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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.
70
Walter Dörwald3aeb6322002-09-02 13:14:32 +000071- Codec error handling callbacks (PEP 293) are implemented.
72 Error handling in unicode.encode or str.decode can now be customized.
73
Guido van Rossum45ec02a2002-08-19 21:43:18 +000074- A subtle change to the semantics of the built-in function intern():
75 interned strings are no longer immortal. You must keep a reference
76 to the return value intern() around to get the benefit.
77
Guido van Rossumf808b892002-08-16 03:38:10 +000078- Use of 'None' as a variable, argument or attribute name now
79 issues a SyntaxWarning. In the future, None may become a keyword.
80
Michael W. Hudsondd32a912002-08-15 14:59:02 +000081- SET_LINENO is gone. co_lnotab is now consulted to determine when to
82 call the trace function. C code that accessed f_lineno should call
83 PyCode_Addr2Line instead (f_lineno is still there, but not kept up
84 to date).
85
Guido van Rossum9be89462002-08-14 16:11:30 +000086- There's a new warning category, FutureWarning. This is used to warn
87 about a number of situations where the value or sign of an integer
88 result will change in Python 2.4 as a result of PEP 237 (integer
89 unification). The warnings implement stage B0 mentioned in that
90 PEP. The warnings are about the following situations:
91
92 - Octal and hex literals without 'L' prefix in the inclusive range
93 [0x80000000..0xffffffff]; these are currently negative ints, but
94 in Python 2.4 they will be positive longs with the same bit
95 pattern.
96
97 - Left shifts on integer values that cause the outcome to lose
98 bits or have a different sign than the left operand. To be
99 precise: x<<n where this currently doesn't yield the same value
100 as long(x)<<n; in Python 2.4, the outcome will be long(x)<<n.
101
102 - Conversions from ints to string that show negative values as
103 unsigned ints in the inclusive range [0x80000000..0xffffffff];
104 this affects the functions hex() and oct(), and the string
105 formatting codes %u, %o, %x, and %X. In Python 2.4, these will
106 show signed values (e.g. hex(-1) currently returns "0xffffffff";
107 in Python 2.4 it will return "-0x1").
108
Skip Montanaro979c74b2002-09-03 21:25:14 +0000109 - The bits manipulated under the cover by sys.setcheckinterval() have
110 been changed. Both the check interval and the ticker used to be
111 per-thread values. They are now just a pair of global variables. In
112 addition, the default check interval was boosted from 10 to 100
Neal Norwitz7165af22002-09-05 21:42:24 +0000113 bytecode instructions. This may have some effect on systems that
114 relied on the old default value. In particular, in multi-threaded
115 applications which try to be highly responsive, response time will
116 increase by some (perhaps imperceptible) amount.
Skip Montanaro979c74b2002-09-03 21:25:14 +0000117
Tim Petersd64c1de2002-08-12 17:36:03 +0000118- When multiplying very large integers, a version of the so-called
119 Karatsuba algorithm is now used. This is most effective if the
120 inputs have roughly the same size. If they both have about N digits,
121 Karatsuba multiplication has O(N**1.58) runtime (the exponent is
122 log_base_2(3)) instead of the previous O(N**2). Measured results may
Tim Peters012c0a32002-08-16 03:40:07 +0000123 be better or worse than that, depending on platform quirks. Besides
124 the O() improvement in raw instruction count, the Karatsuba algorithm
125 appears to have much better cache behavior on extremely large integers
126 (starting in the ballpark of a million bits). Note that this is a
127 simple implementation, and there's no intent here to compete with,
128 e.g., GMP. It gives a very nice speedup when it applies, but a package
129 devoted to fast large-integer arithmetic should run circles around it.
Tim Peters5af4e6c2002-08-12 02:31:19 +0000130
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000131- u'%c' will now raise a ValueError in case the argument is an
132 integer outside the valid range of Unicode code point ordinals.
133
Guido van Rossumdeb09362002-08-09 17:16:30 +0000134- The tempfile module has been overhauled for enhanced security. The
135 mktemp() function is now deprecated; new, safe replacements are
136 mkstemp() (for files) and mkdtemp() (for directories), and the
137 higher-level functions NamedTemporaryFile() and TemporaryFile().
138 Use of some global variables in this module is also deprecated; the
139 new functions have keyword arguments to provide the same
140 functionality. All Lib, Tools and Demo modules that used the unsafe
141 interfaces have been updated to use the safe replacements. Thanks
142 to Zack Weinberg!
143
Guido van Rossumd81a9832002-08-09 15:57:34 +0000144- When x is an object whose class implements __mul__ and __rmul__,
145 1.0*x would correctly invoke __rmul__, but 1*x would erroneously
146 invoke __mul__. This was due to the sequence-repeat code in the int
147 type. This has been fixed now.
148
Barry Warsawd79f6832002-08-06 17:01:51 +0000149- Previously, "str1 in str2" required str1 to be a string of length 1.
150 This restriction has been relaxed to allow str1 to be a string of
151 any length. Thus "'el' in 'hello world'" returns True now.
152
Guido van Rossumb57089c2002-08-06 16:20:26 +0000153- File objects are now their own iterators. For a file f, iter(f) now
154 returns f (unless f is closed), and f.next() is similar to
155 f.readline() when EOF is not reached; however, f.next() uses a
156 readahead buffer that messes up the file position, so mixing
157 f.next() and f.readline() (or other methods) doesn't work right.
158 Calling f.seek() drops the readahead buffer, but other operations
159 don't. It so happens that this gives a nice additional speed boost
160 to "for line in file:"; the xreadlines method and corresponding
Guido van Rossumbffb2ef2002-08-09 17:17:07 +0000161 module are now obsolete. Thanks to Oren Tirosh!
Guido van Rossumb57089c2002-08-06 16:20:26 +0000162
Guido van Rossumde392d32002-08-05 14:17:20 +0000163- Encoding declarations (PEP 263, phase 1) have been implemented. A
164 comment of the form "# -*- coding: <encodingname> -*-" in the first
165 or second line of a Python source file indicates the encoding.
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +0000166
Tim Petersf47630f2002-08-01 02:34:51 +0000167- list.sort() has a new implementation. While cross-platform results
168 may vary, and in data-dependent ways, this is much faster on many
169 kinds of partially ordered lists than the previous implementation,
170 and reported to be just as fast on randomly ordered lists on
171 several major platforms. This sort is also stable (if A==B and A
172 precedes B in the list at the start, A precedes B after the sort too),
173 although the language definition does not guarantee stability. A
174 potential drawback is that list.sort() may require temp space of
Skip Montanaroa2a07bc2002-09-30 15:23:01 +0000175 len(list)*2 bytes (``*4`` on a 64-bit machine). It's therefore possible
Tim Petersf47630f2002-08-01 02:34:51 +0000176 for list.sort() to raise MemoryError now, even if a comparison function
177 does not. See <http://www.python.org/sf/587076> for full details.
178
Guido van Rossum2d5389c2002-07-23 03:44:35 +0000179- All standard iterators now ensure that, once StopIteration has been
180 raised, all future calls to next() on the same iterator will also
181 raise StopIteration. There used to be various counterexamples to
182 this behavior, which could caused confusion or subtle program
183 breakage, without any benefits. (Note that this is still an
184 iterator's responsibility; the iterator framework does not enforce
185 this.)
186
Mark Hammondc0e35152002-07-16 01:32:30 +0000187- Ctrl+C handling on Windows has been made more consistent with
188 other platforms. KeyboardInterrupt can now reliably be caught,
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +0000189 and Ctrl+C at an interactive prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +0000190 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Peters5af4e6c2002-08-12 02:31:19 +0000191 interrupt time.sleep() in the main thread, and any child processes
192 created via the popen family (on win2k; we can't make win9x work
Mark Hammond8f3afc72002-08-10 06:26:31 +0000193 reliably) are also interrupted (as generally happens on for Linux/Unix.)
194 [SF bugs 231273, 439992 and 581232]
Mark Hammondc0e35152002-07-16 01:32:30 +0000195
Raymond Hettinger5a04aec2002-06-25 00:25:30 +0000196- Slices and repetitions of buffer objects now consistently return
197 a string. Formerly, strings would be returned most of the time,
198 but a buffer object would be returned when the repetition count
199 was one or when the slice range was all inclusive.
200
Walter Dörwald3430d702002-06-17 10:43:59 +0000201- Unicode objects in sys.path are no longer ignored but treated
202 as directory names.
203
Neal Norwitz1f68fc72002-06-14 00:50:42 +0000204- Fixed string.startswith and string.endswith builtin methods
205 so they accept negative indices. [SF bug 493951]
206
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +0000207- Fixed a bug with a continue inside a try block and a yield in the
208 finally clause. [SF bug 567538]
209
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +0000210- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +0000211 with a third "stride" parameter. For example, "hello world"[::-1]
212 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +0000213
Neal Norwitzd68f5172002-05-29 15:54:55 +0000214- A new warning PendingDeprecationWarning was added to provide
215 direction on features which are in the process of being deprecated.
216 The warning will not be printed by default. To see the pending
217 deprecations, use -Walways::PendingDeprecationWarning::
218 as a command line option or warnings.filterwarnings() in code.
219
Fred Draked0ba6362002-05-02 21:28:26 +0000220- Deprecated features of xrange objects have been removed as
221 promised. The start, stop, and step attributes and the tolist()
222 method no longer exist. xrange repetition and slicing have been
223 removed.
224
Guido van Rossum7dab2422002-04-26 19:40:56 +0000225- New builtin function enumerate(x), from PEP 279. Example:
226 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
227 The argument can be an arbitrary iterable object.
228
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000229- The assert statement no longer tests __debug__ at runtime. This means
230 that assert statements cannot be disabled by assigning a false value
231 to __debug__.
232
Walter Dörwald068325e2002-04-15 13:36:47 +0000233- A method zfill() was added to str and unicode, that fills a numeric
234 string to the left with zeros. For example,
235 "+123".zfill(6) -> "+00123".
236
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000237- Complex numbers supported divmod() and the // and % operators, but
238 these make no sense. Since this was documented, they're being
239 deprecated now.
240
Guido van Rossum26dd8302002-04-26 20:11:29 +0000241- String and unicode methods lstrip(), rstrip() and strip() now take
242 an optional argument that specifies the characters to strip. For
243 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000244
Guido van Rossumc69343b2002-04-12 19:22:48 +0000245- Added a new dict method pop(key). This removes and returns the
246 value corresponding to key. [SF patch #539949]
247
Guido van Rossum47834462002-04-04 15:21:33 +0000248- A new built-in type, bool, has been added, as well as built-in
249 names for its two values, True and False. Comparisons and sundry
250 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000251 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000252 is backward compatible.
253
Guido van Rossum95b62a62002-03-29 01:07:24 +0000254- Fixed two bugs reported as SF #535905: under certain conditions,
255 deallocating a deeply nested structure could cause a segfault in the
256 garbage collector, due to interaction with the "trashcan" code;
257 access to the current frame during destruction of a local variable
258 could access a pointer to freed memory.
259
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000260- The optional object allocator ("pymalloc") has been enabled by
261 default. The recommended practice for memory allocation and
262 deallocation has been streamlined. A header file is included,
263 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
264 and lets them use the same API with Python versions from 1.5.2
265 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000266
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000267- PyErr_Display will provide file and line information for all exceptions
268 that have an attribute print_file_and_line, not just SyntaxErrors.
269
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000270- The UTF-8 codec will now encode and decode Unicode surrogates
271 correctly and without raising exceptions for unpaired ones.
272
Guido van Rossumadd88062002-08-15 14:01:14 +0000273- Universal newlines (PEP 278) is implemented. Briefly, using 'U'
274 instead of 'r' when opening a text file for reading changes the line
275 ending convention so that any of '\r', '\r\n', and '\n' is
276 recognized (even mixed in one file); all three are converted to
277 '\n', the standard Python line end character.
278
Neal Norwitz649b7592002-01-01 19:07:13 +0000279- file.xreadlines() now raises a ValueError if the file is closed:
280 Previously, an xreadlines object was returned which would raise
281 a ValueError when the xreadlines.next() method was called.
