blob: 3c5c8348207c071a423efff5351317ad6aa94c11 [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 Rossumb57089c2002-08-06 16:20:26 +00009- File objects are now their own iterators. For a file f, iter(f) now
10 returns f (unless f is closed), and f.next() is similar to
11 f.readline() when EOF is not reached; however, f.next() uses a
12 readahead buffer that messes up the file position, so mixing
13 f.next() and f.readline() (or other methods) doesn't work right.
14 Calling f.seek() drops the readahead buffer, but other operations
15 don't. It so happens that this gives a nice additional speed boost
16 to "for line in file:"; the xreadlines method and corresponding
17 module are now obsolete.
18
Guido van Rossumde392d32002-08-05 14:17:20 +000019- Encoding declarations (PEP 263, phase 1) have been implemented. A
20 comment of the form "# -*- coding: <encodingname> -*-" in the first
21 or second line of a Python source file indicates the encoding.
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +000022
Tim Petersf47630f2002-08-01 02:34:51 +000023- list.sort() has a new implementation. While cross-platform results
24 may vary, and in data-dependent ways, this is much faster on many
25 kinds of partially ordered lists than the previous implementation,
26 and reported to be just as fast on randomly ordered lists on
27 several major platforms. This sort is also stable (if A==B and A
28 precedes B in the list at the start, A precedes B after the sort too),
29 although the language definition does not guarantee stability. A
30 potential drawback is that list.sort() may require temp space of
31 len(list)*2 bytes (*4 on a 64-bit machine). It's therefore possible
32 for list.sort() to raise MemoryError now, even if a comparison function
33 does not. See <http://www.python.org/sf/587076> for full details.
34
Guido van Rossum2d5389c2002-07-23 03:44:35 +000035- All standard iterators now ensure that, once StopIteration has been
36 raised, all future calls to next() on the same iterator will also
37 raise StopIteration. There used to be various counterexamples to
38 this behavior, which could caused confusion or subtle program
39 breakage, without any benefits. (Note that this is still an
40 iterator's responsibility; the iterator framework does not enforce
41 this.)
42
Mark Hammondc0e35152002-07-16 01:32:30 +000043- Ctrl+C handling on Windows has been made more consistent with
44 other platforms. KeyboardInterrupt can now reliably be caught,
Tim Petersf47630f2002-08-01 02:34:51 +000045 and Ctrl+C at an interative prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +000046 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Petersf47630f2002-08-01 02:34:51 +000047 interrupt time.sleep() in the main thread, and any child processes
48 created via the popen family are also interrupted (as generally
Mark Hammondc0e35152002-07-16 01:32:30 +000049 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
50
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000051- Slices and repetitions of buffer objects now consistently return
52 a string. Formerly, strings would be returned most of the time,
53 but a buffer object would be returned when the repetition count
54 was one or when the slice range was all inclusive.
55
Guido van Rossumc7c36502002-06-21 01:29:25 +000056- The __slots__ variable can now mention "private" names, and the
57 right thing will happen (e.g. __slots__ = ["__foo"]).
58
Walter Dörwald3430d702002-06-17 10:43:59 +000059- Unicode objects in sys.path are no longer ignored but treated
60 as directory names.
61
Guido van Rossum9562bcf2002-06-14 21:31:18 +000062- The built-ins slice() and buffer() are now callable types. The
63 types classobj (formerly class), code, function, instance, and
64 instancemethod (formerly instance-method), which have no built-in
65 names but are accessible through the types module, are now also
66 callable. The type dict-proxy is renamed to dictproxy.
67
Neal Norwitz1f68fc72002-06-14 00:50:42 +000068- Fixed string.startswith and string.endswith builtin methods
69 so they accept negative indices. [SF bug 493951]
70
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000071- Fixed a bug with a continue inside a try block and a yield in the
72 finally clause. [SF bug 567538]
73
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000074- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000075 with a third "stride" parameter. For example, "hello world"[::-1]
76 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000077
Guido van Rossum9f7549b2002-06-10 21:39:42 +000078- Cycles going through the __class__ link of a new-style instance are
79 now detected by the garbage collector.
80
Guido van Rossum9923ffe2002-06-04 19:52:53 +000081- Classes using __slots__ are now properly garbage collected.
82 [SF bug 519621]
83
84- Tightened the __slots__ rules: a slot name must be a valid Python
85 identifier.
86
Guido van Rossum2e4e0262002-06-04 05:58:34 +000087- The constructor for the module type now requires a name argument and
88 takes an optional docstring argument. Previously, this constructor
89 ignored its arguments. As a consequence, deriving a class from a
90 module (not from the module type) is now illegal; previously this
91 created an unnamed module, just like invoking the module type did.
92 [SF bug 563060]
93
Neal Norwitzd68f5172002-05-29 15:54:55 +000094- A new warning PendingDeprecationWarning was added to provide
95 direction on features which are in the process of being deprecated.
96 The warning will not be printed by default. To see the pending
97 deprecations, use -Walways::PendingDeprecationWarning::
98 as a command line option or warnings.filterwarnings() in code.
99
Neal Norwitz32a7e7f2002-05-31 19:58:02 +0000100- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +0000101 for 'str' and 'unicode', and can be used instead of
102 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +0000103 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +0000104 is an abstract base class and cannot be instantiated directly.
105
Fred Draked0ba6362002-05-02 21:28:26 +0000106- Deprecated features of xrange objects have been removed as
107 promised. The start, stop, and step attributes and the tolist()
108 method no longer exist. xrange repetition and slicing have been
109 removed.
110
Guido van Rossum7dab2422002-04-26 19:40:56 +0000111- New builtin function enumerate(x), from PEP 279. Example:
112 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
113 The argument can be an arbitrary iterable object.
114
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000115- The assert statement no longer tests __debug__ at runtime. This means
116 that assert statements cannot be disabled by assigning a false value
117 to __debug__.
118
Walter Dörwald068325e2002-04-15 13:36:47 +0000119- A method zfill() was added to str and unicode, that fills a numeric
120 string to the left with zeros. For example,
121 "+123".zfill(6) -> "+00123".
122
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000123- Complex numbers supported divmod() and the // and % operators, but
124 these make no sense. Since this was documented, they're being
125 deprecated now.
126
Guido van Rossum26dd8302002-04-26 20:11:29 +0000127- String and unicode methods lstrip(), rstrip() and strip() now take
128 an optional argument that specifies the characters to strip. For
129 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000130
Guido van Rossumc69343b2002-04-12 19:22:48 +0000131- Added a new dict method pop(key). This removes and returns the
132 value corresponding to key. [SF patch #539949]
133
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000134- Changed new-style class instantiation so that when C's __new__
135 method returns something that's not a C instance, its __init__ is
136 not called. [SF bug #537450]
137
Guido van Rossum181e41a2002-04-06 00:23:25 +0000138- Fixed super() to work correctly with class methods. [SF bug #535444]
139
Guido van Rossum47834462002-04-04 15:21:33 +0000140- A new built-in type, bool, has been added, as well as built-in
141 names for its two values, True and False. Comparisons and sundry
142 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000143 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000144 is backward compatible.
145
Guido van Rossum95b62a62002-03-29 01:07:24 +0000146- Fixed two bugs reported as SF #535905: under certain conditions,
147 deallocating a deeply nested structure could cause a segfault in the
148 garbage collector, due to interaction with the "trashcan" code;
149 access to the current frame during destruction of a local variable
150 could access a pointer to freed memory.
151
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000152- The optional object allocator ("pymalloc") has been enabled by
153 default. The recommended practice for memory allocation and
154 deallocation has been streamlined. A header file is included,
155 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
156 and lets them use the same API with Python versions from 1.5.2
157 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000158
Guido van Rossum8c842552002-03-14 23:05:54 +0000159- If you try to pickle an instance of a class that has __slots__ but
160 doesn't define or override __getstate__, a TypeError is now raised.
161 This is done by adding a bozo __getstate__ to the class that always
162 raises TypeError. (Before, this would appear to be pickled, but the
163 state of the slots would be lost.)
164
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000165- PyErr_Display will provide file and line information for all exceptions
166 that have an attribute print_file_and_line, not just SyntaxErrors.
167
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000168- The UTF-8 codec will now encode and decode Unicode surrogates
169 correctly and without raising exceptions for unpaired ones.
170
Neal Norwitz649b7592002-01-01 19:07:13 +0000171- file.xreadlines() now raises a ValueError if the file is closed:
172 Previously, an xreadlines object was returned which would raise
173 a ValueError when the xreadlines.next() method was called.
174
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000175- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000176 An exception will now be raised if more than one argument is used.
177
Tim Petersaf8446f2001-12-21 21:36:50 +0000178Extension modules
179
Guido van Rossumb57089c2002-08-06 16:20:26 +0000180- The xreadlines module is slated for obsolescence.
181
Guido van Rossum79f0a102002-07-23 03:32:08 +0000182- The strptime function in the time module is now always available (a
183 Python implementation is used when the C library doesn't define it).
184
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000185- The 'new' module is no longer an extension, but a Python module that
186 only exists for backwards compatibility. Its contents are no longer
187 functions but callable type objects.
188
Tim Peters81b92512002-04-29 01:37:32 +0000189- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000190 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000191 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000192
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000193- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
194 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000195
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000196- The locale module now exposes the C library's gettext interface.
197
Tim Petersfbf74f22002-03-14 19:06:01 +0000198- A security hole ("double free") was found in zlib-1.1.3, a popular
199 third party compression library used by some Python modules. The
200 hole was quickly plugged in zlib-1.1.4, and the Windows build of
201 Python now ships with zlib-1.1.4.
202
Martin v. Löwis688357e2002-04-08 21:28:20 +0000203- pwd, grp, and resource return enhanced tuples now, with symbolic
204 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000205
Martin v. Löwis99866332002-03-01 10:27:01 +0000206- array.array is now a type object. A new format character
207 'u' indicates Py_UNICODE arrays. For those, .tounicode and
208 .fromunicode methods are available. Arrays now support __iadd__
209 and __imul__.
210
Neal Norwitze790eae2002-01-01 21:14:12 +0000211- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000212 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
213 is called.
214
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000215- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
216 been added where available.
217
Tim Petersaf8446f2001-12-21 21:36:50 +0000218Library
219
Guido van Rossum4a57c332002-08-02 18:05:20 +0000220- New "algorithms" module: heapq, implements a heap queue. Thanks to
221 Kevin O'Connor for the code and François Pinard for an entertaining
222 write-up explaining the theory and practical uses of heaps.
223
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000224- New encoding for the Palm OS character set: palmos.
225
Tim Peters943382c2002-07-07 03:59:34 +0000226- binascii.crc32() and the zipfile module had problems on some 64-bit
227 platforms. These have been fixed. On a platform with 8-byte C longs,
228 crc32() now returns a signed-extended 4-byte result, so that its value
229 as a Python int is equal to the value computed a 32-bit platform.
230
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000231- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
232 argument.
233
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000234- Some fixes in the copy module: when an object is copied through its
235 __reduce__ method, there was no check for a __setstate__ method on
236 the result [SF patch 565085]; deepcopy should treat instances of
237 custom metaclasses the same way it treats instances of type 'type'
238 [SF patch 560794].
239
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000240- Sockets now support timeout mode. After s.settimeout(T), where T is
241 a float expressing seconds, subsequent operations raise an exception
242 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000243 mode, use s.settimeout(None). There's also a module function,
244 socket.setdefaulttimeout(T), which sets the default for all sockets
245 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000246
247- getopt.gnu_getopt was added. This supports GNU-style option
248 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000249
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000250- Stop using strings for exceptions. String objects used for
251 exceptions are now classes deriving from Exception. The objects
252 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
253 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000254
Walter Dörwald474458d2002-06-04 15:16:29 +0000255- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
256 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
257 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
258 big endian systems were added to the codecs module. The old names
259 BOM32_* and BOM64_* were off by a factor of 2.
260
Guido van Rossumf9257822002-06-18 20:43:18 +0000261- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000262
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000263- ftplib.retrlines() now tests for callback is None rather than testing
264 for False. Was causing an error when given a callback object which
265 was callable but also returned len() as zero. The change may
266 create new breakage if the caller relied on the undocumented behavior
267 and called with callback set to [] or some other False value not
268 identical to None.
269
Tim Peters46c04e12002-05-05 20:40:00 +0000270- random.gauss() uses a piece of hidden state used by nothing else,
271 and the .seed() and .whseed() methods failed to reset it. In other
272 words, setting the seed didn't completely determine the sequence of
273 results produced by random.gauss(). It does now. Programs repeatedly
274 mixing calls to a seed method with calls to gauss() may see different
275 results now.
276
Fred Drake7f781c92002-05-01 20:33:53 +0000277- The pickle.Pickler class grew a clear_memo() method to mimic that
278 provided by cPickle.Pickler.
279
Tim Peters81b92512002-04-29 01:37:32 +0000280- difflib's SequenceMatcher class now does a dynamic analysis of
281 which elements are so frequent as to constitute noise. For
282 comparing files as sequences of lines, this generally works better
283 than the IS_LINE_JUNK function, and function ndiff's linejunk
284 argument defaults to None now as a result. A happy benefit is
285 that SequenceMatcher may run much faster now when applied
286 to large files with many duplicate lines (for example, C program
287 text with lots of repeated "}" and "return NULL;" lines).
288
Guido van Rossum256705b2002-04-23 13:29:43 +0000289- New Text.dump() method in Tkinter module.
290
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000291- New distutils commands for building packagers were added to
292 support pkgtool on Solaris and swinstall on HP-UX.
293
294- distutils now has a new abstract binary packager base class
295 command/bdist_packager, which simplifies writing packagers.
296 This will hopefully provide the missing bits to encourage
297 people to submit more packagers, e.g. for Debian, FreeBSD
298 and other systems.
299
Guido van Rossumf9257822002-06-18 20:43:18 +0000300- The UTF-16, -LE and -BE stream readers now raise a
301 NotImplementedError for all calls to .readline(). Previously, they
302 used to just produce garbage or fail with an encoding error --
303 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 +0000304 work well with these.
305
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000306- compileall now supports quiet operation.
307
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000308- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000309 connections.
310
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000311- socket module: the SSL support was broken out of the main
312 _socket module C helper and placed into a new _ssl helper
313 which now gets imported by socket.py if available and working.
314
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000315- encodings package: added aliases for all supported IANA character
316 sets
317
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000318- ftplib: to safeguard the user's privacy, anonymous login will use
319 "anonymous@" as default password, rather than the real user and host
320 name.
321
Fred Drake36736122002-01-10 13:50:31 +0000322- webbrowser: tightened up the command passed to os.system() so that
323 arbitrary shell code can't be executed because a bogus URL was
324 passed in.
325
Tim Peters11bd9942002-02-01 00:52:29 +0000326- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000327 gettext.find an optional all argument. Translations will now fallback
328 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000329
Martin v. Löwis9668b932002-01-12 11:27:42 +0000330- distutils bdist commands now offer a --skip-build option.
331
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000332- warnings.warn now accepts a Warning instance as first argument.
333
Fred Drakefed7e852002-04-04 19:36:15 +0000334- The xml.sax.expatreader.ExpatParser class will no longer create
335 circular references by using itself as the locator that gets passed
336 to the content handler implementation. [SF bug #535474]
337
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000338- The email.Parser.Parser class now properly parses strings regardless
339 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
340 or CRLF). Also, the Header class's constructor default arguments
341 has changed slightly so that an explicit maxlinelen value is always
342 honored.
343
Tim Petersaf8446f2001-12-21 21:36:50 +0000344Tools/Demos
345
Fred Drake40813b12002-08-05 15:24:19 +0000346- IDLE supports the new encoding declarations (PEP 263); it can also
347 deal with legacy 8-bit files if they use the locale's encoding. It
348 allows non-ASCII strings in the interactive shell and executes them
349 in the locale's encoding.
Martin v. Löwis98ce7b72002-08-05 15:11:26 +0000350
Marc-André Lemburg46260092002-04-04 16:17:11 +0000351- freeze.py now produces binaries which can import shared modules,
352 unlike before when this failed due to missing symbol exports in
353 the generated binary.
354
Tim Petersaf8446f2001-12-21 21:36:50 +0000355Build
356
Tim Petersf47630f2002-08-01 02:34:51 +0000357- The public Python C API will generally be declared using PyAPI_FUNC
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000358 and PyAPI_DATA macros, while Python extension module init functions
359 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
360 are deprecated.
361
Tim Petersc6a3ff62002-07-08 22:11:52 +0000362- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
363 get into infinite loops, when a new-style class got garbage-collected.
364 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
365 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
366 COUNT_ALLOCS is not enabled by default, in either release or debug
367 builds, and that new-style classes are immortal only in COUNT_ALLOCS
368 builds.
369
Tim Peters943382c2002-07-07 03:59:34 +0000370- Compiling out the cyclic garbage collector is no longer an option.
371 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
372 that it's always defined (for the benefit of any extension modules
373 that may be conditionalizing on it). A bonus is that any extension
374 type participating in cyclic gc can choose to participate in the
375 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
376 to require editing the core to teach the trashcan mechanism about the
377 new type.
378
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000379- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000380
381 The Standard C macro HUGE_VAL and its float and long double analogs,
382 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
383 positive infinities.
384
385 Python only uses the double HUGE_VAL, and only to #define its own symbol
386 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
387 pyport.h used to try to worm around that, but the workarounds triggered
388 other bugs on other platforms, so we gave up. If your platform defines
389 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
390 that works on your platform. The only instance of this I'm sure about
391 is on an unknown subset of Cray systems, described here:
392
393 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
394
395 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
396
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000397- The configure option --without-doc-strings can be used to remove the
398 doc strings from the builtin functions and modules; this reduces the
399 size of the executable.
400
Tim Peters639295f2002-04-21 07:30:30 +0000401- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
402 say how or when to configure it, or how to turn it off.
