blob: f3971617a471b231a90a42fcfcb5efaea700426b [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
Barry Warsawd79f6832002-08-06 17:01:51 +00009- Previously, "str1 in str2" required str1 to be a string of length 1.
10 This restriction has been relaxed to allow str1 to be a string of
11 any length. Thus "'el' in 'hello world'" returns True now.
12
Guido van Rossumb57089c2002-08-06 16:20:26 +000013- File objects are now their own iterators. For a file f, iter(f) now
14 returns f (unless f is closed), and f.next() is similar to
15 f.readline() when EOF is not reached; however, f.next() uses a
16 readahead buffer that messes up the file position, so mixing
17 f.next() and f.readline() (or other methods) doesn't work right.
18 Calling f.seek() drops the readahead buffer, but other operations
19 don't. It so happens that this gives a nice additional speed boost
20 to "for line in file:"; the xreadlines method and corresponding
21 module are now obsolete.
22
Guido van Rossumde392d32002-08-05 14:17:20 +000023- Encoding declarations (PEP 263, phase 1) have been implemented. A
24 comment of the form "# -*- coding: <encodingname> -*-" in the first
25 or second line of a Python source file indicates the encoding.
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +000026
Tim Petersf47630f2002-08-01 02:34:51 +000027- list.sort() has a new implementation. While cross-platform results
28 may vary, and in data-dependent ways, this is much faster on many
29 kinds of partially ordered lists than the previous implementation,
30 and reported to be just as fast on randomly ordered lists on
31 several major platforms. This sort is also stable (if A==B and A
32 precedes B in the list at the start, A precedes B after the sort too),
33 although the language definition does not guarantee stability. A
34 potential drawback is that list.sort() may require temp space of
35 len(list)*2 bytes (*4 on a 64-bit machine). It's therefore possible
36 for list.sort() to raise MemoryError now, even if a comparison function
37 does not. See <http://www.python.org/sf/587076> for full details.
38
Guido van Rossum2d5389c2002-07-23 03:44:35 +000039- All standard iterators now ensure that, once StopIteration has been
40 raised, all future calls to next() on the same iterator will also
41 raise StopIteration. There used to be various counterexamples to
42 this behavior, which could caused confusion or subtle program
43 breakage, without any benefits. (Note that this is still an
44 iterator's responsibility; the iterator framework does not enforce
45 this.)
46
Mark Hammondc0e35152002-07-16 01:32:30 +000047- Ctrl+C handling on Windows has been made more consistent with
48 other platforms. KeyboardInterrupt can now reliably be caught,
Tim Petersf47630f2002-08-01 02:34:51 +000049 and Ctrl+C at an interative prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +000050 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Petersf47630f2002-08-01 02:34:51 +000051 interrupt time.sleep() in the main thread, and any child processes
52 created via the popen family are also interrupted (as generally
Mark Hammondc0e35152002-07-16 01:32:30 +000053 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
54
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000055- Slices and repetitions of buffer objects now consistently return
56 a string. Formerly, strings would be returned most of the time,
57 but a buffer object would be returned when the repetition count
58 was one or when the slice range was all inclusive.
59
Guido van Rossumc7c36502002-06-21 01:29:25 +000060- The __slots__ variable can now mention "private" names, and the
61 right thing will happen (e.g. __slots__ = ["__foo"]).
62
Walter Dörwald3430d702002-06-17 10:43:59 +000063- Unicode objects in sys.path are no longer ignored but treated
64 as directory names.
65
Guido van Rossum9562bcf2002-06-14 21:31:18 +000066- The built-ins slice() and buffer() are now callable types. The
67 types classobj (formerly class), code, function, instance, and
68 instancemethod (formerly instance-method), which have no built-in
69 names but are accessible through the types module, are now also
70 callable. The type dict-proxy is renamed to dictproxy.
71
Neal Norwitz1f68fc72002-06-14 00:50:42 +000072- Fixed string.startswith and string.endswith builtin methods
73 so they accept negative indices. [SF bug 493951]
74
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000075- Fixed a bug with a continue inside a try block and a yield in the
76 finally clause. [SF bug 567538]
77
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000078- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000079 with a third "stride" parameter. For example, "hello world"[::-1]
80 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000081
Guido van Rossum9f7549b2002-06-10 21:39:42 +000082- Cycles going through the __class__ link of a new-style instance are
83 now detected by the garbage collector.
84
Guido van Rossum9923ffe2002-06-04 19:52:53 +000085- Classes using __slots__ are now properly garbage collected.
86 [SF bug 519621]
87
88- Tightened the __slots__ rules: a slot name must be a valid Python
89 identifier.
90
Guido van Rossum2e4e0262002-06-04 05:58:34 +000091- The constructor for the module type now requires a name argument and
92 takes an optional docstring argument. Previously, this constructor
93 ignored its arguments. As a consequence, deriving a class from a
94 module (not from the module type) is now illegal; previously this
95 created an unnamed module, just like invoking the module type did.
96 [SF bug 563060]
97
Neal Norwitzd68f5172002-05-29 15:54:55 +000098- A new warning PendingDeprecationWarning was added to provide
99 direction on features which are in the process of being deprecated.
100 The warning will not be printed by default. To see the pending
101 deprecations, use -Walways::PendingDeprecationWarning::
102 as a command line option or warnings.filterwarnings() in code.
103
Neal Norwitz32a7e7f2002-05-31 19:58:02 +0000104- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +0000105 for 'str' and 'unicode', and can be used instead of
106 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +0000107 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +0000108 is an abstract base class and cannot be instantiated directly.
109
Fred Draked0ba6362002-05-02 21:28:26 +0000110- Deprecated features of xrange objects have been removed as
111 promised. The start, stop, and step attributes and the tolist()
112 method no longer exist. xrange repetition and slicing have been
113 removed.
114
Guido van Rossum7dab2422002-04-26 19:40:56 +0000115- New builtin function enumerate(x), from PEP 279. Example:
116 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
117 The argument can be an arbitrary iterable object.
118
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000119- The assert statement no longer tests __debug__ at runtime. This means
120 that assert statements cannot be disabled by assigning a false value
121 to __debug__.
122
Walter Dörwald068325e2002-04-15 13:36:47 +0000123- A method zfill() was added to str and unicode, that fills a numeric
124 string to the left with zeros. For example,
125 "+123".zfill(6) -> "+00123".
126
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000127- Complex numbers supported divmod() and the // and % operators, but
128 these make no sense. Since this was documented, they're being
129 deprecated now.
130
Guido van Rossum26dd8302002-04-26 20:11:29 +0000131- String and unicode methods lstrip(), rstrip() and strip() now take
132 an optional argument that specifies the characters to strip. For
133 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000134
Guido van Rossumc69343b2002-04-12 19:22:48 +0000135- Added a new dict method pop(key). This removes and returns the
136 value corresponding to key. [SF patch #539949]
137
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000138- Changed new-style class instantiation so that when C's __new__
139 method returns something that's not a C instance, its __init__ is
140 not called. [SF bug #537450]
141
Guido van Rossum181e41a2002-04-06 00:23:25 +0000142- Fixed super() to work correctly with class methods. [SF bug #535444]
143
Guido van Rossum47834462002-04-04 15:21:33 +0000144- A new built-in type, bool, has been added, as well as built-in
145 names for its two values, True and False. Comparisons and sundry
146 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000147 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000148 is backward compatible.
149
Guido van Rossum95b62a62002-03-29 01:07:24 +0000150- Fixed two bugs reported as SF #535905: under certain conditions,
151 deallocating a deeply nested structure could cause a segfault in the
152 garbage collector, due to interaction with the "trashcan" code;
153 access to the current frame during destruction of a local variable
154 could access a pointer to freed memory.
155
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000156- The optional object allocator ("pymalloc") has been enabled by
157 default. The recommended practice for memory allocation and
158 deallocation has been streamlined. A header file is included,
159 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
160 and lets them use the same API with Python versions from 1.5.2
161 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000162
Guido van Rossum8c842552002-03-14 23:05:54 +0000163- If you try to pickle an instance of a class that has __slots__ but
164 doesn't define or override __getstate__, a TypeError is now raised.
165 This is done by adding a bozo __getstate__ to the class that always
166 raises TypeError. (Before, this would appear to be pickled, but the
167 state of the slots would be lost.)
168
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000169- PyErr_Display will provide file and line information for all exceptions
170 that have an attribute print_file_and_line, not just SyntaxErrors.
171
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000172- The UTF-8 codec will now encode and decode Unicode surrogates
173 correctly and without raising exceptions for unpaired ones.
174
Neal Norwitz649b7592002-01-01 19:07:13 +0000175- file.xreadlines() now raises a ValueError if the file is closed:
176 Previously, an xreadlines object was returned which would raise
177 a ValueError when the xreadlines.next() method was called.
178
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000179- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000180 An exception will now be raised if more than one argument is used.
181
Tim Petersaf8446f2001-12-21 21:36:50 +0000182Extension modules
183
Guido van Rossumb57089c2002-08-06 16:20:26 +0000184- The xreadlines module is slated for obsolescence.
185
Guido van Rossum79f0a102002-07-23 03:32:08 +0000186- The strptime function in the time module is now always available (a
187 Python implementation is used when the C library doesn't define it).
188
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000189- The 'new' module is no longer an extension, but a Python module that
190 only exists for backwards compatibility. Its contents are no longer
191 functions but callable type objects.
192
Tim Peters81b92512002-04-29 01:37:32 +0000193- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000194 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000195 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000196
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000197- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
198 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000199
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000200- The locale module now exposes the C library's gettext interface.
201
Tim Petersfbf74f22002-03-14 19:06:01 +0000202- A security hole ("double free") was found in zlib-1.1.3, a popular
203 third party compression library used by some Python modules. The
204 hole was quickly plugged in zlib-1.1.4, and the Windows build of
205 Python now ships with zlib-1.1.4.
206
Martin v. Löwis688357e2002-04-08 21:28:20 +0000207- pwd, grp, and resource return enhanced tuples now, with symbolic
208 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000209
Martin v. Löwis99866332002-03-01 10:27:01 +0000210- array.array is now a type object. A new format character
211 'u' indicates Py_UNICODE arrays. For those, .tounicode and
212 .fromunicode methods are available. Arrays now support __iadd__
213 and __imul__.
214
Neal Norwitze790eae2002-01-01 21:14:12 +0000215- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000216 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
217 is called.
218
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000219- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
220 been added where available.
221
Tim Petersaf8446f2001-12-21 21:36:50 +0000222Library
223
Guido van Rossum4a57c332002-08-02 18:05:20 +0000224- New "algorithms" module: heapq, implements a heap queue. Thanks to
225 Kevin O'Connor for the code and François Pinard for an entertaining
226 write-up explaining the theory and practical uses of heaps.
227
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000228- New encoding for the Palm OS character set: palmos.
229
Tim Peters943382c2002-07-07 03:59:34 +0000230- binascii.crc32() and the zipfile module had problems on some 64-bit
231 platforms. These have been fixed. On a platform with 8-byte C longs,
232 crc32() now returns a signed-extended 4-byte result, so that its value
233 as a Python int is equal to the value computed a 32-bit platform.
234
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000235- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
236 argument.
237
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000238- Some fixes in the copy module: when an object is copied through its
239 __reduce__ method, there was no check for a __setstate__ method on
240 the result [SF patch 565085]; deepcopy should treat instances of
241 custom metaclasses the same way it treats instances of type 'type'
242 [SF patch 560794].
243
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000244- Sockets now support timeout mode. After s.settimeout(T), where T is
245 a float expressing seconds, subsequent operations raise an exception
246 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000247 mode, use s.settimeout(None). There's also a module function,
248 socket.setdefaulttimeout(T), which sets the default for all sockets
249 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000250
251- getopt.gnu_getopt was added. This supports GNU-style option
252 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000253
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000254- Stop using strings for exceptions. String objects used for
255 exceptions are now classes deriving from Exception. The objects
256 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
257 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000258
Walter Dörwald474458d2002-06-04 15:16:29 +0000259- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
260 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
261 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
262 big endian systems were added to the codecs module. The old names
263 BOM32_* and BOM64_* were off by a factor of 2.
264
Guido van Rossumf9257822002-06-18 20:43:18 +0000265- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000266
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000267- ftplib.retrlines() now tests for callback is None rather than testing
268 for False. Was causing an error when given a callback object which
269 was callable but also returned len() as zero. The change may
270 create new breakage if the caller relied on the undocumented behavior
271 and called with callback set to [] or some other False value not
272 identical to None.
273
Tim Peters46c04e12002-05-05 20:40:00 +0000274- random.gauss() uses a piece of hidden state used by nothing else,
275 and the .seed() and .whseed() methods failed to reset it. In other
276 words, setting the seed didn't completely determine the sequence of
277 results produced by random.gauss(). It does now. Programs repeatedly
278 mixing calls to a seed method with calls to gauss() may see different
279 results now.
280
Fred Drake7f781c92002-05-01 20:33:53 +0000281- The pickle.Pickler class grew a clear_memo() method to mimic that
282 provided by cPickle.Pickler.
283
Tim Peters81b92512002-04-29 01:37:32 +0000284- difflib's SequenceMatcher class now does a dynamic analysis of
285 which elements are so frequent as to constitute noise. For
286 comparing files as sequences of lines, this generally works better
287 than the IS_LINE_JUNK function, and function ndiff's linejunk
288 argument defaults to None now as a result. A happy benefit is
289 that SequenceMatcher may run much faster now when applied
290 to large files with many duplicate lines (for example, C program
291 text with lots of repeated "}" and "return NULL;" lines).
292
Guido van Rossum256705b2002-04-23 13:29:43 +0000293- New Text.dump() method in Tkinter module.
294
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000295- New distutils commands for building packagers were added to
296 support pkgtool on Solaris and swinstall on HP-UX.
297
298- distutils now has a new abstract binary packager base class
299 command/bdist_packager, which simplifies writing packagers.
300 This will hopefully provide the missing bits to encourage
301 people to submit more packagers, e.g. for Debian, FreeBSD
302 and other systems.
303
Guido van Rossumf9257822002-06-18 20:43:18 +0000304- The UTF-16, -LE and -BE stream readers now raise a
305 NotImplementedError for all calls to .readline(). Previously, they
306 used to just produce garbage or fail with an encoding error --
307 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 +0000308 work well with these.
309
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000310- compileall now supports quiet operation.
311
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000312- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000313 connections.
314
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000315- socket module: the SSL support was broken out of the main
316 _socket module C helper and placed into a new _ssl helper
317 which now gets imported by socket.py if available and working.
318
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000319- encodings package: added aliases for all supported IANA character
320 sets
321
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000322- ftplib: to safeguard the user's privacy, anonymous login will use
323 "anonymous@" as default password, rather than the real user and host
324 name.
325
Fred Drake36736122002-01-10 13:50:31 +0000326- webbrowser: tightened up the command passed to os.system() so that
327 arbitrary shell code can't be executed because a bogus URL was
328 passed in.
329
Tim Peters11bd9942002-02-01 00:52:29 +0000330- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000331 gettext.find an optional all argument. Translations will now fallback
332 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000333
Martin v. Löwis9668b932002-01-12 11:27:42 +0000334- distutils bdist commands now offer a --skip-build option.
335
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000336- warnings.warn now accepts a Warning instance as first argument.
337
Fred Drakefed7e852002-04-04 19:36:15 +0000338- The xml.sax.expatreader.ExpatParser class will no longer create
339 circular references by using itself as the locator that gets passed
340 to the content handler implementation. [SF bug #535474]
341
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000342- The email.Parser.Parser class now properly parses strings regardless
343 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
344 or CRLF). Also, the Header class's constructor default arguments
345 has changed slightly so that an explicit maxlinelen value is always
346 honored.
347
Tim Petersaf8446f2001-12-21 21:36:50 +0000348Tools/Demos
349
Fred Drake40813b12002-08-05 15:24:19 +0000350- IDLE supports the new encoding declarations (PEP 263); it can also
351 deal with legacy 8-bit files if they use the locale's encoding. It
352 allows non-ASCII strings in the interactive shell and executes them
353 in the locale's encoding.
Martin v. Löwis98ce7b72002-08-05 15:11:26 +0000354
Marc-André Lemburg46260092002-04-04 16:17:11 +0000355- freeze.py now produces binaries which can import shared modules,
356 unlike before when this failed due to missing symbol exports in
357 the generated binary.
358
Tim Petersaf8446f2001-12-21 21:36:50 +0000359Build
360
Tim Petersf47630f2002-08-01 02:34:51 +0000361- The public Python C API will generally be declared using PyAPI_FUNC
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000362 and PyAPI_DATA macros, while Python extension module init functions
363 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
364 are deprecated.
365
Tim Petersc6a3ff62002-07-08 22:11:52 +0000366- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
367 get into infinite loops, when a new-style class got garbage-collected.
368 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
369 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
370 COUNT_ALLOCS is not enabled by default, in either release or debug
371 builds, and that new-style classes are immortal only in COUNT_ALLOCS
372 builds.
373
Tim Peters943382c2002-07-07 03:59:34 +0000374- Compiling out the cyclic garbage collector is no longer an option.
375 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
376 that it's always defined (for the benefit of any extension modules
377 that may be conditionalizing on it). A bonus is that any extension
378 type participating in cyclic gc can choose to participate in the
379 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
380 to require editing the core to teach the trashcan mechanism about the
381 new type.
382
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000383- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000384
385 The Standard C macro HUGE_VAL and its float and long double analogs,
386 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
387 positive infinities.
388
389 Python only uses the double HUGE_VAL, and only to #define its own symbol
390 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
391 pyport.h used to try to worm around that, but the workarounds triggered
392 other bugs on other platforms, so we gave up. If your platform defines
393 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
394 that works on your platform. The only instance of this I'm sure about
395 is on an unknown subset of Cray systems, described here:
396
397 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
398
399 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
400
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000401- The configure option --without-doc-strings can be used to remove the
402 doc strings from the builtin functions and modules; this reduces the
403 size of the executable.
