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Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001+++++++++++
2Python News
3+++++++++++
4
Skip Montanaro4a385832002-09-20 17:08:52 +00005(editors: check NEWS.help for information about editing NEWS using ReST.)
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Tim Petersaf8446f2001-12-21 21:36:50 +00007What's New in Python 2.3 alpha 1?
Tim Petersaf8446f2001-12-21 21:36:50 +00008=================================
9
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +000010*XXX Release date: DD-MMM-2002 XXX*
11
Tim Petersaf8446f2001-12-21 21:36:50 +000012Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +000013--------------------------------------------
Tim Petersaf8446f2001-12-21 21:36:50 +000014
Guido van Rossume3438782002-08-12 03:42:03 +000015- Assignment to __class__ is disallowed if either the old and the new
16 class is a statically allocated type object (such as defined by an
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +000017 extension module). This prevents anomalies like 2.__class__ = bool.
Guido van Rossume3438782002-08-12 03:42:03 +000018
19- New-style object creation and deallocation have been sped up
20 significantly; they are now faster than classic instance creation
21 and deallocation.
22
23- The __slots__ variable can now mention "private" names, and the
24 right thing will happen (e.g. __slots__ = ["__foo"]).
25
26- The built-ins slice() and buffer() are now callable types. The
27 types classobj (formerly class), code, function, instance, and
28 instancemethod (formerly instance-method), which have no built-in
29 names but are accessible through the types module, are now also
30 callable. The type dict-proxy is renamed to dictproxy.
31
32- Cycles going through the __class__ link of a new-style instance are
33 now detected by the garbage collector.
34
35- Classes using __slots__ are now properly garbage collected.
36 [SF bug 519621]
37
38- Tightened the __slots__ rules: a slot name must be a valid Python
39 identifier.
40
41- The constructor for the module type now requires a name argument and
42 takes an optional docstring argument. Previously, this constructor
43 ignored its arguments. As a consequence, deriving a class from a
44 module (not from the module type) is now illegal; previously this
45 created an unnamed module, just like invoking the module type did.
46 [SF bug 563060]
47
48- A new type object, 'basestring', is added. This is a common base type
49 for 'str' and 'unicode', and can be used instead of
50 types.StringTypes, e.g. to test whether something is "a string":
51 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
52 is an abstract base class and cannot be instantiated directly.
53
54- Changed new-style class instantiation so that when C's __new__
55 method returns something that's not a C instance, its __init__ is
56 not called. [SF bug #537450]
57
58- Fixed super() to work correctly with class methods. [SF bug #535444]
59
60- If you try to pickle an instance of a class that has __slots__ but
61 doesn't define or override __getstate__, a TypeError is now raised.
62 This is done by adding a bozo __getstate__ to the class that always
63 raises TypeError. (Before, this would appear to be pickled, but the
64 state of the slots would be lost.)
65
Tim Petersaf8446f2001-12-21 21:36:50 +000066Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +000067-----------------
Tim Petersaf8446f2001-12-21 21:36:50 +000068
Martin v. Löwisa844f2d2002-10-05 09:46:48 +000069- Unicode file name processing for Windows (PEP 277) is implemented.
Mark Hammond8696ebc2002-10-08 02:44:31 +000070 All platforms now have an os.path.supports_unicode_filenames attribute,
71 which is set to True on Windows NT/2000/XP, and False elsewhere.
Martin v. Löwisa844f2d2002-10-05 09:46:48 +000072
Walter Dörwald3aeb6322002-09-02 13:14:32 +000073- Codec error handling callbacks (PEP 293) are implemented.
74 Error handling in unicode.encode or str.decode can now be customized.
75
Guido van Rossum45ec02a2002-08-19 21:43:18 +000076- A subtle change to the semantics of the built-in function intern():
77 interned strings are no longer immortal. You must keep a reference
78 to the return value intern() around to get the benefit.
79
Guido van Rossumf808b892002-08-16 03:38:10 +000080- Use of 'None' as a variable, argument or attribute name now
81 issues a SyntaxWarning. In the future, None may become a keyword.
82
Michael W. Hudsondd32a912002-08-15 14:59:02 +000083- SET_LINENO is gone. co_lnotab is now consulted to determine when to
84 call the trace function. C code that accessed f_lineno should call
85 PyCode_Addr2Line instead (f_lineno is still there, but not kept up
86 to date).
87
Guido van Rossum9be89462002-08-14 16:11:30 +000088- There's a new warning category, FutureWarning. This is used to warn
89 about a number of situations where the value or sign of an integer
90 result will change in Python 2.4 as a result of PEP 237 (integer
91 unification). The warnings implement stage B0 mentioned in that
92 PEP. The warnings are about the following situations:
93
94 - Octal and hex literals without 'L' prefix in the inclusive range
95 [0x80000000..0xffffffff]; these are currently negative ints, but
96 in Python 2.4 they will be positive longs with the same bit
97 pattern.
98
99 - Left shifts on integer values that cause the outcome to lose
100 bits or have a different sign than the left operand. To be
101 precise: x<<n where this currently doesn't yield the same value
102 as long(x)<<n; in Python 2.4, the outcome will be long(x)<<n.
103
104 - Conversions from ints to string that show negative values as
105 unsigned ints in the inclusive range [0x80000000..0xffffffff];
106 this affects the functions hex() and oct(), and the string
107 formatting codes %u, %o, %x, and %X. In Python 2.4, these will
108 show signed values (e.g. hex(-1) currently returns "0xffffffff";
109 in Python 2.4 it will return "-0x1").
110
Skip Montanaro979c74b2002-09-03 21:25:14 +0000111 - The bits manipulated under the cover by sys.setcheckinterval() have
112 been changed. Both the check interval and the ticker used to be
113 per-thread values. They are now just a pair of global variables. In
114 addition, the default check interval was boosted from 10 to 100
Neal Norwitz7165af22002-09-05 21:42:24 +0000115 bytecode instructions. This may have some effect on systems that
116 relied on the old default value. In particular, in multi-threaded
117 applications which try to be highly responsive, response time will
118 increase by some (perhaps imperceptible) amount.
Skip Montanaro979c74b2002-09-03 21:25:14 +0000119
Tim Petersd64c1de2002-08-12 17:36:03 +0000120- When multiplying very large integers, a version of the so-called
121 Karatsuba algorithm is now used. This is most effective if the
122 inputs have roughly the same size. If they both have about N digits,
123 Karatsuba multiplication has O(N**1.58) runtime (the exponent is
124 log_base_2(3)) instead of the previous O(N**2). Measured results may
Tim Peters012c0a32002-08-16 03:40:07 +0000125 be better or worse than that, depending on platform quirks. Besides
126 the O() improvement in raw instruction count, the Karatsuba algorithm
127 appears to have much better cache behavior on extremely large integers
128 (starting in the ballpark of a million bits). Note that this is a
129 simple implementation, and there's no intent here to compete with,
130 e.g., GMP. It gives a very nice speedup when it applies, but a package
131 devoted to fast large-integer arithmetic should run circles around it.
Tim Peters5af4e6c2002-08-12 02:31:19 +0000132
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000133- u'%c' will now raise a ValueError in case the argument is an
134 integer outside the valid range of Unicode code point ordinals.
135
Guido van Rossumdeb09362002-08-09 17:16:30 +0000136- The tempfile module has been overhauled for enhanced security. The
137 mktemp() function is now deprecated; new, safe replacements are
138 mkstemp() (for files) and mkdtemp() (for directories), and the
139 higher-level functions NamedTemporaryFile() and TemporaryFile().
140 Use of some global variables in this module is also deprecated; the
141 new functions have keyword arguments to provide the same
142 functionality. All Lib, Tools and Demo modules that used the unsafe
143 interfaces have been updated to use the safe replacements. Thanks
144 to Zack Weinberg!
145
Guido van Rossumd81a9832002-08-09 15:57:34 +0000146- When x is an object whose class implements __mul__ and __rmul__,
147 1.0*x would correctly invoke __rmul__, but 1*x would erroneously
148 invoke __mul__. This was due to the sequence-repeat code in the int
149 type. This has been fixed now.
150
Barry Warsawd79f6832002-08-06 17:01:51 +0000151- Previously, "str1 in str2" required str1 to be a string of length 1.
152 This restriction has been relaxed to allow str1 to be a string of
153 any length. Thus "'el' in 'hello world'" returns True now.
154
Guido van Rossumb57089c2002-08-06 16:20:26 +0000155- File objects are now their own iterators. For a file f, iter(f) now
156 returns f (unless f is closed), and f.next() is similar to
157 f.readline() when EOF is not reached; however, f.next() uses a
158 readahead buffer that messes up the file position, so mixing
159 f.next() and f.readline() (or other methods) doesn't work right.
160 Calling f.seek() drops the readahead buffer, but other operations
161 don't. It so happens that this gives a nice additional speed boost
162 to "for line in file:"; the xreadlines method and corresponding
Guido van Rossumbffb2ef2002-08-09 17:17:07 +0000163 module are now obsolete. Thanks to Oren Tirosh!
Guido van Rossumb57089c2002-08-06 16:20:26 +0000164
Guido van Rossumde392d32002-08-05 14:17:20 +0000165- Encoding declarations (PEP 263, phase 1) have been implemented. A
166 comment of the form "# -*- coding: <encodingname> -*-" in the first
167 or second line of a Python source file indicates the encoding.
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +0000168
Tim Petersf47630f2002-08-01 02:34:51 +0000169- list.sort() has a new implementation. While cross-platform results
170 may vary, and in data-dependent ways, this is much faster on many
171 kinds of partially ordered lists than the previous implementation,
172 and reported to be just as fast on randomly ordered lists on
173 several major platforms. This sort is also stable (if A==B and A
174 precedes B in the list at the start, A precedes B after the sort too),
175 although the language definition does not guarantee stability. A
176 potential drawback is that list.sort() may require temp space of
Skip Montanaroa2a07bc2002-09-30 15:23:01 +0000177 len(list)*2 bytes (``*4`` on a 64-bit machine). It's therefore possible
Tim Petersf47630f2002-08-01 02:34:51 +0000178 for list.sort() to raise MemoryError now, even if a comparison function
179 does not. See <http://www.python.org/sf/587076> for full details.
180
Guido van Rossum2d5389c2002-07-23 03:44:35 +0000181- All standard iterators now ensure that, once StopIteration has been
182 raised, all future calls to next() on the same iterator will also
183 raise StopIteration. There used to be various counterexamples to
184 this behavior, which could caused confusion or subtle program
185 breakage, without any benefits. (Note that this is still an
186 iterator's responsibility; the iterator framework does not enforce
187 this.)
188
Mark Hammondc0e35152002-07-16 01:32:30 +0000189- Ctrl+C handling on Windows has been made more consistent with
190 other platforms. KeyboardInterrupt can now reliably be caught,
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +0000191 and Ctrl+C at an interactive prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +0000192 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Peters5af4e6c2002-08-12 02:31:19 +0000193 interrupt time.sleep() in the main thread, and any child processes
194 created via the popen family (on win2k; we can't make win9x work
Mark Hammond8f3afc72002-08-10 06:26:31 +0000195 reliably) are also interrupted (as generally happens on for Linux/Unix.)
196 [SF bugs 231273, 439992 and 581232]
Mark Hammondc0e35152002-07-16 01:32:30 +0000197
Mark Hammond8696ebc2002-10-08 02:44:31 +0000198- sys.getwindowsversion() has been added on Windows. This
199 returns a tuple with information about the version of Windows
200 currently running.
201
Raymond Hettinger5a04aec2002-06-25 00:25:30 +0000202- Slices and repetitions of buffer objects now consistently return
203 a string. Formerly, strings would be returned most of the time,
204 but a buffer object would be returned when the repetition count
205 was one or when the slice range was all inclusive.
206
Walter Dörwald3430d702002-06-17 10:43:59 +0000207- Unicode objects in sys.path are no longer ignored but treated
208 as directory names.
209
Neal Norwitz1f68fc72002-06-14 00:50:42 +0000210- Fixed string.startswith and string.endswith builtin methods
211 so they accept negative indices. [SF bug 493951]
212
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +0000213- Fixed a bug with a continue inside a try block and a yield in the
214 finally clause. [SF bug 567538]
215
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +0000216- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +0000217 with a third "stride" parameter. For example, "hello world"[::-1]
218 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +0000219
Neal Norwitzd68f5172002-05-29 15:54:55 +0000220- A new warning PendingDeprecationWarning was added to provide
221 direction on features which are in the process of being deprecated.
222 The warning will not be printed by default. To see the pending
223 deprecations, use -Walways::PendingDeprecationWarning::
224 as a command line option or warnings.filterwarnings() in code.
225
Fred Draked0ba6362002-05-02 21:28:26 +0000226- Deprecated features of xrange objects have been removed as
227 promised. The start, stop, and step attributes and the tolist()
228 method no longer exist. xrange repetition and slicing have been
229 removed.
