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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
Guido van Rossumba602972002-10-01 18:18:58 +0000295- The _tkinter module (and hence Tkinter) has dropped support for
296 Tcl/Tk 8.0 and 8.1. Only Tcl/Tk versions 8.2, 8.3 and 8.4 are
297 supported.
298
Martin v. Löwis658009a2002-09-16 17:26:24 +0000299- cPickle.BadPickleGet is now a class.
300
Martin v. Löwisa32c9942002-09-09 16:17:47 +0000301- The time stamps in os.stat_result are floating point numbers now.
Martin v. Löwis94717ed2002-09-09 14:24:16 +0000302
Neal Norwitzb5673922002-09-05 21:48:07 +0000303- If the size passed to mmap.mmap() is larger than the length of the
304 file on non-Windows platforms, a ValueError is raised. [SF bug 585792]
305
Guido van Rossumb57089c2002-08-06 16:20:26 +0000306- The xreadlines module is slated for obsolescence.
307
Guido van Rossum79f0a102002-07-23 03:32:08 +0000308- The strptime function in the time module is now always available (a
309 Python implementation is used when the C library doesn't define it).
310
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000311- The 'new' module is no longer an extension, but a Python module that
312 only exists for backwards compatibility. Its contents are no longer
313 functions but callable type objects.
314
Tim Peters81b92512002-04-29 01:37:32 +0000315- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000316 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000317 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000318
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000319- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
320 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000321
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000322- The locale module now exposes the C library's gettext interface.
323
Tim Petersfbf74f22002-03-14 19:06:01 +0000324- A security hole ("double free") was found in zlib-1.1.3, a popular
325 third party compression library used by some Python modules. The
326 hole was quickly plugged in zlib-1.1.4, and the Windows build of
327 Python now ships with zlib-1.1.4.
328
Martin v. Löwis688357e2002-04-08 21:28:20 +0000329- pwd, grp, and resource return enhanced tuples now, with symbolic
330 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000331
Martin v. Löwis99866332002-03-01 10:27:01 +0000332- array.array is now a type object. A new format character
333 'u' indicates Py_UNICODE arrays. For those, .tounicode and
334 .fromunicode methods are available. Arrays now support __iadd__
335 and __imul__.
336
Neal Norwitze790eae2002-01-01 21:14:12 +0000337- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000338 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
339 is called.
340
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000341- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
342 been added where available.
343
Skip Montanaro8e790e72002-09-03 13:25:17 +0000344- The sys module acquired a new attribute, api_version, which evaluates
345 to the value of the PYTHON_API_VERSION macro with which the
346 interpreter was compiled.
347
Tim Petersaf8446f2001-12-21 21:36:50 +0000348Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000349-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000350
Martin v. Löwise9ce0b02002-10-07 13:23:24 +0000351- shutil.move was added. shutil.copytree now reports errors as an
352 exception at the end, instead of printing error messages.
353
Marc-André Lemburg97047e22002-10-04 11:55:21 +0000354- Encoding name normalization was generalized to not only
355 replace hyphens with underscores, but also all other non-alphanumeric
356 characters (with the exception of the dot which is used for Python
357 package names during lookup). The aliases.py mapping was updated
358 to the new standard.
359
Walter Dörwald5ccaf8f2002-09-06 16:15:58 +0000360- mimetypes has two new functions: guess_all_extensions() which
361 returns a list of all known extensions for a mime type, and
362 add_type() which adds one mapping between a mime type and
363 an extension to the database.
364
Guido van Rossumd8ab35c2002-08-19 16:25:46 +0000365- New module: sets, defines the class Set that implements a mutable
366 set type using the keys of a dict to represent the set. There's
367 also a class ImmutableSet which is useful when you need sets of sets
368 or when you need to use sets as dict keys, and a class BaseSet which
369 is the base class of the two. (This is not documented yet, but
370 help(sets) gives a wealth of information.)
371
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +0000372- Added operator.pow(a,b) which is equivalent to a**b.
373
Tim Peters012c0a32002-08-16 03:40:07 +0000374- random.randrange(-sys.maxint-1, sys.maxint) no longer raises
375 OverflowError. That is, it now accepts any combination of 'start'
376 and 'stop' arguments so long as each is in the range of Python's
377 bounded integers.
378
Guido van Rossum4a57c332002-08-02 18:05:20 +0000379- New "algorithms" module: heapq, implements a heap queue. Thanks to
380 Kevin O'Connor for the code and François Pinard for an entertaining
381 write-up explaining the theory and practical uses of heaps.
382
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000383- New encoding for the Palm OS character set: palmos.
384
Tim Peters943382c2002-07-07 03:59:34 +0000385- binascii.crc32() and the zipfile module had problems on some 64-bit
386 platforms. These have been fixed. On a platform with 8-byte C longs,
387 crc32() now returns a signed-extended 4-byte result, so that its value
388 as a Python int is equal to the value computed a 32-bit platform.
389
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000390- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
391 argument.
392
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000393- Some fixes in the copy module: when an object is copied through its
394 __reduce__ method, there was no check for a __setstate__ method on
395 the result [SF patch 565085]; deepcopy should treat instances of
396 custom metaclasses the same way it treats instances of type 'type'
397 [SF patch 560794].
398
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000399- Sockets now support timeout mode. After s.settimeout(T), where T is
400 a float expressing seconds, subsequent operations raise an exception
401 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000402 mode, use s.settimeout(None). There's also a module function,
403 socket.setdefaulttimeout(T), which sets the default for all sockets
404 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000405
406- getopt.gnu_getopt was added. This supports GNU-style option
407 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000408
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000409- Stop using strings for exceptions. String objects used for
410 exceptions are now classes deriving from Exception. The objects
411 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
412 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000413
Walter Dörwald474458d2002-06-04 15:16:29 +0000414- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
415 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
416 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
417 big endian systems were added to the codecs module. The old names
418 BOM32_* and BOM64_* were off by a factor of 2.
419
Guido van Rossumf9257822002-06-18 20:43:18 +0000420- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000421
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000422- ftplib.retrlines() now tests for callback is None rather than testing
423 for False. Was causing an error when given a callback object which
424 was callable but also returned len() as zero. The change may
425 create new breakage if the caller relied on the undocumented behavior
426 and called with callback set to [] or some other False value not
427 identical to None.
428
Tim Peters46c04e12002-05-05 20:40:00 +0000429- random.gauss() uses a piece of hidden state used by nothing else,
430 and the .seed() and .whseed() methods failed to reset it. In other
431 words, setting the seed didn't completely determine the sequence of
432 results produced by random.gauss(). It does now. Programs repeatedly
433 mixing calls to a seed method with calls to gauss() may see different
434 results now.
435
Fred Drake7f781c92002-05-01 20:33:53 +0000436- The pickle.Pickler class grew a clear_memo() method to mimic that
437 provided by cPickle.Pickler.
438
Tim Peters81b92512002-04-29 01:37:32 +0000439- difflib's SequenceMatcher class now does a dynamic analysis of
440 which elements are so frequent as to constitute noise. For
441 comparing files as sequences of lines, this generally works better
442 than the IS_LINE_JUNK function, and function ndiff's linejunk
443 argument defaults to None now as a result. A happy benefit is
444 that SequenceMatcher may run much faster now when applied
445 to large files with many duplicate lines (for example, C program
446 text with lots of repeated "}" and "return NULL;" lines).
447
Guido van Rossum256705b2002-04-23 13:29:43 +0000448- New Text.dump() method in Tkinter module.
449
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000450- New distutils commands for building packagers were added to
451 support pkgtool on Solaris and swinstall on HP-UX.
452
453- distutils now has a new abstract binary packager base class
454 command/bdist_packager, which simplifies writing packagers.
455 This will hopefully provide the missing bits to encourage
456 people to submit more packagers, e.g. for Debian, FreeBSD
457 and other systems.
458
Guido van Rossumf9257822002-06-18 20:43:18 +0000459- The UTF-16, -LE and -BE stream readers now raise a
460 NotImplementedError for all calls to .readline(). Previously, they
461 used to just produce garbage or fail with an encoding error --
462 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 +0000463 work well with these.
464
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000465- compileall now supports quiet operation.
466
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000467- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000468 connections.
469
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000470- socket module: the SSL support was broken out of the main
471 _socket module C helper and placed into a new _ssl helper
472 which now gets imported by socket.py if available and working.
473
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000474- encodings package: added aliases for all supported IANA character
475 sets
476
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000477- ftplib: to safeguard the user's privacy, anonymous login will use
478 "anonymous@" as default password, rather than the real user and host
479 name.
480
Fred Drake36736122002-01-10 13:50:31 +0000481- webbrowser: tightened up the command passed to os.system() so that
482 arbitrary shell code can't be executed because a bogus URL was
483 passed in.
484
Tim Peters11bd9942002-02-01 00:52:29 +0000485- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000486 gettext.find an optional all argument. Translations will now fallback
487 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000488
Martin v. Löwis9668b932002-01-12 11:27:42 +0000489- distutils bdist commands now offer a --skip-build option.
490
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000491- warnings.warn now accepts a Warning instance as first argument.
492
Fred Drakefed7e852002-04-04 19:36:15 +0000493- The xml.sax.expatreader.ExpatParser class will no longer create
494 circular references by using itself as the locator that gets passed
495 to the content handler implementation. [SF bug #535474]
496
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000497- The email.Parser.Parser class now properly parses strings regardless
498 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
499 or CRLF). Also, the Header class's constructor default arguments
500 has changed slightly so that an explicit maxlinelen value is always
501 honored.
502
Tim Petersaf8446f2001-12-21 21:36:50 +0000503Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000504-----------
Tim Petersaf8446f2001-12-21 21:36:50 +0000505
Guido van Rossum923e4ef2002-09-17 20:58:59 +0000506- The SGI demos (Demo/sgi) have been removed. Nobody thought they
507 were interesting any more. (The SGI library modules and extensions
508 are still there; it is believed that at least some of these are
509 still used and useful.)
510
Fred Drake40813b12002-08-05 15:24:19 +0000511- IDLE supports the new encoding declarations (PEP 263); it can also
512 deal with legacy 8-bit files if they use the locale's encoding. It
513 allows non-ASCII strings in the interactive shell and executes them
514 in the locale's encoding.
Martin v. Löwis98ce7b72002-08-05 15:11:26 +0000515
Marc-André Lemburg46260092002-04-04 16:17:11 +0000516- freeze.py now produces binaries which can import shared modules,
517 unlike before when this failed due to missing symbol exports in
518 the generated binary.
