blob: df0f8a317807525312eb121007a24bddafc16456 [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Guido van Rossumde392d32002-08-05 14:17:20 +00009- Encoding declarations (PEP 263, phase 1) have been implemented. A
10 comment of the form "# -*- coding: <encodingname> -*-" in the first
11 or second line of a Python source file indicates the encoding.
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +000012
Tim Petersf47630f2002-08-01 02:34:51 +000013- list.sort() has a new implementation. While cross-platform results
14 may vary, and in data-dependent ways, this is much faster on many
15 kinds of partially ordered lists than the previous implementation,
16 and reported to be just as fast on randomly ordered lists on
17 several major platforms. This sort is also stable (if A==B and A
18 precedes B in the list at the start, A precedes B after the sort too),
19 although the language definition does not guarantee stability. A
20 potential drawback is that list.sort() may require temp space of
21 len(list)*2 bytes (*4 on a 64-bit machine). It's therefore possible
22 for list.sort() to raise MemoryError now, even if a comparison function
23 does not. See <http://www.python.org/sf/587076> for full details.
24
Guido van Rossum2d5389c2002-07-23 03:44:35 +000025- All standard iterators now ensure that, once StopIteration has been
26 raised, all future calls to next() on the same iterator will also
27 raise StopIteration. There used to be various counterexamples to
28 this behavior, which could caused confusion or subtle program
29 breakage, without any benefits. (Note that this is still an
30 iterator's responsibility; the iterator framework does not enforce
31 this.)
32
Mark Hammondc0e35152002-07-16 01:32:30 +000033- Ctrl+C handling on Windows has been made more consistent with
34 other platforms. KeyboardInterrupt can now reliably be caught,
Tim Petersf47630f2002-08-01 02:34:51 +000035 and Ctrl+C at an interative prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +000036 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Petersf47630f2002-08-01 02:34:51 +000037 interrupt time.sleep() in the main thread, and any child processes
38 created via the popen family are also interrupted (as generally
Mark Hammondc0e35152002-07-16 01:32:30 +000039 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
40
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000041- Slices and repetitions of buffer objects now consistently return
42 a string. Formerly, strings would be returned most of the time,
43 but a buffer object would be returned when the repetition count
44 was one or when the slice range was all inclusive.
45
Guido van Rossumc7c36502002-06-21 01:29:25 +000046- The __slots__ variable can now mention "private" names, and the
47 right thing will happen (e.g. __slots__ = ["__foo"]).
48
Walter Dörwald3430d702002-06-17 10:43:59 +000049- Unicode objects in sys.path are no longer ignored but treated
50 as directory names.
51
Guido van Rossum9562bcf2002-06-14 21:31:18 +000052- The built-ins slice() and buffer() are now callable types. The
53 types classobj (formerly class), code, function, instance, and
54 instancemethod (formerly instance-method), which have no built-in
55 names but are accessible through the types module, are now also
56 callable. The type dict-proxy is renamed to dictproxy.
57
Neal Norwitz1f68fc72002-06-14 00:50:42 +000058- Fixed string.startswith and string.endswith builtin methods
59 so they accept negative indices. [SF bug 493951]
60
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000061- Fixed a bug with a continue inside a try block and a yield in the
62 finally clause. [SF bug 567538]
63
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000064- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000065 with a third "stride" parameter. For example, "hello world"[::-1]
66 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000067
Guido van Rossum9f7549b2002-06-10 21:39:42 +000068- Cycles going through the __class__ link of a new-style instance are
69 now detected by the garbage collector.
70
Guido van Rossum9923ffe2002-06-04 19:52:53 +000071- Classes using __slots__ are now properly garbage collected.
72 [SF bug 519621]
73
74- Tightened the __slots__ rules: a slot name must be a valid Python
75 identifier.
76
Guido van Rossum2e4e0262002-06-04 05:58:34 +000077- The constructor for the module type now requires a name argument and
78 takes an optional docstring argument. Previously, this constructor
79 ignored its arguments. As a consequence, deriving a class from a
80 module (not from the module type) is now illegal; previously this
81 created an unnamed module, just like invoking the module type did.
82 [SF bug 563060]
83
Neal Norwitzd68f5172002-05-29 15:54:55 +000084- A new warning PendingDeprecationWarning was added to provide
85 direction on features which are in the process of being deprecated.
86 The warning will not be printed by default. To see the pending
87 deprecations, use -Walways::PendingDeprecationWarning::
88 as a command line option or warnings.filterwarnings() in code.
89
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000090- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000091 for 'str' and 'unicode', and can be used instead of
92 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000093 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000094 is an abstract base class and cannot be instantiated directly.
95
Fred Draked0ba6362002-05-02 21:28:26 +000096- Deprecated features of xrange objects have been removed as
97 promised. The start, stop, and step attributes and the tolist()
98 method no longer exist. xrange repetition and slicing have been
99 removed.
100
Guido van Rossum7dab2422002-04-26 19:40:56 +0000101- New builtin function enumerate(x), from PEP 279. Example:
102 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
103 The argument can be an arbitrary iterable object.
104
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000105- The assert statement no longer tests __debug__ at runtime. This means
106 that assert statements cannot be disabled by assigning a false value
107 to __debug__.
108
Walter Dörwald068325e2002-04-15 13:36:47 +0000109- A method zfill() was added to str and unicode, that fills a numeric
110 string to the left with zeros. For example,
111 "+123".zfill(6) -> "+00123".
112
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000113- Complex numbers supported divmod() and the // and % operators, but
114 these make no sense. Since this was documented, they're being
115 deprecated now.
116
Guido van Rossum26dd8302002-04-26 20:11:29 +0000117- String and unicode methods lstrip(), rstrip() and strip() now take
118 an optional argument that specifies the characters to strip. For
119 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000120
Guido van Rossumc69343b2002-04-12 19:22:48 +0000121- Added a new dict method pop(key). This removes and returns the
122 value corresponding to key. [SF patch #539949]
123
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000124- Changed new-style class instantiation so that when C's __new__
125 method returns something that's not a C instance, its __init__ is
126 not called. [SF bug #537450]
127
Guido van Rossum181e41a2002-04-06 00:23:25 +0000128- Fixed super() to work correctly with class methods. [SF bug #535444]
129
Guido van Rossum47834462002-04-04 15:21:33 +0000130- A new built-in type, bool, has been added, as well as built-in
131 names for its two values, True and False. Comparisons and sundry
132 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000133 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000134 is backward compatible.
135
Guido van Rossum95b62a62002-03-29 01:07:24 +0000136- Fixed two bugs reported as SF #535905: under certain conditions,
137 deallocating a deeply nested structure could cause a segfault in the
138 garbage collector, due to interaction with the "trashcan" code;
139 access to the current frame during destruction of a local variable
140 could access a pointer to freed memory.
141
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000142- The optional object allocator ("pymalloc") has been enabled by
143 default. The recommended practice for memory allocation and
144 deallocation has been streamlined. A header file is included,
145 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
146 and lets them use the same API with Python versions from 1.5.2
147 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000148
Guido van Rossum8c842552002-03-14 23:05:54 +0000149- If you try to pickle an instance of a class that has __slots__ but
150 doesn't define or override __getstate__, a TypeError is now raised.
151 This is done by adding a bozo __getstate__ to the class that always
152 raises TypeError. (Before, this would appear to be pickled, but the
153 state of the slots would be lost.)
154
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000155- PyErr_Display will provide file and line information for all exceptions
156 that have an attribute print_file_and_line, not just SyntaxErrors.
157
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000158- The UTF-8 codec will now encode and decode Unicode surrogates
159 correctly and without raising exceptions for unpaired ones.
160
Neal Norwitz649b7592002-01-01 19:07:13 +0000161- file.xreadlines() now raises a ValueError if the file is closed:
162 Previously, an xreadlines object was returned which would raise
163 a ValueError when the xreadlines.next() method was called.
164
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000165- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000166 An exception will now be raised if more than one argument is used.
167
Tim Petersaf8446f2001-12-21 21:36:50 +0000168Extension modules
169
Guido van Rossum79f0a102002-07-23 03:32:08 +0000170- The strptime function in the time module is now always available (a
171 Python implementation is used when the C library doesn't define it).
172
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000173- The 'new' module is no longer an extension, but a Python module that
174 only exists for backwards compatibility. Its contents are no longer
175 functions but callable type objects.
176
Tim Peters81b92512002-04-29 01:37:32 +0000177- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000178 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000179 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000180
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000181- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
182 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000183
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000184- The locale module now exposes the C library's gettext interface.
185
Tim Petersfbf74f22002-03-14 19:06:01 +0000186- A security hole ("double free") was found in zlib-1.1.3, a popular
187 third party compression library used by some Python modules. The
188 hole was quickly plugged in zlib-1.1.4, and the Windows build of
189 Python now ships with zlib-1.1.4.
190
Martin v. Löwis688357e2002-04-08 21:28:20 +0000191- pwd, grp, and resource return enhanced tuples now, with symbolic
192 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000193
Martin v. Löwis99866332002-03-01 10:27:01 +0000194- array.array is now a type object. A new format character
195 'u' indicates Py_UNICODE arrays. For those, .tounicode and
196 .fromunicode methods are available. Arrays now support __iadd__
197 and __imul__.
198
Neal Norwitze790eae2002-01-01 21:14:12 +0000199- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000200 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
201 is called.
202
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000203- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
204 been added where available.
205
Tim Petersaf8446f2001-12-21 21:36:50 +0000206Library
207
Guido van Rossum4a57c332002-08-02 18:05:20 +0000208- New "algorithms" module: heapq, implements a heap queue. Thanks to
209 Kevin O'Connor for the code and François Pinard for an entertaining
210 write-up explaining the theory and practical uses of heaps.
211
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000212- New encoding for the Palm OS character set: palmos.
213
Tim Peters943382c2002-07-07 03:59:34 +0000214- binascii.crc32() and the zipfile module had problems on some 64-bit
215 platforms. These have been fixed. On a platform with 8-byte C longs,
216 crc32() now returns a signed-extended 4-byte result, so that its value
217 as a Python int is equal to the value computed a 32-bit platform.
218
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000219- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
220 argument.
221
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000222- Some fixes in the copy module: when an object is copied through its
223 __reduce__ method, there was no check for a __setstate__ method on
224 the result [SF patch 565085]; deepcopy should treat instances of
225 custom metaclasses the same way it treats instances of type 'type'
226 [SF patch 560794].
227
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000228- Sockets now support timeout mode. After s.settimeout(T), where T is
229 a float expressing seconds, subsequent operations raise an exception
230 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000231 mode, use s.settimeout(None). There's also a module function,
232 socket.setdefaulttimeout(T), which sets the default for all sockets
233 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000234
235- getopt.gnu_getopt was added. This supports GNU-style option
236 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000237
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000238- Stop using strings for exceptions. String objects used for
239 exceptions are now classes deriving from Exception. The objects
240 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
241 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000242
Walter Dörwald474458d2002-06-04 15:16:29 +0000243- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
244 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
245 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
246 big endian systems were added to the codecs module. The old names
247 BOM32_* and BOM64_* were off by a factor of 2.
248
Guido van Rossumf9257822002-06-18 20:43:18 +0000249- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000250
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000251- ftplib.retrlines() now tests for callback is None rather than testing
252 for False. Was causing an error when given a callback object which
253 was callable but also returned len() as zero. The change may
254 create new breakage if the caller relied on the undocumented behavior
255 and called with callback set to [] or some other False value not
256 identical to None.
257
Tim Peters46c04e12002-05-05 20:40:00 +0000258- random.gauss() uses a piece of hidden state used by nothing else,
259 and the .seed() and .whseed() methods failed to reset it. In other
260 words, setting the seed didn't completely determine the sequence of
261 results produced by random.gauss(). It does now. Programs repeatedly
262 mixing calls to a seed method with calls to gauss() may see different
263 results now.
264
Fred Drake7f781c92002-05-01 20:33:53 +0000265- The pickle.Pickler class grew a clear_memo() method to mimic that
266 provided by cPickle.Pickler.
267
Tim Peters81b92512002-04-29 01:37:32 +0000268- difflib's SequenceMatcher class now does a dynamic analysis of
269 which elements are so frequent as to constitute noise. For
270 comparing files as sequences of lines, this generally works better
271 than the IS_LINE_JUNK function, and function ndiff's linejunk
272 argument defaults to None now as a result. A happy benefit is
273 that SequenceMatcher may run much faster now when applied
274 to large files with many duplicate lines (for example, C program
275 text with lots of repeated "}" and "return NULL;" lines).
276
Guido van Rossum256705b2002-04-23 13:29:43 +0000277- New Text.dump() method in Tkinter module.
278
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000279- New distutils commands for building packagers were added to
280 support pkgtool on Solaris and swinstall on HP-UX.
281
282- distutils now has a new abstract binary packager base class
283 command/bdist_packager, which simplifies writing packagers.
284 This will hopefully provide the missing bits to encourage
285 people to submit more packagers, e.g. for Debian, FreeBSD
286 and other systems.
287
Guido van Rossumf9257822002-06-18 20:43:18 +0000288- The UTF-16, -LE and -BE stream readers now raise a
289 NotImplementedError for all calls to .readline(). Previously, they
290 used to just produce garbage or fail with an encoding error --
291 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 +0000292 work well with these.
293
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000294- compileall now supports quiet operation.
295
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000296- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000297 connections.
298
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000299- socket module: the SSL support was broken out of the main
300 _socket module C helper and placed into a new _ssl helper
301 which now gets imported by socket.py if available and working.
302
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000303- encodings package: added aliases for all supported IANA character
304 sets
305
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000306- ftplib: to safeguard the user's privacy, anonymous login will use
307 "anonymous@" as default password, rather than the real user and host
308 name.
309
Fred Drake36736122002-01-10 13:50:31 +0000310- webbrowser: tightened up the command passed to os.system() so that
311 arbitrary shell code can't be executed because a bogus URL was
312 passed in.
313
Tim Peters11bd9942002-02-01 00:52:29 +0000314- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000315 gettext.find an optional all argument. Translations will now fallback
316 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000317
Martin v. Löwis9668b932002-01-12 11:27:42 +0000318- distutils bdist commands now offer a --skip-build option.
319
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000320- warnings.warn now accepts a Warning instance as first argument.
321
Fred Drakefed7e852002-04-04 19:36:15 +0000322- The xml.sax.expatreader.ExpatParser class will no longer create
323 circular references by using itself as the locator that gets passed
324 to the content handler implementation. [SF bug #535474]
325
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000326- The email.Parser.Parser class now properly parses strings regardless
327 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
328 or CRLF). Also, the Header class's constructor default arguments
329 has changed slightly so that an explicit maxlinelen value is always
330 honored.
331
Tim Petersaf8446f2001-12-21 21:36:50 +0000332Tools/Demos
333
Marc-André Lemburg46260092002-04-04 16:17:11 +0000334- freeze.py now produces binaries which can import shared modules,
335 unlike before when this failed due to missing symbol exports in
336 the generated binary.
337
Tim Petersaf8446f2001-12-21 21:36:50 +0000338Build
339
Tim Petersf47630f2002-08-01 02:34:51 +0000340- The public Python C API will generally be declared using PyAPI_FUNC
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000341 and PyAPI_DATA macros, while Python extension module init functions
342 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
343 are deprecated.
344
Tim Petersc6a3ff62002-07-08 22:11:52 +0000345- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
346 get into infinite loops, when a new-style class got garbage-collected.
347 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
348 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
349 COUNT_ALLOCS is not enabled by default, in either release or debug
350 builds, and that new-style classes are immortal only in COUNT_ALLOCS
351 builds.
352
Tim Peters943382c2002-07-07 03:59:34 +0000353- Compiling out the cyclic garbage collector is no longer an option.
354 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
355 that it's always defined (for the benefit of any extension modules
356 that may be conditionalizing on it). A bonus is that any extension
357 type participating in cyclic gc can choose to participate in the
358 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
359 to require editing the core to teach the trashcan mechanism about the
360 new type.
361
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000362- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000363
364 The Standard C macro HUGE_VAL and its float and long double analogs,
365 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
366 positive infinities.
367
368 Python only uses the double HUGE_VAL, and only to #define its own symbol
369 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
370 pyport.h used to try to worm around that, but the workarounds triggered
371 other bugs on other platforms, so we gave up. If your platform defines
372 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
373 that works on your platform. The only instance of this I'm sure about
374 is on an unknown subset of Cray systems, described here:
375
376 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
377
378 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
379
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000380- The configure option --without-doc-strings can be used to remove the
381 doc strings from the builtin functions and modules; this reduces the
382 size of the executable.
383
Tim Peters639295f2002-04-21 07:30:30 +0000384- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
385 say how or when to configure it, or how to turn it off.
386
Martin v. Löwis1142de32002-03-29 16:28:31 +0000387- On Unix, a shared libpython2.3.so can be created with --enable-shared.
388
Tim Peters8deda702002-03-30 10:06:07 +0000389- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
390 preprocessor symbols were eliminated. The internal decisions they
391 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000392
Fred Drake7d28b732002-05-02 21:17:00 +0000393- The tools used to build the documentation now work under Cygwin as
394 well as Unix.
395
Skip Montanaro57454e52002-06-14 20:30:31 +0000396- The bsddb and dbm module builds have been changed to try and avoid version
397 skew problems and disable linkage with Berkeley DB 1.85 unless the
398 installer knows what s/he's doing. See the section on building these
399 modules in the README file for details.
400
Tim Petersaf8446f2001-12-21 21:36:50 +0000401C API
402
Thomas Heller085358a2002-07-29 14:27:41 +0000403- New functions PyErr_SetExcFromWindowsErr() and
404 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
405 PyErr_SetFromWindowsErrWithFilename() and
406 PyErr_SetFromWindowsErr(), but they allow to specify
407 the exception type to raise. Available on Windows.