404
Tim Peters639295f2002-04-21 07:30:30 +0000405- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
406 say how or when to configure it, or how to turn it off.
407
Martin v. Löwis1142de32002-03-29 16:28:31 +0000408- On Unix, a shared libpython2.3.so can be created with --enable-shared.
409
Tim Peters8deda702002-03-30 10:06:07 +0000410- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
411 preprocessor symbols were eliminated. The internal decisions they
412 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000413
Fred Drake7d28b732002-05-02 21:17:00 +0000414- The tools used to build the documentation now work under Cygwin as
415 well as Unix.
416
Skip Montanaro57454e52002-06-14 20:30:31 +0000417- The bsddb and dbm module builds have been changed to try and avoid version
418 skew problems and disable linkage with Berkeley DB 1.85 unless the
419 installer knows what s/he's doing. See the section on building these
420 modules in the README file for details.
421
Tim Petersaf8446f2001-12-21 21:36:50 +0000422C API
423
Thomas Heller085358a2002-07-29 14:27:41 +0000424- New functions PyErr_SetExcFromWindowsErr() and
425 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
426 PyErr_SetFromWindowsErrWithFilename() and
427 PyErr_SetFromWindowsErr(), but they allow to specify
428 the exception type to raise. Available on Windows.
429
Tim Peters7c321a82002-07-09 02:57:01 +0000430- Py_FatalError() is now declared as taking a const char* argument. It
431 was previously declared without const. This should not affect working
432 code.
433
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000434- Added new macro PySequence_ITEM(o, i) that directly calls
435 sq_item without rechecking that o is a sequence and without
436 adjusting for negative indices.
437
Fred Draked0ba6362002-05-02 21:28:26 +0000438- PyRange_New() now raises ValueError if the fourth argument is not 1.
439 This is part of the removal of deprecated features of the xrange
440 object.
441
Guido van Rossum517c7d42002-04-26 02:49:14 +0000442- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
443 coercion if both arguments have the same type but this type has the
444 CHECKTYPES flag set. This is to better support proxies.
445
Neil Schemenauer9344b142002-04-12 23:00:08 +0000446- The type of tp_free has been changed from "void (*)(PyObject *)" to
447 "void (*)(void *)".
448
449- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
450
Guido van Rossum0986d822002-04-08 01:38:42 +0000451- A type can now inherit its metatype from its base type. Previously,
452 when PyType_Ready() was called, if ob_type was found to be NULL, it
453 was always set to &PyType_Type; now it is set to base->ob_type,
454 where base is tp_base, defaulting to &PyObject_Type.
455
456- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
457
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000458- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000459
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000460- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000461 without going through the buffer API.
462
Martin v. Löwis7198a522002-01-01 19:59:11 +0000463- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
464
Tim Peters10a3bb52001-12-25 19:07:38 +0000465- An old #define of ANY as void has been removed from pyport.h. This
466 hasn't been used since Python's pre-ANSI days, and the #define has
467 been marked as obsolete since then. SF bug 495548 says it created
468 conflicts with other packages, so keeping it around wasn't harmless.
469
Tim Petersaf8446f2001-12-21 21:36:50 +0000470- Because Python's magic number scheme broke on January 1st, we decided
471 to stop Python development. Thanks for all the fish!
472
Tim Petersfb05db22002-03-11 00:24:00 +0000473- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000474 scheme to a new one. See Python/import.c for details.
475
Tim Petersaf8446f2001-12-21 21:36:50 +0000476New platforms
477
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000478- AtheOS is now supported.
479
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000480- the EMX runtime environment on OS/2 is now supported.
481
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000482- GNU/Hurd is now supported.
483
Tim Petersaf8446f2001-12-21 21:36:50 +0000484Tests
485
486Windows
487
Tim Peters08e72952002-04-16 20:48:01 +0000488- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
489 of that has been fixed in the installer (disabled Wise's "delete in-
490 use files" uninstall option).
491
Guido van Rossum181e41a2002-04-06 00:23:25 +0000492- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
493
Tim Peters33187922002-04-04 20:02:04 +0000494- The installer now installs Start menu shortcuts under (the local
495 equivalent of) "All Users" when doing an Admin install.
496
Tim Petersfb05db22002-03-11 00:24:00 +0000497- file.truncate([newsize]) now works on Windows for all newsize values.
498 It used to fail if newsize didn't fit in 32 bits, reflecting a
499 limitation of MS _chsize (which is no longer used).
500
Tim Petersab034fa2002-02-01 11:27:43 +0000501- os.waitpid() is now implemented for Windows, and can be used to block
502 until a specified process exits. This is similar to, but not exactly
503 the same as, os.waitpid() on POSIX systems. If you're waiting for
504 a specific process whose pid was obtained from one of the spawn()
505 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000506 See the docs for details. The docs were changed to clarify that
507 spawn functions return, and waitpid requires, a process handle on
508 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000509
Tim Peters11bd9942002-02-01 00:52:29 +0000510- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000511 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000512 to a nasty problem: before 2.3, if you got a temp file on Windows, it
513 got wrapped in an object whose close() method first closed the
514 underlying file, then deleted the file. This usually worked fine.
515 However, the spawn family of functions on Windows create (at a low C
516 level) the same set of open files in the spawned process Q as were
517 open in the spawning process P. If a temp file f was among them, then
518 doing f.close() in P first closed P's C-level file handle on f, but Q's
519 C-level file handle on f remained open, so the attempt in P to delete f
520 blew up with a "Permission denied" error (Windows doesn't allow
521 deleting open files). This was surprising, subtle, and difficult to
522 work around.
523
524- The os module now exports all the symbolic constants usable with the
525 low-level os.open() on Windows: the new constants in 2.3 are
526 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
527 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
528 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
529 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
530 (so specify both if you want both; note that neither is useful unless
531 specified with O_CREAT too).
532
Tim Petersaf8446f2001-12-21 21:36:50 +0000533Mac
534
535
Tim Peters909c0912001-12-14 23:16:18 +0000536What's New in Python 2.2 final?
537Release date: 21-Dec-2001
538===============================
539
540Type/class unification and new-style classes
541
Barry Warsaw52acb492001-12-21 20:04:22 +0000542- pickle.py, cPickle: allow pickling instances of new-style classes
543 with a custom metaclass.
544
Tim Peters909c0912001-12-14 23:16:18 +0000545Core and builtins
546
Barry Warsaw52acb492001-12-21 20:04:22 +0000547- weakref proxy object: when comparing, unwrap both arguments if both
548 are proxies.
549
Tim Peters909c0912001-12-14 23:16:18 +0000550Extension modules
551
Barry Warsaw52acb492001-12-21 20:04:22 +0000552- binascii.b2a_base64(): fix a potential buffer overrun when encoding
553 very short strings.
554
555- cPickle: the obscure "fast" mode was suspected of causing stack
556 overflows on the Mac. Hopefully fixed this by setting the recursion
557 limit much smaller. If the limit is too low (it only affects
558 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
559 when compiling cPickle.c (or in pyconfig.h).
560
Tim Peters909c0912001-12-14 23:16:18 +0000561Library
562
Barry Warsaw52acb492001-12-21 20:04:22 +0000563- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
564 close or delete time).
565
566- rfc822.py: fixed a bug where the address '<>' was converted to None
567 instead of an empty string (also fixes the email.Utils module).
568
569- xmlrpclib.py: version 1.0.0; uses precision for doubles.
570
571- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000572 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000573
Tim Peters909c0912001-12-14 23:16:18 +0000574Tools/Demos
575
576Build
577
578C API
579
580New platforms
581
582Tests
583
584Windows
585
Barry Warsaw52acb492001-12-21 20:04:22 +0000586- distutils package: fixed broken Windows installers (bdist_wininst).
587
588- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
589 instances are deleted at process exit time.
590
591- socket.py: prevent mysterious warnings when socket instances are
592 deleted at process exit time.
593
594- posixmodule.c: fix a Windows crash with stat() of a filename ending
595 in backslash.
596
Tim Peters909c0912001-12-14 23:16:18 +0000597Mac
598
Barry Warsaw52acb492001-12-21 20:04:22 +0000599- The Carbon toolbox modules have been upgraded to Universal Headers
600 3.4, and experimental CoreGraphics and CarbonEvents modules have
601 been added. All only for framework-enabled MacOSX.
602
Tim Peters909c0912001-12-14 23:16:18 +0000603
Tim Peters6272dfd2001-12-13 19:34:00 +0000604What's New in Python 2.2c1?
605Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000606===========================
607
608Type/class unification and new-style classes
609
Barry Warsaw06557452001-12-14 20:47:12 +0000610- Guido's tutorial introduction to the new type/class features has
611 been extensively updated. See
612
613 http://www.python.org/2.2/descrintro.html
614
615 That remains the primary documentation in this area.
616
Guido van Rossum33bab012001-12-05 22:45:48 +0000617- Fixed a leak: instance variables declared with __slots__ were never
618 deleted!
619
Guido van Rossum4b800852001-12-03 00:54:52 +0000620- The "delete attribute" method of descriptor objects is called
621 __delete__, not __del__. In previous releases, it was mistakenly
622 called __del__, which created an unfortunate overloading condition
623 with finalizers. (The "get attribute" and "set attribute" methods
624 are still called __get__ and __set__, respectively.)
625
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000626- Some subtle issues with the super built-in were fixed:
627
628 (a) When super itself is subclassed, its __get__ method would still
629 return an instance of the base class (i.e., of super).
630
631 (b) super(C, C()).__class__ would return C rather than super. This
632 is confusing. To fix this, I decided to change the semantics of
633 super so that it only applies to code attributes, not to data
634 attributes. After all, overriding data attributes is not
635 supported anyway.
636
637 (c) The __get__ method didn't check whether the argument was an
638 instance of the type used in creation of the super instance.
639
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000640- Previously, hash() of an instance of a subclass of a mutable type
641 (list or dictionary) would return some value, rather than raising
642 TypeError. This has been fixed. Also, directly calling
643 dict.__hash__ and list.__hash__ now raises the same TypeError
644 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000645
Guido van Rossumd331cb52001-12-05 19:46:42 +0000646- New-style objects now support deleting their __dict__. This is for
647 all intents and purposes equivalent to assigning a brand new empty
648 dictionary, but saves space if the object is not used further.
649
Tim Petersb3c9af12001-11-17 00:21:57 +0000650Core and builtins
651
Tim Peters3caca232001-12-06 06:23:26 +0000652- -Qnew now works as documented in PEP 238: when -Qnew is passed on
653 the command line, all occurrences of "/" use true division instead
654 of classic division. See the PEP for details. Note that "all"
655 means all instances in library and 3rd-party modules, as well as in
656 your own code. As the PEP says, -Qnew is intended for use only in
657 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000658 Note that test_coercion.py in the standard Python test suite fails
659 under -Qnew; this is expected, and won't be repaired until true
660 division becomes the default (in the meantime, test_coercion is
661 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000662
Fred Drake6c01e252001-12-14 17:08:12 +0000663- complex() now only allows the first argument to be a string
664 argument, and raises TypeError if either the second arg is a string
665 or if the second arg is specified when the first is a string.
666
Tim Petersb3c9af12001-11-17 00:21:57 +0000667Extension modules
668
Martin v. Löwis560da622001-11-24 09:24:51 +0000669- gc.get_referents was renamed to gc.get_referrers.
670
Tim Petersb3c9af12001-11-17 00:21:57 +0000671Library
672
Tim Peters25059d32001-12-07 20:35:43 +0000673- Functions in the os.spawn() family now release the global interpreter
674 lock around calling the platform spawn. They should always have done
675 this, but did not before 2.2c1. Multithreaded programs calling
676 an os.spawn function with P_WAIT will no longer block all Python threads
677 until the spawned program completes. It's possible that some programs
678 relies on blocking, although more likely by accident than by design.
679
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000680- webbrowser defaults to netscape.exe on OS/2 now.
681
Martin v. Löwis652e1912001-11-25 14:50:56 +0000682- Tix.ResizeHandle exposes detach_widget, hide, and show.
683
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000684- The charset alias windows_1252 has been added.
685
Barry Warsaw06557452001-12-14 20:47:12 +0000686- types.StringTypes is a tuple containing the defined string types;
687 usually this will be (str, unicode), but if Python was compiled
688 without Unicode support it will be just (str,).
689
690- The pulldom and minidom modules were synchronized to PyXML.
691
Tim Petersb3c9af12001-11-17 00:21:57 +0000692Tools/Demos
693
Barry Warsaw06557452001-12-14 20:47:12 +0000694- A new script called Tools/scripts/google.py was added, which fires
695 off a search on Google.
696
Tim Petersb3c9af12001-11-17 00:21:57 +0000697Build
698
Barry Warsaw06557452001-12-14 20:47:12 +0000699- Note that release builds of Python should arrange to define the
700 preprocessor symbol NDEBUG on the command line (or equivalent).
701 In the 2.2 pre-release series we tried to define this by magic in
702 Python.h instead, but it proved to cause problems for extension
703 authors. The Unix, Windows and Mac builds now all define NDEBUG in
704 release builds via cmdline (or equivalent) instead. Ports to
705 other platforms should do likewise.
706
Jack Jansen1999ef42001-12-06 21:47:20 +0000707- It is no longer necessary to use --with-suffix when building on a
708 case-insensitive file system (such as Mac OS X HFS+). In the build
709 directory an extension is used, but not in the installed python.
710
Tim Petersb3c9af12001-11-17 00:21:57 +0000711C API
712
Tim Petersf582b822001-12-11 18:51:08 +0000713- New function PyDict_MergeFromSeq2() exposes the builtin dict
714 constructor's logic for updating a dictionary from an iterable object
715 producing key-value pairs.
716
Tim Peterscffed4b2001-11-29 03:26:37 +0000717- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000718 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000719 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
720 dump core in some bad cases. This has been repaired. As a result,
721 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
722 previously went unchallenged.
723
Tim Petersb3c9af12001-11-17 00:21:57 +0000724New platforms
725
726Tests
727
728Windows
729
730Mac
731
Jack Jansenffa260f2001-12-06 21:14:00 +0000732- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
733 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000734
Barry Warsaw06557452001-12-14 20:47:12 +0000735- Changed logic for finding python home in Mac OS X framework Pythons.
736 Now sys.executable points to the executable again, in stead of to
737 the shared library. The latter is used only for locating the python
738 home.
739
740
Tim Peters84362bc2001-10-19 17:55:30 +0000741What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000742Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000743===========================
744
745Type/class unification and new-style classes
746
Guido van Rossum3d27df02001-11-15 20:27:54 +0000747- Multiple inheritance mixing new-style and classic classes in the
748 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000749
750 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000751 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000752
753 The MRO (method resolution order) for each base class is respected
754 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000755 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000756 This needs to be documented.
757
Tim Petersa427a2b2001-10-29 22:25:45 +0000758- The new builtin dictionary() constructor, and dictionary type, have
759 been renamed to dict. This reflects a decade of common usage.
760
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000761- dict() now accepts an iterable object producing 2-sequences. For
762 example, dict(d.items()) == d for any dictionary d. The argument,
763 and the elements of the argument, can be any iterable objects.
764
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000765- New-style classes can now have a __del__ method, which is called
766 when the instance is deleted (just like for classic classes).
767
Guido van Rossum12d955c2001-10-26 14:56:06 +0000768- Assignment to object.__dict__ is now possible, for objects that are
769 instances of new-style classes that have a __dict__ (unless the base
770 class forbids it).
771
Guido van Rossumc8e56452001-10-22 00:43:43 +0000772- Methods of built-in types now properly check for keyword arguments
773 (formerly these were silently ignored). The only built-in methods
774 that take keyword arguments are __call__, __init__ and __new__.
775
Guido van Rossum86443212001-10-27 22:28:54 +0000776- The socket function has been converted to a type; see below.
777
Tim Peters84362bc2001-10-19 17:55:30 +0000778Core and builtins
779
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000780- Assignment to __debug__ raises SyntaxError at compile-time. This
781 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000782 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000783
Guido van Rossum12d955c2001-10-26 14:56:06 +0000784- Clarified the error messages for unsupported operands to an operator
785 (like 1 + '').
786
Tim Peters84362bc2001-10-19 17:55:30 +0000787Extension modules
788
Tim Peters5ebfd362001-11-13 23:11:19 +0000789- mmap has a new keyword argument, "access", allowing a uniform way for
790 both Windows and Unix users to create read-only, write-through and
791 copy-on-write memory mappings. This was previously possible only on
792 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000793 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000794 platforms. Thanks to Jay T Miller for repairing this!
795
Tim Peters169ded02001-11-03 19:57:21 +0000796- By default, the gc.garbage list now contains only those instances in
797 unreachable cycles that have __del__ methods; in 2.1 it contained all
798 instances in unreachable cycles. "Instances" here has been generalized
799 to include instances of both new-style and old-style classes.
800
Guido van Rossum12d955c2001-10-26 14:56:06 +0000801- The socket module defines a new method for socket objects,
802 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000803 send() until all data has been sent. Also, the socket function has
804 been converted to a subclassable type, like list and tuple (etc.)
805 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000806
807- Various bugfixes to the curses module. There is now a test suite
808 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000809
Guido van Rossum692adf12001-10-30 03:03:03 +0000810- binascii.b2a_base64 no longer places an arbitrary restriction of 57
811 bytes on its input.
812
Tim Peters84362bc2001-10-19 17:55:30 +0000813Library
814
Tim Peters5ebfd362001-11-13 23:11:19 +0000815- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000816 convenience function.
817
Tim Peters75335872001-11-03 19:35:43 +0000818- Symbolic group names in regular expressions must be unique. For
819 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
820 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000821 Python 2.2 detects this error at regexp compilation time;
822 previously, the error went undetected, and results were
823 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
824 pattern.subn() methods have been rewritten in C. Also, an
825 experimental function/method finditer() has been added, which works
826 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000827
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000828- Tix exposes more commands through the classes DirSelectBox,
829 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
830 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
831 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
832
Tim Peters98791af2001-10-23 01:59:54 +0000833- Traceback objects are now scanned by cyclic garbage collection, so
834 cycles created by casual use of sys.exc_info() no longer cause
835 permanent memory leaks (provided garbage collection is enabled).