519
Tim Petersaf8446f2001-12-21 21:36:50 +0000520Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000521-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000522
Guido van Rossum6b3db552002-09-25 15:02:44 +0000523- The fpectl module is not built by default; it's dangerous or useless
524 except in the hands of experts.
525
Tim Petersf47630f2002-08-01 02:34:51 +0000526- The public Python C API will generally be declared using PyAPI_FUNC
Guido van Rossum6b3db552002-09-25 15:02:44 +0000527 and PyAPI_DATA macros, while Python extension module init functions
528 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
529 are deprecated.
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000530
Tim Petersc6a3ff62002-07-08 22:11:52 +0000531- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
532 get into infinite loops, when a new-style class got garbage-collected.
533 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
534 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
535 COUNT_ALLOCS is not enabled by default, in either release or debug
536 builds, and that new-style classes are immortal only in COUNT_ALLOCS
537 builds.
538
Tim Peters943382c2002-07-07 03:59:34 +0000539- Compiling out the cyclic garbage collector is no longer an option.
540 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
541 that it's always defined (for the benefit of any extension modules
542 that may be conditionalizing on it). A bonus is that any extension
543 type participating in cyclic gc can choose to participate in the
544 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
545 to require editing the core to teach the trashcan mechanism about the
546 new type.
547
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000548- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000549
550 The Standard C macro HUGE_VAL and its float and long double analogs,
551 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
552 positive infinities.
553
554 Python only uses the double HUGE_VAL, and only to #define its own symbol
555 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
556 pyport.h used to try to worm around that, but the workarounds triggered
557 other bugs on other platforms, so we gave up. If your platform defines
558 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
559 that works on your platform. The only instance of this I'm sure about
560 is on an unknown subset of Cray systems, described here:
561
562 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
563
564 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
565
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000566- The configure option --without-doc-strings can be used to remove the
567 doc strings from the builtin functions and modules; this reduces the
568 size of the executable.
569
Guido van Rossumadd88062002-08-15 14:01:14 +0000570- The universal newlines option (PEP 278) is on by default. On Unix
571 it can be disabled by passing --without-universal-newlines to the
572 configure script. On other platforms, remove
573 WITH_UNIVERSAL_NEWLINES from pyconfig.h.
Tim Peters639295f2002-04-21 07:30:30 +0000574
Martin v. Löwis1142de32002-03-29 16:28:31 +0000575- On Unix, a shared libpython2.3.so can be created with --enable-shared.
576
Tim Peters8deda702002-03-30 10:06:07 +0000577- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
578 preprocessor symbols were eliminated. The internal decisions they
579 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000580
Fred Drake7d28b732002-05-02 21:17:00 +0000581- The tools used to build the documentation now work under Cygwin as
582 well as Unix.
583
Skip Montanaro57454e52002-06-14 20:30:31 +0000584- The bsddb and dbm module builds have been changed to try and avoid version
585 skew problems and disable linkage with Berkeley DB 1.85 unless the
586 installer knows what s/he's doing. See the section on building these
587 modules in the README file for details.
588
Tim Petersaf8446f2001-12-21 21:36:50 +0000589C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000590-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000591
Guido van Rossum45ec02a2002-08-19 21:43:18 +0000592- The string object's layout has changed: the pointer member
593 ob_sinterned has been replaced by an int member ob_sstate. On some
594 platforms (e.g. most 64-bit systems) this may change the offset of
595 the ob_sval member, so as a precaution the API_VERSION has been
596 incremented. The apparently unused feature of "indirect interned
597 strings", supported by the ob_sinterned member, is gone. Interned
598 strings are now usually mortal; theres a new API,
599 PyString_InternImmortal() that creates immortal interned strings.
600 (The ob_sstate member can only take three values; however, while
601 making it a char saves a few bytes per string object on average, in
602 it also slowed things down a bit because ob_sval was no longer
603 aligned.)
604
Guido van Rossumfdb86482002-08-14 21:20:32 +0000605- The Py_InitModule*() functions now accept NULL for the 'methods'
606 argument. Modules without global functions are becoming more common
607 now that factories can be types rather than functions.
608
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000609- New C API PyUnicode_FromOrdinal() which exposes unichr() at C
610 level.
611
Thomas Heller085358a2002-07-29 14:27:41 +0000612- New functions PyErr_SetExcFromWindowsErr() and
613 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
614 PyErr_SetFromWindowsErrWithFilename() and
615 PyErr_SetFromWindowsErr(), but they allow to specify
616 the exception type to raise. Available on Windows.
617
Tim Peters7c321a82002-07-09 02:57:01 +0000618- Py_FatalError() is now declared as taking a const char* argument. It
619 was previously declared without const. This should not affect working
620 code.
621
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000622- Added new macro PySequence_ITEM(o, i) that directly calls
623 sq_item without rechecking that o is a sequence and without
624 adjusting for negative indices.
625
Fred Draked0ba6362002-05-02 21:28:26 +0000626- PyRange_New() now raises ValueError if the fourth argument is not 1.
627 This is part of the removal of deprecated features of the xrange
628 object.
629
Guido van Rossum517c7d42002-04-26 02:49:14 +0000630- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
631 coercion if both arguments have the same type but this type has the
632 CHECKTYPES flag set. This is to better support proxies.
633
Skip Montanaroa2a07bc2002-09-30 15:23:01 +0000634- The type of tp_free has been changed from "``void (*)(PyObject *)``" to
635 "``void (*)(void *)``".
Neil Schemenauer9344b142002-04-12 23:00:08 +0000636
637- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
638
Guido van Rossum0986d822002-04-08 01:38:42 +0000639- A type can now inherit its metatype from its base type. Previously,
640 when PyType_Ready() was called, if ob_type was found to be NULL, it
641 was always set to &PyType_Type; now it is set to base->ob_type,
642 where base is tp_base, defaulting to &PyObject_Type.
643
644- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
645
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000646- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000647
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000648- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000649 without going through the buffer API.
650
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000651- The enumerators of cmp_op have been renamed to use the prefix ``PyCmp_``.
Martin v. Löwis7198a522002-01-01 19:59:11 +0000652
Tim Peters10a3bb52001-12-25 19:07:38 +0000653- An old #define of ANY as void has been removed from pyport.h. This
654 hasn't been used since Python's pre-ANSI days, and the #define has
655 been marked as obsolete since then. SF bug 495548 says it created
656 conflicts with other packages, so keeping it around wasn't harmless.
657
Tim Petersaf8446f2001-12-21 21:36:50 +0000658- Because Python's magic number scheme broke on January 1st, we decided
659 to stop Python development. Thanks for all the fish!
660
Tim Petersfb05db22002-03-11 00:24:00 +0000661- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000662 scheme to a new one. See Python/import.c for details.
663
Tim Petersaf8446f2001-12-21 21:36:50 +0000664New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000665-------------
Tim Petersaf8446f2001-12-21 21:36:50 +0000666
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000667- AtheOS is now supported.
668
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000669- the EMX runtime environment on OS/2 is now supported.
670
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000671- GNU/Hurd is now supported.
672
Tim Petersaf8446f2001-12-21 21:36:50 +0000673Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000674-----
675
676Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000677
678Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000679-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000680
Tim Peters08e72952002-04-16 20:48:01 +0000681- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
682 of that has been fixed in the installer (disabled Wise's "delete in-
683 use files" uninstall option).
684
Guido van Rossum181e41a2002-04-06 00:23:25 +0000685- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
686
Tim Peters33187922002-04-04 20:02:04 +0000687- The installer now installs Start menu shortcuts under (the local
688 equivalent of) "All Users" when doing an Admin install.
689
Tim Petersfb05db22002-03-11 00:24:00 +0000690- file.truncate([newsize]) now works on Windows for all newsize values.
691 It used to fail if newsize didn't fit in 32 bits, reflecting a
692 limitation of MS _chsize (which is no longer used).
693
Tim Petersab034fa2002-02-01 11:27:43 +0000694- os.waitpid() is now implemented for Windows, and can be used to block
695 until a specified process exits. This is similar to, but not exactly
696 the same as, os.waitpid() on POSIX systems. If you're waiting for
697 a specific process whose pid was obtained from one of the spawn()
698 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000699 See the docs for details. The docs were changed to clarify that
700 spawn functions return, and waitpid requires, a process handle on
701 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000702
Tim Peters11bd9942002-02-01 00:52:29 +0000703- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000704 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000705 to a nasty problem: before 2.3, if you got a temp file on Windows, it
706 got wrapped in an object whose close() method first closed the
707 underlying file, then deleted the file. This usually worked fine.
708 However, the spawn family of functions on Windows create (at a low C
709 level) the same set of open files in the spawned process Q as were
710 open in the spawning process P. If a temp file f was among them, then
711 doing f.close() in P first closed P's C-level file handle on f, but Q's
712 C-level file handle on f remained open, so the attempt in P to delete f
713 blew up with a "Permission denied" error (Windows doesn't allow
714 deleting open files). This was surprising, subtle, and difficult to
715 work around.
716
717- The os module now exports all the symbolic constants usable with the
718 low-level os.open() on Windows: the new constants in 2.3 are
719 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
720 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
721 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
722 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
723 (so specify both if you want both; note that neither is useful unless
724 specified with O_CREAT too).
725
Tim Petersaf8446f2001-12-21 21:36:50 +0000726Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000727----
728
729Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000730
731
Tim Peters909c0912001-12-14 23:16:18 +0000732What's New in Python 2.2 final?
Tim Peters909c0912001-12-14 23:16:18 +0000733===============================
734
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000735*Release date: 21-Dec-2001*
736
Tim Peters909c0912001-12-14 23:16:18 +0000737Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000738--------------------------------------------
Tim Peters909c0912001-12-14 23:16:18 +0000739
Barry Warsaw52acb492001-12-21 20:04:22 +0000740- pickle.py, cPickle: allow pickling instances of new-style classes
741 with a custom metaclass.
742
Tim Peters909c0912001-12-14 23:16:18 +0000743Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000744-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000745
Barry Warsaw52acb492001-12-21 20:04:22 +0000746- weakref proxy object: when comparing, unwrap both arguments if both
747 are proxies.
748
Tim Peters909c0912001-12-14 23:16:18 +0000749Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000750-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000751
Barry Warsaw52acb492001-12-21 20:04:22 +0000752- binascii.b2a_base64(): fix a potential buffer overrun when encoding
753 very short strings.
754
755- cPickle: the obscure "fast" mode was suspected of causing stack
756 overflows on the Mac. Hopefully fixed this by setting the recursion
757 limit much smaller. If the limit is too low (it only affects
758 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
759 when compiling cPickle.c (or in pyconfig.h).