282
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000283- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000284 An exception will now be raised if more than one argument is used.
285
Tim Petersaf8446f2001-12-21 21:36:50 +0000286Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000287-----------------
Tim Petersaf8446f2001-12-21 21:36:50 +0000288
Guido van Rossumba602972002-10-01 18:18:58 +0000289- The _tkinter module (and hence Tkinter) has dropped support for
290 Tcl/Tk 8.0 and 8.1. Only Tcl/Tk versions 8.2, 8.3 and 8.4 are
291 supported.
292
Martin v. Löwis658009a2002-09-16 17:26:24 +0000293- cPickle.BadPickleGet is now a class.
294
Martin v. Löwisa32c9942002-09-09 16:17:47 +0000295- The time stamps in os.stat_result are floating point numbers now.
Martin v. Löwis94717ed2002-09-09 14:24:16 +0000296
Neal Norwitzb5673922002-09-05 21:48:07 +0000297- If the size passed to mmap.mmap() is larger than the length of the
298 file on non-Windows platforms, a ValueError is raised. [SF bug 585792]
299
Guido van Rossumb57089c2002-08-06 16:20:26 +0000300- The xreadlines module is slated for obsolescence.
301
Guido van Rossum79f0a102002-07-23 03:32:08 +0000302- The strptime function in the time module is now always available (a
303 Python implementation is used when the C library doesn't define it).
304
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000305- The 'new' module is no longer an extension, but a Python module that
306 only exists for backwards compatibility. Its contents are no longer
307 functions but callable type objects.
308
Tim Peters81b92512002-04-29 01:37:32 +0000309- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000310 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000311 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000312
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000313- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
314 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000315
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000316- The locale module now exposes the C library's gettext interface.
317
Tim Petersfbf74f22002-03-14 19:06:01 +0000318- A security hole ("double free") was found in zlib-1.1.3, a popular
319 third party compression library used by some Python modules. The
320 hole was quickly plugged in zlib-1.1.4, and the Windows build of
321 Python now ships with zlib-1.1.4.
322
Martin v. Löwis688357e2002-04-08 21:28:20 +0000323- pwd, grp, and resource return enhanced tuples now, with symbolic
324 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000325
Martin v. Löwis99866332002-03-01 10:27:01 +0000326- array.array is now a type object. A new format character
327 'u' indicates Py_UNICODE arrays. For those, .tounicode and
328 .fromunicode methods are available. Arrays now support __iadd__
329 and __imul__.
330
Neal Norwitze790eae2002-01-01 21:14:12 +0000331- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000332 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
333 is called.
334
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000335- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
336 been added where available.
337
Skip Montanaro8e790e72002-09-03 13:25:17 +0000338- The sys module acquired a new attribute, api_version, which evaluates
339 to the value of the PYTHON_API_VERSION macro with which the
340 interpreter was compiled.
341
Tim Petersaf8446f2001-12-21 21:36:50 +0000342Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000343-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000344
Marc-André Lemburg97047e22002-10-04 11:55:21 +0000345- Encoding name normalization was generalized to not only
346 replace hyphens with underscores, but also all other non-alphanumeric
347 characters (with the exception of the dot which is used for Python
348 package names during lookup). The aliases.py mapping was updated
349 to the new standard.
350
Walter Dörwald5ccaf8f2002-09-06 16:15:58 +0000351- mimetypes has two new functions: guess_all_extensions() which
352 returns a list of all known extensions for a mime type, and
353 add_type() which adds one mapping between a mime type and
354 an extension to the database.
355
Guido van Rossumd8ab35c2002-08-19 16:25:46 +0000356- New module: sets, defines the class Set that implements a mutable
357 set type using the keys of a dict to represent the set. There's
358 also a class ImmutableSet which is useful when you need sets of sets
359 or when you need to use sets as dict keys, and a class BaseSet which
360 is the base class of the two. (This is not documented yet, but
361 help(sets) gives a wealth of information.)
362
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +0000363- Added operator.pow(a,b) which is equivalent to a**b.
364
Tim Peters012c0a32002-08-16 03:40:07 +0000365- random.randrange(-sys.maxint-1, sys.maxint) no longer raises
366 OverflowError. That is, it now accepts any combination of 'start'
367 and 'stop' arguments so long as each is in the range of Python's
368 bounded integers.
369
Guido van Rossum4a57c332002-08-02 18:05:20 +0000370- New "algorithms" module: heapq, implements a heap queue. Thanks to
371 Kevin O'Connor for the code and François Pinard for an entertaining
372 write-up explaining the theory and practical uses of heaps.
373
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000374- New encoding for the Palm OS character set: palmos.
375
Tim Peters943382c2002-07-07 03:59:34 +0000376- binascii.crc32() and the zipfile module had problems on some 64-bit
377 platforms. These have been fixed. On a platform with 8-byte C longs,
378 crc32() now returns a signed-extended 4-byte result, so that its value
379 as a Python int is equal to the value computed a 32-bit platform.
380
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000381- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
382 argument.
383
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000384- Some fixes in the copy module: when an object is copied through its
385 __reduce__ method, there was no check for a __setstate__ method on
386 the result [SF patch 565085]; deepcopy should treat instances of
387 custom metaclasses the same way it treats instances of type 'type'
388 [SF patch 560794].
389
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000390- Sockets now support timeout mode. After s.settimeout(T), where T is
391 a float expressing seconds, subsequent operations raise an exception
392 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000393 mode, use s.settimeout(None). There's also a module function,
394 socket.setdefaulttimeout(T), which sets the default for all sockets
395 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000396
397- getopt.gnu_getopt was added. This supports GNU-style option
398 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000399
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000400- Stop using strings for exceptions. String objects used for
401 exceptions are now classes deriving from Exception. The objects
402 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
403 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000404
Walter Dörwald474458d2002-06-04 15:16:29 +0000405- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
406 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
407 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
408 big endian systems were added to the codecs module. The old names
409 BOM32_* and BOM64_* were off by a factor of 2.
410
Guido van Rossumf9257822002-06-18 20:43:18 +0000411- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000412
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000413- ftplib.retrlines() now tests for callback is None rather than testing
414 for False. Was causing an error when given a callback object which
415 was callable but also returned len() as zero. The change may
416 create new breakage if the caller relied on the undocumented behavior
417 and called with callback set to [] or some other False value not
418 identical to None.
419
Tim Peters46c04e12002-05-05 20:40:00 +0000420- random.gauss() uses a piece of hidden state used by nothing else,
421 and the .seed() and .whseed() methods failed to reset it. In other
422 words, setting the seed didn't completely determine the sequence of
423 results produced by random.gauss(). It does now. Programs repeatedly
424 mixing calls to a seed method with calls to gauss() may see different
425 results now.
426
Fred Drake7f781c92002-05-01 20:33:53 +0000427- The pickle.Pickler class grew a clear_memo() method to mimic that
428 provided by cPickle.Pickler.
429
Tim Peters81b92512002-04-29 01:37:32 +0000430- difflib's SequenceMatcher class now does a dynamic analysis of
431 which elements are so frequent as to constitute noise. For
432 comparing files as sequences of lines, this generally works better
433 than the IS_LINE_JUNK function, and function ndiff's linejunk
434 argument defaults to None now as a result. A happy benefit is
435 that SequenceMatcher may run much faster now when applied
436 to large files with many duplicate lines (for example, C program
437 text with lots of repeated "}" and "return NULL;" lines).
438
Guido van Rossum256705b2002-04-23 13:29:43 +0000439- New Text.dump() method in Tkinter module.
440
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000441- New distutils commands for building packagers were added to
442 support pkgtool on Solaris and swinstall on HP-UX.
443
444- distutils now has a new abstract binary packager base class
445 command/bdist_packager, which simplifies writing packagers.
446 This will hopefully provide the missing bits to encourage
447 people to submit more packagers, e.g. for Debian, FreeBSD
448 and other systems.
449
Guido van Rossumf9257822002-06-18 20:43:18 +0000450- The UTF-16, -LE and -BE stream readers now raise a
451 NotImplementedError for all calls to .readline(). Previously, they
452 used to just produce garbage or fail with an encoding error --
453 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 +0000454 work well with these.
455
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000456- compileall now supports quiet operation.
457
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000458- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000459 connections.
460
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000461- socket module: the SSL support was broken out of the main
462 _socket module C helper and placed into a new _ssl helper
463 which now gets imported by socket.py if available and working.
464
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000465- encodings package: added aliases for all supported IANA character
466 sets
467
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000468- ftplib: to safeguard the user's privacy, anonymous login will use
469 "anonymous@" as default password, rather than the real user and host
470 name.
471
Fred Drake36736122002-01-10 13:50:31 +0000472- webbrowser: tightened up the command passed to os.system() so that
473 arbitrary shell code can't be executed because a bogus URL was
474 passed in.
475
Tim Peters11bd9942002-02-01 00:52:29 +0000476- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000477 gettext.find an optional all argument. Translations will now fallback
478 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000479
Martin v. Löwis9668b932002-01-12 11:27:42 +0000480- distutils bdist commands now offer a --skip-build option.
481
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000482- warnings.warn now accepts a Warning instance as first argument.
483
Fred Drakefed7e852002-04-04 19:36:15 +0000484- The xml.sax.expatreader.ExpatParser class will no longer create
485 circular references by using itself as the locator that gets passed
486 to the content handler implementation. [SF bug #535474]
487
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000488- The email.Parser.Parser class now properly parses strings regardless
489 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
490 or CRLF). Also, the Header class's constructor default arguments
491 has changed slightly so that an explicit maxlinelen value is always
492 honored.
493
Tim Petersaf8446f2001-12-21 21:36:50 +0000494Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000495-----------
Tim Petersaf8446f2001-12-21 21:36:50 +0000496
Guido van Rossum923e4ef2002-09-17 20:58:59 +0000497- The SGI demos (Demo/sgi) have been removed. Nobody thought they
498 were interesting any more. (The SGI library modules and extensions
499 are still there; it is believed that at least some of these are
500 still used and useful.)
501
Fred Drake40813b12002-08-05 15:24:19 +0000502- IDLE supports the new encoding declarations (PEP 263); it can also
503 deal with legacy 8-bit files if they use the locale's encoding. It
504 allows non-ASCII strings in the interactive shell and executes them
505 in the locale's encoding.
Martin v. Löwis98ce7b72002-08-05 15:11:26 +0000506
Marc-André Lemburg46260092002-04-04 16:17:11 +0000507- freeze.py now produces binaries which can import shared modules,
508 unlike before when this failed due to missing symbol exports in
509 the generated binary.
510
Tim Petersaf8446f2001-12-21 21:36:50 +0000511Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000512-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000513
Guido van Rossum6b3db552002-09-25 15:02:44 +0000514- The fpectl module is not built by default; it's dangerous or useless
515 except in the hands of experts.
516
Tim Petersf47630f2002-08-01 02:34:51 +0000517- The public Python C API will generally be declared using PyAPI_FUNC
Guido van Rossum6b3db552002-09-25 15:02:44 +0000518 and PyAPI_DATA macros, while Python extension module init functions
519 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
520 are deprecated.
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000521
Tim Petersc6a3ff62002-07-08 22:11:52 +0000522- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
523 get into infinite loops, when a new-style class got garbage-collected.
524 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
525 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
526 COUNT_ALLOCS is not enabled by default, in either release or debug
527 builds, and that new-style classes are immortal only in COUNT_ALLOCS
528 builds.
529
Tim Peters943382c2002-07-07 03:59:34 +0000530- Compiling out the cyclic garbage collector is no longer an option.
531 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
532 that it's always defined (for the benefit of any extension modules
533 that may be conditionalizing on it). A bonus is that any extension
534 type participating in cyclic gc can choose to participate in the
535 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
536 to require editing the core to teach the trashcan mechanism about the
537 new type.
538
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000539- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000540
541 The Standard C macro HUGE_VAL and its float and long double analogs,
542 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
543 positive infinities.