230
Guido van Rossum7dab2422002-04-26 19:40:56 +0000231- New builtin function enumerate(x), from PEP 279. Example:
232 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
233 The argument can be an arbitrary iterable object.
234
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000235- The assert statement no longer tests __debug__ at runtime. This means
236 that assert statements cannot be disabled by assigning a false value
237 to __debug__.
238
Walter Dörwald068325e2002-04-15 13:36:47 +0000239- A method zfill() was added to str and unicode, that fills a numeric
240 string to the left with zeros. For example,
241 "+123".zfill(6) -> "+00123".
242
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000243- Complex numbers supported divmod() and the // and % operators, but
244 these make no sense. Since this was documented, they're being
245 deprecated now.
246
Guido van Rossum26dd8302002-04-26 20:11:29 +0000247- String and unicode methods lstrip(), rstrip() and strip() now take
248 an optional argument that specifies the characters to strip. For
249 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000250
Guido van Rossumc69343b2002-04-12 19:22:48 +0000251- Added a new dict method pop(key). This removes and returns the
252 value corresponding to key. [SF patch #539949]
253
Guido van Rossum47834462002-04-04 15:21:33 +0000254- A new built-in type, bool, has been added, as well as built-in
255 names for its two values, True and False. Comparisons and sundry
256 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000257 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000258 is backward compatible.
259
Guido van Rossum95b62a62002-03-29 01:07:24 +0000260- Fixed two bugs reported as SF #535905: under certain conditions,
261 deallocating a deeply nested structure could cause a segfault in the
262 garbage collector, due to interaction with the "trashcan" code;
263 access to the current frame during destruction of a local variable
264 could access a pointer to freed memory.
265
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000266- The optional object allocator ("pymalloc") has been enabled by
267 default. The recommended practice for memory allocation and
268 deallocation has been streamlined. A header file is included,
269 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
270 and lets them use the same API with Python versions from 1.5.2
271 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000272
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000273- PyErr_Display will provide file and line information for all exceptions
274 that have an attribute print_file_and_line, not just SyntaxErrors.
275
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000276- The UTF-8 codec will now encode and decode Unicode surrogates
277 correctly and without raising exceptions for unpaired ones.
278
Guido van Rossumadd88062002-08-15 14:01:14 +0000279- Universal newlines (PEP 278) is implemented. Briefly, using 'U'
280 instead of 'r' when opening a text file for reading changes the line
281 ending convention so that any of '\r', '\r\n', and '\n' is
282 recognized (even mixed in one file); all three are converted to
283 '\n', the standard Python line end character.
284
Neal Norwitz649b7592002-01-01 19:07:13 +0000285- file.xreadlines() now raises a ValueError if the file is closed:
286 Previously, an xreadlines object was returned which would raise
287 a ValueError when the xreadlines.next() method was called.
288
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000289- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000290 An exception will now be raised if more than one argument is used.
291
Tim Petersaf8446f2001-12-21 21:36:50 +0000292Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000293-----------------
Tim Petersaf8446f2001-12-21 21:36:50 +0000294
Neal Norwitz94a83fd2002-11-02 17:46:24 +0000295- resource.getrlimit() now returns longs instead of ints.
296
Martin v. Löwis080689c2002-10-26 14:42:02 +0000297- readline now dynamically adjusts its input/output stream if
298 sys.stdin/stdout changes.
299
Guido van Rossumba602972002-10-01 18:18:58 +0000300- The _tkinter module (and hence Tkinter) has dropped support for
301 Tcl/Tk 8.0 and 8.1. Only Tcl/Tk versions 8.2, 8.3 and 8.4 are
302 supported.
303
Martin v. Löwis658009a2002-09-16 17:26:24 +0000304- cPickle.BadPickleGet is now a class.
305
Martin v. Löwisa19bfe02002-10-16 18:28:36 +0000306- The time stamps in os.stat_result are floating point numbers
307 after stat_float_times has been called.
Martin v. Löwis94717ed2002-09-09 14:24:16 +0000308
Neal Norwitzb5673922002-09-05 21:48:07 +0000309- If the size passed to mmap.mmap() is larger than the length of the
310 file on non-Windows platforms, a ValueError is raised. [SF bug 585792]
311
Guido van Rossumb57089c2002-08-06 16:20:26 +0000312- The xreadlines module is slated for obsolescence.
313
Guido van Rossum79f0a102002-07-23 03:32:08 +0000314- The strptime function in the time module is now always available (a
315 Python implementation is used when the C library doesn't define it).
316
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000317- The 'new' module is no longer an extension, but a Python module that
318 only exists for backwards compatibility. Its contents are no longer
319 functions but callable type objects.
320
Tim Peters81b92512002-04-29 01:37:32 +0000321- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000322 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000323 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000324
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000325- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
326 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000327
Martin v. Löwisf0a46682002-11-03 17:20:12 +0000328- The locale module now exposes the C library's gettext interface. It
329 also has a new function getpreferredencoding.
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000330
Tim Petersfbf74f22002-03-14 19:06:01 +0000331- A security hole ("double free") was found in zlib-1.1.3, a popular
332 third party compression library used by some Python modules. The
333 hole was quickly plugged in zlib-1.1.4, and the Windows build of
334 Python now ships with zlib-1.1.4.
335
Martin v. Löwis688357e2002-04-08 21:28:20 +0000336- pwd, grp, and resource return enhanced tuples now, with symbolic
337 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000338
Martin v. Löwis99866332002-03-01 10:27:01 +0000339- array.array is now a type object. A new format character
340 'u' indicates Py_UNICODE arrays. For those, .tounicode and
341 .fromunicode methods are available. Arrays now support __iadd__
342 and __imul__.
343
Neal Norwitze790eae2002-01-01 21:14:12 +0000344- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000345 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
346 is called.
347
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000348- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
349 been added where available.
350
Skip Montanaro8e790e72002-09-03 13:25:17 +0000351- The sys module acquired a new attribute, api_version, which evaluates
352 to the value of the PYTHON_API_VERSION macro with which the
353 interpreter was compiled.
354
Tim Petersaf8446f2001-12-21 21:36:50 +0000355Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000356-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000357
Tim Peters9288f952002-11-05 20:38:55 +0000358- gzip.py now handles files exceeding 2GB. Files over 4GB also work
359 now (provided the OS supports it, and Python is configured with large
360 file support), but in that case the underlying gzip file format can
361 record only the least-significant 32 bits of the file size, so that
362 some tools working with gzipped files may report an incorrect file
363 size.
Tim Petersfb0ea522002-11-04 19:50:11 +0000364
Martin v. Löwis74b51ac2002-10-26 14:50:45 +0000365- xml.sax.saxutils.unescape has been added, to replace entity references
366 with their entity value.
367
Martin v. Löwis77ac4292002-10-15 15:11:13 +0000368- Queue.Queue.{put,get} now support an optional timeout argument.
369
Martin v. Löwisb24e3472002-10-13 10:28:04 +0000370- Various features of Tk 8.4 are exposed in Tkinter.py. The multiple
371 option of tkFileDialog is exposed as function askopenfile{,name}s.
Martin v. Löwis2ec36272002-10-13 10:22:08 +0000372
Martin v. Löwisb24e3472002-10-13 10:28:04 +0000373- Various configure methods of Tkinter have been stream-lined, so that
374 tag_configure, image_configure, window_configure now return a
Tim Petersfb0ea522002-11-04 19:50:11 +0000375 dictionary when invoked with no argument.
Martin v. Löwis6ce13152002-10-10 14:36:13 +0000376
Guido van Rossum2b492b62002-10-09 21:40:48 +0000377- Importing the readline module now no longer has the side effect of
378 calling setlocale(LC_CTYPE, ""). The initial "C" locale, or
379 whatever locale is explicitly set by the user, is preserved. If you
380 want repr() of 8-bit strings in your preferred encoding to preserve
381 all printable characters of that encoding, you have to add the
382 following code to your $PYTHONSTARTUP file or to your application's
383 main():
384
385 import locale
386 locale.setlocale(locale.LC_CTYPE, "")
387
Martin v. Löwise9ce0b02002-10-07 13:23:24 +0000388- shutil.move was added. shutil.copytree now reports errors as an
389 exception at the end, instead of printing error messages.
390
Marc-André Lemburg97047e22002-10-04 11:55:21 +0000391- Encoding name normalization was generalized to not only
392 replace hyphens with underscores, but also all other non-alphanumeric
393 characters (with the exception of the dot which is used for Python
394 package names during lookup). The aliases.py mapping was updated
395 to the new standard.
396
Walter Dörwald5ccaf8f2002-09-06 16:15:58 +0000397- mimetypes has two new functions: guess_all_extensions() which
398 returns a list of all known extensions for a mime type, and
399 add_type() which adds one mapping between a mime type and
400 an extension to the database.
401
Guido van Rossumd8ab35c2002-08-19 16:25:46 +0000402- New module: sets, defines the class Set that implements a mutable
403 set type using the keys of a dict to represent the set. There's
404 also a class ImmutableSet which is useful when you need sets of sets
405 or when you need to use sets as dict keys, and a class BaseSet which
406 is the base class of the two. (This is not documented yet, but
407 help(sets) gives a wealth of information.)
408
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +0000409- Added operator.pow(a,b) which is equivalent to a**b.
410
Tim Peters012c0a32002-08-16 03:40:07 +0000411- random.randrange(-sys.maxint-1, sys.maxint) no longer raises
412 OverflowError. That is, it now accepts any combination of 'start'
413 and 'stop' arguments so long as each is in the range of Python's
414 bounded integers.
415
Guido van Rossum4a57c332002-08-02 18:05:20 +0000416- New "algorithms" module: heapq, implements a heap queue. Thanks to
417 Kevin O'Connor for the code and François Pinard for an entertaining
418 write-up explaining the theory and practical uses of heaps.
419
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000420- New encoding for the Palm OS character set: palmos.
421
Tim Peters943382c2002-07-07 03:59:34 +0000422- binascii.crc32() and the zipfile module had problems on some 64-bit
423 platforms. These have been fixed. On a platform with 8-byte C longs,
424 crc32() now returns a signed-extended 4-byte result, so that its value
425 as a Python int is equal to the value computed a 32-bit platform.
426
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000427- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
428 argument.
429
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000430- Some fixes in the copy module: when an object is copied through its
431 __reduce__ method, there was no check for a __setstate__ method on
432 the result [SF patch 565085]; deepcopy should treat instances of
433 custom metaclasses the same way it treats instances of type 'type'
434 [SF patch 560794].
435
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000436- Sockets now support timeout mode. After s.settimeout(T), where T is
437 a float expressing seconds, subsequent operations raise an exception
438 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000439 mode, use s.settimeout(None). There's also a module function,
440 socket.setdefaulttimeout(T), which sets the default for all sockets
441 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000442
443- getopt.gnu_getopt was added. This supports GNU-style option
444 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000445
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000446- Stop using strings for exceptions. String objects used for
447 exceptions are now classes deriving from Exception. The objects
448 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
449 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000450
Walter Dörwald474458d2002-06-04 15:16:29 +0000451- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
452 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
453 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
454 big endian systems were added to the codecs module. The old names
455 BOM32_* and BOM64_* were off by a factor of 2.
456
Guido van Rossumf9257822002-06-18 20:43:18 +0000457- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000458
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000459- ftplib.retrlines() now tests for callback is None rather than testing
460 for False. Was causing an error when given a callback object which
461 was callable but also returned len() as zero. The change may
462 create new breakage if the caller relied on the undocumented behavior
463 and called with callback set to [] or some other False value not
464 identical to None.
465
Tim Peters46c04e12002-05-05 20:40:00 +0000466- random.gauss() uses a piece of hidden state used by nothing else,
467 and the .seed() and .whseed() methods failed to reset it. In other
468 words, setting the seed didn't completely determine the sequence of
469 results produced by random.gauss(). It does now. Programs repeatedly
470 mixing calls to a seed method with calls to gauss() may see different
471 results now.
472
Fred Drake7f781c92002-05-01 20:33:53 +0000473- The pickle.Pickler class grew a clear_memo() method to mimic that
474 provided by cPickle.Pickler.
475
Tim Peters81b92512002-04-29 01:37:32 +0000476- difflib's SequenceMatcher class now does a dynamic analysis of
477 which elements are so frequent as to constitute noise. For
478 comparing files as sequences of lines, this generally works better
479 than the IS_LINE_JUNK function, and function ndiff's linejunk
480 argument defaults to None now as a result. A happy benefit is
481 that SequenceMatcher may run much faster now when applied
482 to large files with many duplicate lines (for example, C program
483 text with lots of repeated "}" and "return NULL;" lines).
484
Guido van Rossum256705b2002-04-23 13:29:43 +0000485- New Text.dump() method in Tkinter module.
486
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000487- New distutils commands for building packagers were added to
488 support pkgtool on Solaris and swinstall on HP-UX.