836
Guido van Rossum49192142001-10-24 20:51:44 +0000837- os.extsep -- a new variable needed by the RISCOS support. It is the
838 separator used by extensions, and is '.' on all platforms except
839 RISCOS, where it is '/'. There is no need to use this variable
840 unless you have a masochistic desire to port your code to RISCOS.
841
Barry Warsaw012852b2001-11-16 16:17:27 +0000842- mimetypes.py has optional support for non-standard, but commonly
843 found types. guess_type() and guess_extension() now accept an
844 optional `strict' flag, defaulting to true, which controls whether
845 recognize non-standard types or not. A few non-standard types we
846 know about have been added. Also, when run as a script, there are
847 new -l and -e options.
848
849- statcache is now deprecated.
850
851- email.Utils.formatdate() now produces the preferred RFC 2822 style
852 dates with numeric timezones (it used to produce obsolete dates
853 hard coded to "GMT" timezone). An optional `localtime' flag is
854 added to produce dates in the local timezone, with daylight savings
855 time properly taken into account.
856
857- In pickle and cPickle, instead of masking errors in load() by
858 transforming them into SystemError, we let the original exception
859 propagate out. Also, implement support for __safe_for_unpickling__
860 in pickle, as it already was supported in cPickle.
861
Tim Peters84362bc2001-10-19 17:55:30 +0000862Tools/Demos
863
864Build
865
Barry Warsaw012852b2001-11-16 16:17:27 +0000866- The dbm module is built using libdb1 if available. The bsddb module
867 is built with libdb3 if available.
868
869- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
870
Tim Peters84362bc2001-10-19 17:55:30 +0000871C API
872
Tim Peters1fc240e2001-10-26 05:06:50 +0000873- New function PySequence_Fast_GET_SIZE() returns the size of a non-
874 NULL result from PySequence_Fast(), more quickly than calling
875 PySequence_Size().
876
Barry Warsaw012852b2001-11-16 16:17:27 +0000877- New argument unpacking function PyArg_UnpackTuple() added.
878
879- New functions PyObject_CallFunctionObjArgs() and
880 PyObject_CallMethodObjArgs() have been added to make it more
881 convenient and efficient to call functions and methods from C.
882
883- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
884 possible that this will propagate errors it didn't before.
885
886- New function PyObject_CheckReadBuffer(), which returns true if its
887 argument supports the single-segment readable buffer interface.
888
Tim Peters84362bc2001-10-19 17:55:30 +0000889New platforms
890
Guido van Rossum86443212001-10-27 22:28:54 +0000891- We've finally confirmed that this release builds on HP-UX 11.00,
892 *with* threads, and passes the test suite.
893
Tim Peters7a33d8b2001-11-05 02:51:07 +0000894- Thanks to a series of patches from Michael Muller, Python may build
895 again under OS/2 Visual Age C++.
896
Guido van Rossum49192142001-10-24 20:51:44 +0000897- Updated RISCOS port by Dietmar Schwertberger.
898
Tim Peters84362bc2001-10-19 17:55:30 +0000899Tests
900
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000901- Added a test script for the curses module. It isn't run automatically;
902 regrtest.py must be run with '-u curses' to enable it.
903
Tim Peters84362bc2001-10-19 17:55:30 +0000904Windows
905
Barry Warsaw012852b2001-11-16 16:17:27 +0000906Mac
907
908- PythonScript has been moved to unsupported and is slated to be
909 removed completely in the next release.
910
911- It should now be possible to build applets that work on both OS9 and
912 OSX.
913
914- The core is now linked with CoreServices not Carbon; as a side
915 result, default 8bit encoding on OSX is now ASCII.
916
917- Python should now build on OSX 10.1.1
918
Tim Peters84362bc2001-10-19 17:55:30 +0000919
Tim Petersabf925f2001-09-28 21:53:42 +0000920What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000921Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000922===========================
923
924Type/class unification and new-style classes
925
Guido van Rossum687ae002001-10-15 22:03:32 +0000926- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000927 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000928 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000929 remains: the __dict__ of a new-style class is a read-only proxy; you
930 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000931 __defined__ attribute of new-style types no longer exists, for lack
932 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000933 future a __cache__ may be resurrected with a similar function, if I
934 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000935
Tim Peters1c9ca872001-10-04 06:43:12 +0000936- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
937 always returned None, even when there was a class docstring).
938
939- doctest now finds and runs docstrings attached to new-style classes,
940 class methods, static methods, and properties.
941
Guido van Rossum9074ef62001-10-16 21:34:49 +0000942Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000943
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000944- A very subtle syntactical pitfall in list comprehensions was fixed.
945 For example: [a+b for a in 'abc', for b in 'def']. The comma in
946 this example is a mistake. Previously, this would silently let 'a'
947 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
948 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
949 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
950 Note that [a for a in <singleton>] is a convoluted way to say
951 [<singleton>] anyway, so it's not like any expressiveness is lost.
952
Guido van Rossum9074ef62001-10-16 21:34:49 +0000953- getattr(obj, name, default) now only catches AttributeError, as
954 documented, rather than returning the default value for all
955 exceptions (which could mask bugs in a __getattr__ hook, for
956 example).
957
Fred Drakecb7a6b52001-10-22 18:41:51 +0000958- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000959 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000960 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000961 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000962
Guido van Rossum1c486092001-10-19 02:05:35 +0000963- unicode(obj) now behaves more like str(obj), accepting arbitrary
964 objects, and calling a __unicode__ method if it exists.
965 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000966 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000967
Barry Warsawf6fb1712001-10-19 05:35:40 +0000968- isinstance() now allows any object as the first argument and a
969 class, a type or something with a __bases__ tuple attribute for the
970 second argument. The second argument may also be a tuple of a
971 class, type, or something with __bases__, in which case isinstance()
972 will return true if the first argument is an instance of any of the
973 things contained in the second argument tuple. E.g.
974
975 isinstance(x, (A, B))
976
977 returns true if x is an instance of A or B.
978
Guido van Rossum9074ef62001-10-16 21:34:49 +0000979Extension modules
980
981- thread.start_new_thread() now returns the thread ID (previously None).
982
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000983- binascii has now two quopri support functions, a2b_qp and b2a_qp.
984
Guido van Rossumc524d952001-10-19 01:31:59 +0000985- readline now supports setting the startup_hook and the
986 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000987
Guido van Rossumc524d952001-10-19 01:31:59 +0000988- os and posix supports chroot(), setgroups() and unsetenv() where
989 available. The stat(), fstat(), statvfs() and fstatvfs() functions
990 now return "pseudo-sequences" -- the various fields can now be
991 accessed as attributes (e.g. os.stat("/").st_mtime) but for
992 backwards compatibility they also behave as a fixed-length sequence.
993 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000994 attributes.
995
996- time: localtime(), gmtime() and strptime() now return a
997 pseudo-sequence similar to the os.stat() return value, with
998 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000999
Guido van Rossum9074ef62001-10-16 21:34:49 +00001000- Decompression objects in the zlib module now accept an optional
1001 second parameter to decompress() that specifies the maximum amount
1002 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +00001003
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001004- optional SSL support in the socket module now exports OpenSSL
1005 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
1006 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +00001007 automatically seed its PRNG. Also, the keyfile and certfile
1008 arguments to socket.ssl() are now optional.
1009
1010- posixmodule (and by extension, the os module on POSIX platforms) now
1011 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001012
Guido van Rossum9074ef62001-10-16 21:34:49 +00001013Library
Guido van Rossum3c288632001-10-16 21:13:49 +00001014
Tim Peters7402f792001-10-02 03:53:41 +00001015- doctest now excludes functions and classes not defined by the module
1016 being tested, thanks to Tim Hochberg.
1017
Fred Drakecb7a6b52001-10-22 18:41:51 +00001018- HotShot, a new profiler implemented using a C-based callback, has
1019 been added. This substantially reduces the overhead of profiling,
1020 but it is still quite preliminary. Support modules and
1021 documentation will be added in upcoming releases (before 2.2 final).
1022
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001023- profile now produces correct output in situations where an exception
1024 raised in Python is cleared by C code (e.g. hasattr()). This used
1025 to cause wrong output, including spurious claims of recursive
1026 functions and attribution of time spent to the wrong function.
1027
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001028 The code and documentation for the derived OldProfile and HotProfile
1029 profiling classes was removed. The code hasn't worked for years (if
1030 you tried to use them, they raised exceptions). OldProfile
1031 intended to reproduce the behavior of the profiler Python used more
1032 than 7 years ago, and isn't interesting anymore. HotProfile intended
1033 to provide a faster profiler (but producing less information), and
1034 that's a worthy goal we intend to meet via a different approach (but
1035 without losing information).
1036
Tim Peterscce092d2001-10-09 05:31:56 +00001037- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001038 a much better system-specific calibration constant. The constant can
1039 now be specified in an instance constructor, or as a Profile class or
1040 instance variable, instead of by editing profile.py's source code.
1041 Calibration must still be done manually (see the docs for the profile
1042 module).
1043
1044 Note that Profile.calibrate() must be overriden by subclasses.
1045 Improving the accuracy required exploiting detailed knowledge of
1046 profiler internals; the earlier method abstracted away the details
1047 and measured a simplified model instead, but consequently computed
1048 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001049
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001050- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001051 which indicates whether output is intended for the header 'Q'
1052 encoding.
1053
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001054- The SocketServer.ThreadingMixIn class now closes the request after
1055 finish_request() returns. (Not when it errors out though.)
1056
Barry Warsawf6fb1712001-10-19 05:35:40 +00001057- The nntplib module's NNTP.body() method has grown a `file' argument
1058 to allow saving the message body to a file.
1059
1060- The email package has added a class email.Parser.HeaderParser which
1061 only parses headers and does not recurse into the message's body.
1062 Also, the module/class MIMEAudio has been added for representing
1063 audio data (contributed by Anthony Baxter).
1064
1065- ftplib should be able to handle files > 2GB.
1066
1067- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1068 ON, and OFF.
1069
Fred Drakecb7a6b52001-10-22 18:41:51 +00001070- xml.dom.minidom NodeList objects now support the length attribute
1071 and item() method as required by the DOM specifications.
1072
Guido van Rossumed554f62001-10-02 23:15:37 +00001073Tools/Demos
1074
1075- Demo/dns was removed. It no longer serves any purpose; a package
1076 derived from it is now maintained by Anthony Baxter, see
1077 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001078
Barry Warsawf6fb1712001-10-19 05:35:40 +00001079- The freeze tool has been made more robust, and two new options have
1080 been added: -X and -E.
1081
Tim Petersabf925f2001-09-28 21:53:42 +00001082Build
1083
Barry Warsawf6fb1712001-10-19 05:35:40 +00001084- configure will use CXX in LINKCC if CXX is used to build main() and
1085 the system requires to link a C++ main using the C++ compiler.
1086
Tim Petersabf925f2001-09-28 21:53:42 +00001087C API
1088
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001089- The documentation for the tp_compare slot is updated to require that
1090 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1091 not correct. This is not yet enforced but will be enforced in
1092 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1093 "NotImplemented". Right now, -1 should be used for an error return.
1094
Tim Petersd38b1c72001-09-30 05:09:37 +00001095- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1096 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1097 as long) arguments.
1098
Guido van Rossum3c288632001-10-16 21:13:49 +00001099- PyThread_start_new_thread() now returns a long int giving the thread
1100 ID, if one can be calculated; it returns -1 for error, 0 if no
1101 thread ID is calculated (this is an incompatible change, but only
1102 the thread module used this API). This code has only really been
1103 tested on Linux and Windows; other platforms please beware (and
1104 report any bugs or strange behavior).
1105
Guido van Rossum1c486092001-10-19 02:05:35 +00001106- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1107 input.
1108
Tim Petersabf925f2001-09-28 21:53:42 +00001109New platforms
1110
1111Tests
1112
1113Windows
1114
Tim Peters04cf1d32001-10-09 22:39:40 +00001115- Installer: If you install IDLE, and don't disable file-extension
1116 registration, a new "Edit with IDLE" context (right-click) menu entry
1117 is created for .py and .pyw files.
1118
Tim Peters1ce3cf72001-10-01 17:58:40 +00001119- The signal module now supports SIGBREAK on Windows, thanks to Steven
1120 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1121 action remains to call Win32 ExitProcess(). This can be changed via
1122 signal.signal(). For example:
1123
1124 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1125 # (SIGINT) behavior.
1126 import signal
1127 signal.signal(signal.SIGBREAK,
1128 signal.default_int_handler)
1129
1130 try:
1131 while 1:
1132 pass
1133 except KeyboardInterrupt:
1134 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1135 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1136 # program without the possibility for any Python-level cleanup).
1137 print "Clean exit"
1138
Tim Petersabf925f2001-09-28 21:53:42 +00001139
Tim Petersb07352e2001-09-08 01:25:47 +00001140What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001141Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001142===========================
1143
Guido van Rossum808eea72001-09-25 04:15:41 +00001144Type/class unification and new-style classes
1145
1146- pydoc and inspect are now aware of new-style classes;
1147 e.g. help(list) at the interactive prompt now shows proper
1148 documentation for all operations on list objects.
1149
1150- Applications using Jim Fulton's ExtensionClass module can now safely
1151 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1152 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1153 examples also work again. It is hoped that Gtk and Boost also work
1154 with 2.2a4 and beyond. (If you can confirm this, please write
1155 webmaster@python.org; if there are still problems, please open a bug
1156 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001157
Tim Peters66c1a522001-09-24 21:17:50 +00001158- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001159 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001160 in the constructed property object. fget, fset and fdel weren't
1161 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1162 associate a docstring with a property.
1163
Guido van Rossum808eea72001-09-25 04:15:41 +00001164- Comparison overloading is now more completely implemented. For
1165 example, a str subclass instance can properly be compared to a str
1166 instance, and it can properly overload comparison. Ditto for most
1167 other built-in object types.
1168
1169- The repr() of new-style classes has changed; instead of <type
1170 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1171 *except* for built-in types, which are still rendered as <type
1172 'Foo'> (to avoid upsetting existing code that might parse or
1173 otherwise rely on repr() of certain type objects).
1174
1175- The repr() of new-style objects is now always <Foo object at XXX>;
1176 previously, it was sometimes <Foo instance at XXX>.
1177
1178- For new-style classes, what was previously called __getattr__ is now
1179 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001180 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001181 one in classic classes is defined which is called only if regular
1182 attribute access raises AttributeError; to catch *all* attribute
1183 access, you can use __getattribute__ (for new-style classes). If
1184 both are defined, __getattribute__ is called first, and if it raises
1185 AttributeError, __getattr__ is called.
1186
1187- The __class__ attribute of new-style objects can be assigned to.
1188 The new class must have the same C-level object layout as the old
1189 class.
1190
1191- The builtin file type can be subclassed now. In the usual pattern,
1192 "file" is the name of the builtin type, and file() is a new builtin
1193 constructor, with the same signature as the builtin open() function.
1194 file() is now the preferred way to open a file.
1195
1196- Previously, __new__ would only see sequential arguments passed to
1197 the type in a constructor call; __init__ would see both sequential
1198 and keyword arguments. This made no sense whatsoever any more, so
1199 now both __new__ and __init__ see all arguments.
1200
1201- Previously, hash() applied to an instance of a subclass of str or
1202 unicode always returned 0. This has been repaired.
1203
1204- Previously, an operation on an instance of a subclass of an
1205 immutable type (int, long, float, complex, tuple, str, unicode),
1206 where the subtype didn't override the operation (and so the
1207 operation was handled by the builtin type), could return that
1208 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001209 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001210 with the same value as s.
1211
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001212- Provisional support for pickling new-style objects has been added.
1213
Guido van Rossum808eea72001-09-25 04:15:41 +00001214Core
1215
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001216- file.writelines() now accepts any iterable object producing strings.
1217
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001218- PyUnicode_FromEncodedObject() now works very much like
1219 PyObject_Str(obj) in that it tries to use __str__/tp_str
1220 on the object if the object is not a string or buffer. This
1221 makes unicode() behave like str() when applied to non-string/buffer
1222 objects.
1223
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001224- PyFile_WriteObject now passes Unicode objects to the file's write
1225 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001226 of a print statement must support Unicode objects, i.e. they must
1227 at least convert them into ASCII strings.
1228
Guido van Rossum624c8af2001-09-18 15:21:04 +00001229- Thread scheduling on Solaris should be improved; it is no longer
1230 necessary to insert a small sleep at the start of a thread in order
1231 to let other runnable threads be scheduled.
1232
Tim Petersb07352e2001-09-08 01:25:47 +00001233Library
1234
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001235- StringIO.StringIO instances and cStringIO.StringIO instances support
1236 read character buffer compatible objects for their .write() methods.
1237 These objects are converted to strings and then handled as such
1238 by the instances.
1239
Barry Warsaw2f600732001-09-24 04:28:10 +00001240- The "email" package has been added. This is basically a port of the
1241 mimelib package <http://sf.net/projects/mimelib> with API changes
1242 and some implementations updated to use iterators and generators.
1243
Tim Peters8a9c2842001-09-22 21:30:22 +00001244- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1245 restores the ability of Tools/scripts/ndiff.py to start producing output
1246 before the entire comparison is complete.
1247
Barry Warsaw58b072d2001-09-22 04:44:21 +00001248- StringIO.StringIO instances and cStringIO.StringIO instances support
1249 iteration just like file objects (i.e. their .readline() method is
1250 called for each iteration until it returns an empty string).
1251
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001252- The codecs module has grown four new helper APIs to access
1253 builtin codecs: getencoder(), getdecoder(), getreader(),
1254 getwriter().