408
Tim Peters7c321a82002-07-09 02:57:01 +0000409- Py_FatalError() is now declared as taking a const char* argument. It
410 was previously declared without const. This should not affect working
411 code.
412
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000413- Added new macro PySequence_ITEM(o, i) that directly calls
414 sq_item without rechecking that o is a sequence and without
415 adjusting for negative indices.
416
Fred Draked0ba6362002-05-02 21:28:26 +0000417- PyRange_New() now raises ValueError if the fourth argument is not 1.
418 This is part of the removal of deprecated features of the xrange
419 object.
420
Guido van Rossum517c7d42002-04-26 02:49:14 +0000421- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
422 coercion if both arguments have the same type but this type has the
423 CHECKTYPES flag set. This is to better support proxies.
424
Neil Schemenauer9344b142002-04-12 23:00:08 +0000425- The type of tp_free has been changed from "void (*)(PyObject *)" to
426 "void (*)(void *)".
427
428- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
429
Guido van Rossum0986d822002-04-08 01:38:42 +0000430- A type can now inherit its metatype from its base type. Previously,
431 when PyType_Ready() was called, if ob_type was found to be NULL, it
432 was always set to &PyType_Type; now it is set to base->ob_type,
433 where base is tp_base, defaulting to &PyObject_Type.
434
435- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
436
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000437- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000438
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000439- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000440 without going through the buffer API.
441
Martin v. Löwis7198a522002-01-01 19:59:11 +0000442- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
443
Tim Peters10a3bb52001-12-25 19:07:38 +0000444- An old #define of ANY as void has been removed from pyport.h. This
445 hasn't been used since Python's pre-ANSI days, and the #define has
446 been marked as obsolete since then. SF bug 495548 says it created
447 conflicts with other packages, so keeping it around wasn't harmless.
448
Tim Petersaf8446f2001-12-21 21:36:50 +0000449- Because Python's magic number scheme broke on January 1st, we decided
450 to stop Python development. Thanks for all the fish!
451
Tim Petersfb05db22002-03-11 00:24:00 +0000452- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000453 scheme to a new one. See Python/import.c for details.
454
Tim Petersaf8446f2001-12-21 21:36:50 +0000455New platforms
456
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000457- AtheOS is now supported.
458
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000459- the EMX runtime environment on OS/2 is now supported.
460
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000461- GNU/Hurd is now supported.
462
Tim Petersaf8446f2001-12-21 21:36:50 +0000463Tests
464
465Windows
466
Tim Peters08e72952002-04-16 20:48:01 +0000467- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
468 of that has been fixed in the installer (disabled Wise's "delete in-
469 use files" uninstall option).
470
Guido van Rossum181e41a2002-04-06 00:23:25 +0000471- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
472
Tim Peters33187922002-04-04 20:02:04 +0000473- The installer now installs Start menu shortcuts under (the local
474 equivalent of) "All Users" when doing an Admin install.
475
Tim Petersfb05db22002-03-11 00:24:00 +0000476- file.truncate([newsize]) now works on Windows for all newsize values.
477 It used to fail if newsize didn't fit in 32 bits, reflecting a
478 limitation of MS _chsize (which is no longer used).
479
Tim Petersab034fa2002-02-01 11:27:43 +0000480- os.waitpid() is now implemented for Windows, and can be used to block
481 until a specified process exits. This is similar to, but not exactly
482 the same as, os.waitpid() on POSIX systems. If you're waiting for
483 a specific process whose pid was obtained from one of the spawn()
484 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000485 See the docs for details. The docs were changed to clarify that
486 spawn functions return, and waitpid requires, a process handle on
487 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000488
Tim Peters11bd9942002-02-01 00:52:29 +0000489- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000490 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000491 to a nasty problem: before 2.3, if you got a temp file on Windows, it
492 got wrapped in an object whose close() method first closed the
493 underlying file, then deleted the file. This usually worked fine.
494 However, the spawn family of functions on Windows create (at a low C
495 level) the same set of open files in the spawned process Q as were
496 open in the spawning process P. If a temp file f was among them, then
497 doing f.close() in P first closed P's C-level file handle on f, but Q's
498 C-level file handle on f remained open, so the attempt in P to delete f
499 blew up with a "Permission denied" error (Windows doesn't allow
500 deleting open files). This was surprising, subtle, and difficult to
501 work around.
502
503- The os module now exports all the symbolic constants usable with the
504 low-level os.open() on Windows: the new constants in 2.3 are
505 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
506 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
507 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
508 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
509 (so specify both if you want both; note that neither is useful unless
510 specified with O_CREAT too).
511
Tim Petersaf8446f2001-12-21 21:36:50 +0000512Mac
513
514
Tim Peters909c0912001-12-14 23:16:18 +0000515What's New in Python 2.2 final?
516Release date: 21-Dec-2001
517===============================
518
519Type/class unification and new-style classes
520
Barry Warsaw52acb492001-12-21 20:04:22 +0000521- pickle.py, cPickle: allow pickling instances of new-style classes
522 with a custom metaclass.
523
Tim Peters909c0912001-12-14 23:16:18 +0000524Core and builtins
525
Barry Warsaw52acb492001-12-21 20:04:22 +0000526- weakref proxy object: when comparing, unwrap both arguments if both
527 are proxies.
528
Tim Peters909c0912001-12-14 23:16:18 +0000529Extension modules
530
Barry Warsaw52acb492001-12-21 20:04:22 +0000531- binascii.b2a_base64(): fix a potential buffer overrun when encoding
532 very short strings.
533
534- cPickle: the obscure "fast" mode was suspected of causing stack
535 overflows on the Mac. Hopefully fixed this by setting the recursion
536 limit much smaller. If the limit is too low (it only affects
537 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
538 when compiling cPickle.c (or in pyconfig.h).
539
Tim Peters909c0912001-12-14 23:16:18 +0000540Library
541
Barry Warsaw52acb492001-12-21 20:04:22 +0000542- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
543 close or delete time).
544
545- rfc822.py: fixed a bug where the address '<>' was converted to None
546 instead of an empty string (also fixes the email.Utils module).
547
548- xmlrpclib.py: version 1.0.0; uses precision for doubles.
549
550- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000551 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000552
Tim Peters909c0912001-12-14 23:16:18 +0000553Tools/Demos
554
555Build
556
557C API
558
559New platforms
560
561Tests
562
563Windows
564
Barry Warsaw52acb492001-12-21 20:04:22 +0000565- distutils package: fixed broken Windows installers (bdist_wininst).
566
567- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
568 instances are deleted at process exit time.
569
570- socket.py: prevent mysterious warnings when socket instances are
571 deleted at process exit time.
572
573- posixmodule.c: fix a Windows crash with stat() of a filename ending
574 in backslash.
575
Tim Peters909c0912001-12-14 23:16:18 +0000576Mac
577
Barry Warsaw52acb492001-12-21 20:04:22 +0000578- The Carbon toolbox modules have been upgraded to Universal Headers
579 3.4, and experimental CoreGraphics and CarbonEvents modules have
580 been added. All only for framework-enabled MacOSX.
581
Tim Peters909c0912001-12-14 23:16:18 +0000582
Tim Peters6272dfd2001-12-13 19:34:00 +0000583What's New in Python 2.2c1?
584Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000585===========================
586
587Type/class unification and new-style classes
588
Barry Warsaw06557452001-12-14 20:47:12 +0000589- Guido's tutorial introduction to the new type/class features has
590 been extensively updated. See
591
592 http://www.python.org/2.2/descrintro.html
593
594 That remains the primary documentation in this area.
595
Guido van Rossum33bab012001-12-05 22:45:48 +0000596- Fixed a leak: instance variables declared with __slots__ were never
597 deleted!
598
Guido van Rossum4b800852001-12-03 00:54:52 +0000599- The "delete attribute" method of descriptor objects is called
600 __delete__, not __del__. In previous releases, it was mistakenly
601 called __del__, which created an unfortunate overloading condition
602 with finalizers. (The "get attribute" and "set attribute" methods
603 are still called __get__ and __set__, respectively.)
604
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000605- Some subtle issues with the super built-in were fixed:
606
607 (a) When super itself is subclassed, its __get__ method would still
608 return an instance of the base class (i.e., of super).
609
610 (b) super(C, C()).__class__ would return C rather than super. This
611 is confusing. To fix this, I decided to change the semantics of
612 super so that it only applies to code attributes, not to data
613 attributes. After all, overriding data attributes is not
614 supported anyway.
615
616 (c) The __get__ method didn't check whether the argument was an
617 instance of the type used in creation of the super instance.
618
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000619- Previously, hash() of an instance of a subclass of a mutable type
620 (list or dictionary) would return some value, rather than raising
621 TypeError. This has been fixed. Also, directly calling
622 dict.__hash__ and list.__hash__ now raises the same TypeError
623 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000624
Guido van Rossumd331cb52001-12-05 19:46:42 +0000625- New-style objects now support deleting their __dict__. This is for
626 all intents and purposes equivalent to assigning a brand new empty
627 dictionary, but saves space if the object is not used further.
628
Tim Petersb3c9af12001-11-17 00:21:57 +0000629Core and builtins
630
Tim Peters3caca232001-12-06 06:23:26 +0000631- -Qnew now works as documented in PEP 238: when -Qnew is passed on
632 the command line, all occurrences of "/" use true division instead
633 of classic division. See the PEP for details. Note that "all"
634 means all instances in library and 3rd-party modules, as well as in
635 your own code. As the PEP says, -Qnew is intended for use only in
636 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000637 Note that test_coercion.py in the standard Python test suite fails
638 under -Qnew; this is expected, and won't be repaired until true
639 division becomes the default (in the meantime, test_coercion is
640 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000641
Fred Drake6c01e252001-12-14 17:08:12 +0000642- complex() now only allows the first argument to be a string
643 argument, and raises TypeError if either the second arg is a string
644 or if the second arg is specified when the first is a string.
645
Tim Petersb3c9af12001-11-17 00:21:57 +0000646Extension modules
647
Martin v. Löwis560da622001-11-24 09:24:51 +0000648- gc.get_referents was renamed to gc.get_referrers.
649
Tim Petersb3c9af12001-11-17 00:21:57 +0000650Library
651
Tim Peters25059d32001-12-07 20:35:43 +0000652- Functions in the os.spawn() family now release the global interpreter
653 lock around calling the platform spawn. They should always have done
654 this, but did not before 2.2c1. Multithreaded programs calling
655 an os.spawn function with P_WAIT will no longer block all Python threads
656 until the spawned program completes. It's possible that some programs
657 relies on blocking, although more likely by accident than by design.
658
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000659- webbrowser defaults to netscape.exe on OS/2 now.
660
Martin v. Löwis652e1912001-11-25 14:50:56 +0000661- Tix.ResizeHandle exposes detach_widget, hide, and show.
662
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000663- The charset alias windows_1252 has been added.
664
Barry Warsaw06557452001-12-14 20:47:12 +0000665- types.StringTypes is a tuple containing the defined string types;
666 usually this will be (str, unicode), but if Python was compiled
667 without Unicode support it will be just (str,).
668
669- The pulldom and minidom modules were synchronized to PyXML.
670
Tim Petersb3c9af12001-11-17 00:21:57 +0000671Tools/Demos
672
Barry Warsaw06557452001-12-14 20:47:12 +0000673- A new script called Tools/scripts/google.py was added, which fires
674 off a search on Google.
675
Tim Petersb3c9af12001-11-17 00:21:57 +0000676Build
677
Barry Warsaw06557452001-12-14 20:47:12 +0000678- Note that release builds of Python should arrange to define the
679 preprocessor symbol NDEBUG on the command line (or equivalent).
680 In the 2.2 pre-release series we tried to define this by magic in
681 Python.h instead, but it proved to cause problems for extension
682 authors. The Unix, Windows and Mac builds now all define NDEBUG in
683 release builds via cmdline (or equivalent) instead. Ports to
684 other platforms should do likewise.
685
Jack Jansen1999ef42001-12-06 21:47:20 +0000686- It is no longer necessary to use --with-suffix when building on a
687 case-insensitive file system (such as Mac OS X HFS+). In the build
688 directory an extension is used, but not in the installed python.
689
Tim Petersb3c9af12001-11-17 00:21:57 +0000690C API
691
Tim Petersf582b822001-12-11 18:51:08 +0000692- New function PyDict_MergeFromSeq2() exposes the builtin dict
693 constructor's logic for updating a dictionary from an iterable object
694 producing key-value pairs.
695
Tim Peterscffed4b2001-11-29 03:26:37 +0000696- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000697 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000698 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
699 dump core in some bad cases. This has been repaired. As a result,
700 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
701 previously went unchallenged.
702
Tim Petersb3c9af12001-11-17 00:21:57 +0000703New platforms
704
705Tests
706
707Windows
708
709Mac
710
Jack Jansenffa260f2001-12-06 21:14:00 +0000711- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
712 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000713
Barry Warsaw06557452001-12-14 20:47:12 +0000714- Changed logic for finding python home in Mac OS X framework Pythons.
715 Now sys.executable points to the executable again, in stead of to
716 the shared library. The latter is used only for locating the python
717 home.
718
719
Tim Peters84362bc2001-10-19 17:55:30 +0000720What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000721Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000722===========================
723
724Type/class unification and new-style classes
725
Guido van Rossum3d27df02001-11-15 20:27:54 +0000726- Multiple inheritance mixing new-style and classic classes in the
727 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000728
729 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000730 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000731
732 The MRO (method resolution order) for each base class is respected
733 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000734 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000735 This needs to be documented.
736
Tim Petersa427a2b2001-10-29 22:25:45 +0000737- The new builtin dictionary() constructor, and dictionary type, have
738 been renamed to dict. This reflects a decade of common usage.
739
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000740- dict() now accepts an iterable object producing 2-sequences. For
741 example, dict(d.items()) == d for any dictionary d. The argument,
742 and the elements of the argument, can be any iterable objects.
743
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000744- New-style classes can now have a __del__ method, which is called
745 when the instance is deleted (just like for classic classes).
746
Guido van Rossum12d955c2001-10-26 14:56:06 +0000747- Assignment to object.__dict__ is now possible, for objects that are
748 instances of new-style classes that have a __dict__ (unless the base
749 class forbids it).
750
Guido van Rossumc8e56452001-10-22 00:43:43 +0000751- Methods of built-in types now properly check for keyword arguments
752 (formerly these were silently ignored). The only built-in methods
753 that take keyword arguments are __call__, __init__ and __new__.
754
Guido van Rossum86443212001-10-27 22:28:54 +0000755- The socket function has been converted to a type; see below.
756
Tim Peters84362bc2001-10-19 17:55:30 +0000757Core and builtins
758
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000759- Assignment to __debug__ raises SyntaxError at compile-time. This
760 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000761 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000762
Guido van Rossum12d955c2001-10-26 14:56:06 +0000763- Clarified the error messages for unsupported operands to an operator
764 (like 1 + '').
765
Tim Peters84362bc2001-10-19 17:55:30 +0000766Extension modules
767
Tim Peters5ebfd362001-11-13 23:11:19 +0000768- mmap has a new keyword argument, "access", allowing a uniform way for
769 both Windows and Unix users to create read-only, write-through and
770 copy-on-write memory mappings. This was previously possible only on
771 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000772 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000773 platforms. Thanks to Jay T Miller for repairing this!
774
Tim Peters169ded02001-11-03 19:57:21 +0000775- By default, the gc.garbage list now contains only those instances in
776 unreachable cycles that have __del__ methods; in 2.1 it contained all
777 instances in unreachable cycles. "Instances" here has been generalized
778 to include instances of both new-style and old-style classes.
779
Guido van Rossum12d955c2001-10-26 14:56:06 +0000780- The socket module defines a new method for socket objects,
781 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000782 send() until all data has been sent. Also, the socket function has
783 been converted to a subclassable type, like list and tuple (etc.)
784 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000785
786- Various bugfixes to the curses module. There is now a test suite
787 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000788
Guido van Rossum692adf12001-10-30 03:03:03 +0000789- binascii.b2a_base64 no longer places an arbitrary restriction of 57
790 bytes on its input.
791
Tim Peters84362bc2001-10-19 17:55:30 +0000792Library
793
Tim Peters5ebfd362001-11-13 23:11:19 +0000794- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000795 convenience function.
796
Tim Peters75335872001-11-03 19:35:43 +0000797- Symbolic group names in regular expressions must be unique. For
798 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
799 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000800 Python 2.2 detects this error at regexp compilation time;
801 previously, the error went undetected, and results were
802 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
803 pattern.subn() methods have been rewritten in C. Also, an
804 experimental function/method finditer() has been added, which works
805 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000806
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000807- Tix exposes more commands through the classes DirSelectBox,
808 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
809 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
810 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
811
Tim Peters98791af2001-10-23 01:59:54 +0000812- Traceback objects are now scanned by cyclic garbage collection, so
813 cycles created by casual use of sys.exc_info() no longer cause
814 permanent memory leaks (provided garbage collection is enabled).
815
Guido van Rossum49192142001-10-24 20:51:44 +0000816- os.extsep -- a new variable needed by the RISCOS support. It is the
817 separator used by extensions, and is '.' on all platforms except
818 RISCOS, where it is '/'. There is no need to use this variable
819 unless you have a masochistic desire to port your code to RISCOS.
820
Barry Warsaw012852b2001-11-16 16:17:27 +0000821- mimetypes.py has optional support for non-standard, but commonly
822 found types. guess_type() and guess_extension() now accept an
823 optional `strict' flag, defaulting to true, which controls whether
824 recognize non-standard types or not. A few non-standard types we
825 know about have been added. Also, when run as a script, there are
826 new -l and -e options.