489
490- distutils now has a new abstract binary packager base class
491 command/bdist_packager, which simplifies writing packagers.
492 This will hopefully provide the missing bits to encourage
493 people to submit more packagers, e.g. for Debian, FreeBSD
494 and other systems.
495
Guido van Rossumf9257822002-06-18 20:43:18 +0000496- The UTF-16, -LE and -BE stream readers now raise a
497 NotImplementedError for all calls to .readline(). Previously, they
498 used to just produce garbage or fail with an encoding error --
499 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 +0000500 work well with these.
501
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000502- compileall now supports quiet operation.
503
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000504- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000505 connections.
506
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000507- socket module: the SSL support was broken out of the main
508 _socket module C helper and placed into a new _ssl helper
509 which now gets imported by socket.py if available and working.
510
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000511- encodings package: added aliases for all supported IANA character
512 sets
513
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000514- ftplib: to safeguard the user's privacy, anonymous login will use
515 "anonymous@" as default password, rather than the real user and host
516 name.
517
Fred Drake36736122002-01-10 13:50:31 +0000518- webbrowser: tightened up the command passed to os.system() so that
519 arbitrary shell code can't be executed because a bogus URL was
520 passed in.
521
Tim Peters11bd9942002-02-01 00:52:29 +0000522- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000523 gettext.find an optional all argument. Translations will now fallback
524 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000525
Martin v. Löwis9668b932002-01-12 11:27:42 +0000526- distutils bdist commands now offer a --skip-build option.
527
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000528- warnings.warn now accepts a Warning instance as first argument.
529
Fred Drakefed7e852002-04-04 19:36:15 +0000530- The xml.sax.expatreader.ExpatParser class will no longer create
531 circular references by using itself as the locator that gets passed
532 to the content handler implementation. [SF bug #535474]
533
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000534- The email.Parser.Parser class now properly parses strings regardless
535 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
536 or CRLF). Also, the Header class's constructor default arguments
537 has changed slightly so that an explicit maxlinelen value is always
538 honored.
539
Gustavo Niemeyerf8ca8362002-11-05 16:50:05 +0000540- distutils' build_ext command now links c++ extensions with the c++
541 compiler available in the Makefile or CXX environment variable, if
542 running under *nix.
543
544- New module bz2: provides a comprehensive interface for the bz2 compression
545 library. It implements a complete file interface, one-shot (de)compression
546 functions, and types for sequential (de)compression.
547
Barry Warsaw5d8d6182002-11-05 22:41:33 +0000548- New pdb command `pp' which is like `p' except that it pretty-prints
549 the value of its expression argument.
550
Tim Petersaf8446f2001-12-21 21:36:50 +0000551Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000552-----------
Tim Petersaf8446f2001-12-21 21:36:50 +0000553
Guido van Rossum923e4ef2002-09-17 20:58:59 +0000554- The SGI demos (Demo/sgi) have been removed. Nobody thought they
555 were interesting any more. (The SGI library modules and extensions
556 are still there; it is believed that at least some of these are
557 still used and useful.)
558
Fred Drake40813b12002-08-05 15:24:19 +0000559- IDLE supports the new encoding declarations (PEP 263); it can also
560 deal with legacy 8-bit files if they use the locale's encoding. It
561 allows non-ASCII strings in the interactive shell and executes them
562 in the locale's encoding.
Martin v. Löwis98ce7b72002-08-05 15:11:26 +0000563
Marc-André Lemburg46260092002-04-04 16:17:11 +0000564- freeze.py now produces binaries which can import shared modules,
565 unlike before when this failed due to missing symbol exports in
566 the generated binary.
567
Tim Petersaf8446f2001-12-21 21:36:50 +0000568Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000569-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000570
Guido van Rossum6b3db552002-09-25 15:02:44 +0000571- The fpectl module is not built by default; it's dangerous or useless
572 except in the hands of experts.
573
Tim Petersf47630f2002-08-01 02:34:51 +0000574- The public Python C API will generally be declared using PyAPI_FUNC
Guido van Rossum6b3db552002-09-25 15:02:44 +0000575 and PyAPI_DATA macros, while Python extension module init functions
576 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
577 are deprecated.
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000578
Tim Petersc6a3ff62002-07-08 22:11:52 +0000579- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
580 get into infinite loops, when a new-style class got garbage-collected.
581 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
582 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
583 COUNT_ALLOCS is not enabled by default, in either release or debug
584 builds, and that new-style classes are immortal only in COUNT_ALLOCS
585 builds.
586
Tim Peters943382c2002-07-07 03:59:34 +0000587- Compiling out the cyclic garbage collector is no longer an option.
588 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
589 that it's always defined (for the benefit of any extension modules
590 that may be conditionalizing on it). A bonus is that any extension
591 type participating in cyclic gc can choose to participate in the
592 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
593 to require editing the core to teach the trashcan mechanism about the
594 new type.
595
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000596- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000597
598 The Standard C macro HUGE_VAL and its float and long double analogs,
599 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
600 positive infinities.
601
602 Python only uses the double HUGE_VAL, and only to #define its own symbol
603 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
604 pyport.h used to try to worm around that, but the workarounds triggered
605 other bugs on other platforms, so we gave up. If your platform defines
606 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
607 that works on your platform. The only instance of this I'm sure about
608 is on an unknown subset of Cray systems, described here:
609
610 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
611
612 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
613
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000614- The configure option --without-doc-strings can be used to remove the
615 doc strings from the builtin functions and modules; this reduces the
616 size of the executable.
617
Guido van Rossumadd88062002-08-15 14:01:14 +0000618- The universal newlines option (PEP 278) is on by default. On Unix
619 it can be disabled by passing --without-universal-newlines to the
620 configure script. On other platforms, remove
621 WITH_UNIVERSAL_NEWLINES from pyconfig.h.
Tim Peters639295f2002-04-21 07:30:30 +0000622
Martin v. Löwis1142de32002-03-29 16:28:31 +0000623- On Unix, a shared libpython2.3.so can be created with --enable-shared.
624
Tim Peters8deda702002-03-30 10:06:07 +0000625- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
626 preprocessor symbols were eliminated. The internal decisions they
627 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000628
Fred Drake7d28b732002-05-02 21:17:00 +0000629- The tools used to build the documentation now work under Cygwin as
630 well as Unix.
631
Skip Montanaro57454e52002-06-14 20:30:31 +0000632- The bsddb and dbm module builds have been changed to try and avoid version
633 skew problems and disable linkage with Berkeley DB 1.85 unless the
634 installer knows what s/he's doing. See the section on building these
635 modules in the README file for details.
636
Tim Petersaf8446f2001-12-21 21:36:50 +0000637C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000638-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000639
Guido van Rossum45ec02a2002-08-19 21:43:18 +0000640- The string object's layout has changed: the pointer member
641 ob_sinterned has been replaced by an int member ob_sstate. On some
642 platforms (e.g. most 64-bit systems) this may change the offset of
643 the ob_sval member, so as a precaution the API_VERSION has been
644 incremented. The apparently unused feature of "indirect interned
645 strings", supported by the ob_sinterned member, is gone. Interned
646 strings are now usually mortal; theres a new API,
647 PyString_InternImmortal() that creates immortal interned strings.
648 (The ob_sstate member can only take three values; however, while
649 making it a char saves a few bytes per string object on average, in
650 it also slowed things down a bit because ob_sval was no longer
651 aligned.)
652
Guido van Rossumfdb86482002-08-14 21:20:32 +0000653- The Py_InitModule*() functions now accept NULL for the 'methods'
654 argument. Modules without global functions are becoming more common
655 now that factories can be types rather than functions.
656
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000657- New C API PyUnicode_FromOrdinal() which exposes unichr() at C
658 level.
659
Thomas Heller085358a2002-07-29 14:27:41 +0000660- New functions PyErr_SetExcFromWindowsErr() and
661 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
662 PyErr_SetFromWindowsErrWithFilename() and
663 PyErr_SetFromWindowsErr(), but they allow to specify
664 the exception type to raise. Available on Windows.
665
Tim Peters7c321a82002-07-09 02:57:01 +0000666- Py_FatalError() is now declared as taking a const char* argument. It
667 was previously declared without const. This should not affect working
668 code.
669
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000670- Added new macro PySequence_ITEM(o, i) that directly calls
671 sq_item without rechecking that o is a sequence and without
672 adjusting for negative indices.
673
Fred Draked0ba6362002-05-02 21:28:26 +0000674- PyRange_New() now raises ValueError if the fourth argument is not 1.
675 This is part of the removal of deprecated features of the xrange
676 object.
677
Guido van Rossum517c7d42002-04-26 02:49:14 +0000678- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
679 coercion if both arguments have the same type but this type has the
680 CHECKTYPES flag set. This is to better support proxies.
681
Skip Montanaroa2a07bc2002-09-30 15:23:01 +0000682- The type of tp_free has been changed from "``void (*)(PyObject *)``" to
683 "``void (*)(void *)``".
Neil Schemenauer9344b142002-04-12 23:00:08 +0000684
685- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
686
Guido van Rossum0986d822002-04-08 01:38:42 +0000687- A type can now inherit its metatype from its base type. Previously,
688 when PyType_Ready() was called, if ob_type was found to be NULL, it
689 was always set to &PyType_Type; now it is set to base->ob_type,
690 where base is tp_base, defaulting to &PyObject_Type.
691
692- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
693
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000694- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000695
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000696- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000697 without going through the buffer API.
698
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000699- The enumerators of cmp_op have been renamed to use the prefix ``PyCmp_``.
Martin v. Löwis7198a522002-01-01 19:59:11 +0000700
Tim Peters10a3bb52001-12-25 19:07:38 +0000701- An old #define of ANY as void has been removed from pyport.h. This
702 hasn't been used since Python's pre-ANSI days, and the #define has
703 been marked as obsolete since then. SF bug 495548 says it created
704 conflicts with other packages, so keeping it around wasn't harmless.
705
Tim Petersaf8446f2001-12-21 21:36:50 +0000706- Because Python's magic number scheme broke on January 1st, we decided
707 to stop Python development. Thanks for all the fish!
708
Tim Petersfb05db22002-03-11 00:24:00 +0000709- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000710 scheme to a new one. See Python/import.c for details.
711
Tim Petersaf8446f2001-12-21 21:36:50 +0000712New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000713-------------
Tim Petersaf8446f2001-12-21 21:36:50 +0000714
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000715- AtheOS is now supported.
716
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000717- the EMX runtime environment on OS/2 is now supported.
718
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000719- GNU/Hurd is now supported.
720
Tim Petersaf8446f2001-12-21 21:36:50 +0000721Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000722-----
723
724Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000725
726Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000727-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000728
Tim Peters08e72952002-04-16 20:48:01 +0000729- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
730 of that has been fixed in the installer (disabled Wise's "delete in-
731 use files" uninstall option).
732
Guido van Rossum181e41a2002-04-06 00:23:25 +0000733- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
734
Tim Peters33187922002-04-04 20:02:04 +0000735- The installer now installs Start menu shortcuts under (the local
736 equivalent of) "All Users" when doing an Admin install.
737
Tim Petersfb05db22002-03-11 00:24:00 +0000738- file.truncate([newsize]) now works on Windows for all newsize values.
739 It used to fail if newsize didn't fit in 32 bits, reflecting a
740 limitation of MS _chsize (which is no longer used).
741
Tim Petersab034fa2002-02-01 11:27:43 +0000742- os.waitpid() is now implemented for Windows, and can be used to block
743 until a specified process exits. This is similar to, but not exactly
744 the same as, os.waitpid() on POSIX systems. If you're waiting for
745 a specific process whose pid was obtained from one of the spawn()
746 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000747 See the docs for details. The docs were changed to clarify that
748 spawn functions return, and waitpid requires, a process handle on
749 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000750
Tim Peters11bd9942002-02-01 00:52:29 +0000751- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000752 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000753 to a nasty problem: before 2.3, if you got a temp file on Windows, it
754 got wrapped in an object whose close() method first closed the
755 underlying file, then deleted the file. This usually worked fine.
756 However, the spawn family of functions on Windows create (at a low C
757 level) the same set of open files in the spawned process Q as were
758 open in the spawning process P. If a temp file f was among them, then
759 doing f.close() in P first closed P's C-level file handle on f, but Q's
760 C-level file handle on f remained open, so the attempt in P to delete f
761 blew up with a "Permission denied" error (Windows doesn't allow
762 deleting open files). This was surprising, subtle, and difficult to
763 work around.
764
765- The os module now exports all the symbolic constants usable with the
766 low-level os.open() on Windows: the new constants in 2.3 are
767 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
768 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
769 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
770 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
771 (so specify both if you want both; note that neither is useful unless
772 specified with O_CREAT too).
773
Tim Petersaf8446f2001-12-21 21:36:50 +0000774Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000775----
776
777Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000778
779
Tim Peters909c0912001-12-14 23:16:18 +0000780What's New in Python 2.2 final?
