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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
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +00009- Encoding declarations (PEP 263, phase 1) have been implemented.
10
Tim Petersf47630f2002-08-01 02:34:51 +000011- list.sort() has a new implementation. While cross-platform results
12 may vary, and in data-dependent ways, this is much faster on many
13 kinds of partially ordered lists than the previous implementation,
14 and reported to be just as fast on randomly ordered lists on
15 several major platforms. This sort is also stable (if A==B and A
16 precedes B in the list at the start, A precedes B after the sort too),
17 although the language definition does not guarantee stability. A
18 potential drawback is that list.sort() may require temp space of
19 len(list)*2 bytes (*4 on a 64-bit machine). It's therefore possible
20 for list.sort() to raise MemoryError now, even if a comparison function
21 does not. See <http://www.python.org/sf/587076> for full details.
22
Guido van Rossum2d5389c2002-07-23 03:44:35 +000023- All standard iterators now ensure that, once StopIteration has been
24 raised, all future calls to next() on the same iterator will also
25 raise StopIteration. There used to be various counterexamples to
26 this behavior, which could caused confusion or subtle program
27 breakage, without any benefits. (Note that this is still an
28 iterator's responsibility; the iterator framework does not enforce
29 this.)
30
Mark Hammondc0e35152002-07-16 01:32:30 +000031- Ctrl+C handling on Windows has been made more consistent with
32 other platforms. KeyboardInterrupt can now reliably be caught,
Tim Petersf47630f2002-08-01 02:34:51 +000033 and Ctrl+C at an interative prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +000034 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Petersf47630f2002-08-01 02:34:51 +000035 interrupt time.sleep() in the main thread, and any child processes
36 created via the popen family are also interrupted (as generally
Mark Hammondc0e35152002-07-16 01:32:30 +000037 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
38
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000039- Slices and repetitions of buffer objects now consistently return
40 a string. Formerly, strings would be returned most of the time,
41 but a buffer object would be returned when the repetition count
42 was one or when the slice range was all inclusive.
43
Guido van Rossumc7c36502002-06-21 01:29:25 +000044- The __slots__ variable can now mention "private" names, and the
45 right thing will happen (e.g. __slots__ = ["__foo"]).
46
Walter Dörwald3430d702002-06-17 10:43:59 +000047- Unicode objects in sys.path are no longer ignored but treated
48 as directory names.
49
Guido van Rossum9562bcf2002-06-14 21:31:18 +000050- The built-ins slice() and buffer() are now callable types. The
51 types classobj (formerly class), code, function, instance, and
52 instancemethod (formerly instance-method), which have no built-in
53 names but are accessible through the types module, are now also
54 callable. The type dict-proxy is renamed to dictproxy.
55
Neal Norwitz1f68fc72002-06-14 00:50:42 +000056- Fixed string.startswith and string.endswith builtin methods
57 so they accept negative indices. [SF bug 493951]
58
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000059- Fixed a bug with a continue inside a try block and a yield in the
60 finally clause. [SF bug 567538]
61
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000062- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000063 with a third "stride" parameter. For example, "hello world"[::-1]
64 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000065
Guido van Rossum9f7549b2002-06-10 21:39:42 +000066- Cycles going through the __class__ link of a new-style instance are
67 now detected by the garbage collector.
68
Guido van Rossum9923ffe2002-06-04 19:52:53 +000069- Classes using __slots__ are now properly garbage collected.
70 [SF bug 519621]
71
72- Tightened the __slots__ rules: a slot name must be a valid Python
73 identifier.
74
Guido van Rossum2e4e0262002-06-04 05:58:34 +000075- The constructor for the module type now requires a name argument and
76 takes an optional docstring argument. Previously, this constructor
77 ignored its arguments. As a consequence, deriving a class from a
78 module (not from the module type) is now illegal; previously this
79 created an unnamed module, just like invoking the module type did.
80 [SF bug 563060]
81
Neal Norwitzd68f5172002-05-29 15:54:55 +000082- A new warning PendingDeprecationWarning was added to provide
83 direction on features which are in the process of being deprecated.
84 The warning will not be printed by default. To see the pending
85 deprecations, use -Walways::PendingDeprecationWarning::
86 as a command line option or warnings.filterwarnings() in code.
87
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000088- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000089 for 'str' and 'unicode', and can be used instead of
90 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000091 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000092 is an abstract base class and cannot be instantiated directly.
93
Fred Draked0ba6362002-05-02 21:28:26 +000094- Deprecated features of xrange objects have been removed as
95 promised. The start, stop, and step attributes and the tolist()
96 method no longer exist. xrange repetition and slicing have been
97 removed.
98
Guido van Rossum7dab2422002-04-26 19:40:56 +000099- New builtin function enumerate(x), from PEP 279. Example:
100 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
101 The argument can be an arbitrary iterable object.
102
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000103- The assert statement no longer tests __debug__ at runtime. This means
104 that assert statements cannot be disabled by assigning a false value
105 to __debug__.
106
Walter Dörwald068325e2002-04-15 13:36:47 +0000107- A method zfill() was added to str and unicode, that fills a numeric
108 string to the left with zeros. For example,
109 "+123".zfill(6) -> "+00123".
110
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000111- Complex numbers supported divmod() and the // and % operators, but
112 these make no sense. Since this was documented, they're being
113 deprecated now.
114
Guido van Rossum26dd8302002-04-26 20:11:29 +0000115- String and unicode methods lstrip(), rstrip() and strip() now take
116 an optional argument that specifies the characters to strip. For
117 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000118
Guido van Rossumc69343b2002-04-12 19:22:48 +0000119- Added a new dict method pop(key). This removes and returns the
120 value corresponding to key. [SF patch #539949]
121
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000122- Changed new-style class instantiation so that when C's __new__
123 method returns something that's not a C instance, its __init__ is
124 not called. [SF bug #537450]
125
Guido van Rossum181e41a2002-04-06 00:23:25 +0000126- Fixed super() to work correctly with class methods. [SF bug #535444]
127
Guido van Rossum47834462002-04-04 15:21:33 +0000128- A new built-in type, bool, has been added, as well as built-in
129 names for its two values, True and False. Comparisons and sundry
130 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000131 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000132 is backward compatible.
133
Guido van Rossum95b62a62002-03-29 01:07:24 +0000134- Fixed two bugs reported as SF #535905: under certain conditions,
135 deallocating a deeply nested structure could cause a segfault in the
136 garbage collector, due to interaction with the "trashcan" code;
137 access to the current frame during destruction of a local variable
138 could access a pointer to freed memory.
139
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000140- The optional object allocator ("pymalloc") has been enabled by
141 default. The recommended practice for memory allocation and
142 deallocation has been streamlined. A header file is included,
143 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
144 and lets them use the same API with Python versions from 1.5.2
145 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000146
Guido van Rossum8c842552002-03-14 23:05:54 +0000147- If you try to pickle an instance of a class that has __slots__ but
148 doesn't define or override __getstate__, a TypeError is now raised.
149 This is done by adding a bozo __getstate__ to the class that always
150 raises TypeError. (Before, this would appear to be pickled, but the
151 state of the slots would be lost.)
152
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000153- PyErr_Display will provide file and line information for all exceptions
154 that have an attribute print_file_and_line, not just SyntaxErrors.
155
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000156- The UTF-8 codec will now encode and decode Unicode surrogates
157 correctly and without raising exceptions for unpaired ones.
158
Neal Norwitz649b7592002-01-01 19:07:13 +0000159- file.xreadlines() now raises a ValueError if the file is closed:
160 Previously, an xreadlines object was returned which would raise
161 a ValueError when the xreadlines.next() method was called.
162
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000163- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000164 An exception will now be raised if more than one argument is used.
165
Tim Petersaf8446f2001-12-21 21:36:50 +0000166Extension modules
167
Guido van Rossum79f0a102002-07-23 03:32:08 +0000168- The strptime function in the time module is now always available (a
169 Python implementation is used when the C library doesn't define it).
170
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000171- The 'new' module is no longer an extension, but a Python module that
172 only exists for backwards compatibility. Its contents are no longer
173 functions but callable type objects.
174
Tim Peters81b92512002-04-29 01:37:32 +0000175- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000176 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000177 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000178
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000179- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
180 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000181
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000182- The locale module now exposes the C library's gettext interface.
183
Tim Petersfbf74f22002-03-14 19:06:01 +0000184- A security hole ("double free") was found in zlib-1.1.3, a popular
185 third party compression library used by some Python modules. The
186 hole was quickly plugged in zlib-1.1.4, and the Windows build of
187 Python now ships with zlib-1.1.4.
188
Martin v. Löwis688357e2002-04-08 21:28:20 +0000189- pwd, grp, and resource return enhanced tuples now, with symbolic
190 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000191
Martin v. Löwis99866332002-03-01 10:27:01 +0000192- array.array is now a type object. A new format character
193 'u' indicates Py_UNICODE arrays. For those, .tounicode and
194 .fromunicode methods are available. Arrays now support __iadd__
195 and __imul__.
196
Neal Norwitze790eae2002-01-01 21:14:12 +0000197- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000198 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
199 is called.
200
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000201- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
202 been added where available.
203
Tim Petersaf8446f2001-12-21 21:36:50 +0000204Library
205
Guido van Rossum4a57c332002-08-02 18:05:20 +0000206- New "algorithms" module: heapq, implements a heap queue. Thanks to
207 Kevin O'Connor for the code and François Pinard for an entertaining
208 write-up explaining the theory and practical uses of heaps.
209
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000210- New encoding for the Palm OS character set: palmos.
211
Tim Peters943382c2002-07-07 03:59:34 +0000212- binascii.crc32() and the zipfile module had problems on some 64-bit
213 platforms. These have been fixed. On a platform with 8-byte C longs,
214 crc32() now returns a signed-extended 4-byte result, so that its value
215 as a Python int is equal to the value computed a 32-bit platform.
216
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000217- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
218 argument.
219
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000220- Some fixes in the copy module: when an object is copied through its
221 __reduce__ method, there was no check for a __setstate__ method on
222 the result [SF patch 565085]; deepcopy should treat instances of
223 custom metaclasses the same way it treats instances of type 'type'
224 [SF patch 560794].
225
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000226- Sockets now support timeout mode. After s.settimeout(T), where T is
227 a float expressing seconds, subsequent operations raise an exception
228 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000229 mode, use s.settimeout(None). There's also a module function,
230 socket.setdefaulttimeout(T), which sets the default for all sockets
231 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000232
233- getopt.gnu_getopt was added. This supports GNU-style option
234 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000235
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000236- Stop using strings for exceptions. String objects used for
237 exceptions are now classes deriving from Exception. The objects
238 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
239 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000240
Walter Dörwald474458d2002-06-04 15:16:29 +0000241- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
242 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
243 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
244 big endian systems were added to the codecs module. The old names
245 BOM32_* and BOM64_* were off by a factor of 2.
246
Guido van Rossumf9257822002-06-18 20:43:18 +0000247- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000248
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000249- ftplib.retrlines() now tests for callback is None rather than testing
250 for False. Was causing an error when given a callback object which
251 was callable but also returned len() as zero. The change may
252 create new breakage if the caller relied on the undocumented behavior
253 and called with callback set to [] or some other False value not
254 identical to None.
255
Tim Peters46c04e12002-05-05 20:40:00 +0000256- random.gauss() uses a piece of hidden state used by nothing else,
257 and the .seed() and .whseed() methods failed to reset it. In other
258 words, setting the seed didn't completely determine the sequence of
259 results produced by random.gauss(). It does now. Programs repeatedly
260 mixing calls to a seed method with calls to gauss() may see different
261 results now.
262
Fred Drake7f781c92002-05-01 20:33:53 +0000263- The pickle.Pickler class grew a clear_memo() method to mimic that
264 provided by cPickle.Pickler.
265
Tim Peters81b92512002-04-29 01:37:32 +0000266- difflib's SequenceMatcher class now does a dynamic analysis of
267 which elements are so frequent as to constitute noise. For
268 comparing files as sequences of lines, this generally works better
269 than the IS_LINE_JUNK function, and function ndiff's linejunk
270 argument defaults to None now as a result. A happy benefit is
271 that SequenceMatcher may run much faster now when applied
272 to large files with many duplicate lines (for example, C program
273 text with lots of repeated "}" and "return NULL;" lines).
274
Guido van Rossum256705b2002-04-23 13:29:43 +0000275- New Text.dump() method in Tkinter module.
276
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000277- New distutils commands for building packagers were added to
278 support pkgtool on Solaris and swinstall on HP-UX.
279
280- distutils now has a new abstract binary packager base class
281 command/bdist_packager, which simplifies writing packagers.
282 This will hopefully provide the missing bits to encourage
283 people to submit more packagers, e.g. for Debian, FreeBSD
284 and other systems.
285
Guido van Rossumf9257822002-06-18 20:43:18 +0000286- The UTF-16, -LE and -BE stream readers now raise a
287 NotImplementedError for all calls to .readline(). Previously, they
288 used to just produce garbage or fail with an encoding error --
289 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 +0000290 work well with these.
291
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000292- compileall now supports quiet operation.
293
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000294- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000295 connections.
296
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000297- socket module: the SSL support was broken out of the main
298 _socket module C helper and placed into a new _ssl helper
299 which now gets imported by socket.py if available and working.
300
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000301- encodings package: added aliases for all supported IANA character
302 sets
303
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000304- ftplib: to safeguard the user's privacy, anonymous login will use
305 "anonymous@" as default password, rather than the real user and host
306 name.
307
Fred Drake36736122002-01-10 13:50:31 +0000308- webbrowser: tightened up the command passed to os.system() so that
309 arbitrary shell code can't be executed because a bogus URL was
310 passed in.
311
Tim Peters11bd9942002-02-01 00:52:29 +0000312- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000313 gettext.find an optional all argument. Translations will now fallback
314 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000315
Martin v. Löwis9668b932002-01-12 11:27:42 +0000316- distutils bdist commands now offer a --skip-build option.
317
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000318- warnings.warn now accepts a Warning instance as first argument.
319
Fred Drakefed7e852002-04-04 19:36:15 +0000320- The xml.sax.expatreader.ExpatParser class will no longer create
321 circular references by using itself as the locator that gets passed
322 to the content handler implementation. [SF bug #535474]
323
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000324- The email.Parser.Parser class now properly parses strings regardless
325 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
326 or CRLF). Also, the Header class's constructor default arguments
327 has changed slightly so that an explicit maxlinelen value is always
328 honored.
329
Tim Petersaf8446f2001-12-21 21:36:50 +0000330Tools/Demos
331
Marc-André Lemburg46260092002-04-04 16:17:11 +0000332- freeze.py now produces binaries which can import shared modules,
333 unlike before when this failed due to missing symbol exports in
334 the generated binary.
335
Tim Petersaf8446f2001-12-21 21:36:50 +0000336Build
337
Tim Petersf47630f2002-08-01 02:34:51 +0000338- The public Python C API will generally be declared using PyAPI_FUNC
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000339 and PyAPI_DATA macros, while Python extension module init functions
340 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
341 are deprecated.
342
Tim Petersc6a3ff62002-07-08 22:11:52 +0000343- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
344 get into infinite loops, when a new-style class got garbage-collected.
345 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
346 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
347 COUNT_ALLOCS is not enabled by default, in either release or debug
348 builds, and that new-style classes are immortal only in COUNT_ALLOCS
349 builds.
350
Tim Peters943382c2002-07-07 03:59:34 +0000351- Compiling out the cyclic garbage collector is no longer an option.
352 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
353 that it's always defined (for the benefit of any extension modules
354 that may be conditionalizing on it). A bonus is that any extension
355 type participating in cyclic gc can choose to participate in the
356 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
357 to require editing the core to teach the trashcan mechanism about the
358 new type.
359
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000360- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000361
362 The Standard C macro HUGE_VAL and its float and long double analogs,
363 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
364 positive infinities.
365
366 Python only uses the double HUGE_VAL, and only to #define its own symbol
367 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
368 pyport.h used to try to worm around that, but the workarounds triggered
369 other bugs on other platforms, so we gave up. If your platform defines
370 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
371 that works on your platform. The only instance of this I'm sure about
372 is on an unknown subset of Cray systems, described here:
373
374 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
375
376 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
377
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000378- The configure option --without-doc-strings can be used to remove the
379 doc strings from the builtin functions and modules; this reduces the
380 size of the executable.
381
Tim Peters639295f2002-04-21 07:30:30 +0000382- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
383 say how or when to configure it, or how to turn it off.
384
Martin v. Löwis1142de32002-03-29 16:28:31 +0000385- On Unix, a shared libpython2.3.so can be created with --enable-shared.
386
Tim Peters8deda702002-03-30 10:06:07 +0000387- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
388 preprocessor symbols were eliminated. The internal decisions they
389 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000390
Fred Drake7d28b732002-05-02 21:17:00 +0000391- The tools used to build the documentation now work under Cygwin as
392 well as Unix.
393
Skip Montanaro57454e52002-06-14 20:30:31 +0000394- The bsddb and dbm module builds have been changed to try and avoid version
395 skew problems and disable linkage with Berkeley DB 1.85 unless the
396 installer knows what s/he's doing. See the section on building these
397 modules in the README file for details.
398
Tim Petersaf8446f2001-12-21 21:36:50 +0000399C API
400
Thomas Heller085358a2002-07-29 14:27:41 +0000401- New functions PyErr_SetExcFromWindowsErr() and
402 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
403 PyErr_SetFromWindowsErrWithFilename() and
404 PyErr_SetFromWindowsErr(), but they allow to specify
405 the exception type to raise. Available on Windows.
406
Tim Peters7c321a82002-07-09 02:57:01 +0000407- Py_FatalError() is now declared as taking a const char* argument. It
408 was previously declared without const. This should not affect working
409 code.
