:12 +0000678- Changed logic for finding python home in Mac OS X framework Pythons.
679 Now sys.executable points to the executable again, in stead of to
680 the shared library. The latter is used only for locating the python
681 home.
682
683
Tim Peters84362bc2001-10-19 17:55:30 +0000684What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000685Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000686===========================
687
688Type/class unification and new-style classes
689
Guido van Rossum3d27df02001-11-15 20:27:54 +0000690- Multiple inheritance mixing new-style and classic classes in the
691 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000692
693 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000694 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000695
696 The MRO (method resolution order) for each base class is respected
697 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000698 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000699 This needs to be documented.
700
Tim Petersa427a2b2001-10-29 22:25:45 +0000701- The new builtin dictionary() constructor, and dictionary type, have
702 been renamed to dict. This reflects a decade of common usage.
703
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000704- dict() now accepts an iterable object producing 2-sequences. For
705 example, dict(d.items()) == d for any dictionary d. The argument,
706 and the elements of the argument, can be any iterable objects.
707
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000708- New-style classes can now have a __del__ method, which is called
709 when the instance is deleted (just like for classic classes).
710
Guido van Rossum12d955c2001-10-26 14:56:06 +0000711- Assignment to object.__dict__ is now possible, for objects that are
712 instances of new-style classes that have a __dict__ (unless the base
713 class forbids it).
714
Guido van Rossumc8e56452001-10-22 00:43:43 +0000715- Methods of built-in types now properly check for keyword arguments
716 (formerly these were silently ignored). The only built-in methods
717 that take keyword arguments are __call__, __init__ and __new__.
718
Guido van Rossum86443212001-10-27 22:28:54 +0000719- The socket function has been converted to a type; see below.
720
Tim Peters84362bc2001-10-19 17:55:30 +0000721Core and builtins
722
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000723- Assignment to __debug__ raises SyntaxError at compile-time. This
724 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000725 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000726
Guido van Rossum12d955c2001-10-26 14:56:06 +0000727- Clarified the error messages for unsupported operands to an operator
728 (like 1 + '').
729
Tim Peters84362bc2001-10-19 17:55:30 +0000730Extension modules
731
Tim Peters5ebfd362001-11-13 23:11:19 +0000732- mmap has a new keyword argument, "access", allowing a uniform way for
733 both Windows and Unix users to create read-only, write-through and
734 copy-on-write memory mappings. This was previously possible only on
735 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000736 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000737 platforms. Thanks to Jay T Miller for repairing this!
738
Tim Peters169ded02001-11-03 19:57:21 +0000739- By default, the gc.garbage list now contains only those instances in
740 unreachable cycles that have __del__ methods; in 2.1 it contained all
741 instances in unreachable cycles. "Instances" here has been generalized
742 to include instances of both new-style and old-style classes.
743
Guido van Rossum12d955c2001-10-26 14:56:06 +0000744- The socket module defines a new method for socket objects,
745 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000746 send() until all data has been sent. Also, the socket function has
747 been converted to a subclassable type, like list and tuple (etc.)
748 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000749
750- Various bugfixes to the curses module. There is now a test suite
751 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000752
Guido van Rossum692adf12001-10-30 03:03:03 +0000753- binascii.b2a_base64 no longer places an arbitrary restriction of 57
754 bytes on its input.
755
Tim Peters84362bc2001-10-19 17:55:30 +0000756Library
757
Tim Peters5ebfd362001-11-13 23:11:19 +0000758- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000759 convenience function.
760
Tim Peters75335872001-11-03 19:35:43 +0000761- Symbolic group names in regular expressions must be unique. For
762 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
763 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000764 Python 2.2 detects this error at regexp compilation time;
765 previously, the error went undetected, and results were
766 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
767 pattern.subn() methods have been rewritten in C. Also, an
768 experimental function/method finditer() has been added, which works
769 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000770
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000771- Tix exposes more commands through the classes DirSelectBox,
772 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
773 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
774 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
775
Tim Peters98791af2001-10-23 01:59:54 +0000776- Traceback objects are now scanned by cyclic garbage collection, so
777 cycles created by casual use of sys.exc_info() no longer cause
778 permanent memory leaks (provided garbage collection is enabled).
779
Guido van Rossum49192142001-10-24 20:51:44 +0000780- os.extsep -- a new variable needed by the RISCOS support. It is the
781 separator used by extensions, and is '.' on all platforms except
782 RISCOS, where it is '/'. There is no need to use this variable
783 unless you have a masochistic desire to port your code to RISCOS.
784
Barry Warsaw012852b2001-11-16 16:17:27 +0000785- mimetypes.py has optional support for non-standard, but commonly
786 found types. guess_type() and guess_extension() now accept an
787 optional `strict' flag, defaulting to true, which controls whether
788 recognize non-standard types or not. A few non-standard types we
789 know about have been added. Also, when run as a script, there are
790 new -l and -e options.
791
792- statcache is now deprecated.
793
794- email.Utils.formatdate() now produces the preferred RFC 2822 style
795 dates with numeric timezones (it used to produce obsolete dates
796 hard coded to "GMT" timezone). An optional `localtime' flag is
797 added to produce dates in the local timezone, with daylight savings
798 time properly taken into account.
799
800- In pickle and cPickle, instead of masking errors in load() by
801 transforming them into SystemError, we let the original exception
802 propagate out. Also, implement support for __safe_for_unpickling__
803 in pickle, as it already was supported in cPickle.
804
Tim Peters84362bc2001-10-19 17:55:30 +0000805Tools/Demos
806
807Build
808
Barry Warsaw012852b2001-11-16 16:17:27 +0000809- The dbm module is built using libdb1 if available. The bsddb module
810 is built with libdb3 if available.
811
812- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
813
Tim Peters84362bc2001-10-19 17:55:30 +0000814C API
815
Tim Peters1fc240e2001-10-26 05:06:50 +0000816- New function PySequence_Fast_GET_SIZE() returns the size of a non-
817 NULL result from PySequence_Fast(), more quickly than calling
818 PySequence_Size().
819
Barry Warsaw012852b2001-11-16 16:17:27 +0000820- New argument unpacking function PyArg_UnpackTuple() added.
821
822- New functions PyObject_CallFunctionObjArgs() and
823 PyObject_CallMethodObjArgs() have been added to make it more
824 convenient and efficient to call functions and methods from C.
825
826- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
827 possible that this will propagate errors it didn't before.
828
829- New function PyObject_CheckReadBuffer(), which returns true if its
830 argument supports the single-segment readable buffer interface.
831
Tim Peters84362bc2001-10-19 17:55:30 +0000832New platforms
833
Guido van Rossum86443212001-10-27 22:28:54 +0000834- We've finally confirmed that this release builds on HP-UX 11.00,
835 *with* threads, and passes the test suite.
836
Tim Peters7a33d8b2001-11-05 02:51:07 +0000837- Thanks to a series of patches from Michael Muller, Python may build
838 again under OS/2 Visual Age C++.
839
Guido van Rossum49192142001-10-24 20:51:44 +0000840- Updated RISCOS port by Dietmar Schwertberger.
841
Tim Peters84362bc2001-10-19 17:55:30 +0000842Tests
843
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000844- Added a test script for the curses module. It isn't run automatically;
845 regrtest.py must be run with '-u curses' to enable it.
846
Tim Peters84362bc2001-10-19 17:55:30 +0000847Windows
848
Barry Warsaw012852b2001-11-16 16:17:27 +0000849Mac
850
851- PythonScript has been moved to unsupported and is slated to be
852 removed completely in the next release.
853
854- It should now be possible to build applets that work on both OS9 and
855 OSX.
856
857- The core is now linked with CoreServices not Carbon; as a side
858 result, default 8bit encoding on OSX is now ASCII.
859
860- Python should now build on OSX 10.1.1
861
Tim Peters84362bc2001-10-19 17:55:30 +0000862
Tim Petersabf925f2001-09-28 21:53:42 +0000863What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000864Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000865===========================
866
867Type/class unification and new-style classes
868
Guido van Rossum687ae002001-10-15 22:03:32 +0000869- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000870 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000871 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000872 remains: the __dict__ of a new-style class is a read-only proxy; you
873 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000874 __defined__ attribute of new-style types no longer exists, for lack
875 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000876 future a __cache__ may be resurrected with a similar function, if I
877 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000878
Tim Peters1c9ca872001-10-04 06:43:12 +0000879- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
880 always returned None, even when there was a class docstring).
881
882- doctest now finds and runs docstrings attached to new-style classes,
883 class methods, static methods, and properties.
884
Guido van Rossum9074ef62001-10-16 21:34:49 +0000885Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000886
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000887- A very subtle syntactical pitfall in list comprehensions was fixed.
888 For example: [a+b for a in 'abc', for b in 'def']. The comma in
889 this example is a mistake. Previously, this would silently let 'a'
890 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
891 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
892 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
893 Note that [a for a in <singleton>] is a convoluted way to say
894 [<singleton>] anyway, so it's not like any expressiveness is lost.
895
Guido van Rossum9074ef62001-10-16 21:34:49 +0000896- getattr(obj, name, default) now only catches AttributeError, as
897 documented, rather than returning the default value for all
898 exceptions (which could mask bugs in a __getattr__ hook, for
899 example).
900
Fred Drakecb7a6b52001-10-22 18:41:51 +0000901- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000902 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000903 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000904 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000905
Guido van Rossum1c486092001-10-19 02:05:35 +0000906- unicode(obj) now behaves more like str(obj), accepting arbitrary
907 objects, and calling a __unicode__ method if it exists.
908 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000909 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000910
Barry Warsawf6fb1712001-10-19 05:35:40 +0000911- isinstance() now allows any object as the first argument and a
912 class, a type or something with a __bases__ tuple attribute for the
913 second argument. The second argument may also be a tuple of a
914 class, type, or something with __bases__, in which case isinstance()
915 will return true if the first argument is an instance of any of the
916 things contained in the second argument tuple. E.g.
917
918 isinstance(x, (A, B))
919
920 returns true if x is an instance of A or B.
921
Guido van Rossum9074ef62001-10-16 21:34:49 +0000922Extension modules
923
924- thread.start_new_thread() now returns the thread ID (previously None).
925
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000926- binascii has now two quopri support functions, a2b_qp and b2a_qp.
927
Guido van Rossumc524d952001-10-19 01:31:59 +0000928- readline now supports setting the startup_hook and the
929 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000930
Guido van Rossumc524d952001-10-19 01:31:59 +0000931- os and posix supports chroot(), setgroups() and unsetenv() where
932 available. The stat(), fstat(), statvfs() and fstatvfs() functions
933 now return "pseudo-sequences" -- the various fields can now be
934 accessed as attributes (e.g. os.stat("/").st_mtime) but for
935 backwards compatibility they also behave as a fixed-length sequence.
936 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000937 attributes.
938
939- time: localtime(), gmtime() and strptime() now return a
940 pseudo-sequence similar to the os.stat() return value, with
941 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000942
Guido van Rossum9074ef62001-10-16 21:34:49 +0000943- Decompression objects in the zlib module now accept an optional
944 second parameter to decompress() that specifies the maximum amount
945 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000946
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000947- optional SSL support in the socket module now exports OpenSSL
948 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
949 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000950 automatically seed its PRNG. Also, the keyfile and certfile
951 arguments to socket.ssl() are now optional.
952
953- posixmodule (and by extension, the os module on POSIX platforms) now
954 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000955
Guido van Rossum9074ef62001-10-16 21:34:49 +0000956Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000957
Tim Peters7402f792001-10-02 03:53:41 +0000958- doctest now excludes functions and classes not defined by the module
959 being tested, thanks to Tim Hochberg.
960
Fred Drakecb7a6b52001-10-22 18:41:51 +0000961- HotShot, a new profiler implemented using a C-based callback, has
962 been added. This substantially reduces the overhead of profiling,
963 but it is still quite preliminary. Support modules and
964 documentation will be added in upcoming releases (before 2.2 final).
965
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000966- profile now produces correct output in situations where an exception
967 raised in Python is cleared by C code (e.g. hasattr()). This used
968 to cause wrong output, including spurious claims of recursive
969 functions and attribution of time spent to the wrong function.
970
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000971 The code and documentation for the derived OldProfile and HotProfile
972 profiling classes was removed. The code hasn't worked for years (if
973 you tried to use them, they raised exceptions). OldProfile
974 intended to reproduce the behavior of the profiler Python used more
975 than 7 years ago, and isn't interesting anymore. HotProfile intended
976 to provide a faster profiler (but producing less information), and
977 that's a worthy goal we intend to meet via a different approach (but
978 without losing information).
979
Tim Peterscce092d2001-10-09 05:31:56 +0000980- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000981 a much better system-specific calibration constant. The constant can
982 now be specified in an instance constructor, or as a Profile class or
983 instance variable, instead of by editing profile.py's source code.
984 Calibration must still be done manually (see the docs for the profile
985 module).
986
987 Note that Profile.calibrate() must be overriden by subclasses.
988 Improving the accuracy required exploiting detailed knowledge of
989 profiler internals; the earlier method abstracted away the details
990 and measured a simplified model instead, but consequently computed
991 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000992
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000993- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000994 which indicates whether output is intended for the header 'Q'
995 encoding.
996
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000997- The SocketServer.ThreadingMixIn class now closes the request after
998 finish_request() returns. (Not when it errors out though.)
999
Barry Warsawf6fb1712001-10-19 05:35:40 +00001000- The nntplib module's NNTP.body() method has grown a `file' argument
1001 to allow saving the message body to a file.
1002
1003- The email package has added a class email.Parser.HeaderParser which
1004 only parses headers and does not recurse into the message's body.
1005 Also, the module/class MIMEAudio has been added for representing
1006 audio data (contributed by Anthony Baxter).
1007
1008- ftplib should be able to handle files > 2GB.
1009
1010- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1011 ON, and OFF.
1012
Fred Drakecb7a6b52001-10-22 18:41:51 +00001013- xml.dom.minidom NodeList objects now support the length attribute
1014 and item() method as required by the DOM specifications.