760
Tim Peters909c0912001-12-14 23:16:18 +0000761Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000762-------
Tim Peters909c0912001-12-14 23:16:18 +0000763
Barry Warsaw52acb492001-12-21 20:04:22 +0000764- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
765 close or delete time).
766
767- rfc822.py: fixed a bug where the address '<>' was converted to None
768 instead of an empty string (also fixes the email.Utils module).
769
770- xmlrpclib.py: version 1.0.0; uses precision for doubles.
771
772- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000773 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000774
Tim Peters909c0912001-12-14 23:16:18 +0000775Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000776-----------
Tim Peters909c0912001-12-14 23:16:18 +0000777
778Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000779-----
Tim Peters909c0912001-12-14 23:16:18 +0000780
781C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000782-----
Tim Peters909c0912001-12-14 23:16:18 +0000783
784New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000785-------------
Tim Peters909c0912001-12-14 23:16:18 +0000786
787Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000788-----
Tim Peters909c0912001-12-14 23:16:18 +0000789
790Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000791-------
Tim Peters909c0912001-12-14 23:16:18 +0000792
Barry Warsaw52acb492001-12-21 20:04:22 +0000793- distutils package: fixed broken Windows installers (bdist_wininst).
794
795- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
796 instances are deleted at process exit time.
797
798- socket.py: prevent mysterious warnings when socket instances are
799 deleted at process exit time.
800
801- posixmodule.c: fix a Windows crash with stat() of a filename ending
802 in backslash.
803
Tim Peters909c0912001-12-14 23:16:18 +0000804Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000805----
Tim Peters909c0912001-12-14 23:16:18 +0000806
Barry Warsaw52acb492001-12-21 20:04:22 +0000807- The Carbon toolbox modules have been upgraded to Universal Headers
808 3.4, and experimental CoreGraphics and CarbonEvents modules have
809 been added. All only for framework-enabled MacOSX.
810
Tim Peters909c0912001-12-14 23:16:18 +0000811
Tim Peters6272dfd2001-12-13 19:34:00 +0000812What's New in Python 2.2c1?
Tim Petersb3c9af12001-11-17 00:21:57 +0000813===========================
814
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000815*Release date: 14-Dec-2001*
816
Tim Petersb3c9af12001-11-17 00:21:57 +0000817Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000818--------------------------------------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000819
Barry Warsaw06557452001-12-14 20:47:12 +0000820- Guido's tutorial introduction to the new type/class features has
821 been extensively updated. See
822
823 http://www.python.org/2.2/descrintro.html
824
825 That remains the primary documentation in this area.
826
Guido van Rossum33bab012001-12-05 22:45:48 +0000827- Fixed a leak: instance variables declared with __slots__ were never
828 deleted!
829
Guido van Rossum4b800852001-12-03 00:54:52 +0000830- The "delete attribute" method of descriptor objects is called
831 __delete__, not __del__. In previous releases, it was mistakenly
832 called __del__, which created an unfortunate overloading condition
833 with finalizers. (The "get attribute" and "set attribute" methods
834 are still called __get__ and __set__, respectively.)
835
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000836- Some subtle issues with the super built-in were fixed:
837
838 (a) When super itself is subclassed, its __get__ method would still
839 return an instance of the base class (i.e., of super).
840
841 (b) super(C, C()).__class__ would return C rather than super. This
842 is confusing. To fix this, I decided to change the semantics of
843 super so that it only applies to code attributes, not to data
844 attributes. After all, overriding data attributes is not
845 supported anyway.
846
847 (c) The __get__ method didn't check whether the argument was an
848 instance of the type used in creation of the super instance.
849
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000850- Previously, hash() of an instance of a subclass of a mutable type
851 (list or dictionary) would return some value, rather than raising
852 TypeError. This has been fixed. Also, directly calling
853 dict.__hash__ and list.__hash__ now raises the same TypeError
854 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000855
Guido van Rossumd331cb52001-12-05 19:46:42 +0000856- New-style objects now support deleting their __dict__. This is for
857 all intents and purposes equivalent to assigning a brand new empty
858 dictionary, but saves space if the object is not used further.
859
Tim Petersb3c9af12001-11-17 00:21:57 +0000860Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000861-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000862
Tim Peters3caca232001-12-06 06:23:26 +0000863- -Qnew now works as documented in PEP 238: when -Qnew is passed on
864 the command line, all occurrences of "/" use true division instead
865 of classic division. See the PEP for details. Note that "all"
866 means all instances in library and 3rd-party modules, as well as in
867 your own code. As the PEP says, -Qnew is intended for use only in
868 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000869 Note that test_coercion.py in the standard Python test suite fails
870 under -Qnew; this is expected, and won't be repaired until true
871 division becomes the default (in the meantime, test_coercion is
872 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000873
Fred Drake6c01e252001-12-14 17:08:12 +0000874- complex() now only allows the first argument to be a string
875 argument, and raises TypeError if either the second arg is a string
876 or if the second arg is specified when the first is a string.
877
Tim Petersb3c9af12001-11-17 00:21:57 +0000878Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000879-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000880
Martin v. Löwis560da622001-11-24 09:24:51 +0000881- gc.get_referents was renamed to gc.get_referrers.
882
Tim Petersb3c9af12001-11-17 00:21:57 +0000883Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000884-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000885
Tim Peters25059d32001-12-07 20:35:43 +0000886- Functions in the os.spawn() family now release the global interpreter
887 lock around calling the platform spawn. They should always have done
888 this, but did not before 2.2c1. Multithreaded programs calling
889 an os.spawn function with P_WAIT will no longer block all Python threads
890 until the spawned program completes. It's possible that some programs
891 relies on blocking, although more likely by accident than by design.
892
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000893- webbrowser defaults to netscape.exe on OS/2 now.
894
Martin v. Löwis652e1912001-11-25 14:50:56 +0000895- Tix.ResizeHandle exposes detach_widget, hide, and show.
896
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000897- The charset alias windows_1252 has been added.
898
Barry Warsaw06557452001-12-14 20:47:12 +0000899- types.StringTypes is a tuple containing the defined string types;
900 usually this will be (str, unicode), but if Python was compiled
901 without Unicode support it will be just (str,).
902
903- The pulldom and minidom modules were synchronized to PyXML.
904
Tim Petersb3c9af12001-11-17 00:21:57 +0000905Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000906-----------
Tim Petersb3c9af12001-11-17 00:21:57 +0000907
Barry Warsaw06557452001-12-14 20:47:12 +0000908- A new script called Tools/scripts/google.py was added, which fires
909 off a search on Google.
910
Tim Petersb3c9af12001-11-17 00:21:57 +0000911Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000912-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000913
Barry Warsaw06557452001-12-14 20:47:12 +0000914- Note that release builds of Python should arrange to define the
915 preprocessor symbol NDEBUG on the command line (or equivalent).
916 In the 2.2 pre-release series we tried to define this by magic in
917 Python.h instead, but it proved to cause problems for extension
918 authors. The Unix, Windows and Mac builds now all define NDEBUG in
919 release builds via cmdline (or equivalent) instead. Ports to
920 other platforms should do likewise.
921
Jack Jansen1999ef42001-12-06 21:47:20 +0000922- It is no longer necessary to use --with-suffix when building on a
923 case-insensitive file system (such as Mac OS X HFS+). In the build
924 directory an extension is used, but not in the installed python.
925
Tim Petersb3c9af12001-11-17 00:21:57 +0000926C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000927-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000928
Tim Petersf582b822001-12-11 18:51:08 +0000929- New function PyDict_MergeFromSeq2() exposes the builtin dict
930 constructor's logic for updating a dictionary from an iterable object
931 producing key-value pairs.
932
Tim Peterscffed4b2001-11-29 03:26:37 +0000933- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000934 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000935 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
936 dump core in some bad cases. This has been repaired. As a result,
937 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
938 previously went unchallenged.
939
Tim Petersb3c9af12001-11-17 00:21:57 +0000940New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000941-------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000942
943Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000944-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000945
946Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000947-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000948
949Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000950----
Tim Petersb3c9af12001-11-17 00:21:57 +0000951
Jack Jansenffa260f2001-12-06 21:14:00 +0000952- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
953 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000954
Barry Warsaw06557452001-12-14 20:47:12 +0000955- Changed logic for finding python home in Mac OS X framework Pythons.
956 Now sys.executable points to the executable again, in stead of to
957 the shared library. The latter is used only for locating the python
958 home.
959
960
Tim Peters84362bc2001-10-19 17:55:30 +0000961What's New in Python 2.2b2?
Tim Peters84362bc2001-10-19 17:55:30 +0000962===========================
963
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000964*Release date: 16-Nov-2001*
965
Tim Peters84362bc2001-10-19 17:55:30 +0000966Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000967--------------------------------------------
Tim Peters84362bc2001-10-19 17:55:30 +0000968
Guido van Rossum3d27df02001-11-15 20:27:54 +0000969- Multiple inheritance mixing new-style and classic classes in the
970 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000971
972 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000973 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000974
975 The MRO (method resolution order) for each base class is respected
976 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000977 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000978 This needs to be documented.
979
Tim Petersa427a2b2001-10-29 22:25:45 +0000980- The new builtin dictionary() constructor, and dictionary type, have
981 been renamed to dict. This reflects a decade of common usage.
982
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000983- dict() now accepts an iterable object producing 2-sequences. For
984 example, dict(d.items()) == d for any dictionary d. The argument,
985 and the elements of the argument, can be any iterable objects.
986
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000987- New-style classes can now have a __del__ method, which is called
988 when the instance is deleted (just like for classic classes).
989
Guido van Rossum12d955c2001-10-26 14:56:06 +0000990- Assignment to object.__dict__ is now possible, for objects that are
991 instances of new-style classes that have a __dict__ (unless the base
992 class forbids it).
993
Guido van Rossumc8e56452001-10-22 00:43:43 +0000994- Methods of built-in types now properly check for keyword arguments
995 (formerly these were silently ignored). The only built-in methods
996 that take keyword arguments are __call__, __init__ and __new__.
997
Guido van Rossum86443212001-10-27 22:28:54 +0000998- The socket function has been converted to a type; see below.
999
Tim Peters84362bc2001-10-19 17:55:30 +00001000Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001001-----------------
Tim Peters84362bc2001-10-19 17:55:30 +00001002
Jeremy Hylton249aaed2001-11-09 21:06:24 +00001003- Assignment to __debug__ raises SyntaxError at compile-time. This
1004 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +00001005 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +00001006
Guido van Rossum12d955c2001-10-26 14:56:06 +00001007- Clarified the error messages for unsupported operands to an operator
1008 (like 1 + '').