403
Martin v. Löwis1142de32002-03-29 16:28:31 +0000404- On Unix, a shared libpython2.3.so can be created with --enable-shared.
405
Tim Peters8deda702002-03-30 10:06:07 +0000406- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
407 preprocessor symbols were eliminated. The internal decisions they
408 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000409
Fred Drake7d28b732002-05-02 21:17:00 +0000410- The tools used to build the documentation now work under Cygwin as
411 well as Unix.
412
Skip Montanaro57454e52002-06-14 20:30:31 +0000413- The bsddb and dbm module builds have been changed to try and avoid version
414 skew problems and disable linkage with Berkeley DB 1.85 unless the
415 installer knows what s/he's doing. See the section on building these
416 modules in the README file for details.
417
Tim Petersaf8446f2001-12-21 21:36:50 +0000418C API
419
Thomas Heller085358a2002-07-29 14:27:41 +0000420- New functions PyErr_SetExcFromWindowsErr() and
421 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
422 PyErr_SetFromWindowsErrWithFilename() and
423 PyErr_SetFromWindowsErr(), but they allow to specify
424 the exception type to raise. Available on Windows.
425
Tim Peters7c321a82002-07-09 02:57:01 +0000426- Py_FatalError() is now declared as taking a const char* argument. It
427 was previously declared without const. This should not affect working
428 code.
429
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000430- Added new macro PySequence_ITEM(o, i) that directly calls
431 sq_item without rechecking that o is a sequence and without
432 adjusting for negative indices.
433
Fred Draked0ba6362002-05-02 21:28:26 +0000434- PyRange_New() now raises ValueError if the fourth argument is not 1.
435 This is part of the removal of deprecated features of the xrange
436 object.
437
Guido van Rossum517c7d42002-04-26 02:49:14 +0000438- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
439 coercion if both arguments have the same type but this type has the
440 CHECKTYPES flag set. This is to better support proxies.
441
Neil Schemenauer9344b142002-04-12 23:00:08 +0000442- The type of tp_free has been changed from "void (*)(PyObject *)" to
443 "void (*)(void *)".
444
445- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
446
Guido van Rossum0986d822002-04-08 01:38:42 +0000447- A type can now inherit its metatype from its base type. Previously,
448 when PyType_Ready() was called, if ob_type was found to be NULL, it
449 was always set to &PyType_Type; now it is set to base->ob_type,
450 where base is tp_base, defaulting to &PyObject_Type.
451
452- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
453
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000454- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000455
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000456- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000457 without going through the buffer API.
458
Martin v. Löwis7198a522002-01-01 19:59:11 +0000459- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
460
Tim Peters10a3bb52001-12-25 19:07:38 +0000461- An old #define of ANY as void has been removed from pyport.h. This
462 hasn't been used since Python's pre-ANSI days, and the #define has
463 been marked as obsolete since then. SF bug 495548 says it created
464 conflicts with other packages, so keeping it around wasn't harmless.
465
Tim Petersaf8446f2001-12-21 21:36:50 +0000466- Because Python's magic number scheme broke on January 1st, we decided
467 to stop Python development. Thanks for all the fish!
468
Tim Petersfb05db22002-03-11 00:24:00 +0000469- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000470 scheme to a new one. See Python/import.c for details.
471
Tim Petersaf8446f2001-12-21 21:36:50 +0000472New platforms
473
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000474- AtheOS is now supported.
475
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000476- the EMX runtime environment on OS/2 is now supported.
477
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000478- GNU/Hurd is now supported.
479
Tim Petersaf8446f2001-12-21 21:36:50 +0000480Tests
481
482Windows
483
Tim Peters08e72952002-04-16 20:48:01 +0000484- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
485 of that has been fixed in the installer (disabled Wise's "delete in-
486 use files" uninstall option).
487
Guido van Rossum181e41a2002-04-06 00:23:25 +0000488- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
489
Tim Peters33187922002-04-04 20:02:04 +0000490- The installer now installs Start menu shortcuts under (the local
491 equivalent of) "All Users" when doing an Admin install.
492
Tim Petersfb05db22002-03-11 00:24:00 +0000493- file.truncate([newsize]) now works on Windows for all newsize values.
494 It used to fail if newsize didn't fit in 32 bits, reflecting a
495 limitation of MS _chsize (which is no longer used).
496
Tim Petersab034fa2002-02-01 11:27:43 +0000497- os.waitpid() is now implemented for Windows, and can be used to block
498 until a specified process exits. This is similar to, but not exactly
499 the same as, os.waitpid() on POSIX systems. If you're waiting for
500 a specific process whose pid was obtained from one of the spawn()
501 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000502 See the docs for details. The docs were changed to clarify that
503 spawn functions return, and waitpid requires, a process handle on
504 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000505
Tim Peters11bd9942002-02-01 00:52:29 +0000506- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000507 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000508 to a nasty problem: before 2.3, if you got a temp file on Windows, it
509 got wrapped in an object whose close() method first closed the
510 underlying file, then deleted the file. This usually worked fine.
511 However, the spawn family of functions on Windows create (at a low C
512 level) the same set of open files in the spawned process Q as were
513 open in the spawning process P. If a temp file f was among them, then
514 doing f.close() in P first closed P's C-level file handle on f, but Q's
515 C-level file handle on f remained open, so the attempt in P to delete f
516 blew up with a "Permission denied" error (Windows doesn't allow
517 deleting open files). This was surprising, subtle, and difficult to
518 work around.
519
520- The os module now exports all the symbolic constants usable with the
521 low-level os.open() on Windows: the new constants in 2.3 are
522 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
523 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
524 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
525 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
526 (so specify both if you want both; note that neither is useful unless
527 specified with O_CREAT too).
528
Tim Petersaf8446f2001-12-21 21:36:50 +0000529Mac
530
531
Tim Peters909c0912001-12-14 23:16:18 +0000532What's New in Python 2.2 final?
533Release date: 21-Dec-2001
534===============================
535
536Type/class unification and new-style classes
537
Barry Warsaw52acb492001-12-21 20:04:22 +0000538- pickle.py, cPickle: allow pickling instances of new-style classes
539 with a custom metaclass.
540
Tim Peters909c0912001-12-14 23:16:18 +0000541Core and builtins
542
Barry Warsaw52acb492001-12-21 20:04:22 +0000543- weakref proxy object: when comparing, unwrap both arguments if both
544 are proxies.
545
Tim Peters909c0912001-12-14 23:16:18 +0000546Extension modules
547
Barry Warsaw52acb492001-12-21 20:04:22 +0000548- binascii.b2a_base64(): fix a potential buffer overrun when encoding
549 very short strings.
550
551- cPickle: the obscure "fast" mode was suspected of causing stack
552 overflows on the Mac. Hopefully fixed this by setting the recursion
553 limit much smaller. If the limit is too low (it only affects
554 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
555 when compiling cPickle.c (or in pyconfig.h).
556
Tim Peters909c0912001-12-14 23:16:18 +0000557Library
558
Barry Warsaw52acb492001-12-21 20:04:22 +0000559- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
560 close or delete time).
561
562- rfc822.py: fixed a bug where the address '<>' was converted to None
563 instead of an empty string (also fixes the email.Utils module).
564
565- xmlrpclib.py: version 1.0.0; uses precision for doubles.
566
567- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000568 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000569
Tim Peters909c0912001-12-14 23:16:18 +0000570Tools/Demos
571
572Build
573
574C API
575
576New platforms
577
578Tests
579
580Windows
581
Barry Warsaw52acb492001-12-21 20:04:22 +0000582- distutils package: fixed broken Windows installers (bdist_wininst).
583
584- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
585 instances are deleted at process exit time.
586
587- socket.py: prevent mysterious warnings when socket instances are
588 deleted at process exit time.
589
590- posixmodule.c: fix a Windows crash with stat() of a filename ending
591 in backslash.
592
Tim Peters909c0912001-12-14 23:16:18 +0000593Mac
594
Barry Warsaw52acb492001-12-21 20:04:22 +0000595- The Carbon toolbox modules have been upgraded to Universal Headers
596 3.4, and experimental CoreGraphics and CarbonEvents modules have
597 been added. All only for framework-enabled MacOSX.
598
Tim Peters909c0912001-12-14 23:16:18 +0000599
Tim Peters6272dfd2001-12-13 19:34:00 +0000600What's New in Python 2.2c1?
601Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000602===========================
603
604Type/class unification and new-style classes
605
Barry Warsaw06557452001-12-14 20:47:12 +0000606- Guido's tutorial introduction to the new type/class features has
607 been extensively updated. See
608
609 http://www.python.org/2.2/descrintro.html
610
611 That remains the primary documentation in this area.
612
Guido van Rossum33bab012001-12-05 22:45:48 +0000613- Fixed a leak: instance variables declared with __slots__ were never
614 deleted!
615
Guido van Rossum4b800852001-12-03 00:54:52 +0000616- The "delete attribute" method of descriptor objects is called
617 __delete__, not __del__. In previous releases, it was mistakenly
618 called __del__, which created an unfortunate overloading condition
619 with finalizers. (The "get attribute" and "set attribute" methods
620 are still called __get__ and __set__, respectively.)
621
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000622- Some subtle issues with the super built-in were fixed:
623
624 (a) When super itself is subclassed, its __get__ method would still
625 return an instance of the base class (i.e., of super).
626
627 (b) super(C, C()).__class__ would return C rather than super. This
628 is confusing. To fix this, I decided to change the semantics of
629 super so that it only applies to code attributes, not to data
630 attributes. After all, overriding data attributes is not
631 supported anyway.
632
633 (c) The __get__ method didn't check whether the argument was an
634 instance of the type used in creation of the super instance.
635
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000636- Previously, hash() of an instance of a subclass of a mutable type
637 (list or dictionary) would return some value, rather than raising
638 TypeError. This has been fixed. Also, directly calling
639 dict.__hash__ and list.__hash__ now raises the same TypeError
640 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000641
Guido van Rossumd331cb52001-12-05 19:46:42 +0000642- New-style objects now support deleting their __dict__. This is for
643 all intents and purposes equivalent to assigning a brand new empty
644 dictionary, but saves space if the object is not used further.
645
Tim Petersb3c9af12001-11-17 00:21:57 +0000646Core and builtins
647
Tim Peters3caca232001-12-06 06:23:26 +0000648- -Qnew now works as documented in PEP 238: when -Qnew is passed on
649 the command line, all occurrences of "/" use true division instead
650 of classic division. See the PEP for details. Note that "all"
651 means all instances in library and 3rd-party modules, as well as in
652 your own code. As the PEP says, -Qnew is intended for use only in
653 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000654 Note that test_coercion.py in the standard Python test suite fails
655 under -Qnew; this is expected, and won't be repaired until true
656 division becomes the default (in the meantime, test_coercion is
657 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000658
Fred Drake6c01e252001-12-14 17:08:12 +0000659- complex() now only allows the first argument to be a string
660 argument, and raises TypeError if either the second arg is a string
661 or if the second arg is specified when the first is a string.
662
Tim Petersb3c9af12001-11-17 00:21:57 +0000663Extension modules
664
Martin v. Löwis560da622001-11-24 09:24:51 +0000665- gc.get_referents was renamed to gc.get_referrers.
666
Tim Petersb3c9af12001-11-17 00:21:57 +0000667Library
668
Tim Peters25059d32001-12-07 20:35:43 +0000669- Functions in the os.spawn() family now release the global interpreter
670 lock around calling the platform spawn. They should always have done
671 this, but did not before 2.2c1. Multithreaded programs calling
672 an os.spawn function with P_WAIT will no longer block all Python threads
673 until the spawned program completes. It's possible that some programs
674 relies on blocking, although more likely by accident than by design.
675
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000676- webbrowser defaults to netscape.exe on OS/2 now.
677
Martin v. Löwis652e1912001-11-25 14:50:56 +0000678- Tix.ResizeHandle exposes detach_widget, hide, and show.
679
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000680- The charset alias windows_1252 has been added.
681
Barry Warsaw06557452001-12-14 20:47:12 +0000682- types.StringTypes is a tuple containing the defined string types;
683 usually this will be (str, unicode), but if Python was compiled
684 without Unicode support it will be just (str,).
685
686- The pulldom and minidom modules were synchronized to PyXML.
687
Tim Petersb3c9af12001-11-17 00:21:57 +0000688Tools/Demos
689
Barry Warsaw06557452001-12-14 20:47:12 +0000690- A new script called Tools/scripts/google.py was added, which fires
691 off a search on Google.
692
Tim Petersb3c9af12001-11-17 00:21:57 +0000693Build
694
Barry Warsaw06557452001-12-14 20:47:12 +0000695- Note that release builds of Python should arrange to define the
696 preprocessor symbol NDEBUG on the command line (or equivalent).
697 In the 2.2 pre-release series we tried to define this by magic in
698 Python.h instead, but it proved to cause problems for extension
699 authors. The Unix, Windows and Mac builds now all define NDEBUG in
700 release builds via cmdline (or equivalent) instead. Ports to
701 other platforms should do likewise.
702
Jack Jansen1999ef42001-12-06 21:47:20 +0000703- It is no longer necessary to use --with-suffix when building on a
704 case-insensitive file system (such as Mac OS X HFS+). In the build
705 directory an extension is used, but not in the installed python.
706
Tim Petersb3c9af12001-11-17 00:21:57 +0000707C API
708
Tim Petersf582b822001-12-11 18:51:08 +0000709- New function PyDict_MergeFromSeq2() exposes the builtin dict
710 constructor's logic for updating a dictionary from an iterable object
711 producing key-value pairs.
712
Tim Peterscffed4b2001-11-29 03:26:37 +0000713- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000714 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000715 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
716 dump core in some bad cases. This has been repaired. As a result,
717 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
718 previously went unchallenged.
719
Tim Petersb3c9af12001-11-17 00:21:57 +0000720New platforms
721
722Tests
723
724Windows
725
726Mac
727
Jack Jansenffa260f2001-12-06 21:14:00 +0000728- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
729 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000730
Barry Warsaw06557452001-12-14 20:47:12 +0000731- Changed logic for finding python home in Mac OS X framework Pythons.
732 Now sys.executable points to the executable again, in stead of to
733 the shared library. The latter is used only for locating the python
734 home.
735
736
Tim Peters84362bc2001-10-19 17:55:30 +0000737What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000738Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000739===========================
740
741Type/class unification and new-style classes
742
Guido van Rossum3d27df02001-11-15 20:27:54 +0000743- Multiple inheritance mixing new-style and classic classes in the
744 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000745
746 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000747 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000748
749 The MRO (method resolution order) for each base class is respected
750 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000751 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000752 This needs to be documented.
753
Tim Petersa427a2b2001-10-29 22:25:45 +0000754- The new builtin dictionary() constructor, and dictionary type, have
755 been renamed to dict. This reflects a decade of common usage.
756
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000757- dict() now accepts an iterable object producing 2-sequences. For
758 example, dict(d.items()) == d for any dictionary d. The argument,
759 and the elements of the argument, can be any iterable objects.
760
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000761- New-style classes can now have a __del__ method, which is called
762 when the instance is deleted (just like for classic classes).
763
Guido van Rossum12d955c2001-10-26 14:56:06 +0000764- Assignment to object.__dict__ is now possible, for objects that are
765 instances of new-style classes that have a __dict__ (unless the base
766 class forbids it).
767
Guido van Rossumc8e56452001-10-22 00:43:43 +0000768- Methods of built-in types now properly check for keyword arguments
769 (formerly these were silently ignored). The only built-in methods
770 that take keyword arguments are __call__, __init__ and __new__.
771
Guido van Rossum86443212001-10-27 22:28:54 +0000772- The socket function has been converted to a type; see below.
773
Tim Peters84362bc2001-10-19 17:55:30 +0000774Core and builtins
775
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000776- Assignment to __debug__ raises SyntaxError at compile-time. This
777 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000778 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000779
Guido van Rossum12d955c2001-10-26 14:56:06 +0000780- Clarified the error messages for unsupported operands to an operator
781 (like 1 + '').
782
Tim Peters84362bc2001-10-19 17:55:30 +0000783Extension modules
784
Tim Peters5ebfd362001-11-13 23:11:19 +0000785- mmap has a new keyword argument, "access", allowing a uniform way for
786 both Windows and Unix users to create read-only, write-through and
787 copy-on-write memory mappings. This was previously possible only on
788 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000789 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000790 platforms. Thanks to Jay T Miller for repairing this!
791
Tim Peters169ded02001-11-03 19:57:21 +0000792- By default, the gc.garbage list now contains only those instances in
793 unreachable cycles that have __del__ methods; in 2.1 it contained all
794 instances in unreachable cycles. "Instances" here has been generalized
795 to include instances of both new-style and old-style classes.
796
Guido van Rossum12d955c2001-10-26 14:56:06 +0000797- The socket module defines a new method for socket objects,
798 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000799 send() until all data has been sent. Also, the socket function has
800 been converted to a subclassable type, like list and tuple (etc.)
801 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000802
803- Various bugfixes to the curses module. There is now a test suite
804 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000805
Guido van Rossum692adf12001-10-30 03:03:03 +0000806- binascii.b2a_base64 no longer places an arbitrary restriction of 57
807 bytes on its input.
808
Tim Peters84362bc2001-10-19 17:55:30 +0000809Library
810
Tim Peters5ebfd362001-11-13 23:11:19 +0000811- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000812 convenience function.
813
Tim Peters75335872001-11-03 19:35:43 +0000814- Symbolic group names in regular expressions must be unique. For
815 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
816 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000817 Python 2.2 detects this error at regexp compilation time;
818 previously, the error went undetected, and results were
819 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
820 pattern.subn() methods have been rewritten in C. Also, an
821 experimental function/method finditer() has been added, which works
822 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000823
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000824- Tix exposes more commands through the classes DirSelectBox,
825 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
826 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
827 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
828
Tim Peters98791af2001-10-23 01:59:54 +0000829- Traceback objects are now scanned by cyclic garbage collection, so
830 cycles created by casual use of sys.exc_info() no longer cause
831 permanent memory leaks (provided garbage collection is enabled).