Tim Peters909c0912001-12-14 23:16:18 +0000781===============================
782
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000783*Release date: 21-Dec-2001*
784
Tim Peters909c0912001-12-14 23:16:18 +0000785Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000786--------------------------------------------
Tim Peters909c0912001-12-14 23:16:18 +0000787
Barry Warsaw52acb492001-12-21 20:04:22 +0000788- pickle.py, cPickle: allow pickling instances of new-style classes
789 with a custom metaclass.
790
Tim Peters909c0912001-12-14 23:16:18 +0000791Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000792-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000793
Barry Warsaw52acb492001-12-21 20:04:22 +0000794- weakref proxy object: when comparing, unwrap both arguments if both
795 are proxies.
796
Tim Peters909c0912001-12-14 23:16:18 +0000797Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000798-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000799
Barry Warsaw52acb492001-12-21 20:04:22 +0000800- binascii.b2a_base64(): fix a potential buffer overrun when encoding
801 very short strings.
802
803- cPickle: the obscure "fast" mode was suspected of causing stack
804 overflows on the Mac. Hopefully fixed this by setting the recursion
805 limit much smaller. If the limit is too low (it only affects
806 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
807 when compiling cPickle.c (or in pyconfig.h).
808
Tim Peters909c0912001-12-14 23:16:18 +0000809Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000810-------
Tim Peters909c0912001-12-14 23:16:18 +0000811
Barry Warsaw52acb492001-12-21 20:04:22 +0000812- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
813 close or delete time).
814
815- rfc822.py: fixed a bug where the address '<>' was converted to None
816 instead of an empty string (also fixes the email.Utils module).
817
818- xmlrpclib.py: version 1.0.0; uses precision for doubles.
819
820- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000821 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000822
Tim Peters909c0912001-12-14 23:16:18 +0000823Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000824-----------
Tim Peters909c0912001-12-14 23:16:18 +0000825
826Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000827-----
Tim Peters909c0912001-12-14 23:16:18 +0000828
829C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000830-----
Tim Peters909c0912001-12-14 23:16:18 +0000831
832New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000833-------------
Tim Peters909c0912001-12-14 23:16:18 +0000834
835Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000836-----
Tim Peters909c0912001-12-14 23:16:18 +0000837
838Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000839-------
Tim Peters909c0912001-12-14 23:16:18 +0000840
Barry Warsaw52acb492001-12-21 20:04:22 +0000841- distutils package: fixed broken Windows installers (bdist_wininst).
842
843- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
844 instances are deleted at process exit time.
845
846- socket.py: prevent mysterious warnings when socket instances are
847 deleted at process exit time.
848
849- posixmodule.c: fix a Windows crash with stat() of a filename ending
850 in backslash.
851
Tim Peters909c0912001-12-14 23:16:18 +0000852Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000853----
Tim Peters909c0912001-12-14 23:16:18 +0000854
Barry Warsaw52acb492001-12-21 20:04:22 +0000855- The Carbon toolbox modules have been upgraded to Universal Headers
856 3.4, and experimental CoreGraphics and CarbonEvents modules have
857 been added. All only for framework-enabled MacOSX.
858
Tim Peters909c0912001-12-14 23:16:18 +0000859
Tim Peters6272dfd2001-12-13 19:34:00 +0000860What's New in Python 2.2c1?
Tim Petersb3c9af12001-11-17 00:21:57 +0000861===========================
862
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000863*Release date: 14-Dec-2001*
864
Tim Petersb3c9af12001-11-17 00:21:57 +0000865Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000866--------------------------------------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000867
Barry Warsaw06557452001-12-14 20:47:12 +0000868- Guido's tutorial introduction to the new type/class features has
869 been extensively updated. See
870
871 http://www.python.org/2.2/descrintro.html
872
873 That remains the primary documentation in this area.
874
Guido van Rossum33bab012001-12-05 22:45:48 +0000875- Fixed a leak: instance variables declared with __slots__ were never
876 deleted!
877
Guido van Rossum4b800852001-12-03 00:54:52 +0000878- The "delete attribute" method of descriptor objects is called
879 __delete__, not __del__. In previous releases, it was mistakenly
880 called __del__, which created an unfortunate overloading condition
881 with finalizers. (The "get attribute" and "set attribute" methods
882 are still called __get__ and __set__, respectively.)
883
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000884- Some subtle issues with the super built-in were fixed:
885
886 (a) When super itself is subclassed, its __get__ method would still
887 return an instance of the base class (i.e., of super).
888
889 (b) super(C, C()).__class__ would return C rather than super. This
890 is confusing. To fix this, I decided to change the semantics of
891 super so that it only applies to code attributes, not to data
892 attributes. After all, overriding data attributes is not
893 supported anyway.
894
895 (c) The __get__ method didn't check whether the argument was an
896 instance of the type used in creation of the super instance.
897
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000898- Previously, hash() of an instance of a subclass of a mutable type
899 (list or dictionary) would return some value, rather than raising
900 TypeError. This has been fixed. Also, directly calling
901 dict.__hash__ and list.__hash__ now raises the same TypeError
902 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000903
Guido van Rossumd331cb52001-12-05 19:46:42 +0000904- New-style objects now support deleting their __dict__. This is for
905 all intents and purposes equivalent to assigning a brand new empty
906 dictionary, but saves space if the object is not used further.
907
Tim Petersb3c9af12001-11-17 00:21:57 +0000908Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000909-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000910
Tim Peters3caca232001-12-06 06:23:26 +0000911- -Qnew now works as documented in PEP 238: when -Qnew is passed on
912 the command line, all occurrences of "/" use true division instead
913 of classic division. See the PEP for details. Note that "all"
914 means all instances in library and 3rd-party modules, as well as in
915 your own code. As the PEP says, -Qnew is intended for use only in
916 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000917 Note that test_coercion.py in the standard Python test suite fails
918 under -Qnew; this is expected, and won't be repaired until true
919 division becomes the default (in the meantime, test_coercion is
920 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000921
Fred Drake6c01e252001-12-14 17:08:12 +0000922- complex() now only allows the first argument to be a string
923 argument, and raises TypeError if either the second arg is a string
924 or if the second arg is specified when the first is a string.
925
Tim Petersb3c9af12001-11-17 00:21:57 +0000926Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000927-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000928
Martin v. Löwis560da622001-11-24 09:24:51 +0000929- gc.get_referents was renamed to gc.get_referrers.
930
Tim Petersb3c9af12001-11-17 00:21:57 +0000931Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000932-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000933
Tim Peters25059d32001-12-07 20:35:43 +0000934- Functions in the os.spawn() family now release the global interpreter
935 lock around calling the platform spawn. They should always have done
936 this, but did not before 2.2c1. Multithreaded programs calling
937 an os.spawn function with P_WAIT will no longer block all Python threads
938 until the spawned program completes. It's possible that some programs
939 relies on blocking, although more likely by accident than by design.
940
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000941- webbrowser defaults to netscape.exe on OS/2 now.
942
Martin v. Löwis652e1912001-11-25 14:50:56 +0000943- Tix.ResizeHandle exposes detach_widget, hide, and show.
944
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000945- The charset alias windows_1252 has been added.
946
Barry Warsaw06557452001-12-14 20:47:12 +0000947- types.StringTypes is a tuple containing the defined string types;
948 usually this will be (str, unicode), but if Python was compiled
949 without Unicode support it will be just (str,).
950
951- The pulldom and minidom modules were synchronized to PyXML.
952
Tim Petersb3c9af12001-11-17 00:21:57 +0000953Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000954-----------
Tim Petersb3c9af12001-11-17 00:21:57 +0000955
Barry Warsaw06557452001-12-14 20:47:12 +0000956- A new script called Tools/scripts/google.py was added, which fires
957 off a search on Google.
958
Tim Petersb3c9af12001-11-17 00:21:57 +0000959Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000960-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000961
Barry Warsaw06557452001-12-14 20:47:12 +0000962- Note that release builds of Python should arrange to define the
963 preprocessor symbol NDEBUG on the command line (or equivalent).
964 In the 2.2 pre-release series we tried to define this by magic in
965 Python.h instead, but it proved to cause problems for extension
966 authors. The Unix, Windows and Mac builds now all define NDEBUG in
967 release builds via cmdline (or equivalent) instead. Ports to
968 other platforms should do likewise.
969
Jack Jansen1999ef42001-12-06 21:47:20 +0000970- It is no longer necessary to use --with-suffix when building on a
971 case-insensitive file system (such as Mac OS X HFS+). In the build
972 directory an extension is used, but not in the installed python.
973
Tim Petersb3c9af12001-11-17 00:21:57 +0000974C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000975-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000976
Tim Petersf582b822001-12-11 18:51:08 +0000977- New function PyDict_MergeFromSeq2() exposes the builtin dict
978 constructor's logic for updating a dictionary from an iterable object
979 producing key-value pairs.
980
Tim Peterscffed4b2001-11-29 03:26:37 +0000981- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000982 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000983 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
984 dump core in some bad cases. This has been repaired. As a result,
985 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
986 previously went unchallenged.
987
Tim Petersb3c9af12001-11-17 00:21:57 +0000988New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000989-------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000990
991Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000992-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000993
994Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000995-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000996
997Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000998----
Tim Petersb3c9af12001-11-17 00:21:57 +0000999
Jack Jansenffa260f2001-12-06 21:14:00 +00001000- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
1001 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +00001002
Barry Warsaw06557452001-12-14 20:47:12 +00001003- Changed logic for finding python home in Mac OS X framework Pythons.
1004 Now sys.executable points to the executable again, in stead of to
1005 the shared library. The latter is used only for locating the python
1006 home.
1007
1008
Tim Peters84362bc2001-10-19 17:55:30 +00001009What's New in Python 2.2b2?
Tim Peters84362bc2001-10-19 17:55:30 +00001010===========================
1011
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001012*Release date: 16-Nov-2001*
1013
Tim Peters84362bc2001-10-19 17:55:30 +00001014Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001015--------------------------------------------
Tim Peters84362bc2001-10-19 17:55:30 +00001016
Guido van Rossum3d27df02001-11-15 20:27:54 +00001017- Multiple inheritance mixing new-style and classic classes in the
1018 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +00001019
1020 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +00001021 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +00001022
1023 The MRO (method resolution order) for each base class is respected
1024 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001025 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +00001026 This needs to be documented.
1027
Tim Petersa427a2b2001-10-29 22:25:45 +00001028- The new builtin dictionary() constructor, and dictionary type, have
1029 been renamed to dict. This reflects a decade of common usage.
1030
Guido van Rossum3fc08d22001-11-15 20:33:10 +00001031- dict() now accepts an iterable object producing 2-sequences. For
1032 example, dict(d.items()) == d for any dictionary d. The argument,
1033 and the elements of the argument, can be any iterable objects.
1034
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +00001035- New-style classes can now have a __del__ method, which is called
1036 when the instance is deleted (just like for classic classes).
1037
Guido van Rossum12d955c2001-10-26 14:56:06 +00001038- Assignment to object.__dict__ is now possible, for objects that are
1039 instances of new-style classes that have a __dict__ (unless the base
1040 class forbids it).
1041
Guido van Rossumc8e56452001-10-22 00:43:43 +00001042- Methods of built-in types now properly check for keyword arguments
1043 (formerly these were silently ignored). The only built-in methods
1044 that take keyword arguments are __call__, __init__ and __new__.
1045
Guido van Rossum86443212001-10-27 22:28:54 +00001046- The socket function has been converted to a type; see below.
1047
Tim Peters84362bc2001-10-19 17:55:30 +00001048Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001049-----------------
Tim Peters84362bc2001-10-19 17:55:30 +00001050
Jeremy Hylton249aaed2001-11-09 21:06:24 +00001051- Assignment to __debug__ raises SyntaxError at compile-time. This
1052 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +00001053 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +00001054
Guido van Rossum12d955c2001-10-26 14:56:06 +00001055- Clarified the error messages for unsupported operands to an operator
1056 (like 1 + '').
1057
Tim Peters84362bc2001-10-19 17:55:30 +00001058Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001059-----------------
Tim Peters84362bc2001-10-19 17:55:30 +00001060
Tim Peters5ebfd362001-11-13 23:11:19 +00001061- mmap has a new keyword argument, "access", allowing a uniform way for
1062 both Windows and Unix users to create read-only, write-through and
1063 copy-on-write memory mappings. This was previously possible only on
1064 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001065 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +00001066 platforms. Thanks to Jay T Miller for repairing this!
1067
Tim Peters169ded02001-11-03 19:57:21 +00001068- By default, the gc.garbage list now contains only those instances in
1069 unreachable cycles that have __del__ methods; in 2.1 it contained all
1070 instances in unreachable cycles. "Instances" here has been generalized
1071 to include instances of both new-style and old-style classes.
1072
Guido van Rossum12d955c2001-10-26 14:56:06 +00001073- The socket module defines a new method for socket objects,
1074 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +00001075 send() until all data has been sent. Also, the socket function has
1076 been converted to a subclassable type, like list and tuple (etc.)