1255
Guido van Rossum624c8af2001-09-18 15:21:04 +00001256- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1257 simplifies writing XML RPC servers.
1258
Barry Warsaw647d5e82001-09-28 17:01:02 +00001259- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001260 after interpretation of symbolic links. On non-Unix systems, this
1261 is an alias for os.path.abspath().
1262
Tim Peters16a77ad2001-09-08 04:00:12 +00001263- operator.indexOf() (PySequence_Index() in the C API) now works with any
1264 iterable object.
1265
Guido van Rossum624c8af2001-09-18 15:21:04 +00001266- smtplib now supports various authentication and security features of
1267 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001268
Guido van Rossum624c8af2001-09-18 15:21:04 +00001269- hmac: a new module implementing keyed hashing for message
1270 authentication.
1271
1272- mimetypes now recognizes more extensions and file types. At the
1273 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001274
Guido van Rossum624c8af2001-09-18 15:21:04 +00001275- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001276 Python 2.2 bytecode generation. It has also been promoted from a
1277 Tool to a standard library package. (Tools/compiler still exists as
1278 a sample driver.)
1279
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001280Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001281
Tim Petersb07352e2001-09-08 01:25:47 +00001282Build
1283
Guido van Rossum624c8af2001-09-18 15:21:04 +00001284- Large file support (LFS) is now automatic when the platform supports
1285 it; no more manual configuration tweaks are needed. On Linux, at
1286 least, it's possible to have a system whose C library supports large
1287 files but whose kernel doesn't; in this case, large file support is
1288 still enabled but doesn't do you any good unless you upgrade your
1289 kernel or share your Python executable with another system whose
1290 kernel has large file support.
1291
1292- The configure script now supplies plausible defaults in a
1293 cross-compilation environment. This doesn't mean that the supplied
1294 values are always correct, or that cross-compilation now works
1295 flawlessly -- but it's a first step (and it shuts up most of
1296 autoconf's warnings about AC_TRY_RUN).
1297
1298- The Unix build is now a bit less chatty, courtesy of the parser
1299 generator. The build is completely silent (except for errors) when
1300 using "make -s", thanks to a -q option to setup.py.
1301
Tim Petersb07352e2001-09-08 01:25:47 +00001302C API
1303
Guido van Rossum624c8af2001-09-18 15:21:04 +00001304- The "structmember" API now supports some new flag bits to deny read
1305 and/or write access to attributes in restricted execution mode.
1306
Tim Petersb07352e2001-09-08 01:25:47 +00001307New platforms
1308
Guido van Rossum624c8af2001-09-18 15:21:04 +00001309- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1310 (http://familiar.handhelds.org).
1311
Tim Petersb07352e2001-09-08 01:25:47 +00001312Tests
1313
Tim Peters8a9c2842001-09-22 21:30:22 +00001314- The "classic" standard tests, which work by comparing stdout to
1315 an expected-output file under Lib/test/output/, no longer stop at
1316 the first mismatch. Instead the test is run to completion, and a
1317 variant of ndiff-style comparison is used to report all differences.
1318 This is much easier to understand than the previous style of reporting.
1319
1320- The unittest-based standard tests now use regrtest's test_main()
1321 convention, instead of running as a side-effect of merely being
1322 imported. This allows these tests to be run in more natural and
1323 flexible ways as unittests, outside the regrtest framework.
1324
1325- regrtest.py is much better integrated with unittest and doctest now,
1326 especially in regard to reporting errors.
1327
Tim Petersb07352e2001-09-08 01:25:47 +00001328Windows
1329
Guido van Rossum624c8af2001-09-18 15:21:04 +00001330- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001331 that support it (NTFS under Windows 2000). See "What's New in
1332 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001333
Tim Petersb07352e2001-09-08 01:25:47 +00001334
Tim Petersedc99312001-08-22 21:36:50 +00001335What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001336Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001337===========================
1338
1339Core
1340
Tim Peters9fffa3e2001-09-04 05:14:19 +00001341- Conversion of long to float now raises OverflowError if the long is too
1342 big to represent as a C double.
1343
Tim Peters32f453e2001-09-03 08:35:41 +00001344- The 3-argument builtin pow() no longer allows a third non-None argument
1345 if either of the first two arguments is a float, or if both are of
1346 integer types and the second argument is negative (in which latter case
1347 the arguments are converted to float, so this is really the same
1348 restriction).
1349
Tim Peters5d2b77c2001-09-03 05:47:38 +00001350- The builtin dir() now returns more information, and sometimes much
1351 more, generally naming all attributes of an object, and all attributes
1352 reachable from the object via its class, and from its class's base
1353 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1354 an empty list. In 2.2a3,
1355
1356 >>> dir([])
1357 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1358 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1359 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1360 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1361 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1362 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1363 'reverse', 'sort']
1364
1365 dir(module) continues to return only the module's attributes, though.
1366
Tim Petersbdee63f2001-09-02 03:40:59 +00001367- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001368 than raising OverflowError. This is a partial implementation of PEP
1369 237. You can use -Wdefault::OverflowWarning to enable a warning for
1370 this situation, and -Werror::OverflowWarning to revert to the old
1371 OverflowError exception.
1372
Guido van Rossum61c345f2001-09-04 03:26:15 +00001373- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001374 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001375 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1376 -Qold, meaning the / operator has its classic meaning and no
1377 warnings are issued. Using -Qwarn issues a run-time warning about
1378 all uses of classic division for int and long arguments; -Qwarnall
1379 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001380 (for use with fixdiv.py).
1381 [Note: the remainder of this paragraph (preserved below) became
1382 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1383 <obsolete>
1384 Using -Qnew is questionable; it turns on new division by default, but
1385 only in the __main__ module. You can usefully combine -Qwarn or
1386 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1387 warns about classic division everywhere else.
1388 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001389
Tim Petersbdee63f2001-09-02 03:40:59 +00001390- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001391 long, float, str, unicode, and tuple. (The types complex, list and
1392 dictionary can also be subclassed; this was introduced earlier.)
1393 Note that restrictions apply when subclassing immutable built-in
1394 types: you can only affect the value of the instance by overloading
1395 __new__. You can add mutable attributes, and the subclass instances
1396 will have a __dict__ attribute, but you cannot change the "value"
1397 (as implemented by the base class) of an immutable subclass instance
1398 once it is created.
1399
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001400- The dictionary constructor now takes an optional argument, a
1401 mapping-like object, and initializes the dictionary from its
1402 (key, value) pairs.
1403
Tim Petersbdee63f2001-09-02 03:40:59 +00001404- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001405 "cooperative super calls" in a multiple inheritance setting. For an
1406 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1407
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001408- A new built-in type, property, has been added. This enables the
1409 creation of "properties". These are attributes implemented by
1410 getter and setter functions (or only one of these for read-only or
1411 write-only attributes), without the need to override __getattr__.
1412 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001413
Tim Petersbdee63f2001-09-02 03:40:59 +00001414- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001415 liberalized, to allow leading zeroes. Examples of literals now
1416 legal that were SyntaxErrors before:
1417
1418 00.0 0e3 0100j 07.5 00000000000000000008.
1419
Tim Petersbdee63f2001-09-02 03:40:59 +00001420- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001421 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1422
Tim Petersedc99312001-08-22 21:36:50 +00001423Library
1424
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001425- telnetlib includes symbolic names for the options, and support for
1426 setting an option negotiation callback.
1427
Tim Petersa40c7932001-09-05 22:36:56 +00001428- The new C standard no longer requires that math libraries set errno to
1429 ERANGE on overflow. For platform libraries that exploit this new
1430 freedom, Python's overflow-checking was wholly broken. A new overflow-
1431 checking scheme attempts to repair that, but may not be reliable on all
1432 platforms (C doesn't seem to provide anything both useful and portable
1433 in this area anymore).
1434
Martin v. Löwis44f86962001-09-05 13:44:54 +00001435- Asynchronous timeout actions are available through the new class
1436 threading.Timer.
1437
Tim Peters78526162001-09-05 00:53:45 +00001438- math.log and math.log10 now return sensible results for even huge
1439 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1440
Tim Petersbdee63f2001-09-02 03:40:59 +00001441- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001442 currently held. See the docs for the imp module.
1443
Tim Petersbdee63f2001-09-02 03:40:59 +00001444- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001445 dumps containing ints written on platforms where Python ints are 8 bytes.
1446 When read on a box where Python ints are 4 bytes, such values are
1447 converted to Python longs.
1448
Tim Petersbdee63f2001-09-02 03:40:59 +00001449- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001450 code objects is no longer allowed. This plugs a security hole.
1451
Steve Purcell6091cd62001-09-06 16:05:17 +00001452- unittest.TestResult instances no longer store references to tracebacks
1453 generated by test failures. This prevents unexpected dangling references
1454 to objects that should be garbage collected between tests.
1455
Tim Petersedc99312001-08-22 21:36:50 +00001456Tools
1457
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001458- Tools/scripts/fixdiv.py has been added which can be used to fix
1459 division operators as per PEP 238.
1460
Tim Petersedc99312001-08-22 21:36:50 +00001461Build
1462
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001463- If you are an adventurous person using Mac OS X you may want to look at
1464 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1465 application, which can be used for experimenting with Carbon or Cocoa.
1466 Discussion of this on pythonmac-sig, please.
1467
Tim Peters7eea37e2001-09-04 22:08:56 +00001468C API
1469
1470- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001471
Tim Peters9fffa3e2001-09-04 05:14:19 +00001472- Note that PyLong_AsDouble can fail! This has always been true, but no
1473 callers checked for it. It's more likely to fail now, because overflow
1474 errors are properly detected now. The proper way to check:
1475
1476 double x = PyLong_AsDouble(some_long_object);
1477 if (x == -1.0 && PyErr_Occurred()) {
1478 /* The conversion failed. */
1479 }
1480
Tim Petersbdee63f2001-09-02 03:40:59 +00001481- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001482 compile but will not participate in GC. To upgrade an extension
1483 module:
1484
1485 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001486
Neil Schemenauer4042c692001-08-30 15:38:01 +00001487 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1488 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001489
Neil Schemenauer4042c692001-08-30 15:38:01 +00001490 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1491 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001492
Neil Schemenauer4042c692001-08-30 15:38:01 +00001493 - remove PyGC_HEAD_SIZE from object size calculations
1494
1495 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1496
Tim Petersbdee63f2001-09-02 03:40:59 +00001497- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001498 These can be used safely to construct string objects from a
1499 sprintf-style format string (similar to the format string supported
1500 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001501
Tim Petersedc99312001-08-22 21:36:50 +00001502New platforms
1503
Tim Petersb7da0902001-09-02 23:01:43 +00001504- Stephen Hansen contributed patches sufficient to get a clean compile
1505 under Borland C (Windows), but he reports problems running it and ran
1506 out of time to complete the port. Volunteers? Expect a MemoryError
1507 when importing the types module; this is probably shallow, and
1508 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001509
Tim Petersedc99312001-08-22 21:36:50 +00001510Tests
1511
1512Windows
1513
Tim Peters6e13a562001-09-06 00:32:15 +00001514- Large file support is now enabled on Win32 platforms as well as on
1515 Win64. This means that, for example, you can use f.tell() and f.seek()
1516 to manipulate files larger than 2 gigabytes (provided you have enough
1517 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001518 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1519 filesize limit, and large file support makes no difference there.
1520 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1521 NTFS has no practical limit on file size, and files of any size can be
1522 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001523
Tim Petersbdee63f2001-09-02 03:40:59 +00001524- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001525 points to command.com (patch from Brian Quinlan).
1526
Tim Petersedc99312001-08-22 21:36:50 +00001527
Tim Peters20f51a72001-07-21 02:31:40 +00001528What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001529Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001530===========================
1531
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001532Build
1533
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001534- Tim Peters developed a brand new Windows installer using Wise 8.1,
1535 generously donated to us by Wise Solutions.
1536
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001537- configure supports a new option --enable-unicode, with the values
1538 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1539 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001540
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001541- A new configure option --enable-framework builds a Mac OS X framework,
1542 which "make frameworkinstall" will install. This provides a starting
1543 point for more mac-like functionality, join pythonmac-sig@python.org
1544 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001545
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001546- The NeXT platform is no longer supported.
1547
1548- The `new' module is now statically linked.
1549
Tim Peters0afb6092001-08-15 06:06:44 +00001550Tools
1551
1552- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001553 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001554 the module docstring for details.
1555
Tim Peters20f51a72001-07-21 02:31:40 +00001556Tests
1557
Tim Peters5e824c32001-08-12 22:25:01 +00001558- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001559 platforms, allowing to give clearer test result output. regrtest
1560 also has optional --use/-u switch to run normally disabled tests
1561 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001562
Tim Peters20f51a72001-07-21 02:31:40 +00001563- Several new tests in the standard test suite, with special thanks to
1564 Nick Mathewson.
1565
1566Core
1567
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001568- The floor division operator // has been added as outlined in PEP
1569 238. The / operator still provides classic division (and will until
1570 Python 3.0) unless "from __future__ import division" is included, in
1571 which case the / operator will provide true division. The operator
1572 module provides truediv() and floordiv() functions. Augmented
1573 assignment variants are included, as are the equivalent overloadable
1574 methods and C API methods. See the PEP for a full discussion:
1575 <http://python.sf.net/peps/pep-0238.html>
1576
Tim Peters6cd6a822001-08-17 22:11:27 +00001577- Future statements are now effective in simulated interactive shells
1578 (like IDLE). This should "just work" by magic, but read Michael
1579 Hudson's "Future statements in simulated shells" PEP 264 for full
1580 details: <http://python.sf.net/peps/pep-0264.html>.
1581
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001582- The type/class unification (PEP 252-253) was integrated into the
1583 trunk and is not so tentative any more (the exact specification of
1584 some features is still tentative). A lot of work has done on fixing
1585 bugs and adding robustness and features (performance still has to
1586 come a long way).
1587
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001588- Warnings about a mismatch in the Python API during extension import
1589 now use the Python warning framework (which makes it possible to
1590 write filters for these warnings).
1591
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001592- A function's __dict__ (aka func_dict) will now always be a
1593 dictionary. It used to be possible to delete it or set it to None,
1594 but now both actions raise TypeErrors. It is still legal to set it
1595 to a dictionary object. Getting func.__dict__ before any attributes
1596 have been assigned now returns an empty dictionary instead of None.
1597
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001598- A new command line option, -E, was added which disables the use of
1599 all environment variables, or at least those that are specifically
1600 significant to Python. Usually those have a name starting with
1601 "PYTHON". This was used to fix a problem where the tests fail if
1602 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1603 older distribution.
1604
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001605Library
1606
Tim Peters5e824c32001-08-12 22:25:01 +00001607- New class Differ and new functions ndiff() and restore() in difflib.py.
1608 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001609 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001610
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001611- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1612 value using the minimal quoting required for the value; more
1613 reliable than using xml.sax.saxutils.escape() for attribute values.
1614
1615- Readline completion support for cmd.Cmd was added.
1616
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001617- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1618
1619- Added function threading.BoundedSemaphore()
1620
1621- Added Ka-Ping Yee's cgitb.py module.
1622
1623- The `new' module now exposes the CO_xxx flags.
1624
Martin v. Löwis560da622001-11-24 09:24:51 +00001625- The gc module offers the get_referents function.
1626
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001627New platforms
1628
1629C API
1630
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001631- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1632 which provide a cross-platform implementations for the
1633 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1634 the standard sprintf() and vsprintf() C lib APIs, these versions
1635 apply bounds checking on the used buffer which enhances protection
1636 against buffer overruns.
1637
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001638- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001639 and extensions using different Unicode widths is rendered next to
1640 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001641 will result in an ImportError. Unicode extensions writers must make
1642 sure to check the Unicode width compatibility in their extensions by
1643 using at least one of the mangled Unicode APIs in the extension.
1644
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001645- Two new flags METH_NOARGS and METH_O are available in method definition
1646 tables to simplify implementation of methods with no arguments and a
1647 single untyped argument. Calling such methods is more efficient than
1648 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1649 deprecated.
1650
Tim Petersc1731372001-08-04 08:12:36 +00001651Windows
1652
1653- "import module" now compiles module.pyw if it exists and nothing else
1654 relevant is found.
1655
Tim Peters20f51a72001-07-21 02:31:40 +00001656
Guido van Rossum55a78992001-07-17 17:22:32 +00001657What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001658Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001659===========================
1660
1661Core
Tim Petersa814db52001-05-14 07:05:58 +00001662
Tim Peters6d6c1a32001-08-02 04:15:00 +00001663- TENTATIVELY, a large amount of code implementing much of what's
1664 described in PEP 252 (Making Types Look More Like Classes) and PEP
1665 253 (Subtyping Built-in Types) was added. This will be released
1666 with Python 2.2a1. Documentation will be provided separately
1667 through http://www.python.org/2.2/. The purpose of releasing this
1668 with Python 2.2a1 is to test backwards compatibility. It is
1669 possible, though not likely, that a decision is made not to release
1670 this code as part of 2.2 final, if any serious backwards
1671 incompapatibilities are found during alpha testing that cannot be
1672 repaired.
1673
Guido van Rossum55a78992001-07-17 17:22:32 +00001674- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001675 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001676 more 'yield' statements. See PEP 255. Since this adds a new
1677 keyword to the language, this feature must be enabled by including a
1678 future statement: "from __future__ import generators" (see PEP 236).
1679 Generators will become a standard feature in a future release
1680 (probably 2.3). Without this future statement, 'yield' remains an
1681 ordinary identifier, but a warning is issued each time it is used.
1682 (These warnings currently don't conform to the warnings framework of
1683 PEP 230; we intend to fix this in 2.2a2.)
1684
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001685- The UTF-16 codec was modified to be more RFC compliant. It will now
1686 only remove BOM characters at the start of the string and then
1687 only if running in native mode (UTF-16-LE and -BE won't remove a
1688 leading BMO character).
