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Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001+++++++++++
2Python News
3+++++++++++
4
Skip Montanaro4a385832002-09-20 17:08:52 +00005(editors: check NEWS.help for information about editing NEWS using ReST.)
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Tim Petersaf8446f2001-12-21 21:36:50 +00007What's New in Python 2.3 alpha 1?
Tim Petersaf8446f2001-12-21 21:36:50 +00008=================================
9
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +000010*XXX Release date: DD-MMM-2002 XXX*
11
Tim Petersaf8446f2001-12-21 21:36:50 +000012Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +000013--------------------------------------------
Tim Petersaf8446f2001-12-21 21:36:50 +000014
Guido van Rossume3438782002-08-12 03:42:03 +000015- Assignment to __class__ is disallowed if either the old and the new
16 class is a statically allocated type object (such as defined by an
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +000017 extension module). This prevents anomalies like 2.__class__ = bool.
Guido van Rossume3438782002-08-12 03:42:03 +000018
19- New-style object creation and deallocation have been sped up
20 significantly; they are now faster than classic instance creation
21 and deallocation.
22
23- The __slots__ variable can now mention "private" names, and the
24 right thing will happen (e.g. __slots__ = ["__foo"]).
25
26- The built-ins slice() and buffer() are now callable types. The
27 types classobj (formerly class), code, function, instance, and
28 instancemethod (formerly instance-method), which have no built-in
29 names but are accessible through the types module, are now also
30 callable. The type dict-proxy is renamed to dictproxy.
31
32- Cycles going through the __class__ link of a new-style instance are
33 now detected by the garbage collector.
34
35- Classes using __slots__ are now properly garbage collected.
36 [SF bug 519621]
37
38- Tightened the __slots__ rules: a slot name must be a valid Python
39 identifier.
40
41- The constructor for the module type now requires a name argument and
42 takes an optional docstring argument. Previously, this constructor
43 ignored its arguments. As a consequence, deriving a class from a
44 module (not from the module type) is now illegal; previously this
45 created an unnamed module, just like invoking the module type did.
46 [SF bug 563060]
47
48- A new type object, 'basestring', is added. This is a common base type
49 for 'str' and 'unicode', and can be used instead of
50 types.StringTypes, e.g. to test whether something is "a string":
51 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
52 is an abstract base class and cannot be instantiated directly.
53
54- Changed new-style class instantiation so that when C's __new__
55 method returns something that's not a C instance, its __init__ is
56 not called. [SF bug #537450]
57
58- Fixed super() to work correctly with class methods. [SF bug #535444]
59
60- If you try to pickle an instance of a class that has __slots__ but
61 doesn't define or override __getstate__, a TypeError is now raised.
62 This is done by adding a bozo __getstate__ to the class that always
63 raises TypeError. (Before, this would appear to be pickled, but the
64 state of the slots would be lost.)
65
Tim Petersaf8446f2001-12-21 21:36:50 +000066Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +000067-----------------
Tim Petersaf8446f2001-12-21 21:36:50 +000068
Martin v. Löwisa844f2d2002-10-05 09:46:48 +000069- Unicode file name processing for Windows (PEP 277) is implemented.
Mark Hammond8696ebc2002-10-08 02:44:31 +000070 All platforms now have an os.path.supports_unicode_filenames attribute,
71 which is set to True on Windows NT/2000/XP, and False elsewhere.
Martin v. Löwisa844f2d2002-10-05 09:46:48 +000072
Walter Dörwald3aeb6322002-09-02 13:14:32 +000073- Codec error handling callbacks (PEP 293) are implemented.
74 Error handling in unicode.encode or str.decode can now be customized.
75
Guido van Rossum45ec02a2002-08-19 21:43:18 +000076- A subtle change to the semantics of the built-in function intern():
77 interned strings are no longer immortal. You must keep a reference
78 to the return value intern() around to get the benefit.
79
Guido van Rossumf808b892002-08-16 03:38:10 +000080- Use of 'None' as a variable, argument or attribute name now
81 issues a SyntaxWarning. In the future, None may become a keyword.
82
Michael W. Hudsondd32a912002-08-15 14:59:02 +000083- SET_LINENO is gone. co_lnotab is now consulted to determine when to
84 call the trace function. C code that accessed f_lineno should call
85 PyCode_Addr2Line instead (f_lineno is still there, but not kept up
86 to date).
87
Guido van Rossum9be89462002-08-14 16:11:30 +000088- There's a new warning category, FutureWarning. This is used to warn
89 about a number of situations where the value or sign of an integer
90 result will change in Python 2.4 as a result of PEP 237 (integer
91 unification). The warnings implement stage B0 mentioned in that
92 PEP. The warnings are about the following situations:
93
94 - Octal and hex literals without 'L' prefix in the inclusive range
95 [0x80000000..0xffffffff]; these are currently negative ints, but
96 in Python 2.4 they will be positive longs with the same bit
97 pattern.
98
99 - Left shifts on integer values that cause the outcome to lose
100 bits or have a different sign than the left operand. To be
101 precise: x<<n where this currently doesn't yield the same value
102 as long(x)<<n; in Python 2.4, the outcome will be long(x)<<n.
103
104 - Conversions from ints to string that show negative values as
105 unsigned ints in the inclusive range [0x80000000..0xffffffff];
106 this affects the functions hex() and oct(), and the string
107 formatting codes %u, %o, %x, and %X. In Python 2.4, these will
108 show signed values (e.g. hex(-1) currently returns "0xffffffff";
109 in Python 2.4 it will return "-0x1").
110
Skip Montanaro979c74b2002-09-03 21:25:14 +0000111 - The bits manipulated under the cover by sys.setcheckinterval() have
112 been changed. Both the check interval and the ticker used to be
113 per-thread values. They are now just a pair of global variables. In
114 addition, the default check interval was boosted from 10 to 100
Neal Norwitz7165af22002-09-05 21:42:24 +0000115 bytecode instructions. This may have some effect on systems that
116 relied on the old default value. In particular, in multi-threaded
117 applications which try to be highly responsive, response time will
118 increase by some (perhaps imperceptible) amount.