1009
Tim Peters84362bc2001-10-19 17:55:30 +00001010Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001011-----------------
Tim Peters84362bc2001-10-19 17:55:30 +00001012
Tim Peters5ebfd362001-11-13 23:11:19 +00001013- mmap has a new keyword argument, "access", allowing a uniform way for
1014 both Windows and Unix users to create read-only, write-through and
1015 copy-on-write memory mappings. This was previously possible only on
1016 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001017 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +00001018 platforms. Thanks to Jay T Miller for repairing this!
1019
Tim Peters169ded02001-11-03 19:57:21 +00001020- By default, the gc.garbage list now contains only those instances in
1021 unreachable cycles that have __del__ methods; in 2.1 it contained all
1022 instances in unreachable cycles. "Instances" here has been generalized
1023 to include instances of both new-style and old-style classes.
1024
Guido van Rossum12d955c2001-10-26 14:56:06 +00001025- The socket module defines a new method for socket objects,
1026 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +00001027 send() until all data has been sent. Also, the socket function has
1028 been converted to a subclassable type, like list and tuple (etc.)
1029 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +00001030
1031- Various bugfixes to the curses module. There is now a test suite
1032 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001033
Guido van Rossum692adf12001-10-30 03:03:03 +00001034- binascii.b2a_base64 no longer places an arbitrary restriction of 57
1035 bytes on its input.
1036
Tim Peters84362bc2001-10-19 17:55:30 +00001037Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001038-------
Tim Peters84362bc2001-10-19 17:55:30 +00001039
Tim Peters5ebfd362001-11-13 23:11:19 +00001040- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +00001041 convenience function.
1042
Tim Peters75335872001-11-03 19:35:43 +00001043- Symbolic group names in regular expressions must be unique. For
1044 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
1045 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +00001046 Python 2.2 detects this error at regexp compilation time;
1047 previously, the error went undetected, and results were
1048 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
1049 pattern.subn() methods have been rewritten in C. Also, an
1050 experimental function/method finditer() has been added, which works
1051 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +00001052
Martin v. Löwisb7b32602001-11-02 23:48:20 +00001053- Tix exposes more commands through the classes DirSelectBox,
1054 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
1055 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
1056 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
1057
Tim Peters98791af2001-10-23 01:59:54 +00001058- Traceback objects are now scanned by cyclic garbage collection, so
1059 cycles created by casual use of sys.exc_info() no longer cause
1060 permanent memory leaks (provided garbage collection is enabled).
1061
Guido van Rossum49192142001-10-24 20:51:44 +00001062- os.extsep -- a new variable needed by the RISCOS support. It is the
1063 separator used by extensions, and is '.' on all platforms except
1064 RISCOS, where it is '/'. There is no need to use this variable
1065 unless you have a masochistic desire to port your code to RISCOS.
1066
Barry Warsaw012852b2001-11-16 16:17:27 +00001067- mimetypes.py has optional support for non-standard, but commonly
1068 found types. guess_type() and guess_extension() now accept an
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001069 optional 'strict' flag, defaulting to true, which controls whether
Barry Warsaw012852b2001-11-16 16:17:27 +00001070 recognize non-standard types or not. A few non-standard types we
1071 know about have been added. Also, when run as a script, there are
1072 new -l and -e options.
1073
1074- statcache is now deprecated.
1075
1076- email.Utils.formatdate() now produces the preferred RFC 2822 style
1077 dates with numeric timezones (it used to produce obsolete dates
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001078 hard coded to "GMT" timezone). An optional 'localtime' flag is
Barry Warsaw012852b2001-11-16 16:17:27 +00001079 added to produce dates in the local timezone, with daylight savings
1080 time properly taken into account.
1081
1082- In pickle and cPickle, instead of masking errors in load() by
1083 transforming them into SystemError, we let the original exception
1084 propagate out. Also, implement support for __safe_for_unpickling__
1085 in pickle, as it already was supported in cPickle.
1086
Tim Peters84362bc2001-10-19 17:55:30 +00001087Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001088-----------
Tim Peters84362bc2001-10-19 17:55:30 +00001089
1090Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001091-----
Tim Peters84362bc2001-10-19 17:55:30 +00001092
Barry Warsaw012852b2001-11-16 16:17:27 +00001093- The dbm module is built using libdb1 if available. The bsddb module
1094 is built with libdb3 if available.
1095
1096- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
1097
Tim Peters84362bc2001-10-19 17:55:30 +00001098C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001099-----
Tim Peters84362bc2001-10-19 17:55:30 +00001100
Tim Peters1fc240e2001-10-26 05:06:50 +00001101- New function PySequence_Fast_GET_SIZE() returns the size of a non-
1102 NULL result from PySequence_Fast(), more quickly than calling
1103 PySequence_Size().
1104
Barry Warsaw012852b2001-11-16 16:17:27 +00001105- New argument unpacking function PyArg_UnpackTuple() added.
1106
1107- New functions PyObject_CallFunctionObjArgs() and
1108 PyObject_CallMethodObjArgs() have been added to make it more
1109 convenient and efficient to call functions and methods from C.
1110
1111- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
1112 possible that this will propagate errors it didn't before.
1113
1114- New function PyObject_CheckReadBuffer(), which returns true if its
1115 argument supports the single-segment readable buffer interface.
1116
Tim Peters84362bc2001-10-19 17:55:30 +00001117New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001118-------------
Tim Peters84362bc2001-10-19 17:55:30 +00001119
Guido van Rossum86443212001-10-27 22:28:54 +00001120- We've finally confirmed that this release builds on HP-UX 11.00,
1121 *with* threads, and passes the test suite.
1122
Tim Peters7a33d8b2001-11-05 02:51:07 +00001123- Thanks to a series of patches from Michael Muller, Python may build
1124 again under OS/2 Visual Age C++.
1125
Guido van Rossum49192142001-10-24 20:51:44 +00001126- Updated RISCOS port by Dietmar Schwertberger.
1127
Tim Peters84362bc2001-10-19 17:55:30 +00001128Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001129-----
Tim Peters84362bc2001-10-19 17:55:30 +00001130
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001131- Added a test script for the curses module. It isn't run automatically;
1132 regrtest.py must be run with '-u curses' to enable it.
1133
Tim Peters84362bc2001-10-19 17:55:30 +00001134Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001135-------
Tim Peters84362bc2001-10-19 17:55:30 +00001136
Barry Warsaw012852b2001-11-16 16:17:27 +00001137Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001138----
Barry Warsaw012852b2001-11-16 16:17:27 +00001139
1140- PythonScript has been moved to unsupported and is slated to be
1141 removed completely in the next release.
1142
1143- It should now be possible to build applets that work on both OS9 and
1144 OSX.
1145
1146- The core is now linked with CoreServices not Carbon; as a side
1147 result, default 8bit encoding on OSX is now ASCII.
1148
1149- Python should now build on OSX 10.1.1
1150
Tim Peters84362bc2001-10-19 17:55:30 +00001151
Tim Petersabf925f2001-09-28 21:53:42 +00001152What's New in Python 2.2b1?
Tim Petersabf925f2001-09-28 21:53:42 +00001153===========================
1154
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001155*Release date: 19-Oct-2001*
1156
Tim Petersabf925f2001-09-28 21:53:42 +00001157Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001158--------------------------------------------
Tim Petersabf925f2001-09-28 21:53:42 +00001159
Guido van Rossum687ae002001-10-15 22:03:32 +00001160- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001161 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +00001162 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001163 remains: the __dict__ of a new-style class is a read-only proxy; you
1164 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +00001165 __defined__ attribute of new-style types no longer exists, for lack
1166 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001167 future a __cache__ may be resurrected with a similar function, if I
1168 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +00001169
Tim Peters1c9ca872001-10-04 06:43:12 +00001170- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
1171 always returned None, even when there was a class docstring).
1172
1173- doctest now finds and runs docstrings attached to new-style classes,
1174 class methods, static methods, and properties.
1175
Guido van Rossum9074ef62001-10-16 21:34:49 +00001176Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001177-----------------
Tim Petersabf925f2001-09-28 21:53:42 +00001178
Guido van Rossuma8bcf802001-10-15 15:53:58 +00001179- A very subtle syntactical pitfall in list comprehensions was fixed.
1180 For example: [a+b for a in 'abc', for b in 'def']. The comma in
1181 this example is a mistake. Previously, this would silently let 'a'
1182 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
1183 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
1184 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
1185 Note that [a for a in <singleton>] is a convoluted way to say
1186 [<singleton>] anyway, so it's not like any expressiveness is lost.
1187
Guido van Rossum9074ef62001-10-16 21:34:49 +00001188- getattr(obj, name, default) now only catches AttributeError, as
1189 documented, rather than returning the default value for all
1190 exceptions (which could mask bugs in a __getattr__ hook, for
1191 example).
1192
Fred Drakecb7a6b52001-10-22 18:41:51 +00001193- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +00001194 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001195 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +00001196 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +00001197
Guido van Rossum1c486092001-10-19 02:05:35 +00001198- unicode(obj) now behaves more like str(obj), accepting arbitrary
1199 objects, and calling a __unicode__ method if it exists.
1200 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +00001201 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +00001202
Barry Warsawf6fb1712001-10-19 05:35:40 +00001203- isinstance() now allows any object as the first argument and a
1204 class, a type or something with a __bases__ tuple attribute for the
1205 second argument. The second argument may also be a tuple of a
1206 class, type, or something with __bases__, in which case isinstance()
1207 will return true if the first argument is an instance of any of the
1208 things contained in the second argument tuple. E.g.
1209
1210 isinstance(x, (A, B))
1211
1212 returns true if x is an instance of A or B.
1213
Guido van Rossum9074ef62001-10-16 21:34:49 +00001214Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001215-----------------
Guido van Rossum9074ef62001-10-16 21:34:49 +00001216
1217- thread.start_new_thread() now returns the thread ID (previously None).
1218
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001219- binascii has now two quopri support functions, a2b_qp and b2a_qp.
1220
Guido van Rossumc524d952001-10-19 01:31:59 +00001221- readline now supports setting the startup_hook and the
1222 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +00001223
Guido van Rossumc524d952001-10-19 01:31:59 +00001224- os and posix supports chroot(), setgroups() and unsetenv() where
1225 available. The stat(), fstat(), statvfs() and fstatvfs() functions
1226 now return "pseudo-sequences" -- the various fields can now be
1227 accessed as attributes (e.g. os.stat("/").st_mtime) but for
1228 backwards compatibility they also behave as a fixed-length sequence.