832
Guido van Rossum49192142001-10-24 20:51:44 +0000833- os.extsep -- a new variable needed by the RISCOS support. It is the
834 separator used by extensions, and is '.' on all platforms except
835 RISCOS, where it is '/'. There is no need to use this variable
836 unless you have a masochistic desire to port your code to RISCOS.
837
Barry Warsaw012852b2001-11-16 16:17:27 +0000838- mimetypes.py has optional support for non-standard, but commonly
839 found types. guess_type() and guess_extension() now accept an
840 optional `strict' flag, defaulting to true, which controls whether
841 recognize non-standard types or not. A few non-standard types we
842 know about have been added. Also, when run as a script, there are
843 new -l and -e options.
844
845- statcache is now deprecated.
846
847- email.Utils.formatdate() now produces the preferred RFC 2822 style
848 dates with numeric timezones (it used to produce obsolete dates
849 hard coded to "GMT" timezone). An optional `localtime' flag is
850 added to produce dates in the local timezone, with daylight savings
851 time properly taken into account.
852
853- In pickle and cPickle, instead of masking errors in load() by
854 transforming them into SystemError, we let the original exception
855 propagate out. Also, implement support for __safe_for_unpickling__
856 in pickle, as it already was supported in cPickle.
857
Tim Peters84362bc2001-10-19 17:55:30 +0000858Tools/Demos
859
860Build
861
Barry Warsaw012852b2001-11-16 16:17:27 +0000862- The dbm module is built using libdb1 if available. The bsddb module
863 is built with libdb3 if available.
864
865- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
866
Tim Peters84362bc2001-10-19 17:55:30 +0000867C API
868
Tim Peters1fc240e2001-10-26 05:06:50 +0000869- New function PySequence_Fast_GET_SIZE() returns the size of a non-
870 NULL result from PySequence_Fast(), more quickly than calling
871 PySequence_Size().
872
Barry Warsaw012852b2001-11-16 16:17:27 +0000873- New argument unpacking function PyArg_UnpackTuple() added.
874
875- New functions PyObject_CallFunctionObjArgs() and
876 PyObject_CallMethodObjArgs() have been added to make it more
877 convenient and efficient to call functions and methods from C.
878
879- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
880 possible that this will propagate errors it didn't before.
881
882- New function PyObject_CheckReadBuffer(), which returns true if its
883 argument supports the single-segment readable buffer interface.
884
Tim Peters84362bc2001-10-19 17:55:30 +0000885New platforms
886
Guido van Rossum86443212001-10-27 22:28:54 +0000887- We've finally confirmed that this release builds on HP-UX 11.00,
888 *with* threads, and passes the test suite.
889
Tim Peters7a33d8b2001-11-05 02:51:07 +0000890- Thanks to a series of patches from Michael Muller, Python may build
891 again under OS/2 Visual Age C++.
892
Guido van Rossum49192142001-10-24 20:51:44 +0000893- Updated RISCOS port by Dietmar Schwertberger.
894
Tim Peters84362bc2001-10-19 17:55:30 +0000895Tests
896
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000897- Added a test script for the curses module. It isn't run automatically;
898 regrtest.py must be run with '-u curses' to enable it.
899
Tim Peters84362bc2001-10-19 17:55:30 +0000900Windows
901
Barry Warsaw012852b2001-11-16 16:17:27 +0000902Mac
903
904- PythonScript has been moved to unsupported and is slated to be
905 removed completely in the next release.
906
907- It should now be possible to build applets that work on both OS9 and
908 OSX.
909
910- The core is now linked with CoreServices not Carbon; as a side
911 result, default 8bit encoding on OSX is now ASCII.
912
913- Python should now build on OSX 10.1.1
914
Tim Peters84362bc2001-10-19 17:55:30 +0000915
Tim Petersabf925f2001-09-28 21:53:42 +0000916What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000917Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000918===========================
919
920Type/class unification and new-style classes
921
Guido van Rossum687ae002001-10-15 22:03:32 +0000922- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000923 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000924 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000925 remains: the __dict__ of a new-style class is a read-only proxy; you
926 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000927 __defined__ attribute of new-style types no longer exists, for lack
928 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000929 future a __cache__ may be resurrected with a similar function, if I
930 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000931
Tim Peters1c9ca872001-10-04 06:43:12 +0000932- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
933 always returned None, even when there was a class docstring).
934
935- doctest now finds and runs docstrings attached to new-style classes,
936 class methods, static methods, and properties.
937
Guido van Rossum9074ef62001-10-16 21:34:49 +0000938Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000939
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000940- A very subtle syntactical pitfall in list comprehensions was fixed.
941 For example: [a+b for a in 'abc', for b in 'def']. The comma in
942 this example is a mistake. Previously, this would silently let 'a'
943 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
944 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
945 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
946 Note that [a for a in <singleton>] is a convoluted way to say
947 [<singleton>] anyway, so it's not like any expressiveness is lost.
948
Guido van Rossum9074ef62001-10-16 21:34:49 +0000949- getattr(obj, name, default) now only catches AttributeError, as
950 documented, rather than returning the default value for all
951 exceptions (which could mask bugs in a __getattr__ hook, for
952 example).
953
Fred Drakecb7a6b52001-10-22 18:41:51 +0000954- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000955 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000956 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000957 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000958
Guido van Rossum1c486092001-10-19 02:05:35 +0000959- unicode(obj) now behaves more like str(obj), accepting arbitrary
960 objects, and calling a __unicode__ method if it exists.
961 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000962 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000963
Barry Warsawf6fb1712001-10-19 05:35:40 +0000964- isinstance() now allows any object as the first argument and a
965 class, a type or something with a __bases__ tuple attribute for the
966 second argument. The second argument may also be a tuple of a
967 class, type, or something with __bases__, in which case isinstance()
968 will return true if the first argument is an instance of any of the
969 things contained in the second argument tuple. E.g.
970
971 isinstance(x, (A, B))
972
973 returns true if x is an instance of A or B.
974
Guido van Rossum9074ef62001-10-16 21:34:49 +0000975Extension modules
976
977- thread.start_new_thread() now returns the thread ID (previously None).
978
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000979- binascii has now two quopri support functions, a2b_qp and b2a_qp.
980
Guido van Rossumc524d952001-10-19 01:31:59 +0000981- readline now supports setting the startup_hook and the
982 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000983
Guido van Rossumc524d952001-10-19 01:31:59 +0000984- os and posix supports chroot(), setgroups() and unsetenv() where
985 available. The stat(), fstat(), statvfs() and fstatvfs() functions
986 now return "pseudo-sequences" -- the various fields can now be
987 accessed as attributes (e.g. os.stat("/").st_mtime) but for
988 backwards compatibility they also behave as a fixed-length sequence.
989 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000990 attributes.
991
992- time: localtime(), gmtime() and strptime() now return a
993 pseudo-sequence similar to the os.stat() return value, with
994 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000995
Guido van Rossum9074ef62001-10-16 21:34:49 +0000996- Decompression objects in the zlib module now accept an optional
997 second parameter to decompress() that specifies the maximum amount
998 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000999
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001000- optional SSL support in the socket module now exports OpenSSL
1001 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
1002 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +00001003 automatically seed its PRNG. Also, the keyfile and certfile
1004 arguments to socket.ssl() are now optional.
1005
1006- posixmodule (and by extension, the os module on POSIX platforms) now
1007 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001008
Guido van Rossum9074ef62001-10-16 21:34:49 +00001009Library
Guido van Rossum3c288632001-10-16 21:13:49 +00001010
Tim Peters7402f792001-10-02 03:53:41 +00001011- doctest now excludes functions and classes not defined by the module
1012 being tested, thanks to Tim Hochberg.
1013
Fred Drakecb7a6b52001-10-22 18:41:51 +00001014- HotShot, a new profiler implemented using a C-based callback, has
1015 been added. This substantially reduces the overhead of profiling,
1016 but it is still quite preliminary. Support modules and
1017 documentation will be added in upcoming releases (before 2.2 final).
1018
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001019- profile now produces correct output in situations where an exception
1020 raised in Python is cleared by C code (e.g. hasattr()). This used
1021 to cause wrong output, including spurious claims of recursive
1022 functions and attribution of time spent to the wrong function.
1023
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001024 The code and documentation for the derived OldProfile and HotProfile
1025 profiling classes was removed. The code hasn't worked for years (if
1026 you tried to use them, they raised exceptions). OldProfile
1027 intended to reproduce the behavior of the profiler Python used more
1028 than 7 years ago, and isn't interesting anymore. HotProfile intended
1029 to provide a faster profiler (but producing less information), and
1030 that's a worthy goal we intend to meet via a different approach (but
1031 without losing information).
1032
Tim Peterscce092d2001-10-09 05:31:56 +00001033- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001034 a much better system-specific calibration constant. The constant can
1035 now be specified in an instance constructor, or as a Profile class or
1036 instance variable, instead of by editing profile.py's source code.
1037 Calibration must still be done manually (see the docs for the profile
1038 module).
1039
1040 Note that Profile.calibrate() must be overriden by subclasses.
1041 Improving the accuracy required exploiting detailed knowledge of
1042 profiler internals; the earlier method abstracted away the details
1043 and measured a simplified model instead, but consequently computed
1044 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001045
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001046- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001047 which indicates whether output is intended for the header 'Q'
1048 encoding.
1049
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001050- The SocketServer.ThreadingMixIn class now closes the request after
1051 finish_request() returns. (Not when it errors out though.)
1052
Barry Warsawf6fb1712001-10-19 05:35:40 +00001053- The nntplib module's NNTP.body() method has grown a `file' argument
1054 to allow saving the message body to a file.
1055
1056- The email package has added a class email.Parser.HeaderParser which
1057 only parses headers and does not recurse into the message's body.
1058 Also, the module/class MIMEAudio has been added for representing
1059 audio data (contributed by Anthony Baxter).
1060
1061- ftplib should be able to handle files > 2GB.
1062
1063- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1064 ON, and OFF.
1065
Fred Drakecb7a6b52001-10-22 18:41:51 +00001066- xml.dom.minidom NodeList objects now support the length attribute
1067 and item() method as required by the DOM specifications.
1068
Guido van Rossumed554f62001-10-02 23:15:37 +00001069Tools/Demos
1070
1071- Demo/dns was removed. It no longer serves any purpose; a package
1072 derived from it is now maintained by Anthony Baxter, see
1073 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001074
Barry Warsawf6fb1712001-10-19 05:35:40 +00001075- The freeze tool has been made more robust, and two new options have
1076 been added: -X and -E.
1077
Tim Petersabf925f2001-09-28 21:53:42 +00001078Build
1079
Barry Warsawf6fb1712001-10-19 05:35:40 +00001080- configure will use CXX in LINKCC if CXX is used to build main() and
1081 the system requires to link a C++ main using the C++ compiler.
1082
Tim Petersabf925f2001-09-28 21:53:42 +00001083C API
1084
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001085- The documentation for the tp_compare slot is updated to require that
1086 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1087 not correct. This is not yet enforced but will be enforced in
1088 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1089 "NotImplemented". Right now, -1 should be used for an error return.
1090
Tim Petersd38b1c72001-09-30 05:09:37 +00001091- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1092 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1093 as long) arguments.
1094
Guido van Rossum3c288632001-10-16 21:13:49 +00001095- PyThread_start_new_thread() now returns a long int giving the thread
1096 ID, if one can be calculated; it returns -1 for error, 0 if no
1097 thread ID is calculated (this is an incompatible change, but only
1098 the thread module used this API). This code has only really been
1099 tested on Linux and Windows; other platforms please beware (and
1100 report any bugs or strange behavior).
1101
Guido van Rossum1c486092001-10-19 02:05:35 +00001102- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1103 input.
1104
Tim Petersabf925f2001-09-28 21:53:42 +00001105New platforms
1106
1107Tests
1108
1109Windows
1110
Tim Peters04cf1d32001-10-09 22:39:40 +00001111- Installer: If you install IDLE, and don't disable file-extension
1112 registration, a new "Edit with IDLE" context (right-click) menu entry
1113 is created for .py and .pyw files.
1114
Tim Peters1ce3cf72001-10-01 17:58:40 +00001115- The signal module now supports SIGBREAK on Windows, thanks to Steven
1116 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1117 action remains to call Win32 ExitProcess(). This can be changed via
1118 signal.signal(). For example:
1119
1120 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1121 # (SIGINT) behavior.
1122 import signal
1123 signal.signal(signal.SIGBREAK,
1124 signal.default_int_handler)
1125
1126 try:
1127 while 1:
1128 pass
1129 except KeyboardInterrupt:
1130 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1131 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1132 # program without the possibility for any Python-level cleanup).
1133 print "Clean exit"
1134
Tim Petersabf925f2001-09-28 21:53:42 +00001135
Tim Petersb07352e2001-09-08 01:25:47 +00001136What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001137Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001138===========================
1139
Guido van Rossum808eea72001-09-25 04:15:41 +00001140Type/class unification and new-style classes
1141
1142- pydoc and inspect are now aware of new-style classes;
1143 e.g. help(list) at the interactive prompt now shows proper
1144 documentation for all operations on list objects.
1145
1146- Applications using Jim Fulton's ExtensionClass module can now safely
1147 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1148 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1149 examples also work again. It is hoped that Gtk and Boost also work
1150 with 2.2a4 and beyond. (If you can confirm this, please write
1151 webmaster@python.org; if there are still problems, please open a bug
1152 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001153
Tim Peters66c1a522001-09-24 21:17:50 +00001154- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001155 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001156 in the constructed property object. fget, fset and fdel weren't
1157 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1158 associate a docstring with a property.
1159
Guido van Rossum808eea72001-09-25 04:15:41 +00001160- Comparison overloading is now more completely implemented. For
1161 example, a str subclass instance can properly be compared to a str
1162 instance, and it can properly overload comparison. Ditto for most
1163 other built-in object types.
1164
1165- The repr() of new-style classes has changed; instead of <type
1166 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1167 *except* for built-in types, which are still rendered as <type
1168 'Foo'> (to avoid upsetting existing code that might parse or
1169 otherwise rely on repr() of certain type objects).
1170
1171- The repr() of new-style objects is now always <Foo object at XXX>;
1172 previously, it was sometimes <Foo instance at XXX>.
1173
1174- For new-style classes, what was previously called __getattr__ is now
1175 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001176 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001177 one in classic classes is defined which is called only if regular
1178 attribute access raises AttributeError; to catch *all* attribute
1179 access, you can use __getattribute__ (for new-style classes). If
1180 both are defined, __getattribute__ is called first, and if it raises
1181 AttributeError, __getattr__ is called.
1182
1183- The __class__ attribute of new-style objects can be assigned to.
1184 The new class must have the same C-level object layout as the old
1185 class.
1186
1187- The builtin file type can be subclassed now. In the usual pattern,
1188 "file" is the name of the builtin type, and file() is a new builtin
1189 constructor, with the same signature as the builtin open() function.
1190 file() is now the preferred way to open a file.
1191
1192- Previously, __new__ would only see sequential arguments passed to
1193 the type in a constructor call; __init__ would see both sequential
1194 and keyword arguments. This made no sense whatsoever any more, so
1195 now both __new__ and __init__ see all arguments.
1196
1197- Previously, hash() applied to an instance of a subclass of str or
1198 unicode always returned 0. This has been repaired.
1199
1200- Previously, an operation on an instance of a subclass of an
1201 immutable type (int, long, float, complex, tuple, str, unicode),
1202 where the subtype didn't override the operation (and so the
1203 operation was handled by the builtin type), could return that
1204 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001205 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001206 with the same value as s.
1207
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001208- Provisional support for pickling new-style objects has been added.
1209
Guido van Rossum808eea72001-09-25 04:15:41 +00001210Core
1211
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001212- file.writelines() now accepts any iterable object producing strings.
1213
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001214- PyUnicode_FromEncodedObject() now works very much like
1215 PyObject_Str(obj) in that it tries to use __str__/tp_str
1216 on the object if the object is not a string or buffer. This
1217 makes unicode() behave like str() when applied to non-string/buffer
1218 objects.
1219
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001220- PyFile_WriteObject now passes Unicode objects to the file's write
1221 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001222 of a print statement must support Unicode objects, i.e. they must
1223 at least convert them into ASCII strings.
1224
Guido van Rossum624c8af2001-09-18 15:21:04 +00001225- Thread scheduling on Solaris should be improved; it is no longer
1226 necessary to insert a small sleep at the start of a thread in order
1227 to let other runnable threads be scheduled.
1228
Tim Petersb07352e2001-09-08 01:25:47 +00001229Library
1230
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001231- StringIO.StringIO instances and cStringIO.StringIO instances support
1232 read character buffer compatible objects for their .write() methods.
1233 These objects are converted to strings and then handled as such
1234 by the instances.
1235
Barry Warsaw2f600732001-09-24 04:28:10 +00001236- The "email" package has been added. This is basically a port of the
1237 mimelib package <http://sf.net/projects/mimelib> with API changes
1238 and some implementations updated to use iterators and generators.
1239
Tim Peters8a9c2842001-09-22 21:30:22 +00001240- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1241 restores the ability of Tools/scripts/ndiff.py to start producing output
1242 before the entire comparison is complete.
1243
Barry Warsaw58b072d2001-09-22 04:44:21 +00001244- StringIO.StringIO instances and cStringIO.StringIO instances support
1245 iteration just like file objects (i.e. their .readline() method is
1246 called for each iteration until it returns an empty string).
1247
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001248- The codecs module has grown four new helper APIs to access
1249 builtin codecs: getencoder(), getdecoder(), getreader(),
1250 getwriter().
1251
Guido van Rossum624c8af2001-09-18 15:21:04 +00001252- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1253 simplifies writing XML RPC servers.