Skip Montanaro979c74b2002-09-03 21:25:14 +0000119
Tim Petersd64c1de2002-08-12 17:36:03 +0000120- When multiplying very large integers, a version of the so-called
121 Karatsuba algorithm is now used. This is most effective if the
122 inputs have roughly the same size. If they both have about N digits,
123 Karatsuba multiplication has O(N**1.58) runtime (the exponent is
124 log_base_2(3)) instead of the previous O(N**2). Measured results may
Tim Peters012c0a32002-08-16 03:40:07 +0000125 be better or worse than that, depending on platform quirks. Besides
126 the O() improvement in raw instruction count, the Karatsuba algorithm
127 appears to have much better cache behavior on extremely large integers
128 (starting in the ballpark of a million bits). Note that this is a
129 simple implementation, and there's no intent here to compete with,
130 e.g., GMP. It gives a very nice speedup when it applies, but a package
131 devoted to fast large-integer arithmetic should run circles around it.
Tim Peters5af4e6c2002-08-12 02:31:19 +0000132
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000133- u'%c' will now raise a ValueError in case the argument is an
134 integer outside the valid range of Unicode code point ordinals.
135
Guido van Rossumdeb09362002-08-09 17:16:30 +0000136- The tempfile module has been overhauled for enhanced security. The
137 mktemp() function is now deprecated; new, safe replacements are
138 mkstemp() (for files) and mkdtemp() (for directories), and the
139 higher-level functions NamedTemporaryFile() and TemporaryFile().
140 Use of some global variables in this module is also deprecated; the
141 new functions have keyword arguments to provide the same
142 functionality. All Lib, Tools and Demo modules that used the unsafe
143 interfaces have been updated to use the safe replacements. Thanks
144 to Zack Weinberg!
145
Guido van Rossumd81a9832002-08-09 15:57:34 +0000146- When x is an object whose class implements __mul__ and __rmul__,
147 1.0*x would correctly invoke __rmul__, but 1*x would erroneously
148 invoke __mul__. This was due to the sequence-repeat code in the int
149 type. This has been fixed now.
150
Barry Warsawd79f6832002-08-06 17:01:51 +0000151- Previously, "str1 in str2" required str1 to be a string of length 1.
152 This restriction has been relaxed to allow str1 to be a string of
153 any length. Thus "'el' in 'hello world'" returns True now.
154
Guido van Rossumb57089c2002-08-06 16:20:26 +0000155- File objects are now their own iterators. For a file f, iter(f) now
156 returns f (unless f is closed), and f.next() is similar to
157 f.readline() when EOF is not reached; however, f.next() uses a
158 readahead buffer that messes up the file position, so mixing
159 f.next() and f.readline() (or other methods) doesn't work right.
160 Calling f.seek() drops the readahead buffer, but other operations
161 don't. It so happens that this gives a nice additional speed boost
162 to "for line in file:"; the xreadlines method and corresponding
Guido van Rossumbffb2ef2002-08-09 17:17:07 +0000163 module are now obsolete. Thanks to Oren Tirosh!
Guido van Rossumb57089c2002-08-06 16:20:26 +0000164
Guido van Rossumde392d32002-08-05 14:17:20 +0000165- Encoding declarations (PEP 263, phase 1) have been implemented. A
166 comment of the form "# -*- coding: <encodingname> -*-" in the first
167 or second line of a Python source file indicates the encoding.
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +0000168
Tim Petersf47630f2002-08-01 02:34:51 +0000169- list.sort() has a new implementation. While cross-platform results
170 may vary, and in data-dependent ways, this is much faster on many
171 kinds of partially ordered lists than the previous implementation,
172 and reported to be just as fast on randomly ordered lists on
173 several major platforms. This sort is also stable (if A==B and A
174 precedes B in the list at the start, A precedes B after the sort too),
175 although the language definition does not guarantee stability. A
176 potential drawback is that list.sort() may require temp space of
Skip Montanaroa2a07bc2002-09-30 15:23:01 +0000177 len(list)*2 bytes (``*4`` on a 64-bit machine). It's therefore possible
Tim Petersf47630f2002-08-01 02:34:51 +0000178 for list.sort() to raise MemoryError now, even if a comparison function
179 does not. See <http://www.python.org/sf/587076> for full details.
180
Guido van Rossum2d5389c2002-07-23 03:44:35 +0000181- All standard iterators now ensure that, once StopIteration has been
182 raised, all future calls to next() on the same iterator will also
183 raise StopIteration. There used to be various counterexamples to
184 this behavior, which could caused confusion or subtle program
185 breakage, without any benefits. (Note that this is still an
186 iterator's responsibility; the iterator framework does not enforce
187 this.)
188
Mark Hammondc0e35152002-07-16 01:32:30 +0000189- Ctrl+C handling on Windows has been made more consistent with
190 other platforms. KeyboardInterrupt can now reliably be caught,
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +0000191 and Ctrl+C at an interactive prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +0000192 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Tim Peters5af4e6c2002-08-12 02:31:19 +0000193 interrupt time.sleep() in the main thread, and any child processes
194 created via the popen family (on win2k; we can't make win9x work
Mark Hammond8f3afc72002-08-10 06:26:31 +0000195 reliably) are also interrupted (as generally happens on for Linux/Unix.)
196 [SF bugs 231273, 439992 and 581232]
Mark Hammondc0e35152002-07-16 01:32:30 +0000197
Mark Hammond8696ebc2002-10-08 02:44:31 +0000198- sys.getwindowsversion() has been added on Windows. This
199 returns a tuple with information about the version of Windows
200 currently running.
201
Raymond Hettinger5a04aec2002-06-25 00:25:30 +0000202- Slices and repetitions of buffer objects now consistently return
203 a string. Formerly, strings would be returned most of the time,
204 but a buffer object would be returned when the repetition count
205 was one or when the slice range was all inclusive.
206
Walter Dörwald3430d702002-06-17 10:43:59 +0000207- Unicode objects in sys.path are no longer ignored but treated
208 as directory names.