1229 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +00001230 attributes.
1231
1232- time: localtime(), gmtime() and strptime() now return a
1233 pseudo-sequence similar to the os.stat() return value, with
1234 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +00001235
Guido van Rossum9074ef62001-10-16 21:34:49 +00001236- Decompression objects in the zlib module now accept an optional
1237 second parameter to decompress() that specifies the maximum amount
1238 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +00001239
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001240- optional SSL support in the socket module now exports OpenSSL
1241 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
1242 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +00001243 automatically seed its PRNG. Also, the keyfile and certfile
1244 arguments to socket.ssl() are now optional.
1245
1246- posixmodule (and by extension, the os module on POSIX platforms) now
1247 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001248
Guido van Rossum9074ef62001-10-16 21:34:49 +00001249Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001250-------
Guido van Rossum3c288632001-10-16 21:13:49 +00001251
Tim Peters7402f792001-10-02 03:53:41 +00001252- doctest now excludes functions and classes not defined by the module
1253 being tested, thanks to Tim Hochberg.
1254
Fred Drakecb7a6b52001-10-22 18:41:51 +00001255- HotShot, a new profiler implemented using a C-based callback, has
1256 been added. This substantially reduces the overhead of profiling,
1257 but it is still quite preliminary. Support modules and
1258 documentation will be added in upcoming releases (before 2.2 final).
1259
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001260- profile now produces correct output in situations where an exception
1261 raised in Python is cleared by C code (e.g. hasattr()). This used
1262 to cause wrong output, including spurious claims of recursive
1263 functions and attribution of time spent to the wrong function.
1264
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001265 The code and documentation for the derived OldProfile and HotProfile
1266 profiling classes was removed. The code hasn't worked for years (if
1267 you tried to use them, they raised exceptions). OldProfile
1268 intended to reproduce the behavior of the profiler Python used more
1269 than 7 years ago, and isn't interesting anymore. HotProfile intended
1270 to provide a faster profiler (but producing less information), and
1271 that's a worthy goal we intend to meet via a different approach (but
1272 without losing information).
1273
Tim Peterscce092d2001-10-09 05:31:56 +00001274- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001275 a much better system-specific calibration constant. The constant can
1276 now be specified in an instance constructor, or as a Profile class or
1277 instance variable, instead of by editing profile.py's source code.
1278 Calibration must still be done manually (see the docs for the profile
1279 module).
1280
1281 Note that Profile.calibrate() must be overriden by subclasses.
1282 Improving the accuracy required exploiting detailed knowledge of
1283 profiler internals; the earlier method abstracted away the details
1284 and measured a simplified model instead, but consequently computed
1285 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001286
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001287- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001288 which indicates whether output is intended for the header 'Q'
1289 encoding.
1290
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001291- The SocketServer.ThreadingMixIn class now closes the request after
1292 finish_request() returns. (Not when it errors out though.)
1293
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001294- The nntplib module's NNTP.body() method has grown a 'file' argument
Barry Warsawf6fb1712001-10-19 05:35:40 +00001295 to allow saving the message body to a file.
1296
1297- The email package has added a class email.Parser.HeaderParser which
1298 only parses headers and does not recurse into the message's body.
1299 Also, the module/class MIMEAudio has been added for representing
1300 audio data (contributed by Anthony Baxter).
1301
1302- ftplib should be able to handle files > 2GB.
1303
1304- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1305 ON, and OFF.
1306
Fred Drakecb7a6b52001-10-22 18:41:51 +00001307- xml.dom.minidom NodeList objects now support the length attribute
1308 and item() method as required by the DOM specifications.
1309
Guido van Rossumed554f62001-10-02 23:15:37 +00001310Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001311-----------
Guido van Rossumed554f62001-10-02 23:15:37 +00001312
1313- Demo/dns was removed. It no longer serves any purpose; a package
1314 derived from it is now maintained by Anthony Baxter, see
1315 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001316
Barry Warsawf6fb1712001-10-19 05:35:40 +00001317- The freeze tool has been made more robust, and two new options have
1318 been added: -X and -E.
1319
Tim Petersabf925f2001-09-28 21:53:42 +00001320Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001321-----
Tim Petersabf925f2001-09-28 21:53:42 +00001322
Barry Warsawf6fb1712001-10-19 05:35:40 +00001323- configure will use CXX in LINKCC if CXX is used to build main() and
1324 the system requires to link a C++ main using the C++ compiler.
1325
Tim Petersabf925f2001-09-28 21:53:42 +00001326C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001327-----
Tim Petersabf925f2001-09-28 21:53:42 +00001328
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001329- The documentation for the tp_compare slot is updated to require that
1330 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1331 not correct. This is not yet enforced but will be enforced in
1332 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1333 "NotImplemented". Right now, -1 should be used for an error return.
1334
Tim Petersd38b1c72001-09-30 05:09:37 +00001335- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1336 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1337 as long) arguments.
1338
Guido van Rossum3c288632001-10-16 21:13:49 +00001339- PyThread_start_new_thread() now returns a long int giving the thread
1340 ID, if one can be calculated; it returns -1 for error, 0 if no
1341 thread ID is calculated (this is an incompatible change, but only
1342 the thread module used this API). This code has only really been
1343 tested on Linux and Windows; other platforms please beware (and
1344 report any bugs or strange behavior).
1345
Guido van Rossum1c486092001-10-19 02:05:35 +00001346- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1347 input.
1348
Tim Petersabf925f2001-09-28 21:53:42 +00001349New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001350-------------
Tim Petersabf925f2001-09-28 21:53:42 +00001351
1352Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001353-----
Tim Petersabf925f2001-09-28 21:53:42 +00001354
1355Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001356-------
Tim Petersabf925f2001-09-28 21:53:42 +00001357
Tim Peters04cf1d32001-10-09 22:39:40 +00001358- Installer: If you install IDLE, and don't disable file-extension
1359 registration, a new "Edit with IDLE" context (right-click) menu entry
1360 is created for .py and .pyw files.
1361
Tim Peters1ce3cf72001-10-01 17:58:40 +00001362- The signal module now supports SIGBREAK on Windows, thanks to Steven
1363 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1364 action remains to call Win32 ExitProcess(). This can be changed via
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001365 signal.signal(). For example::
Tim Peters1ce3cf72001-10-01 17:58:40 +00001366
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001367 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1368 # (SIGINT) behavior.
1369 import signal
1370 signal.signal(signal.SIGBREAK, signal.default_int_handler)
Tim Peters1ce3cf72001-10-01 17:58:40 +00001371
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001372 try:
1373 while 1:
1374 pass
1375 except KeyboardInterrupt:
1376 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1377 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1378 # program without the possibility for any Python-level cleanup).
1379 print "Clean exit"
Tim Peters1ce3cf72001-10-01 17:58:40 +00001380
Tim Petersabf925f2001-09-28 21:53:42 +00001381
Tim Petersb07352e2001-09-08 01:25:47 +00001382What's New in Python 2.2a4?
1383===========================
1384
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001385*Release date: 28-Sep-2001*
1386
Guido van Rossum808eea72001-09-25 04:15:41 +00001387Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001388--------------------------------------------
Guido van Rossum808eea72001-09-25 04:15:41 +00001389
1390- pydoc and inspect are now aware of new-style classes;
1391 e.g. help(list) at the interactive prompt now shows proper
1392 documentation for all operations on list objects.
1393
1394- Applications using Jim Fulton's ExtensionClass module can now safely
1395 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1396 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1397 examples also work again. It is hoped that Gtk and Boost also work
1398 with 2.2a4 and beyond. (If you can confirm this, please write
1399 webmaster@python.org; if there are still problems, please open a bug
1400 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001401
Tim Peters66c1a522001-09-24 21:17:50 +00001402- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001403 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001404 in the constructed property object. fget, fset and fdel weren't
1405 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1406 associate a docstring with a property.
1407
Guido van Rossum808eea72001-09-25 04:15:41 +00001408- Comparison overloading is now more completely implemented. For
1409 example, a str subclass instance can properly be compared to a str
1410 instance, and it can properly overload comparison. Ditto for most
1411 other built-in object types.
1412
1413- The repr() of new-style classes has changed; instead of <type
1414 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1415 *except* for built-in types, which are still rendered as <type
1416 'Foo'> (to avoid upsetting existing code that might parse or
1417 otherwise rely on repr() of certain type objects).
1418
1419- The repr() of new-style objects is now always <Foo object at XXX>;
1420 previously, it was sometimes <Foo instance at XXX>.
1421
1422- For new-style classes, what was previously called __getattr__ is now
1423 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001424 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001425 one in classic classes is defined which is called only if regular
1426 attribute access raises AttributeError; to catch *all* attribute
1427 access, you can use __getattribute__ (for new-style classes). If
1428 both are defined, __getattribute__ is called first, and if it raises
1429 AttributeError, __getattr__ is called.
1430
1431- The __class__ attribute of new-style objects can be assigned to.
1432 The new class must have the same C-level object layout as the old
1433 class.
1434
1435- The builtin file type can be subclassed now. In the usual pattern,
1436 "file" is the name of the builtin type, and file() is a new builtin
1437 constructor, with the same signature as the builtin open() function.
1438 file() is now the preferred way to open a file.
1439
1440- Previously, __new__ would only see sequential arguments passed to
1441 the type in a constructor call; __init__ would see both sequential
1442 and keyword arguments. This made no sense whatsoever any more, so
1443 now both __new__ and __init__ see all arguments.
1444
1445- Previously, hash() applied to an instance of a subclass of str or
1446 unicode always returned 0. This has been repaired.
1447
1448- Previously, an operation on an instance of a subclass of an
1449 immutable type (int, long, float, complex, tuple, str, unicode),
1450 where the subtype didn't override the operation (and so the
1451 operation was handled by the builtin type), could return that
1452 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001453 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001454 with the same value as s.
1455
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001456- Provisional support for pickling new-style objects has been added.
1457
Guido van Rossum808eea72001-09-25 04:15:41 +00001458Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001459----
Guido van Rossum808eea72001-09-25 04:15:41 +00001460
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001461- file.writelines() now accepts any iterable object producing strings.
1462
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001463- PyUnicode_FromEncodedObject() now works very much like
1464 PyObject_Str(obj) in that it tries to use __str__/tp_str
1465 on the object if the object is not a string or buffer. This
1466 makes unicode() behave like str() when applied to non-string/buffer
1467 objects.
1468
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001469- PyFile_WriteObject now passes Unicode objects to the file's write
1470 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001471 of a print statement must support Unicode objects, i.e. they must
1472 at least convert them into ASCII strings.