544
545 Python only uses the double HUGE_VAL, and only to #define its own symbol
546 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
547 pyport.h used to try to worm around that, but the workarounds triggered
548 other bugs on other platforms, so we gave up. If your platform defines
549 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
550 that works on your platform. The only instance of this I'm sure about
551 is on an unknown subset of Cray systems, described here:
552
553 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
554
555 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
556
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000557- The configure option --without-doc-strings can be used to remove the
558 doc strings from the builtin functions and modules; this reduces the
559 size of the executable.
560
Guido van Rossumadd88062002-08-15 14:01:14 +0000561- The universal newlines option (PEP 278) is on by default. On Unix
562 it can be disabled by passing --without-universal-newlines to the
563 configure script. On other platforms, remove
564 WITH_UNIVERSAL_NEWLINES from pyconfig.h.
Tim Peters639295f2002-04-21 07:30:30 +0000565
Martin v. Löwis1142de32002-03-29 16:28:31 +0000566- On Unix, a shared libpython2.3.so can be created with --enable-shared.
567
Tim Peters8deda702002-03-30 10:06:07 +0000568- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
569 preprocessor symbols were eliminated. The internal decisions they
570 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000571
Fred Drake7d28b732002-05-02 21:17:00 +0000572- The tools used to build the documentation now work under Cygwin as
573 well as Unix.
574
Skip Montanaro57454e52002-06-14 20:30:31 +0000575- The bsddb and dbm module builds have been changed to try and avoid version
576 skew problems and disable linkage with Berkeley DB 1.85 unless the
577 installer knows what s/he's doing. See the section on building these
578 modules in the README file for details.
579
Tim Petersaf8446f2001-12-21 21:36:50 +0000580C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000581-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000582
Guido van Rossum45ec02a2002-08-19 21:43:18 +0000583- The string object's layout has changed: the pointer member
584 ob_sinterned has been replaced by an int member ob_sstate. On some
585 platforms (e.g. most 64-bit systems) this may change the offset of
586 the ob_sval member, so as a precaution the API_VERSION has been
587 incremented. The apparently unused feature of "indirect interned
588 strings", supported by the ob_sinterned member, is gone. Interned
589 strings are now usually mortal; theres a new API,
590 PyString_InternImmortal() that creates immortal interned strings.
591 (The ob_sstate member can only take three values; however, while
592 making it a char saves a few bytes per string object on average, in
593 it also slowed things down a bit because ob_sval was no longer
594 aligned.)
595
Guido van Rossumfdb86482002-08-14 21:20:32 +0000596- The Py_InitModule*() functions now accept NULL for the 'methods'
597 argument. Modules without global functions are becoming more common
598 now that factories can be types rather than functions.
599
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000600- New C API PyUnicode_FromOrdinal() which exposes unichr() at C
601 level.
602
Thomas Heller085358a2002-07-29 14:27:41 +0000603- New functions PyErr_SetExcFromWindowsErr() and
604 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
605 PyErr_SetFromWindowsErrWithFilename() and
606 PyErr_SetFromWindowsErr(), but they allow to specify
607 the exception type to raise. Available on Windows.
608
Tim Peters7c321a82002-07-09 02:57:01 +0000609- Py_FatalError() is now declared as taking a const char* argument. It
610 was previously declared without const. This should not affect working
611 code.
612
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000613- Added new macro PySequence_ITEM(o, i) that directly calls
614 sq_item without rechecking that o is a sequence and without
615 adjusting for negative indices.
616
Fred Draked0ba6362002-05-02 21:28:26 +0000617- PyRange_New() now raises ValueError if the fourth argument is not 1.
618 This is part of the removal of deprecated features of the xrange
619 object.
620
Guido van Rossum517c7d42002-04-26 02:49:14 +0000621- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
622 coercion if both arguments have the same type but this type has the
623 CHECKTYPES flag set. This is to better support proxies.
624
Skip Montanaroa2a07bc2002-09-30 15:23:01 +0000625- The type of tp_free has been changed from "``void (*)(PyObject *)``" to
626 "``void (*)(void *)``".
Neil Schemenauer9344b142002-04-12 23:00:08 +0000627
628- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
629
Guido van Rossum0986d822002-04-08 01:38:42 +0000630- A type can now inherit its metatype from its base type. Previously,
631 when PyType_Ready() was called, if ob_type was found to be NULL, it
632 was always set to &PyType_Type; now it is set to base->ob_type,
633 where base is tp_base, defaulting to &PyObject_Type.
634
635- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
636
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000637- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000638
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000639- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000640 without going through the buffer API.
641
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000642- The enumerators of cmp_op have been renamed to use the prefix ``PyCmp_``.
Martin v. Löwis7198a522002-01-01 19:59:11 +0000643
Tim Peters10a3bb52001-12-25 19:07:38 +0000644- An old #define of ANY as void has been removed from pyport.h. This
645 hasn't been used since Python's pre-ANSI days, and the #define has
646 been marked as obsolete since then. SF bug 495548 says it created
647 conflicts with other packages, so keeping it around wasn't harmless.
648
Tim Petersaf8446f2001-12-21 21:36:50 +0000649- Because Python's magic number scheme broke on January 1st, we decided
650 to stop Python development. Thanks for all the fish!
651
Tim Petersfb05db22002-03-11 00:24:00 +0000652- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000653 scheme to a new one. See Python/import.c for details.
654
Tim Petersaf8446f2001-12-21 21:36:50 +0000655New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000656-------------
Tim Petersaf8446f2001-12-21 21:36:50 +0000657
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000658- AtheOS is now supported.
659
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000660- the EMX runtime environment on OS/2 is now supported.
661
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000662- GNU/Hurd is now supported.
663
Tim Petersaf8446f2001-12-21 21:36:50 +0000664Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000665-----
666
667Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000668
669Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000670-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000671
Tim Peters08e72952002-04-16 20:48:01 +0000672- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
673 of that has been fixed in the installer (disabled Wise's "delete in-
674 use files" uninstall option).
675
Guido van Rossum181e41a2002-04-06 00:23:25 +0000676- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
677
Tim Peters33187922002-04-04 20:02:04 +0000678- The installer now installs Start menu shortcuts under (the local
679 equivalent of) "All Users" when doing an Admin install.
680
Tim Petersfb05db22002-03-11 00:24:00 +0000681- file.truncate([newsize]) now works on Windows for all newsize values.
682 It used to fail if newsize didn't fit in 32 bits, reflecting a
683 limitation of MS _chsize (which is no longer used).
684
Tim Petersab034fa2002-02-01 11:27:43 +0000685- os.waitpid() is now implemented for Windows, and can be used to block
686 until a specified process exits. This is similar to, but not exactly
687 the same as, os.waitpid() on POSIX systems. If you're waiting for
688 a specific process whose pid was obtained from one of the spawn()
689 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000690 See the docs for details. The docs were changed to clarify that
691 spawn functions return, and waitpid requires, a process handle on
692 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000693
Tim Peters11bd9942002-02-01 00:52:29 +0000694- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000695 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000696 to a nasty problem: before 2.3, if you got a temp file on Windows, it
697 got wrapped in an object whose close() method first closed the
698 underlying file, then deleted the file. This usually worked fine.
699 However, the spawn family of functions on Windows create (at a low C
700 level) the same set of open files in the spawned process Q as were
701 open in the spawning process P. If a temp file f was among them, then
702 doing f.close() in P first closed P's C-level file handle on f, but Q's
703 C-level file handle on f remained open, so the attempt in P to delete f
704 blew up with a "Permission denied" error (Windows doesn't allow
705 deleting open files). This was surprising, subtle, and difficult to
706 work around.
707
708- The os module now exports all the symbolic constants usable with the
709 low-level os.open() on Windows: the new constants in 2.3 are
710 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
711 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
712 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
713 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
714 (so specify both if you want both; note that neither is useful unless
715 specified with O_CREAT too).
716
Tim Petersaf8446f2001-12-21 21:36:50 +0000717Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000718----
719
720Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000721
722
Tim Peters909c0912001-12-14 23:16:18 +0000723What's New in Python 2.2 final?
Tim Peters909c0912001-12-14 23:16:18 +0000724===============================
725
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000726*Release date: 21-Dec-2001*
727
Tim Peters909c0912001-12-14 23:16:18 +0000728Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000729--------------------------------------------
Tim Peters909c0912001-12-14 23:16:18 +0000730
Barry Warsaw52acb492001-12-21 20:04:22 +0000731- pickle.py, cPickle: allow pickling instances of new-style classes
732 with a custom metaclass.
733
Tim Peters909c0912001-12-14 23:16:18 +0000734Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000735-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000736
Barry Warsaw52acb492001-12-21 20:04:22 +0000737- weakref proxy object: when comparing, unwrap both arguments if both
738 are proxies.
739
Tim Peters909c0912001-12-14 23:16:18 +0000740Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000741-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000742
Barry Warsaw52acb492001-12-21 20:04:22 +0000743- binascii.b2a_base64(): fix a potential buffer overrun when encoding
744 very short strings.
745
746- cPickle: the obscure "fast" mode was suspected of causing stack
747 overflows on the Mac. Hopefully fixed this by setting the recursion
748 limit much smaller. If the limit is too low (it only affects
749 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
750 when compiling cPickle.c (or in pyconfig.h).
751
Tim Peters909c0912001-12-14 23:16:18 +0000752Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000753-------
Tim Peters909c0912001-12-14 23:16:18 +0000754
Barry Warsaw52acb492001-12-21 20:04:22 +0000755- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
756 close or delete time).
757
758- rfc822.py: fixed a bug where the address '<>' was converted to None
759 instead of an empty string (also fixes the email.Utils module).
760
761- xmlrpclib.py: version 1.0.0; uses precision for doubles.
762
763- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000764 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000765
Tim Peters909c0912001-12-14 23:16:18 +0000766Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000767-----------
Tim Peters909c0912001-12-14 23:16:18 +0000768
769Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000770-----
Tim Peters909c0912001-12-14 23:16:18 +0000771
772C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000773-----
Tim Peters909c0912001-12-14 23:16:18 +0000774
775New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000776-------------
Tim Peters909c0912001-12-14 23:16:18 +0000777
778Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000779-----
Tim Peters909c0912001-12-14 23:16:18 +0000780
781Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000782-------
Tim Peters909c0912001-12-14 23:16:18 +0000783
Barry Warsaw52acb492001-12-21 20:04:22 +0000784- distutils package: fixed broken Windows installers (bdist_wininst).
785
786- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
787 instances are deleted at process exit time.
788
789- socket.py: prevent mysterious warnings when socket instances are
790 deleted at process exit time.
791
792- posixmodule.c: fix a Windows crash with stat() of a filename ending
793 in backslash.
794
Tim Peters909c0912001-12-14 23:16:18 +0000795Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000796----
Tim Peters909c0912001-12-14 23:16:18 +0000797
Barry Warsaw52acb492001-12-21 20:04:22 +0000798- The Carbon toolbox modules have been upgraded to Universal Headers
799 3.4, and experimental CoreGraphics and CarbonEvents modules have
800 been added. All only for framework-enabled MacOSX.
801
Tim Peters909c0912001-12-14 23:16:18 +0000802
Tim Peters6272dfd2001-12-13 19:34:00 +0000803What's New in Python 2.2c1?
Tim Petersb3c9af12001-11-17 00:21:57 +0000804===========================
805
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000806*Release date: 14-Dec-2001*
807
Tim Petersb3c9af12001-11-17 00:21:57 +0000808Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000809--------------------------------------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000810
Barry Warsaw06557452001-12-14 20:47:12 +0000811- Guido's tutorial introduction to the new type/class features has
812 been extensively updated. See
813
814 http://www.python.org/2.2/descrintro.html
815
816 That remains the primary documentation in this area.
817
Guido van Rossum33bab012001-12-05 22:45:48 +0000818- Fixed a leak: instance variables declared with __slots__ were never
819 deleted!
820
Guido van Rossum4b800852001-12-03 00:54:52 +0000821- The "delete attribute" method of descriptor objects is called
822 __delete__, not __del__. In previous releases, it was mistakenly
823 called __del__, which created an unfortunate overloading condition
824 with finalizers. (The "get attribute" and "set attribute" methods
825 are still called __get__ and __set__, respectively.)