1015
Guido van Rossumed554f62001-10-02 23:15:37 +00001016Tools/Demos
1017
1018- Demo/dns was removed. It no longer serves any purpose; a package
1019 derived from it is now maintained by Anthony Baxter, see
1020 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001021
Barry Warsawf6fb1712001-10-19 05:35:40 +00001022- The freeze tool has been made more robust, and two new options have
1023 been added: -X and -E.
1024
Tim Petersabf925f2001-09-28 21:53:42 +00001025Build
1026
Barry Warsawf6fb1712001-10-19 05:35:40 +00001027- configure will use CXX in LINKCC if CXX is used to build main() and
1028 the system requires to link a C++ main using the C++ compiler.
1029
Tim Petersabf925f2001-09-28 21:53:42 +00001030C API
1031
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001032- The documentation for the tp_compare slot is updated to require that
1033 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1034 not correct. This is not yet enforced but will be enforced in
1035 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1036 "NotImplemented". Right now, -1 should be used for an error return.
1037
Tim Petersd38b1c72001-09-30 05:09:37 +00001038- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1039 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1040 as long) arguments.
1041
Guido van Rossum3c288632001-10-16 21:13:49 +00001042- PyThread_start_new_thread() now returns a long int giving the thread
1043 ID, if one can be calculated; it returns -1 for error, 0 if no
1044 thread ID is calculated (this is an incompatible change, but only
1045 the thread module used this API). This code has only really been
1046 tested on Linux and Windows; other platforms please beware (and
1047 report any bugs or strange behavior).
1048
Guido van Rossum1c486092001-10-19 02:05:35 +00001049- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1050 input.
1051
Tim Petersabf925f2001-09-28 21:53:42 +00001052New platforms
1053
1054Tests
1055
1056Windows
1057
Tim Peters04cf1d32001-10-09 22:39:40 +00001058- Installer: If you install IDLE, and don't disable file-extension
1059 registration, a new "Edit with IDLE" context (right-click) menu entry
1060 is created for .py and .pyw files.
1061
Tim Peters1ce3cf72001-10-01 17:58:40 +00001062- The signal module now supports SIGBREAK on Windows, thanks to Steven
1063 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1064 action remains to call Win32 ExitProcess(). This can be changed via
1065 signal.signal(). For example:
1066
1067 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1068 # (SIGINT) behavior.
1069 import signal
1070 signal.signal(signal.SIGBREAK,
1071 signal.default_int_handler)
1072
1073 try:
1074 while 1:
1075 pass
1076 except KeyboardInterrupt:
1077 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1078 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1079 # program without the possibility for any Python-level cleanup).
1080 print "Clean exit"
1081
Tim Petersabf925f2001-09-28 21:53:42 +00001082
Tim Petersb07352e2001-09-08 01:25:47 +00001083What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001084Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001085===========================
1086
Guido van Rossum808eea72001-09-25 04:15:41 +00001087Type/class unification and new-style classes
1088
1089- pydoc and inspect are now aware of new-style classes;
1090 e.g. help(list) at the interactive prompt now shows proper
1091 documentation for all operations on list objects.
1092
1093- Applications using Jim Fulton's ExtensionClass module can now safely
1094 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1095 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1096 examples also work again. It is hoped that Gtk and Boost also work
1097 with 2.2a4 and beyond. (If you can confirm this, please write
1098 webmaster@python.org; if there are still problems, please open a bug
1099 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001100
Tim Peters66c1a522001-09-24 21:17:50 +00001101- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001102 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001103 in the constructed property object. fget, fset and fdel weren't
1104 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1105 associate a docstring with a property.
1106
Guido van Rossum808eea72001-09-25 04:15:41 +00001107- Comparison overloading is now more completely implemented. For
1108 example, a str subclass instance can properly be compared to a str
1109 instance, and it can properly overload comparison. Ditto for most
1110 other built-in object types.
1111
1112- The repr() of new-style classes has changed; instead of <type
1113 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1114 *except* for built-in types, which are still rendered as <type
1115 'Foo'> (to avoid upsetting existing code that might parse or
1116 otherwise rely on repr() of certain type objects).
1117
1118- The repr() of new-style objects is now always <Foo object at XXX>;
1119 previously, it was sometimes <Foo instance at XXX>.
1120
1121- For new-style classes, what was previously called __getattr__ is now
1122 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001123 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001124 one in classic classes is defined which is called only if regular
1125 attribute access raises AttributeError; to catch *all* attribute
1126 access, you can use __getattribute__ (for new-style classes). If
1127 both are defined, __getattribute__ is called first, and if it raises
1128 AttributeError, __getattr__ is called.
1129
1130- The __class__ attribute of new-style objects can be assigned to.
1131 The new class must have the same C-level object layout as the old
1132 class.
1133
1134- The builtin file type can be subclassed now. In the usual pattern,
1135 "file" is the name of the builtin type, and file() is a new builtin
1136 constructor, with the same signature as the builtin open() function.
1137 file() is now the preferred way to open a file.
1138
1139- Previously, __new__ would only see sequential arguments passed to
1140 the type in a constructor call; __init__ would see both sequential
1141 and keyword arguments. This made no sense whatsoever any more, so
1142 now both __new__ and __init__ see all arguments.
1143
1144- Previously, hash() applied to an instance of a subclass of str or
1145 unicode always returned 0. This has been repaired.
1146
1147- Previously, an operation on an instance of a subclass of an
1148 immutable type (int, long, float, complex, tuple, str, unicode),
1149 where the subtype didn't override the operation (and so the
1150 operation was handled by the builtin type), could return that
1151 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001152 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001153 with the same value as s.
1154
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001155- Provisional support for pickling new-style objects has been added.
1156
Guido van Rossum808eea72001-09-25 04:15:41 +00001157Core
1158
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001159- file.writelines() now accepts any iterable object producing strings.
1160
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001161- PyUnicode_FromEncodedObject() now works very much like
1162 PyObject_Str(obj) in that it tries to use __str__/tp_str
1163 on the object if the object is not a string or buffer. This
1164 makes unicode() behave like str() when applied to non-string/buffer
1165 objects.
1166
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001167- PyFile_WriteObject now passes Unicode objects to the file's write
1168 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001169 of a print statement must support Unicode objects, i.e. they must
1170 at least convert them into ASCII strings.
1171
Guido van Rossum624c8af2001-09-18 15:21:04 +00001172- Thread scheduling on Solaris should be improved; it is no longer
1173 necessary to insert a small sleep at the start of a thread in order
1174 to let other runnable threads be scheduled.
1175
Tim Petersb07352e2001-09-08 01:25:47 +00001176Library
1177
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001178- StringIO.StringIO instances and cStringIO.StringIO instances support
1179 read character buffer compatible objects for their .write() methods.
1180 These objects are converted to strings and then handled as such
1181 by the instances.
1182
Barry Warsaw2f600732001-09-24 04:28:10 +00001183- The "email" package has been added. This is basically a port of the
1184 mimelib package <http://sf.net/projects/mimelib> with API changes
1185 and some implementations updated to use iterators and generators.
1186
Tim Peters8a9c2842001-09-22 21:30:22 +00001187- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1188 restores the ability of Tools/scripts/ndiff.py to start producing output
1189 before the entire comparison is complete.
1190
Barry Warsaw58b072d2001-09-22 04:44:21 +00001191- StringIO.StringIO instances and cStringIO.StringIO instances support
1192 iteration just like file objects (i.e. their .readline() method is
1193 called for each iteration until it returns an empty string).
1194
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001195- The codecs module has grown four new helper APIs to access
1196 builtin codecs: getencoder(), getdecoder(), getreader(),
1197 getwriter().
1198
Guido van Rossum624c8af2001-09-18 15:21:04 +00001199- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1200 simplifies writing XML RPC servers.
1201
Barry Warsaw647d5e82001-09-28 17:01:02 +00001202- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001203 after interpretation of symbolic links. On non-Unix systems, this
1204 is an alias for os.path.abspath().
1205
Tim Peters16a77ad2001-09-08 04:00:12 +00001206- operator.indexOf() (PySequence_Index() in the C API) now works with any
1207 iterable object.
1208
Guido van Rossum624c8af2001-09-18 15:21:04 +00001209- smtplib now supports various authentication and security features of
1210 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001211
Guido van Rossum624c8af2001-09-18 15:21:04 +00001212- hmac: a new module implementing keyed hashing for message
1213 authentication.
1214
1215- mimetypes now recognizes more extensions and file types. At the
1216 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001217
Guido van Rossum624c8af2001-09-18 15:21:04 +00001218- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001219 Python 2.2 bytecode generation. It has also been promoted from a
1220 Tool to a standard library package. (Tools/compiler still exists as
1221 a sample driver.)
1222
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001223Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001224
Tim Petersb07352e2001-09-08 01:25:47 +00001225Build
1226
Guido van Rossum624c8af2001-09-18 15:21:04 +00001227- Large file support (LFS) is now automatic when the platform supports
1228 it; no more manual configuration tweaks are needed. On Linux, at
1229 least, it's possible to have a system whose C library supports large
1230 files but whose kernel doesn't; in this case, large file support is
1231 still enabled but doesn't do you any good unless you upgrade your
1232 kernel or share your Python executable with another system whose
1233 kernel has large file support.
1234
1235- The configure script now supplies plausible defaults in a
1236 cross-compilation environment. This doesn't mean that the supplied
1237 values are always correct, or that cross-compilation now works
1238 flawlessly -- but it's a first step (and it shuts up most of
1239 autoconf's warnings about AC_TRY_RUN).
1240
1241- The Unix build is now a bit less chatty, courtesy of the parser
1242 generator. The build is completely silent (except for errors) when
1243 using "make -s", thanks to a -q option to setup.py.
1244
Tim Petersb07352e2001-09-08 01:25:47 +00001245C API
1246
Guido van Rossum624c8af2001-09-18 15:21:04 +00001247- The "structmember" API now supports some new flag bits to deny read
1248 and/or write access to attributes in restricted execution mode.
1249
Tim Petersb07352e2001-09-08 01:25:47 +00001250New platforms
1251
Guido van Rossum624c8af2001-09-18 15:21:04 +00001252- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1253 (http://familiar.handhelds.org).
1254
Tim Petersb07352e2001-09-08 01:25:47 +00001255Tests
1256
Tim Peters8a9c2842001-09-22 21:30:22 +00001257- The "classic" standard tests, which work by comparing stdout to
1258 an expected-output file under Lib/test/output/, no longer stop at
1259 the first mismatch. Instead the test is run to completion, and a
1260 variant of ndiff-style comparison is used to report all differences.
1261 This is much easier to understand than the previous style of reporting.
1262
1263- The unittest-based standard tests now use regrtest's test_main()
1264 convention, instead of running as a side-effect of merely being
1265 imported. This allows these tests to be run in more natural and
1266 flexible ways as unittests, outside the regrtest framework.
1267
1268- regrtest.py is much better integrated with unittest and doctest now,
1269 especially in regard to reporting errors.
1270
Tim Petersb07352e2001-09-08 01:25:47 +00001271Windows
1272
Guido van Rossum624c8af2001-09-18 15:21:04 +00001273- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001274 that support it (NTFS under Windows 2000). See "What's New in
1275 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001276
Tim Petersb07352e2001-09-08 01:25:47 +00001277
Tim Petersedc99312001-08-22 21:36:50 +00001278What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001279Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001280===========================
1281
1282Core
1283
Tim Peters9fffa3e2001-09-04 05:14:19 +00001284- Conversion of long to float now raises OverflowError if the long is too
1285 big to represent as a C double.
1286
Tim Peters32f453e2001-09-03 08:35:41 +00001287- The 3-argument builtin pow() no longer allows a third non-None argument
1288 if either of the first two arguments is a float, or if both are of
1289 integer types and the second argument is negative (in which latter case
1290 the arguments are converted to float, so this is really the same
1291 restriction).
1292
Tim Peters5d2b77c2001-09-03 05:47:38 +00001293- The builtin dir() now returns more information, and sometimes much
1294 more, generally naming all attributes of an object, and all attributes
1295 reachable from the object via its class, and from its class's base
1296 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1297 an empty list. In 2.2a3,
1298
1299 >>> dir([])
1300 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1301 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1302 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1303 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1304 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1305 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1306 'reverse', 'sort']
1307
1308 dir(module) continues to return only the module's attributes, though.
1309
Tim Petersbdee63f2001-09-02 03:40:59 +00001310- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001311 than raising OverflowError. This is a partial implementation of PEP
1312 237. You can use -Wdefault::OverflowWarning to enable a warning for
1313 this situation, and -Werror::OverflowWarning to revert to the old
1314 OverflowError exception.
1315
Guido van Rossum61c345f2001-09-04 03:26:15 +00001316- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001317 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001318 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1319 -Qold, meaning the / operator has its classic meaning and no
1320 warnings are issued. Using -Qwarn issues a run-time warning about
1321 all uses of classic division for int and long arguments; -Qwarnall
1322 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001323 (for use with fixdiv.py).
1324 [Note: the remainder of this paragraph (preserved below) became
1325 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1326 <obsolete>
1327 Using -Qnew is questionable; it turns on new division by default, but
1328 only in the __main__ module. You can usefully combine -Qwarn or
1329 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1330 warns about classic division everywhere else.
1331 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001332
Tim Petersbdee63f2001-09-02 03:40:59 +00001333- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001334 long, float, str, unicode, and tuple. (The types complex, list and
1335 dictionary can also be subclassed; this was introduced earlier.)
1336 Note that restrictions apply when subclassing immutable built-in
1337 types: you can only affect the value of the instance by overloading
1338 __new__. You can add mutable attributes, and the subclass instances
1339 will have a __dict__ attribute, but you cannot change the "value"
1340 (as implemented by the base class) of an immutable subclass instance
1341 once it is created.
1342
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001343- The dictionary constructor now takes an optional argument, a
1344 mapping-like object, and initializes the dictionary from its
1345 (key, value) pairs.