1473
Guido van Rossum624c8af2001-09-18 15:21:04 +00001474- Thread scheduling on Solaris should be improved; it is no longer
1475 necessary to insert a small sleep at the start of a thread in order
1476 to let other runnable threads be scheduled.
1477
Tim Petersb07352e2001-09-08 01:25:47 +00001478Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001479-------
Tim Petersb07352e2001-09-08 01:25:47 +00001480
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001481- StringIO.StringIO instances and cStringIO.StringIO instances support
1482 read character buffer compatible objects for their .write() methods.
1483 These objects are converted to strings and then handled as such
1484 by the instances.
1485
Barry Warsaw2f600732001-09-24 04:28:10 +00001486- The "email" package has been added. This is basically a port of the
1487 mimelib package <http://sf.net/projects/mimelib> with API changes
1488 and some implementations updated to use iterators and generators.
1489
Tim Peters8a9c2842001-09-22 21:30:22 +00001490- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1491 restores the ability of Tools/scripts/ndiff.py to start producing output
1492 before the entire comparison is complete.
1493
Barry Warsaw58b072d2001-09-22 04:44:21 +00001494- StringIO.StringIO instances and cStringIO.StringIO instances support
1495 iteration just like file objects (i.e. their .readline() method is
1496 called for each iteration until it returns an empty string).
1497
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001498- The codecs module has grown four new helper APIs to access
1499 builtin codecs: getencoder(), getdecoder(), getreader(),
1500 getwriter().
1501
Guido van Rossum624c8af2001-09-18 15:21:04 +00001502- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1503 simplifies writing XML RPC servers.
1504
Barry Warsaw647d5e82001-09-28 17:01:02 +00001505- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001506 after interpretation of symbolic links. On non-Unix systems, this
1507 is an alias for os.path.abspath().
1508
Tim Peters16a77ad2001-09-08 04:00:12 +00001509- operator.indexOf() (PySequence_Index() in the C API) now works with any
1510 iterable object.
1511
Guido van Rossum624c8af2001-09-18 15:21:04 +00001512- smtplib now supports various authentication and security features of
1513 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001514
Guido van Rossum624c8af2001-09-18 15:21:04 +00001515- hmac: a new module implementing keyed hashing for message
1516 authentication.
1517
1518- mimetypes now recognizes more extensions and file types. At the
1519 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001520
Guido van Rossum624c8af2001-09-18 15:21:04 +00001521- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001522 Python 2.2 bytecode generation. It has also been promoted from a
1523 Tool to a standard library package. (Tools/compiler still exists as
1524 a sample driver.)
1525
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001526Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001527-----
Guido van Rossum624c8af2001-09-18 15:21:04 +00001528
Tim Petersb07352e2001-09-08 01:25:47 +00001529Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001530-----
Tim Petersb07352e2001-09-08 01:25:47 +00001531
Guido van Rossum624c8af2001-09-18 15:21:04 +00001532- Large file support (LFS) is now automatic when the platform supports
1533 it; no more manual configuration tweaks are needed. On Linux, at
1534 least, it's possible to have a system whose C library supports large
1535 files but whose kernel doesn't; in this case, large file support is
1536 still enabled but doesn't do you any good unless you upgrade your
1537 kernel or share your Python executable with another system whose
1538 kernel has large file support.
1539
1540- The configure script now supplies plausible defaults in a
1541 cross-compilation environment. This doesn't mean that the supplied
1542 values are always correct, or that cross-compilation now works
1543 flawlessly -- but it's a first step (and it shuts up most of
1544 autoconf's warnings about AC_TRY_RUN).
1545
1546- The Unix build is now a bit less chatty, courtesy of the parser
1547 generator. The build is completely silent (except for errors) when
1548 using "make -s", thanks to a -q option to setup.py.
1549
Tim Petersb07352e2001-09-08 01:25:47 +00001550C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001551-----
Tim Petersb07352e2001-09-08 01:25:47 +00001552
Guido van Rossum624c8af2001-09-18 15:21:04 +00001553- The "structmember" API now supports some new flag bits to deny read
1554 and/or write access to attributes in restricted execution mode.
1555
Tim Petersb07352e2001-09-08 01:25:47 +00001556New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001557-------------
Tim Petersb07352e2001-09-08 01:25:47 +00001558
Guido van Rossum624c8af2001-09-18 15:21:04 +00001559- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1560 (http://familiar.handhelds.org).
1561
Tim Petersb07352e2001-09-08 01:25:47 +00001562Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001563-----
Tim Petersb07352e2001-09-08 01:25:47 +00001564
Tim Peters8a9c2842001-09-22 21:30:22 +00001565- The "classic" standard tests, which work by comparing stdout to
1566 an expected-output file under Lib/test/output/, no longer stop at
1567 the first mismatch. Instead the test is run to completion, and a
1568 variant of ndiff-style comparison is used to report all differences.
1569 This is much easier to understand than the previous style of reporting.
1570
1571- The unittest-based standard tests now use regrtest's test_main()
1572 convention, instead of running as a side-effect of merely being
1573 imported. This allows these tests to be run in more natural and
1574 flexible ways as unittests, outside the regrtest framework.
1575
1576- regrtest.py is much better integrated with unittest and doctest now,
1577 especially in regard to reporting errors.
1578
Tim Petersb07352e2001-09-08 01:25:47 +00001579Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001580-------
Tim Petersb07352e2001-09-08 01:25:47 +00001581
Guido van Rossum624c8af2001-09-18 15:21:04 +00001582- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001583 that support it (NTFS under Windows 2000). See "What's New in
1584 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001585
Tim Petersb07352e2001-09-08 01:25:47 +00001586
Tim Petersedc99312001-08-22 21:36:50 +00001587What's New in Python 2.2a3?
1588===========================
1589
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001590*Release Date: 07-Sep-2001*
1591
Tim Petersedc99312001-08-22 21:36:50 +00001592Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001593----
Tim Petersedc99312001-08-22 21:36:50 +00001594
Tim Peters9fffa3e2001-09-04 05:14:19 +00001595- Conversion of long to float now raises OverflowError if the long is too
1596 big to represent as a C double.
1597
Tim Peters32f453e2001-09-03 08:35:41 +00001598- The 3-argument builtin pow() no longer allows a third non-None argument
1599 if either of the first two arguments is a float, or if both are of
1600 integer types and the second argument is negative (in which latter case
1601 the arguments are converted to float, so this is really the same
1602 restriction).
1603
Tim Peters5d2b77c2001-09-03 05:47:38 +00001604- The builtin dir() now returns more information, and sometimes much
1605 more, generally naming all attributes of an object, and all attributes
1606 reachable from the object via its class, and from its class's base
1607 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1608 an empty list. In 2.2a3,
1609
1610 >>> dir([])
1611 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1612 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1613 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1614 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1615 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1616 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1617 'reverse', 'sort']
1618
1619 dir(module) continues to return only the module's attributes, though.
1620
Tim Petersbdee63f2001-09-02 03:40:59 +00001621- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001622 than raising OverflowError. This is a partial implementation of PEP
1623 237. You can use -Wdefault::OverflowWarning to enable a warning for
1624 this situation, and -Werror::OverflowWarning to revert to the old
1625 OverflowError exception.
1626
Guido van Rossum61c345f2001-09-04 03:26:15 +00001627- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001628 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001629 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1630 -Qold, meaning the / operator has its classic meaning and no
1631 warnings are issued. Using -Qwarn issues a run-time warning about
1632 all uses of classic division for int and long arguments; -Qwarnall
1633 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001634 (for use with fixdiv.py).
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001635 [Note: the remainder of this item (preserved below) became
1636 obsolete in 2.2c1 -- -Qnew has global effect in 2.2] ::
1637
1638 Using -Qnew is questionable; it turns on new division by default, but
1639 only in the __main__ module. You can usefully combine -Qwarn or
1640 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1641 warns about classic division everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +00001642
Tim Petersbdee63f2001-09-02 03:40:59 +00001643- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001644 long, float, str, unicode, and tuple. (The types complex, list and
1645 dictionary can also be subclassed; this was introduced earlier.)
1646 Note that restrictions apply when subclassing immutable built-in
1647 types: you can only affect the value of the instance by overloading
1648 __new__. You can add mutable attributes, and the subclass instances
1649 will have a __dict__ attribute, but you cannot change the "value"
1650 (as implemented by the base class) of an immutable subclass instance
1651 once it is created.
1652
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001653- The dictionary constructor now takes an optional argument, a
1654 mapping-like object, and initializes the dictionary from its
1655 (key, value) pairs.
1656
Tim Petersbdee63f2001-09-02 03:40:59 +00001657- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001658 "cooperative super calls" in a multiple inheritance setting. For an
1659 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1660
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001661- A new built-in type, property, has been added. This enables the
1662 creation of "properties". These are attributes implemented by
1663 getter and setter functions (or only one of these for read-only or
1664 write-only attributes), without the need to override __getattr__.
1665 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001666
Tim Petersbdee63f2001-09-02 03:40:59 +00001667- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001668 liberalized, to allow leading zeroes. Examples of literals now
1669 legal that were SyntaxErrors before:
1670
1671 00.0 0e3 0100j 07.5 00000000000000000008.
1672
Tim Petersbdee63f2001-09-02 03:40:59 +00001673- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001674 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1675
Tim Petersedc99312001-08-22 21:36:50 +00001676Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001677-------
Tim Petersedc99312001-08-22 21:36:50 +00001678
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001679- telnetlib includes symbolic names for the options, and support for
1680 setting an option negotiation callback.
1681
Tim Petersa40c7932001-09-05 22:36:56 +00001682- The new C standard no longer requires that math libraries set errno to
1683 ERANGE on overflow. For platform libraries that exploit this new
1684 freedom, Python's overflow-checking was wholly broken. A new overflow-
1685 checking scheme attempts to repair that, but may not be reliable on all
1686 platforms (C doesn't seem to provide anything both useful and portable
1687 in this area anymore).
1688
Martin v. Löwis44f86962001-09-05 13:44:54 +00001689- Asynchronous timeout actions are available through the new class
1690 threading.Timer.
1691
Tim Peters78526162001-09-05 00:53:45 +00001692- math.log and math.log10 now return sensible results for even huge
1693 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1694
Tim Petersbdee63f2001-09-02 03:40:59 +00001695- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001696 currently held. See the docs for the imp module.
1697
Tim Petersbdee63f2001-09-02 03:40:59 +00001698- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001699 dumps containing ints written on platforms where Python ints are 8 bytes.