826
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000827- Some subtle issues with the super built-in were fixed:
828
829 (a) When super itself is subclassed, its __get__ method would still
830 return an instance of the base class (i.e., of super).
831
832 (b) super(C, C()).__class__ would return C rather than super. This
833 is confusing. To fix this, I decided to change the semantics of
834 super so that it only applies to code attributes, not to data
835 attributes. After all, overriding data attributes is not
836 supported anyway.
837
838 (c) The __get__ method didn't check whether the argument was an
839 instance of the type used in creation of the super instance.
840
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000841- Previously, hash() of an instance of a subclass of a mutable type
842 (list or dictionary) would return some value, rather than raising
843 TypeError. This has been fixed. Also, directly calling
844 dict.__hash__ and list.__hash__ now raises the same TypeError
845 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000846
Guido van Rossumd331cb52001-12-05 19:46:42 +0000847- New-style objects now support deleting their __dict__. This is for
848 all intents and purposes equivalent to assigning a brand new empty
849 dictionary, but saves space if the object is not used further.
850
Tim Petersb3c9af12001-11-17 00:21:57 +0000851Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000852-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000853
Tim Peters3caca232001-12-06 06:23:26 +0000854- -Qnew now works as documented in PEP 238: when -Qnew is passed on
855 the command line, all occurrences of "/" use true division instead
856 of classic division. See the PEP for details. Note that "all"
857 means all instances in library and 3rd-party modules, as well as in
858 your own code. As the PEP says, -Qnew is intended for use only in
859 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000860 Note that test_coercion.py in the standard Python test suite fails
861 under -Qnew; this is expected, and won't be repaired until true
862 division becomes the default (in the meantime, test_coercion is
863 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000864
Fred Drake6c01e252001-12-14 17:08:12 +0000865- complex() now only allows the first argument to be a string
866 argument, and raises TypeError if either the second arg is a string
867 or if the second arg is specified when the first is a string.
868
Tim Petersb3c9af12001-11-17 00:21:57 +0000869Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000870-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000871
Martin v. Löwis560da622001-11-24 09:24:51 +0000872- gc.get_referents was renamed to gc.get_referrers.
873
Tim Petersb3c9af12001-11-17 00:21:57 +0000874Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000875-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000876
Tim Peters25059d32001-12-07 20:35:43 +0000877- Functions in the os.spawn() family now release the global interpreter
878 lock around calling the platform spawn. They should always have done
879 this, but did not before 2.2c1. Multithreaded programs calling
880 an os.spawn function with P_WAIT will no longer block all Python threads
881 until the spawned program completes. It's possible that some programs
882 relies on blocking, although more likely by accident than by design.
883
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000884- webbrowser defaults to netscape.exe on OS/2 now.
885
Martin v. Löwis652e1912001-11-25 14:50:56 +0000886- Tix.ResizeHandle exposes detach_widget, hide, and show.
887
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000888- The charset alias windows_1252 has been added.
889
Barry Warsaw06557452001-12-14 20:47:12 +0000890- types.StringTypes is a tuple containing the defined string types;
891 usually this will be (str, unicode), but if Python was compiled
892 without Unicode support it will be just (str,).
893
894- The pulldom and minidom modules were synchronized to PyXML.
895
Tim Petersb3c9af12001-11-17 00:21:57 +0000896Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000897-----------
Tim Petersb3c9af12001-11-17 00:21:57 +0000898
Barry Warsaw06557452001-12-14 20:47:12 +0000899- A new script called Tools/scripts/google.py was added, which fires
900 off a search on Google.
901
Tim Petersb3c9af12001-11-17 00:21:57 +0000902Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000903-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000904
Barry Warsaw06557452001-12-14 20:47:12 +0000905- Note that release builds of Python should arrange to define the
906 preprocessor symbol NDEBUG on the command line (or equivalent).
907 In the 2.2 pre-release series we tried to define this by magic in
908 Python.h instead, but it proved to cause problems for extension
909 authors. The Unix, Windows and Mac builds now all define NDEBUG in
910 release builds via cmdline (or equivalent) instead. Ports to
911 other platforms should do likewise.
912
Jack Jansen1999ef42001-12-06 21:47:20 +0000913- It is no longer necessary to use --with-suffix when building on a
914 case-insensitive file system (such as Mac OS X HFS+). In the build
915 directory an extension is used, but not in the installed python.
916
Tim Petersb3c9af12001-11-17 00:21:57 +0000917C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000918-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000919
Tim Petersf582b822001-12-11 18:51:08 +0000920- New function PyDict_MergeFromSeq2() exposes the builtin dict
921 constructor's logic for updating a dictionary from an iterable object
922 producing key-value pairs.
923
Tim Peterscffed4b2001-11-29 03:26:37 +0000924- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000925 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000926 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
927 dump core in some bad cases. This has been repaired. As a result,
928 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
929 previously went unchallenged.
930
Tim Petersb3c9af12001-11-17 00:21:57 +0000931New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000932-------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000933
934Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000935-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000936
937Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000938-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000939
940Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000941----
Tim Petersb3c9af12001-11-17 00:21:57 +0000942
Jack Jansenffa260f2001-12-06 21:14:00 +0000943- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
944 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000945
Barry Warsaw06557452001-12-14 20:47:12 +0000946- Changed logic for finding python home in Mac OS X framework Pythons.
947 Now sys.executable points to the executable again, in stead of to
948 the shared library. The latter is used only for locating the python
949 home.
950
951
Tim Peters84362bc2001-10-19 17:55:30 +0000952What's New in Python 2.2b2?
Tim Peters84362bc2001-10-19 17:55:30 +0000953===========================
954
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000955*Release date: 16-Nov-2001*
956
Tim Peters84362bc2001-10-19 17:55:30 +0000957Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000958--------------------------------------------
Tim Peters84362bc2001-10-19 17:55:30 +0000959
Guido van Rossum3d27df02001-11-15 20:27:54 +0000960- Multiple inheritance mixing new-style and classic classes in the
961 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000962
963 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000964 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000965
966 The MRO (method resolution order) for each base class is respected
967 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000968 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000969 This needs to be documented.
970
Tim Petersa427a2b2001-10-29 22:25:45 +0000971- The new builtin dictionary() constructor, and dictionary type, have
972 been renamed to dict. This reflects a decade of common usage.
973
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000974- dict() now accepts an iterable object producing 2-sequences. For
975 example, dict(d.items()) == d for any dictionary d. The argument,
976 and the elements of the argument, can be any iterable objects.
977
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000978- New-style classes can now have a __del__ method, which is called
979 when the instance is deleted (just like for classic classes).
980
Guido van Rossum12d955c2001-10-26 14:56:06 +0000981- Assignment to object.__dict__ is now possible, for objects that are
982 instances of new-style classes that have a __dict__ (unless the base
983 class forbids it).
984
Guido van Rossumc8e56452001-10-22 00:43:43 +0000985- Methods of built-in types now properly check for keyword arguments
986 (formerly these were silently ignored). The only built-in methods
987 that take keyword arguments are __call__, __init__ and __new__.
988
Guido van Rossum86443212001-10-27 22:28:54 +0000989- The socket function has been converted to a type; see below.
990
Tim Peters84362bc2001-10-19 17:55:30 +0000991Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000992-----------------
Tim Peters84362bc2001-10-19 17:55:30 +0000993
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000994- Assignment to __debug__ raises SyntaxError at compile-time. This
995 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000996 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000997
Guido van Rossum12d955c2001-10-26 14:56:06 +0000998- Clarified the error messages for unsupported operands to an operator
999 (like 1 + '').
1000
Tim Peters84362bc2001-10-19 17:55:30 +00001001Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001002-----------------
Tim Peters84362bc2001-10-19 17:55:30 +00001003
Tim Peters5ebfd362001-11-13 23:11:19 +00001004- mmap has a new keyword argument, "access", allowing a uniform way for
1005 both Windows and Unix users to create read-only, write-through and
1006 copy-on-write memory mappings. This was previously possible only on
1007 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001008 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +00001009 platforms. Thanks to Jay T Miller for repairing this!
1010
Tim Peters169ded02001-11-03 19:57:21 +00001011- By default, the gc.garbage list now contains only those instances in
1012 unreachable cycles that have __del__ methods; in 2.1 it contained all
1013 instances in unreachable cycles. "Instances" here has been generalized
1014 to include instances of both new-style and old-style classes.
1015
Guido van Rossum12d955c2001-10-26 14:56:06 +00001016- The socket module defines a new method for socket objects,
1017 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +00001018 send() until all data has been sent. Also, the socket function has
1019 been converted to a subclassable type, like list and tuple (etc.)
1020 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +00001021
1022- Various bugfixes to the curses module. There is now a test suite
1023 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001024
Guido van Rossum692adf12001-10-30 03:03:03 +00001025- binascii.b2a_base64 no longer places an arbitrary restriction of 57
1026 bytes on its input.
1027
Tim Peters84362bc2001-10-19 17:55:30 +00001028Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001029-------
Tim Peters84362bc2001-10-19 17:55:30 +00001030
Tim Peters5ebfd362001-11-13 23:11:19 +00001031- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +00001032 convenience function.
1033
Tim Peters75335872001-11-03 19:35:43 +00001034- Symbolic group names in regular expressions must be unique. For
1035 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
1036 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +00001037 Python 2.2 detects this error at regexp compilation time;
1038 previously, the error went undetected, and results were
1039 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
1040 pattern.subn() methods have been rewritten in C. Also, an
1041 experimental function/method finditer() has been added, which works
1042 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +00001043
Martin v. Löwisb7b32602001-11-02 23:48:20 +00001044- Tix exposes more commands through the classes DirSelectBox,
1045 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
1046 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
1047 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
1048
Tim Peters98791af2001-10-23 01:59:54 +00001049- Traceback objects are now scanned by cyclic garbage collection, so
1050 cycles created by casual use of sys.exc_info() no longer cause
1051 permanent memory leaks (provided garbage collection is enabled).
1052
Guido van Rossum49192142001-10-24 20:51:44 +00001053- os.extsep -- a new variable needed by the RISCOS support. It is the
1054 separator used by extensions, and is '.' on all platforms except
1055 RISCOS, where it is '/'. There is no need to use this variable
1056 unless you have a masochistic desire to port your code to RISCOS.
1057
Barry Warsaw012852b2001-11-16 16:17:27 +00001058- mimetypes.py has optional support for non-standard, but commonly
1059 found types. guess_type() and guess_extension() now accept an
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001060 optional 'strict' flag, defaulting to true, which controls whether
Barry Warsaw012852b2001-11-16 16:17:27 +00001061 recognize non-standard types or not. A few non-standard types we
1062 know about have been added. Also, when run as a script, there are
1063 new -l and -e options.
1064
1065- statcache is now deprecated.
1066
1067- email.Utils.formatdate() now produces the preferred RFC 2822 style
1068 dates with numeric timezones (it used to produce obsolete dates
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001069 hard coded to "GMT" timezone). An optional 'localtime' flag is
Barry Warsaw012852b2001-11-16 16:17:27 +00001070 added to produce dates in the local timezone, with daylight savings
1071 time properly taken into account.
1072
1073- In pickle and cPickle, instead of masking errors in load() by
1074 transforming them into SystemError, we let the original exception
1075 propagate out. Also, implement support for __safe_for_unpickling__
1076 in pickle, as it already was supported in cPickle.
1077
Tim Peters84362bc2001-10-19 17:55:30 +00001078Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001079-----------
Tim Peters84362bc2001-10-19 17:55:30 +00001080
1081Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001082-----
Tim Peters84362bc2001-10-19 17:55:30 +00001083
Barry Warsaw012852b2001-11-16 16:17:27 +00001084- The dbm module is built using libdb1 if available. The bsddb module
1085 is built with libdb3 if available.