1077 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +00001078
1079- Various bugfixes to the curses module. There is now a test suite
1080 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001081
Guido van Rossum692adf12001-10-30 03:03:03 +00001082- binascii.b2a_base64 no longer places an arbitrary restriction of 57
1083 bytes on its input.
1084
Tim Peters84362bc2001-10-19 17:55:30 +00001085Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001086-------
Tim Peters84362bc2001-10-19 17:55:30 +00001087
Tim Peters5ebfd362001-11-13 23:11:19 +00001088- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +00001089 convenience function.
1090
Tim Peters75335872001-11-03 19:35:43 +00001091- Symbolic group names in regular expressions must be unique. For
1092 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
1093 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +00001094 Python 2.2 detects this error at regexp compilation time;
1095 previously, the error went undetected, and results were
1096 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
1097 pattern.subn() methods have been rewritten in C. Also, an
1098 experimental function/method finditer() has been added, which works
1099 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +00001100
Martin v. Löwisb7b32602001-11-02 23:48:20 +00001101- Tix exposes more commands through the classes DirSelectBox,
1102 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
1103 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
1104 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
1105
Tim Peters98791af2001-10-23 01:59:54 +00001106- Traceback objects are now scanned by cyclic garbage collection, so
1107 cycles created by casual use of sys.exc_info() no longer cause
1108 permanent memory leaks (provided garbage collection is enabled).
1109
Guido van Rossum49192142001-10-24 20:51:44 +00001110- os.extsep -- a new variable needed by the RISCOS support. It is the
1111 separator used by extensions, and is '.' on all platforms except
1112 RISCOS, where it is '/'. There is no need to use this variable
1113 unless you have a masochistic desire to port your code to RISCOS.
1114
Barry Warsaw012852b2001-11-16 16:17:27 +00001115- mimetypes.py has optional support for non-standard, but commonly
1116 found types. guess_type() and guess_extension() now accept an
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001117 optional 'strict' flag, defaulting to true, which controls whether
Barry Warsaw012852b2001-11-16 16:17:27 +00001118 recognize non-standard types or not. A few non-standard types we
1119 know about have been added. Also, when run as a script, there are
1120 new -l and -e options.
1121
1122- statcache is now deprecated.
1123
1124- email.Utils.formatdate() now produces the preferred RFC 2822 style
1125 dates with numeric timezones (it used to produce obsolete dates
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001126 hard coded to "GMT" timezone). An optional 'localtime' flag is
Barry Warsaw012852b2001-11-16 16:17:27 +00001127 added to produce dates in the local timezone, with daylight savings
1128 time properly taken into account.
1129
1130- In pickle and cPickle, instead of masking errors in load() by
1131 transforming them into SystemError, we let the original exception
1132 propagate out. Also, implement support for __safe_for_unpickling__
1133 in pickle, as it already was supported in cPickle.
1134
Tim Peters84362bc2001-10-19 17:55:30 +00001135Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001136-----------
Tim Peters84362bc2001-10-19 17:55:30 +00001137
1138Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001139-----
Tim Peters84362bc2001-10-19 17:55:30 +00001140
Barry Warsaw012852b2001-11-16 16:17:27 +00001141- The dbm module is built using libdb1 if available. The bsddb module
1142 is built with libdb3 if available.
1143
1144- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
1145
Tim Peters84362bc2001-10-19 17:55:30 +00001146C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001147-----
Tim Peters84362bc2001-10-19 17:55:30 +00001148
Tim Peters1fc240e2001-10-26 05:06:50 +00001149- New function PySequence_Fast_GET_SIZE() returns the size of a non-
1150 NULL result from PySequence_Fast(), more quickly than calling
1151 PySequence_Size().
1152
Barry Warsaw012852b2001-11-16 16:17:27 +00001153- New argument unpacking function PyArg_UnpackTuple() added.
1154
1155- New functions PyObject_CallFunctionObjArgs() and
1156 PyObject_CallMethodObjArgs() have been added to make it more
1157 convenient and efficient to call functions and methods from C.
1158
1159- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
1160 possible that this will propagate errors it didn't before.
1161
1162- New function PyObject_CheckReadBuffer(), which returns true if its
1163 argument supports the single-segment readable buffer interface.
1164
Tim Peters84362bc2001-10-19 17:55:30 +00001165New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001166-------------
Tim Peters84362bc2001-10-19 17:55:30 +00001167
Guido van Rossum86443212001-10-27 22:28:54 +00001168- We've finally confirmed that this release builds on HP-UX 11.00,
1169 *with* threads, and passes the test suite.
1170
Tim Peters7a33d8b2001-11-05 02:51:07 +00001171- Thanks to a series of patches from Michael Muller, Python may build
1172 again under OS/2 Visual Age C++.
1173
Guido van Rossum49192142001-10-24 20:51:44 +00001174- Updated RISCOS port by Dietmar Schwertberger.
1175
Tim Peters84362bc2001-10-19 17:55:30 +00001176Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001177-----
Tim Peters84362bc2001-10-19 17:55:30 +00001178
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001179- Added a test script for the curses module. It isn't run automatically;
1180 regrtest.py must be run with '-u curses' to enable it.
1181
Tim Peters84362bc2001-10-19 17:55:30 +00001182Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001183-------
Tim Peters84362bc2001-10-19 17:55:30 +00001184
Barry Warsaw012852b2001-11-16 16:17:27 +00001185Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001186----
Barry Warsaw012852b2001-11-16 16:17:27 +00001187
1188- PythonScript has been moved to unsupported and is slated to be
1189 removed completely in the next release.
1190
1191- It should now be possible to build applets that work on both OS9 and
1192 OSX.
1193
1194- The core is now linked with CoreServices not Carbon; as a side
1195 result, default 8bit encoding on OSX is now ASCII.
1196
1197- Python should now build on OSX 10.1.1
1198
Tim Peters84362bc2001-10-19 17:55:30 +00001199
Tim Petersabf925f2001-09-28 21:53:42 +00001200What's New in Python 2.2b1?
Tim Petersabf925f2001-09-28 21:53:42 +00001201===========================
1202
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001203*Release date: 19-Oct-2001*
1204
Tim Petersabf925f2001-09-28 21:53:42 +00001205Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001206--------------------------------------------
Tim Petersabf925f2001-09-28 21:53:42 +00001207
Guido van Rossum687ae002001-10-15 22:03:32 +00001208- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001209 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +00001210 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001211 remains: the __dict__ of a new-style class is a read-only proxy; you
1212 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +00001213 __defined__ attribute of new-style types no longer exists, for lack
1214 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001215 future a __cache__ may be resurrected with a similar function, if I
1216 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +00001217
Tim Peters1c9ca872001-10-04 06:43:12 +00001218- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
1219 always returned None, even when there was a class docstring).
1220
1221- doctest now finds and runs docstrings attached to new-style classes,
1222 class methods, static methods, and properties.
1223
Guido van Rossum9074ef62001-10-16 21:34:49 +00001224Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001225-----------------
Tim Petersabf925f2001-09-28 21:53:42 +00001226
Guido van Rossuma8bcf802001-10-15 15:53:58 +00001227- A very subtle syntactical pitfall in list comprehensions was fixed.
1228 For example: [a+b for a in 'abc', for b in 'def']. The comma in
1229 this example is a mistake. Previously, this would silently let 'a'
1230 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
1231 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
1232 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
1233 Note that [a for a in <singleton>] is a convoluted way to say
1234 [<singleton>] anyway, so it's not like any expressiveness is lost.
1235
Guido van Rossum9074ef62001-10-16 21:34:49 +00001236- getattr(obj, name, default) now only catches AttributeError, as
1237 documented, rather than returning the default value for all
1238 exceptions (which could mask bugs in a __getattr__ hook, for
1239 example).
1240
Fred Drakecb7a6b52001-10-22 18:41:51 +00001241- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +00001242 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001243 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +00001244 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +00001245
Guido van Rossum1c486092001-10-19 02:05:35 +00001246- unicode(obj) now behaves more like str(obj), accepting arbitrary
1247 objects, and calling a __unicode__ method if it exists.
1248 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +00001249 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +00001250
Barry Warsawf6fb1712001-10-19 05:35:40 +00001251- isinstance() now allows any object as the first argument and a
1252 class, a type or something with a __bases__ tuple attribute for the
1253 second argument. The second argument may also be a tuple of a
1254 class, type, or something with __bases__, in which case isinstance()
1255 will return true if the first argument is an instance of any of the
1256 things contained in the second argument tuple. E.g.
1257
1258 isinstance(x, (A, B))
1259
1260 returns true if x is an instance of A or B.
1261
Guido van Rossum9074ef62001-10-16 21:34:49 +00001262Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001263-----------------
Guido van Rossum9074ef62001-10-16 21:34:49 +00001264
1265- thread.start_new_thread() now returns the thread ID (previously None).
1266
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001267- binascii has now two quopri support functions, a2b_qp and b2a_qp.
1268
Guido van Rossumc524d952001-10-19 01:31:59 +00001269- readline now supports setting the startup_hook and the
1270 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +00001271
Guido van Rossumc524d952001-10-19 01:31:59 +00001272- os and posix supports chroot(), setgroups() and unsetenv() where
1273 available. The stat(), fstat(), statvfs() and fstatvfs() functions
1274 now return "pseudo-sequences" -- the various fields can now be
1275 accessed as attributes (e.g. os.stat("/").st_mtime) but for
1276 backwards compatibility they also behave as a fixed-length sequence.
1277 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +00001278 attributes.
1279
1280- time: localtime(), gmtime() and strptime() now return a
1281 pseudo-sequence similar to the os.stat() return value, with
1282 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +00001283
Guido van Rossum9074ef62001-10-16 21:34:49 +00001284- Decompression objects in the zlib module now accept an optional
1285 second parameter to decompress() that specifies the maximum amount
1286 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +00001287
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001288- optional SSL support in the socket module now exports OpenSSL
1289 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
1290 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +00001291 automatically seed its PRNG. Also, the keyfile and certfile
1292 arguments to socket.ssl() are now optional.
1293
1294- posixmodule (and by extension, the os module on POSIX platforms) now
1295 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001296
Guido van Rossum9074ef62001-10-16 21:34:49 +00001297Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001298-------
Guido van Rossum3c288632001-10-16 21:13:49 +00001299
Tim Peters7402f792001-10-02 03:53:41 +00001300- doctest now excludes functions and classes not defined by the module
1301 being tested, thanks to Tim Hochberg.
1302
Fred Drakecb7a6b52001-10-22 18:41:51 +00001303- HotShot, a new profiler implemented using a C-based callback, has
1304 been added. This substantially reduces the overhead of profiling,
1305 but it is still quite preliminary. Support modules and
1306 documentation will be added in upcoming releases (before 2.2 final).
1307
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001308- profile now produces correct output in situations where an exception
1309 raised in Python is cleared by C code (e.g. hasattr()). This used
1310 to cause wrong output, including spurious claims of recursive
1311 functions and attribution of time spent to the wrong function.
1312
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001313 The code and documentation for the derived OldProfile and HotProfile
1314 profiling classes was removed. The code hasn't worked for years (if
1315 you tried to use them, they raised exceptions). OldProfile
1316 intended to reproduce the behavior of the profiler Python used more
1317 than 7 years ago, and isn't interesting anymore. HotProfile intended
1318 to provide a faster profiler (but producing less information), and
1319 that's a worthy goal we intend to meet via a different approach (but
1320 without losing information).
1321
Tim Peterscce092d2001-10-09 05:31:56 +00001322- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001323 a much better system-specific calibration constant. The constant can
1324 now be specified in an instance constructor, or as a Profile class or
1325 instance variable, instead of by editing profile.py's source code.
1326 Calibration must still be done manually (see the docs for the profile
1327 module).
1328
1329 Note that Profile.calibrate() must be overriden by subclasses.
1330 Improving the accuracy required exploiting detailed knowledge of
1331 profiler internals; the earlier method abstracted away the details
1332 and measured a simplified model instead, but consequently computed
1333 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001334
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001335- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001336 which indicates whether output is intended for the header 'Q'
1337 encoding.
1338
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001339- The SocketServer.ThreadingMixIn class now closes the request after
1340 finish_request() returns. (Not when it errors out though.)
1341
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001342- The nntplib module's NNTP.body() method has grown a 'file' argument
Barry Warsawf6fb1712001-10-19 05:35:40 +00001343 to allow saving the message body to a file.
1344
1345- The email package has added a class email.Parser.HeaderParser which
1346 only parses headers and does not recurse into the message's body.
1347 Also, the module/class MIMEAudio has been added for representing
1348 audio data (contributed by Anthony Baxter).
1349
1350- ftplib should be able to handle files > 2GB.
1351
1352- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1353 ON, and OFF.
1354
Fred Drakecb7a6b52001-10-22 18:41:51 +00001355- xml.dom.minidom NodeList objects now support the length attribute
1356 and item() method as required by the DOM specifications.