410
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000411- Added new macro PySequence_ITEM(o, i) that directly calls
412 sq_item without rechecking that o is a sequence and without
413 adjusting for negative indices.
414
Fred Draked0ba6362002-05-02 21:28:26 +0000415- PyRange_New() now raises ValueError if the fourth argument is not 1.
416 This is part of the removal of deprecated features of the xrange
417 object.
418
Guido van Rossum517c7d42002-04-26 02:49:14 +0000419- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
420 coercion if both arguments have the same type but this type has the
421 CHECKTYPES flag set. This is to better support proxies.
422
Neil Schemenauer9344b142002-04-12 23:00:08 +0000423- The type of tp_free has been changed from "void (*)(PyObject *)" to
424 "void (*)(void *)".
425
426- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
427
Guido van Rossum0986d822002-04-08 01:38:42 +0000428- A type can now inherit its metatype from its base type. Previously,
429 when PyType_Ready() was called, if ob_type was found to be NULL, it
430 was always set to &PyType_Type; now it is set to base->ob_type,
431 where base is tp_base, defaulting to &PyObject_Type.
432
433- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
434
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000435- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000436
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000437- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000438 without going through the buffer API.
439
Martin v. Löwis7198a522002-01-01 19:59:11 +0000440- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
441
Tim Peters10a3bb52001-12-25 19:07:38 +0000442- An old #define of ANY as void has been removed from pyport.h. This
443 hasn't been used since Python's pre-ANSI days, and the #define has
444 been marked as obsolete since then. SF bug 495548 says it created
445 conflicts with other packages, so keeping it around wasn't harmless.
446
Tim Petersaf8446f2001-12-21 21:36:50 +0000447- Because Python's magic number scheme broke on January 1st, we decided
448 to stop Python development. Thanks for all the fish!
449
Tim Petersfb05db22002-03-11 00:24:00 +0000450- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000451 scheme to a new one. See Python/import.c for details.
452
Tim Petersaf8446f2001-12-21 21:36:50 +0000453New platforms
454
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000455- AtheOS is now supported.
456
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000457- the EMX runtime environment on OS/2 is now supported.
458
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000459- GNU/Hurd is now supported.
460
Tim Petersaf8446f2001-12-21 21:36:50 +0000461Tests
462
463Windows
464
Tim Peters08e72952002-04-16 20:48:01 +0000465- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
466 of that has been fixed in the installer (disabled Wise's "delete in-
467 use files" uninstall option).
468
Guido van Rossum181e41a2002-04-06 00:23:25 +0000469- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
470
Tim Peters33187922002-04-04 20:02:04 +0000471- The installer now installs Start menu shortcuts under (the local
472 equivalent of) "All Users" when doing an Admin install.
473
Tim Petersfb05db22002-03-11 00:24:00 +0000474- file.truncate([newsize]) now works on Windows for all newsize values.
475 It used to fail if newsize didn't fit in 32 bits, reflecting a
476 limitation of MS _chsize (which is no longer used).
477
Tim Petersab034fa2002-02-01 11:27:43 +0000478- os.waitpid() is now implemented for Windows, and can be used to block
479 until a specified process exits. This is similar to, but not exactly
480 the same as, os.waitpid() on POSIX systems. If you're waiting for
481 a specific process whose pid was obtained from one of the spawn()
482 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000483 See the docs for details. The docs were changed to clarify that
484 spawn functions return, and waitpid requires, a process handle on
485 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000486
Tim Peters11bd9942002-02-01 00:52:29 +0000487- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000488 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000489 to a nasty problem: before 2.3, if you got a temp file on Windows, it
490 got wrapped in an object whose close() method first closed the
491 underlying file, then deleted the file. This usually worked fine.
492 However, the spawn family of functions on Windows create (at a low C
493 level) the same set of open files in the spawned process Q as were
494 open in the spawning process P. If a temp file f was among them, then
495 doing f.close() in P first closed P's C-level file handle on f, but Q's
496 C-level file handle on f remained open, so the attempt in P to delete f
497 blew up with a "Permission denied" error (Windows doesn't allow
498 deleting open files). This was surprising, subtle, and difficult to
499 work around.
500
501- The os module now exports all the symbolic constants usable with the
502 low-level os.open() on Windows: the new constants in 2.3 are
503 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
504 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
505 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
506 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
507 (so specify both if you want both; note that neither is useful unless
508 specified with O_CREAT too).
509
Tim Petersaf8446f2001-12-21 21:36:50 +0000510Mac
511
512
Tim Peters909c0912001-12-14 23:16:18 +0000513What's New in Python 2.2 final?
514Release date: 21-Dec-2001
515===============================
516
517Type/class unification and new-style classes
518
Barry Warsaw52acb492001-12-21 20:04:22 +0000519- pickle.py, cPickle: allow pickling instances of new-style classes
520 with a custom metaclass.
521
Tim Peters909c0912001-12-14 23:16:18 +0000522Core and builtins
523
Barry Warsaw52acb492001-12-21 20:04:22 +0000524- weakref proxy object: when comparing, unwrap both arguments if both
525 are proxies.
526
Tim Peters909c0912001-12-14 23:16:18 +0000527Extension modules
528
Barry Warsaw52acb492001-12-21 20:04:22 +0000529- binascii.b2a_base64(): fix a potential buffer overrun when encoding
530 very short strings.
531
532- cPickle: the obscure "fast" mode was suspected of causing stack
533 overflows on the Mac. Hopefully fixed this by setting the recursion
534 limit much smaller. If the limit is too low (it only affects
535 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
536 when compiling cPickle.c (or in pyconfig.h).
537
Tim Peters909c0912001-12-14 23:16:18 +0000538Library
539
Barry Warsaw52acb492001-12-21 20:04:22 +0000540- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
541 close or delete time).
542
543- rfc822.py: fixed a bug where the address '<>' was converted to None
544 instead of an empty string (also fixes the email.Utils module).
545
546- xmlrpclib.py: version 1.0.0; uses precision for doubles.
547
548- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000549 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000550
Tim Peters909c0912001-12-14 23:16:18 +0000551Tools/Demos
552
553Build
554
555C API
556
557New platforms
558
559Tests
560
561Windows
562
Barry Warsaw52acb492001-12-21 20:04:22 +0000563- distutils package: fixed broken Windows installers (bdist_wininst).
564
565- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
566 instances are deleted at process exit time.
567
568- socket.py: prevent mysterious warnings when socket instances are
569 deleted at process exit time.
570
571- posixmodule.c: fix a Windows crash with stat() of a filename ending
572 in backslash.
573
Tim Peters909c0912001-12-14 23:16:18 +0000574Mac
575
Barry Warsaw52acb492001-12-21 20:04:22 +0000576- The Carbon toolbox modules have been upgraded to Universal Headers
577 3.4, and experimental CoreGraphics and CarbonEvents modules have
578 been added. All only for framework-enabled MacOSX.
579
Tim Peters909c0912001-12-14 23:16:18 +0000580
Tim Peters6272dfd2001-12-13 19:34:00 +0000581What's New in Python 2.2c1?
582Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000583===========================
584
585Type/class unification and new-style classes
586
Barry Warsaw06557452001-12-14 20:47:12 +0000587- Guido's tutorial introduction to the new type/class features has
588 been extensively updated. See
589
590 http://www.python.org/2.2/descrintro.html
591
592 That remains the primary documentation in this area.
593
Guido van Rossum33bab012001-12-05 22:45:48 +0000594- Fixed a leak: instance variables declared with __slots__ were never
595 deleted!
596
Guido van Rossum4b800852001-12-03 00:54:52 +0000597- The "delete attribute" method of descriptor objects is called
598 __delete__, not __del__. In previous releases, it was mistakenly
599 called __del__, which created an unfortunate overloading condition
600 with finalizers. (The "get attribute" and "set attribute" methods
601 are still called __get__ and __set__, respectively.)
602
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000603- Some subtle issues with the super built-in were fixed:
604
605 (a) When super itself is subclassed, its __get__ method would still
606 return an instance of the base class (i.e., of super).
607
608 (b) super(C, C()).__class__ would return C rather than super. This
609 is confusing. To fix this, I decided to change the semantics of
610 super so that it only applies to code attributes, not to data
611 attributes. After all, overriding data attributes is not
612 supported anyway.
613
614 (c) The __get__ method didn't check whether the argument was an
615 instance of the type used in creation of the super instance.
616
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000617- Previously, hash() of an instance of a subclass of a mutable type
618 (list or dictionary) would return some value, rather than raising
619 TypeError. This has been fixed. Also, directly calling
620 dict.__hash__ and list.__hash__ now raises the same TypeError
621 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000622
Guido van Rossumd331cb52001-12-05 19:46:42 +0000623- New-style objects now support deleting their __dict__. This is for
624 all intents and purposes equivalent to assigning a brand new empty
625 dictionary, but saves space if the object is not used further.
626
Tim Petersb3c9af12001-11-17 00:21:57 +0000627Core and builtins
628
Tim Peters3caca232001-12-06 06:23:26 +0000629- -Qnew now works as documented in PEP 238: when -Qnew is passed on
630 the command line, all occurrences of "/" use true division instead
631 of classic division. See the PEP for details. Note that "all"
632 means all instances in library and 3rd-party modules, as well as in
633 your own code. As the PEP says, -Qnew is intended for use only in
634 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000635 Note that test_coercion.py in the standard Python test suite fails
636 under -Qnew; this is expected, and won't be repaired until true
637 division becomes the default (in the meantime, test_coercion is
638 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000639
Fred Drake6c01e252001-12-14 17:08:12 +0000640- complex() now only allows the first argument to be a string
641 argument, and raises TypeError if either the second arg is a string
642 or if the second arg is specified when the first is a string.
643
Tim Petersb3c9af12001-11-17 00:21:57 +0000644Extension modules
645
Martin v. Löwis560da622001-11-24 09:24:51 +0000646- gc.get_referents was renamed to gc.get_referrers.
647
Tim Petersb3c9af12001-11-17 00:21:57 +0000648Library
649
Tim Peters25059d32001-12-07 20:35:43 +0000650- Functions in the os.spawn() family now release the global interpreter
651 lock around calling the platform spawn. They should always have done
652 this, but did not before 2.2c1. Multithreaded programs calling
653 an os.spawn function with P_WAIT will no longer block all Python threads
654 until the spawned program completes. It's possible that some programs
655 relies on blocking, although more likely by accident than by design.
656
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000657- webbrowser defaults to netscape.exe on OS/2 now.
658
Martin v. Löwis652e1912001-11-25 14:50:56 +0000659- Tix.ResizeHandle exposes detach_widget, hide, and show.
660
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000661- The charset alias windows_1252 has been added.
662
Barry Warsaw06557452001-12-14 20:47:12 +0000663- types.StringTypes is a tuple containing the defined string types;
664 usually this will be (str, unicode), but if Python was compiled
665 without Unicode support it will be just (str,).
666
667- The pulldom and minidom modules were synchronized to PyXML.
668
Tim Petersb3c9af12001-11-17 00:21:57 +0000669Tools/Demos
670
Barry Warsaw06557452001-12-14 20:47:12 +0000671- A new script called Tools/scripts/google.py was added, which fires
672 off a search on Google.
673
Tim Petersb3c9af12001-11-17 00:21:57 +0000674Build
675
Barry Warsaw06557452001-12-14 20:47:12 +0000676- Note that release builds of Python should arrange to define the
677 preprocessor symbol NDEBUG on the command line (or equivalent).
678 In the 2.2 pre-release series we tried to define this by magic in
679 Python.h instead, but it proved to cause problems for extension
680 authors. The Unix, Windows and Mac builds now all define NDEBUG in
681 release builds via cmdline (or equivalent) instead. Ports to
682 other platforms should do likewise.
683
Jack Jansen1999ef42001-12-06 21:47:20 +0000684- It is no longer necessary to use --with-suffix when building on a
685 case-insensitive file system (such as Mac OS X HFS+). In the build
686 directory an extension is used, but not in the installed python.
687
Tim Petersb3c9af12001-11-17 00:21:57 +0000688C API
689
Tim Petersf582b822001-12-11 18:51:08 +0000690- New function PyDict_MergeFromSeq2() exposes the builtin dict
691 constructor's logic for updating a dictionary from an iterable object
692 producing key-value pairs.
693
Tim Peterscffed4b2001-11-29 03:26:37 +0000694- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000695 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000696 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
697 dump core in some bad cases. This has been repaired. As a result,
698 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
699 previously went unchallenged.
700
Tim Petersb3c9af12001-11-17 00:21:57 +0000701New platforms
702
703Tests
704
705Windows
706
707Mac
708
Jack Jansenffa260f2001-12-06 21:14:00 +0000709- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
710 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000711
Barry Warsaw06557452001-12-14 20:47:12 +0000712- Changed logic for finding python home in Mac OS X framework Pythons.
713 Now sys.executable points to the executable again, in stead of to
714 the shared library. The latter is used only for locating the python
715 home.
716
717
Tim Peters84362bc2001-10-19 17:55:30 +0000718What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000719Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000720===========================
721
722Type/class unification and new-style classes
723
Guido van Rossum3d27df02001-11-15 20:27:54 +0000724- Multiple inheritance mixing new-style and classic classes in the
725 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000726
727 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000728 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000729
730 The MRO (method resolution order) for each base class is respected
731 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000732 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000733 This needs to be documented.
734
Tim Petersa427a2b2001-10-29 22:25:45 +0000735- The new builtin dictionary() constructor, and dictionary type, have
736 been renamed to dict. This reflects a decade of common usage.
737
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000738- dict() now accepts an iterable object producing 2-sequences. For
739 example, dict(d.items()) == d for any dictionary d. The argument,
740 and the elements of the argument, can be any iterable objects.
741
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000742- New-style classes can now have a __del__ method, which is called
743 when the instance is deleted (just like for classic classes).
744
Guido van Rossum12d955c2001-10-26 14:56:06 +0000745- Assignment to object.__dict__ is now possible, for objects that are
746 instances of new-style classes that have a __dict__ (unless the base
747 class forbids it).
748
Guido van Rossumc8e56452001-10-22 00:43:43 +0000749- Methods of built-in types now properly check for keyword arguments
750 (formerly these were silently ignored). The only built-in methods
751 that take keyword arguments are __call__, __init__ and __new__.
752
Guido van Rossum86443212001-10-27 22:28:54 +0000753- The socket function has been converted to a type; see below.
754
Tim Peters84362bc2001-10-19 17:55:30 +0000755Core and builtins
756
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000757- Assignment to __debug__ raises SyntaxError at compile-time. This
758 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000759 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000760
Guido van Rossum12d955c2001-10-26 14:56:06 +0000761- Clarified the error messages for unsupported operands to an operator
762 (like 1 + '').
763
Tim Peters84362bc2001-10-19 17:55:30 +0000764Extension modules
765
Tim Peters5ebfd362001-11-13 23:11:19 +0000766- mmap has a new keyword argument, "access", allowing a uniform way for
767 both Windows and Unix users to create read-only, write-through and
768 copy-on-write memory mappings. This was previously possible only on
769 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000770 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000771 platforms. Thanks to Jay T Miller for repairing this!
772
Tim Peters169ded02001-11-03 19:57:21 +0000773- By default, the gc.garbage list now contains only those instances in
774 unreachable cycles that have __del__ methods; in 2.1 it contained all
775 instances in unreachable cycles. "Instances" here has been generalized
776 to include instances of both new-style and old-style classes.
777
Guido van Rossum12d955c2001-10-26 14:56:06 +0000778- The socket module defines a new method for socket objects,
779 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000780 send() until all data has been sent. Also, the socket function has
781 been converted to a subclassable type, like list and tuple (etc.)
782 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000783
784- Various bugfixes to the curses module. There is now a test suite
785 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000786
Guido van Rossum692adf12001-10-30 03:03:03 +0000787- binascii.b2a_base64 no longer places an arbitrary restriction of 57
788 bytes on its input.
789
Tim Peters84362bc2001-10-19 17:55:30 +0000790Library
791
Tim Peters5ebfd362001-11-13 23:11:19 +0000792- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000793 convenience function.
794
Tim Peters75335872001-11-03 19:35:43 +0000795- Symbolic group names in regular expressions must be unique. For
796 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
797 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000798 Python 2.2 detects this error at regexp compilation time;
799 previously, the error went undetected, and results were
800 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
801 pattern.subn() methods have been rewritten in C. Also, an
802 experimental function/method finditer() has been added, which works
803 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000804
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000805- Tix exposes more commands through the classes DirSelectBox,
806 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
807 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
808 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
809
Tim Peters98791af2001-10-23 01:59:54 +0000810- Traceback objects are now scanned by cyclic garbage collection, so
811 cycles created by casual use of sys.exc_info() no longer cause
812 permanent memory leaks (provided garbage collection is enabled).
813
Guido van Rossum49192142001-10-24 20:51:44 +0000814- os.extsep -- a new variable needed by the RISCOS support. It is the
815 separator used by extensions, and is '.' on all platforms except
816 RISCOS, where it is '/'. There is no need to use this variable
817 unless you have a masochistic desire to port your code to RISCOS.
818
Barry Warsaw012852b2001-11-16 16:17:27 +0000819- mimetypes.py has optional support for non-standard, but commonly
820 found types. guess_type() and guess_extension() now accept an
821 optional `strict' flag, defaulting to true, which controls whether
822 recognize non-standard types or not. A few non-standard types we
823 know about have been added. Also, when run as a script, there are
824 new -l and -e options.
825
826- statcache is now deprecated.
827
828- email.Utils.formatdate() now produces the preferred RFC 2822 style
829 dates with numeric timezones (it used to produce obsolete dates
830 hard coded to "GMT" timezone). An optional `localtime' flag is
831 added to produce dates in the local timezone, with daylight savings
832 time properly taken into account.