827
828- statcache is now deprecated.
829
830- email.Utils.formatdate() now produces the preferred RFC 2822 style
831 dates with numeric timezones (it used to produce obsolete dates
832 hard coded to "GMT" timezone). An optional `localtime' flag is
833 added to produce dates in the local timezone, with daylight savings
834 time properly taken into account.
835
836- In pickle and cPickle, instead of masking errors in load() by
837 transforming them into SystemError, we let the original exception
838 propagate out. Also, implement support for __safe_for_unpickling__
839 in pickle, as it already was supported in cPickle.
840
Tim Peters84362bc2001-10-19 17:55:30 +0000841Tools/Demos
842
843Build
844
Barry Warsaw012852b2001-11-16 16:17:27 +0000845- The dbm module is built using libdb1 if available. The bsddb module
846 is built with libdb3 if available.
847
848- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
849
Tim Peters84362bc2001-10-19 17:55:30 +0000850C API
851
Tim Peters1fc240e2001-10-26 05:06:50 +0000852- New function PySequence_Fast_GET_SIZE() returns the size of a non-
853 NULL result from PySequence_Fast(), more quickly than calling
854 PySequence_Size().
855
Barry Warsaw012852b2001-11-16 16:17:27 +0000856- New argument unpacking function PyArg_UnpackTuple() added.
857
858- New functions PyObject_CallFunctionObjArgs() and
859 PyObject_CallMethodObjArgs() have been added to make it more
860 convenient and efficient to call functions and methods from C.
861
862- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
863 possible that this will propagate errors it didn't before.
864
865- New function PyObject_CheckReadBuffer(), which returns true if its
866 argument supports the single-segment readable buffer interface.
867
Tim Peters84362bc2001-10-19 17:55:30 +0000868New platforms
869
Guido van Rossum86443212001-10-27 22:28:54 +0000870- We've finally confirmed that this release builds on HP-UX 11.00,
871 *with* threads, and passes the test suite.
872
Tim Peters7a33d8b2001-11-05 02:51:07 +0000873- Thanks to a series of patches from Michael Muller, Python may build
874 again under OS/2 Visual Age C++.
875
Guido van Rossum49192142001-10-24 20:51:44 +0000876- Updated RISCOS port by Dietmar Schwertberger.
877
Tim Peters84362bc2001-10-19 17:55:30 +0000878Tests
879
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000880- Added a test script for the curses module. It isn't run automatically;
881 regrtest.py must be run with '-u curses' to enable it.
882
Tim Peters84362bc2001-10-19 17:55:30 +0000883Windows
884
Barry Warsaw012852b2001-11-16 16:17:27 +0000885Mac
886
887- PythonScript has been moved to unsupported and is slated to be
888 removed completely in the next release.
889
890- It should now be possible to build applets that work on both OS9 and
891 OSX.
892
893- The core is now linked with CoreServices not Carbon; as a side
894 result, default 8bit encoding on OSX is now ASCII.
895
896- Python should now build on OSX 10.1.1
897
Tim Peters84362bc2001-10-19 17:55:30 +0000898
Tim Petersabf925f2001-09-28 21:53:42 +0000899What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000900Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000901===========================
902
903Type/class unification and new-style classes
904
Guido van Rossum687ae002001-10-15 22:03:32 +0000905- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000906 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000907 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000908 remains: the __dict__ of a new-style class is a read-only proxy; you
909 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000910 __defined__ attribute of new-style types no longer exists, for lack
911 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000912 future a __cache__ may be resurrected with a similar function, if I
913 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000914
Tim Peters1c9ca872001-10-04 06:43:12 +0000915- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
916 always returned None, even when there was a class docstring).
917
918- doctest now finds and runs docstrings attached to new-style classes,
919 class methods, static methods, and properties.
920
Guido van Rossum9074ef62001-10-16 21:34:49 +0000921Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000922
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000923- A very subtle syntactical pitfall in list comprehensions was fixed.
924 For example: [a+b for a in 'abc', for b in 'def']. The comma in
925 this example is a mistake. Previously, this would silently let 'a'
926 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
927 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
928 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
929 Note that [a for a in <singleton>] is a convoluted way to say
930 [<singleton>] anyway, so it's not like any expressiveness is lost.
931
Guido van Rossum9074ef62001-10-16 21:34:49 +0000932- getattr(obj, name, default) now only catches AttributeError, as
933 documented, rather than returning the default value for all
934 exceptions (which could mask bugs in a __getattr__ hook, for
935 example).
936
Fred Drakecb7a6b52001-10-22 18:41:51 +0000937- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000938 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000939 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000940 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000941
Guido van Rossum1c486092001-10-19 02:05:35 +0000942- unicode(obj) now behaves more like str(obj), accepting arbitrary
943 objects, and calling a __unicode__ method if it exists.
944 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000945 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000946
Barry Warsawf6fb1712001-10-19 05:35:40 +0000947- isinstance() now allows any object as the first argument and a
948 class, a type or something with a __bases__ tuple attribute for the
949 second argument. The second argument may also be a tuple of a
950 class, type, or something with __bases__, in which case isinstance()
951 will return true if the first argument is an instance of any of the
952 things contained in the second argument tuple. E.g.
953
954 isinstance(x, (A, B))
955
956 returns true if x is an instance of A or B.
957
Guido van Rossum9074ef62001-10-16 21:34:49 +0000958Extension modules
959
960- thread.start_new_thread() now returns the thread ID (previously None).
961
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000962- binascii has now two quopri support functions, a2b_qp and b2a_qp.
963
Guido van Rossumc524d952001-10-19 01:31:59 +0000964- readline now supports setting the startup_hook and the
965 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000966
Guido van Rossumc524d952001-10-19 01:31:59 +0000967- os and posix supports chroot(), setgroups() and unsetenv() where
968 available. The stat(), fstat(), statvfs() and fstatvfs() functions
969 now return "pseudo-sequences" -- the various fields can now be
970 accessed as attributes (e.g. os.stat("/").st_mtime) but for
971 backwards compatibility they also behave as a fixed-length sequence.
972 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000973 attributes.
974
975- time: localtime(), gmtime() and strptime() now return a
976 pseudo-sequence similar to the os.stat() return value, with
977 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000978
Guido van Rossum9074ef62001-10-16 21:34:49 +0000979- Decompression objects in the zlib module now accept an optional
980 second parameter to decompress() that specifies the maximum amount
981 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000982
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000983- optional SSL support in the socket module now exports OpenSSL
984 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
985 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000986 automatically seed its PRNG. Also, the keyfile and certfile
987 arguments to socket.ssl() are now optional.
988
989- posixmodule (and by extension, the os module on POSIX platforms) now
990 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000991
Guido van Rossum9074ef62001-10-16 21:34:49 +0000992Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000993
Tim Peters7402f792001-10-02 03:53:41 +0000994- doctest now excludes functions and classes not defined by the module
995 being tested, thanks to Tim Hochberg.
996
Fred Drakecb7a6b52001-10-22 18:41:51 +0000997- HotShot, a new profiler implemented using a C-based callback, has
998 been added. This substantially reduces the overhead of profiling,
999 but it is still quite preliminary. Support modules and
1000 documentation will be added in upcoming releases (before 2.2 final).
1001
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001002- profile now produces correct output in situations where an exception
1003 raised in Python is cleared by C code (e.g. hasattr()). This used
1004 to cause wrong output, including spurious claims of recursive
1005 functions and attribution of time spent to the wrong function.
1006
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001007 The code and documentation for the derived OldProfile and HotProfile
1008 profiling classes was removed. The code hasn't worked for years (if
1009 you tried to use them, they raised exceptions). OldProfile
1010 intended to reproduce the behavior of the profiler Python used more
1011 than 7 years ago, and isn't interesting anymore. HotProfile intended
1012 to provide a faster profiler (but producing less information), and
1013 that's a worthy goal we intend to meet via a different approach (but
1014 without losing information).
1015
Tim Peterscce092d2001-10-09 05:31:56 +00001016- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001017 a much better system-specific calibration constant. The constant can
1018 now be specified in an instance constructor, or as a Profile class or
1019 instance variable, instead of by editing profile.py's source code.
1020 Calibration must still be done manually (see the docs for the profile
1021 module).
1022
1023 Note that Profile.calibrate() must be overriden by subclasses.
1024 Improving the accuracy required exploiting detailed knowledge of
1025 profiler internals; the earlier method abstracted away the details
1026 and measured a simplified model instead, but consequently computed
1027 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001028
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001029- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001030 which indicates whether output is intended for the header 'Q'
1031 encoding.
1032
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001033- The SocketServer.ThreadingMixIn class now closes the request after
1034 finish_request() returns. (Not when it errors out though.)
1035
Barry Warsawf6fb1712001-10-19 05:35:40 +00001036- The nntplib module's NNTP.body() method has grown a `file' argument
1037 to allow saving the message body to a file.
1038
1039- The email package has added a class email.Parser.HeaderParser which
1040 only parses headers and does not recurse into the message's body.
1041 Also, the module/class MIMEAudio has been added for representing
1042 audio data (contributed by Anthony Baxter).
1043
1044- ftplib should be able to handle files > 2GB.
1045
1046- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1047 ON, and OFF.
1048
Fred Drakecb7a6b52001-10-22 18:41:51 +00001049- xml.dom.minidom NodeList objects now support the length attribute
1050 and item() method as required by the DOM specifications.
1051
Guido van Rossumed554f62001-10-02 23:15:37 +00001052Tools/Demos
1053
1054- Demo/dns was removed. It no longer serves any purpose; a package
1055 derived from it is now maintained by Anthony Baxter, see
1056 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001057
Barry Warsawf6fb1712001-10-19 05:35:40 +00001058- The freeze tool has been made more robust, and two new options have
1059 been added: -X and -E.
1060
Tim Petersabf925f2001-09-28 21:53:42 +00001061Build
1062
Barry Warsawf6fb1712001-10-19 05:35:40 +00001063- configure will use CXX in LINKCC if CXX is used to build main() and
1064 the system requires to link a C++ main using the C++ compiler.
1065
Tim Petersabf925f2001-09-28 21:53:42 +00001066C API
1067
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001068- The documentation for the tp_compare slot is updated to require that
1069 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1070 not correct. This is not yet enforced but will be enforced in
1071 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1072 "NotImplemented". Right now, -1 should be used for an error return.
1073
Tim Petersd38b1c72001-09-30 05:09:37 +00001074- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1075 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1076 as long) arguments.
1077
Guido van Rossum3c288632001-10-16 21:13:49 +00001078- PyThread_start_new_thread() now returns a long int giving the thread
1079 ID, if one can be calculated; it returns -1 for error, 0 if no
1080 thread ID is calculated (this is an incompatible change, but only
1081 the thread module used this API). This code has only really been
1082 tested on Linux and Windows; other platforms please beware (and
1083 report any bugs or strange behavior).
1084
Guido van Rossum1c486092001-10-19 02:05:35 +00001085- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1086 input.
1087
Tim Petersabf925f2001-09-28 21:53:42 +00001088New platforms
1089
1090Tests
1091
1092Windows
1093
Tim Peters04cf1d32001-10-09 22:39:40 +00001094- Installer: If you install IDLE, and don't disable file-extension
1095 registration, a new "Edit with IDLE" context (right-click) menu entry
1096 is created for .py and .pyw files.
1097
Tim Peters1ce3cf72001-10-01 17:58:40 +00001098- The signal module now supports SIGBREAK on Windows, thanks to Steven
1099 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1100 action remains to call Win32 ExitProcess(). This can be changed via
1101 signal.signal(). For example:
1102
1103 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1104 # (SIGINT) behavior.
1105 import signal
1106 signal.signal(signal.SIGBREAK,
1107 signal.default_int_handler)
1108
1109 try:
1110 while 1:
1111 pass
1112 except KeyboardInterrupt:
1113 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1114 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1115 # program without the possibility for any Python-level cleanup).
1116 print "Clean exit"
1117
Tim Petersabf925f2001-09-28 21:53:42 +00001118
Tim Petersb07352e2001-09-08 01:25:47 +00001119What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001120Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001121===========================
1122
Guido van Rossum808eea72001-09-25 04:15:41 +00001123Type/class unification and new-style classes
1124
1125- pydoc and inspect are now aware of new-style classes;
1126 e.g. help(list) at the interactive prompt now shows proper
1127 documentation for all operations on list objects.
1128
1129- Applications using Jim Fulton's ExtensionClass module can now safely
1130 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1131 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1132 examples also work again. It is hoped that Gtk and Boost also work
1133 with 2.2a4 and beyond. (If you can confirm this, please write
1134 webmaster@python.org; if there are still problems, please open a bug
1135 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001136
Tim Peters66c1a522001-09-24 21:17:50 +00001137- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001138 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001139 in the constructed property object. fget, fset and fdel weren't
1140 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1141 associate a docstring with a property.
1142
Guido van Rossum808eea72001-09-25 04:15:41 +00001143- Comparison overloading is now more completely implemented. For
1144 example, a str subclass instance can properly be compared to a str
1145 instance, and it can properly overload comparison. Ditto for most
1146 other built-in object types.
1147
1148- The repr() of new-style classes has changed; instead of <type
1149 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1150 *except* for built-in types, which are still rendered as <type
1151 'Foo'> (to avoid upsetting existing code that might parse or
1152 otherwise rely on repr() of certain type objects).
1153
1154- The repr() of new-style objects is now always <Foo object at XXX>;
1155 previously, it was sometimes <Foo instance at XXX>.
1156
1157- For new-style classes, what was previously called __getattr__ is now
1158 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001159 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001160 one in classic classes is defined which is called only if regular
1161 attribute access raises AttributeError; to catch *all* attribute
1162 access, you can use __getattribute__ (for new-style classes). If
1163 both are defined, __getattribute__ is called first, and if it raises
1164 AttributeError, __getattr__ is called.
1165
1166- The __class__ attribute of new-style objects can be assigned to.
1167 The new class must have the same C-level object layout as the old
1168 class.
1169
1170- The builtin file type can be subclassed now. In the usual pattern,
1171 "file" is the name of the builtin type, and file() is a new builtin
1172 constructor, with the same signature as the builtin open() function.
1173 file() is now the preferred way to open a file.
1174
1175- Previously, __new__ would only see sequential arguments passed to
1176 the type in a constructor call; __init__ would see both sequential
1177 and keyword arguments. This made no sense whatsoever any more, so
1178 now both __new__ and __init__ see all arguments.
1179
1180- Previously, hash() applied to an instance of a subclass of str or
1181 unicode always returned 0. This has been repaired.
1182
1183- Previously, an operation on an instance of a subclass of an
1184 immutable type (int, long, float, complex, tuple, str, unicode),
1185 where the subtype didn't override the operation (and so the
1186 operation was handled by the builtin type), could return that
1187 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001188 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001189 with the same value as s.
1190
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001191- Provisional support for pickling new-style objects has been added.
1192
Guido van Rossum808eea72001-09-25 04:15:41 +00001193Core
1194
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001195- file.writelines() now accepts any iterable object producing strings.
1196
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001197- PyUnicode_FromEncodedObject() now works very much like
1198 PyObject_Str(obj) in that it tries to use __str__/tp_str
1199 on the object if the object is not a string or buffer. This
1200 makes unicode() behave like str() when applied to non-string/buffer
1201 objects.
1202
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001203- PyFile_WriteObject now passes Unicode objects to the file's write
1204 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001205 of a print statement must support Unicode objects, i.e. they must
1206 at least convert them into ASCII strings.
1207
Guido van Rossum624c8af2001-09-18 15:21:04 +00001208- Thread scheduling on Solaris should be improved; it is no longer
1209 necessary to insert a small sleep at the start of a thread in order
1210 to let other runnable threads be scheduled.
1211
Tim Petersb07352e2001-09-08 01:25:47 +00001212Library
1213
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001214- StringIO.StringIO instances and cStringIO.StringIO instances support
1215 read character buffer compatible objects for their .write() methods.
1216 These objects are converted to strings and then handled as such
1217 by the instances.
1218
Barry Warsaw2f600732001-09-24 04:28:10 +00001219- The "email" package has been added. This is basically a port of the
1220 mimelib package <http://sf.net/projects/mimelib> with API changes
1221 and some implementations updated to use iterators and generators.
1222
Tim Peters8a9c2842001-09-22 21:30:22 +00001223- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1224 restores the ability of Tools/scripts/ndiff.py to start producing output
1225 before the entire comparison is complete.
1226
Barry Warsaw58b072d2001-09-22 04:44:21 +00001227- StringIO.StringIO instances and cStringIO.StringIO instances support
1228 iteration just like file objects (i.e. their .readline() method is
1229 called for each iteration until it returns an empty string).
1230
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001231- The codecs module has grown four new helper APIs to access
1232 builtin codecs: getencoder(), getdecoder(), getreader(),
1233 getwriter().
1234
Guido van Rossum624c8af2001-09-18 15:21:04 +00001235- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1236 simplifies writing XML RPC servers.
1237
Barry Warsaw647d5e82001-09-28 17:01:02 +00001238- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001239 after interpretation of symbolic links. On non-Unix systems, this
1240 is an alias for os.path.abspath().
1241
Tim Peters16a77ad2001-09-08 04:00:12 +00001242- operator.indexOf() (PySequence_Index() in the C API) now works with any
1243 iterable object.
1244
Guido van Rossum624c8af2001-09-18 15:21:04 +00001245- smtplib now supports various authentication and security features of
1246 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001247
Guido van Rossum624c8af2001-09-18 15:21:04 +00001248- hmac: a new module implementing keyed hashing for message
1249 authentication.
1250
1251- mimetypes now recognizes more extensions and file types. At the
1252 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001253
Guido van Rossum624c8af2001-09-18 15:21:04 +00001254- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001255 Python 2.2 bytecode generation. It has also been promoted from a
1256 Tool to a standard library package. (Tools/compiler still exists as
1257 a sample driver.)