1086
1087- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
1088
Tim Peters84362bc2001-10-19 17:55:30 +00001089C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001090-----
Tim Peters84362bc2001-10-19 17:55:30 +00001091
Tim Peters1fc240e2001-10-26 05:06:50 +00001092- New function PySequence_Fast_GET_SIZE() returns the size of a non-
1093 NULL result from PySequence_Fast(), more quickly than calling
1094 PySequence_Size().
1095
Barry Warsaw012852b2001-11-16 16:17:27 +00001096- New argument unpacking function PyArg_UnpackTuple() added.
1097
1098- New functions PyObject_CallFunctionObjArgs() and
1099 PyObject_CallMethodObjArgs() have been added to make it more
1100 convenient and efficient to call functions and methods from C.
1101
1102- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
1103 possible that this will propagate errors it didn't before.
1104
1105- New function PyObject_CheckReadBuffer(), which returns true if its
1106 argument supports the single-segment readable buffer interface.
1107
Tim Peters84362bc2001-10-19 17:55:30 +00001108New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001109-------------
Tim Peters84362bc2001-10-19 17:55:30 +00001110
Guido van Rossum86443212001-10-27 22:28:54 +00001111- We've finally confirmed that this release builds on HP-UX 11.00,
1112 *with* threads, and passes the test suite.
1113
Tim Peters7a33d8b2001-11-05 02:51:07 +00001114- Thanks to a series of patches from Michael Muller, Python may build
1115 again under OS/2 Visual Age C++.
1116
Guido van Rossum49192142001-10-24 20:51:44 +00001117- Updated RISCOS port by Dietmar Schwertberger.
1118
Tim Peters84362bc2001-10-19 17:55:30 +00001119Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001120-----
Tim Peters84362bc2001-10-19 17:55:30 +00001121
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001122- Added a test script for the curses module. It isn't run automatically;
1123 regrtest.py must be run with '-u curses' to enable it.
1124
Tim Peters84362bc2001-10-19 17:55:30 +00001125Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001126-------
Tim Peters84362bc2001-10-19 17:55:30 +00001127
Barry Warsaw012852b2001-11-16 16:17:27 +00001128Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001129----
Barry Warsaw012852b2001-11-16 16:17:27 +00001130
1131- PythonScript has been moved to unsupported and is slated to be
1132 removed completely in the next release.
1133
1134- It should now be possible to build applets that work on both OS9 and
1135 OSX.
1136
1137- The core is now linked with CoreServices not Carbon; as a side
1138 result, default 8bit encoding on OSX is now ASCII.
1139
1140- Python should now build on OSX 10.1.1
1141
Tim Peters84362bc2001-10-19 17:55:30 +00001142
Tim Petersabf925f2001-09-28 21:53:42 +00001143What's New in Python 2.2b1?
Tim Petersabf925f2001-09-28 21:53:42 +00001144===========================
1145
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001146*Release date: 19-Oct-2001*
1147
Tim Petersabf925f2001-09-28 21:53:42 +00001148Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001149--------------------------------------------
Tim Petersabf925f2001-09-28 21:53:42 +00001150
Guido van Rossum687ae002001-10-15 22:03:32 +00001151- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001152 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +00001153 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001154 remains: the __dict__ of a new-style class is a read-only proxy; you
1155 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +00001156 __defined__ attribute of new-style types no longer exists, for lack
1157 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001158 future a __cache__ may be resurrected with a similar function, if I
1159 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +00001160
Tim Peters1c9ca872001-10-04 06:43:12 +00001161- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
1162 always returned None, even when there was a class docstring).
1163
1164- doctest now finds and runs docstrings attached to new-style classes,
1165 class methods, static methods, and properties.
1166
Guido van Rossum9074ef62001-10-16 21:34:49 +00001167Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001168-----------------
Tim Petersabf925f2001-09-28 21:53:42 +00001169
Guido van Rossuma8bcf802001-10-15 15:53:58 +00001170- A very subtle syntactical pitfall in list comprehensions was fixed.
1171 For example: [a+b for a in 'abc', for b in 'def']. The comma in
1172 this example is a mistake. Previously, this would silently let 'a'
1173 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
1174 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
1175 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
1176 Note that [a for a in <singleton>] is a convoluted way to say
1177 [<singleton>] anyway, so it's not like any expressiveness is lost.
1178
Guido van Rossum9074ef62001-10-16 21:34:49 +00001179- getattr(obj, name, default) now only catches AttributeError, as
1180 documented, rather than returning the default value for all
1181 exceptions (which could mask bugs in a __getattr__ hook, for
1182 example).
1183
Fred Drakecb7a6b52001-10-22 18:41:51 +00001184- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +00001185 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001186 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +00001187 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +00001188
Guido van Rossum1c486092001-10-19 02:05:35 +00001189- unicode(obj) now behaves more like str(obj), accepting arbitrary
1190 objects, and calling a __unicode__ method if it exists.
1191 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +00001192 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +00001193
Barry Warsawf6fb1712001-10-19 05:35:40 +00001194- isinstance() now allows any object as the first argument and a
1195 class, a type or something with a __bases__ tuple attribute for the
1196 second argument. The second argument may also be a tuple of a
1197 class, type, or something with __bases__, in which case isinstance()
1198 will return true if the first argument is an instance of any of the
1199 things contained in the second argument tuple. E.g.
1200
1201 isinstance(x, (A, B))
1202
1203 returns true if x is an instance of A or B.
1204
Guido van Rossum9074ef62001-10-16 21:34:49 +00001205Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001206-----------------
Guido van Rossum9074ef62001-10-16 21:34:49 +00001207
1208- thread.start_new_thread() now returns the thread ID (previously None).
1209
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001210- binascii has now two quopri support functions, a2b_qp and b2a_qp.
1211
Guido van Rossumc524d952001-10-19 01:31:59 +00001212- readline now supports setting the startup_hook and the
1213 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +00001214
Guido van Rossumc524d952001-10-19 01:31:59 +00001215- os and posix supports chroot(), setgroups() and unsetenv() where
1216 available. The stat(), fstat(), statvfs() and fstatvfs() functions
1217 now return "pseudo-sequences" -- the various fields can now be
1218 accessed as attributes (e.g. os.stat("/").st_mtime) but for
1219 backwards compatibility they also behave as a fixed-length sequence.
1220 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +00001221 attributes.
1222
1223- time: localtime(), gmtime() and strptime() now return a
1224 pseudo-sequence similar to the os.stat() return value, with
1225 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +00001226
Guido van Rossum9074ef62001-10-16 21:34:49 +00001227- Decompression objects in the zlib module now accept an optional
1228 second parameter to decompress() that specifies the maximum amount
1229 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +00001230
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001231- optional SSL support in the socket module now exports OpenSSL
1232 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
1233 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +00001234 automatically seed its PRNG. Also, the keyfile and certfile
1235 arguments to socket.ssl() are now optional.
1236
1237- posixmodule (and by extension, the os module on POSIX platforms) now
1238 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001239
Guido van Rossum9074ef62001-10-16 21:34:49 +00001240Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001241-------
Guido van Rossum3c288632001-10-16 21:13:49 +00001242
Tim Peters7402f792001-10-02 03:53:41 +00001243- doctest now excludes functions and classes not defined by the module
1244 being tested, thanks to Tim Hochberg.
1245
Fred Drakecb7a6b52001-10-22 18:41:51 +00001246- HotShot, a new profiler implemented using a C-based callback, has
1247 been added. This substantially reduces the overhead of profiling,
1248 but it is still quite preliminary. Support modules and
1249 documentation will be added in upcoming releases (before 2.2 final).
1250
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001251- profile now produces correct output in situations where an exception
1252 raised in Python is cleared by C code (e.g. hasattr()). This used
1253 to cause wrong output, including spurious claims of recursive
1254 functions and attribution of time spent to the wrong function.
1255
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001256 The code and documentation for the derived OldProfile and HotProfile
1257 profiling classes was removed. The code hasn't worked for years (if
1258 you tried to use them, they raised exceptions). OldProfile
1259 intended to reproduce the behavior of the profiler Python used more
1260 than 7 years ago, and isn't interesting anymore. HotProfile intended
1261 to provide a faster profiler (but producing less information), and
1262 that's a worthy goal we intend to meet via a different approach (but
1263 without losing information).
1264
Tim Peterscce092d2001-10-09 05:31:56 +00001265- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001266 a much better system-specific calibration constant. The constant can
1267 now be specified in an instance constructor, or as a Profile class or
1268 instance variable, instead of by editing profile.py's source code.
1269 Calibration must still be done manually (see the docs for the profile
1270 module).
1271
1272 Note that Profile.calibrate() must be overriden by subclasses.
1273 Improving the accuracy required exploiting detailed knowledge of
1274 profiler internals; the earlier method abstracted away the details
1275 and measured a simplified model instead, but consequently computed
1276 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001277
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001278- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001279 which indicates whether output is intended for the header 'Q'
1280 encoding.
1281
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001282- The SocketServer.ThreadingMixIn class now closes the request after
1283 finish_request() returns. (Not when it errors out though.)
1284
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001285- The nntplib module's NNTP.body() method has grown a 'file' argument
Barry Warsawf6fb1712001-10-19 05:35:40 +00001286 to allow saving the message body to a file.
1287
1288- The email package has added a class email.Parser.HeaderParser which
1289 only parses headers and does not recurse into the message's body.
1290 Also, the module/class MIMEAudio has been added for representing
1291 audio data (contributed by Anthony Baxter).
1292
1293- ftplib should be able to handle files > 2GB.
1294
1295- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1296 ON, and OFF.
1297
Fred Drakecb7a6b52001-10-22 18:41:51 +00001298- xml.dom.minidom NodeList objects now support the length attribute
1299 and item() method as required by the DOM specifications.
1300
Guido van Rossumed554f62001-10-02 23:15:37 +00001301Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001302-----------
Guido van Rossumed554f62001-10-02 23:15:37 +00001303
1304- Demo/dns was removed. It no longer serves any purpose; a package
1305 derived from it is now maintained by Anthony Baxter, see
1306 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001307
Barry Warsawf6fb1712001-10-19 05:35:40 +00001308- The freeze tool has been made more robust, and two new options have
1309 been added: -X and -E.
1310
Tim Petersabf925f2001-09-28 21:53:42 +00001311Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001312-----
Tim Petersabf925f2001-09-28 21:53:42 +00001313
Barry Warsawf6fb1712001-10-19 05:35:40 +00001314- configure will use CXX in LINKCC if CXX is used to build main() and
1315 the system requires to link a C++ main using the C++ compiler.
1316
Tim Petersabf925f2001-09-28 21:53:42 +00001317C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001318-----
Tim Petersabf925f2001-09-28 21:53:42 +00001319
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001320- The documentation for the tp_compare slot is updated to require that
1321 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1322 not correct. This is not yet enforced but will be enforced in
1323 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1324 "NotImplemented". Right now, -1 should be used for an error return.
1325
Tim Petersd38b1c72001-09-30 05:09:37 +00001326- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1327 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1328 as long) arguments.
1329
Guido van Rossum3c288632001-10-16 21:13:49 +00001330- PyThread_start_new_thread() now returns a long int giving the thread
1331 ID, if one can be calculated; it returns -1 for error, 0 if no
1332 thread ID is calculated (this is an incompatible change, but only
1333 the thread module used this API). This code has only really been
1334 tested on Linux and Windows; other platforms please beware (and
1335 report any bugs or strange behavior).
1336
Guido van Rossum1c486092001-10-19 02:05:35 +00001337- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1338 input.
1339
Tim Petersabf925f2001-09-28 21:53:42 +00001340New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001341-------------
Tim Petersabf925f2001-09-28 21:53:42 +00001342
1343Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001344-----
Tim Petersabf925f2001-09-28 21:53:42 +00001345
1346Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001347-------
Tim Petersabf925f2001-09-28 21:53:42 +00001348
Tim Peters04cf1d32001-10-09 22:39:40 +00001349- Installer: If you install IDLE, and don't disable file-extension
1350 registration, a new "Edit with IDLE" context (right-click) menu entry
1351 is created for .py and .pyw files.