833
834- In pickle and cPickle, instead of masking errors in load() by
835 transforming them into SystemError, we let the original exception
836 propagate out. Also, implement support for __safe_for_unpickling__
837 in pickle, as it already was supported in cPickle.
838
Tim Peters84362bc2001-10-19 17:55:30 +0000839Tools/Demos
840
841Build
842
Barry Warsaw012852b2001-11-16 16:17:27 +0000843- The dbm module is built using libdb1 if available. The bsddb module
844 is built with libdb3 if available.
845
846- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
847
Tim Peters84362bc2001-10-19 17:55:30 +0000848C API
849
Tim Peters1fc240e2001-10-26 05:06:50 +0000850- New function PySequence_Fast_GET_SIZE() returns the size of a non-
851 NULL result from PySequence_Fast(), more quickly than calling
852 PySequence_Size().
853
Barry Warsaw012852b2001-11-16 16:17:27 +0000854- New argument unpacking function PyArg_UnpackTuple() added.
855
856- New functions PyObject_CallFunctionObjArgs() and
857 PyObject_CallMethodObjArgs() have been added to make it more
858 convenient and efficient to call functions and methods from C.
859
860- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
861 possible that this will propagate errors it didn't before.
862
863- New function PyObject_CheckReadBuffer(), which returns true if its
864 argument supports the single-segment readable buffer interface.
865
Tim Peters84362bc2001-10-19 17:55:30 +0000866New platforms
867
Guido van Rossum86443212001-10-27 22:28:54 +0000868- We've finally confirmed that this release builds on HP-UX 11.00,
869 *with* threads, and passes the test suite.
870
Tim Peters7a33d8b2001-11-05 02:51:07 +0000871- Thanks to a series of patches from Michael Muller, Python may build
872 again under OS/2 Visual Age C++.
873
Guido van Rossum49192142001-10-24 20:51:44 +0000874- Updated RISCOS port by Dietmar Schwertberger.
875
Tim Peters84362bc2001-10-19 17:55:30 +0000876Tests
877
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000878- Added a test script for the curses module. It isn't run automatically;
879 regrtest.py must be run with '-u curses' to enable it.
880
Tim Peters84362bc2001-10-19 17:55:30 +0000881Windows
882
Barry Warsaw012852b2001-11-16 16:17:27 +0000883Mac
884
885- PythonScript has been moved to unsupported and is slated to be
886 removed completely in the next release.
887
888- It should now be possible to build applets that work on both OS9 and
889 OSX.
890
891- The core is now linked with CoreServices not Carbon; as a side
892 result, default 8bit encoding on OSX is now ASCII.
893
894- Python should now build on OSX 10.1.1
895
Tim Peters84362bc2001-10-19 17:55:30 +0000896
Tim Petersabf925f2001-09-28 21:53:42 +0000897What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000898Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000899===========================
900
901Type/class unification and new-style classes
902
Guido van Rossum687ae002001-10-15 22:03:32 +0000903- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000904 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000905 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000906 remains: the __dict__ of a new-style class is a read-only proxy; you
907 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000908 __defined__ attribute of new-style types no longer exists, for lack
909 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000910 future a __cache__ may be resurrected with a similar function, if I
911 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000912
Tim Peters1c9ca872001-10-04 06:43:12 +0000913- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
914 always returned None, even when there was a class docstring).
915
916- doctest now finds and runs docstrings attached to new-style classes,
917 class methods, static methods, and properties.
918
Guido van Rossum9074ef62001-10-16 21:34:49 +0000919Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000920
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000921- A very subtle syntactical pitfall in list comprehensions was fixed.
922 For example: [a+b for a in 'abc', for b in 'def']. The comma in
923 this example is a mistake. Previously, this would silently let 'a'
924 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
925 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
926 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
927 Note that [a for a in <singleton>] is a convoluted way to say
928 [<singleton>] anyway, so it's not like any expressiveness is lost.
929
Guido van Rossum9074ef62001-10-16 21:34:49 +0000930- getattr(obj, name, default) now only catches AttributeError, as
931 documented, rather than returning the default value for all
932 exceptions (which could mask bugs in a __getattr__ hook, for
933 example).
934
Fred Drakecb7a6b52001-10-22 18:41:51 +0000935- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000936 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000937 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000938 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000939
Guido van Rossum1c486092001-10-19 02:05:35 +0000940- unicode(obj) now behaves more like str(obj), accepting arbitrary
941 objects, and calling a __unicode__ method if it exists.
942 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000943 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000944
Barry Warsawf6fb1712001-10-19 05:35:40 +0000945- isinstance() now allows any object as the first argument and a
946 class, a type or something with a __bases__ tuple attribute for the
947 second argument. The second argument may also be a tuple of a
948 class, type, or something with __bases__, in which case isinstance()
949 will return true if the first argument is an instance of any of the
950 things contained in the second argument tuple. E.g.
951
952 isinstance(x, (A, B))
953
954 returns true if x is an instance of A or B.
955
Guido van Rossum9074ef62001-10-16 21:34:49 +0000956Extension modules
957
958- thread.start_new_thread() now returns the thread ID (previously None).
959
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000960- binascii has now two quopri support functions, a2b_qp and b2a_qp.
961
Guido van Rossumc524d952001-10-19 01:31:59 +0000962- readline now supports setting the startup_hook and the
963 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000964
Guido van Rossumc524d952001-10-19 01:31:59 +0000965- os and posix supports chroot(), setgroups() and unsetenv() where
966 available. The stat(), fstat(), statvfs() and fstatvfs() functions
967 now return "pseudo-sequences" -- the various fields can now be
968 accessed as attributes (e.g. os.stat("/").st_mtime) but for
969 backwards compatibility they also behave as a fixed-length sequence.
970 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000971 attributes.
972
973- time: localtime(), gmtime() and strptime() now return a
974 pseudo-sequence similar to the os.stat() return value, with
975 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000976
Guido van Rossum9074ef62001-10-16 21:34:49 +0000977- Decompression objects in the zlib module now accept an optional
978 second parameter to decompress() that specifies the maximum amount
979 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000980
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000981- optional SSL support in the socket module now exports OpenSSL
982 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
983 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000984 automatically seed its PRNG. Also, the keyfile and certfile
985 arguments to socket.ssl() are now optional.
986
987- posixmodule (and by extension, the os module on POSIX platforms) now
988 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000989
Guido van Rossum9074ef62001-10-16 21:34:49 +0000990Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000991
Tim Peters7402f792001-10-02 03:53:41 +0000992- doctest now excludes functions and classes not defined by the module
993 being tested, thanks to Tim Hochberg.
994
Fred Drakecb7a6b52001-10-22 18:41:51 +0000995- HotShot, a new profiler implemented using a C-based callback, has
996 been added. This substantially reduces the overhead of profiling,
997 but it is still quite preliminary. Support modules and
998 documentation will be added in upcoming releases (before 2.2 final).
999
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001000- profile now produces correct output in situations where an exception
1001 raised in Python is cleared by C code (e.g. hasattr()). This used
1002 to cause wrong output, including spurious claims of recursive
1003 functions and attribution of time spent to the wrong function.
1004
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001005 The code and documentation for the derived OldProfile and HotProfile
1006 profiling classes was removed. The code hasn't worked for years (if
1007 you tried to use them, they raised exceptions). OldProfile
1008 intended to reproduce the behavior of the profiler Python used more
1009 than 7 years ago, and isn't interesting anymore. HotProfile intended
1010 to provide a faster profiler (but producing less information), and
1011 that's a worthy goal we intend to meet via a different approach (but
1012 without losing information).
1013
Tim Peterscce092d2001-10-09 05:31:56 +00001014- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001015 a much better system-specific calibration constant. The constant can
1016 now be specified in an instance constructor, or as a Profile class or
1017 instance variable, instead of by editing profile.py's source code.
1018 Calibration must still be done manually (see the docs for the profile
1019 module).
1020
1021 Note that Profile.calibrate() must be overriden by subclasses.
1022 Improving the accuracy required exploiting detailed knowledge of
1023 profiler internals; the earlier method abstracted away the details
1024 and measured a simplified model instead, but consequently computed
1025 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001026
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001027- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001028 which indicates whether output is intended for the header 'Q'
1029 encoding.
1030
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001031- The SocketServer.ThreadingMixIn class now closes the request after
1032 finish_request() returns. (Not when it errors out though.)
1033
Barry Warsawf6fb1712001-10-19 05:35:40 +00001034- The nntplib module's NNTP.body() method has grown a `file' argument
1035 to allow saving the message body to a file.
1036
1037- The email package has added a class email.Parser.HeaderParser which
1038 only parses headers and does not recurse into the message's body.
1039 Also, the module/class MIMEAudio has been added for representing
1040 audio data (contributed by Anthony Baxter).
1041
1042- ftplib should be able to handle files > 2GB.
1043
1044- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1045 ON, and OFF.
1046
Fred Drakecb7a6b52001-10-22 18:41:51 +00001047- xml.dom.minidom NodeList objects now support the length attribute
1048 and item() method as required by the DOM specifications.
1049
Guido van Rossumed554f62001-10-02 23:15:37 +00001050Tools/Demos
1051
1052- Demo/dns was removed. It no longer serves any purpose; a package
1053 derived from it is now maintained by Anthony Baxter, see
1054 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001055
Barry Warsawf6fb1712001-10-19 05:35:40 +00001056- The freeze tool has been made more robust, and two new options have
1057 been added: -X and -E.
1058
Tim Petersabf925f2001-09-28 21:53:42 +00001059Build
1060
Barry Warsawf6fb1712001-10-19 05:35:40 +00001061- configure will use CXX in LINKCC if CXX is used to build main() and
1062 the system requires to link a C++ main using the C++ compiler.
1063
Tim Petersabf925f2001-09-28 21:53:42 +00001064C API
1065
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001066- The documentation for the tp_compare slot is updated to require that
1067 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1068 not correct. This is not yet enforced but will be enforced in
1069 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1070 "NotImplemented". Right now, -1 should be used for an error return.
1071
Tim Petersd38b1c72001-09-30 05:09:37 +00001072- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1073 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1074 as long) arguments.
1075
Guido van Rossum3c288632001-10-16 21:13:49 +00001076- PyThread_start_new_thread() now returns a long int giving the thread
1077 ID, if one can be calculated; it returns -1 for error, 0 if no
1078 thread ID is calculated (this is an incompatible change, but only
1079 the thread module used this API). This code has only really been
1080 tested on Linux and Windows; other platforms please beware (and
1081 report any bugs or strange behavior).
1082
Guido van Rossum1c486092001-10-19 02:05:35 +00001083- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1084 input.
1085
Tim Petersabf925f2001-09-28 21:53:42 +00001086New platforms
1087
1088Tests
1089
1090Windows
1091
Tim Peters04cf1d32001-10-09 22:39:40 +00001092- Installer: If you install IDLE, and don't disable file-extension
1093 registration, a new "Edit with IDLE" context (right-click) menu entry
1094 is created for .py and .pyw files.
1095
Tim Peters1ce3cf72001-10-01 17:58:40 +00001096- The signal module now supports SIGBREAK on Windows, thanks to Steven
1097 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1098 action remains to call Win32 ExitProcess(). This can be changed via
1099 signal.signal(). For example:
1100
1101 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1102 # (SIGINT) behavior.
1103 import signal
1104 signal.signal(signal.SIGBREAK,
1105 signal.default_int_handler)
1106
1107 try:
1108 while 1:
1109 pass
1110 except KeyboardInterrupt:
1111 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1112 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1113 # program without the possibility for any Python-level cleanup).
1114 print "Clean exit"
1115
Tim Petersabf925f2001-09-28 21:53:42 +00001116
Tim Petersb07352e2001-09-08 01:25:47 +00001117What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001118Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001119===========================
1120
Guido van Rossum808eea72001-09-25 04:15:41 +00001121Type/class unification and new-style classes
1122
1123- pydoc and inspect are now aware of new-style classes;
1124 e.g. help(list) at the interactive prompt now shows proper
1125 documentation for all operations on list objects.
1126
1127- Applications using Jim Fulton's ExtensionClass module can now safely
1128 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1129 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1130 examples also work again. It is hoped that Gtk and Boost also work
1131 with 2.2a4 and beyond. (If you can confirm this, please write
1132 webmaster@python.org; if there are still problems, please open a bug
1133 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001134
Tim Peters66c1a522001-09-24 21:17:50 +00001135- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001136 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001137 in the constructed property object. fget, fset and fdel weren't
1138 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1139 associate a docstring with a property.
1140
Guido van Rossum808eea72001-09-25 04:15:41 +00001141- Comparison overloading is now more completely implemented. For
1142 example, a str subclass instance can properly be compared to a str
1143 instance, and it can properly overload comparison. Ditto for most
1144 other built-in object types.
1145
1146- The repr() of new-style classes has changed; instead of <type
1147 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1148 *except* for built-in types, which are still rendered as <type
1149 'Foo'> (to avoid upsetting existing code that might parse or
1150 otherwise rely on repr() of certain type objects).
1151
1152- The repr() of new-style objects is now always <Foo object at XXX>;
1153 previously, it was sometimes <Foo instance at XXX>.
1154
1155- For new-style classes, what was previously called __getattr__ is now
1156 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001157 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001158 one in classic classes is defined which is called only if regular
1159 attribute access raises AttributeError; to catch *all* attribute
1160 access, you can use __getattribute__ (for new-style classes). If
1161 both are defined, __getattribute__ is called first, and if it raises
1162 AttributeError, __getattr__ is called.
1163
1164- The __class__ attribute of new-style objects can be assigned to.
1165 The new class must have the same C-level object layout as the old
1166 class.
1167
1168- The builtin file type can be subclassed now. In the usual pattern,
1169 "file" is the name of the builtin type, and file() is a new builtin
1170 constructor, with the same signature as the builtin open() function.
1171 file() is now the preferred way to open a file.
1172
1173- Previously, __new__ would only see sequential arguments passed to
1174 the type in a constructor call; __init__ would see both sequential
1175 and keyword arguments. This made no sense whatsoever any more, so
1176 now both __new__ and __init__ see all arguments.
1177
1178- Previously, hash() applied to an instance of a subclass of str or
1179 unicode always returned 0. This has been repaired.
1180
1181- Previously, an operation on an instance of a subclass of an
1182 immutable type (int, long, float, complex, tuple, str, unicode),
1183 where the subtype didn't override the operation (and so the
1184 operation was handled by the builtin type), could return that
1185 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001186 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001187 with the same value as s.
1188
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001189- Provisional support for pickling new-style objects has been added.
1190
Guido van Rossum808eea72001-09-25 04:15:41 +00001191Core
1192
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001193- file.writelines() now accepts any iterable object producing strings.
1194
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001195- PyUnicode_FromEncodedObject() now works very much like
1196 PyObject_Str(obj) in that it tries to use __str__/tp_str
1197 on the object if the object is not a string or buffer. This
1198 makes unicode() behave like str() when applied to non-string/buffer
1199 objects.
1200
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001201- PyFile_WriteObject now passes Unicode objects to the file's write
1202 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001203 of a print statement must support Unicode objects, i.e. they must
1204 at least convert them into ASCII strings.
1205
Guido van Rossum624c8af2001-09-18 15:21:04 +00001206- Thread scheduling on Solaris should be improved; it is no longer
1207 necessary to insert a small sleep at the start of a thread in order
1208 to let other runnable threads be scheduled.
1209
Tim Petersb07352e2001-09-08 01:25:47 +00001210Library
1211
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001212- StringIO.StringIO instances and cStringIO.StringIO instances support
1213 read character buffer compatible objects for their .write() methods.
1214 These objects are converted to strings and then handled as such
1215 by the instances.
1216
Barry Warsaw2f600732001-09-24 04:28:10 +00001217- The "email" package has been added. This is basically a port of the
1218 mimelib package <http://sf.net/projects/mimelib> with API changes
1219 and some implementations updated to use iterators and generators.
1220
Tim Peters8a9c2842001-09-22 21:30:22 +00001221- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1222 restores the ability of Tools/scripts/ndiff.py to start producing output
1223 before the entire comparison is complete.
1224
Barry Warsaw58b072d2001-09-22 04:44:21 +00001225- StringIO.StringIO instances and cStringIO.StringIO instances support
1226 iteration just like file objects (i.e. their .readline() method is
1227 called for each iteration until it returns an empty string).
1228
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001229- The codecs module has grown four new helper APIs to access
1230 builtin codecs: getencoder(), getdecoder(), getreader(),
1231 getwriter().
1232
Guido van Rossum624c8af2001-09-18 15:21:04 +00001233- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1234 simplifies writing XML RPC servers.
1235
Barry Warsaw647d5e82001-09-28 17:01:02 +00001236- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001237 after interpretation of symbolic links. On non-Unix systems, this
1238 is an alias for os.path.abspath().
1239
Tim Peters16a77ad2001-09-08 04:00:12 +00001240- operator.indexOf() (PySequence_Index() in the C API) now works with any
1241 iterable object.
1242
Guido van Rossum624c8af2001-09-18 15:21:04 +00001243- smtplib now supports various authentication and security features of
1244 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001245
Guido van Rossum624c8af2001-09-18 15:21:04 +00001246- hmac: a new module implementing keyed hashing for message
1247 authentication.
1248
1249- mimetypes now recognizes more extensions and file types. At the
1250 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001251
Guido van Rossum624c8af2001-09-18 15:21:04 +00001252- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001253 Python 2.2 bytecode generation. It has also been promoted from a
1254 Tool to a standard library package. (Tools/compiler still exists as
1255 a sample driver.)