1258
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001259Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001260
Tim Petersb07352e2001-09-08 01:25:47 +00001261Build
1262
Guido van Rossum624c8af2001-09-18 15:21:04 +00001263- Large file support (LFS) is now automatic when the platform supports
1264 it; no more manual configuration tweaks are needed. On Linux, at
1265 least, it's possible to have a system whose C library supports large
1266 files but whose kernel doesn't; in this case, large file support is
1267 still enabled but doesn't do you any good unless you upgrade your
1268 kernel or share your Python executable with another system whose
1269 kernel has large file support.
1270
1271- The configure script now supplies plausible defaults in a
1272 cross-compilation environment. This doesn't mean that the supplied
1273 values are always correct, or that cross-compilation now works
1274 flawlessly -- but it's a first step (and it shuts up most of
1275 autoconf's warnings about AC_TRY_RUN).
1276
1277- The Unix build is now a bit less chatty, courtesy of the parser
1278 generator. The build is completely silent (except for errors) when
1279 using "make -s", thanks to a -q option to setup.py.
1280
Tim Petersb07352e2001-09-08 01:25:47 +00001281C API
1282
Guido van Rossum624c8af2001-09-18 15:21:04 +00001283- The "structmember" API now supports some new flag bits to deny read
1284 and/or write access to attributes in restricted execution mode.
1285
Tim Petersb07352e2001-09-08 01:25:47 +00001286New platforms
1287
Guido van Rossum624c8af2001-09-18 15:21:04 +00001288- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1289 (http://familiar.handhelds.org).
1290
Tim Petersb07352e2001-09-08 01:25:47 +00001291Tests
1292
Tim Peters8a9c2842001-09-22 21:30:22 +00001293- The "classic" standard tests, which work by comparing stdout to
1294 an expected-output file under Lib/test/output/, no longer stop at
1295 the first mismatch. Instead the test is run to completion, and a
1296 variant of ndiff-style comparison is used to report all differences.
1297 This is much easier to understand than the previous style of reporting.
1298
1299- The unittest-based standard tests now use regrtest's test_main()
1300 convention, instead of running as a side-effect of merely being
1301 imported. This allows these tests to be run in more natural and
1302 flexible ways as unittests, outside the regrtest framework.
1303
1304- regrtest.py is much better integrated with unittest and doctest now,
1305 especially in regard to reporting errors.
1306
Tim Petersb07352e2001-09-08 01:25:47 +00001307Windows
1308
Guido van Rossum624c8af2001-09-18 15:21:04 +00001309- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001310 that support it (NTFS under Windows 2000). See "What's New in
1311 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001312
Tim Petersb07352e2001-09-08 01:25:47 +00001313
Tim Petersedc99312001-08-22 21:36:50 +00001314What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001315Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001316===========================
1317
1318Core
1319
Tim Peters9fffa3e2001-09-04 05:14:19 +00001320- Conversion of long to float now raises OverflowError if the long is too
1321 big to represent as a C double.
1322
Tim Peters32f453e2001-09-03 08:35:41 +00001323- The 3-argument builtin pow() no longer allows a third non-None argument
1324 if either of the first two arguments is a float, or if both are of
1325 integer types and the second argument is negative (in which latter case
1326 the arguments are converted to float, so this is really the same
1327 restriction).
1328
Tim Peters5d2b77c2001-09-03 05:47:38 +00001329- The builtin dir() now returns more information, and sometimes much
1330 more, generally naming all attributes of an object, and all attributes
1331 reachable from the object via its class, and from its class's base
1332 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1333 an empty list. In 2.2a3,
1334
1335 >>> dir([])
1336 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1337 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1338 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1339 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1340 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1341 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1342 'reverse', 'sort']
1343
1344 dir(module) continues to return only the module's attributes, though.
1345
Tim Petersbdee63f2001-09-02 03:40:59 +00001346- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001347 than raising OverflowError. This is a partial implementation of PEP
1348 237. You can use -Wdefault::OverflowWarning to enable a warning for
1349 this situation, and -Werror::OverflowWarning to revert to the old
1350 OverflowError exception.
1351
Guido van Rossum61c345f2001-09-04 03:26:15 +00001352- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001353 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001354 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1355 -Qold, meaning the / operator has its classic meaning and no
1356 warnings are issued. Using -Qwarn issues a run-time warning about
1357 all uses of classic division for int and long arguments; -Qwarnall
1358 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001359 (for use with fixdiv.py).
1360 [Note: the remainder of this paragraph (preserved below) became
1361 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1362 <obsolete>
1363 Using -Qnew is questionable; it turns on new division by default, but
1364 only in the __main__ module. You can usefully combine -Qwarn or
1365 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1366 warns about classic division everywhere else.
1367 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001368
Tim Petersbdee63f2001-09-02 03:40:59 +00001369- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001370 long, float, str, unicode, and tuple. (The types complex, list and
1371 dictionary can also be subclassed; this was introduced earlier.)
1372 Note that restrictions apply when subclassing immutable built-in
1373 types: you can only affect the value of the instance by overloading
1374 __new__. You can add mutable attributes, and the subclass instances
1375 will have a __dict__ attribute, but you cannot change the "value"
1376 (as implemented by the base class) of an immutable subclass instance
1377 once it is created.
1378
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001379- The dictionary constructor now takes an optional argument, a
1380 mapping-like object, and initializes the dictionary from its
1381 (key, value) pairs.
1382
Tim Petersbdee63f2001-09-02 03:40:59 +00001383- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001384 "cooperative super calls" in a multiple inheritance setting. For an
1385 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1386
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001387- A new built-in type, property, has been added. This enables the
1388 creation of "properties". These are attributes implemented by
1389 getter and setter functions (or only one of these for read-only or
1390 write-only attributes), without the need to override __getattr__.
1391 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001392
Tim Petersbdee63f2001-09-02 03:40:59 +00001393- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001394 liberalized, to allow leading zeroes. Examples of literals now
1395 legal that were SyntaxErrors before:
1396
1397 00.0 0e3 0100j 07.5 00000000000000000008.
1398
Tim Petersbdee63f2001-09-02 03:40:59 +00001399- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001400 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1401
Tim Petersedc99312001-08-22 21:36:50 +00001402Library
1403
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001404- telnetlib includes symbolic names for the options, and support for
1405 setting an option negotiation callback.
1406
Tim Petersa40c7932001-09-05 22:36:56 +00001407- The new C standard no longer requires that math libraries set errno to
1408 ERANGE on overflow. For platform libraries that exploit this new
1409 freedom, Python's overflow-checking was wholly broken. A new overflow-
1410 checking scheme attempts to repair that, but may not be reliable on all
1411 platforms (C doesn't seem to provide anything both useful and portable
1412 in this area anymore).
1413
Martin v. Löwis44f86962001-09-05 13:44:54 +00001414- Asynchronous timeout actions are available through the new class
1415 threading.Timer.
1416
Tim Peters78526162001-09-05 00:53:45 +00001417- math.log and math.log10 now return sensible results for even huge
1418 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1419
Tim Petersbdee63f2001-09-02 03:40:59 +00001420- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001421 currently held. See the docs for the imp module.
1422
Tim Petersbdee63f2001-09-02 03:40:59 +00001423- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001424 dumps containing ints written on platforms where Python ints are 8 bytes.
1425 When read on a box where Python ints are 4 bytes, such values are
1426 converted to Python longs.
1427
Tim Petersbdee63f2001-09-02 03:40:59 +00001428- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001429 code objects is no longer allowed. This plugs a security hole.
1430
Steve Purcell6091cd62001-09-06 16:05:17 +00001431- unittest.TestResult instances no longer store references to tracebacks
1432 generated by test failures. This prevents unexpected dangling references
1433 to objects that should be garbage collected between tests.
1434
Tim Petersedc99312001-08-22 21:36:50 +00001435Tools
1436
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001437- Tools/scripts/fixdiv.py has been added which can be used to fix
1438 division operators as per PEP 238.
1439
Tim Petersedc99312001-08-22 21:36:50 +00001440Build
1441
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001442- If you are an adventurous person using Mac OS X you may want to look at
1443 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1444 application, which can be used for experimenting with Carbon or Cocoa.
1445 Discussion of this on pythonmac-sig, please.
1446
Tim Peters7eea37e2001-09-04 22:08:56 +00001447C API
1448
1449- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001450
Tim Peters9fffa3e2001-09-04 05:14:19 +00001451- Note that PyLong_AsDouble can fail! This has always been true, but no
1452 callers checked for it. It's more likely to fail now, because overflow
1453 errors are properly detected now. The proper way to check:
1454
1455 double x = PyLong_AsDouble(some_long_object);
1456 if (x == -1.0 && PyErr_Occurred()) {
1457 /* The conversion failed. */
1458 }
1459
Tim Petersbdee63f2001-09-02 03:40:59 +00001460- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001461 compile but will not participate in GC. To upgrade an extension
1462 module:
1463
1464 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001465
Neil Schemenauer4042c692001-08-30 15:38:01 +00001466 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1467 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001468
Neil Schemenauer4042c692001-08-30 15:38:01 +00001469 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1470 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001471
Neil Schemenauer4042c692001-08-30 15:38:01 +00001472 - remove PyGC_HEAD_SIZE from object size calculations
1473
1474 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1475
Tim Petersbdee63f2001-09-02 03:40:59 +00001476- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001477 These can be used safely to construct string objects from a
1478 sprintf-style format string (similar to the format string supported
1479 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001480
Tim Petersedc99312001-08-22 21:36:50 +00001481New platforms
1482
Tim Petersb7da0902001-09-02 23:01:43 +00001483- Stephen Hansen contributed patches sufficient to get a clean compile
1484 under Borland C (Windows), but he reports problems running it and ran
1485 out of time to complete the port. Volunteers? Expect a MemoryError
1486 when importing the types module; this is probably shallow, and
1487 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001488
Tim Petersedc99312001-08-22 21:36:50 +00001489Tests
1490
1491Windows
1492
Tim Peters6e13a562001-09-06 00:32:15 +00001493- Large file support is now enabled on Win32 platforms as well as on
1494 Win64. This means that, for example, you can use f.tell() and f.seek()
1495 to manipulate files larger than 2 gigabytes (provided you have enough
1496 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001497 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1498 filesize limit, and large file support makes no difference there.
1499 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1500 NTFS has no practical limit on file size, and files of any size can be
1501 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001502
Tim Petersbdee63f2001-09-02 03:40:59 +00001503- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001504 points to command.com (patch from Brian Quinlan).
1505
Tim Petersedc99312001-08-22 21:36:50 +00001506
Tim Peters20f51a72001-07-21 02:31:40 +00001507What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001508Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001509===========================
1510
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001511Build
1512
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001513- Tim Peters developed a brand new Windows installer using Wise 8.1,
1514 generously donated to us by Wise Solutions.
1515
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001516- configure supports a new option --enable-unicode, with the values
1517 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1518 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001519
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001520- A new configure option --enable-framework builds a Mac OS X framework,
1521 which "make frameworkinstall" will install. This provides a starting
1522 point for more mac-like functionality, join pythonmac-sig@python.org
1523 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001524
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001525- The NeXT platform is no longer supported.
1526
1527- The `new' module is now statically linked.
1528
Tim Peters0afb6092001-08-15 06:06:44 +00001529Tools
1530
1531- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001532 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001533 the module docstring for details.
1534
Tim Peters20f51a72001-07-21 02:31:40 +00001535Tests
1536
Tim Peters5e824c32001-08-12 22:25:01 +00001537- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001538 platforms, allowing to give clearer test result output. regrtest
1539 also has optional --use/-u switch to run normally disabled tests
1540 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001541
Tim Peters20f51a72001-07-21 02:31:40 +00001542- Several new tests in the standard test suite, with special thanks to
1543 Nick Mathewson.
1544
1545Core
1546
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001547- The floor division operator // has been added as outlined in PEP
1548 238. The / operator still provides classic division (and will until
1549 Python 3.0) unless "from __future__ import division" is included, in
1550 which case the / operator will provide true division. The operator
1551 module provides truediv() and floordiv() functions. Augmented
1552 assignment variants are included, as are the equivalent overloadable
1553 methods and C API methods. See the PEP for a full discussion:
1554 <http://python.sf.net/peps/pep-0238.html>
1555
Tim Peters6cd6a822001-08-17 22:11:27 +00001556- Future statements are now effective in simulated interactive shells
1557 (like IDLE). This should "just work" by magic, but read Michael
1558 Hudson's "Future statements in simulated shells" PEP 264 for full
1559 details: <http://python.sf.net/peps/pep-0264.html>.
1560
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001561- The type/class unification (PEP 252-253) was integrated into the
1562 trunk and is not so tentative any more (the exact specification of
1563 some features is still tentative). A lot of work has done on fixing
1564 bugs and adding robustness and features (performance still has to
1565 come a long way).
1566
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001567- Warnings about a mismatch in the Python API during extension import
1568 now use the Python warning framework (which makes it possible to
1569 write filters for these warnings).
1570
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001571- A function's __dict__ (aka func_dict) will now always be a
1572 dictionary. It used to be possible to delete it or set it to None,
1573 but now both actions raise TypeErrors. It is still legal to set it
1574 to a dictionary object. Getting func.__dict__ before any attributes
1575 have been assigned now returns an empty dictionary instead of None.
1576
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001577- A new command line option, -E, was added which disables the use of
1578 all environment variables, or at least those that are specifically
1579 significant to Python. Usually those have a name starting with
1580 "PYTHON". This was used to fix a problem where the tests fail if
1581 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1582 older distribution.
1583
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001584Library
1585
Tim Peters5e824c32001-08-12 22:25:01 +00001586- New class Differ and new functions ndiff() and restore() in difflib.py.
1587 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001588 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001589
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001590- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1591 value using the minimal quoting required for the value; more
1592 reliable than using xml.sax.saxutils.escape() for attribute values.
1593
1594- Readline completion support for cmd.Cmd was added.
1595
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001596- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1597
1598- Added function threading.BoundedSemaphore()
1599
1600- Added Ka-Ping Yee's cgitb.py module.
1601
1602- The `new' module now exposes the CO_xxx flags.
1603
Martin v. Löwis560da622001-11-24 09:24:51 +00001604- The gc module offers the get_referents function.
1605
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001606New platforms
1607
1608C API
1609
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001610- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1611 which provide a cross-platform implementations for the
1612 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1613 the standard sprintf() and vsprintf() C lib APIs, these versions
1614 apply bounds checking on the used buffer which enhances protection
1615 against buffer overruns.
1616
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001617- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001618 and extensions using different Unicode widths is rendered next to
1619 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001620 will result in an ImportError. Unicode extensions writers must make
1621 sure to check the Unicode width compatibility in their extensions by
1622 using at least one of the mangled Unicode APIs in the extension.
1623
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001624- Two new flags METH_NOARGS and METH_O are available in method definition
1625 tables to simplify implementation of methods with no arguments and a
1626 single untyped argument. Calling such methods is more efficient than
1627 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1628 deprecated.
1629
Tim Petersc1731372001-08-04 08:12:36 +00001630Windows
1631
1632- "import module" now compiles module.pyw if it exists and nothing else
1633 relevant is found.
1634
Tim Peters20f51a72001-07-21 02:31:40 +00001635
Guido van Rossum55a78992001-07-17 17:22:32 +00001636What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001637Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001638===========================
1639
1640Core
Tim Petersa814db52001-05-14 07:05:58 +00001641
Tim Peters6d6c1a32001-08-02 04:15:00 +00001642- TENTATIVELY, a large amount of code implementing much of what's
1643 described in PEP 252 (Making Types Look More Like Classes) and PEP
1644 253 (Subtyping Built-in Types) was added. This will be released
1645 with Python 2.2a1. Documentation will be provided separately
1646 through http://www.python.org/2.2/. The purpose of releasing this
1647 with Python 2.2a1 is to test backwards compatibility. It is
1648 possible, though not likely, that a decision is made not to release
1649 this code as part of 2.2 final, if any serious backwards
1650 incompapatibilities are found during alpha testing that cannot be
1651 repaired.
1652
Guido van Rossum55a78992001-07-17 17:22:32 +00001653- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001654 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001655 more 'yield' statements. See PEP 255. Since this adds a new
1656 keyword to the language, this feature must be enabled by including a
1657 future statement: "from __future__ import generators" (see PEP 236).
1658 Generators will become a standard feature in a future release
1659 (probably 2.3). Without this future statement, 'yield' remains an
1660 ordinary identifier, but a warning is issued each time it is used.
1661 (These warnings currently don't conform to the warnings framework of
1662 PEP 230; we intend to fix this in 2.2a2.)
1663
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001664- The UTF-16 codec was modified to be more RFC compliant. It will now
1665 only remove BOM characters at the start of the string and then
1666 only if running in native mode (UTF-16-LE and -BE won't remove a
1667 leading BMO character).
1668
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001669- Strings now have a new method .decode() to complement the already
1670 existing .encode() method. These two methods provide direct access
1671 to the corresponding decoders and encoders of the registered codecs.
1672
1673 To enhance the usability of the .encode() method, the special
1674 casing of Unicode object return values was dropped (Unicode objects
1675 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001676
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001677 Both methods will now return whatever the codec in charge of the
1678 requested encoding returns as object, e.g. Unicode codecs will
1679 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1680 will return u"äöü"). This enables codec writer to create codecs
1681 for various simple to use conversions.