1254
Barry Warsaw647d5e82001-09-28 17:01:02 +00001255- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001256 after interpretation of symbolic links. On non-Unix systems, this
1257 is an alias for os.path.abspath().
1258
Tim Peters16a77ad2001-09-08 04:00:12 +00001259- operator.indexOf() (PySequence_Index() in the C API) now works with any
1260 iterable object.
1261
Guido van Rossum624c8af2001-09-18 15:21:04 +00001262- smtplib now supports various authentication and security features of
1263 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001264
Guido van Rossum624c8af2001-09-18 15:21:04 +00001265- hmac: a new module implementing keyed hashing for message
1266 authentication.
1267
1268- mimetypes now recognizes more extensions and file types. At the
1269 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001270
Guido van Rossum624c8af2001-09-18 15:21:04 +00001271- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001272 Python 2.2 bytecode generation. It has also been promoted from a
1273 Tool to a standard library package. (Tools/compiler still exists as
1274 a sample driver.)
1275
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001276Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001277
Tim Petersb07352e2001-09-08 01:25:47 +00001278Build
1279
Guido van Rossum624c8af2001-09-18 15:21:04 +00001280- Large file support (LFS) is now automatic when the platform supports
1281 it; no more manual configuration tweaks are needed. On Linux, at
1282 least, it's possible to have a system whose C library supports large
1283 files but whose kernel doesn't; in this case, large file support is
1284 still enabled but doesn't do you any good unless you upgrade your
1285 kernel or share your Python executable with another system whose
1286 kernel has large file support.
1287
1288- The configure script now supplies plausible defaults in a
1289 cross-compilation environment. This doesn't mean that the supplied
1290 values are always correct, or that cross-compilation now works
1291 flawlessly -- but it's a first step (and it shuts up most of
1292 autoconf's warnings about AC_TRY_RUN).
1293
1294- The Unix build is now a bit less chatty, courtesy of the parser
1295 generator. The build is completely silent (except for errors) when
1296 using "make -s", thanks to a -q option to setup.py.
1297
Tim Petersb07352e2001-09-08 01:25:47 +00001298C API
1299
Guido van Rossum624c8af2001-09-18 15:21:04 +00001300- The "structmember" API now supports some new flag bits to deny read
1301 and/or write access to attributes in restricted execution mode.
1302
Tim Petersb07352e2001-09-08 01:25:47 +00001303New platforms
1304
Guido van Rossum624c8af2001-09-18 15:21:04 +00001305- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1306 (http://familiar.handhelds.org).
1307
Tim Petersb07352e2001-09-08 01:25:47 +00001308Tests
1309
Tim Peters8a9c2842001-09-22 21:30:22 +00001310- The "classic" standard tests, which work by comparing stdout to
1311 an expected-output file under Lib/test/output/, no longer stop at
1312 the first mismatch. Instead the test is run to completion, and a
1313 variant of ndiff-style comparison is used to report all differences.
1314 This is much easier to understand than the previous style of reporting.
1315
1316- The unittest-based standard tests now use regrtest's test_main()
1317 convention, instead of running as a side-effect of merely being
1318 imported. This allows these tests to be run in more natural and
1319 flexible ways as unittests, outside the regrtest framework.
1320
1321- regrtest.py is much better integrated with unittest and doctest now,
1322 especially in regard to reporting errors.
1323
Tim Petersb07352e2001-09-08 01:25:47 +00001324Windows
1325
Guido van Rossum624c8af2001-09-18 15:21:04 +00001326- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001327 that support it (NTFS under Windows 2000). See "What's New in
1328 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001329
Tim Petersb07352e2001-09-08 01:25:47 +00001330
Tim Petersedc99312001-08-22 21:36:50 +00001331What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001332Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001333===========================
1334
1335Core
1336
Tim Peters9fffa3e2001-09-04 05:14:19 +00001337- Conversion of long to float now raises OverflowError if the long is too
1338 big to represent as a C double.
1339
Tim Peters32f453e2001-09-03 08:35:41 +00001340- The 3-argument builtin pow() no longer allows a third non-None argument
1341 if either of the first two arguments is a float, or if both are of
1342 integer types and the second argument is negative (in which latter case
1343 the arguments are converted to float, so this is really the same
1344 restriction).
1345
Tim Peters5d2b77c2001-09-03 05:47:38 +00001346- The builtin dir() now returns more information, and sometimes much
1347 more, generally naming all attributes of an object, and all attributes
1348 reachable from the object via its class, and from its class's base
1349 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1350 an empty list. In 2.2a3,
1351
1352 >>> dir([])
1353 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1354 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1355 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1356 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1357 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1358 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1359 'reverse', 'sort']
1360
1361 dir(module) continues to return only the module's attributes, though.
1362
Tim Petersbdee63f2001-09-02 03:40:59 +00001363- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001364 than raising OverflowError. This is a partial implementation of PEP
1365 237. You can use -Wdefault::OverflowWarning to enable a warning for
1366 this situation, and -Werror::OverflowWarning to revert to the old
1367 OverflowError exception.
1368
Guido van Rossum61c345f2001-09-04 03:26:15 +00001369- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001370 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001371 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1372 -Qold, meaning the / operator has its classic meaning and no
1373 warnings are issued. Using -Qwarn issues a run-time warning about
1374 all uses of classic division for int and long arguments; -Qwarnall
1375 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001376 (for use with fixdiv.py).
1377 [Note: the remainder of this paragraph (preserved below) became
1378 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1379 <obsolete>
1380 Using -Qnew is questionable; it turns on new division by default, but
1381 only in the __main__ module. You can usefully combine -Qwarn or
1382 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1383 warns about classic division everywhere else.
1384 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001385
Tim Petersbdee63f2001-09-02 03:40:59 +00001386- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001387 long, float, str, unicode, and tuple. (The types complex, list and
1388 dictionary can also be subclassed; this was introduced earlier.)
1389 Note that restrictions apply when subclassing immutable built-in
1390 types: you can only affect the value of the instance by overloading
1391 __new__. You can add mutable attributes, and the subclass instances
1392 will have a __dict__ attribute, but you cannot change the "value"
1393 (as implemented by the base class) of an immutable subclass instance
1394 once it is created.
1395
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001396- The dictionary constructor now takes an optional argument, a
1397 mapping-like object, and initializes the dictionary from its
1398 (key, value) pairs.
1399
Tim Petersbdee63f2001-09-02 03:40:59 +00001400- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001401 "cooperative super calls" in a multiple inheritance setting. For an
1402 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1403
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001404- A new built-in type, property, has been added. This enables the
1405 creation of "properties". These are attributes implemented by
1406 getter and setter functions (or only one of these for read-only or
1407 write-only attributes), without the need to override __getattr__.
1408 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001409
Tim Petersbdee63f2001-09-02 03:40:59 +00001410- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001411 liberalized, to allow leading zeroes. Examples of literals now
1412 legal that were SyntaxErrors before:
1413
1414 00.0 0e3 0100j 07.5 00000000000000000008.
1415
Tim Petersbdee63f2001-09-02 03:40:59 +00001416- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001417 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1418
Tim Petersedc99312001-08-22 21:36:50 +00001419Library
1420
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001421- telnetlib includes symbolic names for the options, and support for
1422 setting an option negotiation callback.
1423
Tim Petersa40c7932001-09-05 22:36:56 +00001424- The new C standard no longer requires that math libraries set errno to
1425 ERANGE on overflow. For platform libraries that exploit this new
1426 freedom, Python's overflow-checking was wholly broken. A new overflow-
1427 checking scheme attempts to repair that, but may not be reliable on all
1428 platforms (C doesn't seem to provide anything both useful and portable
1429 in this area anymore).
1430
Martin v. Löwis44f86962001-09-05 13:44:54 +00001431- Asynchronous timeout actions are available through the new class
1432 threading.Timer.
1433
Tim Peters78526162001-09-05 00:53:45 +00001434- math.log and math.log10 now return sensible results for even huge
1435 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1436
Tim Petersbdee63f2001-09-02 03:40:59 +00001437- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001438 currently held. See the docs for the imp module.
1439
Tim Petersbdee63f2001-09-02 03:40:59 +00001440- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001441 dumps containing ints written on platforms where Python ints are 8 bytes.
1442 When read on a box where Python ints are 4 bytes, such values are
1443 converted to Python longs.
1444
Tim Petersbdee63f2001-09-02 03:40:59 +00001445- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001446 code objects is no longer allowed. This plugs a security hole.
1447
Steve Purcell6091cd62001-09-06 16:05:17 +00001448- unittest.TestResult instances no longer store references to tracebacks
1449 generated by test failures. This prevents unexpected dangling references
1450 to objects that should be garbage collected between tests.
1451
Tim Petersedc99312001-08-22 21:36:50 +00001452Tools
1453
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001454- Tools/scripts/fixdiv.py has been added which can be used to fix
1455 division operators as per PEP 238.
1456
Tim Petersedc99312001-08-22 21:36:50 +00001457Build
1458
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001459- If you are an adventurous person using Mac OS X you may want to look at
1460 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1461 application, which can be used for experimenting with Carbon or Cocoa.
1462 Discussion of this on pythonmac-sig, please.
1463
Tim Peters7eea37e2001-09-04 22:08:56 +00001464C API
1465
1466- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001467
Tim Peters9fffa3e2001-09-04 05:14:19 +00001468- Note that PyLong_AsDouble can fail! This has always been true, but no
1469 callers checked for it. It's more likely to fail now, because overflow
1470 errors are properly detected now. The proper way to check:
1471
1472 double x = PyLong_AsDouble(some_long_object);
1473 if (x == -1.0 && PyErr_Occurred()) {
1474 /* The conversion failed. */
1475 }
1476
Tim Petersbdee63f2001-09-02 03:40:59 +00001477- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001478 compile but will not participate in GC. To upgrade an extension
1479 module:
1480
1481 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001482
Neil Schemenauer4042c692001-08-30 15:38:01 +00001483 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1484 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001485
Neil Schemenauer4042c692001-08-30 15:38:01 +00001486 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1487 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001488
Neil Schemenauer4042c692001-08-30 15:38:01 +00001489 - remove PyGC_HEAD_SIZE from object size calculations
1490
1491 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1492
Tim Petersbdee63f2001-09-02 03:40:59 +00001493- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001494 These can be used safely to construct string objects from a
1495 sprintf-style format string (similar to the format string supported
1496 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001497
Tim Petersedc99312001-08-22 21:36:50 +00001498New platforms
1499
Tim Petersb7da0902001-09-02 23:01:43 +00001500- Stephen Hansen contributed patches sufficient to get a clean compile
1501 under Borland C (Windows), but he reports problems running it and ran
1502 out of time to complete the port. Volunteers? Expect a MemoryError
1503 when importing the types module; this is probably shallow, and
1504 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001505
Tim Petersedc99312001-08-22 21:36:50 +00001506Tests
1507
1508Windows
1509
Tim Peters6e13a562001-09-06 00:32:15 +00001510- Large file support is now enabled on Win32 platforms as well as on
1511 Win64. This means that, for example, you can use f.tell() and f.seek()
1512 to manipulate files larger than 2 gigabytes (provided you have enough
1513 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001514 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1515 filesize limit, and large file support makes no difference there.
1516 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1517 NTFS has no practical limit on file size, and files of any size can be
1518 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001519
Tim Petersbdee63f2001-09-02 03:40:59 +00001520- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001521 points to command.com (patch from Brian Quinlan).
1522
Tim Petersedc99312001-08-22 21:36:50 +00001523
Tim Peters20f51a72001-07-21 02:31:40 +00001524What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001525Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001526===========================
1527
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001528Build
1529
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001530- Tim Peters developed a brand new Windows installer using Wise 8.1,
1531 generously donated to us by Wise Solutions.
1532
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001533- configure supports a new option --enable-unicode, with the values
1534 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1535 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001536
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001537- A new configure option --enable-framework builds a Mac OS X framework,
1538 which "make frameworkinstall" will install. This provides a starting
1539 point for more mac-like functionality, join pythonmac-sig@python.org
1540 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001541
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001542- The NeXT platform is no longer supported.
1543
1544- The `new' module is now statically linked.
1545
Tim Peters0afb6092001-08-15 06:06:44 +00001546Tools
1547
1548- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001549 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001550 the module docstring for details.
1551
Tim Peters20f51a72001-07-21 02:31:40 +00001552Tests
1553
Tim Peters5e824c32001-08-12 22:25:01 +00001554- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001555 platforms, allowing to give clearer test result output. regrtest
1556 also has optional --use/-u switch to run normally disabled tests
1557 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001558
Tim Peters20f51a72001-07-21 02:31:40 +00001559- Several new tests in the standard test suite, with special thanks to
1560 Nick Mathewson.
1561
1562Core
1563
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001564- The floor division operator // has been added as outlined in PEP
1565 238. The / operator still provides classic division (and will until
1566 Python 3.0) unless "from __future__ import division" is included, in
1567 which case the / operator will provide true division. The operator
1568 module provides truediv() and floordiv() functions. Augmented
1569 assignment variants are included, as are the equivalent overloadable
1570 methods and C API methods. See the PEP for a full discussion:
1571 <http://python.sf.net/peps/pep-0238.html>
1572
Tim Peters6cd6a822001-08-17 22:11:27 +00001573- Future statements are now effective in simulated interactive shells
1574 (like IDLE). This should "just work" by magic, but read Michael
1575 Hudson's "Future statements in simulated shells" PEP 264 for full
1576 details: <http://python.sf.net/peps/pep-0264.html>.
1577
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001578- The type/class unification (PEP 252-253) was integrated into the
1579 trunk and is not so tentative any more (the exact specification of
1580 some features is still tentative). A lot of work has done on fixing
1581 bugs and adding robustness and features (performance still has to
1582 come a long way).
1583
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001584- Warnings about a mismatch in the Python API during extension import
1585 now use the Python warning framework (which makes it possible to
1586 write filters for these warnings).
1587
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001588- A function's __dict__ (aka func_dict) will now always be a
1589 dictionary. It used to be possible to delete it or set it to None,
1590 but now both actions raise TypeErrors. It is still legal to set it
1591 to a dictionary object. Getting func.__dict__ before any attributes
1592 have been assigned now returns an empty dictionary instead of None.
1593
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001594- A new command line option, -E, was added which disables the use of
1595 all environment variables, or at least those that are specifically
1596 significant to Python. Usually those have a name starting with
1597 "PYTHON". This was used to fix a problem where the tests fail if
1598 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1599 older distribution.
1600
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001601Library
1602
Tim Peters5e824c32001-08-12 22:25:01 +00001603- New class Differ and new functions ndiff() and restore() in difflib.py.
1604 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001605 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001606
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001607- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1608 value using the minimal quoting required for the value; more
1609 reliable than using xml.sax.saxutils.escape() for attribute values.
1610
1611- Readline completion support for cmd.Cmd was added.
1612
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001613- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1614
1615- Added function threading.BoundedSemaphore()
1616
1617- Added Ka-Ping Yee's cgitb.py module.
1618
1619- The `new' module now exposes the CO_xxx flags.
1620
Martin v. Löwis560da622001-11-24 09:24:51 +00001621- The gc module offers the get_referents function.
1622
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001623New platforms
1624
1625C API
1626
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001627- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1628 which provide a cross-platform implementations for the
1629 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1630 the standard sprintf() and vsprintf() C lib APIs, these versions
1631 apply bounds checking on the used buffer which enhances protection
1632 against buffer overruns.
1633
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001634- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001635 and extensions using different Unicode widths is rendered next to
1636 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001637 will result in an ImportError. Unicode extensions writers must make
1638 sure to check the Unicode width compatibility in their extensions by
1639 using at least one of the mangled Unicode APIs in the extension.
1640
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001641- Two new flags METH_NOARGS and METH_O are available in method definition
1642 tables to simplify implementation of methods with no arguments and a
1643 single untyped argument. Calling such methods is more efficient than
1644 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1645 deprecated.
1646
Tim Petersc1731372001-08-04 08:12:36 +00001647Windows
1648
1649- "import module" now compiles module.pyw if it exists and nothing else
1650 relevant is found.
1651
Tim Peters20f51a72001-07-21 02:31:40 +00001652
Guido van Rossum55a78992001-07-17 17:22:32 +00001653What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001654Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001655===========================
1656
1657Core
Tim Petersa814db52001-05-14 07:05:58 +00001658
Tim Peters6d6c1a32001-08-02 04:15:00 +00001659- TENTATIVELY, a large amount of code implementing much of what's
1660 described in PEP 252 (Making Types Look More Like Classes) and PEP
1661 253 (Subtyping Built-in Types) was added. This will be released
1662 with Python 2.2a1. Documentation will be provided separately
1663 through http://www.python.org/2.2/. The purpose of releasing this
1664 with Python 2.2a1 is to test backwards compatibility. It is
1665 possible, though not likely, that a decision is made not to release
1666 this code as part of 2.2 final, if any serious backwards
1667 incompapatibilities are found during alpha testing that cannot be
1668 repaired.
1669
Guido van Rossum55a78992001-07-17 17:22:32 +00001670- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001671 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001672 more 'yield' statements. See PEP 255. Since this adds a new
1673 keyword to the language, this feature must be enabled by including a
1674 future statement: "from __future__ import generators" (see PEP 236).
1675 Generators will become a standard feature in a future release
1676 (probably 2.3). Without this future statement, 'yield' remains an
1677 ordinary identifier, but a warning is issued each time it is used.
1678 (These warnings currently don't conform to the warnings framework of
1679 PEP 230; we intend to fix this in 2.2a2.)
1680
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001681- The UTF-16 codec was modified to be more RFC compliant. It will now
1682 only remove BOM characters at the start of the string and then
1683 only if running in native mode (UTF-16-LE and -BE won't remove a
1684 leading BMO character).
1685
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001686- Strings now have a new method .decode() to complement the already
1687 existing .encode() method. These two methods provide direct access
1688 to the corresponding decoders and encoders of the registered codecs.