1689
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001690- Strings now have a new method .decode() to complement the already
1691 existing .encode() method. These two methods provide direct access
1692 to the corresponding decoders and encoders of the registered codecs.
1693
1694 To enhance the usability of the .encode() method, the special
1695 casing of Unicode object return values was dropped (Unicode objects
1696 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001697
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001698 Both methods will now return whatever the codec in charge of the
1699 requested encoding returns as object, e.g. Unicode codecs will
1700 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1701 will return u"äöü"). This enables codec writer to create codecs
1702 for various simple to use conversions.
1703
1704 New codecs were added to demonstrate these new features (the .encode()
1705 and .decode() columns indicate the type of the returned objects):
1706
1707 Name | .encode() | .decode() | Description
1708 ----------------------------------------------------------------------
1709 uu | string | string | UU codec (e.g. for email)
1710 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001711 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001712 zlib | string | string | zlib compression
1713 hex | string | string | 2-byte hex codec
1714 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1715
Mark Hammond2a0af792001-05-14 03:09:36 +00001716- Some operating systems now support the concept of a default Unicode
1717 encoding for file system operations. Notably, Windows supports 'mbcs'
1718 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001719 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001720 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001721
1722 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001723 functions that return filenames (such as os.listdir()) to return Python
1724 string objects pre-encoded using the default file system encoding for
1725 the platform. As this encoding is likely to be different from Python's
1726 default encoding, converting this name to a Unicode object before passing
1727 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001728 would attempt to use its default encoding (generally ASCII) rather than
1729 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001730
Tim Petersa814db52001-05-14 07:05:58 +00001731 In general, this change simply removes surprises when working with
1732 Unicode and the file system, making these operations work as you expect,
1733 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001734 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001735
Tim Peters61dff2b2001-05-08 15:43:37 +00001736- Float (and complex) literals in source code were evaluated to full
1737 precision only when running from a .py file; the same code loaded from a
1738 .pyc (or .pyo) file could suffer numeric differences starting at about the
1739 12th significant decimal digit. For example, on a machine with IEEE-754
1740 floating arithmetic,
1741
1742 x = 9007199254740992.0
1743 print long(x)
1744
1745 printed 9007199254740992 if run directly from .py, but 9007199254740000
1746 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1747 str(float) instead of repr(float) when building code objects. marshal
1748 now uses repr(float) instead, which should reproduce floats to full
1749 machine precision (assuming the platform C float<->string I/O conversion
1750 functions are of good quality).
1751
1752 This may cause floating-point results to change in some cases, and
1753 usually for the better, but may also cause numerically unstable
1754 algorithms to break.
1755
Tim Peters2f228e72001-05-13 00:19:31 +00001756- The implementation of dicts suffers fewer collisions, which has speed
1757 benefits. However, the order in which dict entries appear in dict.keys(),
1758 dict.values() and dict.items() may differ from previous releases for a
1759 given dict. Nothing is defined about this order, so no program should
1760 rely on it. Nevertheless, it's easy to write test cases that rely on the
1761 order by accident, typically because of printing the str() or repr() of a
1762 dict to an "expected results" file. See Lib/test/test_support.py's new
1763 sortdict(dict) function for a simple way to display a dict in sorted
1764 order.
1765
Tim Peters7a3bfc32001-06-12 01:22:22 +00001766- Many other small changes to dicts were made, resulting in faster
1767 operation along the most common code paths.
1768
Guido van Rossum10315822001-05-01 20:54:30 +00001769- Dictionary objects now support the "in" operator: "x in dict" means
1770 the same as dict.has_key(x).
1771
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001772- The update() method of dictionaries now accepts generic mapping
1773 objects. Specifically the argument object must support the .keys()
1774 and __getitem__() methods. This allows you to say, for example,
1775 {}.update(UserDict())
1776
Guido van Rossum10315822001-05-01 20:54:30 +00001777- Iterators were added; this is a generalized way of providing values
1778 to a for loop. See PEP 234. There's a new built-in function iter()
1779 to return an iterator. There's a new protocol to get the next value
1780 from an iterator using the next() method (in Python) or the
1781 tp_iternext slot (in C). There's a new protocol to get iterators
1782 using the __iter__() method (in Python) or the tp_iter slot (in C).
1783 Iterating (i.e. a for loop) over a dictionary generates its keys.
1784 Iterating over a file generates its lines.
1785
Tim Petersf553f892001-05-01 20:45:31 +00001786- The following functions were generalized to work nicely with iterator
1787 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001788 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001789 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1790 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001791 join() method of strings
1792 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001793 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1794 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001795 right-hand side of assignment statements with multiple targets, such as
1796 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001797
Tim Petersd85e1022001-05-11 21:51:48 +00001798- Accessing module attributes is significantly faster (for example,
1799 random.random or os.path or yourPythonModule.yourAttribute).
1800
Tim Peterse63415e2001-05-08 04:38:29 +00001801- Comparing dictionary objects via == and != is faster, and now works even
1802 if the keys and values don't support comparisons other than ==.
1803
Tim Peters95bf9392001-05-10 08:32:44 +00001804- Comparing dictionaries in ways other than == and != is slower: there were
1805 insecurities in the dict comparison implementation that could cause Python
1806 to crash if the element comparison routines for the dict keys and/or
1807 values mutated the dicts. Making the code bulletproof slowed it down.
1808
Tim Peterseb28ef22001-06-02 05:27:19 +00001809- Collisions in dicts are resolved via a new approach, which can help
1810 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001811 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001812 faster now. Thanks to Christian Tismer for pointing out the cause and
1813 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001814
Tim Peters52e155e2001-06-16 05:42:57 +00001815- repr() is much faster for large containers (dict, list, tuple).
1816
1817
Tim Petersa814db52001-05-14 07:05:58 +00001818Library
1819
Fred Drake960fdf92001-07-20 18:38:26 +00001820- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1821 were added to the string module. These a locale-indenpendent
1822 constants, unlike letters, lowercase, and uppercase. These are now
1823 use in appropriate locations in the standard library.
1824
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001825- The flags used in dlopen calls can now be configured using
1826 sys.setdlopenflags and queried using sys.getdlopenflags.
1827
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001828- Fredrik Lundh's xmlrpclib is now a standard library module. This
1829 provides full client-side XML-RPC support. In addition,
1830 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1831 one asyncore-based). Thanks to Eric Raymond for the documentation.
1832
Guido van Rossum643d3912001-07-05 14:46:25 +00001833- The xrange() object is simplified: it no longer supports slicing,
1834 repetition, comparisons, efficient 'in' checking, the tolist()
1835 method, or the start, stop and step attributes. See PEP 260.
1836
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001837- A new function fnmatch.filter to filter lists of file names was added.
1838
Barry Warsawffd674d2001-05-22 16:00:10 +00001839- calendar.py uses month and day names based on the current locale.
1840
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001841- strop is now *really* obsolete (this was announced before with 1.6),
1842 and issues DeprecationWarning when used (except for the four items
1843 that are still imported into string.py).
1844
Tim Petersa814db52001-05-14 07:05:58 +00001845- Cookie.py now sorts key+value pairs by key in output strings.
1846
1847- pprint.isrecursive(object) didn't correctly identify recursive objects.
1848 Now it does.
1849
Tim Peters95b3f782001-05-14 18:39:41 +00001850- pprint functions now much faster for large containers (tuple, list, dict).
1851
Tim Peters7b9542a2001-06-10 23:40:19 +00001852- New 'q' and 'Q' format codes in the struct module, corresponding to C
1853 types "long long" and "unsigned long long" (on Windows, __int64). In
1854 native mode, these can be used only when the platform C compiler supports
1855 these types (when HAVE_LONG_LONG is #define'd by the Python config
1856 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001857 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1858 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001859
Guido van Rossum83213cc2001-06-12 16:48:52 +00001860- The site module installs a new built-in function 'help' that invokes
1861 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1862 it displays a message reminding the user to use 'help()' or
1863 'help(object)'.
1864
Tim Petersa814db52001-05-14 07:05:58 +00001865Tests
1866
1867- New test_mutants.py runs dict comparisons where the key and value
1868 comparison operators mutute the dicts randomly during comparison. This
1869 rapidly causes Python to crash under earlier releases (not for the faint
1870 of heart: it can also cause Win9x to freeze or reboot!).
1871
1872- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001873 pprint.isreadable() return sensible results. Also verifies that simple
1874 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001875
Tim Peters4324aa32001-05-28 22:30:08 +00001876C API
1877
1878- Removed the unused last_is_sticky argument from the internal
1879 _PyTuple_Resize(). If this affects you, you were cheating.
1880
1881
Guido van Rossum55a78992001-07-17 17:22:32 +00001882======================================================================
1883
1884
Guido van Rossumffe13be2001-04-16 18:46:45 +00001885What's New in Python 2.1 (final)?
1886=================================
1887
1888We only changed a few things since the last release candidate, all in
1889Python library code:
1890
1891- A bug in the locale module was fixed that affected locales which
1892 define no grouping for numeric formatting.
1893
1894- A few bugs in the weakref module's implementations of weak
1895 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1896 and the test suite was updated to check for these bugs.
1897
1898- An old bug in the os.path.walk() function (introduced in Python
1899 2.0!) was fixed: a non-existent file would cause an exception
1900 instead of being ignored.
1901
1902- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1903 PyChecker.
1904
1905
Guido van Rossum5b08f132001-04-16 02:05:23 +00001906What's New in Python 2.1c2?
1907===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001908
Guido van Rossum5b08f132001-04-16 02:05:23 +00001909A flurry of small changes, and one showstopper fixed in the nick of
1910time made it necessary to release another release candidate. The list
1911here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001912
Guido van Rossum5b08f132001-04-16 02:05:23 +00001913Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001914
Guido van Rossum5b08f132001-04-16 02:05:23 +00001915- Tim discovered a nasty bug in the dictionary code, caused by
1916 PyDict_Next() calling dict_resize(), and the GC code's use of
1917 PyDict_Next() violating an assumption in dict_items(). This was
1918 fixed with considerable amounts of band-aid, but the net effect is a
1919 saner and more robust implementation.
1920
1921- Made a bunch of symbols static that were accidentally global.
1922
1923Build and Ports
1924
1925- The setup.py script didn't check for a new enough version of zlib
1926 (1.1.3 is needed). Now it does.
1927
1928- Changed "make clean" target to also remove shared libraries.
1929
1930- Added a more general warning about the SGI Irix optimizer to README.
1931
1932Library
1933
1934- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1935 omitted the slash between host and file.html.
1936
1937- The mailbox module's _Mailbox class contained a completely broken
1938 and undocumented seek() method. Ripped it out.
1939
1940- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1941 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1942
1943- Fixed a few last-minute bugs in unittest.
1944
1945Extensions
1946
1947- Reverted the patch to the OpenSSL code in socketmodule.c to support
1948 RAND_status() and the EGD, and the subsequent patch that tried to
1949 fix it for pre-0.9.5 versions; the problem with the patch is that on
1950 some systems it issues a warning whenever socket is imported, and
1951 that's unacceptable.
1952
1953Tests
1954
1955- Fixed the pickle tests to work with "import test.test_pickle".
1956
1957- Tweaked test_locale.py to actually run the test Windows.
1958
1959- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1960 not "wb" (which is not a valid mode at all).
1961
1962- Fix pstats browser crashes. Import readline if it exists to make
1963 the user interface nicer.
1964
1965- Add "import thread" to the top of test modules that import the
1966 threading module (test_asynchat and test_threadedtempfile). This
1967 prevents test failures caused by a broken threading module resulting
1968 from a previously caught failed import.
1969
1970- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1971 needed on some platforms (e.g. Solaris 8) when the tests are run
1972 twice in succession.
1973
1974- Skip rather than fail test_sunaudiodev if no audio device is found.
1975
1976
1977What's New in Python 2.1c1?
1978===========================
1979
1980This list was significantly updated when 2.1c2 was released; the 2.1c1
1981release didn't mention most changes that were actually part of 2.1c1:
1982
1983Legal
1984
1985- Copyright was assigned to the Python Software Foundation (PSF) and a
1986 PSF license (very similar to the CNRI license) was added.
1987
1988- The CNRI copyright notice was updated to include 2001.
1989
1990Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001991
Guido van Rossumc9932722001-04-12 02:31:27 +00001992- After a public outcry, assignment to __debug__ is no longer illegal;
1993 instead, a warning is issued. It will become illegal in 2.2.
1994
Guido van Rossum5b08f132001-04-16 02:05:23 +00001995- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1996 "%#x" now always prepends "0x", even if the value is zero.
1997
1998- Fixed some nits in the bytecode compiler.
1999
2000- Fixed core dumps when calling certain kinds of non-functions.
2001
2002- Fixed various core dumps caused by reference count bugs.
2003
2004Build and Ports
2005
2006- Use INSTALL_SCRIPT to install script files.
2007
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002008- New port: SCO Unixware 7, by Billy G. Allie.
2009
Guido van Rossum5b08f132001-04-16 02:05:23 +00002010- Updated RISCOS port.
2011
2012- Updated BeOS port and notes.
2013
2014- Various other porting problems resolved.
2015
2016Library
2017
2018- The TERMIOS and SOCKET modules are now truly obsolete and
2019 unnecessary. Their symbols are incorporated in the termios and
2020 socket modules.
2021
2022- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
2023 better tests for pickling.
2024
2025- threading: make Condition.wait() robust against KeyboardInterrupt.
2026
2027- zipfile: add support to zipfile to support opening an archive
2028 represented by an open file rather than a file name. Fix bug where
2029 the archive was not properly closed. Fixed a bug in this bugfix
2030 where flush() was called for a read-only file.
2031
2032- imputil: added an uninstall() method to the ImportManager.
2033
2034- Canvas: fixed bugs in lower() and tkraise() methods.
2035
2036- SocketServer: API change (added overridable close_request() method)
2037 so that the TCP server can explicitly close the request.
2038
2039- pstats: Eric Raymond added a simple interactive statistics browser,
2040 invoked when the module is run as a script.
2041
2042- locale: fixed a problem in format().
2043
2044- webbrowser: made it work when the BROWSER environment variable has a
2045 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
2046 KDE 2. Fixed some other nits.
2047
2048- unittest: changes to allow using a different exception than
2049 AssertionError, and added a few more function aliases. Some other
2050 small changes.
2051
2052- urllib, urllib2: fixed redirect problems and a coupleof other nits.
2053
2054- asynchat: fixed a critical bug in asynchat that slipped through the
2055 2.1b2 release. Fixed another rare bug.
2056
2057- Fix some unqualified except: clauses (always a bad code example).
2058
2059XML
2060
2061- pyexpat: new API get_version_string().
2062
2063- Fixed some minidom bugs.
2064
2065Extensions
2066
2067- Fixed a core dump in _weakref. Removed the weakref.mapping()
2068 function (it adds nothing to the API).
2069
2070- Rationalized the use of header files in the readline module, to make
2071 it compile (albeit with some warnings) with the very recent readline
2072 4.2, without breaking for earlier versions.
2073
2074- Hopefully fixed a buffering problem in linuxaudiodev.
2075
2076- Attempted a fix to make the OpenSSL support in the socket module
2077 work again with pre-0.9.5 versions of OpenSSL.
2078
2079Tests
2080
2081- Added a test case for asynchat and asyncore.
2082
2083- Removed coupling between tests where one test failing could break
2084 another.
2085
2086Tools
2087
2088- Ping added an interactive help browser to pydoc, fixed some nits
2089 in the rest of the pydoc code, and added some features to his
2090 inspect module.
2091
2092- An updated python-mode.el version 4.1 which integrates Ken
2093 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2094 much nicer in XEmacs and Emacs. When stepping through your program
2095 with pdb, in either the shell window or the *Python* window, the
2096 source file and line will be tracked by an arrow. Very cool!
2097
2098- IDLE: syntax warnings in interactive mode are changed into errors.
2099
2100- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002101 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002102
2103- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002104
Barry Warsaw11e89c72001-04-11 20:37:57 +00002105
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002106What's New in Python 2.1 beta 2?
2107================================
2108
Guido van Rossum053ae352001-03-22 14:17:21 +00002109(Unlisted are many fixed bugs, more documentation, etc.)
2110
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002111Core language, builtins, and interpreter
2112
Guido van Rossum053ae352001-03-22 14:17:21 +00002113- The nested scopes work (enabled by "from __future__ import
2114 nested_scopes") is completed; in particular, the future now extends
2115 into code executed through exec, eval() and execfile(), and into the
2116 interactive interpreter.
2117
2118- When calling a base class method (e.g. BaseClass.__init__(self)),
2119 this is now allowed even if self is not strictly spoken a class
2120 instance (e.g. when using metaclasses or the Don Beaudry hook).
2121
2122- Slice objects are now comparable but not hashable; this prevents
2123 dict[:] from being accepted but meaningless.
2124
2125- Complex division is now calculated using less braindead algorithms.
2126 This doesn't change semantics except it's more likely to give useful
2127 results in extreme cases. Complex repr() now uses full precision
2128 like float repr().
2129
2130- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2131
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002132- It is illegal to assign to the name __debug__, which is set when the
2133 interpreter starts. It is effectively a compile-time constant.
2134
2135- A warning will be issued if a global statement for a variable
2136 follows a use or assignment of that variable.
2137
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002138Standard library
2139
Guido van Rossum053ae352001-03-22 14:17:21 +00002140- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2141 inspired by JUnit), is now part of the standard library. You now
2142 have a choice of two testing frameworks: unittest requires you to
2143 write testcases as separate code, doctest gathers them from
2144 docstrings. Both approaches have their advantages and
2145 disadvantages.
2146
2147- A new module Tix was added, which wraps the Tix extension library
2148 for Tk. With that module, it is not necessary to statically link
2149 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2150 require" command. See Demo/tix/.
2151
2152- tzparse.py is now obsolete.
2153
2154- In gzip.py, the seek() and tell() methods are removed -- they were
2155 non-functional anyway, and it's better if callers can test for their
2156 existence with hasattr().