1256
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001257Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001258
Tim Petersb07352e2001-09-08 01:25:47 +00001259Build
1260
Guido van Rossum624c8af2001-09-18 15:21:04 +00001261- Large file support (LFS) is now automatic when the platform supports
1262 it; no more manual configuration tweaks are needed. On Linux, at
1263 least, it's possible to have a system whose C library supports large
1264 files but whose kernel doesn't; in this case, large file support is
1265 still enabled but doesn't do you any good unless you upgrade your
1266 kernel or share your Python executable with another system whose
1267 kernel has large file support.
1268
1269- The configure script now supplies plausible defaults in a
1270 cross-compilation environment. This doesn't mean that the supplied
1271 values are always correct, or that cross-compilation now works
1272 flawlessly -- but it's a first step (and it shuts up most of
1273 autoconf's warnings about AC_TRY_RUN).
1274
1275- The Unix build is now a bit less chatty, courtesy of the parser
1276 generator. The build is completely silent (except for errors) when
1277 using "make -s", thanks to a -q option to setup.py.
1278
Tim Petersb07352e2001-09-08 01:25:47 +00001279C API
1280
Guido van Rossum624c8af2001-09-18 15:21:04 +00001281- The "structmember" API now supports some new flag bits to deny read
1282 and/or write access to attributes in restricted execution mode.
1283
Tim Petersb07352e2001-09-08 01:25:47 +00001284New platforms
1285
Guido van Rossum624c8af2001-09-18 15:21:04 +00001286- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1287 (http://familiar.handhelds.org).
1288
Tim Petersb07352e2001-09-08 01:25:47 +00001289Tests
1290
Tim Peters8a9c2842001-09-22 21:30:22 +00001291- The "classic" standard tests, which work by comparing stdout to
1292 an expected-output file under Lib/test/output/, no longer stop at
1293 the first mismatch. Instead the test is run to completion, and a
1294 variant of ndiff-style comparison is used to report all differences.
1295 This is much easier to understand than the previous style of reporting.
1296
1297- The unittest-based standard tests now use regrtest's test_main()
1298 convention, instead of running as a side-effect of merely being
1299 imported. This allows these tests to be run in more natural and
1300 flexible ways as unittests, outside the regrtest framework.
1301
1302- regrtest.py is much better integrated with unittest and doctest now,
1303 especially in regard to reporting errors.
1304
Tim Petersb07352e2001-09-08 01:25:47 +00001305Windows
1306
Guido van Rossum624c8af2001-09-18 15:21:04 +00001307- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001308 that support it (NTFS under Windows 2000). See "What's New in
1309 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001310
Tim Petersb07352e2001-09-08 01:25:47 +00001311
Tim Petersedc99312001-08-22 21:36:50 +00001312What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001313Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001314===========================
1315
1316Core
1317
Tim Peters9fffa3e2001-09-04 05:14:19 +00001318- Conversion of long to float now raises OverflowError if the long is too
1319 big to represent as a C double.
1320
Tim Peters32f453e2001-09-03 08:35:41 +00001321- The 3-argument builtin pow() no longer allows a third non-None argument
1322 if either of the first two arguments is a float, or if both are of
1323 integer types and the second argument is negative (in which latter case
1324 the arguments are converted to float, so this is really the same
1325 restriction).
1326
Tim Peters5d2b77c2001-09-03 05:47:38 +00001327- The builtin dir() now returns more information, and sometimes much
1328 more, generally naming all attributes of an object, and all attributes
1329 reachable from the object via its class, and from its class's base
1330 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1331 an empty list. In 2.2a3,
1332
1333 >>> dir([])
1334 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1335 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1336 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1337 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1338 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1339 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1340 'reverse', 'sort']
1341
1342 dir(module) continues to return only the module's attributes, though.
1343
Tim Petersbdee63f2001-09-02 03:40:59 +00001344- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001345 than raising OverflowError. This is a partial implementation of PEP
1346 237. You can use -Wdefault::OverflowWarning to enable a warning for
1347 this situation, and -Werror::OverflowWarning to revert to the old
1348 OverflowError exception.
1349
Guido van Rossum61c345f2001-09-04 03:26:15 +00001350- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001351 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001352 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1353 -Qold, meaning the / operator has its classic meaning and no
1354 warnings are issued. Using -Qwarn issues a run-time warning about
1355 all uses of classic division for int and long arguments; -Qwarnall
1356 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001357 (for use with fixdiv.py).
1358 [Note: the remainder of this paragraph (preserved below) became
1359 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1360 <obsolete>
1361 Using -Qnew is questionable; it turns on new division by default, but
1362 only in the __main__ module. You can usefully combine -Qwarn or
1363 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1364 warns about classic division everywhere else.
1365 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001366
Tim Petersbdee63f2001-09-02 03:40:59 +00001367- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001368 long, float, str, unicode, and tuple. (The types complex, list and
1369 dictionary can also be subclassed; this was introduced earlier.)
1370 Note that restrictions apply when subclassing immutable built-in
1371 types: you can only affect the value of the instance by overloading
1372 __new__. You can add mutable attributes, and the subclass instances
1373 will have a __dict__ attribute, but you cannot change the "value"
1374 (as implemented by the base class) of an immutable subclass instance
1375 once it is created.
1376
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001377- The dictionary constructor now takes an optional argument, a
1378 mapping-like object, and initializes the dictionary from its
1379 (key, value) pairs.
1380
Tim Petersbdee63f2001-09-02 03:40:59 +00001381- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001382 "cooperative super calls" in a multiple inheritance setting. For an
1383 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1384
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001385- A new built-in type, property, has been added. This enables the
1386 creation of "properties". These are attributes implemented by
1387 getter and setter functions (or only one of these for read-only or
1388 write-only attributes), without the need to override __getattr__.
1389 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001390
Tim Petersbdee63f2001-09-02 03:40:59 +00001391- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001392 liberalized, to allow leading zeroes. Examples of literals now
1393 legal that were SyntaxErrors before:
1394
1395 00.0 0e3 0100j 07.5 00000000000000000008.
1396
Tim Petersbdee63f2001-09-02 03:40:59 +00001397- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001398 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1399
Tim Petersedc99312001-08-22 21:36:50 +00001400Library
1401
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001402- telnetlib includes symbolic names for the options, and support for
1403 setting an option negotiation callback.
1404
Tim Petersa40c7932001-09-05 22:36:56 +00001405- The new C standard no longer requires that math libraries set errno to
1406 ERANGE on overflow. For platform libraries that exploit this new
1407 freedom, Python's overflow-checking was wholly broken. A new overflow-
1408 checking scheme attempts to repair that, but may not be reliable on all
1409 platforms (C doesn't seem to provide anything both useful and portable
1410 in this area anymore).
1411
Martin v. Löwis44f86962001-09-05 13:44:54 +00001412- Asynchronous timeout actions are available through the new class
1413 threading.Timer.
1414
Tim Peters78526162001-09-05 00:53:45 +00001415- math.log and math.log10 now return sensible results for even huge
1416 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1417
Tim Petersbdee63f2001-09-02 03:40:59 +00001418- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001419 currently held. See the docs for the imp module.
1420
Tim Petersbdee63f2001-09-02 03:40:59 +00001421- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001422 dumps containing ints written on platforms where Python ints are 8 bytes.
1423 When read on a box where Python ints are 4 bytes, such values are
1424 converted to Python longs.
1425
Tim Petersbdee63f2001-09-02 03:40:59 +00001426- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001427 code objects is no longer allowed. This plugs a security hole.
1428
Steve Purcell6091cd62001-09-06 16:05:17 +00001429- unittest.TestResult instances no longer store references to tracebacks
1430 generated by test failures. This prevents unexpected dangling references
1431 to objects that should be garbage collected between tests.
1432
Tim Petersedc99312001-08-22 21:36:50 +00001433Tools
1434
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001435- Tools/scripts/fixdiv.py has been added which can be used to fix
1436 division operators as per PEP 238.
1437
Tim Petersedc99312001-08-22 21:36:50 +00001438Build
1439
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001440- If you are an adventurous person using Mac OS X you may want to look at
1441 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1442 application, which can be used for experimenting with Carbon or Cocoa.
1443 Discussion of this on pythonmac-sig, please.
1444
Tim Peters7eea37e2001-09-04 22:08:56 +00001445C API
1446
1447- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001448
Tim Peters9fffa3e2001-09-04 05:14:19 +00001449- Note that PyLong_AsDouble can fail! This has always been true, but no
1450 callers checked for it. It's more likely to fail now, because overflow
1451 errors are properly detected now. The proper way to check:
1452
1453 double x = PyLong_AsDouble(some_long_object);
1454 if (x == -1.0 && PyErr_Occurred()) {
1455 /* The conversion failed. */
1456 }
1457
Tim Petersbdee63f2001-09-02 03:40:59 +00001458- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001459 compile but will not participate in GC. To upgrade an extension
1460 module:
1461
1462 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001463
Neil Schemenauer4042c692001-08-30 15:38:01 +00001464 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1465 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001466
Neil Schemenauer4042c692001-08-30 15:38:01 +00001467 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1468 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001469
Neil Schemenauer4042c692001-08-30 15:38:01 +00001470 - remove PyGC_HEAD_SIZE from object size calculations
1471
1472 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1473
Tim Petersbdee63f2001-09-02 03:40:59 +00001474- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001475 These can be used safely to construct string objects from a
1476 sprintf-style format string (similar to the format string supported
1477 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001478
Tim Petersedc99312001-08-22 21:36:50 +00001479New platforms
1480
Tim Petersb7da0902001-09-02 23:01:43 +00001481- Stephen Hansen contributed patches sufficient to get a clean compile
1482 under Borland C (Windows), but he reports problems running it and ran
1483 out of time to complete the port. Volunteers? Expect a MemoryError
1484 when importing the types module; this is probably shallow, and
1485 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001486
Tim Petersedc99312001-08-22 21:36:50 +00001487Tests
1488
1489Windows
1490
Tim Peters6e13a562001-09-06 00:32:15 +00001491- Large file support is now enabled on Win32 platforms as well as on
1492 Win64. This means that, for example, you can use f.tell() and f.seek()
1493 to manipulate files larger than 2 gigabytes (provided you have enough
1494 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001495 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1496 filesize limit, and large file support makes no difference there.
1497 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1498 NTFS has no practical limit on file size, and files of any size can be
1499 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001500
Tim Petersbdee63f2001-09-02 03:40:59 +00001501- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001502 points to command.com (patch from Brian Quinlan).
1503
Tim Petersedc99312001-08-22 21:36:50 +00001504
Tim Peters20f51a72001-07-21 02:31:40 +00001505What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001506Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001507===========================
1508
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001509Build
1510
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001511- Tim Peters developed a brand new Windows installer using Wise 8.1,
1512 generously donated to us by Wise Solutions.
1513
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001514- configure supports a new option --enable-unicode, with the values
1515 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1516 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001517
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001518- A new configure option --enable-framework builds a Mac OS X framework,
1519 which "make frameworkinstall" will install. This provides a starting
1520 point for more mac-like functionality, join pythonmac-sig@python.org
1521 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001522
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001523- The NeXT platform is no longer supported.
1524
1525- The `new' module is now statically linked.
1526
Tim Peters0afb6092001-08-15 06:06:44 +00001527Tools
1528
1529- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001530 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001531 the module docstring for details.
1532
Tim Peters20f51a72001-07-21 02:31:40 +00001533Tests
1534
Tim Peters5e824c32001-08-12 22:25:01 +00001535- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001536 platforms, allowing to give clearer test result output. regrtest
1537 also has optional --use/-u switch to run normally disabled tests
1538 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001539
Tim Peters20f51a72001-07-21 02:31:40 +00001540- Several new tests in the standard test suite, with special thanks to
1541 Nick Mathewson.
1542
1543Core
1544
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001545- The floor division operator // has been added as outlined in PEP
1546 238. The / operator still provides classic division (and will until
1547 Python 3.0) unless "from __future__ import division" is included, in
1548 which case the / operator will provide true division. The operator
1549 module provides truediv() and floordiv() functions. Augmented
1550 assignment variants are included, as are the equivalent overloadable
1551 methods and C API methods. See the PEP for a full discussion:
1552 <http://python.sf.net/peps/pep-0238.html>
1553
Tim Peters6cd6a822001-08-17 22:11:27 +00001554- Future statements are now effective in simulated interactive shells
1555 (like IDLE). This should "just work" by magic, but read Michael
1556 Hudson's "Future statements in simulated shells" PEP 264 for full
1557 details: <http://python.sf.net/peps/pep-0264.html>.
1558
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001559- The type/class unification (PEP 252-253) was integrated into the
1560 trunk and is not so tentative any more (the exact specification of
1561 some features is still tentative). A lot of work has done on fixing
1562 bugs and adding robustness and features (performance still has to
1563 come a long way).
1564
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001565- Warnings about a mismatch in the Python API during extension import
1566 now use the Python warning framework (which makes it possible to
1567 write filters for these warnings).
1568
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001569- A function's __dict__ (aka func_dict) will now always be a
1570 dictionary. It used to be possible to delete it or set it to None,
1571 but now both actions raise TypeErrors. It is still legal to set it
1572 to a dictionary object. Getting func.__dict__ before any attributes
1573 have been assigned now returns an empty dictionary instead of None.
1574
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001575- A new command line option, -E, was added which disables the use of
1576 all environment variables, or at least those that are specifically
1577 significant to Python. Usually those have a name starting with
1578 "PYTHON". This was used to fix a problem where the tests fail if
1579 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1580 older distribution.
1581
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001582Library
1583
Tim Peters5e824c32001-08-12 22:25:01 +00001584- New class Differ and new functions ndiff() and restore() in difflib.py.
1585 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001586 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001587
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001588- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1589 value using the minimal quoting required for the value; more
1590 reliable than using xml.sax.saxutils.escape() for attribute values.
1591
1592- Readline completion support for cmd.Cmd was added.
1593
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001594- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1595
1596- Added function threading.BoundedSemaphore()
1597
1598- Added Ka-Ping Yee's cgitb.py module.
1599
1600- The `new' module now exposes the CO_xxx flags.
1601
Martin v. Löwis560da622001-11-24 09:24:51 +00001602- The gc module offers the get_referents function.
1603
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001604New platforms
1605
1606C API
1607
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001608- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1609 which provide a cross-platform implementations for the
1610 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1611 the standard sprintf() and vsprintf() C lib APIs, these versions
1612 apply bounds checking on the used buffer which enhances protection
1613 against buffer overruns.
1614
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001615- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001616 and extensions using different Unicode widths is rendered next to
1617 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001618 will result in an ImportError. Unicode extensions writers must make
1619 sure to check the Unicode width compatibility in their extensions by
1620 using at least one of the mangled Unicode APIs in the extension.
1621
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001622- Two new flags METH_NOARGS and METH_O are available in method definition
1623 tables to simplify implementation of methods with no arguments and a
1624 single untyped argument. Calling such methods is more efficient than
1625 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1626 deprecated.
1627
Tim Petersc1731372001-08-04 08:12:36 +00001628Windows
1629
1630- "import module" now compiles module.pyw if it exists and nothing else
1631 relevant is found.
1632
Tim Peters20f51a72001-07-21 02:31:40 +00001633
Guido van Rossum55a78992001-07-17 17:22:32 +00001634What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001635Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001636===========================
1637
1638Core
Tim Petersa814db52001-05-14 07:05:58 +00001639
Tim Peters6d6c1a32001-08-02 04:15:00 +00001640- TENTATIVELY, a large amount of code implementing much of what's
1641 described in PEP 252 (Making Types Look More Like Classes) and PEP
1642 253 (Subtyping Built-in Types) was added. This will be released
1643 with Python 2.2a1. Documentation will be provided separately
1644 through http://www.python.org/2.2/. The purpose of releasing this
1645 with Python 2.2a1 is to test backwards compatibility. It is
1646 possible, though not likely, that a decision is made not to release
1647 this code as part of 2.2 final, if any serious backwards
1648 incompapatibilities are found during alpha testing that cannot be
1649 repaired.
1650
Guido van Rossum55a78992001-07-17 17:22:32 +00001651- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001652 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001653 more 'yield' statements. See PEP 255. Since this adds a new
1654 keyword to the language, this feature must be enabled by including a
1655 future statement: "from __future__ import generators" (see PEP 236).
1656 Generators will become a standard feature in a future release
1657 (probably 2.3). Without this future statement, 'yield' remains an
1658 ordinary identifier, but a warning is issued each time it is used.
1659 (These warnings currently don't conform to the warnings framework of
1660 PEP 230; we intend to fix this in 2.2a2.)
1661
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001662- The UTF-16 codec was modified to be more RFC compliant. It will now
1663 only remove BOM characters at the start of the string and then
1664 only if running in native mode (UTF-16-LE and -BE won't remove a
1665 leading BMO character).
1666
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001667- Strings now have a new method .decode() to complement the already
1668 existing .encode() method. These two methods provide direct access
1669 to the corresponding decoders and encoders of the registered codecs.
1670
1671 To enhance the usability of the .encode() method, the special
1672 casing of Unicode object return values was dropped (Unicode objects
1673 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001674
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001675 Both methods will now return whatever the codec in charge of the
1676 requested encoding returns as object, e.g. Unicode codecs will
1677 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1678 will return u"äöü"). This enables codec writer to create codecs
1679 for various simple to use conversions.