1352
Tim Peters1ce3cf72001-10-01 17:58:40 +00001353- The signal module now supports SIGBREAK on Windows, thanks to Steven
1354 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1355 action remains to call Win32 ExitProcess(). This can be changed via
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001356 signal.signal(). For example::
Tim Peters1ce3cf72001-10-01 17:58:40 +00001357
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001358 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1359 # (SIGINT) behavior.
1360 import signal
1361 signal.signal(signal.SIGBREAK, signal.default_int_handler)
Tim Peters1ce3cf72001-10-01 17:58:40 +00001362
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001363 try:
1364 while 1:
1365 pass
1366 except KeyboardInterrupt:
1367 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1368 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1369 # program without the possibility for any Python-level cleanup).
1370 print "Clean exit"
Tim Peters1ce3cf72001-10-01 17:58:40 +00001371
Tim Petersabf925f2001-09-28 21:53:42 +00001372
Tim Petersb07352e2001-09-08 01:25:47 +00001373What's New in Python 2.2a4?
1374===========================
1375
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001376*Release date: 28-Sep-2001*
1377
Guido van Rossum808eea72001-09-25 04:15:41 +00001378Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001379--------------------------------------------
Guido van Rossum808eea72001-09-25 04:15:41 +00001380
1381- pydoc and inspect are now aware of new-style classes;
1382 e.g. help(list) at the interactive prompt now shows proper
1383 documentation for all operations on list objects.
1384
1385- Applications using Jim Fulton's ExtensionClass module can now safely
1386 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1387 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1388 examples also work again. It is hoped that Gtk and Boost also work
1389 with 2.2a4 and beyond. (If you can confirm this, please write
1390 webmaster@python.org; if there are still problems, please open a bug
1391 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001392
Tim Peters66c1a522001-09-24 21:17:50 +00001393- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001394 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001395 in the constructed property object. fget, fset and fdel weren't
1396 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1397 associate a docstring with a property.
1398
Guido van Rossum808eea72001-09-25 04:15:41 +00001399- Comparison overloading is now more completely implemented. For
1400 example, a str subclass instance can properly be compared to a str
1401 instance, and it can properly overload comparison. Ditto for most
1402 other built-in object types.
1403
1404- The repr() of new-style classes has changed; instead of <type
1405 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1406 *except* for built-in types, which are still rendered as <type
1407 'Foo'> (to avoid upsetting existing code that might parse or
1408 otherwise rely on repr() of certain type objects).
1409
1410- The repr() of new-style objects is now always <Foo object at XXX>;
1411 previously, it was sometimes <Foo instance at XXX>.
1412
1413- For new-style classes, what was previously called __getattr__ is now
1414 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001415 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001416 one in classic classes is defined which is called only if regular
1417 attribute access raises AttributeError; to catch *all* attribute
1418 access, you can use __getattribute__ (for new-style classes). If
1419 both are defined, __getattribute__ is called first, and if it raises
1420 AttributeError, __getattr__ is called.
1421
1422- The __class__ attribute of new-style objects can be assigned to.
1423 The new class must have the same C-level object layout as the old
1424 class.
1425
1426- The builtin file type can be subclassed now. In the usual pattern,
1427 "file" is the name of the builtin type, and file() is a new builtin
1428 constructor, with the same signature as the builtin open() function.
1429 file() is now the preferred way to open a file.
1430
1431- Previously, __new__ would only see sequential arguments passed to
1432 the type in a constructor call; __init__ would see both sequential
1433 and keyword arguments. This made no sense whatsoever any more, so
1434 now both __new__ and __init__ see all arguments.
1435
1436- Previously, hash() applied to an instance of a subclass of str or
1437 unicode always returned 0. This has been repaired.
1438
1439- Previously, an operation on an instance of a subclass of an
1440 immutable type (int, long, float, complex, tuple, str, unicode),
1441 where the subtype didn't override the operation (and so the
1442 operation was handled by the builtin type), could return that
1443 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001444 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001445 with the same value as s.
1446
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001447- Provisional support for pickling new-style objects has been added.
1448
Guido van Rossum808eea72001-09-25 04:15:41 +00001449Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001450----
Guido van Rossum808eea72001-09-25 04:15:41 +00001451
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001452- file.writelines() now accepts any iterable object producing strings.
1453
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001454- PyUnicode_FromEncodedObject() now works very much like
1455 PyObject_Str(obj) in that it tries to use __str__/tp_str
1456 on the object if the object is not a string or buffer. This
1457 makes unicode() behave like str() when applied to non-string/buffer
1458 objects.
1459
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001460- PyFile_WriteObject now passes Unicode objects to the file's write
1461 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001462 of a print statement must support Unicode objects, i.e. they must
1463 at least convert them into ASCII strings.
1464
Guido van Rossum624c8af2001-09-18 15:21:04 +00001465- Thread scheduling on Solaris should be improved; it is no longer
1466 necessary to insert a small sleep at the start of a thread in order
1467 to let other runnable threads be scheduled.
1468
Tim Petersb07352e2001-09-08 01:25:47 +00001469Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001470-------
Tim Petersb07352e2001-09-08 01:25:47 +00001471
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001472- StringIO.StringIO instances and cStringIO.StringIO instances support
1473 read character buffer compatible objects for their .write() methods.
1474 These objects are converted to strings and then handled as such
1475 by the instances.
1476
Barry Warsaw2f600732001-09-24 04:28:10 +00001477- The "email" package has been added. This is basically a port of the
1478 mimelib package <http://sf.net/projects/mimelib> with API changes
1479 and some implementations updated to use iterators and generators.
1480
Tim Peters8a9c2842001-09-22 21:30:22 +00001481- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1482 restores the ability of Tools/scripts/ndiff.py to start producing output
1483 before the entire comparison is complete.
1484
Barry Warsaw58b072d2001-09-22 04:44:21 +00001485- StringIO.StringIO instances and cStringIO.StringIO instances support
1486 iteration just like file objects (i.e. their .readline() method is
1487 called for each iteration until it returns an empty string).
1488
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001489- The codecs module has grown four new helper APIs to access
1490 builtin codecs: getencoder(), getdecoder(), getreader(),
1491 getwriter().
1492
Guido van Rossum624c8af2001-09-18 15:21:04 +00001493- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1494 simplifies writing XML RPC servers.
1495
Barry Warsaw647d5e82001-09-28 17:01:02 +00001496- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001497 after interpretation of symbolic links. On non-Unix systems, this
1498 is an alias for os.path.abspath().
1499
Tim Peters16a77ad2001-09-08 04:00:12 +00001500- operator.indexOf() (PySequence_Index() in the C API) now works with any
1501 iterable object.
1502
Guido van Rossum624c8af2001-09-18 15:21:04 +00001503- smtplib now supports various authentication and security features of
1504 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001505
Guido van Rossum624c8af2001-09-18 15:21:04 +00001506- hmac: a new module implementing keyed hashing for message
1507 authentication.
1508
1509- mimetypes now recognizes more extensions and file types. At the
1510 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001511
Guido van Rossum624c8af2001-09-18 15:21:04 +00001512- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001513 Python 2.2 bytecode generation. It has also been promoted from a
1514 Tool to a standard library package. (Tools/compiler still exists as
1515 a sample driver.)
1516
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001517Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001518-----
Guido van Rossum624c8af2001-09-18 15:21:04 +00001519
Tim Petersb07352e2001-09-08 01:25:47 +00001520Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001521-----
Tim Petersb07352e2001-09-08 01:25:47 +00001522
Guido van Rossum624c8af2001-09-18 15:21:04 +00001523- Large file support (LFS) is now automatic when the platform supports
1524 it; no more manual configuration tweaks are needed. On Linux, at
1525 least, it's possible to have a system whose C library supports large
1526 files but whose kernel doesn't; in this case, large file support is
1527 still enabled but doesn't do you any good unless you upgrade your
1528 kernel or share your Python executable with another system whose
1529 kernel has large file support.
1530
1531- The configure script now supplies plausible defaults in a
1532 cross-compilation environment. This doesn't mean that the supplied
1533 values are always correct, or that cross-compilation now works
1534 flawlessly -- but it's a first step (and it shuts up most of
1535 autoconf's warnings about AC_TRY_RUN).
1536
1537- The Unix build is now a bit less chatty, courtesy of the parser
1538 generator. The build is completely silent (except for errors) when
1539 using "make -s", thanks to a -q option to setup.py.
1540
Tim Petersb07352e2001-09-08 01:25:47 +00001541C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001542-----
Tim Petersb07352e2001-09-08 01:25:47 +00001543
Guido van Rossum624c8af2001-09-18 15:21:04 +00001544- The "structmember" API now supports some new flag bits to deny read
1545 and/or write access to attributes in restricted execution mode.
1546
Tim Petersb07352e2001-09-08 01:25:47 +00001547New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001548-------------
Tim Petersb07352e2001-09-08 01:25:47 +00001549
Guido van Rossum624c8af2001-09-18 15:21:04 +00001550- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1551 (http://familiar.handhelds.org).
1552
Tim Petersb07352e2001-09-08 01:25:47 +00001553Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001554-----
Tim Petersb07352e2001-09-08 01:25:47 +00001555
Tim Peters8a9c2842001-09-22 21:30:22 +00001556- The "classic" standard tests, which work by comparing stdout to
1557 an expected-output file under Lib/test/output/, no longer stop at
1558 the first mismatch. Instead the test is run to completion, and a
1559 variant of ndiff-style comparison is used to report all differences.
1560 This is much easier to understand than the previous style of reporting.
1561
1562- The unittest-based standard tests now use regrtest's test_main()
1563 convention, instead of running as a side-effect of merely being
1564 imported. This allows these tests to be run in more natural and
1565 flexible ways as unittests, outside the regrtest framework.
1566
1567- regrtest.py is much better integrated with unittest and doctest now,
1568 especially in regard to reporting errors.
1569
Tim Petersb07352e2001-09-08 01:25:47 +00001570Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001571-------
Tim Petersb07352e2001-09-08 01:25:47 +00001572
Guido van Rossum624c8af2001-09-18 15:21:04 +00001573- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001574 that support it (NTFS under Windows 2000). See "What's New in
1575 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001576
Tim Petersb07352e2001-09-08 01:25:47 +00001577
Tim Petersedc99312001-08-22 21:36:50 +00001578What's New in Python 2.2a3?
1579===========================
1580
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001581*Release Date: 07-Sep-2001*
1582
Tim Petersedc99312001-08-22 21:36:50 +00001583Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001584----
Tim Petersedc99312001-08-22 21:36:50 +00001585
Tim Peters9fffa3e2001-09-04 05:14:19 +00001586- Conversion of long to float now raises OverflowError if the long is too
1587 big to represent as a C double.
1588
Tim Peters32f453e2001-09-03 08:35:41 +00001589- The 3-argument builtin pow() no longer allows a third non-None argument
1590 if either of the first two arguments is a float, or if both are of
1591 integer types and the second argument is negative (in which latter case
1592 the arguments are converted to float, so this is really the same
1593 restriction).
1594
Tim Peters5d2b77c2001-09-03 05:47:38 +00001595- The builtin dir() now returns more information, and sometimes much
1596 more, generally naming all attributes of an object, and all attributes
1597 reachable from the object via its class, and from its class's base
1598 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1599 an empty list. In 2.2a3,
1600
1601 >>> dir([])
1602 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1603 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1604 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1605 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1606 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1607 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1608 'reverse', 'sort']
1609
1610 dir(module) continues to return only the module's attributes, though.
1611
Tim Petersbdee63f2001-09-02 03:40:59 +00001612- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001613 than raising OverflowError. This is a partial implementation of PEP
1614 237. You can use -Wdefault::OverflowWarning to enable a warning for
1615 this situation, and -Werror::OverflowWarning to revert to the old
1616 OverflowError exception.
1617
Guido van Rossum61c345f2001-09-04 03:26:15 +00001618- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001619 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001620 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1621 -Qold, meaning the / operator has its classic meaning and no
1622 warnings are issued. Using -Qwarn issues a run-time warning about
1623 all uses of classic division for int and long arguments; -Qwarnall
1624 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001625 (for use with fixdiv.py).