1357
Guido van Rossumed554f62001-10-02 23:15:37 +00001358Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001359-----------
Guido van Rossumed554f62001-10-02 23:15:37 +00001360
1361- Demo/dns was removed. It no longer serves any purpose; a package
1362 derived from it is now maintained by Anthony Baxter, see
1363 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001364
Barry Warsawf6fb1712001-10-19 05:35:40 +00001365- The freeze tool has been made more robust, and two new options have
1366 been added: -X and -E.
1367
Tim Petersabf925f2001-09-28 21:53:42 +00001368Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001369-----
Tim Petersabf925f2001-09-28 21:53:42 +00001370
Barry Warsawf6fb1712001-10-19 05:35:40 +00001371- configure will use CXX in LINKCC if CXX is used to build main() and
1372 the system requires to link a C++ main using the C++ compiler.
1373
Tim Petersabf925f2001-09-28 21:53:42 +00001374C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001375-----
Tim Petersabf925f2001-09-28 21:53:42 +00001376
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001377- The documentation for the tp_compare slot is updated to require that
1378 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1379 not correct. This is not yet enforced but will be enforced in
1380 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1381 "NotImplemented". Right now, -1 should be used for an error return.
1382
Tim Petersd38b1c72001-09-30 05:09:37 +00001383- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1384 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1385 as long) arguments.
1386
Guido van Rossum3c288632001-10-16 21:13:49 +00001387- PyThread_start_new_thread() now returns a long int giving the thread
1388 ID, if one can be calculated; it returns -1 for error, 0 if no
1389 thread ID is calculated (this is an incompatible change, but only
1390 the thread module used this API). This code has only really been
1391 tested on Linux and Windows; other platforms please beware (and
1392 report any bugs or strange behavior).
1393
Guido van Rossum1c486092001-10-19 02:05:35 +00001394- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1395 input.
1396
Tim Petersabf925f2001-09-28 21:53:42 +00001397New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001398-------------
Tim Petersabf925f2001-09-28 21:53:42 +00001399
1400Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001401-----
Tim Petersabf925f2001-09-28 21:53:42 +00001402
1403Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001404-------
Tim Petersabf925f2001-09-28 21:53:42 +00001405
Tim Peters04cf1d32001-10-09 22:39:40 +00001406- Installer: If you install IDLE, and don't disable file-extension
1407 registration, a new "Edit with IDLE" context (right-click) menu entry
1408 is created for .py and .pyw files.
1409
Tim Peters1ce3cf72001-10-01 17:58:40 +00001410- The signal module now supports SIGBREAK on Windows, thanks to Steven
1411 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1412 action remains to call Win32 ExitProcess(). This can be changed via
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001413 signal.signal(). For example::
Tim Peters1ce3cf72001-10-01 17:58:40 +00001414
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001415 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1416 # (SIGINT) behavior.
1417 import signal
1418 signal.signal(signal.SIGBREAK, signal.default_int_handler)
Tim Peters1ce3cf72001-10-01 17:58:40 +00001419
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001420 try:
1421 while 1:
1422 pass
1423 except KeyboardInterrupt:
1424 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1425 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1426 # program without the possibility for any Python-level cleanup).
1427 print "Clean exit"
Tim Peters1ce3cf72001-10-01 17:58:40 +00001428
Tim Petersabf925f2001-09-28 21:53:42 +00001429
Tim Petersb07352e2001-09-08 01:25:47 +00001430What's New in Python 2.2a4?
1431===========================
1432
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001433*Release date: 28-Sep-2001*
1434
Guido van Rossum808eea72001-09-25 04:15:41 +00001435Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001436--------------------------------------------
Guido van Rossum808eea72001-09-25 04:15:41 +00001437
1438- pydoc and inspect are now aware of new-style classes;
1439 e.g. help(list) at the interactive prompt now shows proper
1440 documentation for all operations on list objects.
1441
1442- Applications using Jim Fulton's ExtensionClass module can now safely
1443 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1444 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1445 examples also work again. It is hoped that Gtk and Boost also work
1446 with 2.2a4 and beyond. (If you can confirm this, please write
1447 webmaster@python.org; if there are still problems, please open a bug
1448 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001449
Tim Peters66c1a522001-09-24 21:17:50 +00001450- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001451 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001452 in the constructed property object. fget, fset and fdel weren't
1453 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1454 associate a docstring with a property.
1455
Guido van Rossum808eea72001-09-25 04:15:41 +00001456- Comparison overloading is now more completely implemented. For
1457 example, a str subclass instance can properly be compared to a str
1458 instance, and it can properly overload comparison. Ditto for most
1459 other built-in object types.
1460
1461- The repr() of new-style classes has changed; instead of <type
1462 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1463 *except* for built-in types, which are still rendered as <type
1464 'Foo'> (to avoid upsetting existing code that might parse or
1465 otherwise rely on repr() of certain type objects).
1466
1467- The repr() of new-style objects is now always <Foo object at XXX>;
1468 previously, it was sometimes <Foo instance at XXX>.
1469
1470- For new-style classes, what was previously called __getattr__ is now
1471 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001472 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001473 one in classic classes is defined which is called only if regular
1474 attribute access raises AttributeError; to catch *all* attribute
1475 access, you can use __getattribute__ (for new-style classes). If
1476 both are defined, __getattribute__ is called first, and if it raises
1477 AttributeError, __getattr__ is called.
1478
1479- The __class__ attribute of new-style objects can be assigned to.
1480 The new class must have the same C-level object layout as the old
1481 class.
1482
1483- The builtin file type can be subclassed now. In the usual pattern,
1484 "file" is the name of the builtin type, and file() is a new builtin
1485 constructor, with the same signature as the builtin open() function.
1486 file() is now the preferred way to open a file.
1487
1488- Previously, __new__ would only see sequential arguments passed to
1489 the type in a constructor call; __init__ would see both sequential
1490 and keyword arguments. This made no sense whatsoever any more, so
1491 now both __new__ and __init__ see all arguments.
1492
1493- Previously, hash() applied to an instance of a subclass of str or
1494 unicode always returned 0. This has been repaired.
1495
1496- Previously, an operation on an instance of a subclass of an
1497 immutable type (int, long, float, complex, tuple, str, unicode),
1498 where the subtype didn't override the operation (and so the
1499 operation was handled by the builtin type), could return that
1500 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001501 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001502 with the same value as s.
1503
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001504- Provisional support for pickling new-style objects has been added.
1505
Guido van Rossum808eea72001-09-25 04:15:41 +00001506Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001507----
Guido van Rossum808eea72001-09-25 04:15:41 +00001508
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001509- file.writelines() now accepts any iterable object producing strings.
1510
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001511- PyUnicode_FromEncodedObject() now works very much like
1512 PyObject_Str(obj) in that it tries to use __str__/tp_str
1513 on the object if the object is not a string or buffer. This
1514 makes unicode() behave like str() when applied to non-string/buffer
1515 objects.
1516
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001517- PyFile_WriteObject now passes Unicode objects to the file's write
1518 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001519 of a print statement must support Unicode objects, i.e. they must
1520 at least convert them into ASCII strings.
1521
Guido van Rossum624c8af2001-09-18 15:21:04 +00001522- Thread scheduling on Solaris should be improved; it is no longer
1523 necessary to insert a small sleep at the start of a thread in order
1524 to let other runnable threads be scheduled.
1525
Tim Petersb07352e2001-09-08 01:25:47 +00001526Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001527-------
Tim Petersb07352e2001-09-08 01:25:47 +00001528
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001529- StringIO.StringIO instances and cStringIO.StringIO instances support
1530 read character buffer compatible objects for their .write() methods.
1531 These objects are converted to strings and then handled as such
1532 by the instances.
1533
Barry Warsaw2f600732001-09-24 04:28:10 +00001534- The "email" package has been added. This is basically a port of the
1535 mimelib package <http://sf.net/projects/mimelib> with API changes
1536 and some implementations updated to use iterators and generators.
1537
Tim Peters8a9c2842001-09-22 21:30:22 +00001538- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1539 restores the ability of Tools/scripts/ndiff.py to start producing output
1540 before the entire comparison is complete.
1541
Barry Warsaw58b072d2001-09-22 04:44:21 +00001542- StringIO.StringIO instances and cStringIO.StringIO instances support
1543 iteration just like file objects (i.e. their .readline() method is
1544 called for each iteration until it returns an empty string).
1545
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001546- The codecs module has grown four new helper APIs to access
1547 builtin codecs: getencoder(), getdecoder(), getreader(),
1548 getwriter().
1549
Guido van Rossum624c8af2001-09-18 15:21:04 +00001550- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1551 simplifies writing XML RPC servers.
1552
Barry Warsaw647d5e82001-09-28 17:01:02 +00001553- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001554 after interpretation of symbolic links. On non-Unix systems, this
1555 is an alias for os.path.abspath().
1556
Tim Peters16a77ad2001-09-08 04:00:12 +00001557- operator.indexOf() (PySequence_Index() in the C API) now works with any
1558 iterable object.
1559
Guido van Rossum624c8af2001-09-18 15:21:04 +00001560- smtplib now supports various authentication and security features of
1561 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001562
Guido van Rossum624c8af2001-09-18 15:21:04 +00001563- hmac: a new module implementing keyed hashing for message
1564 authentication.
1565
1566- mimetypes now recognizes more extensions and file types. At the
1567 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001568
Guido van Rossum624c8af2001-09-18 15:21:04 +00001569- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001570 Python 2.2 bytecode generation. It has also been promoted from a
1571 Tool to a standard library package. (Tools/compiler still exists as
1572 a sample driver.)
1573
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001574Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001575-----
Guido van Rossum624c8af2001-09-18 15:21:04 +00001576
Tim Petersb07352e2001-09-08 01:25:47 +00001577Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001578-----
Tim Petersb07352e2001-09-08 01:25:47 +00001579
Guido van Rossum624c8af2001-09-18 15:21:04 +00001580- Large file support (LFS) is now automatic when the platform supports
1581 it; no more manual configuration tweaks are needed. On Linux, at
1582 least, it's possible to have a system whose C library supports large
1583 files but whose kernel doesn't; in this case, large file support is
1584 still enabled but doesn't do you any good unless you upgrade your
1585 kernel or share your Python executable with another system whose
1586 kernel has large file support.
1587
1588- The configure script now supplies plausible defaults in a
1589 cross-compilation environment. This doesn't mean that the supplied
1590 values are always correct, or that cross-compilation now works
1591 flawlessly -- but it's a first step (and it shuts up most of
1592 autoconf's warnings about AC_TRY_RUN).
1593
1594- The Unix build is now a bit less chatty, courtesy of the parser
1595 generator. The build is completely silent (except for errors) when
1596 using "make -s", thanks to a -q option to setup.py.
1597
Tim Petersb07352e2001-09-08 01:25:47 +00001598C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001599-----
Tim Petersb07352e2001-09-08 01:25:47 +00001600
Guido van Rossum624c8af2001-09-18 15:21:04 +00001601- The "structmember" API now supports some new flag bits to deny read
1602 and/or write access to attributes in restricted execution mode.
1603
Tim Petersb07352e2001-09-08 01:25:47 +00001604New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001605-------------
Tim Petersb07352e2001-09-08 01:25:47 +00001606
Guido van Rossum624c8af2001-09-18 15:21:04 +00001607- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1608 (http://familiar.handhelds.org).
1609
Tim Petersb07352e2001-09-08 01:25:47 +00001610Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001611-----
Tim Petersb07352e2001-09-08 01:25:47 +00001612
Tim Peters8a9c2842001-09-22 21:30:22 +00001613- The "classic" standard tests, which work by comparing stdout to
1614 an expected-output file under Lib/test/output/, no longer stop at
1615 the first mismatch. Instead the test is run to completion, and a
1616 variant of ndiff-style comparison is used to report all differences.
1617 This is much easier to understand than the previous style of reporting.
1618
1619- The unittest-based standard tests now use regrtest's test_main()
1620 convention, instead of running as a side-effect of merely being
1621 imported. This allows these tests to be run in more natural and
1622 flexible ways as unittests, outside the regrtest framework.
1623
1624- regrtest.py is much better integrated with unittest and doctest now,
1625 especially in regard to reporting errors.
1626
Tim Petersb07352e2001-09-08 01:25:47 +00001627Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001628-------
Tim Petersb07352e2001-09-08 01:25:47 +00001629
Guido van Rossum624c8af2001-09-18 15:21:04 +00001630- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001631 that support it (NTFS under Windows 2000). See "What's New in
1632 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001633
Tim Petersb07352e2001-09-08 01:25:47 +00001634
Tim Petersedc99312001-08-22 21:36:50 +00001635What's New in Python 2.2a3?
1636===========================
1637
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001638*Release Date: 07-Sep-2001*
1639
Tim Petersedc99312001-08-22 21:36:50 +00001640Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001641----
Tim Petersedc99312001-08-22 21:36:50 +00001642
Tim Peters9fffa3e2001-09-04 05:14:19 +00001643- Conversion of long to float now raises OverflowError if the long is too
1644 big to represent as a C double.