2157
2158Python/C API
2159
2160- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2161 that's already in the dictionary during a PyDict_Next() iteration.
2162 This used to fail occasionally when a dictionary resize operation
2163 could be triggered that would rehash all the keys. All other
2164 modifications to the dictionary are still off-limits during a
2165 PyDict_Next() iteration!
2166
2167- New extended APIs related to passing compiler variables around.
2168
2169- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2170 implement isinstance() and issubclass().
2171
2172- Py_BuildValue() now has a "D" conversion to create a Python complex
2173 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002174
Fred Drake4e262a92001-03-22 18:26:47 +00002175- Extensions types which support weak references must now set the
2176 field allocated for the weak reference machinery to NULL themselves;
2177 this is done to avoid the cost of checking each object for having a
2178 weakly referencable type in PyObject_INIT(), since most types are
2179 not weakly referencable.
2180
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002181- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2182 free variables and cell variables to and from the frame's f_locals.
2183
2184- Variants of several functions defined in pythonrun.h have been added
2185 to support the nested_scopes future statement. The variants all end
2186 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2187 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2188 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002189 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002190
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002191Distutils
2192
2193- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2194 into the release tree.
2195
Tim Peters0e57abf2001-05-02 07:39:38 +00002196- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002197 (an uninstaller, more customization of the installer's display)
2198
2199- from Jack Jansen: added Mac-specific code to generate a dialog for
2200 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002201 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002202 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002203
2204- added 'platforms' and 'keywords' to the set of metadata that can be
2205 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002206
2207- applied patches from Jason Tishler to make the compiler class work with
2208 Cygwin.
2209
2210
Tim Peters2fe289a2001-03-01 22:19:38 +00002211What's New in Python 2.1 beta 1?
2212================================
Tim Petersd66595f2001-02-04 03:09:53 +00002213
2214Core language, builtins, and interpreter
2215
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002216- Following an outcry from the community about the amount of code
2217 broken by the nested scopes feature introduced in 2.1a2, we decided
2218 to make this feature optional, and to wait until Python 2.2 (or at
2219 least 6 months) to make it standard. The option can be enabled on a
2220 per-module basis by adding "from __future__ import nested_scopes" at
2221 the beginning of a module (before any other statements, but after
2222 comments and an optional docstring). See PEP 236 (Back to the
2223 __future__) for a description of the __future__ statement. PEP 227
2224 (Statically Nested Scopes) has been updated to reflect this change,
2225 and to clarify the semantics in a number of endcases.
2226
2227- The nested scopes code, when enabled, has been hardened, and most
2228 bugs and memory leaks in it have been fixed.
2229
2230- Compile-time warnings are now generated for a number of conditions
2231 that will break or change in meaning when nested scopes are enabled:
2232
2233 - Using "from...import *" or "exec" without in-clause in a function
2234 scope that also defines a lambda or nested function with one or
2235 more free (non-local) variables. The presence of the import* or
2236 bare exec makes it impossible for the compiler to determine the
2237 exact set of local variables in the outer scope, which makes it
2238 impossible to determine the bindings for free variables in the
2239 inner scope. To avoid the warning about import *, change it into
2240 an import of explicitly name object, or move the import* statement
2241 to the global scope; to avoid the warning about bare exec, use
2242 exec...in... (a good idea anyway -- there's a possibility that
2243 bare exec will be deprecated in the future).
2244
2245 - Use of a global variable in a nested scope with the same name as a
2246 local variable in a surrounding scope. This will change in
2247 meaning with nested scopes: the name in the inner scope will
2248 reference the variable in the outer scope rather than the global
2249 of the same name. To avoid the warning, either rename the outer
2250 variable, or use a global statement in the inner function.
2251
Neil Schemenauera35c6882001-02-27 04:45:05 +00002252- An optional object allocator has been included. This allocator is
2253 optimized for Python objects and should be faster and use less memory
2254 than the standard system allocator. It is not enabled by default
2255 because of possible thread safety problems. The allocator is only
2256 protected by the Python interpreter lock and it is possible that some
2257 extension modules require a thread safe allocator. The object
2258 allocator can be enabled by providing the "--with-pymalloc" option to
2259 configure.
2260
Tim Petersd66595f2001-02-04 03:09:53 +00002261Standard library
2262
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002263- pyexpat now detects the expat version if expat.h defines it. A
2264 number of additional handlers are provided, which are only available
2265 since expat 1.95. In addition, the methods SetParamEntityParsing and
2266 GetInputContext of Parser objects are available with 1.95.x
2267 only. Parser objects now provide the ordered_attributes and
2268 specified_attributes attributes. A new module expat.model was added,
2269 which offers a number of additional constants if 1.95.x is used.
2270
2271- xml.dom offers the new functions registerDOMImplementation and
2272 getDOMImplementation.
2273
2274- xml.dom.minidom offers a toprettyxml method. A number of DOM
2275 conformance issues have been resolved. In particular, Element now
2276 has an hasAttributes method, and the handling of namespaces was
2277 improved.
2278
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002279- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2280 getting information about live Python code, and pydoc.py, a module
2281 for interactively converting docstrings to HTML or text.
2282 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002283 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002284 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2285 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002286
Tim Peters1eff7962001-03-01 02:31:33 +00002287- New library module difflib.py, primarily packaging the SequenceMatcher
2288 class at the heart of the popular ndiff.py file-comparison tool.
2289
2290- doctest.py (a framework for verifying Python code examples in docstrings)
2291 is now part of the std library.
2292
Tim Petersd66595f2001-02-04 03:09:53 +00002293Windows changes
2294
Guido van Rossume3955a82001-03-02 14:05:59 +00002295- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2296 small GUI that lets you browse the module docstrings using your
2297 default web browser.
2298
Tim Peters1eff7962001-03-01 02:31:33 +00002299- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2300 Platforms) is implemented. See
2301
2302 http://python.sourceforge.net/peps/pep-0235.html
2303
2304 for full details, especially the "Current Lower-Left Semantics" section.
2305 The new Windows import rules are simpler than before:
2306
2307 A. If the PYTHONCASEOK environment variable exists, same as
2308 before: silently accept the first case-insensitive match of any
2309 kind; raise ImportError if none found.
2310
2311 B. Else search sys.path for the first case-sensitive match; raise
2312 ImportError if none found.
2313
2314 The same rules have been implented on other platforms with case-
2315 insensitive but case-preserving filesystems too (including Cygwin, and
2316 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002317
Tim Peters25a9ce32001-02-19 07:06:36 +00002318- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2319 what it's supposed to do (and does do under NT and 2000) via direct
2320 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002321 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002322 all Win9x systems before.
2323
Tim Peters1eff7962001-03-01 02:31:33 +00002324- Build: Subproject _test (effectively) renamed to _testcapi.
2325
Tim Peters2fe289a2001-03-01 22:19:38 +00002326New platforms
2327
2328- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2329 Thanks to Steven Majewski!
2330
2331- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2332 Tishler!
2333
Guido van Rossum9089b272001-03-02 06:49:50 +00002334- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2335 Schwertberger! See RISCOS/README for more information -- it seems
2336 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002337 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002338
Tim Peters25a9ce32001-02-19 07:06:36 +00002339
Tim Petersd7b5e882001-01-25 03:36:26 +00002340What's New in Python 2.1 alpha 2?
2341=================================
Tim Peters40ead762001-01-27 05:35:26 +00002342
Tim Petersd7b5e882001-01-25 03:36:26 +00002343Core language, builtins, and interpreter
2344
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002345- Scopes nest. If a name is used in a function or class, but is not
2346 local, the definition in the nearest enclosing function scope will
2347 be used. One consequence of this change is that lambda statements
2348 could reference variables in the namespaces where the lambda is
2349 defined. In some unusual cases, this change will break code.
2350
2351 In all previous version of Python, names were resolved in exactly
2352 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002353 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002354 function A is defined within a function B, the names bound in B are
2355 not visible in A. The new rules make names bound in B visible in A,
2356 unless A contains a name binding that hides the binding in B.
2357
2358 Section 4.1 of the reference manual describes the new scoping rules
2359 in detail. The test script in Lib/test/test_scope.py demonstrates
2360 some of the effects of the change.
2361
2362 The new rules will cause existing code to break if it defines nested
2363 functions where an outer function has local variables with the same
2364 name as globals or builtins used by the inner function. Example:
2365
2366 def munge(str):
2367 def helper(x):
2368 return str(x)
2369 if type(str) != type(''):
2370 str = helper(str)
2371 return str.strip()
2372
2373 Under the old rules, the name str in helper() is bound to the
2374 builtin function str(). Under the new rules, it will be bound to
2375 the argument named str and an error will occur when helper() is
2376 called.
2377
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002378- The compiler will report a SyntaxError if "from ... import *" occurs
2379 in a function or class scope. The language reference has documented
2380 that this case is illegal, but the compiler never checked for it.
2381 The recent introduction of nested scope makes the meaning of this
2382 form of name binding ambiguous. In a future release, the compiler
2383 may allow this form when there is no possibility of ambiguity.
2384
Tim Peters40ead762001-01-27 05:35:26 +00002385- repr(string) is easier to read, now using hex escapes instead of octal,
2386 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2387
2388 >>> "\texample \r\n" + chr(0) + chr(255)
2389 '\texample \r\n\x00\xff' # in 2.1
2390 '\011example \015\012\000\377' # in 2.0
2391
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002392- Functions are now compared and hashed by identity, not by value, since
2393 the func_code attribute is writable.
2394
Fred Drakefb9d7122001-02-01 20:00:40 +00002395- Weak references (PEP 205) have been added. This involves a few
2396 changes in the core, an extension module (_weakref), and a Python
2397 module (weakref). The weakref module is the public interface. It
2398 includes support for "explicit" weak references, proxy objects, and
2399 mappings with weakly held values.
2400
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002401- A 'continue' statement can now appear in a try block within the body
2402 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002403 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002404
Tim Petersd7b5e882001-01-25 03:36:26 +00002405Standard library
2406
Barry Warsaw30dbd142001-01-31 22:14:01 +00002407- mailbox.py now has a new class, PortableUnixMailbox which is
2408 identical to UnixMailbox but uses a more portable scheme for
2409 determining From_ separators. Also, the constructors for all the
2410 classes in this module have a new optional `factory' argument, which
2411 is a callable used when new message classes must be instantiated by
2412 the next() method.
2413
Tim Petersd7b5e882001-01-25 03:36:26 +00002414- random.py is now self-contained, and offers all the functionality of
2415 the now-deprecated whrandom.py. See the docs for details. random.py
2416 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002417 and restoring the internal state of the generator; and jumpahead(n),
2418 for quickly forcing the internal state to be the same as if n calls to
2419 random() had been made. The latter is particularly useful for multi-
2420 threaded programs, creating one instance of the random.Random() class for
2421 each thread, then using .jumpahead() to force each instance to use a
2422 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002423
Tim Peters0de88fc2001-02-01 04:59:18 +00002424- random.py's seed() function is new. For bit-for-bit compatibility with
2425 prior releases, use the whseed function instead. The new seed function
2426 addresses two problems: (1) The old function couldn't produce more than
2427 about 2**24 distinct internal states; the new one about 2**45 (the best
2428 that can be done in the Wichmann-Hill generator). (2) The old function
2429 sometimes produced identical internal states when passed distinct
2430 integers, and there was no simple way to predict when that would happen;
2431 the new one guarantees to produce distinct internal states for all
2432 arguments in [0, 27814431486576L).
2433
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002434- The socket module now supports raw packets on Linux. The socket
2435 family is AF_PACKET.
2436
Tim Peters9ea17ac2001-02-02 05:57:15 +00002437- test_capi.py is a start at running tests of the Python C API. The tests
2438 are implemented by the new Modules/_testmodule.c.
2439
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002440- A new extension module, _symtable, provides provisional access to the
2441 internal symbol table used by the Python compiler. A higher-level
2442 interface will be added on top of _symtable in a future release.
2443
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002444- Removed the obsolete soundex module.
2445
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002446- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2447 the isSameNode method; NamedNodeMap the get method.
2448
2449- xml.sax.expatreader supports the lexical handler property; it
2450 generates comment, startCDATA, and endCDATA events.
2451
Tim Petersee826f82001-01-31 19:39:44 +00002452Windows changes
2453
2454- Build procedure: the zlib project is built in a different way that
2455 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002456 the zlib binary used. See PCbuild\readme.txt for details. Your old
2457 zlib-related directories can be deleted; you'll need to download fresh
2458 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002459
Tim Peters9ea17ac2001-02-02 05:57:15 +00002460- Build: New subproject _test for the benefit of test_capi.py (see above).
2461
Tim Petersb16c56f2001-02-02 21:24:51 +00002462- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2463 interface to some Python compiler internals).
2464
2465- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002466 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002467
Tim Petersa3a3a032000-11-30 05:22:44 +00002468What's New in Python 2.1 alpha 1?
2469=================================
2470
2471Core language, builtins, and interpreter
2472
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002473- There is a new Unicode companion to the PyObject_Str() API
2474 called PyObject_Unicode(). It behaves in the same way as the
2475 former, but assures that the returned value is an Unicode object
2476 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002477
Guido van Rossumf98eda02001-01-17 15:54:45 +00002478- The comparison operators support "rich comparison overloading" (PEP
2479 207). C extension types can provide a rich comparison function in
2480 the new tp_richcompare slot in the type object. The cmp() function
2481 and the C function PyObject_Compare() first try the new rich
2482 comparison operators before trying the old 3-way comparison. There
2483 is also a new C API PyObject_RichCompare() (which also falls back on
2484 the old 3-way comparison, but does not constrain the outcome of the
2485 rich comparison to a Boolean result).
2486
2487 The rich comparison function takes two objects (at least one of
2488 which is guaranteed to have the type that provided the function) and
2489 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2490 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2491 object, which may be NotImplemented (in which case the tp_compare
2492 slot function is used as a fallback, if defined).
2493
2494 Classes can overload individual comparison operators by defining one
2495 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002496 __ge__. There are no explicit "reflected argument" versions of
2497 these; instead, __lt__ and __gt__ are each other's reflection,
2498 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2499 reflection (similar at the C level). No other implications are
2500 made; in particular, Python does not assume that == is the Boolean
2501 inverse of !=, or that < is the Boolean inverse of >=. This makes
2502 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002503
2504 Classes or types that want to implement (in)equality tests but not
2505 the ordering operators (i.e. unordered types) should implement ==
2506 and !=, and raise an error for the ordering operators.
2507
Guido van Rossuma88479f2001-01-18 14:28:08 +00002508 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002509 Boolean; e.g. a matrix type might want to return a matrix of bits
2510 for A < B, giving elementwise comparisons. Such types should ensure
2511 that any interpretation of their value in a Boolean context raises
2512 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2513 at the C level) to always raise an exception.
2514
Guido van Rossuma88479f2001-01-18 14:28:08 +00002515- Complex numbers use rich comparisons to define == and != but raise
2516 an exception for <, <=, > and >=. Unfortunately, this also means
2517 that cmp() of two complex numbers raises an exception when the two
2518 numbers differ. Since it is not mathematically meaningful to compare
2519 complex numbers except for equality, I hope that this doesn't break
2520 too much code.
2521
Tim Peters3389f192001-02-18 08:48:49 +00002522- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002523 not defined by the language, other than that it's arbitrary but
2524 consistent (see the Reference Manual). An implementation detail changed
2525 in 2.1a1 such that None now compares less than any other object. Code
2526 relying on this new behavior (like code that relied on the previous
2527 behavior) does so at its own risk.
2528
Barry Warsaw573b5412001-01-15 20:43:18 +00002529- Functions and methods now support getting and setting arbitrarily
2530 named attributes (PEP 232). Functions have a new __dict__
2531 (a.k.a. func_dict) which hold the function attributes. Methods get
2532 and set attributes on their underlying im_func. It is a TypeError
2533 to set an attribute on a bound method.
2534
Guido van Rossum051e3352001-01-15 19:11:10 +00002535- The xrange() object implementation has been improved so that
2536 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2537 limitation that in this case len(xrange(sys.maxint)) can't be
2538 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2539 work fine as long as the index i doesn't actually reach 2**31.
2540 (Python uses regular ints for sequence and string indices; fixing
2541 that is much more work.)
2542
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002543- Two changes to from...import:
2544
Guido van Rossumba381232001-02-03 15:06:40 +00002545 1) "from M import X" now works even if (after loading module M)
2546 sys.modules['M'] is not a real module; it's basically a getattr()
2547 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002548
2549 2) "from M import *" now looks for M.__all__ to decide which names to
2550 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2551 filters out names starting with '_' as before. Whether or not
2552 __all__ exists, there's no restriction on the type of M.
2553
Guido van Rossumf61f1662001-01-10 20:13:55 +00002554- File objects have a new method, xreadlines(). This is the fastest
2555 way to iterate over all lines in a file:
2556
2557 for line in file.xreadlines():
2558 ...do something to line...
2559
2560 See the xreadlines module (mentioned below) for how to do this for
2561 other file-like objects.
2562
2563- Even if you don't use file.xreadlines(), you may expect a speedup on
2564 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002565 quite a bit in platform-specific ways: on systems (like Linux) that
2566 support flockfile(), getc_unlocked(), and funlockfile(), those are
2567 used by default. On systems (like Windows) without getc_unlocked(),
2568 a complicated (but still thread-safe) method using fgets() is used by
2569 default.
2570
Tim Petersd52269b2001-01-25 06:23:18 +00002571 You can force use of the fgets() method by #define'ing
2572 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002573 getc_unlocked()).
2574
Tim Petersd52269b2001-01-25 06:23:18 +00002575 You can force fgets() not to be used by #define'ing
2576 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002577 test_bufio.py fails -- and let us know if it does!).
2578
2579- In addition, the fileinput module, while still slower than the other
2580 methods on most platforms, has been sped up too, by using
2581 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002582
2583- Support for run-time warnings has been added, including a new
2584 command line option (-W) to specify the disposition of warnings.