1682
1683 New codecs were added to demonstrate these new features (the .encode()
1684 and .decode() columns indicate the type of the returned objects):
1685
1686 Name | .encode() | .decode() | Description
1687 ----------------------------------------------------------------------
1688 uu | string | string | UU codec (e.g. for email)
1689 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001690 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001691 zlib | string | string | zlib compression
1692 hex | string | string | 2-byte hex codec
1693 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1694
Mark Hammond2a0af792001-05-14 03:09:36 +00001695- Some operating systems now support the concept of a default Unicode
1696 encoding for file system operations. Notably, Windows supports 'mbcs'
1697 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001698 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001699 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001700
1701 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001702 functions that return filenames (such as os.listdir()) to return Python
1703 string objects pre-encoded using the default file system encoding for
1704 the platform. As this encoding is likely to be different from Python's
1705 default encoding, converting this name to a Unicode object before passing
1706 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001707 would attempt to use its default encoding (generally ASCII) rather than
1708 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001709
Tim Petersa814db52001-05-14 07:05:58 +00001710 In general, this change simply removes surprises when working with
1711 Unicode and the file system, making these operations work as you expect,
1712 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001713 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001714
Tim Peters61dff2b2001-05-08 15:43:37 +00001715- Float (and complex) literals in source code were evaluated to full
1716 precision only when running from a .py file; the same code loaded from a
1717 .pyc (or .pyo) file could suffer numeric differences starting at about the
1718 12th significant decimal digit. For example, on a machine with IEEE-754
1719 floating arithmetic,
1720
1721 x = 9007199254740992.0
1722 print long(x)
1723
1724 printed 9007199254740992 if run directly from .py, but 9007199254740000
1725 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1726 str(float) instead of repr(float) when building code objects. marshal
1727 now uses repr(float) instead, which should reproduce floats to full
1728 machine precision (assuming the platform C float<->string I/O conversion
1729 functions are of good quality).
1730
1731 This may cause floating-point results to change in some cases, and
1732 usually for the better, but may also cause numerically unstable
1733 algorithms to break.
1734
Tim Peters2f228e72001-05-13 00:19:31 +00001735- The implementation of dicts suffers fewer collisions, which has speed
1736 benefits. However, the order in which dict entries appear in dict.keys(),
1737 dict.values() and dict.items() may differ from previous releases for a
1738 given dict. Nothing is defined about this order, so no program should
1739 rely on it. Nevertheless, it's easy to write test cases that rely on the
1740 order by accident, typically because of printing the str() or repr() of a
1741 dict to an "expected results" file. See Lib/test/test_support.py's new
1742 sortdict(dict) function for a simple way to display a dict in sorted
1743 order.
1744
Tim Peters7a3bfc32001-06-12 01:22:22 +00001745- Many other small changes to dicts were made, resulting in faster
1746 operation along the most common code paths.
1747
Guido van Rossum10315822001-05-01 20:54:30 +00001748- Dictionary objects now support the "in" operator: "x in dict" means
1749 the same as dict.has_key(x).
1750
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001751- The update() method of dictionaries now accepts generic mapping
1752 objects. Specifically the argument object must support the .keys()
1753 and __getitem__() methods. This allows you to say, for example,
1754 {}.update(UserDict())
1755
Guido van Rossum10315822001-05-01 20:54:30 +00001756- Iterators were added; this is a generalized way of providing values
1757 to a for loop. See PEP 234. There's a new built-in function iter()
1758 to return an iterator. There's a new protocol to get the next value
1759 from an iterator using the next() method (in Python) or the
1760 tp_iternext slot (in C). There's a new protocol to get iterators
1761 using the __iter__() method (in Python) or the tp_iter slot (in C).
1762 Iterating (i.e. a for loop) over a dictionary generates its keys.
1763 Iterating over a file generates its lines.
1764
Tim Petersf553f892001-05-01 20:45:31 +00001765- The following functions were generalized to work nicely with iterator
1766 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001767 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001768 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1769 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001770 join() method of strings
1771 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001772 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1773 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001774 right-hand side of assignment statements with multiple targets, such as
1775 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001776
Tim Petersd85e1022001-05-11 21:51:48 +00001777- Accessing module attributes is significantly faster (for example,
1778 random.random or os.path or yourPythonModule.yourAttribute).
1779
Tim Peterse63415e2001-05-08 04:38:29 +00001780- Comparing dictionary objects via == and != is faster, and now works even
1781 if the keys and values don't support comparisons other than ==.
1782
Tim Peters95bf9392001-05-10 08:32:44 +00001783- Comparing dictionaries in ways other than == and != is slower: there were
1784 insecurities in the dict comparison implementation that could cause Python
1785 to crash if the element comparison routines for the dict keys and/or
1786 values mutated the dicts. Making the code bulletproof slowed it down.
1787
Tim Peterseb28ef22001-06-02 05:27:19 +00001788- Collisions in dicts are resolved via a new approach, which can help
1789 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001790 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001791 faster now. Thanks to Christian Tismer for pointing out the cause and
1792 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001793
Tim Peters52e155e2001-06-16 05:42:57 +00001794- repr() is much faster for large containers (dict, list, tuple).
1795
1796
Tim Petersa814db52001-05-14 07:05:58 +00001797Library
1798
Fred Drake960fdf92001-07-20 18:38:26 +00001799- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1800 were added to the string module. These a locale-indenpendent
1801 constants, unlike letters, lowercase, and uppercase. These are now
1802 use in appropriate locations in the standard library.
1803
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001804- The flags used in dlopen calls can now be configured using
1805 sys.setdlopenflags and queried using sys.getdlopenflags.
1806
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001807- Fredrik Lundh's xmlrpclib is now a standard library module. This
1808 provides full client-side XML-RPC support. In addition,
1809 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1810 one asyncore-based). Thanks to Eric Raymond for the documentation.
1811
Guido van Rossum643d3912001-07-05 14:46:25 +00001812- The xrange() object is simplified: it no longer supports slicing,
1813 repetition, comparisons, efficient 'in' checking, the tolist()
1814 method, or the start, stop and step attributes. See PEP 260.
1815
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001816- A new function fnmatch.filter to filter lists of file names was added.
1817
Barry Warsawffd674d2001-05-22 16:00:10 +00001818- calendar.py uses month and day names based on the current locale.
1819
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001820- strop is now *really* obsolete (this was announced before with 1.6),
1821 and issues DeprecationWarning when used (except for the four items
1822 that are still imported into string.py).
1823
Tim Petersa814db52001-05-14 07:05:58 +00001824- Cookie.py now sorts key+value pairs by key in output strings.
1825
1826- pprint.isrecursive(object) didn't correctly identify recursive objects.
1827 Now it does.
1828
Tim Peters95b3f782001-05-14 18:39:41 +00001829- pprint functions now much faster for large containers (tuple, list, dict).
1830
Tim Peters7b9542a2001-06-10 23:40:19 +00001831- New 'q' and 'Q' format codes in the struct module, corresponding to C
1832 types "long long" and "unsigned long long" (on Windows, __int64). In
1833 native mode, these can be used only when the platform C compiler supports
1834 these types (when HAVE_LONG_LONG is #define'd by the Python config
1835 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001836 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1837 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001838
Guido van Rossum83213cc2001-06-12 16:48:52 +00001839- The site module installs a new built-in function 'help' that invokes
1840 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1841 it displays a message reminding the user to use 'help()' or
1842 'help(object)'.
1843
Tim Petersa814db52001-05-14 07:05:58 +00001844Tests
1845
1846- New test_mutants.py runs dict comparisons where the key and value
1847 comparison operators mutute the dicts randomly during comparison. This
1848 rapidly causes Python to crash under earlier releases (not for the faint
1849 of heart: it can also cause Win9x to freeze or reboot!).
1850
1851- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001852 pprint.isreadable() return sensible results. Also verifies that simple
1853 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001854
Tim Peters4324aa32001-05-28 22:30:08 +00001855C API
1856
1857- Removed the unused last_is_sticky argument from the internal
1858 _PyTuple_Resize(). If this affects you, you were cheating.
1859
1860
Guido van Rossum55a78992001-07-17 17:22:32 +00001861======================================================================
1862
1863
Guido van Rossumffe13be2001-04-16 18:46:45 +00001864What's New in Python 2.1 (final)?
1865=================================
1866
1867We only changed a few things since the last release candidate, all in
1868Python library code:
1869
1870- A bug in the locale module was fixed that affected locales which
1871 define no grouping for numeric formatting.
1872
1873- A few bugs in the weakref module's implementations of weak
1874 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1875 and the test suite was updated to check for these bugs.
1876
1877- An old bug in the os.path.walk() function (introduced in Python
1878 2.0!) was fixed: a non-existent file would cause an exception
1879 instead of being ignored.
1880
1881- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1882 PyChecker.
1883
1884
Guido van Rossum5b08f132001-04-16 02:05:23 +00001885What's New in Python 2.1c2?
1886===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001887
Guido van Rossum5b08f132001-04-16 02:05:23 +00001888A flurry of small changes, and one showstopper fixed in the nick of
1889time made it necessary to release another release candidate. The list
1890here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001891
Guido van Rossum5b08f132001-04-16 02:05:23 +00001892Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001893
Guido van Rossum5b08f132001-04-16 02:05:23 +00001894- Tim discovered a nasty bug in the dictionary code, caused by
1895 PyDict_Next() calling dict_resize(), and the GC code's use of
1896 PyDict_Next() violating an assumption in dict_items(). This was
1897 fixed with considerable amounts of band-aid, but the net effect is a
1898 saner and more robust implementation.
1899
1900- Made a bunch of symbols static that were accidentally global.
1901
1902Build and Ports
1903
1904- The setup.py script didn't check for a new enough version of zlib
1905 (1.1.3 is needed). Now it does.
1906
1907- Changed "make clean" target to also remove shared libraries.
1908
1909- Added a more general warning about the SGI Irix optimizer to README.
1910
1911Library
1912
1913- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1914 omitted the slash between host and file.html.
1915
1916- The mailbox module's _Mailbox class contained a completely broken
1917 and undocumented seek() method. Ripped it out.
1918
1919- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1920 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1921
1922- Fixed a few last-minute bugs in unittest.
1923
1924Extensions
1925
1926- Reverted the patch to the OpenSSL code in socketmodule.c to support
1927 RAND_status() and the EGD, and the subsequent patch that tried to
1928 fix it for pre-0.9.5 versions; the problem with the patch is that on
1929 some systems it issues a warning whenever socket is imported, and
1930 that's unacceptable.
1931
1932Tests
1933
1934- Fixed the pickle tests to work with "import test.test_pickle".
1935
1936- Tweaked test_locale.py to actually run the test Windows.
1937
1938- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1939 not "wb" (which is not a valid mode at all).
1940
1941- Fix pstats browser crashes. Import readline if it exists to make
1942 the user interface nicer.
1943
1944- Add "import thread" to the top of test modules that import the
1945 threading module (test_asynchat and test_threadedtempfile). This
1946 prevents test failures caused by a broken threading module resulting
1947 from a previously caught failed import.
1948
1949- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1950 needed on some platforms (e.g. Solaris 8) when the tests are run
1951 twice in succession.
1952
1953- Skip rather than fail test_sunaudiodev if no audio device is found.
1954
1955
1956What's New in Python 2.1c1?
1957===========================
1958
1959This list was significantly updated when 2.1c2 was released; the 2.1c1
1960release didn't mention most changes that were actually part of 2.1c1:
1961
1962Legal
1963
1964- Copyright was assigned to the Python Software Foundation (PSF) and a
1965 PSF license (very similar to the CNRI license) was added.
1966
1967- The CNRI copyright notice was updated to include 2001.
1968
1969Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001970
Guido van Rossumc9932722001-04-12 02:31:27 +00001971- After a public outcry, assignment to __debug__ is no longer illegal;
1972 instead, a warning is issued. It will become illegal in 2.2.
1973
Guido van Rossum5b08f132001-04-16 02:05:23 +00001974- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1975 "%#x" now always prepends "0x", even if the value is zero.
1976
1977- Fixed some nits in the bytecode compiler.
1978
1979- Fixed core dumps when calling certain kinds of non-functions.
1980
1981- Fixed various core dumps caused by reference count bugs.
1982
1983Build and Ports
1984
1985- Use INSTALL_SCRIPT to install script files.
1986
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001987- New port: SCO Unixware 7, by Billy G. Allie.
1988
Guido van Rossum5b08f132001-04-16 02:05:23 +00001989- Updated RISCOS port.
1990
1991- Updated BeOS port and notes.
1992
1993- Various other porting problems resolved.
1994
1995Library
1996
1997- The TERMIOS and SOCKET modules are now truly obsolete and
1998 unnecessary. Their symbols are incorporated in the termios and
1999 socket modules.
2000
2001- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
2002 better tests for pickling.
2003
2004- threading: make Condition.wait() robust against KeyboardInterrupt.
2005
2006- zipfile: add support to zipfile to support opening an archive
2007 represented by an open file rather than a file name. Fix bug where
2008 the archive was not properly closed. Fixed a bug in this bugfix
2009 where flush() was called for a read-only file.
2010
2011- imputil: added an uninstall() method to the ImportManager.
2012
2013- Canvas: fixed bugs in lower() and tkraise() methods.
2014
2015- SocketServer: API change (added overridable close_request() method)
2016 so that the TCP server can explicitly close the request.
2017
2018- pstats: Eric Raymond added a simple interactive statistics browser,
2019 invoked when the module is run as a script.
2020
2021- locale: fixed a problem in format().
2022
2023- webbrowser: made it work when the BROWSER environment variable has a
2024 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
2025 KDE 2. Fixed some other nits.
2026
2027- unittest: changes to allow using a different exception than
2028 AssertionError, and added a few more function aliases. Some other
2029 small changes.
2030
2031- urllib, urllib2: fixed redirect problems and a coupleof other nits.
2032
2033- asynchat: fixed a critical bug in asynchat that slipped through the
2034 2.1b2 release. Fixed another rare bug.
2035
2036- Fix some unqualified except: clauses (always a bad code example).
2037
2038XML
2039
2040- pyexpat: new API get_version_string().
2041
2042- Fixed some minidom bugs.
2043
2044Extensions
2045
2046- Fixed a core dump in _weakref. Removed the weakref.mapping()
2047 function (it adds nothing to the API).
2048
2049- Rationalized the use of header files in the readline module, to make
2050 it compile (albeit with some warnings) with the very recent readline
2051 4.2, without breaking for earlier versions.
2052
2053- Hopefully fixed a buffering problem in linuxaudiodev.
2054
2055- Attempted a fix to make the OpenSSL support in the socket module
2056 work again with pre-0.9.5 versions of OpenSSL.
2057
2058Tests
2059
2060- Added a test case for asynchat and asyncore.
2061
2062- Removed coupling between tests where one test failing could break
2063 another.
2064
2065Tools
2066
2067- Ping added an interactive help browser to pydoc, fixed some nits
2068 in the rest of the pydoc code, and added some features to his
2069 inspect module.
2070
2071- An updated python-mode.el version 4.1 which integrates Ken
2072 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2073 much nicer in XEmacs and Emacs. When stepping through your program
2074 with pdb, in either the shell window or the *Python* window, the
2075 source file and line will be tracked by an arrow. Very cool!
2076
2077- IDLE: syntax warnings in interactive mode are changed into errors.
2078
2079- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002080 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002081
2082- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002083
Barry Warsaw11e89c72001-04-11 20:37:57 +00002084
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002085What's New in Python 2.1 beta 2?
2086================================
2087
Guido van Rossum053ae352001-03-22 14:17:21 +00002088(Unlisted are many fixed bugs, more documentation, etc.)
2089
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002090Core language, builtins, and interpreter
2091
Guido van Rossum053ae352001-03-22 14:17:21 +00002092- The nested scopes work (enabled by "from __future__ import
2093 nested_scopes") is completed; in particular, the future now extends
2094 into code executed through exec, eval() and execfile(), and into the
2095 interactive interpreter.
2096
2097- When calling a base class method (e.g. BaseClass.__init__(self)),
2098 this is now allowed even if self is not strictly spoken a class
2099 instance (e.g. when using metaclasses or the Don Beaudry hook).
2100
2101- Slice objects are now comparable but not hashable; this prevents
2102 dict[:] from being accepted but meaningless.
2103
2104- Complex division is now calculated using less braindead algorithms.
2105 This doesn't change semantics except it's more likely to give useful
2106 results in extreme cases. Complex repr() now uses full precision
2107 like float repr().
2108
2109- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2110
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002111- It is illegal to assign to the name __debug__, which is set when the
2112 interpreter starts. It is effectively a compile-time constant.
2113
2114- A warning will be issued if a global statement for a variable
2115 follows a use or assignment of that variable.
2116
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002117Standard library
2118
Guido van Rossum053ae352001-03-22 14:17:21 +00002119- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2120 inspired by JUnit), is now part of the standard library. You now
2121 have a choice of two testing frameworks: unittest requires you to
2122 write testcases as separate code, doctest gathers them from
2123 docstrings. Both approaches have their advantages and
2124 disadvantages.
2125
2126- A new module Tix was added, which wraps the Tix extension library
2127 for Tk. With that module, it is not necessary to statically link
2128 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2129 require" command. See Demo/tix/.
2130
2131- tzparse.py is now obsolete.
2132
2133- In gzip.py, the seek() and tell() methods are removed -- they were
2134 non-functional anyway, and it's better if callers can test for their
2135 existence with hasattr().
2136
2137Python/C API
2138
2139- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2140 that's already in the dictionary during a PyDict_Next() iteration.
2141 This used to fail occasionally when a dictionary resize operation
2142 could be triggered that would rehash all the keys. All other
2143 modifications to the dictionary are still off-limits during a
2144 PyDict_Next() iteration!
2145
2146- New extended APIs related to passing compiler variables around.
2147
2148- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2149 implement isinstance() and issubclass().