1680
1681 New codecs were added to demonstrate these new features (the .encode()
1682 and .decode() columns indicate the type of the returned objects):
1683
1684 Name | .encode() | .decode() | Description
1685 ----------------------------------------------------------------------
1686 uu | string | string | UU codec (e.g. for email)
1687 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001688 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001689 zlib | string | string | zlib compression
1690 hex | string | string | 2-byte hex codec
1691 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1692
Mark Hammond2a0af792001-05-14 03:09:36 +00001693- Some operating systems now support the concept of a default Unicode
1694 encoding for file system operations. Notably, Windows supports 'mbcs'
1695 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001696 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001697 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001698
1699 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001700 functions that return filenames (such as os.listdir()) to return Python
1701 string objects pre-encoded using the default file system encoding for
1702 the platform. As this encoding is likely to be different from Python's
1703 default encoding, converting this name to a Unicode object before passing
1704 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001705 would attempt to use its default encoding (generally ASCII) rather than
1706 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001707
Tim Petersa814db52001-05-14 07:05:58 +00001708 In general, this change simply removes surprises when working with
1709 Unicode and the file system, making these operations work as you expect,
1710 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001711 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001712
Tim Peters61dff2b2001-05-08 15:43:37 +00001713- Float (and complex) literals in source code were evaluated to full
1714 precision only when running from a .py file; the same code loaded from a
1715 .pyc (or .pyo) file could suffer numeric differences starting at about the
1716 12th significant decimal digit. For example, on a machine with IEEE-754
1717 floating arithmetic,
1718
1719 x = 9007199254740992.0
1720 print long(x)
1721
1722 printed 9007199254740992 if run directly from .py, but 9007199254740000
1723 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1724 str(float) instead of repr(float) when building code objects. marshal
1725 now uses repr(float) instead, which should reproduce floats to full
1726 machine precision (assuming the platform C float<->string I/O conversion
1727 functions are of good quality).
1728
1729 This may cause floating-point results to change in some cases, and
1730 usually for the better, but may also cause numerically unstable
1731 algorithms to break.
1732
Tim Peters2f228e72001-05-13 00:19:31 +00001733- The implementation of dicts suffers fewer collisions, which has speed
1734 benefits. However, the order in which dict entries appear in dict.keys(),
1735 dict.values() and dict.items() may differ from previous releases for a
1736 given dict. Nothing is defined about this order, so no program should
1737 rely on it. Nevertheless, it's easy to write test cases that rely on the
1738 order by accident, typically because of printing the str() or repr() of a
1739 dict to an "expected results" file. See Lib/test/test_support.py's new
1740 sortdict(dict) function for a simple way to display a dict in sorted
1741 order.
1742
Tim Peters7a3bfc32001-06-12 01:22:22 +00001743- Many other small changes to dicts were made, resulting in faster
1744 operation along the most common code paths.
1745
Guido van Rossum10315822001-05-01 20:54:30 +00001746- Dictionary objects now support the "in" operator: "x in dict" means
1747 the same as dict.has_key(x).
1748
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001749- The update() method of dictionaries now accepts generic mapping
1750 objects. Specifically the argument object must support the .keys()
1751 and __getitem__() methods. This allows you to say, for example,
1752 {}.update(UserDict())
1753
Guido van Rossum10315822001-05-01 20:54:30 +00001754- Iterators were added; this is a generalized way of providing values
1755 to a for loop. See PEP 234. There's a new built-in function iter()
1756 to return an iterator. There's a new protocol to get the next value
1757 from an iterator using the next() method (in Python) or the
1758 tp_iternext slot (in C). There's a new protocol to get iterators
1759 using the __iter__() method (in Python) or the tp_iter slot (in C).
1760 Iterating (i.e. a for loop) over a dictionary generates its keys.
1761 Iterating over a file generates its lines.
1762
Tim Petersf553f892001-05-01 20:45:31 +00001763- The following functions were generalized to work nicely with iterator
1764 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001765 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001766 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1767 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001768 join() method of strings
1769 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001770 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1771 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001772 right-hand side of assignment statements with multiple targets, such as
1773 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001774
Tim Petersd85e1022001-05-11 21:51:48 +00001775- Accessing module attributes is significantly faster (for example,
1776 random.random or os.path or yourPythonModule.yourAttribute).
1777
Tim Peterse63415e2001-05-08 04:38:29 +00001778- Comparing dictionary objects via == and != is faster, and now works even
1779 if the keys and values don't support comparisons other than ==.
1780
Tim Peters95bf9392001-05-10 08:32:44 +00001781- Comparing dictionaries in ways other than == and != is slower: there were
1782 insecurities in the dict comparison implementation that could cause Python
1783 to crash if the element comparison routines for the dict keys and/or
1784 values mutated the dicts. Making the code bulletproof slowed it down.
1785
Tim Peterseb28ef22001-06-02 05:27:19 +00001786- Collisions in dicts are resolved via a new approach, which can help
1787 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001788 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001789 faster now. Thanks to Christian Tismer for pointing out the cause and
1790 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001791
Tim Peters52e155e2001-06-16 05:42:57 +00001792- repr() is much faster for large containers (dict, list, tuple).
1793
1794
Tim Petersa814db52001-05-14 07:05:58 +00001795Library
1796
Fred Drake960fdf92001-07-20 18:38:26 +00001797- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1798 were added to the string module. These a locale-indenpendent
1799 constants, unlike letters, lowercase, and uppercase. These are now
1800 use in appropriate locations in the standard library.
1801
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001802- The flags used in dlopen calls can now be configured using
1803 sys.setdlopenflags and queried using sys.getdlopenflags.
1804
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001805- Fredrik Lundh's xmlrpclib is now a standard library module. This
1806 provides full client-side XML-RPC support. In addition,
1807 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1808 one asyncore-based). Thanks to Eric Raymond for the documentation.
1809
Guido van Rossum643d3912001-07-05 14:46:25 +00001810- The xrange() object is simplified: it no longer supports slicing,
1811 repetition, comparisons, efficient 'in' checking, the tolist()
1812 method, or the start, stop and step attributes. See PEP 260.
1813
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001814- A new function fnmatch.filter to filter lists of file names was added.
1815
Barry Warsawffd674d2001-05-22 16:00:10 +00001816- calendar.py uses month and day names based on the current locale.
1817
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001818- strop is now *really* obsolete (this was announced before with 1.6),
1819 and issues DeprecationWarning when used (except for the four items
1820 that are still imported into string.py).
1821
Tim Petersa814db52001-05-14 07:05:58 +00001822- Cookie.py now sorts key+value pairs by key in output strings.
1823
1824- pprint.isrecursive(object) didn't correctly identify recursive objects.
1825 Now it does.
1826
Tim Peters95b3f782001-05-14 18:39:41 +00001827- pprint functions now much faster for large containers (tuple, list, dict).
1828
Tim Peters7b9542a2001-06-10 23:40:19 +00001829- New 'q' and 'Q' format codes in the struct module, corresponding to C
1830 types "long long" and "unsigned long long" (on Windows, __int64). In
1831 native mode, these can be used only when the platform C compiler supports
1832 these types (when HAVE_LONG_LONG is #define'd by the Python config
1833 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001834 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1835 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001836
Guido van Rossum83213cc2001-06-12 16:48:52 +00001837- The site module installs a new built-in function 'help' that invokes
1838 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1839 it displays a message reminding the user to use 'help()' or
1840 'help(object)'.
1841
Tim Petersa814db52001-05-14 07:05:58 +00001842Tests
1843
1844- New test_mutants.py runs dict comparisons where the key and value
1845 comparison operators mutute the dicts randomly during comparison. This
1846 rapidly causes Python to crash under earlier releases (not for the faint
1847 of heart: it can also cause Win9x to freeze or reboot!).
1848
1849- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001850 pprint.isreadable() return sensible results. Also verifies that simple
1851 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001852
Tim Peters4324aa32001-05-28 22:30:08 +00001853C API
1854
1855- Removed the unused last_is_sticky argument from the internal
1856 _PyTuple_Resize(). If this affects you, you were cheating.
1857
1858
Guido van Rossum55a78992001-07-17 17:22:32 +00001859======================================================================
1860
1861
Guido van Rossumffe13be2001-04-16 18:46:45 +00001862What's New in Python 2.1 (final)?
1863=================================
1864
1865We only changed a few things since the last release candidate, all in
1866Python library code:
1867
1868- A bug in the locale module was fixed that affected locales which
1869 define no grouping for numeric formatting.
1870
1871- A few bugs in the weakref module's implementations of weak
1872 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1873 and the test suite was updated to check for these bugs.
1874
1875- An old bug in the os.path.walk() function (introduced in Python
1876 2.0!) was fixed: a non-existent file would cause an exception
1877 instead of being ignored.
1878
1879- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1880 PyChecker.
1881
1882
Guido van Rossum5b08f132001-04-16 02:05:23 +00001883What's New in Python 2.1c2?
1884===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001885
Guido van Rossum5b08f132001-04-16 02:05:23 +00001886A flurry of small changes, and one showstopper fixed in the nick of
1887time made it necessary to release another release candidate. The list
1888here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001889
Guido van Rossum5b08f132001-04-16 02:05:23 +00001890Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001891
Guido van Rossum5b08f132001-04-16 02:05:23 +00001892- Tim discovered a nasty bug in the dictionary code, caused by
1893 PyDict_Next() calling dict_resize(), and the GC code's use of
1894 PyDict_Next() violating an assumption in dict_items(). This was
1895 fixed with considerable amounts of band-aid, but the net effect is a
1896 saner and more robust implementation.
1897
1898- Made a bunch of symbols static that were accidentally global.
1899
1900Build and Ports
1901
1902- The setup.py script didn't check for a new enough version of zlib
1903 (1.1.3 is needed). Now it does.
1904
1905- Changed "make clean" target to also remove shared libraries.
1906
1907- Added a more general warning about the SGI Irix optimizer to README.
1908
1909Library
1910
1911- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1912 omitted the slash between host and file.html.
1913
1914- The mailbox module's _Mailbox class contained a completely broken
1915 and undocumented seek() method. Ripped it out.
1916
1917- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1918 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1919
1920- Fixed a few last-minute bugs in unittest.
1921
1922Extensions
1923
1924- Reverted the patch to the OpenSSL code in socketmodule.c to support
1925 RAND_status() and the EGD, and the subsequent patch that tried to
1926 fix it for pre-0.9.5 versions; the problem with the patch is that on
1927 some systems it issues a warning whenever socket is imported, and
1928 that's unacceptable.
1929
1930Tests
1931
1932- Fixed the pickle tests to work with "import test.test_pickle".
1933
1934- Tweaked test_locale.py to actually run the test Windows.
1935
1936- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1937 not "wb" (which is not a valid mode at all).
1938
1939- Fix pstats browser crashes. Import readline if it exists to make
1940 the user interface nicer.
1941
1942- Add "import thread" to the top of test modules that import the
1943 threading module (test_asynchat and test_threadedtempfile). This
1944 prevents test failures caused by a broken threading module resulting
1945 from a previously caught failed import.
1946
1947- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1948 needed on some platforms (e.g. Solaris 8) when the tests are run
1949 twice in succession.
1950
1951- Skip rather than fail test_sunaudiodev if no audio device is found.
1952
1953
1954What's New in Python 2.1c1?
1955===========================
1956
1957This list was significantly updated when 2.1c2 was released; the 2.1c1
1958release didn't mention most changes that were actually part of 2.1c1:
1959
1960Legal
1961
1962- Copyright was assigned to the Python Software Foundation (PSF) and a
1963 PSF license (very similar to the CNRI license) was added.
1964
1965- The CNRI copyright notice was updated to include 2001.
1966
1967Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001968
Guido van Rossumc9932722001-04-12 02:31:27 +00001969- After a public outcry, assignment to __debug__ is no longer illegal;
1970 instead, a warning is issued. It will become illegal in 2.2.
1971
Guido van Rossum5b08f132001-04-16 02:05:23 +00001972- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1973 "%#x" now always prepends "0x", even if the value is zero.
1974
1975- Fixed some nits in the bytecode compiler.
1976
1977- Fixed core dumps when calling certain kinds of non-functions.
1978
1979- Fixed various core dumps caused by reference count bugs.
1980
1981Build and Ports
1982
1983- Use INSTALL_SCRIPT to install script files.
1984
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001985- New port: SCO Unixware 7, by Billy G. Allie.
1986
Guido van Rossum5b08f132001-04-16 02:05:23 +00001987- Updated RISCOS port.
1988
1989- Updated BeOS port and notes.
1990
1991- Various other porting problems resolved.
1992
1993Library
1994
1995- The TERMIOS and SOCKET modules are now truly obsolete and
1996 unnecessary. Their symbols are incorporated in the termios and
1997 socket modules.
1998
1999- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
2000 better tests for pickling.
2001
2002- threading: make Condition.wait() robust against KeyboardInterrupt.
2003
2004- zipfile: add support to zipfile to support opening an archive
2005 represented by an open file rather than a file name. Fix bug where
2006 the archive was not properly closed. Fixed a bug in this bugfix
2007 where flush() was called for a read-only file.
2008
2009- imputil: added an uninstall() method to the ImportManager.
2010
2011- Canvas: fixed bugs in lower() and tkraise() methods.
2012
2013- SocketServer: API change (added overridable close_request() method)
2014 so that the TCP server can explicitly close the request.
2015
2016- pstats: Eric Raymond added a simple interactive statistics browser,
2017 invoked when the module is run as a script.
2018
2019- locale: fixed a problem in format().
2020
2021- webbrowser: made it work when the BROWSER environment variable has a
2022 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
2023 KDE 2. Fixed some other nits.
2024
2025- unittest: changes to allow using a different exception than
2026 AssertionError, and added a few more function aliases. Some other
2027 small changes.
2028
2029- urllib, urllib2: fixed redirect problems and a coupleof other nits.
2030
2031- asynchat: fixed a critical bug in asynchat that slipped through the
2032 2.1b2 release. Fixed another rare bug.
2033
2034- Fix some unqualified except: clauses (always a bad code example).
2035
2036XML
2037
2038- pyexpat: new API get_version_string().
2039
2040- Fixed some minidom bugs.
2041
2042Extensions
2043
2044- Fixed a core dump in _weakref. Removed the weakref.mapping()
2045 function (it adds nothing to the API).
2046
2047- Rationalized the use of header files in the readline module, to make
2048 it compile (albeit with some warnings) with the very recent readline
2049 4.2, without breaking for earlier versions.
2050
2051- Hopefully fixed a buffering problem in linuxaudiodev.
2052
2053- Attempted a fix to make the OpenSSL support in the socket module
2054 work again with pre-0.9.5 versions of OpenSSL.
2055
2056Tests
2057
2058- Added a test case for asynchat and asyncore.
2059
2060- Removed coupling between tests where one test failing could break
2061 another.
2062
2063Tools
2064
2065- Ping added an interactive help browser to pydoc, fixed some nits
2066 in the rest of the pydoc code, and added some features to his
2067 inspect module.
2068
2069- An updated python-mode.el version 4.1 which integrates Ken
2070 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2071 much nicer in XEmacs and Emacs. When stepping through your program
2072 with pdb, in either the shell window or the *Python* window, the
2073 source file and line will be tracked by an arrow. Very cool!
2074
2075- IDLE: syntax warnings in interactive mode are changed into errors.
2076
2077- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002078 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002079
2080- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002081
Barry Warsaw11e89c72001-04-11 20:37:57 +00002082
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002083What's New in Python 2.1 beta 2?
2084================================
2085
Guido van Rossum053ae352001-03-22 14:17:21 +00002086(Unlisted are many fixed bugs, more documentation, etc.)
2087
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002088Core language, builtins, and interpreter
2089
Guido van Rossum053ae352001-03-22 14:17:21 +00002090- The nested scopes work (enabled by "from __future__ import
2091 nested_scopes") is completed; in particular, the future now extends
2092 into code executed through exec, eval() and execfile(), and into the
2093 interactive interpreter.
2094
2095- When calling a base class method (e.g. BaseClass.__init__(self)),
2096 this is now allowed even if self is not strictly spoken a class
2097 instance (e.g. when using metaclasses or the Don Beaudry hook).
2098
2099- Slice objects are now comparable but not hashable; this prevents
2100 dict[:] from being accepted but meaningless.
2101
2102- Complex division is now calculated using less braindead algorithms.
2103 This doesn't change semantics except it's more likely to give useful
2104 results in extreme cases. Complex repr() now uses full precision
2105 like float repr().
2106
2107- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2108
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002109- It is illegal to assign to the name __debug__, which is set when the
2110 interpreter starts. It is effectively a compile-time constant.
2111
2112- A warning will be issued if a global statement for a variable
2113 follows a use or assignment of that variable.
2114
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002115Standard library
2116
Guido van Rossum053ae352001-03-22 14:17:21 +00002117- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2118 inspired by JUnit), is now part of the standard library. You now
2119 have a choice of two testing frameworks: unittest requires you to
2120 write testcases as separate code, doctest gathers them from
2121 docstrings. Both approaches have their advantages and
2122 disadvantages.
2123
2124- A new module Tix was added, which wraps the Tix extension library
2125 for Tk. With that module, it is not necessary to statically link
2126 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2127 require" command. See Demo/tix/.
2128
2129- tzparse.py is now obsolete.
2130
2131- In gzip.py, the seek() and tell() methods are removed -- they were
2132 non-functional anyway, and it's better if callers can test for their
2133 existence with hasattr().
2134
2135Python/C API
2136
2137- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2138 that's already in the dictionary during a PyDict_Next() iteration.
2139 This used to fail occasionally when a dictionary resize operation
2140 could be triggered that would rehash all the keys. All other
2141 modifications to the dictionary are still off-limits during a
2142 PyDict_Next() iteration!
2143
2144- New extended APIs related to passing compiler variables around.
2145
2146- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2147 implement isinstance() and issubclass().
2148
2149- Py_BuildValue() now has a "D" conversion to create a Python complex
2150 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002151
Fred Drake4e262a92001-03-22 18:26:47 +00002152- Extensions types which support weak references must now set the
2153 field allocated for the weak reference machinery to NULL themselves;
2154 this is done to avoid the cost of checking each object for having a
2155 weakly referencable type in PyObject_INIT(), since most types are
2156 not weakly referencable.