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001626 [Note: the remainder of this item (preserved below) became
1627 obsolete in 2.2c1 -- -Qnew has global effect in 2.2] ::
1628
1629 Using -Qnew is questionable; it turns on new division by default, but
1630 only in the __main__ module. You can usefully combine -Qwarn or
1631 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1632 warns about classic division everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +00001633
Tim Petersbdee63f2001-09-02 03:40:59 +00001634- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001635 long, float, str, unicode, and tuple. (The types complex, list and
1636 dictionary can also be subclassed; this was introduced earlier.)
1637 Note that restrictions apply when subclassing immutable built-in
1638 types: you can only affect the value of the instance by overloading
1639 __new__. You can add mutable attributes, and the subclass instances
1640 will have a __dict__ attribute, but you cannot change the "value"
1641 (as implemented by the base class) of an immutable subclass instance
1642 once it is created.
1643
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001644- The dictionary constructor now takes an optional argument, a
1645 mapping-like object, and initializes the dictionary from its
1646 (key, value) pairs.
1647
Tim Petersbdee63f2001-09-02 03:40:59 +00001648- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001649 "cooperative super calls" in a multiple inheritance setting. For an
1650 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1651
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001652- A new built-in type, property, has been added. This enables the
1653 creation of "properties". These are attributes implemented by
1654 getter and setter functions (or only one of these for read-only or
1655 write-only attributes), without the need to override __getattr__.
1656 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001657
Tim Petersbdee63f2001-09-02 03:40:59 +00001658- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001659 liberalized, to allow leading zeroes. Examples of literals now
1660 legal that were SyntaxErrors before:
1661
1662 00.0 0e3 0100j 07.5 00000000000000000008.
1663
Tim Petersbdee63f2001-09-02 03:40:59 +00001664- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001665 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1666
Tim Petersedc99312001-08-22 21:36:50 +00001667Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001668-------
Tim Petersedc99312001-08-22 21:36:50 +00001669
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001670- telnetlib includes symbolic names for the options, and support for
1671 setting an option negotiation callback.
1672
Tim Petersa40c7932001-09-05 22:36:56 +00001673- The new C standard no longer requires that math libraries set errno to
1674 ERANGE on overflow. For platform libraries that exploit this new
1675 freedom, Python's overflow-checking was wholly broken. A new overflow-
1676 checking scheme attempts to repair that, but may not be reliable on all
1677 platforms (C doesn't seem to provide anything both useful and portable
1678 in this area anymore).
1679
Martin v. Löwis44f86962001-09-05 13:44:54 +00001680- Asynchronous timeout actions are available through the new class
1681 threading.Timer.
1682
Tim Peters78526162001-09-05 00:53:45 +00001683- math.log and math.log10 now return sensible results for even huge
1684 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1685
Tim Petersbdee63f2001-09-02 03:40:59 +00001686- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001687 currently held. See the docs for the imp module.
1688
Tim Petersbdee63f2001-09-02 03:40:59 +00001689- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001690 dumps containing ints written on platforms where Python ints are 8 bytes.
1691 When read on a box where Python ints are 4 bytes, such values are
1692 converted to Python longs.
1693
Tim Petersbdee63f2001-09-02 03:40:59 +00001694- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001695 code objects is no longer allowed. This plugs a security hole.
1696
Steve Purcell6091cd62001-09-06 16:05:17 +00001697- unittest.TestResult instances no longer store references to tracebacks
1698 generated by test failures. This prevents unexpected dangling references
1699 to objects that should be garbage collected between tests.
1700
Tim Petersedc99312001-08-22 21:36:50 +00001701Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001702-----
Tim Petersedc99312001-08-22 21:36:50 +00001703
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001704- Tools/scripts/fixdiv.py has been added which can be used to fix
1705 division operators as per PEP 238.
1706
Tim Petersedc99312001-08-22 21:36:50 +00001707Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001708-----
Tim Petersedc99312001-08-22 21:36:50 +00001709
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001710- If you are an adventurous person using Mac OS X you may want to look at
1711 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1712 application, which can be used for experimenting with Carbon or Cocoa.
1713 Discussion of this on pythonmac-sig, please.
1714
Tim Peters7eea37e2001-09-04 22:08:56 +00001715C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001716-----
Tim Peters7eea37e2001-09-04 22:08:56 +00001717
1718- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001719
Tim Peters9fffa3e2001-09-04 05:14:19 +00001720- Note that PyLong_AsDouble can fail! This has always been true, but no
1721 callers checked for it. It's more likely to fail now, because overflow
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001722 errors are properly detected now. The proper way to check::
Tim Peters9fffa3e2001-09-04 05:14:19 +00001723
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001724 double x = PyLong_AsDouble(some_long_object);
1725 if (x == -1.0 && PyErr_Occurred()) {
1726 /* The conversion failed. */
1727 }
Tim Peters9fffa3e2001-09-04 05:14:19 +00001728
Tim Petersbdee63f2001-09-02 03:40:59 +00001729- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001730 compile but will not participate in GC. To upgrade an extension
1731 module:
1732
1733 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001734
Neil Schemenauer4042c692001-08-30 15:38:01 +00001735 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1736 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001737
Neil Schemenauer4042c692001-08-30 15:38:01 +00001738 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1739 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001740
Neil Schemenauer4042c692001-08-30 15:38:01 +00001741 - remove PyGC_HEAD_SIZE from object size calculations
1742
1743 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1744
Tim Petersbdee63f2001-09-02 03:40:59 +00001745- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001746 These can be used safely to construct string objects from a
1747 sprintf-style format string (similar to the format string supported
1748 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001749
Tim Petersedc99312001-08-22 21:36:50 +00001750New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001751-------------
Tim Petersedc99312001-08-22 21:36:50 +00001752
Tim Petersb7da0902001-09-02 23:01:43 +00001753- Stephen Hansen contributed patches sufficient to get a clean compile
1754 under Borland C (Windows), but he reports problems running it and ran
1755 out of time to complete the port. Volunteers? Expect a MemoryError
1756 when importing the types module; this is probably shallow, and
1757 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001758
Tim Petersedc99312001-08-22 21:36:50 +00001759Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001760-----
Tim Petersedc99312001-08-22 21:36:50 +00001761
1762Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001763-------
Tim Petersedc99312001-08-22 21:36:50 +00001764
Tim Peters6e13a562001-09-06 00:32:15 +00001765- Large file support is now enabled on Win32 platforms as well as on
1766 Win64. This means that, for example, you can use f.tell() and f.seek()
1767 to manipulate files larger than 2 gigabytes (provided you have enough
1768 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001769 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1770 filesize limit, and large file support makes no difference there.
1771 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1772 NTFS has no practical limit on file size, and files of any size can be
1773 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001774
Tim Petersbdee63f2001-09-02 03:40:59 +00001775- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001776 points to command.com (patch from Brian Quinlan).
1777
Tim Petersedc99312001-08-22 21:36:50 +00001778
Tim Peters20f51a72001-07-21 02:31:40 +00001779What's New in Python 2.2a2?
1780===========================
1781
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001782*Release Date: 22-Aug-2001*
1783
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001784Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001785-----
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001786
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001787- Tim Peters developed a brand new Windows installer using Wise 8.1,
1788 generously donated to us by Wise Solutions.
1789
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001790- configure supports a new option --enable-unicode, with the values
1791 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1792 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001793
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001794- A new configure option --enable-framework builds a Mac OS X framework,
1795 which "make frameworkinstall" will install. This provides a starting
1796 point for more mac-like functionality, join pythonmac-sig@python.org
1797 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001798
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001799- The NeXT platform is no longer supported.
1800
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001801- The 'new' module is now statically linked.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001802
Tim Peters0afb6092001-08-15 06:06:44 +00001803Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001804-----
Tim Peters0afb6092001-08-15 06:06:44 +00001805
1806- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001807 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001808 the module docstring for details.
1809
Tim Peters20f51a72001-07-21 02:31:40 +00001810Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001811-----
Tim Peters20f51a72001-07-21 02:31:40 +00001812
Tim Peters5e824c32001-08-12 22:25:01 +00001813- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001814 platforms, allowing to give clearer test result output. regrtest
1815 also has optional --use/-u switch to run normally disabled tests
1816 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001817
Tim Peters20f51a72001-07-21 02:31:40 +00001818- Several new tests in the standard test suite, with special thanks to
1819 Nick Mathewson.
1820
1821Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001822----
Tim Peters20f51a72001-07-21 02:31:40 +00001823
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001824- The floor division operator // has been added as outlined in PEP
1825 238. The / operator still provides classic division (and will until
1826 Python 3.0) unless "from __future__ import division" is included, in
1827 which case the / operator will provide true division. The operator
1828 module provides truediv() and floordiv() functions. Augmented
1829 assignment variants are included, as are the equivalent overloadable
1830 methods and C API methods. See the PEP for a full discussion:
1831 <http://python.sf.net/peps/pep-0238.html>
1832
Tim Peters6cd6a822001-08-17 22:11:27 +00001833- Future statements are now effective in simulated interactive shells
1834 (like IDLE). This should "just work" by magic, but read Michael
1835 Hudson's "Future statements in simulated shells" PEP 264 for full
1836 details: <http://python.sf.net/peps/pep-0264.html>.
1837
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001838- The type/class unification (PEP 252-253) was integrated into the
1839 trunk and is not so tentative any more (the exact specification of
1840 some features is still tentative). A lot of work has done on fixing
1841 bugs and adding robustness and features (performance still has to
1842 come a long way).
1843
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001844- Warnings about a mismatch in the Python API during extension import
1845 now use the Python warning framework (which makes it possible to
1846 write filters for these warnings).
1847
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001848- A function's __dict__ (aka func_dict) will now always be a
1849 dictionary. It used to be possible to delete it or set it to None,
1850 but now both actions raise TypeErrors. It is still legal to set it
1851 to a dictionary object. Getting func.__dict__ before any attributes
1852 have been assigned now returns an empty dictionary instead of None.
1853
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001854- A new command line option, -E, was added which disables the use of
1855 all environment variables, or at least those that are specifically
1856 significant to Python. Usually those have a name starting with
1857 "PYTHON". This was used to fix a problem where the tests fail if
1858 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1859 older distribution.
1860
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001861Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001862-------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001863
Tim Peters5e824c32001-08-12 22:25:01 +00001864- New class Differ and new functions ndiff() and restore() in difflib.py.
1865 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001866 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001867
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001868- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1869 value using the minimal quoting required for the value; more
1870 reliable than using xml.sax.saxutils.escape() for attribute values.
1871
1872- Readline completion support for cmd.Cmd was added.
1873
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001874- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1875
1876- Added function threading.BoundedSemaphore()
1877
1878- Added Ka-Ping Yee's cgitb.py module.
1879
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001880- The 'new' module now exposes the CO_xxx flags.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001881
Martin v. Löwis560da622001-11-24 09:24:51 +00001882- The gc module offers the get_referents function.
1883
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001884New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001885-------------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001886
1887C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001888-----
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001889
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001890- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1891 which provide a cross-platform implementations for the
1892 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1893 the standard sprintf() and vsprintf() C lib APIs, these versions
1894 apply bounds checking on the used buffer which enhances protection
1895 against buffer overruns.
1896
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001897- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001898 and extensions using different Unicode widths is rendered next to
1899 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001900 will result in an ImportError. Unicode extensions writers must make
1901 sure to check the Unicode width compatibility in their extensions by
1902 using at least one of the mangled Unicode APIs in the extension.
1903
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001904- Two new flags METH_NOARGS and METH_O are available in method definition
1905 tables to simplify implementation of methods with no arguments and a
1906 single untyped argument. Calling such methods is more efficient than
1907 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1908 deprecated.
1909
Tim Petersc1731372001-08-04 08:12:36 +00001910Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001911-------
Tim Petersc1731372001-08-04 08:12:36 +00001912
1913- "import module" now compiles module.pyw if it exists and nothing else
1914 relevant is found.