1346
Tim Petersbdee63f2001-09-02 03:40:59 +00001347- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001348 "cooperative super calls" in a multiple inheritance setting. For an
1349 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1350
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001351- A new built-in type, property, has been added. This enables the
1352 creation of "properties". These are attributes implemented by
1353 getter and setter functions (or only one of these for read-only or
1354 write-only attributes), without the need to override __getattr__.
1355 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001356
Tim Petersbdee63f2001-09-02 03:40:59 +00001357- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001358 liberalized, to allow leading zeroes. Examples of literals now
1359 legal that were SyntaxErrors before:
1360
1361 00.0 0e3 0100j 07.5 00000000000000000008.
1362
Tim Petersbdee63f2001-09-02 03:40:59 +00001363- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001364 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1365
Tim Petersedc99312001-08-22 21:36:50 +00001366Library
1367
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001368- telnetlib includes symbolic names for the options, and support for
1369 setting an option negotiation callback.
1370
Tim Petersa40c7932001-09-05 22:36:56 +00001371- The new C standard no longer requires that math libraries set errno to
1372 ERANGE on overflow. For platform libraries that exploit this new
1373 freedom, Python's overflow-checking was wholly broken. A new overflow-
1374 checking scheme attempts to repair that, but may not be reliable on all
1375 platforms (C doesn't seem to provide anything both useful and portable
1376 in this area anymore).
1377
Martin v. Löwis44f86962001-09-05 13:44:54 +00001378- Asynchronous timeout actions are available through the new class
1379 threading.Timer.
1380
Tim Peters78526162001-09-05 00:53:45 +00001381- math.log and math.log10 now return sensible results for even huge
1382 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1383
Tim Petersbdee63f2001-09-02 03:40:59 +00001384- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001385 currently held. See the docs for the imp module.
1386
Tim Petersbdee63f2001-09-02 03:40:59 +00001387- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001388 dumps containing ints written on platforms where Python ints are 8 bytes.
1389 When read on a box where Python ints are 4 bytes, such values are
1390 converted to Python longs.
1391
Tim Petersbdee63f2001-09-02 03:40:59 +00001392- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001393 code objects is no longer allowed. This plugs a security hole.
1394
Steve Purcell6091cd62001-09-06 16:05:17 +00001395- unittest.TestResult instances no longer store references to tracebacks
1396 generated by test failures. This prevents unexpected dangling references
1397 to objects that should be garbage collected between tests.
1398
Tim Petersedc99312001-08-22 21:36:50 +00001399Tools
1400
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001401- Tools/scripts/fixdiv.py has been added which can be used to fix
1402 division operators as per PEP 238.
1403
Tim Petersedc99312001-08-22 21:36:50 +00001404Build
1405
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001406- If you are an adventurous person using Mac OS X you may want to look at
1407 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1408 application, which can be used for experimenting with Carbon or Cocoa.
1409 Discussion of this on pythonmac-sig, please.
1410
Tim Peters7eea37e2001-09-04 22:08:56 +00001411C API
1412
1413- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001414
Tim Peters9fffa3e2001-09-04 05:14:19 +00001415- Note that PyLong_AsDouble can fail! This has always been true, but no
1416 callers checked for it. It's more likely to fail now, because overflow
1417 errors are properly detected now. The proper way to check:
1418
1419 double x = PyLong_AsDouble(some_long_object);
1420 if (x == -1.0 && PyErr_Occurred()) {
1421 /* The conversion failed. */
1422 }
1423
Tim Petersbdee63f2001-09-02 03:40:59 +00001424- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001425 compile but will not participate in GC. To upgrade an extension
1426 module:
1427
1428 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001429
Neil Schemenauer4042c692001-08-30 15:38:01 +00001430 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1431 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001432
Neil Schemenauer4042c692001-08-30 15:38:01 +00001433 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1434 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001435
Neil Schemenauer4042c692001-08-30 15:38:01 +00001436 - remove PyGC_HEAD_SIZE from object size calculations
1437
1438 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1439
Tim Petersbdee63f2001-09-02 03:40:59 +00001440- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001441 These can be used safely to construct string objects from a
1442 sprintf-style format string (similar to the format string supported
1443 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001444
Tim Petersedc99312001-08-22 21:36:50 +00001445New platforms
1446
Tim Petersb7da0902001-09-02 23:01:43 +00001447- Stephen Hansen contributed patches sufficient to get a clean compile
1448 under Borland C (Windows), but he reports problems running it and ran
1449 out of time to complete the port. Volunteers? Expect a MemoryError
1450 when importing the types module; this is probably shallow, and
1451 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001452
Tim Petersedc99312001-08-22 21:36:50 +00001453Tests
1454
1455Windows
1456
Tim Peters6e13a562001-09-06 00:32:15 +00001457- Large file support is now enabled on Win32 platforms as well as on
1458 Win64. This means that, for example, you can use f.tell() and f.seek()
1459 to manipulate files larger than 2 gigabytes (provided you have enough
1460 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001461 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1462 filesize limit, and large file support makes no difference there.
1463 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1464 NTFS has no practical limit on file size, and files of any size can be
1465 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001466
Tim Petersbdee63f2001-09-02 03:40:59 +00001467- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001468 points to command.com (patch from Brian Quinlan).
1469
Tim Petersedc99312001-08-22 21:36:50 +00001470
Tim Peters20f51a72001-07-21 02:31:40 +00001471What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001472Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001473===========================
1474
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001475Build
1476
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001477- Tim Peters developed a brand new Windows installer using Wise 8.1,
1478 generously donated to us by Wise Solutions.
1479
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001480- configure supports a new option --enable-unicode, with the values
1481 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1482 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001483
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001484- A new configure option --enable-framework builds a Mac OS X framework,
1485 which "make frameworkinstall" will install. This provides a starting
1486 point for more mac-like functionality, join pythonmac-sig@python.org
1487 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001488
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001489- The NeXT platform is no longer supported.
1490
1491- The `new' module is now statically linked.
1492
Tim Peters0afb6092001-08-15 06:06:44 +00001493Tools
1494
1495- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001496 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001497 the module docstring for details.
1498
Tim Peters20f51a72001-07-21 02:31:40 +00001499Tests
1500
Tim Peters5e824c32001-08-12 22:25:01 +00001501- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001502 platforms, allowing to give clearer test result output. regrtest
1503 also has optional --use/-u switch to run normally disabled tests
1504 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001505
Tim Peters20f51a72001-07-21 02:31:40 +00001506- Several new tests in the standard test suite, with special thanks to
1507 Nick Mathewson.
1508
1509Core
1510
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001511- The floor division operator // has been added as outlined in PEP
1512 238. The / operator still provides classic division (and will until
1513 Python 3.0) unless "from __future__ import division" is included, in
1514 which case the / operator will provide true division. The operator
1515 module provides truediv() and floordiv() functions. Augmented
1516 assignment variants are included, as are the equivalent overloadable
1517 methods and C API methods. See the PEP for a full discussion:
1518 <http://python.sf.net/peps/pep-0238.html>
1519
Tim Peters6cd6a822001-08-17 22:11:27 +00001520- Future statements are now effective in simulated interactive shells
1521 (like IDLE). This should "just work" by magic, but read Michael
1522 Hudson's "Future statements in simulated shells" PEP 264 for full
1523 details: <http://python.sf.net/peps/pep-0264.html>.
1524
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001525- The type/class unification (PEP 252-253) was integrated into the
1526 trunk and is not so tentative any more (the exact specification of
1527 some features is still tentative). A lot of work has done on fixing
1528 bugs and adding robustness and features (performance still has to
1529 come a long way).
1530
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001531- Warnings about a mismatch in the Python API during extension import
1532 now use the Python warning framework (which makes it possible to
1533 write filters for these warnings).
1534
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001535- A function's __dict__ (aka func_dict) will now always be a
1536 dictionary. It used to be possible to delete it or set it to None,
1537 but now both actions raise TypeErrors. It is still legal to set it
1538 to a dictionary object. Getting func.__dict__ before any attributes
1539 have been assigned now returns an empty dictionary instead of None.
1540
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001541- A new command line option, -E, was added which disables the use of
1542 all environment variables, or at least those that are specifically
1543 significant to Python. Usually those have a name starting with
1544 "PYTHON". This was used to fix a problem where the tests fail if
1545 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1546 older distribution.
1547
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001548Library
1549
Tim Peters5e824c32001-08-12 22:25:01 +00001550- New class Differ and new functions ndiff() and restore() in difflib.py.
1551 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001552 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001553
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001554- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1555 value using the minimal quoting required for the value; more
1556 reliable than using xml.sax.saxutils.escape() for attribute values.
1557
1558- Readline completion support for cmd.Cmd was added.
1559
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001560- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1561
1562- Added function threading.BoundedSemaphore()
1563
1564- Added Ka-Ping Yee's cgitb.py module.
1565
1566- The `new' module now exposes the CO_xxx flags.
1567
Martin v. Löwis560da622001-11-24 09:24:51 +00001568- The gc module offers the get_referents function.
1569
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001570New platforms
1571
1572C API
1573
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001574- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1575 which provide a cross-platform implementations for the
1576 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1577 the standard sprintf() and vsprintf() C lib APIs, these versions
1578 apply bounds checking on the used buffer which enhances protection
1579 against buffer overruns.
1580
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001581- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001582 and extensions using different Unicode widths is rendered next to
1583 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001584 will result in an ImportError. Unicode extensions writers must make
1585 sure to check the Unicode width compatibility in their extensions by
1586 using at least one of the mangled Unicode APIs in the extension.
1587
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001588- Two new flags METH_NOARGS and METH_O are available in method definition
1589 tables to simplify implementation of methods with no arguments and a
1590 single untyped argument. Calling such methods is more efficient than
1591 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1592 deprecated.
1593
Tim Petersc1731372001-08-04 08:12:36 +00001594Windows
1595
1596- "import module" now compiles module.pyw if it exists and nothing else
1597 relevant is found.
1598
Tim Peters20f51a72001-07-21 02:31:40 +00001599
Guido van Rossum55a78992001-07-17 17:22:32 +00001600What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001601Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001602===========================
1603
1604Core
Tim Petersa814db52001-05-14 07:05:58 +00001605
Tim Peters6d6c1a32001-08-02 04:15:00 +00001606- TENTATIVELY, a large amount of code implementing much of what's
1607 described in PEP 252 (Making Types Look More Like Classes) and PEP
1608 253 (Subtyping Built-in Types) was added. This will be released
1609 with Python 2.2a1. Documentation will be provided separately
1610 through http://www.python.org/2.2/. The purpose of releasing this
1611 with Python 2.2a1 is to test backwards compatibility. It is
1612 possible, though not likely, that a decision is made not to release
1613 this code as part of 2.2 final, if any serious backwards
1614 incompapatibilities are found during alpha testing that cannot be
1615 repaired.
1616
Guido van Rossum55a78992001-07-17 17:22:32 +00001617- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001618 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001619 more 'yield' statements. See PEP 255. Since this adds a new
1620 keyword to the language, this feature must be enabled by including a
1621 future statement: "from __future__ import generators" (see PEP 236).
1622 Generators will become a standard feature in a future release
1623 (probably 2.3). Without this future statement, 'yield' remains an
1624 ordinary identifier, but a warning is issued each time it is used.
1625 (These warnings currently don't conform to the warnings framework of
1626 PEP 230; we intend to fix this in 2.2a2.)
1627
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001628- The UTF-16 codec was modified to be more RFC compliant. It will now
1629 only remove BOM characters at the start of the string and then
1630 only if running in native mode (UTF-16-LE and -BE won't remove a
1631 leading BMO character).
1632
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001633- Strings now have a new method .decode() to complement the already
1634 existing .encode() method. These two methods provide direct access
1635 to the corresponding decoders and encoders of the registered codecs.
1636
1637 To enhance the usability of the .encode() method, the special
1638 casing of Unicode object return values was dropped (Unicode objects
1639 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001640
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001641 Both methods will now return whatever the codec in charge of the
1642 requested encoding returns as object, e.g. Unicode codecs will
1643 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1644 will return u"äöü"). This enables codec writer to create codecs
1645 for various simple to use conversions.
1646
1647 New codecs were added to demonstrate these new features (the .encode()
1648 and .decode() columns indicate the type of the returned objects):
1649
1650 Name | .encode() | .decode() | Description
1651 ----------------------------------------------------------------------
1652 uu | string | string | UU codec (e.g. for email)
1653 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001654 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001655 zlib | string | string | zlib compression
1656 hex | string | string | 2-byte hex codec
1657 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1658
Mark Hammond2a0af792001-05-14 03:09:36 +00001659- Some operating systems now support the concept of a default Unicode
1660 encoding for file system operations. Notably, Windows supports 'mbcs'
1661 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001662 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001663 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001664
1665 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001666 functions that return filenames (such as os.listdir()) to return Python
1667 string objects pre-encoded using the default file system encoding for
1668 the platform. As this encoding is likely to be different from Python's
1669 default encoding, converting this name to a Unicode object before passing
1670 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001671 would attempt to use its default encoding (generally ASCII) rather than
1672 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001673
Tim Petersa814db52001-05-14 07:05:58 +00001674 In general, this change simply removes surprises when working with
1675 Unicode and the file system, making these operations work as you expect,
1676 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001677 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001678
Tim Peters61dff2b2001-05-08 15:43:37 +00001679- Float (and complex) literals in source code were evaluated to full
1680 precision only when running from a .py file; the same code loaded from a
1681 .pyc (or .pyo) file could suffer numeric differences starting at about the
1682 12th significant decimal digit. For example, on a machine with IEEE-754
1683 floating arithmetic,
1684
1685 x = 9007199254740992.0
1686 print long(x)
1687
1688 printed 9007199254740992 if run directly from .py, but 9007199254740000
1689 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1690 str(float) instead of repr(float) when building code objects. marshal
1691 now uses repr(float) instead, which should reproduce floats to full
1692 machine precision (assuming the platform C float<->string I/O conversion
1693 functions are of good quality).