2150
2151- Py_BuildValue() now has a "D" conversion to create a Python complex
2152 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002153
Fred Drake4e262a92001-03-22 18:26:47 +00002154- Extensions types which support weak references must now set the
2155 field allocated for the weak reference machinery to NULL themselves;
2156 this is done to avoid the cost of checking each object for having a
2157 weakly referencable type in PyObject_INIT(), since most types are
2158 not weakly referencable.
2159
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002160- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2161 free variables and cell variables to and from the frame's f_locals.
2162
2163- Variants of several functions defined in pythonrun.h have been added
2164 to support the nested_scopes future statement. The variants all end
2165 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2166 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2167 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002168 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002169
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002170Distutils
2171
2172- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2173 into the release tree.
2174
Tim Peters0e57abf2001-05-02 07:39:38 +00002175- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002176 (an uninstaller, more customization of the installer's display)
2177
2178- from Jack Jansen: added Mac-specific code to generate a dialog for
2179 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002180 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002181 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002182
2183- added 'platforms' and 'keywords' to the set of metadata that can be
2184 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002185
2186- applied patches from Jason Tishler to make the compiler class work with
2187 Cygwin.
2188
2189
Tim Peters2fe289a2001-03-01 22:19:38 +00002190What's New in Python 2.1 beta 1?
2191================================
Tim Petersd66595f2001-02-04 03:09:53 +00002192
2193Core language, builtins, and interpreter
2194
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002195- Following an outcry from the community about the amount of code
2196 broken by the nested scopes feature introduced in 2.1a2, we decided
2197 to make this feature optional, and to wait until Python 2.2 (or at
2198 least 6 months) to make it standard. The option can be enabled on a
2199 per-module basis by adding "from __future__ import nested_scopes" at
2200 the beginning of a module (before any other statements, but after
2201 comments and an optional docstring). See PEP 236 (Back to the
2202 __future__) for a description of the __future__ statement. PEP 227
2203 (Statically Nested Scopes) has been updated to reflect this change,
2204 and to clarify the semantics in a number of endcases.
2205
2206- The nested scopes code, when enabled, has been hardened, and most
2207 bugs and memory leaks in it have been fixed.
2208
2209- Compile-time warnings are now generated for a number of conditions
2210 that will break or change in meaning when nested scopes are enabled:
2211
2212 - Using "from...import *" or "exec" without in-clause in a function
2213 scope that also defines a lambda or nested function with one or
2214 more free (non-local) variables. The presence of the import* or
2215 bare exec makes it impossible for the compiler to determine the
2216 exact set of local variables in the outer scope, which makes it
2217 impossible to determine the bindings for free variables in the
2218 inner scope. To avoid the warning about import *, change it into
2219 an import of explicitly name object, or move the import* statement
2220 to the global scope; to avoid the warning about bare exec, use
2221 exec...in... (a good idea anyway -- there's a possibility that
2222 bare exec will be deprecated in the future).
2223
2224 - Use of a global variable in a nested scope with the same name as a
2225 local variable in a surrounding scope. This will change in
2226 meaning with nested scopes: the name in the inner scope will
2227 reference the variable in the outer scope rather than the global
2228 of the same name. To avoid the warning, either rename the outer
2229 variable, or use a global statement in the inner function.
2230
Neil Schemenauera35c6882001-02-27 04:45:05 +00002231- An optional object allocator has been included. This allocator is
2232 optimized for Python objects and should be faster and use less memory
2233 than the standard system allocator. It is not enabled by default
2234 because of possible thread safety problems. The allocator is only
2235 protected by the Python interpreter lock and it is possible that some
2236 extension modules require a thread safe allocator. The object
2237 allocator can be enabled by providing the "--with-pymalloc" option to
2238 configure.
2239
Tim Petersd66595f2001-02-04 03:09:53 +00002240Standard library
2241
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002242- pyexpat now detects the expat version if expat.h defines it. A
2243 number of additional handlers are provided, which are only available
2244 since expat 1.95. In addition, the methods SetParamEntityParsing and
2245 GetInputContext of Parser objects are available with 1.95.x
2246 only. Parser objects now provide the ordered_attributes and
2247 specified_attributes attributes. A new module expat.model was added,
2248 which offers a number of additional constants if 1.95.x is used.
2249
2250- xml.dom offers the new functions registerDOMImplementation and
2251 getDOMImplementation.
2252
2253- xml.dom.minidom offers a toprettyxml method. A number of DOM
2254 conformance issues have been resolved. In particular, Element now
2255 has an hasAttributes method, and the handling of namespaces was
2256 improved.
2257
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002258- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2259 getting information about live Python code, and pydoc.py, a module
2260 for interactively converting docstrings to HTML or text.
2261 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002262 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002263 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2264 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002265
Tim Peters1eff7962001-03-01 02:31:33 +00002266- New library module difflib.py, primarily packaging the SequenceMatcher
2267 class at the heart of the popular ndiff.py file-comparison tool.
2268
2269- doctest.py (a framework for verifying Python code examples in docstrings)
2270 is now part of the std library.
2271
Tim Petersd66595f2001-02-04 03:09:53 +00002272Windows changes
2273
Guido van Rossume3955a82001-03-02 14:05:59 +00002274- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2275 small GUI that lets you browse the module docstrings using your
2276 default web browser.
2277
Tim Peters1eff7962001-03-01 02:31:33 +00002278- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2279 Platforms) is implemented. See
2280
2281 http://python.sourceforge.net/peps/pep-0235.html
2282
2283 for full details, especially the "Current Lower-Left Semantics" section.
2284 The new Windows import rules are simpler than before:
2285
2286 A. If the PYTHONCASEOK environment variable exists, same as
2287 before: silently accept the first case-insensitive match of any
2288 kind; raise ImportError if none found.
2289
2290 B. Else search sys.path for the first case-sensitive match; raise
2291 ImportError if none found.
2292
2293 The same rules have been implented on other platforms with case-
2294 insensitive but case-preserving filesystems too (including Cygwin, and
2295 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002296
Tim Peters25a9ce32001-02-19 07:06:36 +00002297- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2298 what it's supposed to do (and does do under NT and 2000) via direct
2299 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002300 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002301 all Win9x systems before.
2302
Tim Peters1eff7962001-03-01 02:31:33 +00002303- Build: Subproject _test (effectively) renamed to _testcapi.
2304
Tim Peters2fe289a2001-03-01 22:19:38 +00002305New platforms
2306
2307- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2308 Thanks to Steven Majewski!
2309
2310- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2311 Tishler!
2312
Guido van Rossum9089b272001-03-02 06:49:50 +00002313- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2314 Schwertberger! See RISCOS/README for more information -- it seems
2315 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002316 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002317
Tim Peters25a9ce32001-02-19 07:06:36 +00002318
Tim Petersd7b5e882001-01-25 03:36:26 +00002319What's New in Python 2.1 alpha 2?
2320=================================
Tim Peters40ead762001-01-27 05:35:26 +00002321
Tim Petersd7b5e882001-01-25 03:36:26 +00002322Core language, builtins, and interpreter
2323
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002324- Scopes nest. If a name is used in a function or class, but is not
2325 local, the definition in the nearest enclosing function scope will
2326 be used. One consequence of this change is that lambda statements
2327 could reference variables in the namespaces where the lambda is
2328 defined. In some unusual cases, this change will break code.
2329
2330 In all previous version of Python, names were resolved in exactly
2331 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002332 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002333 function A is defined within a function B, the names bound in B are
2334 not visible in A. The new rules make names bound in B visible in A,
2335 unless A contains a name binding that hides the binding in B.
2336
2337 Section 4.1 of the reference manual describes the new scoping rules
2338 in detail. The test script in Lib/test/test_scope.py demonstrates
2339 some of the effects of the change.
2340
2341 The new rules will cause existing code to break if it defines nested
2342 functions where an outer function has local variables with the same
2343 name as globals or builtins used by the inner function. Example:
2344
2345 def munge(str):
2346 def helper(x):
2347 return str(x)
2348 if type(str) != type(''):
2349 str = helper(str)
2350 return str.strip()
2351
2352 Under the old rules, the name str in helper() is bound to the
2353 builtin function str(). Under the new rules, it will be bound to
2354 the argument named str and an error will occur when helper() is
2355 called.
2356
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002357- The compiler will report a SyntaxError if "from ... import *" occurs
2358 in a function or class scope. The language reference has documented
2359 that this case is illegal, but the compiler never checked for it.
2360 The recent introduction of nested scope makes the meaning of this
2361 form of name binding ambiguous. In a future release, the compiler
2362 may allow this form when there is no possibility of ambiguity.
2363
Tim Peters40ead762001-01-27 05:35:26 +00002364- repr(string) is easier to read, now using hex escapes instead of octal,
2365 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2366
2367 >>> "\texample \r\n" + chr(0) + chr(255)
2368 '\texample \r\n\x00\xff' # in 2.1
2369 '\011example \015\012\000\377' # in 2.0
2370
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002371- Functions are now compared and hashed by identity, not by value, since
2372 the func_code attribute is writable.
2373
Fred Drakefb9d7122001-02-01 20:00:40 +00002374- Weak references (PEP 205) have been added. This involves a few
2375 changes in the core, an extension module (_weakref), and a Python
2376 module (weakref). The weakref module is the public interface. It
2377 includes support for "explicit" weak references, proxy objects, and
2378 mappings with weakly held values.
2379
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002380- A 'continue' statement can now appear in a try block within the body
2381 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002382 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002383
Tim Petersd7b5e882001-01-25 03:36:26 +00002384Standard library
2385
Barry Warsaw30dbd142001-01-31 22:14:01 +00002386- mailbox.py now has a new class, PortableUnixMailbox which is
2387 identical to UnixMailbox but uses a more portable scheme for
2388 determining From_ separators. Also, the constructors for all the
2389 classes in this module have a new optional `factory' argument, which
2390 is a callable used when new message classes must be instantiated by
2391 the next() method.
2392
Tim Petersd7b5e882001-01-25 03:36:26 +00002393- random.py is now self-contained, and offers all the functionality of
2394 the now-deprecated whrandom.py. See the docs for details. random.py
2395 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002396 and restoring the internal state of the generator; and jumpahead(n),
2397 for quickly forcing the internal state to be the same as if n calls to
2398 random() had been made. The latter is particularly useful for multi-
2399 threaded programs, creating one instance of the random.Random() class for
2400 each thread, then using .jumpahead() to force each instance to use a
2401 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002402
Tim Peters0de88fc2001-02-01 04:59:18 +00002403- random.py's seed() function is new. For bit-for-bit compatibility with
2404 prior releases, use the whseed function instead. The new seed function
2405 addresses two problems: (1) The old function couldn't produce more than
2406 about 2**24 distinct internal states; the new one about 2**45 (the best
2407 that can be done in the Wichmann-Hill generator). (2) The old function
2408 sometimes produced identical internal states when passed distinct
2409 integers, and there was no simple way to predict when that would happen;
2410 the new one guarantees to produce distinct internal states for all
2411 arguments in [0, 27814431486576L).
2412
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002413- The socket module now supports raw packets on Linux. The socket
2414 family is AF_PACKET.
2415
Tim Peters9ea17ac2001-02-02 05:57:15 +00002416- test_capi.py is a start at running tests of the Python C API. The tests
2417 are implemented by the new Modules/_testmodule.c.
2418
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002419- A new extension module, _symtable, provides provisional access to the
2420 internal symbol table used by the Python compiler. A higher-level
2421 interface will be added on top of _symtable in a future release.
2422
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002423- Removed the obsolete soundex module.
2424
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002425- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2426 the isSameNode method; NamedNodeMap the get method.
2427
2428- xml.sax.expatreader supports the lexical handler property; it
2429 generates comment, startCDATA, and endCDATA events.
2430
Tim Petersee826f82001-01-31 19:39:44 +00002431Windows changes
2432
2433- Build procedure: the zlib project is built in a different way that
2434 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002435 the zlib binary used. See PCbuild\readme.txt for details. Your old
2436 zlib-related directories can be deleted; you'll need to download fresh
2437 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002438
Tim Peters9ea17ac2001-02-02 05:57:15 +00002439- Build: New subproject _test for the benefit of test_capi.py (see above).
2440
Tim Petersb16c56f2001-02-02 21:24:51 +00002441- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2442 interface to some Python compiler internals).
2443
2444- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002445 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002446
Tim Petersa3a3a032000-11-30 05:22:44 +00002447What's New in Python 2.1 alpha 1?
2448=================================
2449
2450Core language, builtins, and interpreter
2451
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002452- There is a new Unicode companion to the PyObject_Str() API
2453 called PyObject_Unicode(). It behaves in the same way as the
2454 former, but assures that the returned value is an Unicode object
2455 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002456
Guido van Rossumf98eda02001-01-17 15:54:45 +00002457- The comparison operators support "rich comparison overloading" (PEP
2458 207). C extension types can provide a rich comparison function in
2459 the new tp_richcompare slot in the type object. The cmp() function
2460 and the C function PyObject_Compare() first try the new rich
2461 comparison operators before trying the old 3-way comparison. There
2462 is also a new C API PyObject_RichCompare() (which also falls back on
2463 the old 3-way comparison, but does not constrain the outcome of the
2464 rich comparison to a Boolean result).
2465
2466 The rich comparison function takes two objects (at least one of
2467 which is guaranteed to have the type that provided the function) and
2468 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2469 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2470 object, which may be NotImplemented (in which case the tp_compare
2471 slot function is used as a fallback, if defined).
2472
2473 Classes can overload individual comparison operators by defining one
2474 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002475 __ge__. There are no explicit "reflected argument" versions of
2476 these; instead, __lt__ and __gt__ are each other's reflection,
2477 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2478 reflection (similar at the C level). No other implications are
2479 made; in particular, Python does not assume that == is the Boolean
2480 inverse of !=, or that < is the Boolean inverse of >=. This makes
2481 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002482
2483 Classes or types that want to implement (in)equality tests but not
2484 the ordering operators (i.e. unordered types) should implement ==
2485 and !=, and raise an error for the ordering operators.
2486
Guido van Rossuma88479f2001-01-18 14:28:08 +00002487 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002488 Boolean; e.g. a matrix type might want to return a matrix of bits
2489 for A < B, giving elementwise comparisons. Such types should ensure
2490 that any interpretation of their value in a Boolean context raises
2491 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2492 at the C level) to always raise an exception.
2493
Guido van Rossuma88479f2001-01-18 14:28:08 +00002494- Complex numbers use rich comparisons to define == and != but raise
2495 an exception for <, <=, > and >=. Unfortunately, this also means
2496 that cmp() of two complex numbers raises an exception when the two
2497 numbers differ. Since it is not mathematically meaningful to compare
2498 complex numbers except for equality, I hope that this doesn't break
2499 too much code.
2500
Tim Peters3389f192001-02-18 08:48:49 +00002501- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002502 not defined by the language, other than that it's arbitrary but
2503 consistent (see the Reference Manual). An implementation detail changed
2504 in 2.1a1 such that None now compares less than any other object. Code
2505 relying on this new behavior (like code that relied on the previous
2506 behavior) does so at its own risk.
2507
Barry Warsaw573b5412001-01-15 20:43:18 +00002508- Functions and methods now support getting and setting arbitrarily
2509 named attributes (PEP 232). Functions have a new __dict__
2510 (a.k.a. func_dict) which hold the function attributes. Methods get
2511 and set attributes on their underlying im_func. It is a TypeError
2512 to set an attribute on a bound method.
2513
Guido van Rossum051e3352001-01-15 19:11:10 +00002514- The xrange() object implementation has been improved so that
2515 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2516 limitation that in this case len(xrange(sys.maxint)) can't be
2517 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2518 work fine as long as the index i doesn't actually reach 2**31.
2519 (Python uses regular ints for sequence and string indices; fixing
2520 that is much more work.)
2521
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002522- Two changes to from...import:
2523
Guido van Rossumba381232001-02-03 15:06:40 +00002524 1) "from M import X" now works even if (after loading module M)
2525 sys.modules['M'] is not a real module; it's basically a getattr()
2526 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002527
2528 2) "from M import *" now looks for M.__all__ to decide which names to
2529 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2530 filters out names starting with '_' as before. Whether or not
2531 __all__ exists, there's no restriction on the type of M.
2532
Guido van Rossumf61f1662001-01-10 20:13:55 +00002533- File objects have a new method, xreadlines(). This is the fastest
2534 way to iterate over all lines in a file:
2535
2536 for line in file.xreadlines():
2537 ...do something to line...
2538
2539 See the xreadlines module (mentioned below) for how to do this for
2540 other file-like objects.
2541
2542- Even if you don't use file.xreadlines(), you may expect a speedup on
2543 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002544 quite a bit in platform-specific ways: on systems (like Linux) that
2545 support flockfile(), getc_unlocked(), and funlockfile(), those are
2546 used by default. On systems (like Windows) without getc_unlocked(),
2547 a complicated (but still thread-safe) method using fgets() is used by
2548 default.
2549
Tim Petersd52269b2001-01-25 06:23:18 +00002550 You can force use of the fgets() method by #define'ing
2551 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002552 getc_unlocked()).
2553
Tim Petersd52269b2001-01-25 06:23:18 +00002554 You can force fgets() not to be used by #define'ing
2555 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002556 test_bufio.py fails -- and let us know if it does!).
2557
2558- In addition, the fileinput module, while still slower than the other
2559 methods on most platforms, has been sped up too, by using
2560 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002561
2562- Support for run-time warnings has been added, including a new
2563 command line option (-W) to specify the disposition of warnings.