1689
1690 To enhance the usability of the .encode() method, the special
1691 casing of Unicode object return values was dropped (Unicode objects
1692 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001693
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001694 Both methods will now return whatever the codec in charge of the
1695 requested encoding returns as object, e.g. Unicode codecs will
1696 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1697 will return u"äöü"). This enables codec writer to create codecs
1698 for various simple to use conversions.
1699
1700 New codecs were added to demonstrate these new features (the .encode()
1701 and .decode() columns indicate the type of the returned objects):
1702
1703 Name | .encode() | .decode() | Description
1704 ----------------------------------------------------------------------
1705 uu | string | string | UU codec (e.g. for email)
1706 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001707 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001708 zlib | string | string | zlib compression
1709 hex | string | string | 2-byte hex codec
1710 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1711
Mark Hammond2a0af792001-05-14 03:09:36 +00001712- Some operating systems now support the concept of a default Unicode
1713 encoding for file system operations. Notably, Windows supports 'mbcs'
1714 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001715 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001716 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001717
1718 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001719 functions that return filenames (such as os.listdir()) to return Python
1720 string objects pre-encoded using the default file system encoding for
1721 the platform. As this encoding is likely to be different from Python's
1722 default encoding, converting this name to a Unicode object before passing
1723 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001724 would attempt to use its default encoding (generally ASCII) rather than
1725 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001726
Tim Petersa814db52001-05-14 07:05:58 +00001727 In general, this change simply removes surprises when working with
1728 Unicode and the file system, making these operations work as you expect,
1729 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001730 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001731
Tim Peters61dff2b2001-05-08 15:43:37 +00001732- Float (and complex) literals in source code were evaluated to full
1733 precision only when running from a .py file; the same code loaded from a
1734 .pyc (or .pyo) file could suffer numeric differences starting at about the
1735 12th significant decimal digit. For example, on a machine with IEEE-754
1736 floating arithmetic,
1737
1738 x = 9007199254740992.0
1739 print long(x)
1740
1741 printed 9007199254740992 if run directly from .py, but 9007199254740000
1742 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1743 str(float) instead of repr(float) when building code objects. marshal
1744 now uses repr(float) instead, which should reproduce floats to full
1745 machine precision (assuming the platform C float<->string I/O conversion
1746 functions are of good quality).
1747
1748 This may cause floating-point results to change in some cases, and
1749 usually for the better, but may also cause numerically unstable
1750 algorithms to break.
1751
Tim Peters2f228e72001-05-13 00:19:31 +00001752- The implementation of dicts suffers fewer collisions, which has speed
1753 benefits. However, the order in which dict entries appear in dict.keys(),
1754 dict.values() and dict.items() may differ from previous releases for a
1755 given dict. Nothing is defined about this order, so no program should
1756 rely on it. Nevertheless, it's easy to write test cases that rely on the
1757 order by accident, typically because of printing the str() or repr() of a
1758 dict to an "expected results" file. See Lib/test/test_support.py's new
1759 sortdict(dict) function for a simple way to display a dict in sorted
1760 order.
1761
Tim Peters7a3bfc32001-06-12 01:22:22 +00001762- Many other small changes to dicts were made, resulting in faster
1763 operation along the most common code paths.
1764
Guido van Rossum10315822001-05-01 20:54:30 +00001765- Dictionary objects now support the "in" operator: "x in dict" means
1766 the same as dict.has_key(x).
1767
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001768- The update() method of dictionaries now accepts generic mapping
1769 objects. Specifically the argument object must support the .keys()
1770 and __getitem__() methods. This allows you to say, for example,
1771 {}.update(UserDict())
1772
Guido van Rossum10315822001-05-01 20:54:30 +00001773- Iterators were added; this is a generalized way of providing values
1774 to a for loop. See PEP 234. There's a new built-in function iter()
1775 to return an iterator. There's a new protocol to get the next value
1776 from an iterator using the next() method (in Python) or the
1777 tp_iternext slot (in C). There's a new protocol to get iterators
1778 using the __iter__() method (in Python) or the tp_iter slot (in C).
1779 Iterating (i.e. a for loop) over a dictionary generates its keys.
1780 Iterating over a file generates its lines.
1781
Tim Petersf553f892001-05-01 20:45:31 +00001782- The following functions were generalized to work nicely with iterator
1783 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001784 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001785 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1786 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001787 join() method of strings
1788 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001789 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1790 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001791 right-hand side of assignment statements with multiple targets, such as
1792 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001793
Tim Petersd85e1022001-05-11 21:51:48 +00001794- Accessing module attributes is significantly faster (for example,
1795 random.random or os.path or yourPythonModule.yourAttribute).
1796
Tim Peterse63415e2001-05-08 04:38:29 +00001797- Comparing dictionary objects via == and != is faster, and now works even
1798 if the keys and values don't support comparisons other than ==.
1799
Tim Peters95bf9392001-05-10 08:32:44 +00001800- Comparing dictionaries in ways other than == and != is slower: there were
1801 insecurities in the dict comparison implementation that could cause Python
1802 to crash if the element comparison routines for the dict keys and/or
1803 values mutated the dicts. Making the code bulletproof slowed it down.
1804
Tim Peterseb28ef22001-06-02 05:27:19 +00001805- Collisions in dicts are resolved via a new approach, which can help
1806 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001807 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001808 faster now. Thanks to Christian Tismer for pointing out the cause and
1809 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001810
Tim Peters52e155e2001-06-16 05:42:57 +00001811- repr() is much faster for large containers (dict, list, tuple).
1812
1813
Tim Petersa814db52001-05-14 07:05:58 +00001814Library
1815
Fred Drake960fdf92001-07-20 18:38:26 +00001816- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1817 were added to the string module. These a locale-indenpendent
1818 constants, unlike letters, lowercase, and uppercase. These are now
1819 use in appropriate locations in the standard library.
1820
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001821- The flags used in dlopen calls can now be configured using
1822 sys.setdlopenflags and queried using sys.getdlopenflags.
1823
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001824- Fredrik Lundh's xmlrpclib is now a standard library module. This
1825 provides full client-side XML-RPC support. In addition,
1826 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1827 one asyncore-based). Thanks to Eric Raymond for the documentation.
1828
Guido van Rossum643d3912001-07-05 14:46:25 +00001829- The xrange() object is simplified: it no longer supports slicing,
1830 repetition, comparisons, efficient 'in' checking, the tolist()
1831 method, or the start, stop and step attributes. See PEP 260.
1832
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001833- A new function fnmatch.filter to filter lists of file names was added.
1834
Barry Warsawffd674d2001-05-22 16:00:10 +00001835- calendar.py uses month and day names based on the current locale.
1836
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001837- strop is now *really* obsolete (this was announced before with 1.6),
1838 and issues DeprecationWarning when used (except for the four items
1839 that are still imported into string.py).
1840
Tim Petersa814db52001-05-14 07:05:58 +00001841- Cookie.py now sorts key+value pairs by key in output strings.
1842
1843- pprint.isrecursive(object) didn't correctly identify recursive objects.
1844 Now it does.
1845
Tim Peters95b3f782001-05-14 18:39:41 +00001846- pprint functions now much faster for large containers (tuple, list, dict).
1847
Tim Peters7b9542a2001-06-10 23:40:19 +00001848- New 'q' and 'Q' format codes in the struct module, corresponding to C
1849 types "long long" and "unsigned long long" (on Windows, __int64). In
1850 native mode, these can be used only when the platform C compiler supports
1851 these types (when HAVE_LONG_LONG is #define'd by the Python config
1852 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001853 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1854 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001855
Guido van Rossum83213cc2001-06-12 16:48:52 +00001856- The site module installs a new built-in function 'help' that invokes
1857 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1858 it displays a message reminding the user to use 'help()' or
1859 'help(object)'.
1860
Tim Petersa814db52001-05-14 07:05:58 +00001861Tests
1862
1863- New test_mutants.py runs dict comparisons where the key and value
1864 comparison operators mutute the dicts randomly during comparison. This
1865 rapidly causes Python to crash under earlier releases (not for the faint
1866 of heart: it can also cause Win9x to freeze or reboot!).
1867
1868- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001869 pprint.isreadable() return sensible results. Also verifies that simple
1870 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001871
Tim Peters4324aa32001-05-28 22:30:08 +00001872C API
1873
1874- Removed the unused last_is_sticky argument from the internal
1875 _PyTuple_Resize(). If this affects you, you were cheating.
1876
1877
Guido van Rossum55a78992001-07-17 17:22:32 +00001878======================================================================
1879
1880
Guido van Rossumffe13be2001-04-16 18:46:45 +00001881What's New in Python 2.1 (final)?
1882=================================
1883
1884We only changed a few things since the last release candidate, all in
1885Python library code:
1886
1887- A bug in the locale module was fixed that affected locales which
1888 define no grouping for numeric formatting.
1889
1890- A few bugs in the weakref module's implementations of weak
1891 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1892 and the test suite was updated to check for these bugs.
1893
1894- An old bug in the os.path.walk() function (introduced in Python
1895 2.0!) was fixed: a non-existent file would cause an exception
1896 instead of being ignored.
1897
1898- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1899 PyChecker.
1900
1901
Guido van Rossum5b08f132001-04-16 02:05:23 +00001902What's New in Python 2.1c2?
1903===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001904
Guido van Rossum5b08f132001-04-16 02:05:23 +00001905A flurry of small changes, and one showstopper fixed in the nick of
1906time made it necessary to release another release candidate. The list
1907here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001908
Guido van Rossum5b08f132001-04-16 02:05:23 +00001909Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001910
Guido van Rossum5b08f132001-04-16 02:05:23 +00001911- Tim discovered a nasty bug in the dictionary code, caused by
1912 PyDict_Next() calling dict_resize(), and the GC code's use of
1913 PyDict_Next() violating an assumption in dict_items(). This was
1914 fixed with considerable amounts of band-aid, but the net effect is a
1915 saner and more robust implementation.
1916
1917- Made a bunch of symbols static that were accidentally global.
1918
1919Build and Ports
1920
1921- The setup.py script didn't check for a new enough version of zlib
1922 (1.1.3 is needed). Now it does.
1923
1924- Changed "make clean" target to also remove shared libraries.
1925
1926- Added a more general warning about the SGI Irix optimizer to README.
1927
1928Library
1929
1930- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1931 omitted the slash between host and file.html.
1932
1933- The mailbox module's _Mailbox class contained a completely broken
1934 and undocumented seek() method. Ripped it out.
1935
1936- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1937 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1938
1939- Fixed a few last-minute bugs in unittest.
1940
1941Extensions
1942
1943- Reverted the patch to the OpenSSL code in socketmodule.c to support
1944 RAND_status() and the EGD, and the subsequent patch that tried to
1945 fix it for pre-0.9.5 versions; the problem with the patch is that on
1946 some systems it issues a warning whenever socket is imported, and
1947 that's unacceptable.
1948
1949Tests
1950
1951- Fixed the pickle tests to work with "import test.test_pickle".
1952
1953- Tweaked test_locale.py to actually run the test Windows.
1954
1955- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1956 not "wb" (which is not a valid mode at all).
1957
1958- Fix pstats browser crashes. Import readline if it exists to make
1959 the user interface nicer.
1960
1961- Add "import thread" to the top of test modules that import the
1962 threading module (test_asynchat and test_threadedtempfile). This
1963 prevents test failures caused by a broken threading module resulting
1964 from a previously caught failed import.
1965
1966- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1967 needed on some platforms (e.g. Solaris 8) when the tests are run
1968 twice in succession.
1969
1970- Skip rather than fail test_sunaudiodev if no audio device is found.
1971
1972
1973What's New in Python 2.1c1?
1974===========================
1975
1976This list was significantly updated when 2.1c2 was released; the 2.1c1
1977release didn't mention most changes that were actually part of 2.1c1:
1978
1979Legal
1980
1981- Copyright was assigned to the Python Software Foundation (PSF) and a
1982 PSF license (very similar to the CNRI license) was added.
1983
1984- The CNRI copyright notice was updated to include 2001.
1985
1986Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001987
Guido van Rossumc9932722001-04-12 02:31:27 +00001988- After a public outcry, assignment to __debug__ is no longer illegal;
1989 instead, a warning is issued. It will become illegal in 2.2.
1990
Guido van Rossum5b08f132001-04-16 02:05:23 +00001991- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1992 "%#x" now always prepends "0x", even if the value is zero.
1993
1994- Fixed some nits in the bytecode compiler.
1995
1996- Fixed core dumps when calling certain kinds of non-functions.
1997
1998- Fixed various core dumps caused by reference count bugs.
1999
2000Build and Ports
2001
2002- Use INSTALL_SCRIPT to install script files.
2003
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002004- New port: SCO Unixware 7, by Billy G. Allie.
2005
Guido van Rossum5b08f132001-04-16 02:05:23 +00002006- Updated RISCOS port.
2007
2008- Updated BeOS port and notes.
2009
2010- Various other porting problems resolved.
2011
2012Library
2013
2014- The TERMIOS and SOCKET modules are now truly obsolete and
2015 unnecessary. Their symbols are incorporated in the termios and
2016 socket modules.
2017
2018- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
2019 better tests for pickling.
2020
2021- threading: make Condition.wait() robust against KeyboardInterrupt.
2022
2023- zipfile: add support to zipfile to support opening an archive
2024 represented by an open file rather than a file name. Fix bug where
2025 the archive was not properly closed. Fixed a bug in this bugfix
2026 where flush() was called for a read-only file.
2027
2028- imputil: added an uninstall() method to the ImportManager.
2029
2030- Canvas: fixed bugs in lower() and tkraise() methods.
2031
2032- SocketServer: API change (added overridable close_request() method)
2033 so that the TCP server can explicitly close the request.
2034
2035- pstats: Eric Raymond added a simple interactive statistics browser,
2036 invoked when the module is run as a script.
2037
2038- locale: fixed a problem in format().
2039
2040- webbrowser: made it work when the BROWSER environment variable has a
2041 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
2042 KDE 2. Fixed some other nits.
2043
2044- unittest: changes to allow using a different exception than
2045 AssertionError, and added a few more function aliases. Some other
2046 small changes.
2047
2048- urllib, urllib2: fixed redirect problems and a coupleof other nits.
2049
2050- asynchat: fixed a critical bug in asynchat that slipped through the
2051 2.1b2 release. Fixed another rare bug.
2052
2053- Fix some unqualified except: clauses (always a bad code example).
2054
2055XML
2056
2057- pyexpat: new API get_version_string().
2058
2059- Fixed some minidom bugs.
2060
2061Extensions
2062
2063- Fixed a core dump in _weakref. Removed the weakref.mapping()
2064 function (it adds nothing to the API).
2065
2066- Rationalized the use of header files in the readline module, to make
2067 it compile (albeit with some warnings) with the very recent readline
2068 4.2, without breaking for earlier versions.
2069
2070- Hopefully fixed a buffering problem in linuxaudiodev.
2071
2072- Attempted a fix to make the OpenSSL support in the socket module
2073 work again with pre-0.9.5 versions of OpenSSL.
2074
2075Tests
2076
2077- Added a test case for asynchat and asyncore.
2078
2079- Removed coupling between tests where one test failing could break
2080 another.
2081
2082Tools
2083
2084- Ping added an interactive help browser to pydoc, fixed some nits
2085 in the rest of the pydoc code, and added some features to his
2086 inspect module.
2087
2088- An updated python-mode.el version 4.1 which integrates Ken
2089 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2090 much nicer in XEmacs and Emacs. When stepping through your program
2091 with pdb, in either the shell window or the *Python* window, the
2092 source file and line will be tracked by an arrow. Very cool!
2093
2094- IDLE: syntax warnings in interactive mode are changed into errors.
2095
2096- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002097 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002098
2099- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002100
Barry Warsaw11e89c72001-04-11 20:37:57 +00002101
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002102What's New in Python 2.1 beta 2?
2103================================
2104
Guido van Rossum053ae352001-03-22 14:17:21 +00002105(Unlisted are many fixed bugs, more documentation, etc.)
2106
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002107Core language, builtins, and interpreter
2108
Guido van Rossum053ae352001-03-22 14:17:21 +00002109- The nested scopes work (enabled by "from __future__ import
2110 nested_scopes") is completed; in particular, the future now extends
2111 into code executed through exec, eval() and execfile(), and into the
2112 interactive interpreter.
2113
2114- When calling a base class method (e.g. BaseClass.__init__(self)),
2115 this is now allowed even if self is not strictly spoken a class
2116 instance (e.g. when using metaclasses or the Don Beaudry hook).
2117
2118- Slice objects are now comparable but not hashable; this prevents
2119 dict[:] from being accepted but meaningless.
2120
2121- Complex division is now calculated using less braindead algorithms.
2122 This doesn't change semantics except it's more likely to give useful
2123 results in extreme cases. Complex repr() now uses full precision
2124 like float repr().
2125
2126- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2127
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002128- It is illegal to assign to the name __debug__, which is set when the
2129 interpreter starts. It is effectively a compile-time constant.
2130
2131- A warning will be issued if a global statement for a variable
2132 follows a use or assignment of that variable.
2133
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002134Standard library
2135
Guido van Rossum053ae352001-03-22 14:17:21 +00002136- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2137 inspired by JUnit), is now part of the standard library. You now
2138 have a choice of two testing frameworks: unittest requires you to
2139 write testcases as separate code, doctest gathers them from
2140 docstrings. Both approaches have their advantages and
2141 disadvantages.
2142
2143- A new module Tix was added, which wraps the Tix extension library
2144 for Tk. With that module, it is not necessary to statically link
2145 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2146 require" command. See Demo/tix/.
2147
2148- tzparse.py is now obsolete.
2149
2150- In gzip.py, the seek() and tell() methods are removed -- they were
2151 non-functional anyway, and it's better if callers can test for their
2152 existence with hasattr().
2153
2154Python/C API
2155
2156- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2157 that's already in the dictionary during a PyDict_Next() iteration.