1694
1695 This may cause floating-point results to change in some cases, and
1696 usually for the better, but may also cause numerically unstable
1697 algorithms to break.
1698
Tim Peters2f228e72001-05-13 00:19:31 +00001699- The implementation of dicts suffers fewer collisions, which has speed
1700 benefits. However, the order in which dict entries appear in dict.keys(),
1701 dict.values() and dict.items() may differ from previous releases for a
1702 given dict. Nothing is defined about this order, so no program should
1703 rely on it. Nevertheless, it's easy to write test cases that rely on the
1704 order by accident, typically because of printing the str() or repr() of a
1705 dict to an "expected results" file. See Lib/test/test_support.py's new
1706 sortdict(dict) function for a simple way to display a dict in sorted
1707 order.
1708
Tim Peters7a3bfc32001-06-12 01:22:22 +00001709- Many other small changes to dicts were made, resulting in faster
1710 operation along the most common code paths.
1711
Guido van Rossum10315822001-05-01 20:54:30 +00001712- Dictionary objects now support the "in" operator: "x in dict" means
1713 the same as dict.has_key(x).
1714
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001715- The update() method of dictionaries now accepts generic mapping
1716 objects. Specifically the argument object must support the .keys()
1717 and __getitem__() methods. This allows you to say, for example,
1718 {}.update(UserDict())
1719
Guido van Rossum10315822001-05-01 20:54:30 +00001720- Iterators were added; this is a generalized way of providing values
1721 to a for loop. See PEP 234. There's a new built-in function iter()
1722 to return an iterator. There's a new protocol to get the next value
1723 from an iterator using the next() method (in Python) or the
1724 tp_iternext slot (in C). There's a new protocol to get iterators
1725 using the __iter__() method (in Python) or the tp_iter slot (in C).
1726 Iterating (i.e. a for loop) over a dictionary generates its keys.
1727 Iterating over a file generates its lines.
1728
Tim Petersf553f892001-05-01 20:45:31 +00001729- The following functions were generalized to work nicely with iterator
1730 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001731 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001732 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1733 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001734 join() method of strings
1735 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001736 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1737 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001738 right-hand side of assignment statements with multiple targets, such as
1739 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001740
Tim Petersd85e1022001-05-11 21:51:48 +00001741- Accessing module attributes is significantly faster (for example,
1742 random.random or os.path or yourPythonModule.yourAttribute).
1743
Tim Peterse63415e2001-05-08 04:38:29 +00001744- Comparing dictionary objects via == and != is faster, and now works even
1745 if the keys and values don't support comparisons other than ==.
1746
Tim Peters95bf9392001-05-10 08:32:44 +00001747- Comparing dictionaries in ways other than == and != is slower: there were
1748 insecurities in the dict comparison implementation that could cause Python
1749 to crash if the element comparison routines for the dict keys and/or
1750 values mutated the dicts. Making the code bulletproof slowed it down.
1751
Tim Peterseb28ef22001-06-02 05:27:19 +00001752- Collisions in dicts are resolved via a new approach, which can help
1753 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001754 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001755 faster now. Thanks to Christian Tismer for pointing out the cause and
1756 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001757
Tim Peters52e155e2001-06-16 05:42:57 +00001758- repr() is much faster for large containers (dict, list, tuple).
1759
1760
Tim Petersa814db52001-05-14 07:05:58 +00001761Library
1762
Fred Drake960fdf92001-07-20 18:38:26 +00001763- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1764 were added to the string module. These a locale-indenpendent
1765 constants, unlike letters, lowercase, and uppercase. These are now
1766 use in appropriate locations in the standard library.
1767
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001768- The flags used in dlopen calls can now be configured using
1769 sys.setdlopenflags and queried using sys.getdlopenflags.
1770
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001771- Fredrik Lundh's xmlrpclib is now a standard library module. This
1772 provides full client-side XML-RPC support. In addition,
1773 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1774 one asyncore-based). Thanks to Eric Raymond for the documentation.
1775
Guido van Rossum643d3912001-07-05 14:46:25 +00001776- The xrange() object is simplified: it no longer supports slicing,
1777 repetition, comparisons, efficient 'in' checking, the tolist()
1778 method, or the start, stop and step attributes. See PEP 260.
1779
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001780- A new function fnmatch.filter to filter lists of file names was added.
1781
Barry Warsawffd674d2001-05-22 16:00:10 +00001782- calendar.py uses month and day names based on the current locale.
1783
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001784- strop is now *really* obsolete (this was announced before with 1.6),
1785 and issues DeprecationWarning when used (except for the four items
1786 that are still imported into string.py).
1787
Tim Petersa814db52001-05-14 07:05:58 +00001788- Cookie.py now sorts key+value pairs by key in output strings.
1789
1790- pprint.isrecursive(object) didn't correctly identify recursive objects.
1791 Now it does.
1792
Tim Peters95b3f782001-05-14 18:39:41 +00001793- pprint functions now much faster for large containers (tuple, list, dict).
1794
Tim Peters7b9542a2001-06-10 23:40:19 +00001795- New 'q' and 'Q' format codes in the struct module, corresponding to C
1796 types "long long" and "unsigned long long" (on Windows, __int64). In
1797 native mode, these can be used only when the platform C compiler supports
1798 these types (when HAVE_LONG_LONG is #define'd by the Python config
1799 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001800 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1801 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001802
Guido van Rossum83213cc2001-06-12 16:48:52 +00001803- The site module installs a new built-in function 'help' that invokes
1804 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1805 it displays a message reminding the user to use 'help()' or
1806 'help(object)'.
1807
Tim Petersa814db52001-05-14 07:05:58 +00001808Tests
1809
1810- New test_mutants.py runs dict comparisons where the key and value
1811 comparison operators mutute the dicts randomly during comparison. This
1812 rapidly causes Python to crash under earlier releases (not for the faint
1813 of heart: it can also cause Win9x to freeze or reboot!).
1814
1815- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001816 pprint.isreadable() return sensible results. Also verifies that simple
1817 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001818
Tim Peters4324aa32001-05-28 22:30:08 +00001819C API
1820
1821- Removed the unused last_is_sticky argument from the internal
1822 _PyTuple_Resize(). If this affects you, you were cheating.
1823
1824
Guido van Rossum55a78992001-07-17 17:22:32 +00001825======================================================================
1826
1827
Guido van Rossumffe13be2001-04-16 18:46:45 +00001828What's New in Python 2.1 (final)?
1829=================================
1830
1831We only changed a few things since the last release candidate, all in
1832Python library code:
1833
1834- A bug in the locale module was fixed that affected locales which
1835 define no grouping for numeric formatting.
1836
1837- A few bugs in the weakref module's implementations of weak
1838 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1839 and the test suite was updated to check for these bugs.
1840
1841- An old bug in the os.path.walk() function (introduced in Python
1842 2.0!) was fixed: a non-existent file would cause an exception
1843 instead of being ignored.
1844
1845- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1846 PyChecker.
1847
1848
Guido van Rossum5b08f132001-04-16 02:05:23 +00001849What's New in Python 2.1c2?
1850===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001851
Guido van Rossum5b08f132001-04-16 02:05:23 +00001852A flurry of small changes, and one showstopper fixed in the nick of
1853time made it necessary to release another release candidate. The list
1854here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001855
Guido van Rossum5b08f132001-04-16 02:05:23 +00001856Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001857
Guido van Rossum5b08f132001-04-16 02:05:23 +00001858- Tim discovered a nasty bug in the dictionary code, caused by
1859 PyDict_Next() calling dict_resize(), and the GC code's use of
1860 PyDict_Next() violating an assumption in dict_items(). This was
1861 fixed with considerable amounts of band-aid, but the net effect is a
1862 saner and more robust implementation.
1863
1864- Made a bunch of symbols static that were accidentally global.
1865
1866Build and Ports
1867
1868- The setup.py script didn't check for a new enough version of zlib
1869 (1.1.3 is needed). Now it does.
1870
1871- Changed "make clean" target to also remove shared libraries.
1872
1873- Added a more general warning about the SGI Irix optimizer to README.
1874
1875Library
1876
1877- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1878 omitted the slash between host and file.html.
1879
1880- The mailbox module's _Mailbox class contained a completely broken
1881 and undocumented seek() method. Ripped it out.
1882
1883- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1884 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1885
1886- Fixed a few last-minute bugs in unittest.
1887
1888Extensions
1889
1890- Reverted the patch to the OpenSSL code in socketmodule.c to support
1891 RAND_status() and the EGD, and the subsequent patch that tried to
1892 fix it for pre-0.9.5 versions; the problem with the patch is that on
1893 some systems it issues a warning whenever socket is imported, and
1894 that's unacceptable.
1895
1896Tests
1897
1898- Fixed the pickle tests to work with "import test.test_pickle".
1899
1900- Tweaked test_locale.py to actually run the test Windows.
1901
1902- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1903 not "wb" (which is not a valid mode at all).
1904
1905- Fix pstats browser crashes. Import readline if it exists to make
1906 the user interface nicer.
1907
1908- Add "import thread" to the top of test modules that import the
1909 threading module (test_asynchat and test_threadedtempfile). This
1910 prevents test failures caused by a broken threading module resulting
1911 from a previously caught failed import.
1912
1913- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1914 needed on some platforms (e.g. Solaris 8) when the tests are run
1915 twice in succession.
1916
1917- Skip rather than fail test_sunaudiodev if no audio device is found.
1918
1919
1920What's New in Python 2.1c1?
1921===========================
1922
1923This list was significantly updated when 2.1c2 was released; the 2.1c1
1924release didn't mention most changes that were actually part of 2.1c1:
1925
1926Legal
1927
1928- Copyright was assigned to the Python Software Foundation (PSF) and a
1929 PSF license (very similar to the CNRI license) was added.
1930
1931- The CNRI copyright notice was updated to include 2001.
1932
1933Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001934
Guido van Rossumc9932722001-04-12 02:31:27 +00001935- After a public outcry, assignment to __debug__ is no longer illegal;
1936 instead, a warning is issued. It will become illegal in 2.2.
1937
Guido van Rossum5b08f132001-04-16 02:05:23 +00001938- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1939 "%#x" now always prepends "0x", even if the value is zero.
1940
1941- Fixed some nits in the bytecode compiler.
1942
1943- Fixed core dumps when calling certain kinds of non-functions.
1944
1945- Fixed various core dumps caused by reference count bugs.
1946
1947Build and Ports
1948
1949- Use INSTALL_SCRIPT to install script files.
1950
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001951- New port: SCO Unixware 7, by Billy G. Allie.
1952
Guido van Rossum5b08f132001-04-16 02:05:23 +00001953- Updated RISCOS port.
1954
1955- Updated BeOS port and notes.
1956
1957- Various other porting problems resolved.
1958
1959Library
1960
1961- The TERMIOS and SOCKET modules are now truly obsolete and
1962 unnecessary. Their symbols are incorporated in the termios and
1963 socket modules.
1964
1965- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1966 better tests for pickling.
1967
1968- threading: make Condition.wait() robust against KeyboardInterrupt.
1969
1970- zipfile: add support to zipfile to support opening an archive
1971 represented by an open file rather than a file name. Fix bug where
1972 the archive was not properly closed. Fixed a bug in this bugfix
1973 where flush() was called for a read-only file.
1974
1975- imputil: added an uninstall() method to the ImportManager.
1976
1977- Canvas: fixed bugs in lower() and tkraise() methods.
1978
1979- SocketServer: API change (added overridable close_request() method)
1980 so that the TCP server can explicitly close the request.
1981
1982- pstats: Eric Raymond added a simple interactive statistics browser,
1983 invoked when the module is run as a script.
1984
1985- locale: fixed a problem in format().
1986
1987- webbrowser: made it work when the BROWSER environment variable has a
1988 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1989 KDE 2. Fixed some other nits.
1990
1991- unittest: changes to allow using a different exception than
1992 AssertionError, and added a few more function aliases. Some other
1993 small changes.
1994
1995- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1996
1997- asynchat: fixed a critical bug in asynchat that slipped through the
1998 2.1b2 release. Fixed another rare bug.
1999
2000- Fix some unqualified except: clauses (always a bad code example).
2001
2002XML
2003
2004- pyexpat: new API get_version_string().
2005
2006- Fixed some minidom bugs.
2007
2008Extensions
2009
2010- Fixed a core dump in _weakref. Removed the weakref.mapping()
2011 function (it adds nothing to the API).
2012
2013- Rationalized the use of header files in the readline module, to make
2014 it compile (albeit with some warnings) with the very recent readline
2015 4.2, without breaking for earlier versions.
2016
2017- Hopefully fixed a buffering problem in linuxaudiodev.
2018
2019- Attempted a fix to make the OpenSSL support in the socket module
2020 work again with pre-0.9.5 versions of OpenSSL.
2021
2022Tests
2023
2024- Added a test case for asynchat and asyncore.
2025
2026- Removed coupling between tests where one test failing could break
2027 another.
2028
2029Tools
2030
2031- Ping added an interactive help browser to pydoc, fixed some nits
2032 in the rest of the pydoc code, and added some features to his
2033 inspect module.
2034
2035- An updated python-mode.el version 4.1 which integrates Ken
2036 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2037 much nicer in XEmacs and Emacs. When stepping through your program
2038 with pdb, in either the shell window or the *Python* window, the
2039 source file and line will be tracked by an arrow. Very cool!
2040
2041- IDLE: syntax warnings in interactive mode are changed into errors.
2042
2043- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002044 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002045
2046- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002047
Barry Warsaw11e89c72001-04-11 20:37:57 +00002048
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002049What's New in Python 2.1 beta 2?
2050================================
2051
Guido van Rossum053ae352001-03-22 14:17:21 +00002052(Unlisted are many fixed bugs, more documentation, etc.)