2157
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002158- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2159 free variables and cell variables to and from the frame's f_locals.
2160
2161- Variants of several functions defined in pythonrun.h have been added
2162 to support the nested_scopes future statement. The variants all end
2163 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2164 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2165 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002166 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002167
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002168Distutils
2169
2170- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2171 into the release tree.
2172
Tim Peters0e57abf2001-05-02 07:39:38 +00002173- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002174 (an uninstaller, more customization of the installer's display)
2175
2176- from Jack Jansen: added Mac-specific code to generate a dialog for
2177 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002178 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002179 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002180
2181- added 'platforms' and 'keywords' to the set of metadata that can be
2182 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002183
2184- applied patches from Jason Tishler to make the compiler class work with
2185 Cygwin.
2186
2187
Tim Peters2fe289a2001-03-01 22:19:38 +00002188What's New in Python 2.1 beta 1?
2189================================
Tim Petersd66595f2001-02-04 03:09:53 +00002190
2191Core language, builtins, and interpreter
2192
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002193- Following an outcry from the community about the amount of code
2194 broken by the nested scopes feature introduced in 2.1a2, we decided
2195 to make this feature optional, and to wait until Python 2.2 (or at
2196 least 6 months) to make it standard. The option can be enabled on a
2197 per-module basis by adding "from __future__ import nested_scopes" at
2198 the beginning of a module (before any other statements, but after
2199 comments and an optional docstring). See PEP 236 (Back to the
2200 __future__) for a description of the __future__ statement. PEP 227
2201 (Statically Nested Scopes) has been updated to reflect this change,
2202 and to clarify the semantics in a number of endcases.
2203
2204- The nested scopes code, when enabled, has been hardened, and most
2205 bugs and memory leaks in it have been fixed.
2206
2207- Compile-time warnings are now generated for a number of conditions
2208 that will break or change in meaning when nested scopes are enabled:
2209
2210 - Using "from...import *" or "exec" without in-clause in a function
2211 scope that also defines a lambda or nested function with one or
2212 more free (non-local) variables. The presence of the import* or
2213 bare exec makes it impossible for the compiler to determine the
2214 exact set of local variables in the outer scope, which makes it
2215 impossible to determine the bindings for free variables in the
2216 inner scope. To avoid the warning about import *, change it into
2217 an import of explicitly name object, or move the import* statement
2218 to the global scope; to avoid the warning about bare exec, use
2219 exec...in... (a good idea anyway -- there's a possibility that
2220 bare exec will be deprecated in the future).
2221
2222 - Use of a global variable in a nested scope with the same name as a
2223 local variable in a surrounding scope. This will change in
2224 meaning with nested scopes: the name in the inner scope will
2225 reference the variable in the outer scope rather than the global
2226 of the same name. To avoid the warning, either rename the outer
2227 variable, or use a global statement in the inner function.
2228
Neil Schemenauera35c6882001-02-27 04:45:05 +00002229- An optional object allocator has been included. This allocator is
2230 optimized for Python objects and should be faster and use less memory
2231 than the standard system allocator. It is not enabled by default
2232 because of possible thread safety problems. The allocator is only
2233 protected by the Python interpreter lock and it is possible that some
2234 extension modules require a thread safe allocator. The object
2235 allocator can be enabled by providing the "--with-pymalloc" option to
2236 configure.
2237
Tim Petersd66595f2001-02-04 03:09:53 +00002238Standard library
2239
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002240- pyexpat now detects the expat version if expat.h defines it. A
2241 number of additional handlers are provided, which are only available
2242 since expat 1.95. In addition, the methods SetParamEntityParsing and
2243 GetInputContext of Parser objects are available with 1.95.x
2244 only. Parser objects now provide the ordered_attributes and
2245 specified_attributes attributes. A new module expat.model was added,
2246 which offers a number of additional constants if 1.95.x is used.
2247
2248- xml.dom offers the new functions registerDOMImplementation and
2249 getDOMImplementation.
2250
2251- xml.dom.minidom offers a toprettyxml method. A number of DOM
2252 conformance issues have been resolved. In particular, Element now
2253 has an hasAttributes method, and the handling of namespaces was
2254 improved.
2255
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002256- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2257 getting information about live Python code, and pydoc.py, a module
2258 for interactively converting docstrings to HTML or text.
2259 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002260 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002261 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2262 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002263
Tim Peters1eff7962001-03-01 02:31:33 +00002264- New library module difflib.py, primarily packaging the SequenceMatcher
2265 class at the heart of the popular ndiff.py file-comparison tool.
2266
2267- doctest.py (a framework for verifying Python code examples in docstrings)
2268 is now part of the std library.
2269
Tim Petersd66595f2001-02-04 03:09:53 +00002270Windows changes
2271
Guido van Rossume3955a82001-03-02 14:05:59 +00002272- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2273 small GUI that lets you browse the module docstrings using your
2274 default web browser.
2275
Tim Peters1eff7962001-03-01 02:31:33 +00002276- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2277 Platforms) is implemented. See
2278
2279 http://python.sourceforge.net/peps/pep-0235.html
2280
2281 for full details, especially the "Current Lower-Left Semantics" section.
2282 The new Windows import rules are simpler than before:
2283
2284 A. If the PYTHONCASEOK environment variable exists, same as
2285 before: silently accept the first case-insensitive match of any
2286 kind; raise ImportError if none found.
2287
2288 B. Else search sys.path for the first case-sensitive match; raise
2289 ImportError if none found.
2290
2291 The same rules have been implented on other platforms with case-
2292 insensitive but case-preserving filesystems too (including Cygwin, and
2293 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002294
Tim Peters25a9ce32001-02-19 07:06:36 +00002295- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2296 what it's supposed to do (and does do under NT and 2000) via direct
2297 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002298 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002299 all Win9x systems before.
2300
Tim Peters1eff7962001-03-01 02:31:33 +00002301- Build: Subproject _test (effectively) renamed to _testcapi.
2302
Tim Peters2fe289a2001-03-01 22:19:38 +00002303New platforms
2304
2305- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2306 Thanks to Steven Majewski!
2307
2308- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2309 Tishler!
2310
Guido van Rossum9089b272001-03-02 06:49:50 +00002311- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2312 Schwertberger! See RISCOS/README for more information -- it seems
2313 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002314 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002315
Tim Peters25a9ce32001-02-19 07:06:36 +00002316
Tim Petersd7b5e882001-01-25 03:36:26 +00002317What's New in Python 2.1 alpha 2?
2318=================================
Tim Peters40ead762001-01-27 05:35:26 +00002319
Tim Petersd7b5e882001-01-25 03:36:26 +00002320Core language, builtins, and interpreter
2321
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002322- Scopes nest. If a name is used in a function or class, but is not
2323 local, the definition in the nearest enclosing function scope will
2324 be used. One consequence of this change is that lambda statements
2325 could reference variables in the namespaces where the lambda is
2326 defined. In some unusual cases, this change will break code.
2327
2328 In all previous version of Python, names were resolved in exactly
2329 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002330 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002331 function A is defined within a function B, the names bound in B are
2332 not visible in A. The new rules make names bound in B visible in A,
2333 unless A contains a name binding that hides the binding in B.
2334
2335 Section 4.1 of the reference manual describes the new scoping rules
2336 in detail. The test script in Lib/test/test_scope.py demonstrates
2337 some of the effects of the change.
2338
2339 The new rules will cause existing code to break if it defines nested
2340 functions where an outer function has local variables with the same
2341 name as globals or builtins used by the inner function. Example:
2342
2343 def munge(str):
2344 def helper(x):
2345 return str(x)
2346 if type(str) != type(''):
2347 str = helper(str)
2348 return str.strip()
2349
2350 Under the old rules, the name str in helper() is bound to the
2351 builtin function str(). Under the new rules, it will be bound to
2352 the argument named str and an error will occur when helper() is
2353 called.
2354
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002355- The compiler will report a SyntaxError if "from ... import *" occurs
2356 in a function or class scope. The language reference has documented
2357 that this case is illegal, but the compiler never checked for it.
2358 The recent introduction of nested scope makes the meaning of this
2359 form of name binding ambiguous. In a future release, the compiler
2360 may allow this form when there is no possibility of ambiguity.
2361
Tim Peters40ead762001-01-27 05:35:26 +00002362- repr(string) is easier to read, now using hex escapes instead of octal,
2363 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2364
2365 >>> "\texample \r\n" + chr(0) + chr(255)
2366 '\texample \r\n\x00\xff' # in 2.1
2367 '\011example \015\012\000\377' # in 2.0
2368
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002369- Functions are now compared and hashed by identity, not by value, since
2370 the func_code attribute is writable.
2371
Fred Drakefb9d7122001-02-01 20:00:40 +00002372- Weak references (PEP 205) have been added. This involves a few
2373 changes in the core, an extension module (_weakref), and a Python
2374 module (weakref). The weakref module is the public interface. It
2375 includes support for "explicit" weak references, proxy objects, and
2376 mappings with weakly held values.
2377
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002378- A 'continue' statement can now appear in a try block within the body
2379 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002380 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002381
Tim Petersd7b5e882001-01-25 03:36:26 +00002382Standard library
2383
Barry Warsaw30dbd142001-01-31 22:14:01 +00002384- mailbox.py now has a new class, PortableUnixMailbox which is
2385 identical to UnixMailbox but uses a more portable scheme for
2386 determining From_ separators. Also, the constructors for all the
2387 classes in this module have a new optional `factory' argument, which
2388 is a callable used when new message classes must be instantiated by
2389 the next() method.
2390
Tim Petersd7b5e882001-01-25 03:36:26 +00002391- random.py is now self-contained, and offers all the functionality of
2392 the now-deprecated whrandom.py. See the docs for details. random.py
2393 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002394 and restoring the internal state of the generator; and jumpahead(n),
2395 for quickly forcing the internal state to be the same as if n calls to
2396 random() had been made. The latter is particularly useful for multi-
2397 threaded programs, creating one instance of the random.Random() class for
2398 each thread, then using .jumpahead() to force each instance to use a
2399 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002400
Tim Peters0de88fc2001-02-01 04:59:18 +00002401- random.py's seed() function is new. For bit-for-bit compatibility with
2402 prior releases, use the whseed function instead. The new seed function
2403 addresses two problems: (1) The old function couldn't produce more than
2404 about 2**24 distinct internal states; the new one about 2**45 (the best
2405 that can be done in the Wichmann-Hill generator). (2) The old function
2406 sometimes produced identical internal states when passed distinct
2407 integers, and there was no simple way to predict when that would happen;
2408 the new one guarantees to produce distinct internal states for all
2409 arguments in [0, 27814431486576L).
2410
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002411- The socket module now supports raw packets on Linux. The socket
2412 family is AF_PACKET.
2413
Tim Peters9ea17ac2001-02-02 05:57:15 +00002414- test_capi.py is a start at running tests of the Python C API. The tests
2415 are implemented by the new Modules/_testmodule.c.
2416
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002417- A new extension module, _symtable, provides provisional access to the
2418 internal symbol table used by the Python compiler. A higher-level
2419 interface will be added on top of _symtable in a future release.
2420
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002421- Removed the obsolete soundex module.
2422
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002423- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2424 the isSameNode method; NamedNodeMap the get method.
2425
2426- xml.sax.expatreader supports the lexical handler property; it
2427 generates comment, startCDATA, and endCDATA events.
2428
Tim Petersee826f82001-01-31 19:39:44 +00002429Windows changes
2430
2431- Build procedure: the zlib project is built in a different way that
2432 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002433 the zlib binary used. See PCbuild\readme.txt for details. Your old
2434 zlib-related directories can be deleted; you'll need to download fresh
2435 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002436
Tim Peters9ea17ac2001-02-02 05:57:15 +00002437- Build: New subproject _test for the benefit of test_capi.py (see above).
2438
Tim Petersb16c56f2001-02-02 21:24:51 +00002439- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2440 interface to some Python compiler internals).
2441
2442- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002443 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002444
Tim Petersa3a3a032000-11-30 05:22:44 +00002445What's New in Python 2.1 alpha 1?
2446=================================
2447
2448Core language, builtins, and interpreter
2449
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002450- There is a new Unicode companion to the PyObject_Str() API
2451 called PyObject_Unicode(). It behaves in the same way as the
2452 former, but assures that the returned value is an Unicode object
2453 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002454
Guido van Rossumf98eda02001-01-17 15:54:45 +00002455- The comparison operators support "rich comparison overloading" (PEP
2456 207). C extension types can provide a rich comparison function in
2457 the new tp_richcompare slot in the type object. The cmp() function
2458 and the C function PyObject_Compare() first try the new rich
2459 comparison operators before trying the old 3-way comparison. There
2460 is also a new C API PyObject_RichCompare() (which also falls back on
2461 the old 3-way comparison, but does not constrain the outcome of the
2462 rich comparison to a Boolean result).
2463
2464 The rich comparison function takes two objects (at least one of
2465 which is guaranteed to have the type that provided the function) and
2466 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2467 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2468 object, which may be NotImplemented (in which case the tp_compare
2469 slot function is used as a fallback, if defined).
2470
2471 Classes can overload individual comparison operators by defining one
2472 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002473 __ge__. There are no explicit "reflected argument" versions of
2474 these; instead, __lt__ and __gt__ are each other's reflection,
2475 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2476 reflection (similar at the C level). No other implications are
2477 made; in particular, Python does not assume that == is the Boolean
2478 inverse of !=, or that < is the Boolean inverse of >=. This makes
2479 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002480
2481 Classes or types that want to implement (in)equality tests but not
2482 the ordering operators (i.e. unordered types) should implement ==
2483 and !=, and raise an error for the ordering operators.
2484
Guido van Rossuma88479f2001-01-18 14:28:08 +00002485 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002486 Boolean; e.g. a matrix type might want to return a matrix of bits
2487 for A < B, giving elementwise comparisons. Such types should ensure
2488 that any interpretation of their value in a Boolean context raises
2489 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2490 at the C level) to always raise an exception.
2491
Guido van Rossuma88479f2001-01-18 14:28:08 +00002492- Complex numbers use rich comparisons to define == and != but raise
2493 an exception for <, <=, > and >=. Unfortunately, this also means
2494 that cmp() of two complex numbers raises an exception when the two
2495 numbers differ. Since it is not mathematically meaningful to compare
2496 complex numbers except for equality, I hope that this doesn't break
2497 too much code.
2498
Tim Peters3389f192001-02-18 08:48:49 +00002499- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002500 not defined by the language, other than that it's arbitrary but
2501 consistent (see the Reference Manual). An implementation detail changed
2502 in 2.1a1 such that None now compares less than any other object. Code
2503 relying on this new behavior (like code that relied on the previous
2504 behavior) does so at its own risk.
2505
Barry Warsaw573b5412001-01-15 20:43:18 +00002506- Functions and methods now support getting and setting arbitrarily
2507 named attributes (PEP 232). Functions have a new __dict__
2508 (a.k.a. func_dict) which hold the function attributes. Methods get
2509 and set attributes on their underlying im_func. It is a TypeError
2510 to set an attribute on a bound method.
2511
Guido van Rossum051e3352001-01-15 19:11:10 +00002512- The xrange() object implementation has been improved so that
2513 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2514 limitation that in this case len(xrange(sys.maxint)) can't be
2515 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2516 work fine as long as the index i doesn't actually reach 2**31.
2517 (Python uses regular ints for sequence and string indices; fixing
2518 that is much more work.)
2519
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002520- Two changes to from...import:
2521
Guido van Rossumba381232001-02-03 15:06:40 +00002522 1) "from M import X" now works even if (after loading module M)
2523 sys.modules['M'] is not a real module; it's basically a getattr()
2524 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002525
2526 2) "from M import *" now looks for M.__all__ to decide which names to
2527 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2528 filters out names starting with '_' as before. Whether or not
2529 __all__ exists, there's no restriction on the type of M.
2530
Guido van Rossumf61f1662001-01-10 20:13:55 +00002531- File objects have a new method, xreadlines(). This is the fastest
2532 way to iterate over all lines in a file:
2533
2534 for line in file.xreadlines():
2535 ...do something to line...
2536
2537 See the xreadlines module (mentioned below) for how to do this for
2538 other file-like objects.
2539
2540- Even if you don't use file.xreadlines(), you may expect a speedup on
2541 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002542 quite a bit in platform-specific ways: on systems (like Linux) that
2543 support flockfile(), getc_unlocked(), and funlockfile(), those are
2544 used by default. On systems (like Windows) without getc_unlocked(),
2545 a complicated (but still thread-safe) method using fgets() is used by
2546 default.
2547
Tim Petersd52269b2001-01-25 06:23:18 +00002548 You can force use of the fgets() method by #define'ing
2549 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002550 getc_unlocked()).
2551
Tim Petersd52269b2001-01-25 06:23:18 +00002552 You can force fgets() not to be used by #define'ing
2553 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002554 test_bufio.py fails -- and let us know if it does!).
2555
2556- In addition, the fileinput module, while still slower than the other
2557 methods on most platforms, has been sped up too, by using
2558 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002559
2560- Support for run-time warnings has been added, including a new
2561 command line option (-W) to specify the disposition of warnings.