2158 This used to fail occasionally when a dictionary resize operation
2159 could be triggered that would rehash all the keys. All other
2160 modifications to the dictionary are still off-limits during a
2161 PyDict_Next() iteration!
2162
2163- New extended APIs related to passing compiler variables around.
2164
2165- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2166 implement isinstance() and issubclass().
2167
2168- Py_BuildValue() now has a "D" conversion to create a Python complex
2169 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002170
Fred Drake4e262a92001-03-22 18:26:47 +00002171- Extensions types which support weak references must now set the
2172 field allocated for the weak reference machinery to NULL themselves;
2173 this is done to avoid the cost of checking each object for having a
2174 weakly referencable type in PyObject_INIT(), since most types are
2175 not weakly referencable.
2176
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002177- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2178 free variables and cell variables to and from the frame's f_locals.
2179
2180- Variants of several functions defined in pythonrun.h have been added
2181 to support the nested_scopes future statement. The variants all end
2182 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2183 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2184 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002185 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002186
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002187Distutils
2188
2189- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2190 into the release tree.
2191
Tim Peters0e57abf2001-05-02 07:39:38 +00002192- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002193 (an uninstaller, more customization of the installer's display)
2194
2195- from Jack Jansen: added Mac-specific code to generate a dialog for
2196 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002197 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002198 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002199
2200- added 'platforms' and 'keywords' to the set of metadata that can be
2201 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002202
2203- applied patches from Jason Tishler to make the compiler class work with
2204 Cygwin.
2205
2206
Tim Peters2fe289a2001-03-01 22:19:38 +00002207What's New in Python 2.1 beta 1?
2208================================
Tim Petersd66595f2001-02-04 03:09:53 +00002209
2210Core language, builtins, and interpreter
2211
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002212- Following an outcry from the community about the amount of code
2213 broken by the nested scopes feature introduced in 2.1a2, we decided
2214 to make this feature optional, and to wait until Python 2.2 (or at
2215 least 6 months) to make it standard. The option can be enabled on a
2216 per-module basis by adding "from __future__ import nested_scopes" at
2217 the beginning of a module (before any other statements, but after
2218 comments and an optional docstring). See PEP 236 (Back to the
2219 __future__) for a description of the __future__ statement. PEP 227
2220 (Statically Nested Scopes) has been updated to reflect this change,
2221 and to clarify the semantics in a number of endcases.
2222
2223- The nested scopes code, when enabled, has been hardened, and most
2224 bugs and memory leaks in it have been fixed.
2225
2226- Compile-time warnings are now generated for a number of conditions
2227 that will break or change in meaning when nested scopes are enabled:
2228
2229 - Using "from...import *" or "exec" without in-clause in a function
2230 scope that also defines a lambda or nested function with one or
2231 more free (non-local) variables. The presence of the import* or
2232 bare exec makes it impossible for the compiler to determine the
2233 exact set of local variables in the outer scope, which makes it
2234 impossible to determine the bindings for free variables in the
2235 inner scope. To avoid the warning about import *, change it into
2236 an import of explicitly name object, or move the import* statement
2237 to the global scope; to avoid the warning about bare exec, use
2238 exec...in... (a good idea anyway -- there's a possibility that
2239 bare exec will be deprecated in the future).
2240
2241 - Use of a global variable in a nested scope with the same name as a
2242 local variable in a surrounding scope. This will change in
2243 meaning with nested scopes: the name in the inner scope will
2244 reference the variable in the outer scope rather than the global
2245 of the same name. To avoid the warning, either rename the outer
2246 variable, or use a global statement in the inner function.
2247
Neil Schemenauera35c6882001-02-27 04:45:05 +00002248- An optional object allocator has been included. This allocator is
2249 optimized for Python objects and should be faster and use less memory
2250 than the standard system allocator. It is not enabled by default
2251 because of possible thread safety problems. The allocator is only
2252 protected by the Python interpreter lock and it is possible that some
2253 extension modules require a thread safe allocator. The object
2254 allocator can be enabled by providing the "--with-pymalloc" option to
2255 configure.
2256
Tim Petersd66595f2001-02-04 03:09:53 +00002257Standard library
2258
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002259- pyexpat now detects the expat version if expat.h defines it. A
2260 number of additional handlers are provided, which are only available
2261 since expat 1.95. In addition, the methods SetParamEntityParsing and
2262 GetInputContext of Parser objects are available with 1.95.x
2263 only. Parser objects now provide the ordered_attributes and
2264 specified_attributes attributes. A new module expat.model was added,
2265 which offers a number of additional constants if 1.95.x is used.
2266
2267- xml.dom offers the new functions registerDOMImplementation and
2268 getDOMImplementation.
2269
2270- xml.dom.minidom offers a toprettyxml method. A number of DOM
2271 conformance issues have been resolved. In particular, Element now
2272 has an hasAttributes method, and the handling of namespaces was
2273 improved.
2274
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002275- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2276 getting information about live Python code, and pydoc.py, a module
2277 for interactively converting docstrings to HTML or text.
2278 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002279 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002280 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2281 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002282
Tim Peters1eff7962001-03-01 02:31:33 +00002283- New library module difflib.py, primarily packaging the SequenceMatcher
2284 class at the heart of the popular ndiff.py file-comparison tool.
2285
2286- doctest.py (a framework for verifying Python code examples in docstrings)
2287 is now part of the std library.
2288
Tim Petersd66595f2001-02-04 03:09:53 +00002289Windows changes
2290
Guido van Rossume3955a82001-03-02 14:05:59 +00002291- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2292 small GUI that lets you browse the module docstrings using your
2293 default web browser.
2294
Tim Peters1eff7962001-03-01 02:31:33 +00002295- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2296 Platforms) is implemented. See
2297
2298 http://python.sourceforge.net/peps/pep-0235.html
2299
2300 for full details, especially the "Current Lower-Left Semantics" section.
2301 The new Windows import rules are simpler than before:
2302
2303 A. If the PYTHONCASEOK environment variable exists, same as
2304 before: silently accept the first case-insensitive match of any
2305 kind; raise ImportError if none found.
2306
2307 B. Else search sys.path for the first case-sensitive match; raise
2308 ImportError if none found.
2309
2310 The same rules have been implented on other platforms with case-
2311 insensitive but case-preserving filesystems too (including Cygwin, and
2312 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002313
Tim Peters25a9ce32001-02-19 07:06:36 +00002314- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2315 what it's supposed to do (and does do under NT and 2000) via direct
2316 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002317 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002318 all Win9x systems before.
2319
Tim Peters1eff7962001-03-01 02:31:33 +00002320- Build: Subproject _test (effectively) renamed to _testcapi.
2321
Tim Peters2fe289a2001-03-01 22:19:38 +00002322New platforms
2323
2324- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2325 Thanks to Steven Majewski!
2326
2327- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2328 Tishler!
2329
Guido van Rossum9089b272001-03-02 06:49:50 +00002330- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2331 Schwertberger! See RISCOS/README for more information -- it seems
2332 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002333 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002334
Tim Peters25a9ce32001-02-19 07:06:36 +00002335
Tim Petersd7b5e882001-01-25 03:36:26 +00002336What's New in Python 2.1 alpha 2?
2337=================================
Tim Peters40ead762001-01-27 05:35:26 +00002338
Tim Petersd7b5e882001-01-25 03:36:26 +00002339Core language, builtins, and interpreter
2340
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002341- Scopes nest. If a name is used in a function or class, but is not
2342 local, the definition in the nearest enclosing function scope will
2343 be used. One consequence of this change is that lambda statements
2344 could reference variables in the namespaces where the lambda is
2345 defined. In some unusual cases, this change will break code.
2346
2347 In all previous version of Python, names were resolved in exactly
2348 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002349 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002350 function A is defined within a function B, the names bound in B are
2351 not visible in A. The new rules make names bound in B visible in A,
2352 unless A contains a name binding that hides the binding in B.
2353
2354 Section 4.1 of the reference manual describes the new scoping rules
2355 in detail. The test script in Lib/test/test_scope.py demonstrates
2356 some of the effects of the change.
2357
2358 The new rules will cause existing code to break if it defines nested
2359 functions where an outer function has local variables with the same
2360 name as globals or builtins used by the inner function. Example:
2361
2362 def munge(str):
2363 def helper(x):
2364 return str(x)
2365 if type(str) != type(''):
2366 str = helper(str)
2367 return str.strip()
2368
2369 Under the old rules, the name str in helper() is bound to the
2370 builtin function str(). Under the new rules, it will be bound to
2371 the argument named str and an error will occur when helper() is
2372 called.
2373
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002374- The compiler will report a SyntaxError if "from ... import *" occurs
2375 in a function or class scope. The language reference has documented
2376 that this case is illegal, but the compiler never checked for it.
2377 The recent introduction of nested scope makes the meaning of this
2378 form of name binding ambiguous. In a future release, the compiler
2379 may allow this form when there is no possibility of ambiguity.
2380
Tim Peters40ead762001-01-27 05:35:26 +00002381- repr(string) is easier to read, now using hex escapes instead of octal,
2382 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2383
2384 >>> "\texample \r\n" + chr(0) + chr(255)
2385 '\texample \r\n\x00\xff' # in 2.1
2386 '\011example \015\012\000\377' # in 2.0
2387
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002388- Functions are now compared and hashed by identity, not by value, since
2389 the func_code attribute is writable.
2390
Fred Drakefb9d7122001-02-01 20:00:40 +00002391- Weak references (PEP 205) have been added. This involves a few
2392 changes in the core, an extension module (_weakref), and a Python
2393 module (weakref). The weakref module is the public interface. It
2394 includes support for "explicit" weak references, proxy objects, and
2395 mappings with weakly held values.
2396
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002397- A 'continue' statement can now appear in a try block within the body
2398 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002399 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002400
Tim Petersd7b5e882001-01-25 03:36:26 +00002401Standard library
2402
Barry Warsaw30dbd142001-01-31 22:14:01 +00002403- mailbox.py now has a new class, PortableUnixMailbox which is
2404 identical to UnixMailbox but uses a more portable scheme for
2405 determining From_ separators. Also, the constructors for all the
2406 classes in this module have a new optional `factory' argument, which
2407 is a callable used when new message classes must be instantiated by
2408 the next() method.
2409
Tim Petersd7b5e882001-01-25 03:36:26 +00002410- random.py is now self-contained, and offers all the functionality of
2411 the now-deprecated whrandom.py. See the docs for details. random.py
2412 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002413 and restoring the internal state of the generator; and jumpahead(n),
2414 for quickly forcing the internal state to be the same as if n calls to
2415 random() had been made. The latter is particularly useful for multi-
2416 threaded programs, creating one instance of the random.Random() class for
2417 each thread, then using .jumpahead() to force each instance to use a
2418 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002419
Tim Peters0de88fc2001-02-01 04:59:18 +00002420- random.py's seed() function is new. For bit-for-bit compatibility with
2421 prior releases, use the whseed function instead. The new seed function
2422 addresses two problems: (1) The old function couldn't produce more than
2423 about 2**24 distinct internal states; the new one about 2**45 (the best
2424 that can be done in the Wichmann-Hill generator). (2) The old function
2425 sometimes produced identical internal states when passed distinct
2426 integers, and there was no simple way to predict when that would happen;
2427 the new one guarantees to produce distinct internal states for all
2428 arguments in [0, 27814431486576L).
2429
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002430- The socket module now supports raw packets on Linux. The socket
2431 family is AF_PACKET.
2432
Tim Peters9ea17ac2001-02-02 05:57:15 +00002433- test_capi.py is a start at running tests of the Python C API. The tests
2434 are implemented by the new Modules/_testmodule.c.
2435
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002436- A new extension module, _symtable, provides provisional access to the
2437 internal symbol table used by the Python compiler. A higher-level
2438 interface will be added on top of _symtable in a future release.
2439
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002440- Removed the obsolete soundex module.
2441
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002442- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2443 the isSameNode method; NamedNodeMap the get method.
2444
2445- xml.sax.expatreader supports the lexical handler property; it
2446 generates comment, startCDATA, and endCDATA events.
2447
Tim Petersee826f82001-01-31 19:39:44 +00002448Windows changes
2449
2450- Build procedure: the zlib project is built in a different way that
2451 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002452 the zlib binary used. See PCbuild\readme.txt for details. Your old
2453 zlib-related directories can be deleted; you'll need to download fresh
2454 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002455
Tim Peters9ea17ac2001-02-02 05:57:15 +00002456- Build: New subproject _test for the benefit of test_capi.py (see above).
2457
Tim Petersb16c56f2001-02-02 21:24:51 +00002458- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2459 interface to some Python compiler internals).
2460
2461- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002462 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002463
Tim Petersa3a3a032000-11-30 05:22:44 +00002464What's New in Python 2.1 alpha 1?
2465=================================
2466
2467Core language, builtins, and interpreter
2468
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002469- There is a new Unicode companion to the PyObject_Str() API
2470 called PyObject_Unicode(). It behaves in the same way as the
2471 former, but assures that the returned value is an Unicode object
2472 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002473
Guido van Rossumf98eda02001-01-17 15:54:45 +00002474- The comparison operators support "rich comparison overloading" (PEP
2475 207). C extension types can provide a rich comparison function in
2476 the new tp_richcompare slot in the type object. The cmp() function
2477 and the C function PyObject_Compare() first try the new rich
2478 comparison operators before trying the old 3-way comparison. There
2479 is also a new C API PyObject_RichCompare() (which also falls back on
2480 the old 3-way comparison, but does not constrain the outcome of the
2481 rich comparison to a Boolean result).
2482
2483 The rich comparison function takes two objects (at least one of
2484 which is guaranteed to have the type that provided the function) and
2485 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2486 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2487 object, which may be NotImplemented (in which case the tp_compare
2488 slot function is used as a fallback, if defined).
2489
2490 Classes can overload individual comparison operators by defining one
2491 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002492 __ge__. There are no explicit "reflected argument" versions of
2493 these; instead, __lt__ and __gt__ are each other's reflection,
2494 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2495 reflection (similar at the C level). No other implications are
2496 made; in particular, Python does not assume that == is the Boolean
2497 inverse of !=, or that < is the Boolean inverse of >=. This makes
2498 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002499
2500 Classes or types that want to implement (in)equality tests but not
2501 the ordering operators (i.e. unordered types) should implement ==
2502 and !=, and raise an error for the ordering operators.
2503
Guido van Rossuma88479f2001-01-18 14:28:08 +00002504 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002505 Boolean; e.g. a matrix type might want to return a matrix of bits
2506 for A < B, giving elementwise comparisons. Such types should ensure
2507 that any interpretation of their value in a Boolean context raises
2508 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2509 at the C level) to always raise an exception.
2510
Guido van Rossuma88479f2001-01-18 14:28:08 +00002511- Complex numbers use rich comparisons to define == and != but raise
2512 an exception for <, <=, > and >=. Unfortunately, this also means
2513 that cmp() of two complex numbers raises an exception when the two
2514 numbers differ. Since it is not mathematically meaningful to compare
2515 complex numbers except for equality, I hope that this doesn't break
2516 too much code.
2517
Tim Peters3389f192001-02-18 08:48:49 +00002518- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002519 not defined by the language, other than that it's arbitrary but
2520 consistent (see the Reference Manual). An implementation detail changed
2521 in 2.1a1 such that None now compares less than any other object. Code
2522 relying on this new behavior (like code that relied on the previous
2523 behavior) does so at its own risk.
2524
Barry Warsaw573b5412001-01-15 20:43:18 +00002525- Functions and methods now support getting and setting arbitrarily
2526 named attributes (PEP 232). Functions have a new __dict__
2527 (a.k.a. func_dict) which hold the function attributes. Methods get
2528 and set attributes on their underlying im_func. It is a TypeError
2529 to set an attribute on a bound method.
2530
Guido van Rossum051e3352001-01-15 19:11:10 +00002531- The xrange() object implementation has been improved so that
2532 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2533 limitation that in this case len(xrange(sys.maxint)) can't be
2534 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2535 work fine as long as the index i doesn't actually reach 2**31.
2536 (Python uses regular ints for sequence and string indices; fixing
2537 that is much more work.)
2538
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002539- Two changes to from...import:
2540
Guido van Rossumba381232001-02-03 15:06:40 +00002541 1) "from M import X" now works even if (after loading module M)
2542 sys.modules['M'] is not a real module; it's basically a getattr()
2543 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002544
2545 2) "from M import *" now looks for M.__all__ to decide which names to
2546 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2547 filters out names starting with '_' as before. Whether or not
2548 __all__ exists, there's no restriction on the type of M.
2549
Guido van Rossumf61f1662001-01-10 20:13:55 +00002550- File objects have a new method, xreadlines(). This is the fastest
2551 way to iterate over all lines in a file:
2552
2553 for line in file.xreadlines():
2554 ...do something to line...
2555
2556 See the xreadlines module (mentioned below) for how to do this for
2557 other file-like objects.
2558
2559- Even if you don't use file.xreadlines(), you may expect a speedup on
2560 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002561 quite a bit in platform-specific ways: on systems (like Linux) that
2562 support flockfile(), getc_unlocked(), and funlockfile(), those are
2563 used by default. On systems (like Windows) without getc_unlocked(),
2564 a complicated (but still thread-safe) method using fgets() is used by
2565 default.
2566
Tim Petersd52269b2001-01-25 06:23:18 +00002567 You can force use of the fgets() method by #define'ing
2568 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002569 getc_unlocked()).
2570
Tim Petersd52269b2001-01-25 06:23:18 +00002571 You can force fgets() not to be used by #define'ing
2572 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002573 test_bufio.py fails -- and let us know if it does!).
2574
2575- In addition, the fileinput module, while still slower than the other
2576 methods on most platforms, has been sped up too, by using
2577 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002578
2579- Support for run-time warnings has been added, including a new
2580 command line option (-W) to specify the disposition of warnings.