2053
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002054Core language, builtins, and interpreter
2055
Guido van Rossum053ae352001-03-22 14:17:21 +00002056- The nested scopes work (enabled by "from __future__ import
2057 nested_scopes") is completed; in particular, the future now extends
2058 into code executed through exec, eval() and execfile(), and into the
2059 interactive interpreter.
2060
2061- When calling a base class method (e.g. BaseClass.__init__(self)),
2062 this is now allowed even if self is not strictly spoken a class
2063 instance (e.g. when using metaclasses or the Don Beaudry hook).
2064
2065- Slice objects are now comparable but not hashable; this prevents
2066 dict[:] from being accepted but meaningless.
2067
2068- Complex division is now calculated using less braindead algorithms.
2069 This doesn't change semantics except it's more likely to give useful
2070 results in extreme cases. Complex repr() now uses full precision
2071 like float repr().
2072
2073- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2074
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002075- It is illegal to assign to the name __debug__, which is set when the
2076 interpreter starts. It is effectively a compile-time constant.
2077
2078- A warning will be issued if a global statement for a variable
2079 follows a use or assignment of that variable.
2080
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002081Standard library
2082
Guido van Rossum053ae352001-03-22 14:17:21 +00002083- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2084 inspired by JUnit), is now part of the standard library. You now
2085 have a choice of two testing frameworks: unittest requires you to
2086 write testcases as separate code, doctest gathers them from
2087 docstrings. Both approaches have their advantages and
2088 disadvantages.
2089
2090- A new module Tix was added, which wraps the Tix extension library
2091 for Tk. With that module, it is not necessary to statically link
2092 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2093 require" command. See Demo/tix/.
2094
2095- tzparse.py is now obsolete.
2096
2097- In gzip.py, the seek() and tell() methods are removed -- they were
2098 non-functional anyway, and it's better if callers can test for their
2099 existence with hasattr().
2100
2101Python/C API
2102
2103- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2104 that's already in the dictionary during a PyDict_Next() iteration.
2105 This used to fail occasionally when a dictionary resize operation
2106 could be triggered that would rehash all the keys. All other
2107 modifications to the dictionary are still off-limits during a
2108 PyDict_Next() iteration!
2109
2110- New extended APIs related to passing compiler variables around.
2111
2112- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2113 implement isinstance() and issubclass().
2114
2115- Py_BuildValue() now has a "D" conversion to create a Python complex
2116 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002117
Fred Drake4e262a92001-03-22 18:26:47 +00002118- Extensions types which support weak references must now set the
2119 field allocated for the weak reference machinery to NULL themselves;
2120 this is done to avoid the cost of checking each object for having a
2121 weakly referencable type in PyObject_INIT(), since most types are
2122 not weakly referencable.
2123
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002124- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2125 free variables and cell variables to and from the frame's f_locals.
2126
2127- Variants of several functions defined in pythonrun.h have been added
2128 to support the nested_scopes future statement. The variants all end
2129 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2130 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2131 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002132 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002133
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002134Distutils
2135
2136- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2137 into the release tree.
2138
Tim Peters0e57abf2001-05-02 07:39:38 +00002139- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002140 (an uninstaller, more customization of the installer's display)
2141
2142- from Jack Jansen: added Mac-specific code to generate a dialog for
2143 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002144 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002145 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002146
2147- added 'platforms' and 'keywords' to the set of metadata that can be
2148 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002149
2150- applied patches from Jason Tishler to make the compiler class work with
2151 Cygwin.
2152
2153
Tim Peters2fe289a2001-03-01 22:19:38 +00002154What's New in Python 2.1 beta 1?
2155================================
Tim Petersd66595f2001-02-04 03:09:53 +00002156
2157Core language, builtins, and interpreter
2158
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002159- Following an outcry from the community about the amount of code
2160 broken by the nested scopes feature introduced in 2.1a2, we decided
2161 to make this feature optional, and to wait until Python 2.2 (or at
2162 least 6 months) to make it standard. The option can be enabled on a
2163 per-module basis by adding "from __future__ import nested_scopes" at
2164 the beginning of a module (before any other statements, but after
2165 comments and an optional docstring). See PEP 236 (Back to the
2166 __future__) for a description of the __future__ statement. PEP 227
2167 (Statically Nested Scopes) has been updated to reflect this change,
2168 and to clarify the semantics in a number of endcases.
2169
2170- The nested scopes code, when enabled, has been hardened, and most
2171 bugs and memory leaks in it have been fixed.
2172
2173- Compile-time warnings are now generated for a number of conditions
2174 that will break or change in meaning when nested scopes are enabled:
2175
2176 - Using "from...import *" or "exec" without in-clause in a function
2177 scope that also defines a lambda or nested function with one or
2178 more free (non-local) variables. The presence of the import* or
2179 bare exec makes it impossible for the compiler to determine the
2180 exact set of local variables in the outer scope, which makes it
2181 impossible to determine the bindings for free variables in the
2182 inner scope. To avoid the warning about import *, change it into
2183 an import of explicitly name object, or move the import* statement
2184 to the global scope; to avoid the warning about bare exec, use
2185 exec...in... (a good idea anyway -- there's a possibility that
2186 bare exec will be deprecated in the future).
2187
2188 - Use of a global variable in a nested scope with the same name as a
2189 local variable in a surrounding scope. This will change in
2190 meaning with nested scopes: the name in the inner scope will
2191 reference the variable in the outer scope rather than the global
2192 of the same name. To avoid the warning, either rename the outer
2193 variable, or use a global statement in the inner function.
2194
Neil Schemenauera35c6882001-02-27 04:45:05 +00002195- An optional object allocator has been included. This allocator is
2196 optimized for Python objects and should be faster and use less memory
2197 than the standard system allocator. It is not enabled by default
2198 because of possible thread safety problems. The allocator is only
2199 protected by the Python interpreter lock and it is possible that some
2200 extension modules require a thread safe allocator. The object
2201 allocator can be enabled by providing the "--with-pymalloc" option to
2202 configure.
2203
Tim Petersd66595f2001-02-04 03:09:53 +00002204Standard library
2205
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002206- pyexpat now detects the expat version if expat.h defines it. A
2207 number of additional handlers are provided, which are only available
2208 since expat 1.95. In addition, the methods SetParamEntityParsing and
2209 GetInputContext of Parser objects are available with 1.95.x
2210 only. Parser objects now provide the ordered_attributes and
2211 specified_attributes attributes. A new module expat.model was added,
2212 which offers a number of additional constants if 1.95.x is used.
2213
2214- xml.dom offers the new functions registerDOMImplementation and
2215 getDOMImplementation.
2216
2217- xml.dom.minidom offers a toprettyxml method. A number of DOM
2218 conformance issues have been resolved. In particular, Element now
2219 has an hasAttributes method, and the handling of namespaces was
2220 improved.
2221
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002222- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2223 getting information about live Python code, and pydoc.py, a module
2224 for interactively converting docstrings to HTML or text.
2225 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002226 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002227 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2228 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002229
Tim Peters1eff7962001-03-01 02:31:33 +00002230- New library module difflib.py, primarily packaging the SequenceMatcher
2231 class at the heart of the popular ndiff.py file-comparison tool.
2232
2233- doctest.py (a framework for verifying Python code examples in docstrings)
2234 is now part of the std library.
2235
Tim Petersd66595f2001-02-04 03:09:53 +00002236Windows changes
2237
Guido van Rossume3955a82001-03-02 14:05:59 +00002238- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2239 small GUI that lets you browse the module docstrings using your
2240 default web browser.
2241
Tim Peters1eff7962001-03-01 02:31:33 +00002242- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2243 Platforms) is implemented. See
2244
2245 http://python.sourceforge.net/peps/pep-0235.html
2246
2247 for full details, especially the "Current Lower-Left Semantics" section.
2248 The new Windows import rules are simpler than before:
2249
2250 A. If the PYTHONCASEOK environment variable exists, same as
2251 before: silently accept the first case-insensitive match of any
2252 kind; raise ImportError if none found.
2253
2254 B. Else search sys.path for the first case-sensitive match; raise
2255 ImportError if none found.
2256
2257 The same rules have been implented on other platforms with case-
2258 insensitive but case-preserving filesystems too (including Cygwin, and
2259 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002260
Tim Peters25a9ce32001-02-19 07:06:36 +00002261- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2262 what it's supposed to do (and does do under NT and 2000) via direct
2263 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002264 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002265 all Win9x systems before.
2266
Tim Peters1eff7962001-03-01 02:31:33 +00002267- Build: Subproject _test (effectively) renamed to _testcapi.
2268
Tim Peters2fe289a2001-03-01 22:19:38 +00002269New platforms
2270
2271- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2272 Thanks to Steven Majewski!
2273
2274- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2275 Tishler!
2276
Guido van Rossum9089b272001-03-02 06:49:50 +00002277- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2278 Schwertberger! See RISCOS/README for more information -- it seems
2279 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002280 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002281
Tim Peters25a9ce32001-02-19 07:06:36 +00002282
Tim Petersd7b5e882001-01-25 03:36:26 +00002283What's New in Python 2.1 alpha 2?
2284=================================
Tim Peters40ead762001-01-27 05:35:26 +00002285
Tim Petersd7b5e882001-01-25 03:36:26 +00002286Core language, builtins, and interpreter
2287
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002288- Scopes nest. If a name is used in a function or class, but is not
2289 local, the definition in the nearest enclosing function scope will
2290 be used. One consequence of this change is that lambda statements
2291 could reference variables in the namespaces where the lambda is
2292 defined. In some unusual cases, this change will break code.
2293
2294 In all previous version of Python, names were resolved in exactly
2295 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002296 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002297 function A is defined within a function B, the names bound in B are
2298 not visible in A. The new rules make names bound in B visible in A,
2299 unless A contains a name binding that hides the binding in B.
2300
2301 Section 4.1 of the reference manual describes the new scoping rules
2302 in detail. The test script in Lib/test/test_scope.py demonstrates
2303 some of the effects of the change.
2304
2305 The new rules will cause existing code to break if it defines nested
2306 functions where an outer function has local variables with the same
2307 name as globals or builtins used by the inner function. Example:
2308
2309 def munge(str):
2310 def helper(x):
2311 return str(x)
2312 if type(str) != type(''):
2313 str = helper(str)
2314 return str.strip()
2315
2316 Under the old rules, the name str in helper() is bound to the
2317 builtin function str(). Under the new rules, it will be bound to
2318 the argument named str and an error will occur when helper() is
2319 called.
2320
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002321- The compiler will report a SyntaxError if "from ... import *" occurs
2322 in a function or class scope. The language reference has documented
2323 that this case is illegal, but the compiler never checked for it.
2324 The recent introduction of nested scope makes the meaning of this
2325 form of name binding ambiguous. In a future release, the compiler
2326 may allow this form when there is no possibility of ambiguity.
2327
Tim Peters40ead762001-01-27 05:35:26 +00002328- repr(string) is easier to read, now using hex escapes instead of octal,
2329 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2330
2331 >>> "\texample \r\n" + chr(0) + chr(255)
2332 '\texample \r\n\x00\xff' # in 2.1
2333 '\011example \015\012\000\377' # in 2.0
2334
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002335- Functions are now compared and hashed by identity, not by value, since
2336 the func_code attribute is writable.
2337
Fred Drakefb9d7122001-02-01 20:00:40 +00002338- Weak references (PEP 205) have been added. This involves a few
2339 changes in the core, an extension module (_weakref), and a Python
2340 module (weakref). The weakref module is the public interface. It
2341 includes support for "explicit" weak references, proxy objects, and
2342 mappings with weakly held values.
2343
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002344- A 'continue' statement can now appear in a try block within the body
2345 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002346 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002347
Tim Petersd7b5e882001-01-25 03:36:26 +00002348Standard library
2349
Barry Warsaw30dbd142001-01-31 22:14:01 +00002350- mailbox.py now has a new class, PortableUnixMailbox which is
2351 identical to UnixMailbox but uses a more portable scheme for
2352 determining From_ separators. Also, the constructors for all the
2353 classes in this module have a new optional `factory' argument, which
2354 is a callable used when new message classes must be instantiated by
2355 the next() method.
2356
Tim Petersd7b5e882001-01-25 03:36:26 +00002357- random.py is now self-contained, and offers all the functionality of
2358 the now-deprecated whrandom.py. See the docs for details. random.py
2359 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002360 and restoring the internal state of the generator; and jumpahead(n),
2361 for quickly forcing the internal state to be the same as if n calls to
2362 random() had been made. The latter is particularly useful for multi-
2363 threaded programs, creating one instance of the random.Random() class for
2364 each thread, then using .jumpahead() to force each instance to use a
2365 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002366
Tim Peters0de88fc2001-02-01 04:59:18 +00002367- random.py's seed() function is new. For bit-for-bit compatibility with
2368 prior releases, use the whseed function instead. The new seed function
2369 addresses two problems: (1) The old function couldn't produce more than
2370 about 2**24 distinct internal states; the new one about 2**45 (the best
2371 that can be done in the Wichmann-Hill generator). (2) The old function
2372 sometimes produced identical internal states when passed distinct
2373 integers, and there was no simple way to predict when that would happen;
2374 the new one guarantees to produce distinct internal states for all
2375 arguments in [0, 27814431486576L).
2376
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002377- The socket module now supports raw packets on Linux. The socket
2378 family is AF_PACKET.
2379
Tim Peters9ea17ac2001-02-02 05:57:15 +00002380- test_capi.py is a start at running tests of the Python C API. The tests
2381 are implemented by the new Modules/_testmodule.c.
2382
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002383- A new extension module, _symtable, provides provisional access to the
2384 internal symbol table used by the Python compiler. A higher-level
2385 interface will be added on top of _symtable in a future release.
2386
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002387- Removed the obsolete soundex module.
2388
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002389- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2390 the isSameNode method; NamedNodeMap the get method.
2391
2392- xml.sax.expatreader supports the lexical handler property; it
2393 generates comment, startCDATA, and endCDATA events.