209
Neal Norwitz1f68fc72002-06-14 00:50:42 +0000210- Fixed string.startswith and string.endswith builtin methods
211 so they accept negative indices. [SF bug 493951]
212
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +0000213- Fixed a bug with a continue inside a try block and a yield in the
214 finally clause. [SF bug 567538]
215
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +0000216- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +0000217 with a third "stride" parameter. For example, "hello world"[::-1]
218 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +0000219
Neal Norwitzd68f5172002-05-29 15:54:55 +0000220- A new warning PendingDeprecationWarning was added to provide
221 direction on features which are in the process of being deprecated.
222 The warning will not be printed by default. To see the pending
223 deprecations, use -Walways::PendingDeprecationWarning::
224 as a command line option or warnings.filterwarnings() in code.
225
Fred Draked0ba6362002-05-02 21:28:26 +0000226- Deprecated features of xrange objects have been removed as
227 promised. The start, stop, and step attributes and the tolist()
228 method no longer exist. xrange repetition and slicing have been
229 removed.
230
Guido van Rossum7dab2422002-04-26 19:40:56 +0000231- New builtin function enumerate(x), from PEP 279. Example:
232 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
233 The argument can be an arbitrary iterable object.
234
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000235- The assert statement no longer tests __debug__ at runtime. This means
236 that assert statements cannot be disabled by assigning a false value
237 to __debug__.
238
Walter Dörwald068325e2002-04-15 13:36:47 +0000239- A method zfill() was added to str and unicode, that fills a numeric
240 string to the left with zeros. For example,
241 "+123".zfill(6) -> "+00123".
242
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000243- Complex numbers supported divmod() and the // and % operators, but
244 these make no sense. Since this was documented, they're being
245 deprecated now.
246
Guido van Rossum26dd8302002-04-26 20:11:29 +0000247- String and unicode methods lstrip(), rstrip() and strip() now take
248 an optional argument that specifies the characters to strip. For
249 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000250
Guido van Rossumc69343b2002-04-12 19:22:48 +0000251- Added a new dict method pop(key). This removes and returns the
252 value corresponding to key. [SF patch #539949]
253
Guido van Rossum47834462002-04-04 15:21:33 +0000254- A new built-in type, bool, has been added, as well as built-in
255 names for its two values, True and False. Comparisons and sundry
256 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000257 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000258 is backward compatible.
259
Guido van Rossum95b62a62002-03-29 01:07:24 +0000260- Fixed two bugs reported as SF #535905: under certain conditions,
261 deallocating a deeply nested structure could cause a segfault in the
262 garbage collector, due to interaction with the "trashcan" code;
263 access to the current frame during destruction of a local variable
264 could access a pointer to freed memory.
265
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000266- The optional object allocator ("pymalloc") has been enabled by
267 default. The recommended practice for memory allocation and
268 deallocation has been streamlined. A header file is included,
269 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
270 and lets them use the same API with Python versions from 1.5.2
271 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000272
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000273- PyErr_Display will provide file and line information for all exceptions
274 that have an attribute print_file_and_line, not just SyntaxErrors.
275
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000276- The UTF-8 codec will now encode and decode Unicode surrogates
277 correctly and without raising exceptions for unpaired ones.
278
Guido van Rossumadd88062002-08-15 14:01:14 +0000279- Universal newlines (PEP 278) is implemented. Briefly, using 'U'
280 instead of 'r' when opening a text file for reading changes the line
281 ending convention so that any of '\r', '\r\n', and '\n' is
282 recognized (even mixed in one file); all three are converted to
283 '\n', the standard Python line end character.
284
Neal Norwitz649b7592002-01-01 19:07:13 +0000285- file.xreadlines() now raises a ValueError if the file is closed:
286 Previously, an xreadlines object was returned which would raise
287 a ValueError when the xreadlines.next() method was called.
288
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000289- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000290 An exception will now be raised if more than one argument is used.
291
Tim Petersaf8446f2001-12-21 21:36:50 +0000292Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000293-----------------
Tim Petersaf8446f2001-12-21 21:36:50 +0000294
Neal Norwitz94a83fd2002-11-02 17:46:24 +0000295- resource.getrlimit() now returns longs instead of ints.
296
Martin v. Löwis080689c2002-10-26 14:42:02 +0000297- readline now dynamically adjusts its input/output stream if
298 sys.stdin/stdout changes.
299
Guido van Rossumba602972002-10-01 18:18:58 +0000300- The _tkinter module (and hence Tkinter) has dropped support for
301 Tcl/Tk 8.0 and 8.1. Only Tcl/Tk versions 8.2, 8.3 and 8.4 are
302 supported.
303
Martin v. Löwis658009a2002-09-16 17:26:24 +0000304- cPickle.BadPickleGet is now a class.
305
Martin v. Löwisa19bfe02002-10-16 18:28:36 +0000306- The time stamps in os.stat_result are floating point numbers
307 after stat_float_times has been called.
Martin v. Löwis94717ed2002-09-09 14:24:16 +0000308
Neal Norwitzb5673922002-09-05 21:48:07 +0000309- If the size passed to mmap.mmap() is larger than the length of the
310 file on non-Windows platforms, a ValueError is raised. [SF bug 585792]
311
Guido van Rossumb57089c2002-08-06 16:20:26 +0000312- The xreadlines module is slated for obsolescence.
313
Guido van Rossum79f0a102002-07-23 03:32:08 +0000314- The strptime function in the time module is now always available (a
315 Python implementation is used when the C library doesn't define it).
316
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000317- The 'new' module is no longer an extension, but a Python module that
318 only exists for backwards compatibility. Its contents are no longer
319 functions but callable type objects.
320
Tim Peters81b92512002-04-29 01:37:32 +0000321- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000322 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000323 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000324
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000325- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
326 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000327
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000328- The locale module now exposes the C library's gettext interface.
329
Tim Petersfbf74f22002-03-14 19:06:01 +0000330- A security hole ("double free") was found in zlib-1.1.3, a popular
331 third party compression library used by some Python modules. The
332 hole was quickly plugged in zlib-1.1.4, and the Windows build of
333 Python now ships with zlib-1.1.4.
334
Martin v. Löwis688357e2002-04-08 21:28:20 +0000335- pwd, grp, and resource return enhanced tuples now, with symbolic
336 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000337
Martin v. Löwis99866332002-03-01 10:27:01 +0000338- array.array is now a type object. A new format character
339 'u' indicates Py_UNICODE arrays. For those, .tounicode and
340 .fromunicode methods are available. Arrays now support __iadd__
341 and __imul__.