2581 See the description of the warnings module below.
2582
2583- Extensive changes have been made to the coercion code. This mostly
2584 affects extension modules (which can now implement mixed-type
2585 numerical operators without having to use coercion), but
2586 occasionally, in boundary cases the coercion semantics have changed
2587 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002588 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002589 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002590 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002591
Guido van Rossumf98eda02001-01-17 15:54:45 +00002592- In connection with the coercion changes, a new built-in singleton
2593 object, NotImplemented is defined. This can be returned for
2594 operations that wish to indicate they are not implemented for a
2595 particular combination of arguments. From C, this is
2596 Py_NotImplemented.
2597
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002598- The interpreter accepts now bytecode files on the command line even
2599 if they do not have a .pyc or .pyo extension. On Linux, after executing
2600
Martin v. Löwise214baa2001-02-04 22:37:56 +00002601import imp,sys,string
2602magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2603reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2604open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002605
2606 any byte code file can be used as an executable (i.e. as an argument
2607 to execve(2)).
2608
Tim Peters9940b802000-12-01 07:59:35 +00002609- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002610 character. In 1.6 and earlier, they never produced a sign,
2611 and raised an error if the value of the long was too large
2612 to fit in a Python int. In 2.0, they produced a sign if and
2613 only if too large to fit in an int. This was inconsistent
2614 across platforms (because the size of an int varies across
2615 platforms), and inconsistent with hex() and oct(). Example:
2616
2617 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002618 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002619 'ffffffbe' # in 2.0 and before, on 32-bit machines
2620 >>> hex(-0x42L)
2621 '-0x42L' # in all versions of Python
2622
Tim Peters9940b802000-12-01 07:59:35 +00002623 The behavior of %d formats for negative Python longs remains
2624 the same as in 2.0 (although in 1.6 and before, they raised
2625 an error if the long didn't fit in a Python int).
2626
2627 %u formats don't make sense for Python longs, but are allowed
2628 and treated the same as %d in 2.1. In 2.0, a negative long
2629 formatted via %u produced a sign if and only if too large to
2630 fit in an int. In 1.6 and earlier, a negative long formatted
2631 via %u raised an error if it was too big to fit in an int.
2632
Guido van Rossum3661d392000-12-12 22:10:31 +00002633- Dictionary objects have an odd new method, popitem(). This removes
2634 an arbitrary item from the dictionary and returns it (in the form of
2635 a (key, value) pair). This can be useful for algorithms that use a
2636 dictionary as a bag of "to do" items and repeatedly need to pick one
2637 item. Such algorithms normally end up running in quadratic time;
2638 using popitem() they can usually be made to run in linear time.
2639
Tim Peters36cdad12000-12-29 02:06:45 +00002640Standard library
2641
Thomas Woutersfe385252001-01-19 23:16:56 +00002642- In the time module, the time argument to the functions strftime,
2643 localtime, gmtime, asctime and ctime is now optional, defaulting to
2644 the current time (in the local timezone).
2645
Guido van Rossumda91f222001-01-15 16:36:08 +00002646- The ftplib module now defaults to passive mode, which is deemed a
2647 more useful default given that clients are often inside firewalls
2648 these days. Note that this could break if ftplib is used to connect
2649 to a *server* that is inside a firewall, from outside; this is
2650 expected to be a very rare situation. To fix that, you can call
2651 ftp.set_pasv(0).
2652
Martin v. Löwis10a27872001-01-13 09:54:41 +00002653- The module site now treats .pth files not only for path configuration,
2654 but also supports extensions to the initialization code: Lines starting
2655 with import are executed.
2656
Guido van Rossumf61f1662001-01-10 20:13:55 +00002657- There's a new module, warnings, which implements a mechanism for
2658 issuing and filtering warnings. There are some new built-in
2659 exceptions that serve as warning categories, and a new command line
2660 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2661 turns warnings into errors). warnings.warn(message[, category])
2662 issues a warning message; this can also be called from C as
2663 PyErr_Warn(category, message).
2664
2665- A new module xreadlines was added. This exports a single factory
2666 function, xreadlines(). The intention is that this code is the
2667 absolutely fastest way to iterate over all lines in an open
2668 file(-like) object:
2669
2670 import xreadlines
2671 for line in xreadlines.xreadlines(file):
2672 ...do something to line...
2673
2674 This is equivalent to the previous the speed record holder using
2675 file.readlines(sizehint). Note that if file is a real file object
2676 (as opposed to a file-like object), this is equivalent:
2677
2678 for line in file.xreadlines():
2679 ...do something to line...
2680
Tim Peters36cdad12000-12-29 02:06:45 +00002681- The bisect module has new functions bisect_left, insort_left,
2682 bisect_right and insort_right. The old names bisect and insort
2683 are now aliases for bisect_right and insort_right. XXX_right
2684 and XXX_left methods differ in what happens when the new element
2685 compares equal to one or more elements already in the list: the
2686 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002687 right. Code that doesn't care where equal elements end up should
2688 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002689
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002690- The new curses.panel module wraps the panel library that forms part
2691 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2692
Guido van Rossumf61f1662001-01-10 20:13:55 +00002693- The SocketServer module now sets the allow_reuse_address flag by
2694 default in the TCPServer class.
2695
2696- A new function, sys._getframe(), returns the stack frame pointer of
2697 the caller. This is intended only as a building block for
2698 higher-level mechanisms such as string interpolation.
2699
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002700- The pyexpat module supports a number of new handlers, which are
2701 available only in expat 1.2. If invocation of a callback fails, it
2702 will report an additional frame in the traceback. Parser objects
2703 participate now in garbage collection. If expat reports an unknown
2704 encoding, pyexpat will try to use a Python codec; that works only
2705 for single-byte charsets. The parser type objects is exposed as
2706 XMLParserObject.
2707
2708- xml.dom now offers standard definitions for symbolic node type and
2709 exception code constants, and a hierarchy of DOM exceptions. minidom
2710 was adjusted to use them.
2711
2712- The conformance of xml.dom.minidom to the DOM specification was
2713 improved. It detects a number of additional error cases; the
2714 previous/next relationship works even when the tree is modified;
2715 Node supports the normalize() method; NamedNodeMap, DocumentType and
2716 DOMImplementation classes were added; Element supports the
2717 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2718 method.
2719
Guido van Rossumf61f1662001-01-10 20:13:55 +00002720Build issues
2721
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002722- For Unix (and Unix-compatible) builds, configuration and building of
2723 extension modules is now greatly automated. Rather than having to
2724 edit the Modules/Setup file to indicate which modules should be
2725 built and where their include files and libraries are, a
2726 distutils-based setup.py script now takes care of building most
2727 extension modules. All extension modules built this way are built
2728 as shared libraries. Only a few modules that must be linked
2729 statically are still listed in the Setup file; you won't need to
2730 edit their configuration.
2731
2732- Python should now build out of the box on Cygwin. If it doesn't,
2733 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002734
2735- Python now always uses its own (renamed) implementation of getopt()
2736 -- there's too much variation among C library getopt()
2737 implementations.
2738
2739- C++ compilers are better supported; the CXX macro is always set to a
2740 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002741
Tim Petersd92dfe02000-12-12 01:18:41 +00002742Windows changes
2743
2744- select module: By default under Windows, a select() call
2745 can specify no more than 64 sockets. Python now boosts
2746 this Microsoft default to 512. If you need even more than
2747 that, see the MS docs (you'll need to #define FD_SETSIZE
2748 and recompile Python from source).
2749
Guido van Rossumf61f1662001-01-10 20:13:55 +00002750- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2751 subdirectory is no more!
2752
Tim Petersa3a3a032000-11-30 05:22:44 +00002753
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002754What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002755=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002756
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002757Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002758changes are in the file HISTORY. If you are making the jump directly
2759from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2760HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002761
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002762Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2763the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2764http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002765
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002766--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002767
2768======================================================================
2769
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002770What's new in 2.0 (since release candidate 1)?
2771==============================================
2772
2773Standard library
2774
2775- The copy_reg module was modified to clarify its intended use: to
2776 register pickle support for extension types, not for classes.
2777 pickle() will raise a TypeError if it is passed a class.
2778
2779- Fixed a bug in gettext's "normalize and expand" code that prevented
2780 it from finding an existing .mo file.
2781
2782- Restored support for HTTP/0.9 servers in httplib.
2783
Tim Peters989b7b92000-10-16 20:24:53 +00002784- The math module was changed to stop raising OverflowError in case of
2785 underflow, and return 0 instead in underflow cases. Whether Python
2786 used to raise OverflowError in case of underflow was platform-
2787 dependent (it did when the platform math library set errno to ERANGE
2788 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002789
2790- Fixed a bug in StringIO that occurred when the file position was not
2791 at the end of the file and write() was called with enough data to
2792 extend past the end of the file.
2793
2794- Fixed a bug that caused Tkinter error messages to get lost on
2795 Windows. The bug was fixed by replacing direct use of
2796 interp->result with Tcl_GetStringResult(interp).
2797
2798- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2799 redirect response.
2800
2801- Several changes were made to distutils: Some debugging code was
2802 removed from util. Fixed the installer used when an external zip
2803 program (like WinZip) is not found; the source code for this
2804 installer is in Misc/distutils. check_lib() was modified to behave
2805 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2806 test for whether installed modules are on sys.path was changed to
2807 use both normcase() and normpath().
2808
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002809- Several minor bugs were fixed in the xml package (the minidom,
2810 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002811
2812- The regression test driver (regrtest.py) behavior when invoked with
2813 -l changed: It now reports a count of objects that are recognized as
2814 garbage but not freed by the garbage collector.
2815
Tim Peters989b7b92000-10-16 20:24:53 +00002816- The regression test for the math module was changed to test
2817 exceptional behavior when the test is run in verbose mode. Python
2818 cannot yet guarantee consistent exception behavior across platforms,
2819 so the exception part of test_math is run only in verbose mode, and
2820 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002821
2822Internals
2823
2824- PyOS_CheckStack() has been disabled on Win64, where it caused
2825 test_sre to fail.
2826
2827Build issues
2828
2829- Changed compiler flags, so that gcc is always invoked with -Wall and
2830 -Wstrict-prototypes. Users compiling Python with GCC should see
2831 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002832 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002833 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002834
Tim Petersa3a3a032000-11-30 05:22:44 +00002835- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002836
2837Tools and other miscellany
2838
2839- The compiler in Tools/compiler was updated to support the new
2840 language features introduced in 2.0: extended print statement, list
2841 comprehensions, and augmented assignments. The new compiler should
2842 also be backwards compatible with Python 1.5.2; the compiler will
2843 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002844 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002845
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002846What's new in 2.0 release candidate 1 (since beta 2)?
2847=====================================================
2848
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002849What is release candidate 1?
2850
2851We believe that release candidate 1 will fix all known bugs that we
2852intend to fix for the 2.0 final release. This release should be a bit
2853more stable than the previous betas. We would like to see even more
2854widespread testing before the final release, so we are producing this
2855release candidate. The final release will be exactly the same unless
2856any show-stopping (or brown bag) bugs are found by testers of the
2857release candidate.
2858
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002859All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002860to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002861
2862Core language, builtins, and interpreter
2863
2864- A bug that caused crashes when __coerce__ was used with augmented
2865 assignment, e.g. +=, was fixed.
2866
2867- Raise ZeroDivisionError when raising zero to a negative number,
2868 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2869 power operator and the result of math.pow(0.0, -2.0) will vary by
2870 platform. On Linux, it raises a ValueError.
2871
2872- A bug in Unicode string interpolation was fixed that occasionally
2873 caused errors with formats including "%%". For example, the
2874 following expression "%% %s" % u"abc" no longer raises a TypeError.
2875
2876- Compilation of deeply nested expressions raises MemoryError instead
2877 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2878
2879- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2880 rendering them useless. They are now written in binary mode again.
2881
2882Standard library
2883
2884- Keyword arguments are now accepted for most pattern and match object
2885 methods in SRE, the standard regular expression engine.
2886
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002887- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002888 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002889
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002890- Several bugs in the Unicode handling and error handling in _tkinter
2891 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002892
2893- Fix memory management errors in Merge() and Tkapp_Call() routines.
2894
2895- Several changes were made to cStringIO to make it compatible with
2896 the file-like object interface and with StringIO. If operations are
2897 performed on a closed object, an exception is raised. The truncate
2898 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002899 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002900
2901- There were many changes made to the linuxaudiodev module and its
2902 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002903 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002904
2905 Note that this module is named poorly, because it should work
2906 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002907 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002908
2909 The module now raises exceptions when errors occur instead of
2910 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2911 audio) and defines a getptr() method that calls the
2912 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2913
2914- The library_version attribute, introduced in an earlier beta, was
2915 removed because it can not be supported with early versions of the C
2916 readline library, which provides no way to determine the version at
2917 compile-time.
2918
2919- The binascii module is now enabled on Win64.
2920
Tim Peters46446d62000-10-09 21:19:31 +00002921- tokenize.py no longer suffers "recursion depth" errors when parsing
2922 programs with very long string literals.
2923
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002924Internals
2925
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002926- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002927 which is called when the interpreter starts up to determine where
2928 the standard library is installed. These vulnerabilities affect all
2929 previous versions of Python and can be exploited by setting very
2930 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2931 setuid Python script, although use of the wrapper in
2932 Misc/setuid-prog.c will eliminate the vulnerability.
2933
2934- Fixed garbage collection bugs in instance creation that were
2935 triggered when errors occurred during initialization. The solution,
2936 applied in cPickle and in PyInstance_New(), is to call
2937 PyObject_GC_Init() after the initialization of the object's
2938 container attributes is complete.
2939
2940- pyexpat adds definitions of PyModule_AddStringConstant and
2941 PyModule_AddObject if the Python version is less than 2.0, which
2942 provides compatibility with PyXML on Python 1.5.2.
2943
2944- If the platform has a bogus definition for LONG_BIT (the number of
2945 bits in a long), an error will be reported at compile time.
2946
2947- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2948 collection crashes and possibly other, unreported crashes.
2949
2950- Fixed a memory leak in _PyUnicode_Fini().
2951
2952Build issues
2953
2954- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002955 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002956 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002957
2958- The mmap.PAGESIZE constant is now initialized using sysconf when
2959 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2960
2961- The md5 file should now compile on all platforms.
2962
2963- The select module now compiles on platforms that do not define
2964 POLLRDNORM and related constants.
2965
2966- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002967 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002968
Jeremy Hylton10921202000-10-09 18:34:12 +00002969- BeOS: A number of changes were made to the build and installation
2970 process. ar-fake now operates on a directory of object files.
2971 dl_export.h is gone, and its macros now appear on the mwcc command
2972 line during build on PPC BeOS.
2973
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002974- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002975 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002976
2977- Cygwin: Support for shared libraries, Tkinter, and sockets.
2978
2979- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2980
2981Tools and other miscellany
2982
2983- Removed debugging prints from main used with freeze.
2984
Tim Peters46446d62000-10-09 21:19:31 +00002985- IDLE auto-indent no longer crashes when it encounters Unicode
2986 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002987
2988What's new in 2.0 beta 2 (since beta 1)?
2989========================================
2990
2991Core language, builtins, and interpreter
2992
Tim Peters482c0212000-09-26 06:33:09 +00002993- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002994 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002995
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002996- Add -h and -V command line options to print the usage message and
2997 Python version number and exit immediately.
2998
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002999- eval() and exec accept Unicode objects as code parameters.
3000
3001- getattr() and setattr() now also accept Unicode objects for the
3002 attribute name, which are converted to strings using the default
3003 encoding before lookup.
3004
3005- Multiplication on string and Unicode now does proper bounds
3006 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
3007 string is too long."
3008
3009- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00003010 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003011
Jeremy Hylton1b618592000-09-26 05:32:36 +00003012
3013Standard library and extensions
3014
Guido van Rossum5b08f132001-04-16 02:05:23 +00003015- socket module: the OpenSSL code now adds support for RAND_status()
3016 and EGD (Entropy Gathering Device).
3017
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003018- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00003019 argument checking; it still takes no arguments.
3020
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003021- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003022
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003023- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003024
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003025- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003026
3027- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003028 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003029
3030- copy: Copy Unicode objects atomically.
3031
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003032- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003033
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003034- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003035
Fred Drake67233bc2000-09-26 16:40:27 +00003036- dbm: Add get() and setdefault() methods to dbm object. Add constant
3037 `library' to module that names the library used. Added doc strings
3038 and method names to error messages. Uses configure to determine
3039 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
3040 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003041
3042- distutils: Update to version 0.9.3.
3043
3044- dl: Add several dl.RTLD_ constants.
3045
3046- fpectl: Now supported on FreeBSD.
3047
3048- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
3049 found by the collector will be saved in gc.garbage. This is useful
3050 for debugging a program that creates reference cycles.
3051
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003052- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003053 of HTTP class. Do not close socket on zero-length response. Do not
3054 crash when server sends invalid content-length header.
3055
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003056- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003057
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003058- marshal: When reading a short, sign-extend on platforms where shorts
3059 are bigger than 16 bits. When reading a long, repair the unportable
3060 sign extension that was being done for 64-bit machines. (It assumed
3061 that signed right shift sign-extends.)
3062
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003063- operator: Add contains(), invert(), __invert__() as aliases for
3064 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003065
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003066- os: Add support for popen2() and popen3() on all platforms where
3067 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003068
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003069- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003070 clicking on a file in Explorer (or passing the file name to the
3071 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003072
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003073- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003074 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003075
3076- pickle: Now raises ValueError when an invalid pickle that contains
3077 a non-string repr where a string repr was expected. This behavior
3078 matches cPickle.
3079
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003080- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003081
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003082- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003083
3084- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003085 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003086 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003087
3088- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003089 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003090
3091- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003092 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003093 few cycles during startup since the first call to
3094 setdefaultencoding() will initialize the codec registry and the
3095 encodings package.
3096
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003097- socket: Support for size hint in readlines() method of object returned
3098 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003099
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003100- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003101 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003102 is followed by whitespace.