2394
Tim Petersee826f82001-01-31 19:39:44 +00002395Windows changes
2396
2397- Build procedure: the zlib project is built in a different way that
2398 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002399 the zlib binary used. See PCbuild\readme.txt for details. Your old
2400 zlib-related directories can be deleted; you'll need to download fresh
2401 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002402
Tim Peters9ea17ac2001-02-02 05:57:15 +00002403- Build: New subproject _test for the benefit of test_capi.py (see above).
2404
Tim Petersb16c56f2001-02-02 21:24:51 +00002405- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2406 interface to some Python compiler internals).
2407
2408- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002409 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002410
Tim Petersa3a3a032000-11-30 05:22:44 +00002411What's New in Python 2.1 alpha 1?
2412=================================
2413
2414Core language, builtins, and interpreter
2415
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002416- There is a new Unicode companion to the PyObject_Str() API
2417 called PyObject_Unicode(). It behaves in the same way as the
2418 former, but assures that the returned value is an Unicode object
2419 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002420
Guido van Rossumf98eda02001-01-17 15:54:45 +00002421- The comparison operators support "rich comparison overloading" (PEP
2422 207). C extension types can provide a rich comparison function in
2423 the new tp_richcompare slot in the type object. The cmp() function
2424 and the C function PyObject_Compare() first try the new rich
2425 comparison operators before trying the old 3-way comparison. There
2426 is also a new C API PyObject_RichCompare() (which also falls back on
2427 the old 3-way comparison, but does not constrain the outcome of the
2428 rich comparison to a Boolean result).
2429
2430 The rich comparison function takes two objects (at least one of
2431 which is guaranteed to have the type that provided the function) and
2432 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2433 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2434 object, which may be NotImplemented (in which case the tp_compare
2435 slot function is used as a fallback, if defined).
2436
2437 Classes can overload individual comparison operators by defining one
2438 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002439 __ge__. There are no explicit "reflected argument" versions of
2440 these; instead, __lt__ and __gt__ are each other's reflection,
2441 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2442 reflection (similar at the C level). No other implications are
2443 made; in particular, Python does not assume that == is the Boolean
2444 inverse of !=, or that < is the Boolean inverse of >=. This makes
2445 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002446
2447 Classes or types that want to implement (in)equality tests but not
2448 the ordering operators (i.e. unordered types) should implement ==
2449 and !=, and raise an error for the ordering operators.
2450
Guido van Rossuma88479f2001-01-18 14:28:08 +00002451 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002452 Boolean; e.g. a matrix type might want to return a matrix of bits
2453 for A < B, giving elementwise comparisons. Such types should ensure
2454 that any interpretation of their value in a Boolean context raises
2455 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2456 at the C level) to always raise an exception.
2457
Guido van Rossuma88479f2001-01-18 14:28:08 +00002458- Complex numbers use rich comparisons to define == and != but raise
2459 an exception for <, <=, > and >=. Unfortunately, this also means
2460 that cmp() of two complex numbers raises an exception when the two
2461 numbers differ. Since it is not mathematically meaningful to compare
2462 complex numbers except for equality, I hope that this doesn't break
2463 too much code.
2464
Tim Peters3389f192001-02-18 08:48:49 +00002465- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002466 not defined by the language, other than that it's arbitrary but
2467 consistent (see the Reference Manual). An implementation detail changed
2468 in 2.1a1 such that None now compares less than any other object. Code
2469 relying on this new behavior (like code that relied on the previous
2470 behavior) does so at its own risk.
2471
Barry Warsaw573b5412001-01-15 20:43:18 +00002472- Functions and methods now support getting and setting arbitrarily
2473 named attributes (PEP 232). Functions have a new __dict__
2474 (a.k.a. func_dict) which hold the function attributes. Methods get
2475 and set attributes on their underlying im_func. It is a TypeError
2476 to set an attribute on a bound method.
2477
Guido van Rossum051e3352001-01-15 19:11:10 +00002478- The xrange() object implementation has been improved so that
2479 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2480 limitation that in this case len(xrange(sys.maxint)) can't be
2481 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2482 work fine as long as the index i doesn't actually reach 2**31.
2483 (Python uses regular ints for sequence and string indices; fixing
2484 that is much more work.)
2485
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002486- Two changes to from...import:
2487
Guido van Rossumba381232001-02-03 15:06:40 +00002488 1) "from M import X" now works even if (after loading module M)
2489 sys.modules['M'] is not a real module; it's basically a getattr()
2490 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002491
2492 2) "from M import *" now looks for M.__all__ to decide which names to
2493 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2494 filters out names starting with '_' as before. Whether or not
2495 __all__ exists, there's no restriction on the type of M.
2496
Guido van Rossumf61f1662001-01-10 20:13:55 +00002497- File objects have a new method, xreadlines(). This is the fastest
2498 way to iterate over all lines in a file:
2499
2500 for line in file.xreadlines():
2501 ...do something to line...
2502
2503 See the xreadlines module (mentioned below) for how to do this for
2504 other file-like objects.
2505
2506- Even if you don't use file.xreadlines(), you may expect a speedup on
2507 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002508 quite a bit in platform-specific ways: on systems (like Linux) that
2509 support flockfile(), getc_unlocked(), and funlockfile(), those are
2510 used by default. On systems (like Windows) without getc_unlocked(),
2511 a complicated (but still thread-safe) method using fgets() is used by
2512 default.
2513
Tim Petersd52269b2001-01-25 06:23:18 +00002514 You can force use of the fgets() method by #define'ing
2515 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002516 getc_unlocked()).
2517
Tim Petersd52269b2001-01-25 06:23:18 +00002518 You can force fgets() not to be used by #define'ing
2519 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002520 test_bufio.py fails -- and let us know if it does!).
2521
2522- In addition, the fileinput module, while still slower than the other
2523 methods on most platforms, has been sped up too, by using
2524 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002525
2526- Support for run-time warnings has been added, including a new
2527 command line option (-W) to specify the disposition of warnings.
2528 See the description of the warnings module below.
2529
2530- Extensive changes have been made to the coercion code. This mostly
2531 affects extension modules (which can now implement mixed-type
2532 numerical operators without having to use coercion), but
2533 occasionally, in boundary cases the coercion semantics have changed
2534 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002535 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002536 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002537 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002538
Guido van Rossumf98eda02001-01-17 15:54:45 +00002539- In connection with the coercion changes, a new built-in singleton
2540 object, NotImplemented is defined. This can be returned for
2541 operations that wish to indicate they are not implemented for a
2542 particular combination of arguments. From C, this is
2543 Py_NotImplemented.
2544
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002545- The interpreter accepts now bytecode files on the command line even
2546 if they do not have a .pyc or .pyo extension. On Linux, after executing
2547
Martin v. Löwise214baa2001-02-04 22:37:56 +00002548import imp,sys,string
2549magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2550reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2551open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002552
2553 any byte code file can be used as an executable (i.e. as an argument
2554 to execve(2)).
2555
Tim Peters9940b802000-12-01 07:59:35 +00002556- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002557 character. In 1.6 and earlier, they never produced a sign,
2558 and raised an error if the value of the long was too large
2559 to fit in a Python int. In 2.0, they produced a sign if and
2560 only if too large to fit in an int. This was inconsistent
2561 across platforms (because the size of an int varies across
2562 platforms), and inconsistent with hex() and oct(). Example:
2563
2564 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002565 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002566 'ffffffbe' # in 2.0 and before, on 32-bit machines
2567 >>> hex(-0x42L)
2568 '-0x42L' # in all versions of Python
2569
Tim Peters9940b802000-12-01 07:59:35 +00002570 The behavior of %d formats for negative Python longs remains
2571 the same as in 2.0 (although in 1.6 and before, they raised
2572 an error if the long didn't fit in a Python int).
2573
2574 %u formats don't make sense for Python longs, but are allowed
2575 and treated the same as %d in 2.1. In 2.0, a negative long
2576 formatted via %u produced a sign if and only if too large to
2577 fit in an int. In 1.6 and earlier, a negative long formatted
2578 via %u raised an error if it was too big to fit in an int.
2579
Guido van Rossum3661d392000-12-12 22:10:31 +00002580- Dictionary objects have an odd new method, popitem(). This removes
2581 an arbitrary item from the dictionary and returns it (in the form of
2582 a (key, value) pair). This can be useful for algorithms that use a
2583 dictionary as a bag of "to do" items and repeatedly need to pick one
2584 item. Such algorithms normally end up running in quadratic time;
2585 using popitem() they can usually be made to run in linear time.
2586
Tim Peters36cdad12000-12-29 02:06:45 +00002587Standard library
2588
Thomas Woutersfe385252001-01-19 23:16:56 +00002589- In the time module, the time argument to the functions strftime,
2590 localtime, gmtime, asctime and ctime is now optional, defaulting to
2591 the current time (in the local timezone).
2592
Guido van Rossumda91f222001-01-15 16:36:08 +00002593- The ftplib module now defaults to passive mode, which is deemed a
2594 more useful default given that clients are often inside firewalls
2595 these days. Note that this could break if ftplib is used to connect
2596 to a *server* that is inside a firewall, from outside; this is
2597 expected to be a very rare situation. To fix that, you can call
2598 ftp.set_pasv(0).
2599
Martin v. Löwis10a27872001-01-13 09:54:41 +00002600- The module site now treats .pth files not only for path configuration,
2601 but also supports extensions to the initialization code: Lines starting
2602 with import are executed.
2603
Guido van Rossumf61f1662001-01-10 20:13:55 +00002604- There's a new module, warnings, which implements a mechanism for
2605 issuing and filtering warnings. There are some new built-in
2606 exceptions that serve as warning categories, and a new command line
2607 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2608 turns warnings into errors). warnings.warn(message[, category])
2609 issues a warning message; this can also be called from C as
2610 PyErr_Warn(category, message).
2611
2612- A new module xreadlines was added. This exports a single factory
2613 function, xreadlines(). The intention is that this code is the
2614 absolutely fastest way to iterate over all lines in an open
2615 file(-like) object:
2616
2617 import xreadlines
2618 for line in xreadlines.xreadlines(file):
2619 ...do something to line...
2620
2621 This is equivalent to the previous the speed record holder using
2622 file.readlines(sizehint). Note that if file is a real file object
2623 (as opposed to a file-like object), this is equivalent:
2624
2625 for line in file.xreadlines():
2626 ...do something to line...
2627
Tim Peters36cdad12000-12-29 02:06:45 +00002628- The bisect module has new functions bisect_left, insort_left,
2629 bisect_right and insort_right. The old names bisect and insort
2630 are now aliases for bisect_right and insort_right. XXX_right
2631 and XXX_left methods differ in what happens when the new element
2632 compares equal to one or more elements already in the list: the
2633 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002634 right. Code that doesn't care where equal elements end up should
2635 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002636
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002637- The new curses.panel module wraps the panel library that forms part
2638 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2639
Guido van Rossumf61f1662001-01-10 20:13:55 +00002640- The SocketServer module now sets the allow_reuse_address flag by
2641 default in the TCPServer class.
2642
2643- A new function, sys._getframe(), returns the stack frame pointer of
2644 the caller. This is intended only as a building block for
2645 higher-level mechanisms such as string interpolation.
2646
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002647- The pyexpat module supports a number of new handlers, which are
2648 available only in expat 1.2. If invocation of a callback fails, it
2649 will report an additional frame in the traceback. Parser objects
2650 participate now in garbage collection. If expat reports an unknown
2651 encoding, pyexpat will try to use a Python codec; that works only
2652 for single-byte charsets. The parser type objects is exposed as
2653 XMLParserObject.
2654
2655- xml.dom now offers standard definitions for symbolic node type and
2656 exception code constants, and a hierarchy of DOM exceptions. minidom
2657 was adjusted to use them.
2658
2659- The conformance of xml.dom.minidom to the DOM specification was
2660 improved. It detects a number of additional error cases; the
2661 previous/next relationship works even when the tree is modified;
2662 Node supports the normalize() method; NamedNodeMap, DocumentType and
2663 DOMImplementation classes were added; Element supports the
2664 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2665 method.
2666
Guido van Rossumf61f1662001-01-10 20:13:55 +00002667Build issues
2668
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002669- For Unix (and Unix-compatible) builds, configuration and building of
2670 extension modules is now greatly automated. Rather than having to
2671 edit the Modules/Setup file to indicate which modules should be
2672 built and where their include files and libraries are, a
2673 distutils-based setup.py script now takes care of building most
2674 extension modules. All extension modules built this way are built
2675 as shared libraries. Only a few modules that must be linked
2676 statically are still listed in the Setup file; you won't need to
2677 edit their configuration.
2678
2679- Python should now build out of the box on Cygwin. If it doesn't,
2680 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002681
2682- Python now always uses its own (renamed) implementation of getopt()
2683 -- there's too much variation among C library getopt()
2684 implementations.
2685
2686- C++ compilers are better supported; the CXX macro is always set to a
2687 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002688
Tim Petersd92dfe02000-12-12 01:18:41 +00002689Windows changes
2690
2691- select module: By default under Windows, a select() call
2692 can specify no more than 64 sockets. Python now boosts
2693 this Microsoft default to 512. If you need even more than
2694 that, see the MS docs (you'll need to #define FD_SETSIZE
2695 and recompile Python from source).
2696
Guido van Rossumf61f1662001-01-10 20:13:55 +00002697- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2698 subdirectory is no more!
2699
Tim Petersa3a3a032000-11-30 05:22:44 +00002700
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002701What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002702=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002703
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002704Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002705changes are in the file HISTORY. If you are making the jump directly
2706from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2707HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002708
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002709Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2710the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2711http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002712
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002713--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002714
2715======================================================================
2716
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002717What's new in 2.0 (since release candidate 1)?
2718==============================================
2719
2720Standard library
2721
2722- The copy_reg module was modified to clarify its intended use: to
2723 register pickle support for extension types, not for classes.
2724 pickle() will raise a TypeError if it is passed a class.