2562 See the description of the warnings module below.
2563
2564- Extensive changes have been made to the coercion code. This mostly
2565 affects extension modules (which can now implement mixed-type
2566 numerical operators without having to use coercion), but
2567 occasionally, in boundary cases the coercion semantics have changed
2568 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002569 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002570 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002571 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002572
Guido van Rossumf98eda02001-01-17 15:54:45 +00002573- In connection with the coercion changes, a new built-in singleton
2574 object, NotImplemented is defined. This can be returned for
2575 operations that wish to indicate they are not implemented for a
2576 particular combination of arguments. From C, this is
2577 Py_NotImplemented.
2578
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002579- The interpreter accepts now bytecode files on the command line even
2580 if they do not have a .pyc or .pyo extension. On Linux, after executing
2581
Martin v. Löwise214baa2001-02-04 22:37:56 +00002582import imp,sys,string
2583magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2584reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2585open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002586
2587 any byte code file can be used as an executable (i.e. as an argument
2588 to execve(2)).
2589
Tim Peters9940b802000-12-01 07:59:35 +00002590- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002591 character. In 1.6 and earlier, they never produced a sign,
2592 and raised an error if the value of the long was too large
2593 to fit in a Python int. In 2.0, they produced a sign if and
2594 only if too large to fit in an int. This was inconsistent
2595 across platforms (because the size of an int varies across
2596 platforms), and inconsistent with hex() and oct(). Example:
2597
2598 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002599 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002600 'ffffffbe' # in 2.0 and before, on 32-bit machines
2601 >>> hex(-0x42L)
2602 '-0x42L' # in all versions of Python
2603
Tim Peters9940b802000-12-01 07:59:35 +00002604 The behavior of %d formats for negative Python longs remains
2605 the same as in 2.0 (although in 1.6 and before, they raised
2606 an error if the long didn't fit in a Python int).
2607
2608 %u formats don't make sense for Python longs, but are allowed
2609 and treated the same as %d in 2.1. In 2.0, a negative long
2610 formatted via %u produced a sign if and only if too large to
2611 fit in an int. In 1.6 and earlier, a negative long formatted
2612 via %u raised an error if it was too big to fit in an int.
2613
Guido van Rossum3661d392000-12-12 22:10:31 +00002614- Dictionary objects have an odd new method, popitem(). This removes
2615 an arbitrary item from the dictionary and returns it (in the form of
2616 a (key, value) pair). This can be useful for algorithms that use a
2617 dictionary as a bag of "to do" items and repeatedly need to pick one
2618 item. Such algorithms normally end up running in quadratic time;
2619 using popitem() they can usually be made to run in linear time.
2620
Tim Peters36cdad12000-12-29 02:06:45 +00002621Standard library
2622
Thomas Woutersfe385252001-01-19 23:16:56 +00002623- In the time module, the time argument to the functions strftime,
2624 localtime, gmtime, asctime and ctime is now optional, defaulting to
2625 the current time (in the local timezone).
2626
Guido van Rossumda91f222001-01-15 16:36:08 +00002627- The ftplib module now defaults to passive mode, which is deemed a
2628 more useful default given that clients are often inside firewalls
2629 these days. Note that this could break if ftplib is used to connect
2630 to a *server* that is inside a firewall, from outside; this is
2631 expected to be a very rare situation. To fix that, you can call
2632 ftp.set_pasv(0).
2633
Martin v. Löwis10a27872001-01-13 09:54:41 +00002634- The module site now treats .pth files not only for path configuration,
2635 but also supports extensions to the initialization code: Lines starting
2636 with import are executed.
2637
Guido van Rossumf61f1662001-01-10 20:13:55 +00002638- There's a new module, warnings, which implements a mechanism for
2639 issuing and filtering warnings. There are some new built-in
2640 exceptions that serve as warning categories, and a new command line
2641 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2642 turns warnings into errors). warnings.warn(message[, category])
2643 issues a warning message; this can also be called from C as
2644 PyErr_Warn(category, message).
2645
2646- A new module xreadlines was added. This exports a single factory
2647 function, xreadlines(). The intention is that this code is the
2648 absolutely fastest way to iterate over all lines in an open
2649 file(-like) object:
2650
2651 import xreadlines
2652 for line in xreadlines.xreadlines(file):
2653 ...do something to line...
2654
2655 This is equivalent to the previous the speed record holder using
2656 file.readlines(sizehint). Note that if file is a real file object
2657 (as opposed to a file-like object), this is equivalent:
2658
2659 for line in file.xreadlines():
2660 ...do something to line...
2661
Tim Peters36cdad12000-12-29 02:06:45 +00002662- The bisect module has new functions bisect_left, insort_left,
2663 bisect_right and insort_right. The old names bisect and insort
2664 are now aliases for bisect_right and insort_right. XXX_right
2665 and XXX_left methods differ in what happens when the new element
2666 compares equal to one or more elements already in the list: the
2667 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002668 right. Code that doesn't care where equal elements end up should
2669 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002670
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002671- The new curses.panel module wraps the panel library that forms part
2672 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2673
Guido van Rossumf61f1662001-01-10 20:13:55 +00002674- The SocketServer module now sets the allow_reuse_address flag by
2675 default in the TCPServer class.
2676
2677- A new function, sys._getframe(), returns the stack frame pointer of
2678 the caller. This is intended only as a building block for
2679 higher-level mechanisms such as string interpolation.
2680
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002681- The pyexpat module supports a number of new handlers, which are
2682 available only in expat 1.2. If invocation of a callback fails, it
2683 will report an additional frame in the traceback. Parser objects
2684 participate now in garbage collection. If expat reports an unknown
2685 encoding, pyexpat will try to use a Python codec; that works only
2686 for single-byte charsets. The parser type objects is exposed as
2687 XMLParserObject.
2688
2689- xml.dom now offers standard definitions for symbolic node type and
2690 exception code constants, and a hierarchy of DOM exceptions. minidom
2691 was adjusted to use them.
2692
2693- The conformance of xml.dom.minidom to the DOM specification was
2694 improved. It detects a number of additional error cases; the
2695 previous/next relationship works even when the tree is modified;
2696 Node supports the normalize() method; NamedNodeMap, DocumentType and
2697 DOMImplementation classes were added; Element supports the
2698 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2699 method.
2700
Guido van Rossumf61f1662001-01-10 20:13:55 +00002701Build issues
2702
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002703- For Unix (and Unix-compatible) builds, configuration and building of
2704 extension modules is now greatly automated. Rather than having to
2705 edit the Modules/Setup file to indicate which modules should be
2706 built and where their include files and libraries are, a
2707 distutils-based setup.py script now takes care of building most
2708 extension modules. All extension modules built this way are built
2709 as shared libraries. Only a few modules that must be linked
2710 statically are still listed in the Setup file; you won't need to
2711 edit their configuration.
2712
2713- Python should now build out of the box on Cygwin. If it doesn't,
2714 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002715
2716- Python now always uses its own (renamed) implementation of getopt()
2717 -- there's too much variation among C library getopt()
2718 implementations.
2719
2720- C++ compilers are better supported; the CXX macro is always set to a
2721 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002722
Tim Petersd92dfe02000-12-12 01:18:41 +00002723Windows changes
2724
2725- select module: By default under Windows, a select() call
2726 can specify no more than 64 sockets. Python now boosts
2727 this Microsoft default to 512. If you need even more than
2728 that, see the MS docs (you'll need to #define FD_SETSIZE
2729 and recompile Python from source).
2730
Guido van Rossumf61f1662001-01-10 20:13:55 +00002731- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2732 subdirectory is no more!
2733
Tim Petersa3a3a032000-11-30 05:22:44 +00002734
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002735What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002736=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002737
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002738Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002739changes are in the file HISTORY. If you are making the jump directly
2740from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2741HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002742
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002743Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2744the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2745http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002746
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002747--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002748
2749======================================================================
2750
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002751What's new in 2.0 (since release candidate 1)?
2752==============================================
2753
2754Standard library
2755
2756- The copy_reg module was modified to clarify its intended use: to
2757 register pickle support for extension types, not for classes.
2758 pickle() will raise a TypeError if it is passed a class.
2759
2760- Fixed a bug in gettext's "normalize and expand" code that prevented
2761 it from finding an existing .mo file.
2762
2763- Restored support for HTTP/0.9 servers in httplib.
2764
Tim Peters989b7b92000-10-16 20:24:53 +00002765- The math module was changed to stop raising OverflowError in case of
2766 underflow, and return 0 instead in underflow cases. Whether Python
2767 used to raise OverflowError in case of underflow was platform-
2768 dependent (it did when the platform math library set errno to ERANGE
2769 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002770
2771- Fixed a bug in StringIO that occurred when the file position was not
2772 at the end of the file and write() was called with enough data to
2773 extend past the end of the file.
2774
2775- Fixed a bug that caused Tkinter error messages to get lost on
2776 Windows. The bug was fixed by replacing direct use of
2777 interp->result with Tcl_GetStringResult(interp).
2778
2779- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2780 redirect response.
2781
2782- Several changes were made to distutils: Some debugging code was
2783 removed from util. Fixed the installer used when an external zip
2784 program (like WinZip) is not found; the source code for this
2785 installer is in Misc/distutils. check_lib() was modified to behave
2786 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2787 test for whether installed modules are on sys.path was changed to
2788 use both normcase() and normpath().
2789
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002790- Several minor bugs were fixed in the xml package (the minidom,
2791 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002792
2793- The regression test driver (regrtest.py) behavior when invoked with
2794 -l changed: It now reports a count of objects that are recognized as
2795 garbage but not freed by the garbage collector.
2796
Tim Peters989b7b92000-10-16 20:24:53 +00002797- The regression test for the math module was changed to test
2798 exceptional behavior when the test is run in verbose mode. Python
2799 cannot yet guarantee consistent exception behavior across platforms,
2800 so the exception part of test_math is run only in verbose mode, and
2801 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002802
2803Internals
2804
2805- PyOS_CheckStack() has been disabled on Win64, where it caused
2806 test_sre to fail.
2807
2808Build issues
2809
2810- Changed compiler flags, so that gcc is always invoked with -Wall and
2811 -Wstrict-prototypes. Users compiling Python with GCC should see
2812 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002813 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002814 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002815
Tim Petersa3a3a032000-11-30 05:22:44 +00002816- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002817
2818Tools and other miscellany
2819
2820- The compiler in Tools/compiler was updated to support the new
2821 language features introduced in 2.0: extended print statement, list
2822 comprehensions, and augmented assignments. The new compiler should
2823 also be backwards compatible with Python 1.5.2; the compiler will
2824 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002825 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002826
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002827What's new in 2.0 release candidate 1 (since beta 2)?
2828=====================================================
2829
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002830What is release candidate 1?
2831
2832We believe that release candidate 1 will fix all known bugs that we
2833intend to fix for the 2.0 final release. This release should be a bit
2834more stable than the previous betas. We would like to see even more
2835widespread testing before the final release, so we are producing this
2836release candidate. The final release will be exactly the same unless
2837any show-stopping (or brown bag) bugs are found by testers of the
2838release candidate.
2839
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002840All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002841to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002842
2843Core language, builtins, and interpreter
2844
2845- A bug that caused crashes when __coerce__ was used with augmented
2846 assignment, e.g. +=, was fixed.
2847
2848- Raise ZeroDivisionError when raising zero to a negative number,
2849 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2850 power operator and the result of math.pow(0.0, -2.0) will vary by
2851 platform. On Linux, it raises a ValueError.
2852
2853- A bug in Unicode string interpolation was fixed that occasionally
2854 caused errors with formats including "%%". For example, the
2855 following expression "%% %s" % u"abc" no longer raises a TypeError.
2856
2857- Compilation of deeply nested expressions raises MemoryError instead
2858 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2859
2860- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2861 rendering them useless. They are now written in binary mode again.
2862
2863Standard library
2864
2865- Keyword arguments are now accepted for most pattern and match object
2866 methods in SRE, the standard regular expression engine.
2867
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002868- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002869 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002870
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002871- Several bugs in the Unicode handling and error handling in _tkinter
2872 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002873
2874- Fix memory management errors in Merge() and Tkapp_Call() routines.
2875
2876- Several changes were made to cStringIO to make it compatible with
2877 the file-like object interface and with StringIO. If operations are
2878 performed on a closed object, an exception is raised. The truncate
2879 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002880 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002881
2882- There were many changes made to the linuxaudiodev module and its
2883 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002884 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002885
2886 Note that this module is named poorly, because it should work
2887 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002888 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002889
2890 The module now raises exceptions when errors occur instead of
2891 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2892 audio) and defines a getptr() method that calls the
2893 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2894
2895- The library_version attribute, introduced in an earlier beta, was
2896 removed because it can not be supported with early versions of the C
2897 readline library, which provides no way to determine the version at
2898 compile-time.
2899
2900- The binascii module is now enabled on Win64.
2901
Tim Peters46446d62000-10-09 21:19:31 +00002902- tokenize.py no longer suffers "recursion depth" errors when parsing
2903 programs with very long string literals.
2904
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002905Internals
2906
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002907- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002908 which is called when the interpreter starts up to determine where
2909 the standard library is installed. These vulnerabilities affect all
2910 previous versions of Python and can be exploited by setting very
2911 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2912 setuid Python script, although use of the wrapper in
2913 Misc/setuid-prog.c will eliminate the vulnerability.
2914
2915- Fixed garbage collection bugs in instance creation that were
2916 triggered when errors occurred during initialization. The solution,
2917 applied in cPickle and in PyInstance_New(), is to call
2918 PyObject_GC_Init() after the initialization of the object's
2919 container attributes is complete.
2920
2921- pyexpat adds definitions of PyModule_AddStringConstant and
2922 PyModule_AddObject if the Python version is less than 2.0, which
2923 provides compatibility with PyXML on Python 1.5.2.
2924
2925- If the platform has a bogus definition for LONG_BIT (the number of
2926 bits in a long), an error will be reported at compile time.
2927
2928- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2929 collection crashes and possibly other, unreported crashes.
2930
2931- Fixed a memory leak in _PyUnicode_Fini().
2932
2933Build issues
2934
2935- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002936 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002937 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002938
2939- The mmap.PAGESIZE constant is now initialized using sysconf when
2940 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2941
2942- The md5 file should now compile on all platforms.
2943
2944- The select module now compiles on platforms that do not define
2945 POLLRDNORM and related constants.
2946
2947- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002948 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002949
Jeremy Hylton10921202000-10-09 18:34:12 +00002950- BeOS: A number of changes were made to the build and installation
2951 process. ar-fake now operates on a directory of object files.
2952 dl_export.h is gone, and its macros now appear on the mwcc command
2953 line during build on PPC BeOS.
2954
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002955- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002956 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002957
2958- Cygwin: Support for shared libraries, Tkinter, and sockets.
2959
2960- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2961
2962Tools and other miscellany
2963
2964- Removed debugging prints from main used with freeze.
2965
Tim Peters46446d62000-10-09 21:19:31 +00002966- IDLE auto-indent no longer crashes when it encounters Unicode
2967 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002968
2969What's new in 2.0 beta 2 (since beta 1)?
2970========================================
2971
2972Core language, builtins, and interpreter
2973
Tim Peters482c0212000-09-26 06:33:09 +00002974- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002975 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002976
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002977- Add -h and -V command line options to print the usage message and
2978 Python version number and exit immediately.
2979
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002980- eval() and exec accept Unicode objects as code parameters.
2981
2982- getattr() and setattr() now also accept Unicode objects for the
2983 attribute name, which are converted to strings using the default
2984 encoding before lookup.
2985
2986- Multiplication on string and Unicode now does proper bounds
2987 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2988 string is too long."
2989
2990- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002991 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002992
Jeremy Hylton1b618592000-09-26 05:32:36 +00002993
2994Standard library and extensions
2995
Guido van Rossum5b08f132001-04-16 02:05:23 +00002996- socket module: the OpenSSL code now adds support for RAND_status()
2997 and EGD (Entropy Gathering Device).
2998
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002999- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00003000 argument checking; it still takes no arguments.
3001
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003002- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003003
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003004- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003005
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003006- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003007
3008- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003009 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003010
3011- copy: Copy Unicode objects atomically.
3012
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003013- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003014
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003015- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003016
Fred Drake67233bc2000-09-26 16:40:27 +00003017- dbm: Add get() and setdefault() methods to dbm object. Add constant
3018 `library' to module that names the library used. Added doc strings
3019 and method names to error messages. Uses configure to determine
3020 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
3021 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003022
3023- distutils: Update to version 0.9.3.
3024
3025- dl: Add several dl.RTLD_ constants.
3026
3027- fpectl: Now supported on FreeBSD.
3028
3029- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
3030 found by the collector will be saved in gc.garbage. This is useful
3031 for debugging a program that creates reference cycles.
3032
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003033- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003034 of HTTP class. Do not close socket on zero-length response. Do not
3035 crash when server sends invalid content-length header.
3036
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003037- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003038
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003039- marshal: When reading a short, sign-extend on platforms where shorts
3040 are bigger than 16 bits. When reading a long, repair the unportable
3041 sign extension that was being done for 64-bit machines. (It assumed
3042 that signed right shift sign-extends.)
3043
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003044- operator: Add contains(), invert(), __invert__() as aliases for
3045 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003046
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003047- os: Add support for popen2() and popen3() on all platforms where
3048 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003049
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003050- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003051 clicking on a file in Explorer (or passing the file name to the
3052 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003053
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003054- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003055 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003056
3057- pickle: Now raises ValueError when an invalid pickle that contains
3058 a non-string repr where a string repr was expected. This behavior
3059 matches cPickle.
3060
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003061- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003062
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003063- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003064
3065- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003066 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003067 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003068
3069- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003070 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003071
3072- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003073 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003074 few cycles during startup since the first call to
3075 setdefaultencoding() will initialize the codec registry and the
3076 encodings package.
3077
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003078- socket: Support for size hint in readlines() method of object returned
3079 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003080
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003081- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003082 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003083 is followed by whitespace.
3084
Tim Petersa3a3a032000-11-30 05:22:44 +00003085- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003086
3087- struct: Check ranges for bytes and shorts.