3103
Tim Petersa3a3a032000-11-30 05:22:44 +00003104- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003105
3106- struct: Check ranges for bytes and shorts.
3107
3108- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003109 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003110
3111- Tkinter: Image objects are now guaranteed to have unique ids. Set
3112 event.delta to zero if Tk version doesn't support mousewheel.
3113 Removed some debugging prints.
3114
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003115- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003116
Fred Drake67233bc2000-09-26 16:40:27 +00003117- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003118 which works around a bug in Norton AntiVirus 2000 that leads directly
3119 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003120
3121- xml: New version detection code allows PyXML to override standard
3122 XML package if PyXML version is greater than 0.6.1.
3123
Fred Drake64bb3802000-09-26 16:21:35 +00003124- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3125 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3126 tree only for nodes which are sufficiently interesting to a specific
3127 application. Does not provide the HTML-specific extensions. Still
3128 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003129
Fred Drake64bb3802000-09-26 16:21:35 +00003130- xml.sax: SAX 2 support for Python, including all the handler
3131 interfaces needed to process XML 1.0 compliant XML. Some
3132 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003133
Fred Drake64bb3802000-09-26 16:21:35 +00003134- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3135 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003136
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003137
Jeremy Hylton1b618592000-09-26 05:32:36 +00003138C API
3139
3140- Add three new convenience functions for module initialization --
3141 PyModule_AddObject(), PyModule_AddIntConstant(), and
3142 PyModule_AddStringConstant().
3143
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003144- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003145 removed and add #error to Python.h if NULL isn't defined after
3146 #include of stdio.h.
3147
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003148- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003149 backwards compatibility (at the source level) with old extensions.
3150
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003151- A wrapper API was added for signal() and sigaction(). Instead of
3152 either function, always use PyOS_getsig() to get a signal handler
3153 and PyOS_setsig() to set one. A new convenience typedef
3154 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003155
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003156- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003157 internal data buffer and size of a string object -- or the default
3158 encoded version of a Unicode object.
3159
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003160- PyString_Size() and PyString_AsString() accept Unicode objects.
3161
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003162- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003163 exists). INT_MAX and LONG_MAX will always be defined, even if
3164 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003165
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003166- PyFloat_FromString takes a second argument, pend, that was
3167 effectively useless. It is now officially useless but preserved for
3168 backwards compatibility. If the pend argument is not NULL, *pend is
3169 set to NULL.
3170
3171- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3172 for the attribute name. See note on getattr() above.
3173
3174- A few bug fixes to argument processing for Unicode.
3175 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3176 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3177 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003178 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003179
3180- Py_BuildValue accepts B format (for bgen-generated code).
3181
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003182
Jeremy Hylton1b618592000-09-26 05:32:36 +00003183Internals
3184
3185- On Unix, fix code for finding Python installation directory so that
3186 it works when argv[0] is a relative path.
3187
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003188- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003189 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003190 rather than by generating a copy of the object.
3191
Tim Peters482c0212000-09-26 06:33:09 +00003192- Several of the internal Unicode tables are much smaller now, and
3193 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003194
Jeremy Hylton97693b02000-09-26 17:42:51 +00003195- In the garbage collector: Fixed bug in collection of tuples. Fixed
3196 bug that caused some instances to be removed from the container set
3197 while they were still live. Fixed parsing in gc.set_debug() for
3198 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003199
3200- Fixed refcount problem in instance deallocation that only occurred
3201 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3202
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003203- On Windows, getpythonregpath is now protected against null data in
3204 registry key.
3205
3206- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003207 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003208
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003209
Jeremy Hylton1b618592000-09-26 05:32:36 +00003210Build and platform-specific issues
3211
3212- Better support of GNU Pth via --with-pth configure option.
3213
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003214- Python/C API now properly exposed to dynamically-loaded extension
3215 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003216
3217- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3218 Don't define MS_SYNC to be zero when it is undefined. Added missing
3219 prototypes in posixmodule.c.
3220
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003221- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003222 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003223
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003224- Fix largefile support on older NetBSD systems and OpenBSD by adding
3225 define for TELL64.
3226
3227
3228Tools and other miscellany
3229
3230- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3231
3232- freeze: The modulefinder now works with 2.0 opcodes.
3233
Tim Petersa3a3a032000-11-30 05:22:44 +00003234- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003235 Move hackery of sys.argv until after the Tk instance has been
3236 created, which allows the application-specific Tkinter
3237 initialization to be executed if present; also pass an explicit
3238 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003239
Jeremy Hylton1b618592000-09-26 05:32:36 +00003240
3241What's new in 2.0 beta 1?
3242=========================
3243
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003244Source Incompatibilities
3245------------------------
3246
3247None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3248such as single-argument append(), connect() and bind(), and changes to
3249str(long) and repr(float).
3250
3251
3252Binary Incompatibilities
3253------------------------
3254
3255- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3256with Python 2.0; these extensions will have to be rebuilt for Python
32572.0.
3258
3259- On Windows, attempting to import a third party extension built for
3260Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3261can do about this. Check your PYTHONPATH environment variable!
3262
3263- Python bytecode files (*.pyc and *.pyo) are not compatible between
3264releases.
3265
3266
3267Overview of Changes Since 1.6
3268-----------------------------
3269
3270There are many new modules (including brand new XML support through
3271the xml package, and i18n support through the gettext module); a list
3272of all new modules is included below. Lots of bugs have been fixed.
3273
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003274The process for making major new changes to the language has changed
3275since Python 1.6. Enhancements must now be documented by a Python
3276Enhancement Proposal (PEP) before they can be accepted.
3277
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003278There are several important syntax enhancements, described in more
3279detail below:
3280
3281 - Augmented assignment, e.g. x += 1
3282
3283 - List comprehensions, e.g. [x**2 for x in range(10)]
3284
3285 - Extended import statement, e.g. import Module as Name
3286
3287 - Extended print statement, e.g. print >> file, "Hello"
3288
3289Other important changes:
3290
3291 - Optional collection of cyclical garbage
3292
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003293Python Enhancement Proposal (PEP)
3294---------------------------------
3295
3296PEP stands for Python Enhancement Proposal. A PEP is a design
3297document providing information to the Python community, or describing
3298a new feature for Python. The PEP should provide a concise technical
3299specification of the feature and a rationale for the feature.
3300
3301We intend PEPs to be the primary mechanisms for proposing new
3302features, for collecting community input on an issue, and for
3303documenting the design decisions that have gone into Python. The PEP
3304author is responsible for building consensus within the community and
3305documenting dissenting opinions.
3306
3307The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003308
3309Augmented Assignment
3310--------------------
3311
3312This must have been the most-requested feature of the past years!
3313Eleven new assignment operators were added:
3314
Guido van Rossume905e952000-09-05 12:42:46 +00003315 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003316
3317For example,
3318
3319 A += B
3320
3321is similar to
3322
3323 A = A + B
3324
3325except that A is evaluated only once (relevant when A is something
3326like dict[index].attr).
3327
3328However, if A is a mutable object, A may be modified in place. Thus,
3329if A is a number or a string, A += B has the same effect as A = A+B
3330(except A is only evaluated once); but if a is a list, A += B has the
3331same effect as A.extend(B)!
3332
3333Classes and built-in object types can override the new operators in
3334order to implement the in-place behavior; the not-in-place behavior is
3335used automatically as a fallback when an object doesn't implement the
3336in-place behavior. For classes, the method name is derived from the
3337method name for the corresponding not-in-place operator by inserting
3338an 'i' in front of the name, e.g. __iadd__ implements in-place
3339__add__.
3340
3341Augmented assignment was implemented by Thomas Wouters.
3342
3343
3344List Comprehensions
3345-------------------
3346
3347This is a flexible new notation for lists whose elements are computed
3348from another list (or lists). The simplest form is:
3349
3350 [<expression> for <variable> in <sequence>]
3351
Guido van Rossum56db0952000-09-06 23:34:25 +00003352For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003353This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003354
3355You can also add a condition:
3356
3357 [<expression> for <variable> in <sequence> if <condition>]
3358
3359For example, [w for w in words if w == w.lower()] would yield the list
3360of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003361than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003362
3363You can also have nested for loops and more than one 'if' clause. For
3364example, here's a function that flattens a sequence of sequences::
3365
3366 def flatten(seq):
3367 return [x for subseq in seq for x in subseq]
3368
3369 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3370
3371This prints
3372
3373 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3374
3375List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003376Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003377
3378
3379Extended Import Statement
3380-------------------------
3381
3382Many people have asked for a way to import a module under a different
3383name. This can be accomplished like this:
3384
3385 import foo
3386 bar = foo
3387 del foo
3388
3389but this common idiom gets old quickly. A simple extension of the
3390import statement now allows this to be written as follows:
3391
3392 import foo as bar
3393
3394There's also a variant for 'from ... import':
3395
3396 from foo import bar as spam
3397
3398This also works with packages; e.g. you can write this:
3399
3400 import test.regrtest as regrtest
3401
3402Note that 'as' is not a new keyword -- it is recognized only in this
3403context (this is only possible because the syntax for the import
3404statement doesn't involve expressions).
3405
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003406Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003407
3408
3409Extended Print Statement
3410------------------------
3411
3412Easily the most controversial new feature, this extension to the print
3413statement adds an option to make the output go to a different file
3414than the default sys.stdout.
3415
3416For example, to write an error message to sys.stderr, you can now
3417write:
3418
3419 print >> sys.stderr, "Error: bad dog!"
3420
3421As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003422evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003423
3424 print >> None, "Hello world"
3425
3426is equivalent to
3427
3428 print "Hello world"
3429
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003430Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003431
3432
3433Optional Collection of Cyclical Garbage
3434---------------------------------------
3435
3436Python is now equipped with a garbage collector that can hunt down
3437cyclical references between Python objects. It's no replacement for
3438reference counting; in fact, it depends on the reference counts being
3439correct, and decides that a set of objects belong to a cycle if all
3440their reference counts can be accounted for from their references to
3441each other. This devious scheme was first proposed by Eric Tiedemann,
3442and brought to implementation by Neil Schemenauer.
3443
3444There's a module "gc" that lets you control some parameters of the
3445garbage collection. There's also an option to the configure script
3446that lets you enable or disable the garbage collection. In 2.0b1,
3447it's on by default, so that we (hopefully) can collect decent user
3448experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003449performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003450off by default in the final 2.0 release.
3451
3452
3453Smaller Changes
3454---------------
3455
3456A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3457map(None, seq1, seq2, ...) when the sequences have the same length;
3458i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3459the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003460zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003461
3462sys.version_info is a tuple (major, minor, micro, level, serial).
3463
3464Dictionaries have an odd new method, setdefault(key, default).
3465dict.setdefault(key, default) returns dict[key] if it exists; if not,
3466it sets dict[key] to default and returns that value. Thus:
3467
3468 dict.setdefault(key, []).append(item)
3469
3470does the same work as this common idiom:
3471
3472 if not dict.has_key(key):
3473 dict[key] = []
3474 dict[key].append(item)
3475
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003476There are two new variants of SyntaxError that are raised for
3477indentation-related errors: IndentationError and TabError.
3478
3479Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3480escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003481
3482The limits on the size of expressions and file in Python source code
3483have been raised from 2**16 to 2**32. Previous versions of Python
3484were limited because the maximum argument size the Python VM accepted
3485was 2**16. This limited the size of object constructor expressions,
3486e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3487limit was raised thanks to a patch by Charles Waldman that effectively
3488fixes the problem. It is now much more likely that you will be
3489limited by available memory than by an arbitrary limit in Python.
3490
3491The interpreter's maximum recursion depth can be modified by Python
3492programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3493limit is the maximum number of recursive calls that can be made by
3494Python code. The limit exists to prevent infinite recursion from
3495overflowing the C stack and causing a core dump. The default value is
34961000. The maximum safe value for a particular platform can be found
3497by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003498
3499New Modules and Packages
3500------------------------
3501
3502atexit - for registering functions to be called when Python exits.
3503
3504imputil - Greg Stein's alternative API for writing custom import
3505hooks.
3506
3507pyexpat - an interface to the Expat XML parser, contributed by Paul
3508Prescod.
3509
3510xml - a new package with XML support code organized (so far) in three
3511subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3512would fill a volume. There's a special feature whereby a
3513user-installed package named _xmlplus overrides the standard
3514xmlpackage; this is intended to give the XML SIG a hook to distribute
3515backwards-compatible updates to the standard xml package.
3516
3517webbrowser - a platform-independent API to launch a web browser.
3518
3519
Guido van Rossume905e952000-09-05 12:42:46 +00003520Changed Modules
3521---------------
3522
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003523array -- new methods for array objects: count, extend, index, pop, and
3524remove
3525
3526binascii -- new functions b2a_hex and a2b_hex that convert between
3527binary data and its hex representation
3528
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003529calendar -- Many new functions that support features including control
3530over which day of the week is the first day, returning strings instead
3531of printing them. Also new symbolic constants for days of week,
3532e.g. MONDAY, ..., SUNDAY.
3533
3534cgi -- FieldStorage objects have a getvalue method that works like a
3535dictionary's get method and returns the value attribute of the object.
3536
3537ConfigParser -- The parser object has new methods has_option,
3538remove_section, remove_option, set, and write. They allow the module
3539to be used for writing config files as well as reading them.
3540
3541ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003542optionally support the RFC 959 REST command.
3543
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003544gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003545
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003546httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3547the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003548
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003549locale -- implement getdefaultlocale for Win32 and Macintosh
3550
3551marshal -- no longer dumps core when marshaling deeply nested or
3552recursive data structures
3553
3554os -- new functions isatty, seteuid, setegid, setreuid, setregid
3555
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003556os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3557support under Unix.
3558
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003559os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003560
3561os.path -- fix semantics of os.path.commonprefix
3562
3563smtplib -- support for sending very long messages
3564
3565socket -- new function getfqdn()
3566
3567readline -- new functions to read, write and truncate history files.
3568The readline section of the library reference manual contains an
3569example.
3570
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003571select -- add interface to poll system call
3572
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003573shutil -- new copyfileobj function
3574
3575SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3576HTTP server.
3577
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003578Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003579
3580urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003581e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003582
3583whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003584
3585
3586Obsolete Modules
3587----------------
3588
3589None. However note that 1.6 made a whole slew of modules obsolete:
3590stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3591poly, zmod, strop, util, whatsound.
3592
3593
3594Changed, New, Obsolete Tools
3595----------------------------
3596
Tim Peters8b092332000-09-05 20:15:25 +00003597None.
Guido van Rossume905e952000-09-05 12:42:46 +00003598
3599
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003600C-level Changes
3601---------------
3602
3603Several cleanup jobs were carried out throughout the source code.
3604
3605All C code was converted to ANSI C; we got rid of all uses of the
3606Py_PROTO() macro, which makes the header files a lot more readable.
3607
3608Most of the portability hacks were moved to a new header file,
3609pyport.h; several other new header files were added and some old
3610header files were removed, in an attempt to create a more rational set
3611of header files. (Few of these ever need to be included explicitly;
3612they are all included by Python.h.)
3613
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003614Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003615and Win64, especially for the new Intel Itanium processor. Mick also
3616added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003617
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003618The C APIs to return an object's size have been update to consistently
3619use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3620previous versions, the abstract interfaces used PyXXX_Length and the
3621concrete interfaces used PyXXX_Size. The old names,
3622e.g. PyObject_Length, are still available for backwards compatibility
3623at the API level, but are deprecated.
3624
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003625The PyOS_CheckStack function has been implemented on Windows by
3626Fredrik Lundh. It prevents Python from failing with a stack overflow
3627on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003628
3629The GC changes resulted in creation of two new slots on object,
3630tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003631the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003632
3633The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003634C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003635
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003636PyErr_Format has been updated to automatically calculate the size of
3637the buffer needed to hold the formatted result string. This change
3638prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003639
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003640New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003641
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003642PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3643that are the same as their non-Ex counterparts except they take an
3644extra flag argument that tells them to close the file when done.
3645
3646XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003647
Tim Peters8b092332000-09-05 20:15:25 +00003648
3649Windows Changes
3650---------------
3651
3652New popen2/popen3/peopen4 in os module (see Changed Modules above).
3653
3654os.popen is much more usable on Windows 95 and 98. See Microsoft
3655Knowledge Base article Q150956. The Win9x workaround described there
3656is implemented by the new w9xpopen.exe helper in the root of your
3657Python installation. Note that Python uses this internally; it is not
3658a standalone program.
3659
3660Administrator privileges are no longer required to install Python
3661on Windows NT or Windows 2000. If you have administrator privileges,
3662Python's registry info will be written under HKEY_LOCAL_MACHINE.
3663Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003664under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003665uses of Python, but will prevent some advanced uses from working
3666(for example, running a Python script as an NT service, or possibly
3667from CGI).
3668
3669[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3670installer; instead, it installs the needed Tcl/Tk files directly in the
3671Python directory. If you already have a Tcl/Tk installation, this
3672wastes some disk space (about 4 Megs) but avoids problems with
3673conflicting Tcl/Tk installations, and makes it much easier for Python
3674to ensure that Tcl/Tk can find all its files.
3675
3676[This was new in 1.6] The Windows installer now installs by default in
3677\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3678
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003679
3680Updates to the changes between 1.5.2 and 1.6
3681--------------------------------------------
3682
3683The 1.6 NEWS file can't be changed after the release is done, so here
3684is some late-breaking news:
3685
3686New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3687and changes to getlocale() and setlocale().
3688
3689The new module is now enabled per default.
3690
3691It is not true that the encodings codecs cannot be used for normal
3692strings: the string.encode() (which is also present on 8-bit strings
3693!) allows using them for 8-bit strings too, e.g. to convert files from
3694cp1252 (Windows) to latin-1 or vice-versa.
3695
3696Japanese codecs are available from Tamito KAJIYAMA:
3697http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3698
3699
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003700======================================================================