2725
2726- Fixed a bug in gettext's "normalize and expand" code that prevented
2727 it from finding an existing .mo file.
2728
2729- Restored support for HTTP/0.9 servers in httplib.
2730
Tim Peters989b7b92000-10-16 20:24:53 +00002731- The math module was changed to stop raising OverflowError in case of
2732 underflow, and return 0 instead in underflow cases. Whether Python
2733 used to raise OverflowError in case of underflow was platform-
2734 dependent (it did when the platform math library set errno to ERANGE
2735 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002736
2737- Fixed a bug in StringIO that occurred when the file position was not
2738 at the end of the file and write() was called with enough data to
2739 extend past the end of the file.
2740
2741- Fixed a bug that caused Tkinter error messages to get lost on
2742 Windows. The bug was fixed by replacing direct use of
2743 interp->result with Tcl_GetStringResult(interp).
2744
2745- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2746 redirect response.
2747
2748- Several changes were made to distutils: Some debugging code was
2749 removed from util. Fixed the installer used when an external zip
2750 program (like WinZip) is not found; the source code for this
2751 installer is in Misc/distutils. check_lib() was modified to behave
2752 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2753 test for whether installed modules are on sys.path was changed to
2754 use both normcase() and normpath().
2755
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002756- Several minor bugs were fixed in the xml package (the minidom,
2757 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002758
2759- The regression test driver (regrtest.py) behavior when invoked with
2760 -l changed: It now reports a count of objects that are recognized as
2761 garbage but not freed by the garbage collector.
2762
Tim Peters989b7b92000-10-16 20:24:53 +00002763- The regression test for the math module was changed to test
2764 exceptional behavior when the test is run in verbose mode. Python
2765 cannot yet guarantee consistent exception behavior across platforms,
2766 so the exception part of test_math is run only in verbose mode, and
2767 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002768
2769Internals
2770
2771- PyOS_CheckStack() has been disabled on Win64, where it caused
2772 test_sre to fail.
2773
2774Build issues
2775
2776- Changed compiler flags, so that gcc is always invoked with -Wall and
2777 -Wstrict-prototypes. Users compiling Python with GCC should see
2778 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002779 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002780 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002781
Tim Petersa3a3a032000-11-30 05:22:44 +00002782- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002783
2784Tools and other miscellany
2785
2786- The compiler in Tools/compiler was updated to support the new
2787 language features introduced in 2.0: extended print statement, list
2788 comprehensions, and augmented assignments. The new compiler should
2789 also be backwards compatible with Python 1.5.2; the compiler will
2790 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002791 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002792
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002793What's new in 2.0 release candidate 1 (since beta 2)?
2794=====================================================
2795
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002796What is release candidate 1?
2797
2798We believe that release candidate 1 will fix all known bugs that we
2799intend to fix for the 2.0 final release. This release should be a bit
2800more stable than the previous betas. We would like to see even more
2801widespread testing before the final release, so we are producing this
2802release candidate. The final release will be exactly the same unless
2803any show-stopping (or brown bag) bugs are found by testers of the
2804release candidate.
2805
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002806All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002807to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002808
2809Core language, builtins, and interpreter
2810
2811- A bug that caused crashes when __coerce__ was used with augmented
2812 assignment, e.g. +=, was fixed.
2813
2814- Raise ZeroDivisionError when raising zero to a negative number,
2815 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2816 power operator and the result of math.pow(0.0, -2.0) will vary by
2817 platform. On Linux, it raises a ValueError.
2818
2819- A bug in Unicode string interpolation was fixed that occasionally
2820 caused errors with formats including "%%". For example, the
2821 following expression "%% %s" % u"abc" no longer raises a TypeError.
2822
2823- Compilation of deeply nested expressions raises MemoryError instead
2824 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2825
2826- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2827 rendering them useless. They are now written in binary mode again.
2828
2829Standard library
2830
2831- Keyword arguments are now accepted for most pattern and match object
2832 methods in SRE, the standard regular expression engine.
2833
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002834- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002835 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002836
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002837- Several bugs in the Unicode handling and error handling in _tkinter
2838 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002839
2840- Fix memory management errors in Merge() and Tkapp_Call() routines.
2841
2842- Several changes were made to cStringIO to make it compatible with
2843 the file-like object interface and with StringIO. If operations are
2844 performed on a closed object, an exception is raised. The truncate
2845 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002846 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002847
2848- There were many changes made to the linuxaudiodev module and its
2849 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002850 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002851
2852 Note that this module is named poorly, because it should work
2853 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002854 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002855
2856 The module now raises exceptions when errors occur instead of
2857 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2858 audio) and defines a getptr() method that calls the
2859 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2860
2861- The library_version attribute, introduced in an earlier beta, was
2862 removed because it can not be supported with early versions of the C
2863 readline library, which provides no way to determine the version at
2864 compile-time.
2865
2866- The binascii module is now enabled on Win64.
2867
Tim Peters46446d62000-10-09 21:19:31 +00002868- tokenize.py no longer suffers "recursion depth" errors when parsing
2869 programs with very long string literals.
2870
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002871Internals
2872
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002873- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002874 which is called when the interpreter starts up to determine where
2875 the standard library is installed. These vulnerabilities affect all
2876 previous versions of Python and can be exploited by setting very
2877 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2878 setuid Python script, although use of the wrapper in
2879 Misc/setuid-prog.c will eliminate the vulnerability.
2880
2881- Fixed garbage collection bugs in instance creation that were
2882 triggered when errors occurred during initialization. The solution,
2883 applied in cPickle and in PyInstance_New(), is to call
2884 PyObject_GC_Init() after the initialization of the object's
2885 container attributes is complete.
2886
2887- pyexpat adds definitions of PyModule_AddStringConstant and
2888 PyModule_AddObject if the Python version is less than 2.0, which
2889 provides compatibility with PyXML on Python 1.5.2.
2890
2891- If the platform has a bogus definition for LONG_BIT (the number of
2892 bits in a long), an error will be reported at compile time.
2893
2894- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2895 collection crashes and possibly other, unreported crashes.
2896
2897- Fixed a memory leak in _PyUnicode_Fini().
2898
2899Build issues
2900
2901- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002902 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002903 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002904
2905- The mmap.PAGESIZE constant is now initialized using sysconf when
2906 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2907
2908- The md5 file should now compile on all platforms.
2909
2910- The select module now compiles on platforms that do not define
2911 POLLRDNORM and related constants.
2912
2913- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002914 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002915
Jeremy Hylton10921202000-10-09 18:34:12 +00002916- BeOS: A number of changes were made to the build and installation
2917 process. ar-fake now operates on a directory of object files.
2918 dl_export.h is gone, and its macros now appear on the mwcc command
2919 line during build on PPC BeOS.
2920
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002921- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002922 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002923
2924- Cygwin: Support for shared libraries, Tkinter, and sockets.
2925
2926- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2927
2928Tools and other miscellany
2929
2930- Removed debugging prints from main used with freeze.
2931
Tim Peters46446d62000-10-09 21:19:31 +00002932- IDLE auto-indent no longer crashes when it encounters Unicode
2933 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002934
2935What's new in 2.0 beta 2 (since beta 1)?
2936========================================
2937
2938Core language, builtins, and interpreter
2939
Tim Peters482c0212000-09-26 06:33:09 +00002940- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002941 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002942
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002943- Add -h and -V command line options to print the usage message and
2944 Python version number and exit immediately.
2945
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002946- eval() and exec accept Unicode objects as code parameters.
2947
2948- getattr() and setattr() now also accept Unicode objects for the
2949 attribute name, which are converted to strings using the default
2950 encoding before lookup.
2951
2952- Multiplication on string and Unicode now does proper bounds
2953 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2954 string is too long."
2955
2956- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002957 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002958
Jeremy Hylton1b618592000-09-26 05:32:36 +00002959
2960Standard library and extensions
2961
Guido van Rossum5b08f132001-04-16 02:05:23 +00002962- socket module: the OpenSSL code now adds support for RAND_status()
2963 and EGD (Entropy Gathering Device).
2964
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002965- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002966 argument checking; it still takes no arguments.
2967
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002968- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002969
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002970- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002971
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002972- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002973
2974- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002975 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002976
2977- copy: Copy Unicode objects atomically.
2978
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002979- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002980
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002981- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002982
Fred Drake67233bc2000-09-26 16:40:27 +00002983- dbm: Add get() and setdefault() methods to dbm object. Add constant
2984 `library' to module that names the library used. Added doc strings
2985 and method names to error messages. Uses configure to determine
2986 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2987 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002988
2989- distutils: Update to version 0.9.3.
2990
2991- dl: Add several dl.RTLD_ constants.
2992
2993- fpectl: Now supported on FreeBSD.
2994
2995- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2996 found by the collector will be saved in gc.garbage. This is useful
2997 for debugging a program that creates reference cycles.
2998
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002999- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003000 of HTTP class. Do not close socket on zero-length response. Do not
3001 crash when server sends invalid content-length header.
3002
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003003- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003004
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003005- marshal: When reading a short, sign-extend on platforms where shorts
3006 are bigger than 16 bits. When reading a long, repair the unportable
3007 sign extension that was being done for 64-bit machines. (It assumed
3008 that signed right shift sign-extends.)
3009
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003010- operator: Add contains(), invert(), __invert__() as aliases for
3011 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003012
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003013- os: Add support for popen2() and popen3() on all platforms where
3014 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003015
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003016- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003017 clicking on a file in Explorer (or passing the file name to the
3018 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003019
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003020- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003021 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003022
3023- pickle: Now raises ValueError when an invalid pickle that contains
3024 a non-string repr where a string repr was expected. This behavior
3025 matches cPickle.
3026
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003027- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003028
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003029- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003030
3031- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003032 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003033 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003034
3035- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003036 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003037
3038- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003039 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003040 few cycles during startup since the first call to
3041 setdefaultencoding() will initialize the codec registry and the
3042 encodings package.
3043
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003044- socket: Support for size hint in readlines() method of object returned
3045 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003046
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003047- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003048 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003049 is followed by whitespace.
3050
Tim Petersa3a3a032000-11-30 05:22:44 +00003051- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003052
3053- struct: Check ranges for bytes and shorts.
3054
3055- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003056 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003057
3058- Tkinter: Image objects are now guaranteed to have unique ids. Set
3059 event.delta to zero if Tk version doesn't support mousewheel.
3060 Removed some debugging prints.
3061
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003062- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003063
Fred Drake67233bc2000-09-26 16:40:27 +00003064- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003065 which works around a bug in Norton AntiVirus 2000 that leads directly
3066 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003067
3068- xml: New version detection code allows PyXML to override standard
3069 XML package if PyXML version is greater than 0.6.1.
3070
Fred Drake64bb3802000-09-26 16:21:35 +00003071- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3072 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3073 tree only for nodes which are sufficiently interesting to a specific
3074 application. Does not provide the HTML-specific extensions. Still
3075 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003076
Fred Drake64bb3802000-09-26 16:21:35 +00003077- xml.sax: SAX 2 support for Python, including all the handler
3078 interfaces needed to process XML 1.0 compliant XML. Some
3079 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003080
Fred Drake64bb3802000-09-26 16:21:35 +00003081- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3082 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003083
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003084
Jeremy Hylton1b618592000-09-26 05:32:36 +00003085C API
3086
3087- Add three new convenience functions for module initialization --
3088 PyModule_AddObject(), PyModule_AddIntConstant(), and
3089 PyModule_AddStringConstant().
3090
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003091- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003092 removed and add #error to Python.h if NULL isn't defined after
3093 #include of stdio.h.
3094
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003095- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003096 backwards compatibility (at the source level) with old extensions.
3097
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003098- A wrapper API was added for signal() and sigaction(). Instead of
3099 either function, always use PyOS_getsig() to get a signal handler
3100 and PyOS_setsig() to set one. A new convenience typedef
3101 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003102
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003103- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003104 internal data buffer and size of a string object -- or the default
3105 encoded version of a Unicode object.
3106
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003107- PyString_Size() and PyString_AsString() accept Unicode objects.
3108
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003109- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003110 exists). INT_MAX and LONG_MAX will always be defined, even if
3111 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003112
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003113- PyFloat_FromString takes a second argument, pend, that was
3114 effectively useless. It is now officially useless but preserved for
3115 backwards compatibility. If the pend argument is not NULL, *pend is
3116 set to NULL.
3117
3118- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3119 for the attribute name. See note on getattr() above.
3120
3121- A few bug fixes to argument processing for Unicode.
3122 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3123 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3124 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003125 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003126
3127- Py_BuildValue accepts B format (for bgen-generated code).
3128
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003129
Jeremy Hylton1b618592000-09-26 05:32:36 +00003130Internals
3131
3132- On Unix, fix code for finding Python installation directory so that
3133 it works when argv[0] is a relative path.
3134
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003135- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003136 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003137 rather than by generating a copy of the object.
3138
Tim Peters482c0212000-09-26 06:33:09 +00003139- Several of the internal Unicode tables are much smaller now, and
3140 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003141
Jeremy Hylton97693b02000-09-26 17:42:51 +00003142- In the garbage collector: Fixed bug in collection of tuples. Fixed
3143 bug that caused some instances to be removed from the container set
3144 while they were still live. Fixed parsing in gc.set_debug() for
3145 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003146
3147- Fixed refcount problem in instance deallocation that only occurred
3148 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3149
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003150- On Windows, getpythonregpath is now protected against null data in
3151 registry key.
3152
3153- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003154 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003155
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003156
Jeremy Hylton1b618592000-09-26 05:32:36 +00003157Build and platform-specific issues
3158
3159- Better support of GNU Pth via --with-pth configure option.
3160
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003161- Python/C API now properly exposed to dynamically-loaded extension
3162 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003163
3164- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3165 Don't define MS_SYNC to be zero when it is undefined. Added missing
3166 prototypes in posixmodule.c.
3167
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003168- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003169 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003170
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003171- Fix largefile support on older NetBSD systems and OpenBSD by adding
3172 define for TELL64.