2564 See the description of the warnings module below.
2565
2566- Extensive changes have been made to the coercion code. This mostly
2567 affects extension modules (which can now implement mixed-type
2568 numerical operators without having to use coercion), but
2569 occasionally, in boundary cases the coercion semantics have changed
2570 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002571 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002572 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002573 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002574
Guido van Rossumf98eda02001-01-17 15:54:45 +00002575- In connection with the coercion changes, a new built-in singleton
2576 object, NotImplemented is defined. This can be returned for
2577 operations that wish to indicate they are not implemented for a
2578 particular combination of arguments. From C, this is
2579 Py_NotImplemented.
2580
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002581- The interpreter accepts now bytecode files on the command line even
2582 if they do not have a .pyc or .pyo extension. On Linux, after executing
2583
Martin v. Löwise214baa2001-02-04 22:37:56 +00002584import imp,sys,string
2585magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2586reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2587open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002588
2589 any byte code file can be used as an executable (i.e. as an argument
2590 to execve(2)).
2591
Tim Peters9940b802000-12-01 07:59:35 +00002592- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002593 character. In 1.6 and earlier, they never produced a sign,
2594 and raised an error if the value of the long was too large
2595 to fit in a Python int. In 2.0, they produced a sign if and
2596 only if too large to fit in an int. This was inconsistent
2597 across platforms (because the size of an int varies across
2598 platforms), and inconsistent with hex() and oct(). Example:
2599
2600 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002601 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002602 'ffffffbe' # in 2.0 and before, on 32-bit machines
2603 >>> hex(-0x42L)
2604 '-0x42L' # in all versions of Python
2605
Tim Peters9940b802000-12-01 07:59:35 +00002606 The behavior of %d formats for negative Python longs remains
2607 the same as in 2.0 (although in 1.6 and before, they raised
2608 an error if the long didn't fit in a Python int).
2609
2610 %u formats don't make sense for Python longs, but are allowed
2611 and treated the same as %d in 2.1. In 2.0, a negative long
2612 formatted via %u produced a sign if and only if too large to
2613 fit in an int. In 1.6 and earlier, a negative long formatted
2614 via %u raised an error if it was too big to fit in an int.
2615
Guido van Rossum3661d392000-12-12 22:10:31 +00002616- Dictionary objects have an odd new method, popitem(). This removes
2617 an arbitrary item from the dictionary and returns it (in the form of
2618 a (key, value) pair). This can be useful for algorithms that use a
2619 dictionary as a bag of "to do" items and repeatedly need to pick one
2620 item. Such algorithms normally end up running in quadratic time;
2621 using popitem() they can usually be made to run in linear time.
2622
Tim Peters36cdad12000-12-29 02:06:45 +00002623Standard library
2624
Thomas Woutersfe385252001-01-19 23:16:56 +00002625- In the time module, the time argument to the functions strftime,
2626 localtime, gmtime, asctime and ctime is now optional, defaulting to
2627 the current time (in the local timezone).
2628
Guido van Rossumda91f222001-01-15 16:36:08 +00002629- The ftplib module now defaults to passive mode, which is deemed a
2630 more useful default given that clients are often inside firewalls
2631 these days. Note that this could break if ftplib is used to connect
2632 to a *server* that is inside a firewall, from outside; this is
2633 expected to be a very rare situation. To fix that, you can call
2634 ftp.set_pasv(0).
2635
Martin v. Löwis10a27872001-01-13 09:54:41 +00002636- The module site now treats .pth files not only for path configuration,
2637 but also supports extensions to the initialization code: Lines starting
2638 with import are executed.
2639
Guido van Rossumf61f1662001-01-10 20:13:55 +00002640- There's a new module, warnings, which implements a mechanism for
2641 issuing and filtering warnings. There are some new built-in
2642 exceptions that serve as warning categories, and a new command line
2643 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2644 turns warnings into errors). warnings.warn(message[, category])
2645 issues a warning message; this can also be called from C as
2646 PyErr_Warn(category, message).
2647
2648- A new module xreadlines was added. This exports a single factory
2649 function, xreadlines(). The intention is that this code is the
2650 absolutely fastest way to iterate over all lines in an open
2651 file(-like) object:
2652
2653 import xreadlines
2654 for line in xreadlines.xreadlines(file):
2655 ...do something to line...
2656
2657 This is equivalent to the previous the speed record holder using
2658 file.readlines(sizehint). Note that if file is a real file object
2659 (as opposed to a file-like object), this is equivalent:
2660
2661 for line in file.xreadlines():
2662 ...do something to line...
2663
Tim Peters36cdad12000-12-29 02:06:45 +00002664- The bisect module has new functions bisect_left, insort_left,
2665 bisect_right and insort_right. The old names bisect and insort
2666 are now aliases for bisect_right and insort_right. XXX_right
2667 and XXX_left methods differ in what happens when the new element
2668 compares equal to one or more elements already in the list: the
2669 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002670 right. Code that doesn't care where equal elements end up should
2671 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002672
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002673- The new curses.panel module wraps the panel library that forms part
2674 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2675
Guido van Rossumf61f1662001-01-10 20:13:55 +00002676- The SocketServer module now sets the allow_reuse_address flag by
2677 default in the TCPServer class.
2678
2679- A new function, sys._getframe(), returns the stack frame pointer of
2680 the caller. This is intended only as a building block for
2681 higher-level mechanisms such as string interpolation.
2682
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002683- The pyexpat module supports a number of new handlers, which are
2684 available only in expat 1.2. If invocation of a callback fails, it
2685 will report an additional frame in the traceback. Parser objects
2686 participate now in garbage collection. If expat reports an unknown
2687 encoding, pyexpat will try to use a Python codec; that works only
2688 for single-byte charsets. The parser type objects is exposed as
2689 XMLParserObject.
2690
2691- xml.dom now offers standard definitions for symbolic node type and
2692 exception code constants, and a hierarchy of DOM exceptions. minidom
2693 was adjusted to use them.
2694
2695- The conformance of xml.dom.minidom to the DOM specification was
2696 improved. It detects a number of additional error cases; the
2697 previous/next relationship works even when the tree is modified;
2698 Node supports the normalize() method; NamedNodeMap, DocumentType and
2699 DOMImplementation classes were added; Element supports the
2700 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2701 method.
2702
Guido van Rossumf61f1662001-01-10 20:13:55 +00002703Build issues
2704
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002705- For Unix (and Unix-compatible) builds, configuration and building of
2706 extension modules is now greatly automated. Rather than having to
2707 edit the Modules/Setup file to indicate which modules should be
2708 built and where their include files and libraries are, a
2709 distutils-based setup.py script now takes care of building most
2710 extension modules. All extension modules built this way are built
2711 as shared libraries. Only a few modules that must be linked
2712 statically are still listed in the Setup file; you won't need to
2713 edit their configuration.
2714
2715- Python should now build out of the box on Cygwin. If it doesn't,
2716 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002717
2718- Python now always uses its own (renamed) implementation of getopt()
2719 -- there's too much variation among C library getopt()
2720 implementations.
2721
2722- C++ compilers are better supported; the CXX macro is always set to a
2723 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002724
Tim Petersd92dfe02000-12-12 01:18:41 +00002725Windows changes
2726
2727- select module: By default under Windows, a select() call
2728 can specify no more than 64 sockets. Python now boosts
2729 this Microsoft default to 512. If you need even more than
2730 that, see the MS docs (you'll need to #define FD_SETSIZE
2731 and recompile Python from source).
2732
Guido van Rossumf61f1662001-01-10 20:13:55 +00002733- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2734 subdirectory is no more!
2735
Tim Petersa3a3a032000-11-30 05:22:44 +00002736
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002737What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002738=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002739
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002740Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002741changes are in the file HISTORY. If you are making the jump directly
2742from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2743HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002744
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002745Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2746the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2747http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002748
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002749--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002750
2751======================================================================
2752
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002753What's new in 2.0 (since release candidate 1)?
2754==============================================
2755
2756Standard library
2757
2758- The copy_reg module was modified to clarify its intended use: to
2759 register pickle support for extension types, not for classes.
2760 pickle() will raise a TypeError if it is passed a class.
2761
2762- Fixed a bug in gettext's "normalize and expand" code that prevented
2763 it from finding an existing .mo file.
2764
2765- Restored support for HTTP/0.9 servers in httplib.
2766
Tim Peters989b7b92000-10-16 20:24:53 +00002767- The math module was changed to stop raising OverflowError in case of
2768 underflow, and return 0 instead in underflow cases. Whether Python
2769 used to raise OverflowError in case of underflow was platform-
2770 dependent (it did when the platform math library set errno to ERANGE
2771 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002772
2773- Fixed a bug in StringIO that occurred when the file position was not
2774 at the end of the file and write() was called with enough data to
2775 extend past the end of the file.
2776
2777- Fixed a bug that caused Tkinter error messages to get lost on
2778 Windows. The bug was fixed by replacing direct use of
2779 interp->result with Tcl_GetStringResult(interp).
2780
2781- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2782 redirect response.
2783
2784- Several changes were made to distutils: Some debugging code was
2785 removed from util. Fixed the installer used when an external zip
2786 program (like WinZip) is not found; the source code for this
2787 installer is in Misc/distutils. check_lib() was modified to behave
2788 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2789 test for whether installed modules are on sys.path was changed to
2790 use both normcase() and normpath().
2791
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002792- Several minor bugs were fixed in the xml package (the minidom,
2793 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002794
2795- The regression test driver (regrtest.py) behavior when invoked with
2796 -l changed: It now reports a count of objects that are recognized as
2797 garbage but not freed by the garbage collector.
2798
Tim Peters989b7b92000-10-16 20:24:53 +00002799- The regression test for the math module was changed to test
2800 exceptional behavior when the test is run in verbose mode. Python
2801 cannot yet guarantee consistent exception behavior across platforms,
2802 so the exception part of test_math is run only in verbose mode, and
2803 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002804
2805Internals
2806
2807- PyOS_CheckStack() has been disabled on Win64, where it caused
2808 test_sre to fail.
2809
2810Build issues
2811
2812- Changed compiler flags, so that gcc is always invoked with -Wall and
2813 -Wstrict-prototypes. Users compiling Python with GCC should see
2814 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002815 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002816 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002817
Tim Petersa3a3a032000-11-30 05:22:44 +00002818- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002819
2820Tools and other miscellany
2821
2822- The compiler in Tools/compiler was updated to support the new
2823 language features introduced in 2.0: extended print statement, list
2824 comprehensions, and augmented assignments. The new compiler should
2825 also be backwards compatible with Python 1.5.2; the compiler will
2826 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002827 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002828
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002829What's new in 2.0 release candidate 1 (since beta 2)?
2830=====================================================
2831
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002832What is release candidate 1?
2833
2834We believe that release candidate 1 will fix all known bugs that we
2835intend to fix for the 2.0 final release. This release should be a bit
2836more stable than the previous betas. We would like to see even more
2837widespread testing before the final release, so we are producing this
2838release candidate. The final release will be exactly the same unless
2839any show-stopping (or brown bag) bugs are found by testers of the
2840release candidate.
2841
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002842All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002843to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002844
2845Core language, builtins, and interpreter
2846
2847- A bug that caused crashes when __coerce__ was used with augmented
2848 assignment, e.g. +=, was fixed.
2849
2850- Raise ZeroDivisionError when raising zero to a negative number,
2851 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2852 power operator and the result of math.pow(0.0, -2.0) will vary by
2853 platform. On Linux, it raises a ValueError.
2854
2855- A bug in Unicode string interpolation was fixed that occasionally
2856 caused errors with formats including "%%". For example, the
2857 following expression "%% %s" % u"abc" no longer raises a TypeError.
2858
2859- Compilation of deeply nested expressions raises MemoryError instead
2860 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2861
2862- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2863 rendering them useless. They are now written in binary mode again.
2864
2865Standard library
2866
2867- Keyword arguments are now accepted for most pattern and match object
2868 methods in SRE, the standard regular expression engine.
2869
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002870- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002871 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002872
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002873- Several bugs in the Unicode handling and error handling in _tkinter
2874 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002875
2876- Fix memory management errors in Merge() and Tkapp_Call() routines.
2877
2878- Several changes were made to cStringIO to make it compatible with
2879 the file-like object interface and with StringIO. If operations are
2880 performed on a closed object, an exception is raised. The truncate
2881 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002882 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002883
2884- There were many changes made to the linuxaudiodev module and its
2885 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002886 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002887
2888 Note that this module is named poorly, because it should work
2889 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002890 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002891
2892 The module now raises exceptions when errors occur instead of
2893 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2894 audio) and defines a getptr() method that calls the
2895 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2896
2897- The library_version attribute, introduced in an earlier beta, was
2898 removed because it can not be supported with early versions of the C
2899 readline library, which provides no way to determine the version at
2900 compile-time.
2901
2902- The binascii module is now enabled on Win64.
2903
Tim Peters46446d62000-10-09 21:19:31 +00002904- tokenize.py no longer suffers "recursion depth" errors when parsing
2905 programs with very long string literals.
2906
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002907Internals
2908
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002909- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002910 which is called when the interpreter starts up to determine where
2911 the standard library is installed. These vulnerabilities affect all
2912 previous versions of Python and can be exploited by setting very
2913 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2914 setuid Python script, although use of the wrapper in
2915 Misc/setuid-prog.c will eliminate the vulnerability.
2916
2917- Fixed garbage collection bugs in instance creation that were
2918 triggered when errors occurred during initialization. The solution,
2919 applied in cPickle and in PyInstance_New(), is to call
2920 PyObject_GC_Init() after the initialization of the object's
2921 container attributes is complete.
2922
2923- pyexpat adds definitions of PyModule_AddStringConstant and
2924 PyModule_AddObject if the Python version is less than 2.0, which
2925 provides compatibility with PyXML on Python 1.5.2.
2926
2927- If the platform has a bogus definition for LONG_BIT (the number of
2928 bits in a long), an error will be reported at compile time.
2929
2930- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2931 collection crashes and possibly other, unreported crashes.
2932
2933- Fixed a memory leak in _PyUnicode_Fini().
2934
2935Build issues
2936
2937- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002938 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002939 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002940
2941- The mmap.PAGESIZE constant is now initialized using sysconf when
2942 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2943
2944- The md5 file should now compile on all platforms.
2945
2946- The select module now compiles on platforms that do not define
2947 POLLRDNORM and related constants.
2948
2949- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002950 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002951
Jeremy Hylton10921202000-10-09 18:34:12 +00002952- BeOS: A number of changes were made to the build and installation
2953 process. ar-fake now operates on a directory of object files.
2954 dl_export.h is gone, and its macros now appear on the mwcc command
2955 line during build on PPC BeOS.
2956
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002957- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002958 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002959
2960- Cygwin: Support for shared libraries, Tkinter, and sockets.
2961
2962- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2963
2964Tools and other miscellany
2965
2966- Removed debugging prints from main used with freeze.
2967
Tim Peters46446d62000-10-09 21:19:31 +00002968- IDLE auto-indent no longer crashes when it encounters Unicode
2969 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002970
2971What's new in 2.0 beta 2 (since beta 1)?
2972========================================
2973
2974Core language, builtins, and interpreter
2975
Tim Peters482c0212000-09-26 06:33:09 +00002976- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002977 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002978
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002979- Add -h and -V command line options to print the usage message and
2980 Python version number and exit immediately.
2981
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002982- eval() and exec accept Unicode objects as code parameters.
2983
2984- getattr() and setattr() now also accept Unicode objects for the
2985 attribute name, which are converted to strings using the default
2986 encoding before lookup.
2987
2988- Multiplication on string and Unicode now does proper bounds
2989 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2990 string is too long."
2991
2992- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002993 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002994
Jeremy Hylton1b618592000-09-26 05:32:36 +00002995
2996Standard library and extensions
2997
Guido van Rossum5b08f132001-04-16 02:05:23 +00002998- socket module: the OpenSSL code now adds support for RAND_status()
2999 and EGD (Entropy Gathering Device).
3000
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003001- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00003002 argument checking; it still takes no arguments.
3003
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003004- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003005
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003006- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003007
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003008- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003009
3010- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003011 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003012
3013- copy: Copy Unicode objects atomically.
3014
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003015- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003016
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003017- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003018
Fred Drake67233bc2000-09-26 16:40:27 +00003019- dbm: Add get() and setdefault() methods to dbm object. Add constant
3020 `library' to module that names the library used. Added doc strings
3021 and method names to error messages. Uses configure to determine
3022 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
3023 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003024
3025- distutils: Update to version 0.9.3.
3026
3027- dl: Add several dl.RTLD_ constants.
3028
3029- fpectl: Now supported on FreeBSD.
3030
3031- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
3032 found by the collector will be saved in gc.garbage. This is useful
3033 for debugging a program that creates reference cycles.
3034
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003035- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003036 of HTTP class. Do not close socket on zero-length response. Do not
3037 crash when server sends invalid content-length header.
3038
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003039- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003040
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003041- marshal: When reading a short, sign-extend on platforms where shorts
3042 are bigger than 16 bits. When reading a long, repair the unportable
3043 sign extension that was being done for 64-bit machines. (It assumed
3044 that signed right shift sign-extends.)
3045
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003046- operator: Add contains(), invert(), __invert__() as aliases for
3047 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003048
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003049- os: Add support for popen2() and popen3() on all platforms where
3050 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003051
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003052- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003053 clicking on a file in Explorer (or passing the file name to the
3054 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003055
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003056- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003057 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003058
3059- pickle: Now raises ValueError when an invalid pickle that contains
3060 a non-string repr where a string repr was expected. This behavior
3061 matches cPickle.
3062
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003063- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003064
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003065- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003066
3067- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003068 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003069 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003070
3071- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003072 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003073
3074- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003075 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003076 few cycles during startup since the first call to
3077 setdefaultencoding() will initialize the codec registry and the
3078 encodings package.
3079
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003080- socket: Support for size hint in readlines() method of object returned
3081 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003082
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003083- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003084 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003085 is followed by whitespace.
3086
Tim Petersa3a3a032000-11-30 05:22:44 +00003087- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003088
3089- struct: Check ranges for bytes and shorts.