1645
Tim Peters32f453e2001-09-03 08:35:41 +00001646- The 3-argument builtin pow() no longer allows a third non-None argument
1647 if either of the first two arguments is a float, or if both are of
1648 integer types and the second argument is negative (in which latter case
1649 the arguments are converted to float, so this is really the same
1650 restriction).
1651
Tim Peters5d2b77c2001-09-03 05:47:38 +00001652- The builtin dir() now returns more information, and sometimes much
1653 more, generally naming all attributes of an object, and all attributes
1654 reachable from the object via its class, and from its class's base
1655 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1656 an empty list. In 2.2a3,
1657
1658 >>> dir([])
1659 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1660 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1661 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1662 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1663 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1664 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1665 'reverse', 'sort']
1666
1667 dir(module) continues to return only the module's attributes, though.
1668
Tim Petersbdee63f2001-09-02 03:40:59 +00001669- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001670 than raising OverflowError. This is a partial implementation of PEP
1671 237. You can use -Wdefault::OverflowWarning to enable a warning for
1672 this situation, and -Werror::OverflowWarning to revert to the old
1673 OverflowError exception.
1674
Guido van Rossum61c345f2001-09-04 03:26:15 +00001675- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001676 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001677 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1678 -Qold, meaning the / operator has its classic meaning and no
1679 warnings are issued. Using -Qwarn issues a run-time warning about
1680 all uses of classic division for int and long arguments; -Qwarnall
1681 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001682 (for use with fixdiv.py).
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001683 [Note: the remainder of this item (preserved below) became
1684 obsolete in 2.2c1 -- -Qnew has global effect in 2.2] ::
1685
1686 Using -Qnew is questionable; it turns on new division by default, but
1687 only in the __main__ module. You can usefully combine -Qwarn or
1688 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1689 warns about classic division everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +00001690
Tim Petersbdee63f2001-09-02 03:40:59 +00001691- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001692 long, float, str, unicode, and tuple. (The types complex, list and
1693 dictionary can also be subclassed; this was introduced earlier.)
1694 Note that restrictions apply when subclassing immutable built-in
1695 types: you can only affect the value of the instance by overloading
1696 __new__. You can add mutable attributes, and the subclass instances
1697 will have a __dict__ attribute, but you cannot change the "value"
1698 (as implemented by the base class) of an immutable subclass instance
1699 once it is created.
1700
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001701- The dictionary constructor now takes an optional argument, a
1702 mapping-like object, and initializes the dictionary from its
1703 (key, value) pairs.
1704
Tim Petersbdee63f2001-09-02 03:40:59 +00001705- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001706 "cooperative super calls" in a multiple inheritance setting. For an
1707 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1708
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001709- A new built-in type, property, has been added. This enables the
1710 creation of "properties". These are attributes implemented by
1711 getter and setter functions (or only one of these for read-only or
1712 write-only attributes), without the need to override __getattr__.
1713 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001714
Tim Petersbdee63f2001-09-02 03:40:59 +00001715- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001716 liberalized, to allow leading zeroes. Examples of literals now
1717 legal that were SyntaxErrors before:
1718
1719 00.0 0e3 0100j 07.5 00000000000000000008.
1720
Tim Petersbdee63f2001-09-02 03:40:59 +00001721- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001722 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1723
Tim Petersedc99312001-08-22 21:36:50 +00001724Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001725-------
Tim Petersedc99312001-08-22 21:36:50 +00001726
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001727- telnetlib includes symbolic names for the options, and support for
Martin v. Löwis1da9c572002-11-04 09:56:00 +00001728 setting an option negotiation callback. It also supports processing
1729 of suboptions.
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001730
Tim Petersa40c7932001-09-05 22:36:56 +00001731- The new C standard no longer requires that math libraries set errno to
1732 ERANGE on overflow. For platform libraries that exploit this new
1733 freedom, Python's overflow-checking was wholly broken. A new overflow-
1734 checking scheme attempts to repair that, but may not be reliable on all
1735 platforms (C doesn't seem to provide anything both useful and portable
1736 in this area anymore).
1737
Martin v. Löwis44f86962001-09-05 13:44:54 +00001738- Asynchronous timeout actions are available through the new class
1739 threading.Timer.
1740
Tim Peters78526162001-09-05 00:53:45 +00001741- math.log and math.log10 now return sensible results for even huge
1742 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1743
Tim Petersbdee63f2001-09-02 03:40:59 +00001744- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001745 currently held. See the docs for the imp module.
1746
Tim Petersbdee63f2001-09-02 03:40:59 +00001747- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001748 dumps containing ints written on platforms where Python ints are 8 bytes.
1749 When read on a box where Python ints are 4 bytes, such values are
1750 converted to Python longs.
1751
Tim Petersbdee63f2001-09-02 03:40:59 +00001752- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001753 code objects is no longer allowed. This plugs a security hole.
1754
Steve Purcell6091cd62001-09-06 16:05:17 +00001755- unittest.TestResult instances no longer store references to tracebacks
1756 generated by test failures. This prevents unexpected dangling references
1757 to objects that should be garbage collected between tests.
1758
Tim Petersedc99312001-08-22 21:36:50 +00001759Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001760-----
Tim Petersedc99312001-08-22 21:36:50 +00001761
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001762- Tools/scripts/fixdiv.py has been added which can be used to fix
1763 division operators as per PEP 238.
1764
Tim Petersedc99312001-08-22 21:36:50 +00001765Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001766-----
Tim Petersedc99312001-08-22 21:36:50 +00001767
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001768- If you are an adventurous person using Mac OS X you may want to look at
1769 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1770 application, which can be used for experimenting with Carbon or Cocoa.
1771 Discussion of this on pythonmac-sig, please.
1772
Tim Peters7eea37e2001-09-04 22:08:56 +00001773C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001774-----
Tim Peters7eea37e2001-09-04 22:08:56 +00001775
1776- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001777
Tim Peters9fffa3e2001-09-04 05:14:19 +00001778- Note that PyLong_AsDouble can fail! This has always been true, but no
1779 callers checked for it. It's more likely to fail now, because overflow
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001780 errors are properly detected now. The proper way to check::
Tim Peters9fffa3e2001-09-04 05:14:19 +00001781
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001782 double x = PyLong_AsDouble(some_long_object);
1783 if (x == -1.0 && PyErr_Occurred()) {
1784 /* The conversion failed. */
1785 }
Tim Peters9fffa3e2001-09-04 05:14:19 +00001786
Tim Petersbdee63f2001-09-02 03:40:59 +00001787- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001788 compile but will not participate in GC. To upgrade an extension
1789 module:
1790
1791 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001792
Neil Schemenauer4042c692001-08-30 15:38:01 +00001793 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1794 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001795
Neil Schemenauer4042c692001-08-30 15:38:01 +00001796 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1797 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001798
Neil Schemenauer4042c692001-08-30 15:38:01 +00001799 - remove PyGC_HEAD_SIZE from object size calculations
1800
1801 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1802
Tim Petersbdee63f2001-09-02 03:40:59 +00001803- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001804 These can be used safely to construct string objects from a
1805 sprintf-style format string (similar to the format string supported
1806 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001807
Tim Petersedc99312001-08-22 21:36:50 +00001808New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001809-------------
Tim Petersedc99312001-08-22 21:36:50 +00001810
Tim Petersb7da0902001-09-02 23:01:43 +00001811- Stephen Hansen contributed patches sufficient to get a clean compile
1812 under Borland C (Windows), but he reports problems running it and ran
1813 out of time to complete the port. Volunteers? Expect a MemoryError
1814 when importing the types module; this is probably shallow, and
1815 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001816
Tim Petersedc99312001-08-22 21:36:50 +00001817Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001818-----
Tim Petersedc99312001-08-22 21:36:50 +00001819
1820Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001821-------
Tim Petersedc99312001-08-22 21:36:50 +00001822
Tim Peters6e13a562001-09-06 00:32:15 +00001823- Large file support is now enabled on Win32 platforms as well as on
1824 Win64. This means that, for example, you can use f.tell() and f.seek()
1825 to manipulate files larger than 2 gigabytes (provided you have enough
1826 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001827 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1828 filesize limit, and large file support makes no difference there.
1829 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1830 NTFS has no practical limit on file size, and files of any size can be
1831 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001832
Tim Petersbdee63f2001-09-02 03:40:59 +00001833- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001834 points to command.com (patch from Brian Quinlan).
1835
Tim Petersedc99312001-08-22 21:36:50 +00001836
Tim Peters20f51a72001-07-21 02:31:40 +00001837What's New in Python 2.2a2?
1838===========================
1839
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001840*Release Date: 22-Aug-2001*
1841
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001842Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001843-----
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001844
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001845- Tim Peters developed a brand new Windows installer using Wise 8.1,
1846 generously donated to us by Wise Solutions.
1847
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001848- configure supports a new option --enable-unicode, with the values
1849 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1850 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001851
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001852- A new configure option --enable-framework builds a Mac OS X framework,
1853 which "make frameworkinstall" will install. This provides a starting
1854 point for more mac-like functionality, join pythonmac-sig@python.org
1855 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001856
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001857- The NeXT platform is no longer supported.
1858
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001859- The 'new' module is now statically linked.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001860
Tim Peters0afb6092001-08-15 06:06:44 +00001861Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001862-----
Tim Peters0afb6092001-08-15 06:06:44 +00001863
1864- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001865 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001866 the module docstring for details.
1867
Tim Peters20f51a72001-07-21 02:31:40 +00001868Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001869-----
Tim Peters20f51a72001-07-21 02:31:40 +00001870
Tim Peters5e824c32001-08-12 22:25:01 +00001871- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001872 platforms, allowing to give clearer test result output. regrtest
1873 also has optional --use/-u switch to run normally disabled tests
1874 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001875
Tim Peters20f51a72001-07-21 02:31:40 +00001876- Several new tests in the standard test suite, with special thanks to
1877 Nick Mathewson.
1878
1879Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001880----
Tim Peters20f51a72001-07-21 02:31:40 +00001881
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001882- The floor division operator // has been added as outlined in PEP
1883 238. The / operator still provides classic division (and will until
1884 Python 3.0) unless "from __future__ import division" is included, in
1885 which case the / operator will provide true division. The operator
1886 module provides truediv() and floordiv() functions. Augmented
1887 assignment variants are included, as are the equivalent overloadable
1888 methods and C API methods. See the PEP for a full discussion:
1889 <http://python.sf.net/peps/pep-0238.html>
1890
Tim Peters6cd6a822001-08-17 22:11:27 +00001891- Future statements are now effective in simulated interactive shells
1892 (like IDLE). This should "just work" by magic, but read Michael
1893 Hudson's "Future statements in simulated shells" PEP 264 for full
1894 details: <http://python.sf.net/peps/pep-0264.html>.
1895
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001896- The type/class unification (PEP 252-253) was integrated into the
1897 trunk and is not so tentative any more (the exact specification of
1898 some features is still tentative). A lot of work has done on fixing
1899 bugs and adding robustness and features (performance still has to
1900 come a long way).
1901
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001902- Warnings about a mismatch in the Python API during extension import
1903 now use the Python warning framework (which makes it possible to
1904 write filters for these warnings).
1905
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001906- A function's __dict__ (aka func_dict) will now always be a
1907 dictionary. It used to be possible to delete it or set it to None,
1908 but now both actions raise TypeErrors. It is still legal to set it
1909 to a dictionary object. Getting func.__dict__ before any attributes
1910 have been assigned now returns an empty dictionary instead of None.
1911
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001912- A new command line option, -E, was added which disables the use of
1913 all environment variables, or at least those that are specifically
1914 significant to Python. Usually those have a name starting with
1915 "PYTHON". This was used to fix a problem where the tests fail if
1916 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1917 older distribution.
1918
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001919Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001920-------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001921
Tim Peters5e824c32001-08-12 22:25:01 +00001922- New class Differ and new functions ndiff() and restore() in difflib.py.
1923 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001924 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001925
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001926- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1927 value using the minimal quoting required for the value; more
1928 reliable than using xml.sax.saxutils.escape() for attribute values.
1929
1930- Readline completion support for cmd.Cmd was added.
1931
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001932- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1933
1934- Added function threading.BoundedSemaphore()
1935
1936- Added Ka-Ping Yee's cgitb.py module.
1937
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001938- The 'new' module now exposes the CO_xxx flags.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001939
Martin v. Löwis560da622001-11-24 09:24:51 +00001940- The gc module offers the get_referents function.
1941
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001942New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001943-------------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001944
1945C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001946-----
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001947
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001948- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1949 which provide a cross-platform implementations for the
1950 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1951 the standard sprintf() and vsprintf() C lib APIs, these versions
1952 apply bounds checking on the used buffer which enhances protection
1953 against buffer overruns.