2585 See the description of the warnings module below.
2586
2587- Extensive changes have been made to the coercion code. This mostly
2588 affects extension modules (which can now implement mixed-type
2589 numerical operators without having to use coercion), but
2590 occasionally, in boundary cases the coercion semantics have changed
2591 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002592 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002593 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002594 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002595
Guido van Rossumf98eda02001-01-17 15:54:45 +00002596- In connection with the coercion changes, a new built-in singleton
2597 object, NotImplemented is defined. This can be returned for
2598 operations that wish to indicate they are not implemented for a
2599 particular combination of arguments. From C, this is
2600 Py_NotImplemented.
2601
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002602- The interpreter accepts now bytecode files on the command line even
2603 if they do not have a .pyc or .pyo extension. On Linux, after executing
2604
Martin v. Löwise214baa2001-02-04 22:37:56 +00002605import imp,sys,string
2606magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2607reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2608open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002609
2610 any byte code file can be used as an executable (i.e. as an argument
2611 to execve(2)).
2612
Tim Peters9940b802000-12-01 07:59:35 +00002613- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002614 character. In 1.6 and earlier, they never produced a sign,
2615 and raised an error if the value of the long was too large
2616 to fit in a Python int. In 2.0, they produced a sign if and
2617 only if too large to fit in an int. This was inconsistent
2618 across platforms (because the size of an int varies across
2619 platforms), and inconsistent with hex() and oct(). Example:
2620
2621 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002622 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002623 'ffffffbe' # in 2.0 and before, on 32-bit machines
2624 >>> hex(-0x42L)
2625 '-0x42L' # in all versions of Python
2626
Tim Peters9940b802000-12-01 07:59:35 +00002627 The behavior of %d formats for negative Python longs remains
2628 the same as in 2.0 (although in 1.6 and before, they raised
2629 an error if the long didn't fit in a Python int).
2630
2631 %u formats don't make sense for Python longs, but are allowed
2632 and treated the same as %d in 2.1. In 2.0, a negative long
2633 formatted via %u produced a sign if and only if too large to
2634 fit in an int. In 1.6 and earlier, a negative long formatted
2635 via %u raised an error if it was too big to fit in an int.
2636
Guido van Rossum3661d392000-12-12 22:10:31 +00002637- Dictionary objects have an odd new method, popitem(). This removes
2638 an arbitrary item from the dictionary and returns it (in the form of
2639 a (key, value) pair). This can be useful for algorithms that use a
2640 dictionary as a bag of "to do" items and repeatedly need to pick one
2641 item. Such algorithms normally end up running in quadratic time;
2642 using popitem() they can usually be made to run in linear time.
2643
Tim Peters36cdad12000-12-29 02:06:45 +00002644Standard library
2645
Thomas Woutersfe385252001-01-19 23:16:56 +00002646- In the time module, the time argument to the functions strftime,
2647 localtime, gmtime, asctime and ctime is now optional, defaulting to
2648 the current time (in the local timezone).
2649
Guido van Rossumda91f222001-01-15 16:36:08 +00002650- The ftplib module now defaults to passive mode, which is deemed a
2651 more useful default given that clients are often inside firewalls
2652 these days. Note that this could break if ftplib is used to connect
2653 to a *server* that is inside a firewall, from outside; this is
2654 expected to be a very rare situation. To fix that, you can call
2655 ftp.set_pasv(0).
2656
Martin v. Löwis10a27872001-01-13 09:54:41 +00002657- The module site now treats .pth files not only for path configuration,
2658 but also supports extensions to the initialization code: Lines starting
2659 with import are executed.
2660
Guido van Rossumf61f1662001-01-10 20:13:55 +00002661- There's a new module, warnings, which implements a mechanism for
2662 issuing and filtering warnings. There are some new built-in
2663 exceptions that serve as warning categories, and a new command line
2664 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2665 turns warnings into errors). warnings.warn(message[, category])
2666 issues a warning message; this can also be called from C as
2667 PyErr_Warn(category, message).
2668
2669- A new module xreadlines was added. This exports a single factory
2670 function, xreadlines(). The intention is that this code is the
2671 absolutely fastest way to iterate over all lines in an open
2672 file(-like) object:
2673
2674 import xreadlines
2675 for line in xreadlines.xreadlines(file):
2676 ...do something to line...
2677
2678 This is equivalent to the previous the speed record holder using
2679 file.readlines(sizehint). Note that if file is a real file object
2680 (as opposed to a file-like object), this is equivalent:
2681
2682 for line in file.xreadlines():
2683 ...do something to line...
2684
Tim Peters36cdad12000-12-29 02:06:45 +00002685- The bisect module has new functions bisect_left, insort_left,
2686 bisect_right and insort_right. The old names bisect and insort
2687 are now aliases for bisect_right and insort_right. XXX_right
2688 and XXX_left methods differ in what happens when the new element
2689 compares equal to one or more elements already in the list: the
2690 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002691 right. Code that doesn't care where equal elements end up should
2692 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002693
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002694- The new curses.panel module wraps the panel library that forms part
2695 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2696
Guido van Rossumf61f1662001-01-10 20:13:55 +00002697- The SocketServer module now sets the allow_reuse_address flag by
2698 default in the TCPServer class.
2699
2700- A new function, sys._getframe(), returns the stack frame pointer of
2701 the caller. This is intended only as a building block for
2702 higher-level mechanisms such as string interpolation.
2703
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002704- The pyexpat module supports a number of new handlers, which are
2705 available only in expat 1.2. If invocation of a callback fails, it
2706 will report an additional frame in the traceback. Parser objects
2707 participate now in garbage collection. If expat reports an unknown
2708 encoding, pyexpat will try to use a Python codec; that works only
2709 for single-byte charsets. The parser type objects is exposed as
2710 XMLParserObject.
2711
2712- xml.dom now offers standard definitions for symbolic node type and
2713 exception code constants, and a hierarchy of DOM exceptions. minidom
2714 was adjusted to use them.
2715
2716- The conformance of xml.dom.minidom to the DOM specification was
2717 improved. It detects a number of additional error cases; the
2718 previous/next relationship works even when the tree is modified;
2719 Node supports the normalize() method; NamedNodeMap, DocumentType and
2720 DOMImplementation classes were added; Element supports the
2721 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2722 method.
2723
Guido van Rossumf61f1662001-01-10 20:13:55 +00002724Build issues
2725
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002726- For Unix (and Unix-compatible) builds, configuration and building of
2727 extension modules is now greatly automated. Rather than having to
2728 edit the Modules/Setup file to indicate which modules should be
2729 built and where their include files and libraries are, a
2730 distutils-based setup.py script now takes care of building most
2731 extension modules. All extension modules built this way are built
2732 as shared libraries. Only a few modules that must be linked
2733 statically are still listed in the Setup file; you won't need to
2734 edit their configuration.
2735
2736- Python should now build out of the box on Cygwin. If it doesn't,
2737 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002738
2739- Python now always uses its own (renamed) implementation of getopt()
2740 -- there's too much variation among C library getopt()
2741 implementations.
2742
2743- C++ compilers are better supported; the CXX macro is always set to a
2744 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002745
Tim Petersd92dfe02000-12-12 01:18:41 +00002746Windows changes
2747
2748- select module: By default under Windows, a select() call
2749 can specify no more than 64 sockets. Python now boosts
2750 this Microsoft default to 512. If you need even more than
2751 that, see the MS docs (you'll need to #define FD_SETSIZE
2752 and recompile Python from source).
2753
Guido van Rossumf61f1662001-01-10 20:13:55 +00002754- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2755 subdirectory is no more!
2756
Tim Petersa3a3a032000-11-30 05:22:44 +00002757
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002758What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002759=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002760
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002761Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002762changes are in the file HISTORY. If you are making the jump directly
2763from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2764HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002765
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002766Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2767the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2768http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002769
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002770--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002771
2772======================================================================
2773
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002774What's new in 2.0 (since release candidate 1)?
2775==============================================
2776
2777Standard library
2778
2779- The copy_reg module was modified to clarify its intended use: to
2780 register pickle support for extension types, not for classes.
2781 pickle() will raise a TypeError if it is passed a class.
2782
2783- Fixed a bug in gettext's "normalize and expand" code that prevented
2784 it from finding an existing .mo file.
2785
2786- Restored support for HTTP/0.9 servers in httplib.
2787
Tim Peters989b7b92000-10-16 20:24:53 +00002788- The math module was changed to stop raising OverflowError in case of
2789 underflow, and return 0 instead in underflow cases. Whether Python
2790 used to raise OverflowError in case of underflow was platform-
2791 dependent (it did when the platform math library set errno to ERANGE
2792 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002793
2794- Fixed a bug in StringIO that occurred when the file position was not
2795 at the end of the file and write() was called with enough data to
2796 extend past the end of the file.
2797
2798- Fixed a bug that caused Tkinter error messages to get lost on
2799 Windows. The bug was fixed by replacing direct use of
2800 interp->result with Tcl_GetStringResult(interp).
2801
2802- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2803 redirect response.
2804
2805- Several changes were made to distutils: Some debugging code was
2806 removed from util. Fixed the installer used when an external zip
2807 program (like WinZip) is not found; the source code for this
2808 installer is in Misc/distutils. check_lib() was modified to behave
2809 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2810 test for whether installed modules are on sys.path was changed to
2811 use both normcase() and normpath().
2812
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002813- Several minor bugs were fixed in the xml package (the minidom,
2814 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002815
2816- The regression test driver (regrtest.py) behavior when invoked with
2817 -l changed: It now reports a count of objects that are recognized as
2818 garbage but not freed by the garbage collector.
2819
Tim Peters989b7b92000-10-16 20:24:53 +00002820- The regression test for the math module was changed to test
2821 exceptional behavior when the test is run in verbose mode. Python
2822 cannot yet guarantee consistent exception behavior across platforms,
2823 so the exception part of test_math is run only in verbose mode, and
2824 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002825
2826Internals
2827
2828- PyOS_CheckStack() has been disabled on Win64, where it caused
2829 test_sre to fail.
2830
2831Build issues
2832
2833- Changed compiler flags, so that gcc is always invoked with -Wall and
2834 -Wstrict-prototypes. Users compiling Python with GCC should see
2835 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002836 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002837 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002838
Tim Petersa3a3a032000-11-30 05:22:44 +00002839- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002840
2841Tools and other miscellany
2842
2843- The compiler in Tools/compiler was updated to support the new
2844 language features introduced in 2.0: extended print statement, list
2845 comprehensions, and augmented assignments. The new compiler should
2846 also be backwards compatible with Python 1.5.2; the compiler will
2847 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002848 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002849
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002850What's new in 2.0 release candidate 1 (since beta 2)?
2851=====================================================
2852
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002853What is release candidate 1?
2854
2855We believe that release candidate 1 will fix all known bugs that we
2856intend to fix for the 2.0 final release. This release should be a bit
2857more stable than the previous betas. We would like to see even more
2858widespread testing before the final release, so we are producing this
2859release candidate. The final release will be exactly the same unless
2860any show-stopping (or brown bag) bugs are found by testers of the
2861release candidate.
2862
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002863All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002864to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002865
2866Core language, builtins, and interpreter
2867
2868- A bug that caused crashes when __coerce__ was used with augmented
2869 assignment, e.g. +=, was fixed.
2870
2871- Raise ZeroDivisionError when raising zero to a negative number,
2872 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2873 power operator and the result of math.pow(0.0, -2.0) will vary by
2874 platform. On Linux, it raises a ValueError.
2875
2876- A bug in Unicode string interpolation was fixed that occasionally
2877 caused errors with formats including "%%". For example, the
2878 following expression "%% %s" % u"abc" no longer raises a TypeError.
2879
2880- Compilation of deeply nested expressions raises MemoryError instead
2881 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2882
2883- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2884 rendering them useless. They are now written in binary mode again.
2885
2886Standard library
2887
2888- Keyword arguments are now accepted for most pattern and match object
2889 methods in SRE, the standard regular expression engine.
2890
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002891- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002892 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002893
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002894- Several bugs in the Unicode handling and error handling in _tkinter
2895 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002896
2897- Fix memory management errors in Merge() and Tkapp_Call() routines.
2898
2899- Several changes were made to cStringIO to make it compatible with
2900 the file-like object interface and with StringIO. If operations are
2901 performed on a closed object, an exception is raised. The truncate
2902 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002903 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002904
2905- There were many changes made to the linuxaudiodev module and its
2906 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002907 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002908
2909 Note that this module is named poorly, because it should work
2910 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002911 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002912
2913 The module now raises exceptions when errors occur instead of
2914 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2915 audio) and defines a getptr() method that calls the
2916 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2917
2918- The library_version attribute, introduced in an earlier beta, was
2919 removed because it can not be supported with early versions of the C
2920 readline library, which provides no way to determine the version at
2921 compile-time.
2922
2923- The binascii module is now enabled on Win64.
2924
Tim Peters46446d62000-10-09 21:19:31 +00002925- tokenize.py no longer suffers "recursion depth" errors when parsing
2926 programs with very long string literals.
2927
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002928Internals
2929
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002930- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002931 which is called when the interpreter starts up to determine where
2932 the standard library is installed. These vulnerabilities affect all
2933 previous versions of Python and can be exploited by setting very
2934 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2935 setuid Python script, although use of the wrapper in
2936 Misc/setuid-prog.c will eliminate the vulnerability.
2937
2938- Fixed garbage collection bugs in instance creation that were
2939 triggered when errors occurred during initialization. The solution,
2940 applied in cPickle and in PyInstance_New(), is to call
2941 PyObject_GC_Init() after the initialization of the object's
2942 container attributes is complete.
2943
2944- pyexpat adds definitions of PyModule_AddStringConstant and
2945 PyModule_AddObject if the Python version is less than 2.0, which
2946 provides compatibility with PyXML on Python 1.5.2.
2947
2948- If the platform has a bogus definition for LONG_BIT (the number of
2949 bits in a long), an error will be reported at compile time.
2950
2951- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2952 collection crashes and possibly other, unreported crashes.
2953
2954- Fixed a memory leak in _PyUnicode_Fini().
2955
2956Build issues
2957
2958- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002959 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002960 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002961
2962- The mmap.PAGESIZE constant is now initialized using sysconf when
2963 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2964
2965- The md5 file should now compile on all platforms.
2966
2967- The select module now compiles on platforms that do not define
2968 POLLRDNORM and related constants.
2969
2970- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002971 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002972
Jeremy Hylton10921202000-10-09 18:34:12 +00002973- BeOS: A number of changes were made to the build and installation
2974 process. ar-fake now operates on a directory of object files.
2975 dl_export.h is gone, and its macros now appear on the mwcc command
2976 line during build on PPC BeOS.
2977
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002978- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002979 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002980
2981- Cygwin: Support for shared libraries, Tkinter, and sockets.
2982
2983- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2984
2985Tools and other miscellany
2986
2987- Removed debugging prints from main used with freeze.
2988
Tim Peters46446d62000-10-09 21:19:31 +00002989- IDLE auto-indent no longer crashes when it encounters Unicode
2990 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002991
2992What's new in 2.0 beta 2 (since beta 1)?
2993========================================
2994
2995Core language, builtins, and interpreter
2996
Tim Peters482c0212000-09-26 06:33:09 +00002997- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002998 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002999
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003000- Add -h and -V command line options to print the usage message and
3001 Python version number and exit immediately.
3002
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003003- eval() and exec accept Unicode objects as code parameters.
3004
3005- getattr() and setattr() now also accept Unicode objects for the
3006 attribute name, which are converted to strings using the default
3007 encoding before lookup.
3008
3009- Multiplication on string and Unicode now does proper bounds
3010 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
3011 string is too long."
3012
3013- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00003014 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003015
Jeremy Hylton1b618592000-09-26 05:32:36 +00003016
3017Standard library and extensions
3018
Guido van Rossum5b08f132001-04-16 02:05:23 +00003019- socket module: the OpenSSL code now adds support for RAND_status()
3020 and EGD (Entropy Gathering Device).
3021
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003022- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00003023 argument checking; it still takes no arguments.
3024
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003025- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003026
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003027- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003028
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003029- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003030
3031- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003032 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003033
3034- copy: Copy Unicode objects atomically.
3035
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003036- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003037
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003038- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003039
Fred Drake67233bc2000-09-26 16:40:27 +00003040- dbm: Add get() and setdefault() methods to dbm object. Add constant
3041 `library' to module that names the library used. Added doc strings
3042 and method names to error messages. Uses configure to determine
3043 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
3044 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003045
3046- distutils: Update to version 0.9.3.
3047
3048- dl: Add several dl.RTLD_ constants.
3049
3050- fpectl: Now supported on FreeBSD.
3051
3052- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
3053 found by the collector will be saved in gc.garbage. This is useful
3054 for debugging a program that creates reference cycles.
3055
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003056- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003057 of HTTP class. Do not close socket on zero-length response. Do not
3058 crash when server sends invalid content-length header.
3059
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003060- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003061
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003062- marshal: When reading a short, sign-extend on platforms where shorts
3063 are bigger than 16 bits. When reading a long, repair the unportable
3064 sign extension that was being done for 64-bit machines. (It assumed
3065 that signed right shift sign-extends.)
3066
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003067- operator: Add contains(), invert(), __invert__() as aliases for
3068 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003069
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003070- os: Add support for popen2() and popen3() on all platforms where
3071 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003072
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003073- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003074 clicking on a file in Explorer (or passing the file name to the
3075 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003076
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003077- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003078 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003079
3080- pickle: Now raises ValueError when an invalid pickle that contains
3081 a non-string repr where a string repr was expected. This behavior
3082 matches cPickle.
3083
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003084- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003085
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003086- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003087
3088- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003089 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003090 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003091
3092- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003093 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003094
3095- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003096 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003097 few cycles during startup since the first call to
3098 setdefaultencoding() will initialize the codec registry and the
3099 encodings package.