1700 When read on a box where Python ints are 4 bytes, such values are
1701 converted to Python longs.
1702
Tim Petersbdee63f2001-09-02 03:40:59 +00001703- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001704 code objects is no longer allowed. This plugs a security hole.
1705
Steve Purcell6091cd62001-09-06 16:05:17 +00001706- unittest.TestResult instances no longer store references to tracebacks
1707 generated by test failures. This prevents unexpected dangling references
1708 to objects that should be garbage collected between tests.
1709
Tim Petersedc99312001-08-22 21:36:50 +00001710Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001711-----
Tim Petersedc99312001-08-22 21:36:50 +00001712
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001713- Tools/scripts/fixdiv.py has been added which can be used to fix
1714 division operators as per PEP 238.
1715
Tim Petersedc99312001-08-22 21:36:50 +00001716Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001717-----
Tim Petersedc99312001-08-22 21:36:50 +00001718
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001719- If you are an adventurous person using Mac OS X you may want to look at
1720 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1721 application, which can be used for experimenting with Carbon or Cocoa.
1722 Discussion of this on pythonmac-sig, please.
1723
Tim Peters7eea37e2001-09-04 22:08:56 +00001724C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001725-----
Tim Peters7eea37e2001-09-04 22:08:56 +00001726
1727- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001728
Tim Peters9fffa3e2001-09-04 05:14:19 +00001729- Note that PyLong_AsDouble can fail! This has always been true, but no
1730 callers checked for it. It's more likely to fail now, because overflow
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001731 errors are properly detected now. The proper way to check::
Tim Peters9fffa3e2001-09-04 05:14:19 +00001732
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001733 double x = PyLong_AsDouble(some_long_object);
1734 if (x == -1.0 && PyErr_Occurred()) {
1735 /* The conversion failed. */
1736 }
Tim Peters9fffa3e2001-09-04 05:14:19 +00001737
Tim Petersbdee63f2001-09-02 03:40:59 +00001738- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001739 compile but will not participate in GC. To upgrade an extension
1740 module:
1741
1742 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001743
Neil Schemenauer4042c692001-08-30 15:38:01 +00001744 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1745 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001746
Neil Schemenauer4042c692001-08-30 15:38:01 +00001747 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1748 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001749
Neil Schemenauer4042c692001-08-30 15:38:01 +00001750 - remove PyGC_HEAD_SIZE from object size calculations
1751
1752 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1753
Tim Petersbdee63f2001-09-02 03:40:59 +00001754- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001755 These can be used safely to construct string objects from a
1756 sprintf-style format string (similar to the format string supported
1757 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001758
Tim Petersedc99312001-08-22 21:36:50 +00001759New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001760-------------
Tim Petersedc99312001-08-22 21:36:50 +00001761
Tim Petersb7da0902001-09-02 23:01:43 +00001762- Stephen Hansen contributed patches sufficient to get a clean compile
1763 under Borland C (Windows), but he reports problems running it and ran
1764 out of time to complete the port. Volunteers? Expect a MemoryError
1765 when importing the types module; this is probably shallow, and
1766 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001767
Tim Petersedc99312001-08-22 21:36:50 +00001768Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001769-----
Tim Petersedc99312001-08-22 21:36:50 +00001770
1771Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001772-------
Tim Petersedc99312001-08-22 21:36:50 +00001773
Tim Peters6e13a562001-09-06 00:32:15 +00001774- Large file support is now enabled on Win32 platforms as well as on
1775 Win64. This means that, for example, you can use f.tell() and f.seek()
1776 to manipulate files larger than 2 gigabytes (provided you have enough
1777 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001778 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1779 filesize limit, and large file support makes no difference there.
1780 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1781 NTFS has no practical limit on file size, and files of any size can be
1782 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001783
Tim Petersbdee63f2001-09-02 03:40:59 +00001784- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001785 points to command.com (patch from Brian Quinlan).
1786
Tim Petersedc99312001-08-22 21:36:50 +00001787
Tim Peters20f51a72001-07-21 02:31:40 +00001788What's New in Python 2.2a2?
1789===========================
1790
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001791*Release Date: 22-Aug-2001*
1792
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001793Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001794-----
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001795
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001796- Tim Peters developed a brand new Windows installer using Wise 8.1,
1797 generously donated to us by Wise Solutions.
1798
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001799- configure supports a new option --enable-unicode, with the values
1800 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1801 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001802
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001803- A new configure option --enable-framework builds a Mac OS X framework,
1804 which "make frameworkinstall" will install. This provides a starting
1805 point for more mac-like functionality, join pythonmac-sig@python.org
1806 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001807
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001808- The NeXT platform is no longer supported.
1809
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001810- The 'new' module is now statically linked.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001811
Tim Peters0afb6092001-08-15 06:06:44 +00001812Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001813-----
Tim Peters0afb6092001-08-15 06:06:44 +00001814
1815- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001816 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001817 the module docstring for details.
1818
Tim Peters20f51a72001-07-21 02:31:40 +00001819Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001820-----
Tim Peters20f51a72001-07-21 02:31:40 +00001821
Tim Peters5e824c32001-08-12 22:25:01 +00001822- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001823 platforms, allowing to give clearer test result output. regrtest
1824 also has optional --use/-u switch to run normally disabled tests
1825 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001826
Tim Peters20f51a72001-07-21 02:31:40 +00001827- Several new tests in the standard test suite, with special thanks to
1828 Nick Mathewson.
1829
1830Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001831----
Tim Peters20f51a72001-07-21 02:31:40 +00001832
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001833- The floor division operator // has been added as outlined in PEP
1834 238. The / operator still provides classic division (and will until
1835 Python 3.0) unless "from __future__ import division" is included, in
1836 which case the / operator will provide true division. The operator
1837 module provides truediv() and floordiv() functions. Augmented
1838 assignment variants are included, as are the equivalent overloadable
1839 methods and C API methods. See the PEP for a full discussion:
1840 <http://python.sf.net/peps/pep-0238.html>
1841
Tim Peters6cd6a822001-08-17 22:11:27 +00001842- Future statements are now effective in simulated interactive shells
1843 (like IDLE). This should "just work" by magic, but read Michael
1844 Hudson's "Future statements in simulated shells" PEP 264 for full
1845 details: <http://python.sf.net/peps/pep-0264.html>.
1846
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001847- The type/class unification (PEP 252-253) was integrated into the
1848 trunk and is not so tentative any more (the exact specification of
1849 some features is still tentative). A lot of work has done on fixing
1850 bugs and adding robustness and features (performance still has to
1851 come a long way).
1852
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001853- Warnings about a mismatch in the Python API during extension import
1854 now use the Python warning framework (which makes it possible to
1855 write filters for these warnings).
1856
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001857- A function's __dict__ (aka func_dict) will now always be a
1858 dictionary. It used to be possible to delete it or set it to None,
1859 but now both actions raise TypeErrors. It is still legal to set it
1860 to a dictionary object. Getting func.__dict__ before any attributes
1861 have been assigned now returns an empty dictionary instead of None.
1862
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001863- A new command line option, -E, was added which disables the use of
1864 all environment variables, or at least those that are specifically
1865 significant to Python. Usually those have a name starting with
1866 "PYTHON". This was used to fix a problem where the tests fail if
1867 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1868 older distribution.
1869
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001870Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001871-------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001872
Tim Peters5e824c32001-08-12 22:25:01 +00001873- New class Differ and new functions ndiff() and restore() in difflib.py.
1874 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001875 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001876
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001877- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1878 value using the minimal quoting required for the value; more
1879 reliable than using xml.sax.saxutils.escape() for attribute values.
1880
1881- Readline completion support for cmd.Cmd was added.
1882
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001883- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1884
1885- Added function threading.BoundedSemaphore()
1886
1887- Added Ka-Ping Yee's cgitb.py module.
1888
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001889- The 'new' module now exposes the CO_xxx flags.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001890
Martin v. Löwis560da622001-11-24 09:24:51 +00001891- The gc module offers the get_referents function.
1892
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001893New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001894-------------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001895
1896C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001897-----
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001898
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001899- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1900 which provide a cross-platform implementations for the
1901 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1902 the standard sprintf() and vsprintf() C lib APIs, these versions
1903 apply bounds checking on the used buffer which enhances protection
1904 against buffer overruns.
1905
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001906- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001907 and extensions using different Unicode widths is rendered next to
1908 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001909 will result in an ImportError. Unicode extensions writers must make
1910 sure to check the Unicode width compatibility in their extensions by
1911 using at least one of the mangled Unicode APIs in the extension.
1912
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001913- Two new flags METH_NOARGS and METH_O are available in method definition
1914 tables to simplify implementation of methods with no arguments and a
1915 single untyped argument. Calling such methods is more efficient than
1916 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1917 deprecated.
1918
Tim Petersc1731372001-08-04 08:12:36 +00001919Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001920-------
Tim Petersc1731372001-08-04 08:12:36 +00001921
1922- "import module" now compiles module.pyw if it exists and nothing else
1923 relevant is found.
1924
Tim Peters20f51a72001-07-21 02:31:40 +00001925
Guido van Rossum55a78992001-07-17 17:22:32 +00001926What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +00001927===========================
1928
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001929*Release date: 18-Jul-2001*
1930
Tim Petersf553f892001-05-01 20:45:31 +00001931Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001932----
Tim Petersa814db52001-05-14 07:05:58 +00001933
Tim Peters6d6c1a32001-08-02 04:15:00 +00001934- TENTATIVELY, a large amount of code implementing much of what's
1935 described in PEP 252 (Making Types Look More Like Classes) and PEP
1936 253 (Subtyping Built-in Types) was added. This will be released
1937 with Python 2.2a1. Documentation will be provided separately
1938 through http://www.python.org/2.2/. The purpose of releasing this
1939 with Python 2.2a1 is to test backwards compatibility. It is
1940 possible, though not likely, that a decision is made not to release
1941 this code as part of 2.2 final, if any serious backwards
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00001942 incompatibilities are found during alpha testing that cannot be
Tim Peters6d6c1a32001-08-02 04:15:00 +00001943 repaired.
1944
Guido van Rossum55a78992001-07-17 17:22:32 +00001945- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001946 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001947 more 'yield' statements. See PEP 255. Since this adds a new
1948 keyword to the language, this feature must be enabled by including a
1949 future statement: "from __future__ import generators" (see PEP 236).
1950 Generators will become a standard feature in a future release
1951 (probably 2.3). Without this future statement, 'yield' remains an
1952 ordinary identifier, but a warning is issued each time it is used.