3173
3174
3175Tools and other miscellany
3176
3177- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3178
3179- freeze: The modulefinder now works with 2.0 opcodes.
3180
Tim Petersa3a3a032000-11-30 05:22:44 +00003181- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003182 Move hackery of sys.argv until after the Tk instance has been
3183 created, which allows the application-specific Tkinter
3184 initialization to be executed if present; also pass an explicit
3185 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003186
Jeremy Hylton1b618592000-09-26 05:32:36 +00003187
3188What's new in 2.0 beta 1?
3189=========================
3190
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003191Source Incompatibilities
3192------------------------
3193
3194None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3195such as single-argument append(), connect() and bind(), and changes to
3196str(long) and repr(float).
3197
3198
3199Binary Incompatibilities
3200------------------------
3201
3202- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3203with Python 2.0; these extensions will have to be rebuilt for Python
32042.0.
3205
3206- On Windows, attempting to import a third party extension built for
3207Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3208can do about this. Check your PYTHONPATH environment variable!
3209
3210- Python bytecode files (*.pyc and *.pyo) are not compatible between
3211releases.
3212
3213
3214Overview of Changes Since 1.6
3215-----------------------------
3216
3217There are many new modules (including brand new XML support through
3218the xml package, and i18n support through the gettext module); a list
3219of all new modules is included below. Lots of bugs have been fixed.
3220
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003221The process for making major new changes to the language has changed
3222since Python 1.6. Enhancements must now be documented by a Python
3223Enhancement Proposal (PEP) before they can be accepted.
3224
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003225There are several important syntax enhancements, described in more
3226detail below:
3227
3228 - Augmented assignment, e.g. x += 1
3229
3230 - List comprehensions, e.g. [x**2 for x in range(10)]
3231
3232 - Extended import statement, e.g. import Module as Name
3233
3234 - Extended print statement, e.g. print >> file, "Hello"
3235
3236Other important changes:
3237
3238 - Optional collection of cyclical garbage
3239
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003240Python Enhancement Proposal (PEP)
3241---------------------------------
3242
3243PEP stands for Python Enhancement Proposal. A PEP is a design
3244document providing information to the Python community, or describing
3245a new feature for Python. The PEP should provide a concise technical
3246specification of the feature and a rationale for the feature.
3247
3248We intend PEPs to be the primary mechanisms for proposing new
3249features, for collecting community input on an issue, and for
3250documenting the design decisions that have gone into Python. The PEP
3251author is responsible for building consensus within the community and
3252documenting dissenting opinions.
3253
3254The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003255
3256Augmented Assignment
3257--------------------
3258
3259This must have been the most-requested feature of the past years!
3260Eleven new assignment operators were added:
3261
Guido van Rossume905e952000-09-05 12:42:46 +00003262 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003263
3264For example,
3265
3266 A += B
3267
3268is similar to
3269
3270 A = A + B
3271
3272except that A is evaluated only once (relevant when A is something
3273like dict[index].attr).
3274
3275However, if A is a mutable object, A may be modified in place. Thus,
3276if A is a number or a string, A += B has the same effect as A = A+B
3277(except A is only evaluated once); but if a is a list, A += B has the
3278same effect as A.extend(B)!
3279
3280Classes and built-in object types can override the new operators in
3281order to implement the in-place behavior; the not-in-place behavior is
3282used automatically as a fallback when an object doesn't implement the
3283in-place behavior. For classes, the method name is derived from the
3284method name for the corresponding not-in-place operator by inserting
3285an 'i' in front of the name, e.g. __iadd__ implements in-place
3286__add__.
3287
3288Augmented assignment was implemented by Thomas Wouters.
3289
3290
3291List Comprehensions
3292-------------------
3293
3294This is a flexible new notation for lists whose elements are computed
3295from another list (or lists). The simplest form is:
3296
3297 [<expression> for <variable> in <sequence>]
3298
Guido van Rossum56db0952000-09-06 23:34:25 +00003299For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003300This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003301
3302You can also add a condition:
3303
3304 [<expression> for <variable> in <sequence> if <condition>]
3305
3306For example, [w for w in words if w == w.lower()] would yield the list
3307of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003308than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003309
3310You can also have nested for loops and more than one 'if' clause. For
3311example, here's a function that flattens a sequence of sequences::
3312
3313 def flatten(seq):
3314 return [x for subseq in seq for x in subseq]
3315
3316 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3317
3318This prints
3319
3320 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3321
3322List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003323Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003324
3325
3326Extended Import Statement
3327-------------------------
3328
3329Many people have asked for a way to import a module under a different
3330name. This can be accomplished like this:
3331
3332 import foo
3333 bar = foo
3334 del foo
3335
3336but this common idiom gets old quickly. A simple extension of the
3337import statement now allows this to be written as follows:
3338
3339 import foo as bar
3340
3341There's also a variant for 'from ... import':
3342
3343 from foo import bar as spam
3344
3345This also works with packages; e.g. you can write this:
3346
3347 import test.regrtest as regrtest
3348
3349Note that 'as' is not a new keyword -- it is recognized only in this
3350context (this is only possible because the syntax for the import
3351statement doesn't involve expressions).
3352
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003353Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003354
3355
3356Extended Print Statement
3357------------------------
3358
3359Easily the most controversial new feature, this extension to the print
3360statement adds an option to make the output go to a different file
3361than the default sys.stdout.
3362
3363For example, to write an error message to sys.stderr, you can now
3364write:
3365
3366 print >> sys.stderr, "Error: bad dog!"
3367
3368As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003369evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003370
3371 print >> None, "Hello world"
3372
3373is equivalent to
3374
3375 print "Hello world"
3376
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003377Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003378
3379
3380Optional Collection of Cyclical Garbage
3381---------------------------------------
3382
3383Python is now equipped with a garbage collector that can hunt down
3384cyclical references between Python objects. It's no replacement for
3385reference counting; in fact, it depends on the reference counts being
3386correct, and decides that a set of objects belong to a cycle if all
3387their reference counts can be accounted for from their references to
3388each other. This devious scheme was first proposed by Eric Tiedemann,
3389and brought to implementation by Neil Schemenauer.
3390
3391There's a module "gc" that lets you control some parameters of the
3392garbage collection. There's also an option to the configure script
3393that lets you enable or disable the garbage collection. In 2.0b1,
3394it's on by default, so that we (hopefully) can collect decent user
3395experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003396performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003397off by default in the final 2.0 release.
3398
3399
3400Smaller Changes
3401---------------
3402
3403A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3404map(None, seq1, seq2, ...) when the sequences have the same length;
3405i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3406the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003407zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003408
3409sys.version_info is a tuple (major, minor, micro, level, serial).
3410
3411Dictionaries have an odd new method, setdefault(key, default).
3412dict.setdefault(key, default) returns dict[key] if it exists; if not,
3413it sets dict[key] to default and returns that value. Thus:
3414
3415 dict.setdefault(key, []).append(item)
3416
3417does the same work as this common idiom:
3418
3419 if not dict.has_key(key):
3420 dict[key] = []
3421 dict[key].append(item)
3422
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003423There are two new variants of SyntaxError that are raised for
3424indentation-related errors: IndentationError and TabError.
3425
3426Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3427escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003428
3429The limits on the size of expressions and file in Python source code
3430have been raised from 2**16 to 2**32. Previous versions of Python
3431were limited because the maximum argument size the Python VM accepted
3432was 2**16. This limited the size of object constructor expressions,
3433e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3434limit was raised thanks to a patch by Charles Waldman that effectively
3435fixes the problem. It is now much more likely that you will be
3436limited by available memory than by an arbitrary limit in Python.
3437
3438The interpreter's maximum recursion depth can be modified by Python
3439programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3440limit is the maximum number of recursive calls that can be made by
3441Python code. The limit exists to prevent infinite recursion from
3442overflowing the C stack and causing a core dump. The default value is
34431000. The maximum safe value for a particular platform can be found
3444by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003445
3446New Modules and Packages
3447------------------------
3448
3449atexit - for registering functions to be called when Python exits.
3450
3451imputil - Greg Stein's alternative API for writing custom import
3452hooks.
3453
3454pyexpat - an interface to the Expat XML parser, contributed by Paul
3455Prescod.
3456
3457xml - a new package with XML support code organized (so far) in three
3458subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3459would fill a volume. There's a special feature whereby a
3460user-installed package named _xmlplus overrides the standard
3461xmlpackage; this is intended to give the XML SIG a hook to distribute
3462backwards-compatible updates to the standard xml package.
3463
3464webbrowser - a platform-independent API to launch a web browser.
3465
3466
Guido van Rossume905e952000-09-05 12:42:46 +00003467Changed Modules
3468---------------
3469
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003470array -- new methods for array objects: count, extend, index, pop, and
3471remove
3472
3473binascii -- new functions b2a_hex and a2b_hex that convert between
3474binary data and its hex representation
3475
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003476calendar -- Many new functions that support features including control
3477over which day of the week is the first day, returning strings instead
3478of printing them. Also new symbolic constants for days of week,
3479e.g. MONDAY, ..., SUNDAY.
3480
3481cgi -- FieldStorage objects have a getvalue method that works like a
3482dictionary's get method and returns the value attribute of the object.
3483
3484ConfigParser -- The parser object has new methods has_option,
3485remove_section, remove_option, set, and write. They allow the module
3486to be used for writing config files as well as reading them.
3487
3488ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003489optionally support the RFC 959 REST command.
3490
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003491gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003492
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003493httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3494the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003495
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003496locale -- implement getdefaultlocale for Win32 and Macintosh
3497
3498marshal -- no longer dumps core when marshaling deeply nested or
3499recursive data structures
3500
3501os -- new functions isatty, seteuid, setegid, setreuid, setregid
3502
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003503os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3504support under Unix.
3505
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003506os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003507
3508os.path -- fix semantics of os.path.commonprefix
3509
3510smtplib -- support for sending very long messages
3511
3512socket -- new function getfqdn()
3513
3514readline -- new functions to read, write and truncate history files.
3515The readline section of the library reference manual contains an
3516example.
3517
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003518select -- add interface to poll system call
3519
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003520shutil -- new copyfileobj function
3521
3522SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3523HTTP server.
3524
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003525Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003526
3527urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003528e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003529
3530whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003531
3532
3533Obsolete Modules
3534----------------
3535
3536None. However note that 1.6 made a whole slew of modules obsolete:
3537stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3538poly, zmod, strop, util, whatsound.
3539
3540
3541Changed, New, Obsolete Tools
3542----------------------------
3543
Tim Peters8b092332000-09-05 20:15:25 +00003544None.
Guido van Rossume905e952000-09-05 12:42:46 +00003545
3546
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003547C-level Changes
3548---------------
3549
3550Several cleanup jobs were carried out throughout the source code.
3551
3552All C code was converted to ANSI C; we got rid of all uses of the
3553Py_PROTO() macro, which makes the header files a lot more readable.
3554
3555Most of the portability hacks were moved to a new header file,
3556pyport.h; several other new header files were added and some old
3557header files were removed, in an attempt to create a more rational set
3558of header files. (Few of these ever need to be included explicitly;
3559they are all included by Python.h.)
3560
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003561Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003562and Win64, especially for the new Intel Itanium processor. Mick also
3563added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003564
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003565The C APIs to return an object's size have been update to consistently
3566use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3567previous versions, the abstract interfaces used PyXXX_Length and the
3568concrete interfaces used PyXXX_Size. The old names,
3569e.g. PyObject_Length, are still available for backwards compatibility
3570at the API level, but are deprecated.
3571
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003572The PyOS_CheckStack function has been implemented on Windows by
3573Fredrik Lundh. It prevents Python from failing with a stack overflow
3574on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003575
3576The GC changes resulted in creation of two new slots on object,
3577tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003578the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003579
3580The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003581C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003582
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003583PyErr_Format has been updated to automatically calculate the size of
3584the buffer needed to hold the formatted result string. This change
3585prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003586
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003587New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003588
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003589PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3590that are the same as their non-Ex counterparts except they take an
3591extra flag argument that tells them to close the file when done.
3592
3593XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003594
Tim Peters8b092332000-09-05 20:15:25 +00003595
3596Windows Changes
3597---------------
3598
3599New popen2/popen3/peopen4 in os module (see Changed Modules above).
3600
3601os.popen is much more usable on Windows 95 and 98. See Microsoft
3602Knowledge Base article Q150956. The Win9x workaround described there
3603is implemented by the new w9xpopen.exe helper in the root of your
3604Python installation. Note that Python uses this internally; it is not
3605a standalone program.
3606
3607Administrator privileges are no longer required to install Python
3608on Windows NT or Windows 2000. If you have administrator privileges,
3609Python's registry info will be written under HKEY_LOCAL_MACHINE.
3610Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003611under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003612uses of Python, but will prevent some advanced uses from working
3613(for example, running a Python script as an NT service, or possibly
3614from CGI).
3615
3616[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3617installer; instead, it installs the needed Tcl/Tk files directly in the
3618Python directory. If you already have a Tcl/Tk installation, this
3619wastes some disk space (about 4 Megs) but avoids problems with
3620conflicting Tcl/Tk installations, and makes it much easier for Python
3621to ensure that Tcl/Tk can find all its files.
3622
3623[This was new in 1.6] The Windows installer now installs by default in
3624\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3625
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003626
3627Updates to the changes between 1.5.2 and 1.6
3628--------------------------------------------
3629
3630The 1.6 NEWS file can't be changed after the release is done, so here
3631is some late-breaking news:
3632
3633New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3634and changes to getlocale() and setlocale().
3635
3636The new module is now enabled per default.
3637
3638It is not true that the encodings codecs cannot be used for normal
3639strings: the string.encode() (which is also present on 8-bit strings
3640!) allows using them for 8-bit strings too, e.g. to convert files from
3641cp1252 (Windows) to latin-1 or vice-versa.
3642
3643Japanese codecs are available from Tamito KAJIYAMA:
3644http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3645
3646
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003647======================================================================