3088
3089- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003090 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003091
3092- Tkinter: Image objects are now guaranteed to have unique ids. Set
3093 event.delta to zero if Tk version doesn't support mousewheel.
3094 Removed some debugging prints.
3095
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003096- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003097
Fred Drake67233bc2000-09-26 16:40:27 +00003098- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003099 which works around a bug in Norton AntiVirus 2000 that leads directly
3100 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003101
3102- xml: New version detection code allows PyXML to override standard
3103 XML package if PyXML version is greater than 0.6.1.
3104
Fred Drake64bb3802000-09-26 16:21:35 +00003105- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3106 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3107 tree only for nodes which are sufficiently interesting to a specific
3108 application. Does not provide the HTML-specific extensions. Still
3109 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003110
Fred Drake64bb3802000-09-26 16:21:35 +00003111- xml.sax: SAX 2 support for Python, including all the handler
3112 interfaces needed to process XML 1.0 compliant XML. Some
3113 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003114
Fred Drake64bb3802000-09-26 16:21:35 +00003115- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3116 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003117
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003118
Jeremy Hylton1b618592000-09-26 05:32:36 +00003119C API
3120
3121- Add three new convenience functions for module initialization --
3122 PyModule_AddObject(), PyModule_AddIntConstant(), and
3123 PyModule_AddStringConstant().
3124
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003125- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003126 removed and add #error to Python.h if NULL isn't defined after
3127 #include of stdio.h.
3128
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003129- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003130 backwards compatibility (at the source level) with old extensions.
3131
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003132- A wrapper API was added for signal() and sigaction(). Instead of
3133 either function, always use PyOS_getsig() to get a signal handler
3134 and PyOS_setsig() to set one. A new convenience typedef
3135 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003136
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003137- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003138 internal data buffer and size of a string object -- or the default
3139 encoded version of a Unicode object.
3140
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003141- PyString_Size() and PyString_AsString() accept Unicode objects.
3142
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003143- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003144 exists). INT_MAX and LONG_MAX will always be defined, even if
3145 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003146
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003147- PyFloat_FromString takes a second argument, pend, that was
3148 effectively useless. It is now officially useless but preserved for
3149 backwards compatibility. If the pend argument is not NULL, *pend is
3150 set to NULL.
3151
3152- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3153 for the attribute name. See note on getattr() above.
3154
3155- A few bug fixes to argument processing for Unicode.
3156 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3157 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3158 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003159 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003160
3161- Py_BuildValue accepts B format (for bgen-generated code).
3162
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003163
Jeremy Hylton1b618592000-09-26 05:32:36 +00003164Internals
3165
3166- On Unix, fix code for finding Python installation directory so that
3167 it works when argv[0] is a relative path.
3168
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003169- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003170 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003171 rather than by generating a copy of the object.
3172
Tim Peters482c0212000-09-26 06:33:09 +00003173- Several of the internal Unicode tables are much smaller now, and
3174 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003175
Jeremy Hylton97693b02000-09-26 17:42:51 +00003176- In the garbage collector: Fixed bug in collection of tuples. Fixed
3177 bug that caused some instances to be removed from the container set
3178 while they were still live. Fixed parsing in gc.set_debug() for
3179 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003180
3181- Fixed refcount problem in instance deallocation that only occurred
3182 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3183
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003184- On Windows, getpythonregpath is now protected against null data in
3185 registry key.
3186
3187- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003188 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003189
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003190
Jeremy Hylton1b618592000-09-26 05:32:36 +00003191Build and platform-specific issues
3192
3193- Better support of GNU Pth via --with-pth configure option.
3194
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003195- Python/C API now properly exposed to dynamically-loaded extension
3196 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003197
3198- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3199 Don't define MS_SYNC to be zero when it is undefined. Added missing
3200 prototypes in posixmodule.c.
3201
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003202- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003203 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003204
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003205- Fix largefile support on older NetBSD systems and OpenBSD by adding
3206 define for TELL64.
3207
3208
3209Tools and other miscellany
3210
3211- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3212
3213- freeze: The modulefinder now works with 2.0 opcodes.
3214
Tim Petersa3a3a032000-11-30 05:22:44 +00003215- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003216 Move hackery of sys.argv until after the Tk instance has been
3217 created, which allows the application-specific Tkinter
3218 initialization to be executed if present; also pass an explicit
3219 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003220
Jeremy Hylton1b618592000-09-26 05:32:36 +00003221
3222What's new in 2.0 beta 1?
3223=========================
3224
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003225Source Incompatibilities
3226------------------------
3227
3228None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3229such as single-argument append(), connect() and bind(), and changes to
3230str(long) and repr(float).
3231
3232
3233Binary Incompatibilities
3234------------------------
3235
3236- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3237with Python 2.0; these extensions will have to be rebuilt for Python
32382.0.
3239
3240- On Windows, attempting to import a third party extension built for
3241Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3242can do about this. Check your PYTHONPATH environment variable!
3243
3244- Python bytecode files (*.pyc and *.pyo) are not compatible between
3245releases.
3246
3247
3248Overview of Changes Since 1.6
3249-----------------------------
3250
3251There are many new modules (including brand new XML support through
3252the xml package, and i18n support through the gettext module); a list
3253of all new modules is included below. Lots of bugs have been fixed.
3254
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003255The process for making major new changes to the language has changed
3256since Python 1.6. Enhancements must now be documented by a Python
3257Enhancement Proposal (PEP) before they can be accepted.
3258
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003259There are several important syntax enhancements, described in more
3260detail below:
3261
3262 - Augmented assignment, e.g. x += 1
3263
3264 - List comprehensions, e.g. [x**2 for x in range(10)]
3265
3266 - Extended import statement, e.g. import Module as Name
3267
3268 - Extended print statement, e.g. print >> file, "Hello"
3269
3270Other important changes:
3271
3272 - Optional collection of cyclical garbage
3273
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003274Python Enhancement Proposal (PEP)
3275---------------------------------
3276
3277PEP stands for Python Enhancement Proposal. A PEP is a design
3278document providing information to the Python community, or describing
3279a new feature for Python. The PEP should provide a concise technical
3280specification of the feature and a rationale for the feature.
3281
3282We intend PEPs to be the primary mechanisms for proposing new
3283features, for collecting community input on an issue, and for
3284documenting the design decisions that have gone into Python. The PEP
3285author is responsible for building consensus within the community and
3286documenting dissenting opinions.
3287
3288The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003289
3290Augmented Assignment
3291--------------------
3292
3293This must have been the most-requested feature of the past years!
3294Eleven new assignment operators were added:
3295
Guido van Rossume905e952000-09-05 12:42:46 +00003296 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003297
3298For example,
3299
3300 A += B
3301
3302is similar to
3303
3304 A = A + B
3305
3306except that A is evaluated only once (relevant when A is something
3307like dict[index].attr).
3308
3309However, if A is a mutable object, A may be modified in place. Thus,
3310if A is a number or a string, A += B has the same effect as A = A+B
3311(except A is only evaluated once); but if a is a list, A += B has the
3312same effect as A.extend(B)!
3313
3314Classes and built-in object types can override the new operators in
3315order to implement the in-place behavior; the not-in-place behavior is
3316used automatically as a fallback when an object doesn't implement the
3317in-place behavior. For classes, the method name is derived from the
3318method name for the corresponding not-in-place operator by inserting
3319an 'i' in front of the name, e.g. __iadd__ implements in-place
3320__add__.
3321
3322Augmented assignment was implemented by Thomas Wouters.
3323
3324
3325List Comprehensions
3326-------------------
3327
3328This is a flexible new notation for lists whose elements are computed
3329from another list (or lists). The simplest form is:
3330
3331 [<expression> for <variable> in <sequence>]
3332
Guido van Rossum56db0952000-09-06 23:34:25 +00003333For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003334This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003335
3336You can also add a condition:
3337
3338 [<expression> for <variable> in <sequence> if <condition>]
3339
3340For example, [w for w in words if w == w.lower()] would yield the list
3341of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003342than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003343
3344You can also have nested for loops and more than one 'if' clause. For
3345example, here's a function that flattens a sequence of sequences::
3346
3347 def flatten(seq):
3348 return [x for subseq in seq for x in subseq]
3349
3350 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3351
3352This prints
3353
3354 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3355
3356List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003357Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003358
3359
3360Extended Import Statement
3361-------------------------
3362
3363Many people have asked for a way to import a module under a different
3364name. This can be accomplished like this:
3365
3366 import foo
3367 bar = foo
3368 del foo
3369
3370but this common idiom gets old quickly. A simple extension of the
3371import statement now allows this to be written as follows:
3372
3373 import foo as bar
3374
3375There's also a variant for 'from ... import':
3376
3377 from foo import bar as spam
3378
3379This also works with packages; e.g. you can write this:
3380
3381 import test.regrtest as regrtest
3382
3383Note that 'as' is not a new keyword -- it is recognized only in this
3384context (this is only possible because the syntax for the import
3385statement doesn't involve expressions).
3386
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003387Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003388
3389
3390Extended Print Statement
3391------------------------
3392
3393Easily the most controversial new feature, this extension to the print
3394statement adds an option to make the output go to a different file
3395than the default sys.stdout.
3396
3397For example, to write an error message to sys.stderr, you can now
3398write:
3399
3400 print >> sys.stderr, "Error: bad dog!"
3401
3402As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003403evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003404
3405 print >> None, "Hello world"
3406
3407is equivalent to
3408
3409 print "Hello world"
3410
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003411Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003412
3413
3414Optional Collection of Cyclical Garbage
3415---------------------------------------
3416
3417Python is now equipped with a garbage collector that can hunt down
3418cyclical references between Python objects. It's no replacement for
3419reference counting; in fact, it depends on the reference counts being
3420correct, and decides that a set of objects belong to a cycle if all
3421their reference counts can be accounted for from their references to
3422each other. This devious scheme was first proposed by Eric Tiedemann,
3423and brought to implementation by Neil Schemenauer.
3424
3425There's a module "gc" that lets you control some parameters of the
3426garbage collection. There's also an option to the configure script
3427that lets you enable or disable the garbage collection. In 2.0b1,
3428it's on by default, so that we (hopefully) can collect decent user
3429experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003430performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003431off by default in the final 2.0 release.
3432
3433
3434Smaller Changes
3435---------------
3436
3437A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3438map(None, seq1, seq2, ...) when the sequences have the same length;
3439i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3440the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003441zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003442
3443sys.version_info is a tuple (major, minor, micro, level, serial).
3444
3445Dictionaries have an odd new method, setdefault(key, default).
3446dict.setdefault(key, default) returns dict[key] if it exists; if not,
3447it sets dict[key] to default and returns that value. Thus:
3448
3449 dict.setdefault(key, []).append(item)
3450
3451does the same work as this common idiom:
3452
3453 if not dict.has_key(key):
3454 dict[key] = []
3455 dict[key].append(item)
3456
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003457There are two new variants of SyntaxError that are raised for
3458indentation-related errors: IndentationError and TabError.
3459
3460Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3461escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003462
3463The limits on the size of expressions and file in Python source code
3464have been raised from 2**16 to 2**32. Previous versions of Python
3465were limited because the maximum argument size the Python VM accepted
3466was 2**16. This limited the size of object constructor expressions,
3467e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3468limit was raised thanks to a patch by Charles Waldman that effectively
3469fixes the problem. It is now much more likely that you will be
3470limited by available memory than by an arbitrary limit in Python.
3471
3472The interpreter's maximum recursion depth can be modified by Python
3473programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3474limit is the maximum number of recursive calls that can be made by
3475Python code. The limit exists to prevent infinite recursion from
3476overflowing the C stack and causing a core dump. The default value is
34771000. The maximum safe value for a particular platform can be found
3478by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003479
3480New Modules and Packages
3481------------------------
3482
3483atexit - for registering functions to be called when Python exits.
3484
3485imputil - Greg Stein's alternative API for writing custom import
3486hooks.
3487
3488pyexpat - an interface to the Expat XML parser, contributed by Paul
3489Prescod.
3490
3491xml - a new package with XML support code organized (so far) in three
3492subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3493would fill a volume. There's a special feature whereby a
3494user-installed package named _xmlplus overrides the standard
3495xmlpackage; this is intended to give the XML SIG a hook to distribute
3496backwards-compatible updates to the standard xml package.
3497
3498webbrowser - a platform-independent API to launch a web browser.
3499
3500
Guido van Rossume905e952000-09-05 12:42:46 +00003501Changed Modules
3502---------------
3503
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003504array -- new methods for array objects: count, extend, index, pop, and
3505remove
3506
3507binascii -- new functions b2a_hex and a2b_hex that convert between
3508binary data and its hex representation
3509
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003510calendar -- Many new functions that support features including control
3511over which day of the week is the first day, returning strings instead
3512of printing them. Also new symbolic constants for days of week,
3513e.g. MONDAY, ..., SUNDAY.
3514
3515cgi -- FieldStorage objects have a getvalue method that works like a
3516dictionary's get method and returns the value attribute of the object.
3517
3518ConfigParser -- The parser object has new methods has_option,
3519remove_section, remove_option, set, and write. They allow the module
3520to be used for writing config files as well as reading them.
3521
3522ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003523optionally support the RFC 959 REST command.
3524
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003525gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003526
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003527httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3528the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003529
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003530locale -- implement getdefaultlocale for Win32 and Macintosh
3531
3532marshal -- no longer dumps core when marshaling deeply nested or
3533recursive data structures
3534
3535os -- new functions isatty, seteuid, setegid, setreuid, setregid
3536
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003537os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3538support under Unix.
3539
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003540os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003541
3542os.path -- fix semantics of os.path.commonprefix
3543
3544smtplib -- support for sending very long messages
3545
3546socket -- new function getfqdn()
3547
3548readline -- new functions to read, write and truncate history files.
3549The readline section of the library reference manual contains an
3550example.
3551
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003552select -- add interface to poll system call
3553
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003554shutil -- new copyfileobj function
3555
3556SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3557HTTP server.
3558
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003559Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003560
3561urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003562e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003563
3564whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003565
3566
3567Obsolete Modules
3568----------------
3569
3570None. However note that 1.6 made a whole slew of modules obsolete:
3571stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3572poly, zmod, strop, util, whatsound.
3573
3574
3575Changed, New, Obsolete Tools
3576----------------------------
3577
Tim Peters8b092332000-09-05 20:15:25 +00003578None.
Guido van Rossume905e952000-09-05 12:42:46 +00003579
3580
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003581C-level Changes
3582---------------
3583
3584Several cleanup jobs were carried out throughout the source code.
3585
3586All C code was converted to ANSI C; we got rid of all uses of the
3587Py_PROTO() macro, which makes the header files a lot more readable.
3588
3589Most of the portability hacks were moved to a new header file,
3590pyport.h; several other new header files were added and some old
3591header files were removed, in an attempt to create a more rational set
3592of header files. (Few of these ever need to be included explicitly;
3593they are all included by Python.h.)
3594
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003595Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003596and Win64, especially for the new Intel Itanium processor. Mick also
3597added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003598
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003599The C APIs to return an object's size have been update to consistently
3600use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3601previous versions, the abstract interfaces used PyXXX_Length and the
3602concrete interfaces used PyXXX_Size. The old names,
3603e.g. PyObject_Length, are still available for backwards compatibility
3604at the API level, but are deprecated.
3605
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003606The PyOS_CheckStack function has been implemented on Windows by
3607Fredrik Lundh. It prevents Python from failing with a stack overflow
3608on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003609
3610The GC changes resulted in creation of two new slots on object,
3611tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003612the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003613
3614The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003615C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003616
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003617PyErr_Format has been updated to automatically calculate the size of
3618the buffer needed to hold the formatted result string. This change
3619prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003620
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003621New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003622
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003623PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3624that are the same as their non-Ex counterparts except they take an
3625extra flag argument that tells them to close the file when done.
3626
3627XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003628
Tim Peters8b092332000-09-05 20:15:25 +00003629
3630Windows Changes
3631---------------
3632
3633New popen2/popen3/peopen4 in os module (see Changed Modules above).
3634
3635os.popen is much more usable on Windows 95 and 98. See Microsoft
3636Knowledge Base article Q150956. The Win9x workaround described there
3637is implemented by the new w9xpopen.exe helper in the root of your
3638Python installation. Note that Python uses this internally; it is not
3639a standalone program.
3640
3641Administrator privileges are no longer required to install Python
3642on Windows NT or Windows 2000. If you have administrator privileges,
3643Python's registry info will be written under HKEY_LOCAL_MACHINE.
3644Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003645under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003646uses of Python, but will prevent some advanced uses from working
3647(for example, running a Python script as an NT service, or possibly
3648from CGI).
3649
3650[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3651installer; instead, it installs the needed Tcl/Tk files directly in the
3652Python directory. If you already have a Tcl/Tk installation, this
3653wastes some disk space (about 4 Megs) but avoids problems with
3654conflicting Tcl/Tk installations, and makes it much easier for Python
3655to ensure that Tcl/Tk can find all its files.
3656
3657[This was new in 1.6] The Windows installer now installs by default in
3658\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3659
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003660
3661Updates to the changes between 1.5.2 and 1.6
3662--------------------------------------------
3663
3664The 1.6 NEWS file can't be changed after the release is done, so here
3665is some late-breaking news:
3666
3667New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3668and changes to getlocale() and setlocale().
3669
3670The new module is now enabled per default.
3671
3672It is not true that the encodings codecs cannot be used for normal
3673strings: the string.encode() (which is also present on 8-bit strings
3674!) allows using them for 8-bit strings too, e.g. to convert files from
3675cp1252 (Windows) to latin-1 or vice-versa.
3676
3677Japanese codecs are available from Tamito KAJIYAMA:
3678http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3679
3680
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003681======================================================================