342
Neal Norwitze790eae2002-01-01 21:14:12 +0000343- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000344 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
345 is called.
346
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000347- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
348 been added where available.
349
Skip Montanaro8e790e72002-09-03 13:25:17 +0000350- The sys module acquired a new attribute, api_version, which evaluates
351 to the value of the PYTHON_API_VERSION macro with which the
352 interpreter was compiled.
353
Tim Petersaf8446f2001-12-21 21:36:50 +0000354Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000355-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000356
Martin v. Löwis74b51ac2002-10-26 14:50:45 +0000357- xml.sax.saxutils.unescape has been added, to replace entity references
358 with their entity value.
359
Martin v. Löwis77ac4292002-10-15 15:11:13 +0000360- Queue.Queue.{put,get} now support an optional timeout argument.
361
Martin v. Löwisb24e3472002-10-13 10:28:04 +0000362- Various features of Tk 8.4 are exposed in Tkinter.py. The multiple
363 option of tkFileDialog is exposed as function askopenfile{,name}s.
Martin v. Löwis2ec36272002-10-13 10:22:08 +0000364
Martin v. Löwisb24e3472002-10-13 10:28:04 +0000365- Various configure methods of Tkinter have been stream-lined, so that
366 tag_configure, image_configure, window_configure now return a
367 dictionary when invoked with no argument.
Martin v. Löwis6ce13152002-10-10 14:36:13 +0000368
Guido van Rossum2b492b62002-10-09 21:40:48 +0000369- Importing the readline module now no longer has the side effect of
370 calling setlocale(LC_CTYPE, ""). The initial "C" locale, or
371 whatever locale is explicitly set by the user, is preserved. If you
372 want repr() of 8-bit strings in your preferred encoding to preserve
373 all printable characters of that encoding, you have to add the
374 following code to your $PYTHONSTARTUP file or to your application's
375 main():
376
377 import locale
378 locale.setlocale(locale.LC_CTYPE, "")
379
Martin v. Löwise9ce0b02002-10-07 13:23:24 +0000380- shutil.move was added. shutil.copytree now reports errors as an
381 exception at the end, instead of printing error messages.
382
Marc-André Lemburg97047e22002-10-04 11:55:21 +0000383- Encoding name normalization was generalized to not only
384 replace hyphens with underscores, but also all other non-alphanumeric
385 characters (with the exception of the dot which is used for Python
386 package names during lookup). The aliases.py mapping was updated
387 to the new standard.
388
Walter Dörwald5ccaf8f2002-09-06 16:15:58 +0000389- mimetypes has two new functions: guess_all_extensions() which
390 returns a list of all known extensions for a mime type, and
391 add_type() which adds one mapping between a mime type and
392 an extension to the database.
393
Guido van Rossumd8ab35c2002-08-19 16:25:46 +0000394- New module: sets, defines the class Set that implements a mutable
395 set type using the keys of a dict to represent the set. There's
396 also a class ImmutableSet which is useful when you need sets of sets
397 or when you need to use sets as dict keys, and a class BaseSet which
398 is the base class of the two. (This is not documented yet, but
399 help(sets) gives a wealth of information.)
400
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +0000401- Added operator.pow(a,b) which is equivalent to a**b.
402
Tim Peters012c0a32002-08-16 03:40:07 +0000403- random.randrange(-sys.maxint-1, sys.maxint) no longer raises
404 OverflowError. That is, it now accepts any combination of 'start'
405 and 'stop' arguments so long as each is in the range of Python's
406 bounded integers.
407
Guido van Rossum4a57c332002-08-02 18:05:20 +0000408- New "algorithms" module: heapq, implements a heap queue. Thanks to
409 Kevin O'Connor for the code and François Pinard for an entertaining
410 write-up explaining the theory and practical uses of heaps.
411
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000412- New encoding for the Palm OS character set: palmos.
413
Tim Peters943382c2002-07-07 03:59:34 +0000414- binascii.crc32() and the zipfile module had problems on some 64-bit
415 platforms. These have been fixed. On a platform with 8-byte C longs,
416 crc32() now returns a signed-extended 4-byte result, so that its value
417 as a Python int is equal to the value computed a 32-bit platform.
418
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000419- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
420 argument.
421
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000422- Some fixes in the copy module: when an object is copied through its
423 __reduce__ method, there was no check for a __setstate__ method on
424 the result [SF patch 565085]; deepcopy should treat instances of
425 custom metaclasses the same way it treats instances of type 'type'
426 [SF patch 560794].
427
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000428- Sockets now support timeout mode. After s.settimeout(T), where T is
429 a float expressing seconds, subsequent operations raise an exception
430 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000431 mode, use s.settimeout(None). There's also a module function,
432 socket.setdefaulttimeout(T), which sets the default for all sockets
433 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000434
435- getopt.gnu_getopt was added. This supports GNU-style option
436 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000437
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000438- Stop using strings for exceptions. String objects used for
439 exceptions are now classes deriving from Exception. The objects
440 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
441 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000442
Walter Dörwald474458d2002-06-04 15:16:29 +0000443- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
444 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
445 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
446 big endian systems were added to the codecs module. The old names
447 BOM32_* and BOM64_* were off by a factor of 2.
448
Guido van Rossumf9257822002-06-18 20:43:18 +0000449- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000450
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000451- ftplib.retrlines() now tests for callback is None rather than testing
452 for False. Was causing an error when given a callback object which
453 was callable but also returned len() as zero. The change may
454 create new breakage if the caller relied on the undocumented behavior
455 and called with callback set to [] or some other False value not
456 identical to None.
457
Tim Peters46c04e12002-05-05 20:40:00 +0000458- random.gauss() uses a piece of hidden state used by nothing else,
459 and the .seed() and .whseed() methods failed to reset it. In other
460 words, setting the seed didn't completely determine the sequence of
461 results produced by random.gauss(). It does now. Programs repeatedly
462 mixing calls to a seed method with calls to gauss() may see different
463 results now.