1915
Tim Peters20f51a72001-07-21 02:31:40 +00001916
Guido van Rossum55a78992001-07-17 17:22:32 +00001917What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +00001918===========================
1919
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001920*Release date: 18-Jul-2001*
1921
Tim Petersf553f892001-05-01 20:45:31 +00001922Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001923----
Tim Petersa814db52001-05-14 07:05:58 +00001924
Tim Peters6d6c1a32001-08-02 04:15:00 +00001925- TENTATIVELY, a large amount of code implementing much of what's
1926 described in PEP 252 (Making Types Look More Like Classes) and PEP
1927 253 (Subtyping Built-in Types) was added. This will be released
1928 with Python 2.2a1. Documentation will be provided separately
1929 through http://www.python.org/2.2/. The purpose of releasing this
1930 with Python 2.2a1 is to test backwards compatibility. It is
1931 possible, though not likely, that a decision is made not to release
1932 this code as part of 2.2 final, if any serious backwards
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00001933 incompatibilities are found during alpha testing that cannot be
Tim Peters6d6c1a32001-08-02 04:15:00 +00001934 repaired.
1935
Guido van Rossum55a78992001-07-17 17:22:32 +00001936- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001937 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001938 more 'yield' statements. See PEP 255. Since this adds a new
1939 keyword to the language, this feature must be enabled by including a
1940 future statement: "from __future__ import generators" (see PEP 236).
1941 Generators will become a standard feature in a future release
1942 (probably 2.3). Without this future statement, 'yield' remains an
1943 ordinary identifier, but a warning is issued each time it is used.
1944 (These warnings currently don't conform to the warnings framework of
1945 PEP 230; we intend to fix this in 2.2a2.)
1946
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001947- The UTF-16 codec was modified to be more RFC compliant. It will now
1948 only remove BOM characters at the start of the string and then
1949 only if running in native mode (UTF-16-LE and -BE won't remove a
1950 leading BMO character).
1951
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001952- Strings now have a new method .decode() to complement the already
1953 existing .encode() method. These two methods provide direct access
1954 to the corresponding decoders and encoders of the registered codecs.
1955
1956 To enhance the usability of the .encode() method, the special
1957 casing of Unicode object return values was dropped (Unicode objects
1958 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001959
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001960 Both methods will now return whatever the codec in charge of the
1961 requested encoding returns as object, e.g. Unicode codecs will
1962 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1963 will return u"äöü"). This enables codec writer to create codecs
1964 for various simple to use conversions.
1965
1966 New codecs were added to demonstrate these new features (the .encode()
1967 and .decode() columns indicate the type of the returned objects):
1968
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001969 +---------+-----------+-----------+-----------------------------+
1970 |Name | .encode() | .decode() | Description |
1971 +=========+===========+===========+=============================+
1972 |uu | string | string | UU codec (e.g. for email) |
1973 +---------+-----------+-----------+-----------------------------+
1974 |base64 | string | string | base64 codec |
1975 +---------+-----------+-----------+-----------------------------+
1976 |quopri | string | string | quoted-printable codec |
1977 +---------+-----------+-----------+-----------------------------+
1978 |zlib | string | string | zlib compression |
1979 +---------+-----------+-----------+-----------------------------+
1980 |hex | string | string | 2-byte hex codec |
1981 +---------+-----------+-----------+-----------------------------+
1982 |rot-13 | string | Unicode | ROT-13 Unicode charmap codec|
1983 +---------+-----------+-----------+-----------------------------+
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001984
Mark Hammond2a0af792001-05-14 03:09:36 +00001985- Some operating systems now support the concept of a default Unicode
1986 encoding for file system operations. Notably, Windows supports 'mbcs'
1987 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001988 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001989 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001990
1991 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001992 functions that return filenames (such as os.listdir()) to return Python
1993 string objects pre-encoded using the default file system encoding for
1994 the platform. As this encoding is likely to be different from Python's
1995 default encoding, converting this name to a Unicode object before passing
1996 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001997 would attempt to use its default encoding (generally ASCII) rather than
1998 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001999
Tim Petersa814db52001-05-14 07:05:58 +00002000 In general, this change simply removes surprises when working with
2001 Unicode and the file system, making these operations work as you expect,
2002 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00002003 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00002004
Tim Peters61dff2b2001-05-08 15:43:37 +00002005- Float (and complex) literals in source code were evaluated to full
2006 precision only when running from a .py file; the same code loaded from a
2007 .pyc (or .pyo) file could suffer numeric differences starting at about the
2008 12th significant decimal digit. For example, on a machine with IEEE-754
2009 floating arithmetic,
2010
2011 x = 9007199254740992.0
2012 print long(x)
2013
2014 printed 9007199254740992 if run directly from .py, but 9007199254740000
2015 if from a compiled (.pyc or .pyo) file. This was due to marshal using
2016 str(float) instead of repr(float) when building code objects. marshal
2017 now uses repr(float) instead, which should reproduce floats to full
2018 machine precision (assuming the platform C float<->string I/O conversion
2019 functions are of good quality).
2020
2021 This may cause floating-point results to change in some cases, and
2022 usually for the better, but may also cause numerically unstable
2023 algorithms to break.
2024
Tim Peters2f228e72001-05-13 00:19:31 +00002025- The implementation of dicts suffers fewer collisions, which has speed
2026 benefits. However, the order in which dict entries appear in dict.keys(),
2027 dict.values() and dict.items() may differ from previous releases for a
2028 given dict. Nothing is defined about this order, so no program should
2029 rely on it. Nevertheless, it's easy to write test cases that rely on the
2030 order by accident, typically because of printing the str() or repr() of a
2031 dict to an "expected results" file. See Lib/test/test_support.py's new
2032 sortdict(dict) function for a simple way to display a dict in sorted
2033 order.
2034
Tim Peters7a3bfc32001-06-12 01:22:22 +00002035- Many other small changes to dicts were made, resulting in faster
2036 operation along the most common code paths.
2037
Guido van Rossum10315822001-05-01 20:54:30 +00002038- Dictionary objects now support the "in" operator: "x in dict" means
2039 the same as dict.has_key(x).
2040
Barry Warsaw51acc8d2001-06-26 20:12:50 +00002041- The update() method of dictionaries now accepts generic mapping
2042 objects. Specifically the argument object must support the .keys()
2043 and __getitem__() methods. This allows you to say, for example,
2044 {}.update(UserDict())
2045
Guido van Rossum10315822001-05-01 20:54:30 +00002046- Iterators were added; this is a generalized way of providing values
2047 to a for loop. See PEP 234. There's a new built-in function iter()
2048 to return an iterator. There's a new protocol to get the next value
2049 from an iterator using the next() method (in Python) or the
2050 tp_iternext slot (in C). There's a new protocol to get iterators
2051 using the __iter__() method (in Python) or the tp_iter slot (in C).
2052 Iterating (i.e. a for loop) over a dictionary generates its keys.
2053 Iterating over a file generates its lines.
2054
Tim Petersf553f892001-05-01 20:45:31 +00002055- The following functions were generalized to work nicely with iterator
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00002056 arguments::
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002057
Tim Peterse63415e2001-05-08 04:38:29 +00002058 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00002059 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
2060 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00002061 join() method of strings
2062 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00002063 'x in y' and 'x not in y' (PySequence_Contains() in C API)
2064 operator.countOf() (PySequence_Count() in C API)
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002065 right-hand side of assignment statements with multiple targets, such as ::
Tim Petersd6d010b2001-06-21 02:49:55 +00002066 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00002067
Tim Petersd85e1022001-05-11 21:51:48 +00002068- Accessing module attributes is significantly faster (for example,
2069 random.random or os.path or yourPythonModule.yourAttribute).
2070
Tim Peterse63415e2001-05-08 04:38:29 +00002071- Comparing dictionary objects via == and != is faster, and now works even
2072 if the keys and values don't support comparisons other than ==.
2073
Tim Peters95bf9392001-05-10 08:32:44 +00002074- Comparing dictionaries in ways other than == and != is slower: there were
2075 insecurities in the dict comparison implementation that could cause Python
2076 to crash if the element comparison routines for the dict keys and/or
2077 values mutated the dicts. Making the code bulletproof slowed it down.
2078
Tim Peterseb28ef22001-06-02 05:27:19 +00002079- Collisions in dicts are resolved via a new approach, which can help
2080 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00002081 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00002082 faster now. Thanks to Christian Tismer for pointing out the cause and
2083 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00002084
Tim Peters52e155e2001-06-16 05:42:57 +00002085- repr() is much faster for large containers (dict, list, tuple).
2086
2087
Tim Petersa814db52001-05-14 07:05:58 +00002088Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002089-------
Tim Petersa814db52001-05-14 07:05:58 +00002090
Fred Drake960fdf92001-07-20 18:38:26 +00002091- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002092 were added to the string module. These a locale-independent
Fred Drake960fdf92001-07-20 18:38:26 +00002093 constants, unlike letters, lowercase, and uppercase. These are now
2094 use in appropriate locations in the standard library.
2095
Martin v. Löwisf0473d52001-07-18 16:17:16 +00002096- The flags used in dlopen calls can now be configured using
2097 sys.setdlopenflags and queried using sys.getdlopenflags.
2098
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00002099- Fredrik Lundh's xmlrpclib is now a standard library module. This
2100 provides full client-side XML-RPC support. In addition,
2101 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
2102 one asyncore-based). Thanks to Eric Raymond for the documentation.
2103
Guido van Rossum643d3912001-07-05 14:46:25 +00002104- The xrange() object is simplified: it no longer supports slicing,
2105 repetition, comparisons, efficient 'in' checking, the tolist()
2106 method, or the start, stop and step attributes. See PEP 260.
2107
Martin v. Löwisebf94db2001-06-06 06:25:40 +00002108- A new function fnmatch.filter to filter lists of file names was added.
2109
Barry Warsawffd674d2001-05-22 16:00:10 +00002110- calendar.py uses month and day names based on the current locale.
2111
Guido van Rossum2e0a6542001-05-15 02:14:44 +00002112- strop is now *really* obsolete (this was announced before with 1.6),
2113 and issues DeprecationWarning when used (except for the four items
2114 that are still imported into string.py).
2115
Tim Petersa814db52001-05-14 07:05:58 +00002116- Cookie.py now sorts key+value pairs by key in output strings.
2117
2118- pprint.isrecursive(object) didn't correctly identify recursive objects.
2119 Now it does.
2120
Tim Peters95b3f782001-05-14 18:39:41 +00002121- pprint functions now much faster for large containers (tuple, list, dict).
2122
Tim Peters7b9542a2001-06-10 23:40:19 +00002123- New 'q' and 'Q' format codes in the struct module, corresponding to C
2124 types "long long" and "unsigned long long" (on Windows, __int64). In
2125 native mode, these can be used only when the platform C compiler supports
2126 these types (when HAVE_LONG_LONG is #define'd by the Python config
2127 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00002128 In standard mode, 'q' and 'Q' are supported on all platforms, and are
2129 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00002130
Guido van Rossum83213cc2001-06-12 16:48:52 +00002131- The site module installs a new built-in function 'help' that invokes
2132 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
2133 it displays a message reminding the user to use 'help()' or
2134 'help(object)'.
2135
Tim Petersa814db52001-05-14 07:05:58 +00002136Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002137-----
Tim Petersa814db52001-05-14 07:05:58 +00002138
2139- New test_mutants.py runs dict comparisons where the key and value
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002140 comparison operators mutate the dicts randomly during comparison. This
Tim Petersa814db52001-05-14 07:05:58 +00002141 rapidly causes Python to crash under earlier releases (not for the faint
2142 of heart: it can also cause Win9x to freeze or reboot!).
2143
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002144- New test_pprint.py verifies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00002145 pprint.isreadable() return sensible results. Also verifies that simple
2146 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00002147
Tim Peters4324aa32001-05-28 22:30:08 +00002148C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002149-----
Tim Peters4324aa32001-05-28 22:30:08 +00002150
2151- Removed the unused last_is_sticky argument from the internal
2152 _PyTuple_Resize(). If this affects you, you were cheating.
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002153
2154----
2155
2156**(For information about older versions, consult the HISTORY file.)**