1954
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001955- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001956 and extensions using different Unicode widths is rendered next to
1957 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001958 will result in an ImportError. Unicode extensions writers must make
1959 sure to check the Unicode width compatibility in their extensions by
1960 using at least one of the mangled Unicode APIs in the extension.
1961
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001962- Two new flags METH_NOARGS and METH_O are available in method definition
1963 tables to simplify implementation of methods with no arguments and a
1964 single untyped argument. Calling such methods is more efficient than
1965 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1966 deprecated.
1967
Tim Petersc1731372001-08-04 08:12:36 +00001968Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001969-------
Tim Petersc1731372001-08-04 08:12:36 +00001970
1971- "import module" now compiles module.pyw if it exists and nothing else
1972 relevant is found.
1973
Tim Peters20f51a72001-07-21 02:31:40 +00001974
Guido van Rossum55a78992001-07-17 17:22:32 +00001975What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +00001976===========================
1977
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001978*Release date: 18-Jul-2001*
1979
Tim Petersf553f892001-05-01 20:45:31 +00001980Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001981----
Tim Petersa814db52001-05-14 07:05:58 +00001982
Tim Peters6d6c1a32001-08-02 04:15:00 +00001983- TENTATIVELY, a large amount of code implementing much of what's
1984 described in PEP 252 (Making Types Look More Like Classes) and PEP
1985 253 (Subtyping Built-in Types) was added. This will be released
1986 with Python 2.2a1. Documentation will be provided separately
1987 through http://www.python.org/2.2/. The purpose of releasing this
1988 with Python 2.2a1 is to test backwards compatibility. It is
1989 possible, though not likely, that a decision is made not to release
1990 this code as part of 2.2 final, if any serious backwards
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00001991 incompatibilities are found during alpha testing that cannot be
Tim Peters6d6c1a32001-08-02 04:15:00 +00001992 repaired.
1993
Guido van Rossum55a78992001-07-17 17:22:32 +00001994- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001995 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001996 more 'yield' statements. See PEP 255. Since this adds a new
1997 keyword to the language, this feature must be enabled by including a
1998 future statement: "from __future__ import generators" (see PEP 236).
1999 Generators will become a standard feature in a future release
2000 (probably 2.3). Without this future statement, 'yield' remains an
2001 ordinary identifier, but a warning is issued each time it is used.
2002 (These warnings currently don't conform to the warnings framework of
2003 PEP 230; we intend to fix this in 2.2a2.)
2004
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00002005- The UTF-16 codec was modified to be more RFC compliant. It will now
2006 only remove BOM characters at the start of the string and then
2007 only if running in native mode (UTF-16-LE and -BE won't remove a
2008 leading BMO character).
2009
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00002010- Strings now have a new method .decode() to complement the already
2011 existing .encode() method. These two methods provide direct access
2012 to the corresponding decoders and encoders of the registered codecs.
2013
2014 To enhance the usability of the .encode() method, the special
2015 casing of Unicode object return values was dropped (Unicode objects
2016 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00002017
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00002018 Both methods will now return whatever the codec in charge of the
2019 requested encoding returns as object, e.g. Unicode codecs will
2020 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
2021 will return u"äöü"). This enables codec writer to create codecs
2022 for various simple to use conversions.
2023
2024 New codecs were added to demonstrate these new features (the .encode()
2025 and .decode() columns indicate the type of the returned objects):
2026
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002027 +---------+-----------+-----------+-----------------------------+
2028 |Name | .encode() | .decode() | Description |
2029 +=========+===========+===========+=============================+
2030 |uu | string | string | UU codec (e.g. for email) |
2031 +---------+-----------+-----------+-----------------------------+
2032 |base64 | string | string | base64 codec |
2033 +---------+-----------+-----------+-----------------------------+
2034 |quopri | string | string | quoted-printable codec |
2035 +---------+-----------+-----------+-----------------------------+
2036 |zlib | string | string | zlib compression |
2037 +---------+-----------+-----------+-----------------------------+
2038 |hex | string | string | 2-byte hex codec |
2039 +---------+-----------+-----------+-----------------------------+
2040 |rot-13 | string | Unicode | ROT-13 Unicode charmap codec|
2041 +---------+-----------+-----------+-----------------------------+
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00002042
Mark Hammond2a0af792001-05-14 03:09:36 +00002043- Some operating systems now support the concept of a default Unicode
2044 encoding for file system operations. Notably, Windows supports 'mbcs'
2045 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00002046 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00002047 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00002048
2049 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00002050 functions that return filenames (such as os.listdir()) to return Python
2051 string objects pre-encoded using the default file system encoding for
2052 the platform. As this encoding is likely to be different from Python's
2053 default encoding, converting this name to a Unicode object before passing
2054 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00002055 would attempt to use its default encoding (generally ASCII) rather than
2056 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00002057
Tim Petersa814db52001-05-14 07:05:58 +00002058 In general, this change simply removes surprises when working with
2059 Unicode and the file system, making these operations work as you expect,
2060 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00002061 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00002062
Tim Peters61dff2b2001-05-08 15:43:37 +00002063- Float (and complex) literals in source code were evaluated to full
2064 precision only when running from a .py file; the same code loaded from a
2065 .pyc (or .pyo) file could suffer numeric differences starting at about the
2066 12th significant decimal digit. For example, on a machine with IEEE-754
2067 floating arithmetic,
2068
2069 x = 9007199254740992.0
2070 print long(x)
2071
2072 printed 9007199254740992 if run directly from .py, but 9007199254740000
2073 if from a compiled (.pyc or .pyo) file. This was due to marshal using
2074 str(float) instead of repr(float) when building code objects. marshal
2075 now uses repr(float) instead, which should reproduce floats to full
2076 machine precision (assuming the platform C float<->string I/O conversion
2077 functions are of good quality).
2078
2079 This may cause floating-point results to change in some cases, and
2080 usually for the better, but may also cause numerically unstable
2081 algorithms to break.
2082
Tim Peters2f228e72001-05-13 00:19:31 +00002083- The implementation of dicts suffers fewer collisions, which has speed
2084 benefits. However, the order in which dict entries appear in dict.keys(),
2085 dict.values() and dict.items() may differ from previous releases for a
2086 given dict. Nothing is defined about this order, so no program should
2087 rely on it. Nevertheless, it's easy to write test cases that rely on the
2088 order by accident, typically because of printing the str() or repr() of a
2089 dict to an "expected results" file. See Lib/test/test_support.py's new
2090 sortdict(dict) function for a simple way to display a dict in sorted
2091 order.
2092
Tim Peters7a3bfc32001-06-12 01:22:22 +00002093- Many other small changes to dicts were made, resulting in faster
2094 operation along the most common code paths.
2095
Guido van Rossum10315822001-05-01 20:54:30 +00002096- Dictionary objects now support the "in" operator: "x in dict" means
2097 the same as dict.has_key(x).
2098
Barry Warsaw51acc8d2001-06-26 20:12:50 +00002099- The update() method of dictionaries now accepts generic mapping
2100 objects. Specifically the argument object must support the .keys()
2101 and __getitem__() methods. This allows you to say, for example,
2102 {}.update(UserDict())
2103
Guido van Rossum10315822001-05-01 20:54:30 +00002104- Iterators were added; this is a generalized way of providing values
2105 to a for loop. See PEP 234. There's a new built-in function iter()
2106 to return an iterator. There's a new protocol to get the next value
2107 from an iterator using the next() method (in Python) or the
2108 tp_iternext slot (in C). There's a new protocol to get iterators
2109 using the __iter__() method (in Python) or the tp_iter slot (in C).
2110 Iterating (i.e. a for loop) over a dictionary generates its keys.
2111 Iterating over a file generates its lines.
2112
Tim Petersf553f892001-05-01 20:45:31 +00002113- The following functions were generalized to work nicely with iterator
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00002114 arguments::
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002115
Tim Peterse63415e2001-05-08 04:38:29 +00002116 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00002117 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
2118 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00002119 join() method of strings
2120 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00002121 'x in y' and 'x not in y' (PySequence_Contains() in C API)
2122 operator.countOf() (PySequence_Count() in C API)
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002123 right-hand side of assignment statements with multiple targets, such as ::
Tim Petersd6d010b2001-06-21 02:49:55 +00002124 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00002125
Tim Petersd85e1022001-05-11 21:51:48 +00002126- Accessing module attributes is significantly faster (for example,
2127 random.random or os.path or yourPythonModule.yourAttribute).
2128
Tim Peterse63415e2001-05-08 04:38:29 +00002129- Comparing dictionary objects via == and != is faster, and now works even
2130 if the keys and values don't support comparisons other than ==.
2131
Tim Peters95bf9392001-05-10 08:32:44 +00002132- Comparing dictionaries in ways other than == and != is slower: there were
2133 insecurities in the dict comparison implementation that could cause Python
2134 to crash if the element comparison routines for the dict keys and/or
2135 values mutated the dicts. Making the code bulletproof slowed it down.
2136
Tim Peterseb28ef22001-06-02 05:27:19 +00002137- Collisions in dicts are resolved via a new approach, which can help
2138 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00002139 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00002140 faster now. Thanks to Christian Tismer for pointing out the cause and
2141 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00002142
Tim Peters52e155e2001-06-16 05:42:57 +00002143- repr() is much faster for large containers (dict, list, tuple).
2144
2145
Tim Petersa814db52001-05-14 07:05:58 +00002146Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002147-------
Tim Petersa814db52001-05-14 07:05:58 +00002148
Fred Drake960fdf92001-07-20 18:38:26 +00002149- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002150 were added to the string module. These a locale-independent
Fred Drake960fdf92001-07-20 18:38:26 +00002151 constants, unlike letters, lowercase, and uppercase. These are now
2152 use in appropriate locations in the standard library.
2153
Martin v. Löwisf0473d52001-07-18 16:17:16 +00002154- The flags used in dlopen calls can now be configured using
2155 sys.setdlopenflags and queried using sys.getdlopenflags.
2156
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00002157- Fredrik Lundh's xmlrpclib is now a standard library module. This
2158 provides full client-side XML-RPC support. In addition,
2159 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
2160 one asyncore-based). Thanks to Eric Raymond for the documentation.
2161
Guido van Rossum643d3912001-07-05 14:46:25 +00002162- The xrange() object is simplified: it no longer supports slicing,
2163 repetition, comparisons, efficient 'in' checking, the tolist()
2164 method, or the start, stop and step attributes. See PEP 260.
2165
Martin v. Löwisebf94db2001-06-06 06:25:40 +00002166- A new function fnmatch.filter to filter lists of file names was added.
2167
Barry Warsawffd674d2001-05-22 16:00:10 +00002168- calendar.py uses month and day names based on the current locale.
2169
Guido van Rossum2e0a6542001-05-15 02:14:44 +00002170- strop is now *really* obsolete (this was announced before with 1.6),
2171 and issues DeprecationWarning when used (except for the four items
2172 that are still imported into string.py).
2173
Tim Petersa814db52001-05-14 07:05:58 +00002174- Cookie.py now sorts key+value pairs by key in output strings.
2175
2176- pprint.isrecursive(object) didn't correctly identify recursive objects.
2177 Now it does.
2178
Tim Peters95b3f782001-05-14 18:39:41 +00002179- pprint functions now much faster for large containers (tuple, list, dict).
2180
Tim Peters7b9542a2001-06-10 23:40:19 +00002181- New 'q' and 'Q' format codes in the struct module, corresponding to C
2182 types "long long" and "unsigned long long" (on Windows, __int64). In
2183 native mode, these can be used only when the platform C compiler supports
2184 these types (when HAVE_LONG_LONG is #define'd by the Python config
2185 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00002186 In standard mode, 'q' and 'Q' are supported on all platforms, and are
2187 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00002188
Guido van Rossum83213cc2001-06-12 16:48:52 +00002189- The site module installs a new built-in function 'help' that invokes
2190 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
2191 it displays a message reminding the user to use 'help()' or
2192 'help(object)'.
2193
Tim Petersa814db52001-05-14 07:05:58 +00002194Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002195-----
Tim Petersa814db52001-05-14 07:05:58 +00002196
2197- New test_mutants.py runs dict comparisons where the key and value
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002198 comparison operators mutate the dicts randomly during comparison. This
Tim Petersa814db52001-05-14 07:05:58 +00002199 rapidly causes Python to crash under earlier releases (not for the faint
2200 of heart: it can also cause Win9x to freeze or reboot!).
2201
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002202- New test_pprint.py verifies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00002203 pprint.isreadable() return sensible results. Also verifies that simple
2204 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00002205
Tim Peters4324aa32001-05-28 22:30:08 +00002206C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002207-----
Tim Peters4324aa32001-05-28 22:30:08 +00002208
2209- Removed the unused last_is_sticky argument from the internal
2210 _PyTuple_Resize(). If this affects you, you were cheating.
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002211
2212----
2213
2214**(For information about older versions, consult the HISTORY file.)**