464
Fred Drake7f781c92002-05-01 20:33:53 +0000465- The pickle.Pickler class grew a clear_memo() method to mimic that
466 provided by cPickle.Pickler.
467
Tim Peters81b92512002-04-29 01:37:32 +0000468- difflib's SequenceMatcher class now does a dynamic analysis of
469 which elements are so frequent as to constitute noise. For
470 comparing files as sequences of lines, this generally works better
471 than the IS_LINE_JUNK function, and function ndiff's linejunk
472 argument defaults to None now as a result. A happy benefit is
473 that SequenceMatcher may run much faster now when applied
474 to large files with many duplicate lines (for example, C program
475 text with lots of repeated "}" and "return NULL;" lines).
476
Guido van Rossum256705b2002-04-23 13:29:43 +0000477- New Text.dump() method in Tkinter module.
478
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000479- New distutils commands for building packagers were added to
480 support pkgtool on Solaris and swinstall on HP-UX.
481
482- distutils now has a new abstract binary packager base class
483 command/bdist_packager, which simplifies writing packagers.
484 This will hopefully provide the missing bits to encourage
485 people to submit more packagers, e.g. for Debian, FreeBSD
486 and other systems.
487
Guido van Rossumf9257822002-06-18 20:43:18 +0000488- The UTF-16, -LE and -BE stream readers now raise a
489 NotImplementedError for all calls to .readline(). Previously, they
490 used to just produce garbage or fail with an encoding error --
491 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 +0000492 work well with these.
493
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000494- compileall now supports quiet operation.
495
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000496- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000497 connections.
498
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000499- socket module: the SSL support was broken out of the main
500 _socket module C helper and placed into a new _ssl helper
501 which now gets imported by socket.py if available and working.
502
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000503- encodings package: added aliases for all supported IANA character
504 sets
505
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000506- ftplib: to safeguard the user's privacy, anonymous login will use
507 "anonymous@" as default password, rather than the real user and host
508 name.
509
Fred Drake36736122002-01-10 13:50:31 +0000510- webbrowser: tightened up the command passed to os.system() so that
511 arbitrary shell code can't be executed because a bogus URL was
512 passed in.
513
Tim Peters11bd9942002-02-01 00:52:29 +0000514- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000515 gettext.find an optional all argument. Translations will now fallback
516 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000517
Martin v. Löwis9668b932002-01-12 11:27:42 +0000518- distutils bdist commands now offer a --skip-build option.
519
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000520- warnings.warn now accepts a Warning instance as first argument.
521
Fred Drakefed7e852002-04-04 19:36:15 +0000522- The xml.sax.expatreader.ExpatParser class will no longer create
523 circular references by using itself as the locator that gets passed
524 to the content handler implementation. [SF bug #535474]
525
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000526- The email.Parser.Parser class now properly parses strings regardless
527 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
528 or CRLF). Also, the Header class's constructor default arguments
529 has changed slightly so that an explicit maxlinelen value is always
530 honored.
531
Tim Petersaf8446f2001-12-21 21:36:50 +0000532Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000533-----------
Tim Petersaf8446f2001-12-21 21:36:50 +0000534
Guido van Rossum923e4ef2002-09-17 20:58:59 +0000535- The SGI demos (Demo/sgi) have been removed. Nobody thought they
536 were interesting any more. (The SGI library modules and extensions
537 are still there; it is believed that at least some of these are
538 still used and useful.)
539
Fred Drake40813b12002-08-05 15:24:19 +0000540- IDLE supports the new encoding declarations (PEP 263); it can also
541 deal with legacy 8-bit files if they use the locale's encoding. It
542 allows non-ASCII strings in the interactive shell and executes them
543 in the locale's encoding.
Martin v. Löwis98ce7b72002-08-05 15:11:26 +0000544
Marc-André Lemburg46260092002-04-04 16:17:11 +0000545- freeze.py now produces binaries which can import shared modules,
546 unlike before when this failed due to missing symbol exports in
547 the generated binary.
548
Tim Petersaf8446f2001-12-21 21:36:50 +0000549Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000550-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000551
Guido van Rossum6b3db552002-09-25 15:02:44 +0000552- The fpectl module is not built by default; it's dangerous or useless
553 except in the hands of experts.
554
Tim Petersf47630f2002-08-01 02:34:51 +0000555- The public Python C API will generally be declared using PyAPI_FUNC
Guido van Rossum6b3db552002-09-25 15:02:44 +0000556 and PyAPI_DATA macros, while Python extension module init functions
557 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
558 are deprecated.
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000559
Tim Petersc6a3ff62002-07-08 22:11:52 +0000560- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
561 get into infinite loops, when a new-style class got garbage-collected.
562 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
563 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
564 COUNT_ALLOCS is not enabled by default, in either release or debug
565 builds, and that new-style classes are immortal only in COUNT_ALLOCS
566 builds.
567
Tim Peters943382c2002-07-07 03:59:34 +0000568- Compiling out the cyclic garbage collector is no longer an option.
569 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
570 that it's always defined (for the benefit of any extension modules
571 that may be conditionalizing on it). A bonus is that any extension
572 type participating in cyclic gc can choose to participate in the
573 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
574 to require editing the core to teach the trashcan mechanism about the
575 new type.
576
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000577- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000578
579 The Standard C macro HUGE_VAL and its float and long double analogs,
580 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
581 positive infinities.
582
583 Python only uses the double HUGE_VAL, and only to #define its own symbol
584 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
585 pyport.h used to try to worm around that, but the workarounds triggered
586 other bugs on other platforms, so we gave up. If your platform defines
587 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
588 that works on your platform. The only instance of this I'm sure about
589 is on an unknown subset of Cray systems, described here:
590
591 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
592
593 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
594
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000595- The configure option --without-doc-strings can be used to remove the
596 doc strings from the builtin functions and modules; this reduces the
597 size of the executable.
598
Guido van Rossumadd88062002-08-15 14:01:14 +0000599- The universal newlines option (PEP 278) is on by default. On Unix
600 it can be disabled by passing --without-universal-newlines to the
601 configure script. On other platforms, remove
602 WITH_UNIVERSAL_NEWLINES from pyconfig.h.
Tim Peters639295f2002-04-21 07:30:30 +0000603
Martin v. Löwis1142de32002-03-29 16:28:31 +0000604- On Unix, a shared libpython2.3.so can be created with --enable-shared.