3090
3091- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003092 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003093
3094- Tkinter: Image objects are now guaranteed to have unique ids. Set
3095 event.delta to zero if Tk version doesn't support mousewheel.
3096 Removed some debugging prints.
3097
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003098- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003099
Fred Drake67233bc2000-09-26 16:40:27 +00003100- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003101 which works around a bug in Norton AntiVirus 2000 that leads directly
3102 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003103
3104- xml: New version detection code allows PyXML to override standard
3105 XML package if PyXML version is greater than 0.6.1.
3106
Fred Drake64bb3802000-09-26 16:21:35 +00003107- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3108 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3109 tree only for nodes which are sufficiently interesting to a specific
3110 application. Does not provide the HTML-specific extensions. Still
3111 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003112
Fred Drake64bb3802000-09-26 16:21:35 +00003113- xml.sax: SAX 2 support for Python, including all the handler
3114 interfaces needed to process XML 1.0 compliant XML. Some
3115 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003116
Fred Drake64bb3802000-09-26 16:21:35 +00003117- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3118 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003119
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003120
Jeremy Hylton1b618592000-09-26 05:32:36 +00003121C API
3122
3123- Add three new convenience functions for module initialization --
3124 PyModule_AddObject(), PyModule_AddIntConstant(), and
3125 PyModule_AddStringConstant().
3126
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003127- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003128 removed and add #error to Python.h if NULL isn't defined after
3129 #include of stdio.h.
3130
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003131- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003132 backwards compatibility (at the source level) with old extensions.
3133
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003134- A wrapper API was added for signal() and sigaction(). Instead of
3135 either function, always use PyOS_getsig() to get a signal handler
3136 and PyOS_setsig() to set one. A new convenience typedef
3137 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003138
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003139- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003140 internal data buffer and size of a string object -- or the default
3141 encoded version of a Unicode object.
3142
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003143- PyString_Size() and PyString_AsString() accept Unicode objects.
3144
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003145- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003146 exists). INT_MAX and LONG_MAX will always be defined, even if
3147 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003148
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003149- PyFloat_FromString takes a second argument, pend, that was
3150 effectively useless. It is now officially useless but preserved for
3151 backwards compatibility. If the pend argument is not NULL, *pend is
3152 set to NULL.
3153
3154- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3155 for the attribute name. See note on getattr() above.
3156
3157- A few bug fixes to argument processing for Unicode.
3158 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3159 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3160 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003161 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003162
3163- Py_BuildValue accepts B format (for bgen-generated code).
3164
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003165
Jeremy Hylton1b618592000-09-26 05:32:36 +00003166Internals
3167
3168- On Unix, fix code for finding Python installation directory so that
3169 it works when argv[0] is a relative path.
3170
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003171- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003172 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003173 rather than by generating a copy of the object.
3174
Tim Peters482c0212000-09-26 06:33:09 +00003175- Several of the internal Unicode tables are much smaller now, and
3176 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003177
Jeremy Hylton97693b02000-09-26 17:42:51 +00003178- In the garbage collector: Fixed bug in collection of tuples. Fixed
3179 bug that caused some instances to be removed from the container set
3180 while they were still live. Fixed parsing in gc.set_debug() for
3181 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003182
3183- Fixed refcount problem in instance deallocation that only occurred
3184 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3185
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003186- On Windows, getpythonregpath is now protected against null data in
3187 registry key.
3188
3189- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003190 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003191
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003192
Jeremy Hylton1b618592000-09-26 05:32:36 +00003193Build and platform-specific issues
3194
3195- Better support of GNU Pth via --with-pth configure option.
3196
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003197- Python/C API now properly exposed to dynamically-loaded extension
3198 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003199
3200- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3201 Don't define MS_SYNC to be zero when it is undefined. Added missing
3202 prototypes in posixmodule.c.
3203
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003204- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003205 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003206
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003207- Fix largefile support on older NetBSD systems and OpenBSD by adding
3208 define for TELL64.
3209
3210
3211Tools and other miscellany
3212
3213- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3214
3215- freeze: The modulefinder now works with 2.0 opcodes.
3216
Tim Petersa3a3a032000-11-30 05:22:44 +00003217- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003218 Move hackery of sys.argv until after the Tk instance has been
3219 created, which allows the application-specific Tkinter
3220 initialization to be executed if present; also pass an explicit
3221 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003222
Jeremy Hylton1b618592000-09-26 05:32:36 +00003223
3224What's new in 2.0 beta 1?
3225=========================
3226
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003227Source Incompatibilities
3228------------------------
3229
3230None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3231such as single-argument append(), connect() and bind(), and changes to
3232str(long) and repr(float).
3233
3234
3235Binary Incompatibilities
3236------------------------
3237
3238- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3239with Python 2.0; these extensions will have to be rebuilt for Python
32402.0.
3241
3242- On Windows, attempting to import a third party extension built for
3243Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3244can do about this. Check your PYTHONPATH environment variable!
3245
3246- Python bytecode files (*.pyc and *.pyo) are not compatible between
3247releases.
3248
3249
3250Overview of Changes Since 1.6
3251-----------------------------
3252
3253There are many new modules (including brand new XML support through
3254the xml package, and i18n support through the gettext module); a list
3255of all new modules is included below. Lots of bugs have been fixed.
3256
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003257The process for making major new changes to the language has changed
3258since Python 1.6. Enhancements must now be documented by a Python
3259Enhancement Proposal (PEP) before they can be accepted.
3260
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003261There are several important syntax enhancements, described in more
3262detail below:
3263
3264 - Augmented assignment, e.g. x += 1
3265
3266 - List comprehensions, e.g. [x**2 for x in range(10)]
3267
3268 - Extended import statement, e.g. import Module as Name
3269
3270 - Extended print statement, e.g. print >> file, "Hello"
3271
3272Other important changes:
3273
3274 - Optional collection of cyclical garbage
3275
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003276Python Enhancement Proposal (PEP)
3277---------------------------------
3278
3279PEP stands for Python Enhancement Proposal. A PEP is a design
3280document providing information to the Python community, or describing
3281a new feature for Python. The PEP should provide a concise technical
3282specification of the feature and a rationale for the feature.
3283
3284We intend PEPs to be the primary mechanisms for proposing new
3285features, for collecting community input on an issue, and for
3286documenting the design decisions that have gone into Python. The PEP
3287author is responsible for building consensus within the community and
3288documenting dissenting opinions.
3289
3290The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003291
3292Augmented Assignment
3293--------------------
3294
3295This must have been the most-requested feature of the past years!
3296Eleven new assignment operators were added:
3297
Guido van Rossume905e952000-09-05 12:42:46 +00003298 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003299
3300For example,
3301
3302 A += B
3303
3304is similar to
3305
3306 A = A + B
3307
3308except that A is evaluated only once (relevant when A is something
3309like dict[index].attr).
3310
3311However, if A is a mutable object, A may be modified in place. Thus,
3312if A is a number or a string, A += B has the same effect as A = A+B
3313(except A is only evaluated once); but if a is a list, A += B has the
3314same effect as A.extend(B)!
3315
3316Classes and built-in object types can override the new operators in
3317order to implement the in-place behavior; the not-in-place behavior is
3318used automatically as a fallback when an object doesn't implement the
3319in-place behavior. For classes, the method name is derived from the
3320method name for the corresponding not-in-place operator by inserting
3321an 'i' in front of the name, e.g. __iadd__ implements in-place
3322__add__.
3323
3324Augmented assignment was implemented by Thomas Wouters.
3325
3326
3327List Comprehensions
3328-------------------
3329
3330This is a flexible new notation for lists whose elements are computed
3331from another list (or lists). The simplest form is:
3332
3333 [<expression> for <variable> in <sequence>]
3334
Guido van Rossum56db0952000-09-06 23:34:25 +00003335For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003336This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003337
3338You can also add a condition:
3339
3340 [<expression> for <variable> in <sequence> if <condition>]
3341
3342For example, [w for w in words if w == w.lower()] would yield the list
3343of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003344than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003345
3346You can also have nested for loops and more than one 'if' clause. For
3347example, here's a function that flattens a sequence of sequences::
3348
3349 def flatten(seq):
3350 return [x for subseq in seq for x in subseq]
3351
3352 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3353
3354This prints
3355
3356 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3357
3358List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003359Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003360
3361
3362Extended Import Statement
3363-------------------------
3364
3365Many people have asked for a way to import a module under a different
3366name. This can be accomplished like this:
3367
3368 import foo
3369 bar = foo
3370 del foo
3371
3372but this common idiom gets old quickly. A simple extension of the
3373import statement now allows this to be written as follows:
3374
3375 import foo as bar
3376
3377There's also a variant for 'from ... import':
3378
3379 from foo import bar as spam
3380
3381This also works with packages; e.g. you can write this:
3382
3383 import test.regrtest as regrtest
3384
3385Note that 'as' is not a new keyword -- it is recognized only in this
3386context (this is only possible because the syntax for the import
3387statement doesn't involve expressions).
3388
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003389Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003390
3391
3392Extended Print Statement
3393------------------------
3394
3395Easily the most controversial new feature, this extension to the print
3396statement adds an option to make the output go to a different file
3397than the default sys.stdout.
3398
3399For example, to write an error message to sys.stderr, you can now
3400write:
3401
3402 print >> sys.stderr, "Error: bad dog!"
3403
3404As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003405evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003406
3407 print >> None, "Hello world"
3408
3409is equivalent to
3410
3411 print "Hello world"
3412
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003413Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003414
3415
3416Optional Collection of Cyclical Garbage
3417---------------------------------------
3418
3419Python is now equipped with a garbage collector that can hunt down
3420cyclical references between Python objects. It's no replacement for
3421reference counting; in fact, it depends on the reference counts being
3422correct, and decides that a set of objects belong to a cycle if all
3423their reference counts can be accounted for from their references to
3424each other. This devious scheme was first proposed by Eric Tiedemann,
3425and brought to implementation by Neil Schemenauer.
3426
3427There's a module "gc" that lets you control some parameters of the
3428garbage collection. There's also an option to the configure script
3429that lets you enable or disable the garbage collection. In 2.0b1,
3430it's on by default, so that we (hopefully) can collect decent user
3431experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003432performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003433off by default in the final 2.0 release.
3434
3435
3436Smaller Changes
3437---------------
3438
3439A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3440map(None, seq1, seq2, ...) when the sequences have the same length;
3441i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3442the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003443zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003444
3445sys.version_info is a tuple (major, minor, micro, level, serial).
3446
3447Dictionaries have an odd new method, setdefault(key, default).
3448dict.setdefault(key, default) returns dict[key] if it exists; if not,
3449it sets dict[key] to default and returns that value. Thus:
3450
3451 dict.setdefault(key, []).append(item)
3452
3453does the same work as this common idiom:
3454
3455 if not dict.has_key(key):
3456 dict[key] = []
3457 dict[key].append(item)
3458
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003459There are two new variants of SyntaxError that are raised for
3460indentation-related errors: IndentationError and TabError.
3461
3462Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3463escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003464
3465The limits on the size of expressions and file in Python source code
3466have been raised from 2**16 to 2**32. Previous versions of Python
3467were limited because the maximum argument size the Python VM accepted
3468was 2**16. This limited the size of object constructor expressions,
3469e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3470limit was raised thanks to a patch by Charles Waldman that effectively
3471fixes the problem. It is now much more likely that you will be
3472limited by available memory than by an arbitrary limit in Python.
3473
3474The interpreter's maximum recursion depth can be modified by Python
3475programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3476limit is the maximum number of recursive calls that can be made by
3477Python code. The limit exists to prevent infinite recursion from
3478overflowing the C stack and causing a core dump. The default value is
34791000. The maximum safe value for a particular platform can be found
3480by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003481
3482New Modules and Packages
3483------------------------
3484
3485atexit - for registering functions to be called when Python exits.
3486
3487imputil - Greg Stein's alternative API for writing custom import
3488hooks.
3489
3490pyexpat - an interface to the Expat XML parser, contributed by Paul
3491Prescod.
3492
3493xml - a new package with XML support code organized (so far) in three
3494subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3495would fill a volume. There's a special feature whereby a
3496user-installed package named _xmlplus overrides the standard
3497xmlpackage; this is intended to give the XML SIG a hook to distribute
3498backwards-compatible updates to the standard xml package.
3499
3500webbrowser - a platform-independent API to launch a web browser.
3501
3502
Guido van Rossume905e952000-09-05 12:42:46 +00003503Changed Modules
3504---------------
3505
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003506array -- new methods for array objects: count, extend, index, pop, and
3507remove
3508
3509binascii -- new functions b2a_hex and a2b_hex that convert between
3510binary data and its hex representation
3511
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003512calendar -- Many new functions that support features including control
3513over which day of the week is the first day, returning strings instead
3514of printing them. Also new symbolic constants for days of week,
3515e.g. MONDAY, ..., SUNDAY.
3516
3517cgi -- FieldStorage objects have a getvalue method that works like a
3518dictionary's get method and returns the value attribute of the object.
3519
3520ConfigParser -- The parser object has new methods has_option,
3521remove_section, remove_option, set, and write. They allow the module
3522to be used for writing config files as well as reading them.
3523
3524ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003525optionally support the RFC 959 REST command.
3526
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003527gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003528
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003529httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3530the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003531
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003532locale -- implement getdefaultlocale for Win32 and Macintosh
3533
3534marshal -- no longer dumps core when marshaling deeply nested or
3535recursive data structures
3536
3537os -- new functions isatty, seteuid, setegid, setreuid, setregid
3538
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003539os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3540support under Unix.
3541
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003542os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003543
3544os.path -- fix semantics of os.path.commonprefix
3545
3546smtplib -- support for sending very long messages
3547
3548socket -- new function getfqdn()
3549
3550readline -- new functions to read, write and truncate history files.
3551The readline section of the library reference manual contains an
3552example.
3553
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003554select -- add interface to poll system call
3555
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003556shutil -- new copyfileobj function
3557
3558SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3559HTTP server.
3560
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003561Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003562
3563urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003564e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003565
3566whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003567
3568
3569Obsolete Modules
3570----------------
3571
3572None. However note that 1.6 made a whole slew of modules obsolete:
3573stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3574poly, zmod, strop, util, whatsound.
3575
3576
3577Changed, New, Obsolete Tools
3578----------------------------
3579
Tim Peters8b092332000-09-05 20:15:25 +00003580None.
Guido van Rossume905e952000-09-05 12:42:46 +00003581
3582
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003583C-level Changes
3584---------------
3585
3586Several cleanup jobs were carried out throughout the source code.
3587
3588All C code was converted to ANSI C; we got rid of all uses of the
3589Py_PROTO() macro, which makes the header files a lot more readable.
3590
3591Most of the portability hacks were moved to a new header file,
3592pyport.h; several other new header files were added and some old
3593header files were removed, in an attempt to create a more rational set
3594of header files. (Few of these ever need to be included explicitly;
3595they are all included by Python.h.)
3596
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003597Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003598and Win64, especially for the new Intel Itanium processor. Mick also
3599added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003600
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003601The C APIs to return an object's size have been update to consistently
3602use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3603previous versions, the abstract interfaces used PyXXX_Length and the
3604concrete interfaces used PyXXX_Size. The old names,
3605e.g. PyObject_Length, are still available for backwards compatibility
3606at the API level, but are deprecated.
3607
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003608The PyOS_CheckStack function has been implemented on Windows by
3609Fredrik Lundh. It prevents Python from failing with a stack overflow
3610on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003611
3612The GC changes resulted in creation of two new slots on object,
3613tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003614the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003615
3616The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003617C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003618
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003619PyErr_Format has been updated to automatically calculate the size of
3620the buffer needed to hold the formatted result string. This change
3621prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003622
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003623New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003624
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003625PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3626that are the same as their non-Ex counterparts except they take an
3627extra flag argument that tells them to close the file when done.
3628
3629XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003630
Tim Peters8b092332000-09-05 20:15:25 +00003631
3632Windows Changes
3633---------------
3634
3635New popen2/popen3/peopen4 in os module (see Changed Modules above).
3636
3637os.popen is much more usable on Windows 95 and 98. See Microsoft
3638Knowledge Base article Q150956. The Win9x workaround described there
3639is implemented by the new w9xpopen.exe helper in the root of your
3640Python installation. Note that Python uses this internally; it is not
3641a standalone program.
3642
3643Administrator privileges are no longer required to install Python
3644on Windows NT or Windows 2000. If you have administrator privileges,
3645Python's registry info will be written under HKEY_LOCAL_MACHINE.
3646Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003647under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003648uses of Python, but will prevent some advanced uses from working
3649(for example, running a Python script as an NT service, or possibly
3650from CGI).
3651
3652[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3653installer; instead, it installs the needed Tcl/Tk files directly in the
3654Python directory. If you already have a Tcl/Tk installation, this
3655wastes some disk space (about 4 Megs) but avoids problems with
3656conflicting Tcl/Tk installations, and makes it much easier for Python
3657to ensure that Tcl/Tk can find all its files.
3658
3659[This was new in 1.6] The Windows installer now installs by default in
3660\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3661
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003662
3663Updates to the changes between 1.5.2 and 1.6
3664--------------------------------------------
3665
3666The 1.6 NEWS file can't be changed after the release is done, so here
3667is some late-breaking news:
3668
3669New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3670and changes to getlocale() and setlocale().
3671
3672The new module is now enabled per default.
3673
3674It is not true that the encodings codecs cannot be used for normal
3675strings: the string.encode() (which is also present on 8-bit strings
3676!) allows using them for 8-bit strings too, e.g. to convert files from
3677cp1252 (Windows) to latin-1 or vice-versa.
3678
3679Japanese codecs are available from Tamito KAJIYAMA:
3680http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3681
3682
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003683======================================================================