1953 (These warnings currently don't conform to the warnings framework of
1954 PEP 230; we intend to fix this in 2.2a2.)
1955
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001956- The UTF-16 codec was modified to be more RFC compliant. It will now
1957 only remove BOM characters at the start of the string and then
1958 only if running in native mode (UTF-16-LE and -BE won't remove a
1959 leading BMO character).
1960
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001961- Strings now have a new method .decode() to complement the already
1962 existing .encode() method. These two methods provide direct access
1963 to the corresponding decoders and encoders of the registered codecs.
1964
1965 To enhance the usability of the .encode() method, the special
1966 casing of Unicode object return values was dropped (Unicode objects
1967 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001968
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001969 Both methods will now return whatever the codec in charge of the
1970 requested encoding returns as object, e.g. Unicode codecs will
1971 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1972 will return u"äöü"). This enables codec writer to create codecs
1973 for various simple to use conversions.
1974
1975 New codecs were added to demonstrate these new features (the .encode()
1976 and .decode() columns indicate the type of the returned objects):
1977
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001978 +---------+-----------+-----------+-----------------------------+
1979 |Name | .encode() | .decode() | Description |
1980 +=========+===========+===========+=============================+
1981 |uu | string | string | UU codec (e.g. for email) |
1982 +---------+-----------+-----------+-----------------------------+
1983 |base64 | string | string | base64 codec |
1984 +---------+-----------+-----------+-----------------------------+
1985 |quopri | string | string | quoted-printable codec |
1986 +---------+-----------+-----------+-----------------------------+
1987 |zlib | string | string | zlib compression |
1988 +---------+-----------+-----------+-----------------------------+
1989 |hex | string | string | 2-byte hex codec |
1990 +---------+-----------+-----------+-----------------------------+
1991 |rot-13 | string | Unicode | ROT-13 Unicode charmap codec|
1992 +---------+-----------+-----------+-----------------------------+
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001993
Mark Hammond2a0af792001-05-14 03:09:36 +00001994- Some operating systems now support the concept of a default Unicode
1995 encoding for file system operations. Notably, Windows supports 'mbcs'
1996 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001997 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001998 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001999
2000 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00002001 functions that return filenames (such as os.listdir()) to return Python
2002 string objects pre-encoded using the default file system encoding for
2003 the platform. As this encoding is likely to be different from Python's
2004 default encoding, converting this name to a Unicode object before passing
2005 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00002006 would attempt to use its default encoding (generally ASCII) rather than
2007 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00002008
Tim Petersa814db52001-05-14 07:05:58 +00002009 In general, this change simply removes surprises when working with
2010 Unicode and the file system, making these operations work as you expect,
2011 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00002012 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00002013
Tim Peters61dff2b2001-05-08 15:43:37 +00002014- Float (and complex) literals in source code were evaluated to full
2015 precision only when running from a .py file; the same code loaded from a
2016 .pyc (or .pyo) file could suffer numeric differences starting at about the
2017 12th significant decimal digit. For example, on a machine with IEEE-754
2018 floating arithmetic,
2019
2020 x = 9007199254740992.0
2021 print long(x)
2022
2023 printed 9007199254740992 if run directly from .py, but 9007199254740000
2024 if from a compiled (.pyc or .pyo) file. This was due to marshal using
2025 str(float) instead of repr(float) when building code objects. marshal
2026 now uses repr(float) instead, which should reproduce floats to full
2027 machine precision (assuming the platform C float<->string I/O conversion
2028 functions are of good quality).
2029
2030 This may cause floating-point results to change in some cases, and
2031 usually for the better, but may also cause numerically unstable
2032 algorithms to break.
2033
Tim Peters2f228e72001-05-13 00:19:31 +00002034- The implementation of dicts suffers fewer collisions, which has speed
2035 benefits. However, the order in which dict entries appear in dict.keys(),
2036 dict.values() and dict.items() may differ from previous releases for a
2037 given dict. Nothing is defined about this order, so no program should
2038 rely on it. Nevertheless, it's easy to write test cases that rely on the
2039 order by accident, typically because of printing the str() or repr() of a
2040 dict to an "expected results" file. See Lib/test/test_support.py's new
2041 sortdict(dict) function for a simple way to display a dict in sorted
2042 order.
2043
Tim Peters7a3bfc32001-06-12 01:22:22 +00002044- Many other small changes to dicts were made, resulting in faster
2045 operation along the most common code paths.
2046
Guido van Rossum10315822001-05-01 20:54:30 +00002047- Dictionary objects now support the "in" operator: "x in dict" means
2048 the same as dict.has_key(x).
2049
Barry Warsaw51acc8d2001-06-26 20:12:50 +00002050- The update() method of dictionaries now accepts generic mapping
2051 objects. Specifically the argument object must support the .keys()
2052 and __getitem__() methods. This allows you to say, for example,
2053 {}.update(UserDict())
2054
Guido van Rossum10315822001-05-01 20:54:30 +00002055- Iterators were added; this is a generalized way of providing values
2056 to a for loop. See PEP 234. There's a new built-in function iter()
2057 to return an iterator. There's a new protocol to get the next value
2058 from an iterator using the next() method (in Python) or the
2059 tp_iternext slot (in C). There's a new protocol to get iterators
2060 using the __iter__() method (in Python) or the tp_iter slot (in C).
2061 Iterating (i.e. a for loop) over a dictionary generates its keys.
2062 Iterating over a file generates its lines.
2063
Tim Petersf553f892001-05-01 20:45:31 +00002064- The following functions were generalized to work nicely with iterator
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00002065 arguments::
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002066
Tim Peterse63415e2001-05-08 04:38:29 +00002067 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00002068 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
2069 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00002070 join() method of strings
2071 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00002072 'x in y' and 'x not in y' (PySequence_Contains() in C API)
2073 operator.countOf() (PySequence_Count() in C API)
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002074 right-hand side of assignment statements with multiple targets, such as ::
Tim Petersd6d010b2001-06-21 02:49:55 +00002075 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00002076
Tim Petersd85e1022001-05-11 21:51:48 +00002077- Accessing module attributes is significantly faster (for example,
2078 random.random or os.path or yourPythonModule.yourAttribute).
2079
Tim Peterse63415e2001-05-08 04:38:29 +00002080- Comparing dictionary objects via == and != is faster, and now works even
2081 if the keys and values don't support comparisons other than ==.
2082
Tim Peters95bf9392001-05-10 08:32:44 +00002083- Comparing dictionaries in ways other than == and != is slower: there were
2084 insecurities in the dict comparison implementation that could cause Python
2085 to crash if the element comparison routines for the dict keys and/or
2086 values mutated the dicts. Making the code bulletproof slowed it down.
2087
Tim Peterseb28ef22001-06-02 05:27:19 +00002088- Collisions in dicts are resolved via a new approach, which can help
2089 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00002090 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00002091 faster now. Thanks to Christian Tismer for pointing out the cause and
2092 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00002093
Tim Peters52e155e2001-06-16 05:42:57 +00002094- repr() is much faster for large containers (dict, list, tuple).
2095
2096
Tim Petersa814db52001-05-14 07:05:58 +00002097Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002098-------
Tim Petersa814db52001-05-14 07:05:58 +00002099
Fred Drake960fdf92001-07-20 18:38:26 +00002100- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002101 were added to the string module. These a locale-independent
Fred Drake960fdf92001-07-20 18:38:26 +00002102 constants, unlike letters, lowercase, and uppercase. These are now
2103 use in appropriate locations in the standard library.
2104
Martin v. Löwisf0473d52001-07-18 16:17:16 +00002105- The flags used in dlopen calls can now be configured using
2106 sys.setdlopenflags and queried using sys.getdlopenflags.
2107
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00002108- Fredrik Lundh's xmlrpclib is now a standard library module. This
2109 provides full client-side XML-RPC support. In addition,
2110 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
2111 one asyncore-based). Thanks to Eric Raymond for the documentation.
2112
Guido van Rossum643d3912001-07-05 14:46:25 +00002113- The xrange() object is simplified: it no longer supports slicing,
2114 repetition, comparisons, efficient 'in' checking, the tolist()
2115 method, or the start, stop and step attributes. See PEP 260.
2116
Martin v. Löwisebf94db2001-06-06 06:25:40 +00002117- A new function fnmatch.filter to filter lists of file names was added.
2118
Barry Warsawffd674d2001-05-22 16:00:10 +00002119- calendar.py uses month and day names based on the current locale.
2120
Guido van Rossum2e0a6542001-05-15 02:14:44 +00002121- strop is now *really* obsolete (this was announced before with 1.6),
2122 and issues DeprecationWarning when used (except for the four items
2123 that are still imported into string.py).
2124
Tim Petersa814db52001-05-14 07:05:58 +00002125- Cookie.py now sorts key+value pairs by key in output strings.
2126
2127- pprint.isrecursive(object) didn't correctly identify recursive objects.
2128 Now it does.
2129
Tim Peters95b3f782001-05-14 18:39:41 +00002130- pprint functions now much faster for large containers (tuple, list, dict).
2131
Tim Peters7b9542a2001-06-10 23:40:19 +00002132- New 'q' and 'Q' format codes in the struct module, corresponding to C
2133 types "long long" and "unsigned long long" (on Windows, __int64). In
2134 native mode, these can be used only when the platform C compiler supports
2135 these types (when HAVE_LONG_LONG is #define'd by the Python config
2136 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00002137 In standard mode, 'q' and 'Q' are supported on all platforms, and are
2138 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00002139
Guido van Rossum83213cc2001-06-12 16:48:52 +00002140- The site module installs a new built-in function 'help' that invokes
2141 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
2142 it displays a message reminding the user to use 'help()' or
2143 'help(object)'.
2144
Tim Petersa814db52001-05-14 07:05:58 +00002145Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002146-----
Tim Petersa814db52001-05-14 07:05:58 +00002147
2148- New test_mutants.py runs dict comparisons where the key and value
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002149 comparison operators mutate the dicts randomly during comparison. This
Tim Petersa814db52001-05-14 07:05:58 +00002150 rapidly causes Python to crash under earlier releases (not for the faint
2151 of heart: it can also cause Win9x to freeze or reboot!).
2152
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002153- New test_pprint.py verifies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00002154 pprint.isreadable() return sensible results. Also verifies that simple
2155 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00002156
Tim Peters4324aa32001-05-28 22:30:08 +00002157C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002158-----
Tim Peters4324aa32001-05-28 22:30:08 +00002159
2160- Removed the unused last_is_sticky argument from the internal
2161 _PyTuple_Resize(). If this affects you, you were cheating.
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002162
2163----
2164
2165**(For information about older versions, consult the HISTORY file.)**