605
Tim Peters8deda702002-03-30 10:06:07 +0000606- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
607 preprocessor symbols were eliminated. The internal decisions they
608 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000609
Fred Drake7d28b732002-05-02 21:17:00 +0000610- The tools used to build the documentation now work under Cygwin as
611 well as Unix.
612
Skip Montanaro57454e52002-06-14 20:30:31 +0000613- The bsddb and dbm module builds have been changed to try and avoid version
614 skew problems and disable linkage with Berkeley DB 1.85 unless the
615 installer knows what s/he's doing. See the section on building these
616 modules in the README file for details.
617
Tim Petersaf8446f2001-12-21 21:36:50 +0000618C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000619-----
Tim Petersaf8446f2001-12-21 21:36:50 +0000620
Guido van Rossum45ec02a2002-08-19 21:43:18 +0000621- The string object's layout has changed: the pointer member
622 ob_sinterned has been replaced by an int member ob_sstate. On some
623 platforms (e.g. most 64-bit systems) this may change the offset of
624 the ob_sval member, so as a precaution the API_VERSION has been
625 incremented. The apparently unused feature of "indirect interned
626 strings", supported by the ob_sinterned member, is gone. Interned
627 strings are now usually mortal; theres a new API,
628 PyString_InternImmortal() that creates immortal interned strings.
629 (The ob_sstate member can only take three values; however, while
630 making it a char saves a few bytes per string object on average, in
631 it also slowed things down a bit because ob_sval was no longer
632 aligned.)
633
Guido van Rossumfdb86482002-08-14 21:20:32 +0000634- The Py_InitModule*() functions now accept NULL for the 'methods'
635 argument. Modules without global functions are becoming more common
636 now that factories can be types rather than functions.
637
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000638- New C API PyUnicode_FromOrdinal() which exposes unichr() at C
639 level.
640
Thomas Heller085358a2002-07-29 14:27:41 +0000641- New functions PyErr_SetExcFromWindowsErr() and
642 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
643 PyErr_SetFromWindowsErrWithFilename() and
644 PyErr_SetFromWindowsErr(), but they allow to specify
645 the exception type to raise. Available on Windows.
646
Tim Peters7c321a82002-07-09 02:57:01 +0000647- Py_FatalError() is now declared as taking a const char* argument. It
648 was previously declared without const. This should not affect working
649 code.
650
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000651- Added new macro PySequence_ITEM(o, i) that directly calls
652 sq_item without rechecking that o is a sequence and without
653 adjusting for negative indices.
654
Fred Draked0ba6362002-05-02 21:28:26 +0000655- PyRange_New() now raises ValueError if the fourth argument is not 1.
656 This is part of the removal of deprecated features of the xrange
657 object.
658
Guido van Rossum517c7d42002-04-26 02:49:14 +0000659- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
660 coercion if both arguments have the same type but this type has the
661 CHECKTYPES flag set. This is to better support proxies.
662
Skip Montanaroa2a07bc2002-09-30 15:23:01 +0000663- The type of tp_free has been changed from "``void (*)(PyObject *)``" to
664 "``void (*)(void *)``".
Neil Schemenauer9344b142002-04-12 23:00:08 +0000665
666- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
667
Guido van Rossum0986d822002-04-08 01:38:42 +0000668- A type can now inherit its metatype from its base type. Previously,
669 when PyType_Ready() was called, if ob_type was found to be NULL, it
670 was always set to &PyType_Type; now it is set to base->ob_type,
671 where base is tp_base, defaulting to &PyObject_Type.
672
673- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
674
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000675- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000676
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000677- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000678 without going through the buffer API.
679
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000680- The enumerators of cmp_op have been renamed to use the prefix ``PyCmp_``.
Martin v. Löwis7198a522002-01-01 19:59:11 +0000681
Tim Peters10a3bb52001-12-25 19:07:38 +0000682- An old #define of ANY as void has been removed from pyport.h. This
683 hasn't been used since Python's pre-ANSI days, and the #define has
684 been marked as obsolete since then. SF bug 495548 says it created
685 conflicts with other packages, so keeping it around wasn't harmless.
686
Tim Petersaf8446f2001-12-21 21:36:50 +0000687- Because Python's magic number scheme broke on January 1st, we decided
688 to stop Python development. Thanks for all the fish!
689
Tim Petersfb05db22002-03-11 00:24:00 +0000690- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000691 scheme to a new one. See Python/import.c for details.
692
Tim Petersaf8446f2001-12-21 21:36:50 +0000693New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000694-------------
Tim Petersaf8446f2001-12-21 21:36:50 +0000695
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000696- AtheOS is now supported.
697
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000698- the EMX runtime environment on OS/2 is now supported.
699
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000700- GNU/Hurd is now supported.
701
Tim Petersaf8446f2001-12-21 21:36:50 +0000702Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000703-----
704
705Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000706
707Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000708-------
Tim Petersaf8446f2001-12-21 21:36:50 +0000709
Tim Peters08e72952002-04-16 20:48:01 +0000710- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
711 of that has been fixed in the installer (disabled Wise's "delete in-
712 use files" uninstall option).
713
Guido van Rossum181e41a2002-04-06 00:23:25 +0000714- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
715
Tim Peters33187922002-04-04 20:02:04 +0000716- The installer now installs Start menu shortcuts under (the local
717 equivalent of) "All Users" when doing an Admin install.
718
Tim Petersfb05db22002-03-11 00:24:00 +0000719- file.truncate([newsize]) now works on Windows for all newsize values.
720 It used to fail if newsize didn't fit in 32 bits, reflecting a
721 limitation of MS _chsize (which is no longer used).
722
Tim Petersab034fa2002-02-01 11:27:43 +0000723- os.waitpid() is now implemented for Windows, and can be used to block
724 until a specified process exits. This is similar to, but not exactly
725 the same as, os.waitpid() on POSIX systems. If you're waiting for
726 a specific process whose pid was obtained from one of the spawn()
727 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000728 See the docs for details. The docs were changed to clarify that
729 spawn functions return, and waitpid requires, a process handle on
730 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000731
Tim Peters11bd9942002-02-01 00:52:29 +0000732- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000733 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000734 to a nasty problem: before 2.3, if you got a temp file on Windows, it
735 got wrapped in an object whose close() method first closed the
736 underlying file, then deleted the file. This usually worked fine.