3100
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003101- socket: Support for size hint in readlines() method of object returned
3102 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003103
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003104- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003105 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003106 is followed by whitespace.
3107
Tim Petersa3a3a032000-11-30 05:22:44 +00003108- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003109
3110- struct: Check ranges for bytes and shorts.
3111
3112- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003113 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003114
3115- Tkinter: Image objects are now guaranteed to have unique ids. Set
3116 event.delta to zero if Tk version doesn't support mousewheel.
3117 Removed some debugging prints.
3118
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003119- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003120
Fred Drake67233bc2000-09-26 16:40:27 +00003121- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003122 which works around a bug in Norton AntiVirus 2000 that leads directly
3123 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003124
3125- xml: New version detection code allows PyXML to override standard
3126 XML package if PyXML version is greater than 0.6.1.
3127
Fred Drake64bb3802000-09-26 16:21:35 +00003128- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3129 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3130 tree only for nodes which are sufficiently interesting to a specific
3131 application. Does not provide the HTML-specific extensions. Still
3132 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003133
Fred Drake64bb3802000-09-26 16:21:35 +00003134- xml.sax: SAX 2 support for Python, including all the handler
3135 interfaces needed to process XML 1.0 compliant XML. Some
3136 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003137
Fred Drake64bb3802000-09-26 16:21:35 +00003138- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3139 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003140
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003141
Jeremy Hylton1b618592000-09-26 05:32:36 +00003142C API
3143
3144- Add three new convenience functions for module initialization --
3145 PyModule_AddObject(), PyModule_AddIntConstant(), and
3146 PyModule_AddStringConstant().
3147
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003148- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003149 removed and add #error to Python.h if NULL isn't defined after
3150 #include of stdio.h.
3151
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003152- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003153 backwards compatibility (at the source level) with old extensions.
3154
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003155- A wrapper API was added for signal() and sigaction(). Instead of
3156 either function, always use PyOS_getsig() to get a signal handler
3157 and PyOS_setsig() to set one. A new convenience typedef
3158 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003159
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003160- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003161 internal data buffer and size of a string object -- or the default
3162 encoded version of a Unicode object.
3163
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003164- PyString_Size() and PyString_AsString() accept Unicode objects.
3165
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003166- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003167 exists). INT_MAX and LONG_MAX will always be defined, even if
3168 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003169
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003170- PyFloat_FromString takes a second argument, pend, that was
3171 effectively useless. It is now officially useless but preserved for
3172 backwards compatibility. If the pend argument is not NULL, *pend is
3173 set to NULL.
3174
3175- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3176 for the attribute name. See note on getattr() above.
3177
3178- A few bug fixes to argument processing for Unicode.
3179 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3180 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3181 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003182 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003183
3184- Py_BuildValue accepts B format (for bgen-generated code).
3185
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003186
Jeremy Hylton1b618592000-09-26 05:32:36 +00003187Internals
3188
3189- On Unix, fix code for finding Python installation directory so that
3190 it works when argv[0] is a relative path.
3191
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003192- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003193 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003194 rather than by generating a copy of the object.
3195
Tim Peters482c0212000-09-26 06:33:09 +00003196- Several of the internal Unicode tables are much smaller now, and
3197 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003198
Jeremy Hylton97693b02000-09-26 17:42:51 +00003199- In the garbage collector: Fixed bug in collection of tuples. Fixed
3200 bug that caused some instances to be removed from the container set
3201 while they were still live. Fixed parsing in gc.set_debug() for
3202 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003203
3204- Fixed refcount problem in instance deallocation that only occurred
3205 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3206
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003207- On Windows, getpythonregpath is now protected against null data in
3208 registry key.
3209
3210- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003211 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003212
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003213
Jeremy Hylton1b618592000-09-26 05:32:36 +00003214Build and platform-specific issues
3215
3216- Better support of GNU Pth via --with-pth configure option.
3217
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003218- Python/C API now properly exposed to dynamically-loaded extension
3219 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003220
3221- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3222 Don't define MS_SYNC to be zero when it is undefined. Added missing
3223 prototypes in posixmodule.c.
3224
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003225- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003226 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003227
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003228- Fix largefile support on older NetBSD systems and OpenBSD by adding
3229 define for TELL64.
3230
3231
3232Tools and other miscellany
3233
3234- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3235
3236- freeze: The modulefinder now works with 2.0 opcodes.
3237
Tim Petersa3a3a032000-11-30 05:22:44 +00003238- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003239 Move hackery of sys.argv until after the Tk instance has been
3240 created, which allows the application-specific Tkinter
3241 initialization to be executed if present; also pass an explicit
3242 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003243
Jeremy Hylton1b618592000-09-26 05:32:36 +00003244
3245What's new in 2.0 beta 1?
3246=========================
3247
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003248Source Incompatibilities
3249------------------------
3250
3251None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3252such as single-argument append(), connect() and bind(), and changes to
3253str(long) and repr(float).
3254
3255
3256Binary Incompatibilities
3257------------------------
3258
3259- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3260with Python 2.0; these extensions will have to be rebuilt for Python
32612.0.
3262
3263- On Windows, attempting to import a third party extension built for
3264Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3265can do about this. Check your PYTHONPATH environment variable!
3266
3267- Python bytecode files (*.pyc and *.pyo) are not compatible between
3268releases.
3269
3270
3271Overview of Changes Since 1.6
3272-----------------------------
3273
3274There are many new modules (including brand new XML support through
3275the xml package, and i18n support through the gettext module); a list
3276of all new modules is included below. Lots of bugs have been fixed.
3277
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003278The process for making major new changes to the language has changed
3279since Python 1.6. Enhancements must now be documented by a Python
3280Enhancement Proposal (PEP) before they can be accepted.
3281
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003282There are several important syntax enhancements, described in more
3283detail below:
3284
3285 - Augmented assignment, e.g. x += 1
3286
3287 - List comprehensions, e.g. [x**2 for x in range(10)]
3288
3289 - Extended import statement, e.g. import Module as Name
3290
3291 - Extended print statement, e.g. print >> file, "Hello"
3292
3293Other important changes:
3294
3295 - Optional collection of cyclical garbage
3296
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003297Python Enhancement Proposal (PEP)
3298---------------------------------
3299
3300PEP stands for Python Enhancement Proposal. A PEP is a design
3301document providing information to the Python community, or describing
3302a new feature for Python. The PEP should provide a concise technical
3303specification of the feature and a rationale for the feature.
3304
3305We intend PEPs to be the primary mechanisms for proposing new
3306features, for collecting community input on an issue, and for
3307documenting the design decisions that have gone into Python. The PEP
3308author is responsible for building consensus within the community and
3309documenting dissenting opinions.
3310
3311The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003312
3313Augmented Assignment
3314--------------------
3315
3316This must have been the most-requested feature of the past years!
3317Eleven new assignment operators were added:
3318
Guido van Rossume905e952000-09-05 12:42:46 +00003319 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003320
3321For example,
3322
3323 A += B
3324
3325is similar to
3326
3327 A = A + B
3328
3329except that A is evaluated only once (relevant when A is something
3330like dict[index].attr).
3331
3332However, if A is a mutable object, A may be modified in place. Thus,
3333if A is a number or a string, A += B has the same effect as A = A+B
3334(except A is only evaluated once); but if a is a list, A += B has the
3335same effect as A.extend(B)!
3336
3337Classes and built-in object types can override the new operators in
3338order to implement the in-place behavior; the not-in-place behavior is
3339used automatically as a fallback when an object doesn't implement the
3340in-place behavior. For classes, the method name is derived from the
3341method name for the corresponding not-in-place operator by inserting
3342an 'i' in front of the name, e.g. __iadd__ implements in-place
3343__add__.
3344
3345Augmented assignment was implemented by Thomas Wouters.
3346
3347
3348List Comprehensions
3349-------------------
3350
3351This is a flexible new notation for lists whose elements are computed
3352from another list (or lists). The simplest form is:
3353
3354 [<expression> for <variable> in <sequence>]
3355
Guido van Rossum56db0952000-09-06 23:34:25 +00003356For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003357This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003358
3359You can also add a condition:
3360
3361 [<expression> for <variable> in <sequence> if <condition>]
3362
3363For example, [w for w in words if w == w.lower()] would yield the list
3364of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003365than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003366
3367You can also have nested for loops and more than one 'if' clause. For
3368example, here's a function that flattens a sequence of sequences::
3369
3370 def flatten(seq):
3371 return [x for subseq in seq for x in subseq]
3372
3373 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3374
3375This prints
3376
3377 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3378
3379List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003380Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003381
3382
3383Extended Import Statement
3384-------------------------
3385
3386Many people have asked for a way to import a module under a different
3387name. This can be accomplished like this:
3388
3389 import foo
3390 bar = foo
3391 del foo
3392
3393but this common idiom gets old quickly. A simple extension of the
3394import statement now allows this to be written as follows:
3395
3396 import foo as bar
3397
3398There's also a variant for 'from ... import':
3399
3400 from foo import bar as spam
3401
3402This also works with packages; e.g. you can write this:
3403
3404 import test.regrtest as regrtest
3405
3406Note that 'as' is not a new keyword -- it is recognized only in this
3407context (this is only possible because the syntax for the import
3408statement doesn't involve expressions).
3409
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003410Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003411
3412
3413Extended Print Statement
3414------------------------
3415
3416Easily the most controversial new feature, this extension to the print
3417statement adds an option to make the output go to a different file
3418than the default sys.stdout.
3419
3420For example, to write an error message to sys.stderr, you can now
3421write:
3422
3423 print >> sys.stderr, "Error: bad dog!"
3424
3425As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003426evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003427
3428 print >> None, "Hello world"
3429
3430is equivalent to
3431
3432 print "Hello world"
3433
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003434Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003435
3436
3437Optional Collection of Cyclical Garbage
3438---------------------------------------
3439
3440Python is now equipped with a garbage collector that can hunt down
3441cyclical references between Python objects. It's no replacement for
3442reference counting; in fact, it depends on the reference counts being
3443correct, and decides that a set of objects belong to a cycle if all
3444their reference counts can be accounted for from their references to
3445each other. This devious scheme was first proposed by Eric Tiedemann,
3446and brought to implementation by Neil Schemenauer.
3447
3448There's a module "gc" that lets you control some parameters of the
3449garbage collection. There's also an option to the configure script
3450that lets you enable or disable the garbage collection. In 2.0b1,
3451it's on by default, so that we (hopefully) can collect decent user
3452experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003453performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003454off by default in the final 2.0 release.
3455
3456
3457Smaller Changes
3458---------------
3459
3460A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3461map(None, seq1, seq2, ...) when the sequences have the same length;
3462i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3463the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003464zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003465
3466sys.version_info is a tuple (major, minor, micro, level, serial).
3467
3468Dictionaries have an odd new method, setdefault(key, default).
3469dict.setdefault(key, default) returns dict[key] if it exists; if not,
3470it sets dict[key] to default and returns that value. Thus:
3471
3472 dict.setdefault(key, []).append(item)
3473
3474does the same work as this common idiom:
3475
3476 if not dict.has_key(key):
3477 dict[key] = []
3478 dict[key].append(item)
3479
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003480There are two new variants of SyntaxError that are raised for
3481indentation-related errors: IndentationError and TabError.
3482
3483Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3484escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003485
3486The limits on the size of expressions and file in Python source code
3487have been raised from 2**16 to 2**32. Previous versions of Python
3488were limited because the maximum argument size the Python VM accepted
3489was 2**16. This limited the size of object constructor expressions,
3490e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3491limit was raised thanks to a patch by Charles Waldman that effectively
3492fixes the problem. It is now much more likely that you will be
3493limited by available memory than by an arbitrary limit in Python.
3494
3495The interpreter's maximum recursion depth can be modified by Python
3496programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3497limit is the maximum number of recursive calls that can be made by
3498Python code. The limit exists to prevent infinite recursion from
3499overflowing the C stack and causing a core dump. The default value is
35001000. The maximum safe value for a particular platform can be found
3501by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003502
3503New Modules and Packages
3504------------------------
3505
3506atexit - for registering functions to be called when Python exits.
3507
3508imputil - Greg Stein's alternative API for writing custom import
3509hooks.
3510
3511pyexpat - an interface to the Expat XML parser, contributed by Paul
3512Prescod.
3513
3514xml - a new package with XML support code organized (so far) in three
3515subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3516would fill a volume. There's a special feature whereby a
3517user-installed package named _xmlplus overrides the standard
3518xmlpackage; this is intended to give the XML SIG a hook to distribute
3519backwards-compatible updates to the standard xml package.
3520
3521webbrowser - a platform-independent API to launch a web browser.
3522
3523
Guido van Rossume905e952000-09-05 12:42:46 +00003524Changed Modules
3525---------------
3526
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003527array -- new methods for array objects: count, extend, index, pop, and
3528remove
3529
3530binascii -- new functions b2a_hex and a2b_hex that convert between
3531binary data and its hex representation
3532
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003533calendar -- Many new functions that support features including control
3534over which day of the week is the first day, returning strings instead
3535of printing them. Also new symbolic constants for days of week,
3536e.g. MONDAY, ..., SUNDAY.
3537
3538cgi -- FieldStorage objects have a getvalue method that works like a
3539dictionary's get method and returns the value attribute of the object.
3540
3541ConfigParser -- The parser object has new methods has_option,
3542remove_section, remove_option, set, and write. They allow the module
3543to be used for writing config files as well as reading them.
3544
3545ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003546optionally support the RFC 959 REST command.
3547
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003548gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003549
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003550httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3551the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003552
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003553locale -- implement getdefaultlocale for Win32 and Macintosh
3554
3555marshal -- no longer dumps core when marshaling deeply nested or
3556recursive data structures
3557
3558os -- new functions isatty, seteuid, setegid, setreuid, setregid
3559
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003560os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3561support under Unix.
3562
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003563os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003564
3565os.path -- fix semantics of os.path.commonprefix
3566
3567smtplib -- support for sending very long messages
3568
3569socket -- new function getfqdn()
3570
3571readline -- new functions to read, write and truncate history files.
3572The readline section of the library reference manual contains an
3573example.
3574
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003575select -- add interface to poll system call
3576
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003577shutil -- new copyfileobj function
3578
3579SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3580HTTP server.
3581
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003582Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003583
3584urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003585e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003586
3587whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003588
3589
3590Obsolete Modules
3591----------------
3592
3593None. However note that 1.6 made a whole slew of modules obsolete:
3594stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3595poly, zmod, strop, util, whatsound.
3596
3597
3598Changed, New, Obsolete Tools
3599----------------------------
3600
Tim Peters8b092332000-09-05 20:15:25 +00003601None.
Guido van Rossume905e952000-09-05 12:42:46 +00003602
3603
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003604C-level Changes
3605---------------
3606
3607Several cleanup jobs were carried out throughout the source code.
3608
3609All C code was converted to ANSI C; we got rid of all uses of the
3610Py_PROTO() macro, which makes the header files a lot more readable.
3611
3612Most of the portability hacks were moved to a new header file,
3613pyport.h; several other new header files were added and some old
3614header files were removed, in an attempt to create a more rational set
3615of header files. (Few of these ever need to be included explicitly;
3616they are all included by Python.h.)
3617
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003618Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003619and Win64, especially for the new Intel Itanium processor. Mick also
3620added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003621
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003622The C APIs to return an object's size have been update to consistently
3623use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3624previous versions, the abstract interfaces used PyXXX_Length and the
3625concrete interfaces used PyXXX_Size. The old names,
3626e.g. PyObject_Length, are still available for backwards compatibility
3627at the API level, but are deprecated.
3628
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003629The PyOS_CheckStack function has been implemented on Windows by
3630Fredrik Lundh. It prevents Python from failing with a stack overflow
3631on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003632
3633The GC changes resulted in creation of two new slots on object,
3634tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003635the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003636
3637The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003638C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003639
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003640PyErr_Format has been updated to automatically calculate the size of
3641the buffer needed to hold the formatted result string. This change
3642prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003643
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003644New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003645
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003646PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3647that are the same as their non-Ex counterparts except they take an
3648extra flag argument that tells them to close the file when done.
3649
3650XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003651
Tim Peters8b092332000-09-05 20:15:25 +00003652
3653Windows Changes
3654---------------
3655
3656New popen2/popen3/peopen4 in os module (see Changed Modules above).
3657
3658os.popen is much more usable on Windows 95 and 98. See Microsoft
3659Knowledge Base article Q150956. The Win9x workaround described there
3660is implemented by the new w9xpopen.exe helper in the root of your
3661Python installation. Note that Python uses this internally; it is not
3662a standalone program.
3663
3664Administrator privileges are no longer required to install Python
3665on Windows NT or Windows 2000. If you have administrator privileges,
3666Python's registry info will be written under HKEY_LOCAL_MACHINE.
3667Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003668under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003669uses of Python, but will prevent some advanced uses from working
3670(for example, running a Python script as an NT service, or possibly
3671from CGI).
3672
3673[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3674installer; instead, it installs the needed Tcl/Tk files directly in the
3675Python directory. If you already have a Tcl/Tk installation, this
3676wastes some disk space (about 4 Megs) but avoids problems with
3677conflicting Tcl/Tk installations, and makes it much easier for Python
3678to ensure that Tcl/Tk can find all its files.
3679
3680[This was new in 1.6] The Windows installer now installs by default in
3681\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3682
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003683
3684Updates to the changes between 1.5.2 and 1.6
3685--------------------------------------------
3686
3687The 1.6 NEWS file can't be changed after the release is done, so here
3688is some late-breaking news:
3689
3690New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3691and changes to getlocale() and setlocale().
3692
3693The new module is now enabled per default.
3694
3695It is not true that the encodings codecs cannot be used for normal
3696strings: the string.encode() (which is also present on 8-bit strings
3697!) allows using them for 8-bit strings too, e.g. to convert files from
3698cp1252 (Windows) to latin-1 or vice-versa.
3699
3700Japanese codecs are available from Tamito KAJIYAMA:
3701http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3702
3703
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003704======================================================================