737 However, the spawn family of functions on Windows create (at a low C
738 level) the same set of open files in the spawned process Q as were
739 open in the spawning process P. If a temp file f was among them, then
740 doing f.close() in P first closed P's C-level file handle on f, but Q's
741 C-level file handle on f remained open, so the attempt in P to delete f
742 blew up with a "Permission denied" error (Windows doesn't allow
743 deleting open files). This was surprising, subtle, and difficult to
744 work around.
745
746- The os module now exports all the symbolic constants usable with the
747 low-level os.open() on Windows: the new constants in 2.3 are
748 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
749 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
750 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
751 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
752 (so specify both if you want both; note that neither is useful unless
753 specified with O_CREAT too).
754
Tim Petersaf8446f2001-12-21 21:36:50 +0000755Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000756----
757
758Yet to be written.
Tim Petersaf8446f2001-12-21 21:36:50 +0000759
760
Tim Peters909c0912001-12-14 23:16:18 +0000761What's New in Python 2.2 final?
Tim Peters909c0912001-12-14 23:16:18 +0000762===============================
763
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000764*Release date: 21-Dec-2001*
765
Tim Peters909c0912001-12-14 23:16:18 +0000766Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000767--------------------------------------------
Tim Peters909c0912001-12-14 23:16:18 +0000768
Barry Warsaw52acb492001-12-21 20:04:22 +0000769- pickle.py, cPickle: allow pickling instances of new-style classes
770 with a custom metaclass.
771
Tim Peters909c0912001-12-14 23:16:18 +0000772Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000773-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000774
Barry Warsaw52acb492001-12-21 20:04:22 +0000775- weakref proxy object: when comparing, unwrap both arguments if both
776 are proxies.
777
Tim Peters909c0912001-12-14 23:16:18 +0000778Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000779-----------------
Tim Peters909c0912001-12-14 23:16:18 +0000780
Barry Warsaw52acb492001-12-21 20:04:22 +0000781- binascii.b2a_base64(): fix a potential buffer overrun when encoding
782 very short strings.
783
784- cPickle: the obscure "fast" mode was suspected of causing stack
785 overflows on the Mac. Hopefully fixed this by setting the recursion
786 limit much smaller. If the limit is too low (it only affects
787 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
788 when compiling cPickle.c (or in pyconfig.h).
789
Tim Peters909c0912001-12-14 23:16:18 +0000790Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000791-------
Tim Peters909c0912001-12-14 23:16:18 +0000792
Barry Warsaw52acb492001-12-21 20:04:22 +0000793- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
794 close or delete time).
795
796- rfc822.py: fixed a bug where the address '<>' was converted to None
797 instead of an empty string (also fixes the email.Utils module).
798
799- xmlrpclib.py: version 1.0.0; uses precision for doubles.
800
801- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000802 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000803
Tim Peters909c0912001-12-14 23:16:18 +0000804Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000805-----------
Tim Peters909c0912001-12-14 23:16:18 +0000806
807Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000808-----
Tim Peters909c0912001-12-14 23:16:18 +0000809
810C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000811-----
Tim Peters909c0912001-12-14 23:16:18 +0000812
813New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000814-------------
Tim Peters909c0912001-12-14 23:16:18 +0000815
816Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000817-----
Tim Peters909c0912001-12-14 23:16:18 +0000818
819Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000820-------
Tim Peters909c0912001-12-14 23:16:18 +0000821
Barry Warsaw52acb492001-12-21 20:04:22 +0000822- distutils package: fixed broken Windows installers (bdist_wininst).
823
824- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
825 instances are deleted at process exit time.
826
827- socket.py: prevent mysterious warnings when socket instances are
828 deleted at process exit time.
829
830- posixmodule.c: fix a Windows crash with stat() of a filename ending
831 in backslash.
832
Tim Peters909c0912001-12-14 23:16:18 +0000833Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000834----
Tim Peters909c0912001-12-14 23:16:18 +0000835
Barry Warsaw52acb492001-12-21 20:04:22 +0000836- The Carbon toolbox modules have been upgraded to Universal Headers
837 3.4, and experimental CoreGraphics and CarbonEvents modules have
838 been added. All only for framework-enabled MacOSX.
839
Tim Peters909c0912001-12-14 23:16:18 +0000840
Tim Peters6272dfd2001-12-13 19:34:00 +0000841What's New in Python 2.2c1?
Tim Petersb3c9af12001-11-17 00:21:57 +0000842===========================
843
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000844*Release date: 14-Dec-2001*
845
Tim Petersb3c9af12001-11-17 00:21:57 +0000846Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000847--------------------------------------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000848
Barry Warsaw06557452001-12-14 20:47:12 +0000849- Guido's tutorial introduction to the new type/class features has
850 been extensively updated. See
851
852 http://www.python.org/2.2/descrintro.html
853
854 That remains the primary documentation in this area.
855
Guido van Rossum33bab012001-12-05 22:45:48 +0000856- Fixed a leak: instance variables declared with __slots__ were never
857 deleted!
858
Guido van Rossum4b800852001-12-03 00:54:52 +0000859- The "delete attribute" method of descriptor objects is called
860 __delete__, not __del__. In previous releases, it was mistakenly
861 called __del__, which created an unfortunate overloading condition
862 with finalizers. (The "get attribute" and "set attribute" methods
863 are still called __get__ and __set__, respectively.)
864
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000865- Some subtle issues with the super built-in were fixed:
866
867 (a) When super itself is subclassed, its __get__ method would still
868 return an instance of the base class (i.e., of super).
869
870 (b) super(C, C()).__class__ would return C rather than super. This
871 is confusing. To fix this, I decided to change the semantics of
872 super so that it only applies to code attributes, not to data
873 attributes. After all, overriding data attributes is not
874 supported anyway.
875
876 (c) The __get__ method didn't check whether the argument was an
877 instance of the type used in creation of the super instance.
878
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000879- Previously, hash() of an instance of a subclass of a mutable type
880 (list or dictionary) would return some value, rather than raising
881 TypeError. This has been fixed. Also, directly calling
882 dict.__hash__ and list.__hash__ now raises the same TypeError
883 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000884
Guido van Rossumd331cb52001-12-05 19:46:42 +0000885- New-style objects now support deleting their __dict__. This is for
886 all intents and purposes equivalent to assigning a brand new empty
887 dictionary, but saves space if the object is not used further.
888
Tim Petersb3c9af12001-11-17 00:21:57 +0000889Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000890-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000891
Tim Peters3caca232001-12-06 06:23:26 +0000892- -Qnew now works as documented in PEP 238: when -Qnew is passed on
893 the command line, all occurrences of "/" use true division instead
894 of classic division. See the PEP for details. Note that "all"
895 means all instances in library and 3rd-party modules, as well as in
896 your own code. As the PEP says, -Qnew is intended for use only in
897 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000898 Note that test_coercion.py in the standard Python test suite fails
899 under -Qnew; this is expected, and won't be repaired until true
900 division becomes the default (in the meantime, test_coercion is
901 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000902
Fred Drake6c01e252001-12-14 17:08:12 +0000903- complex() now only allows the first argument to be a string
904 argument, and raises TypeError if either the second arg is a string
905 or if the second arg is specified when the first is a string.
906
Tim Petersb3c9af12001-11-17 00:21:57 +0000907Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000908-----------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000909
Martin v. Löwis560da622001-11-24 09:24:51 +0000910- gc.get_referents was renamed to gc.get_referrers.
911
Tim Petersb3c9af12001-11-17 00:21:57 +0000912Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000913-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000914
Tim Peters25059d32001-12-07 20:35:43 +0000915- Functions in the os.spawn() family now release the global interpreter
916 lock around calling the platform spawn. They should always have done
917 this, but did not before 2.2c1. Multithreaded programs calling
918 an os.spawn function with P_WAIT will no longer block all Python threads
919 until the spawned program completes. It's possible that some programs
920 relies on blocking, although more likely by accident than by design.
921
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000922- webbrowser defaults to netscape.exe on OS/2 now.
923
Martin v. Löwis652e1912001-11-25 14:50:56 +0000924- Tix.ResizeHandle exposes detach_widget, hide, and show.
925
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000926- The charset alias windows_1252 has been added.
927
Barry Warsaw06557452001-12-14 20:47:12 +0000928- types.StringTypes is a tuple containing the defined string types;
929 usually this will be (str, unicode), but if Python was compiled
930 without Unicode support it will be just (str,).
931
932- The pulldom and minidom modules were synchronized to PyXML.
933
Tim Petersb3c9af12001-11-17 00:21:57 +0000934Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000935-----------
Tim Petersb3c9af12001-11-17 00:21:57 +0000936
Barry Warsaw06557452001-12-14 20:47:12 +0000937- A new script called Tools/scripts/google.py was added, which fires
938 off a search on Google.
939
Tim Petersb3c9af12001-11-17 00:21:57 +0000940Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000941-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000942
Barry Warsaw06557452001-12-14 20:47:12 +0000943- Note that release builds of Python should arrange to define the
944 preprocessor symbol NDEBUG on the command line (or equivalent).
945 In the 2.2 pre-release series we tried to define this by magic in
946 Python.h instead, but it proved to cause problems for extension
947 authors. The Unix, Windows and Mac builds now all define NDEBUG in
948 release builds via cmdline (or equivalent) instead. Ports to
949 other platforms should do likewise.
950
Jack Jansen1999ef42001-12-06 21:47:20 +0000951- It is no longer necessary to use --with-suffix when building on a
952 case-insensitive file system (such as Mac OS X HFS+). In the build
953 directory an extension is used, but not in the installed python.
954
Tim Petersb3c9af12001-11-17 00:21:57 +0000955C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000956-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000957
Tim Petersf582b822001-12-11 18:51:08 +0000958- New function PyDict_MergeFromSeq2() exposes the builtin dict
959 constructor's logic for updating a dictionary from an iterable object
960 producing key-value pairs.
961
Tim Peterscffed4b2001-11-29 03:26:37 +0000962- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000963 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000964 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
965 dump core in some bad cases. This has been repaired. As a result,
966 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
967 previously went unchallenged.
968
Tim Petersb3c9af12001-11-17 00:21:57 +0000969New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000970-------------
Tim Petersb3c9af12001-11-17 00:21:57 +0000971
972Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000973-----
Tim Petersb3c9af12001-11-17 00:21:57 +0000974
975Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000976-------
Tim Petersb3c9af12001-11-17 00:21:57 +0000977
978Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000979----
Tim Petersb3c9af12001-11-17 00:21:57 +0000980
Jack Jansenffa260f2001-12-06 21:14:00 +0000981- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
982 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000983
Barry Warsaw06557452001-12-14 20:47:12 +0000984- Changed logic for finding python home in Mac OS X framework Pythons.
985 Now sys.executable points to the executable again, in stead of to
986 the shared library. The latter is used only for locating the python
987 home.
988
989
Tim Peters84362bc2001-10-19 17:55:30 +0000990What's New in Python 2.2b2?
Tim Peters84362bc2001-10-19 17:55:30 +0000991===========================
992
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000993*Release date: 16-Nov-2001*
994
Tim Peters84362bc2001-10-19 17:55:30 +0000995Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +0000996--------------------------------------------
Tim Peters84362bc2001-10-19 17:55:30 +0000997
Guido van Rossum3d27df02001-11-15 20:27:54 +0000998- Multiple inheritance mixing new-style and classic classes in the
999 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +00001000
1001 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +00001002 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +00001003
1004 The MRO (method resolution order) for each base class is respected
1005 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001006 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +00001007 This needs to be documented.
1008
Tim Petersa427a2b2001-10-29 22:25:45 +00001009- The new builtin dictionary() constructor, and dictionary type, have
1010 been renamed to dict. This reflects a decade of common usage.
1011
Guido van Rossum3fc08d22001-11-15 20:33:10 +00001012- dict() now accepts an iterable object producing 2-sequences. For
1013 example, dict(d.items()) == d for any dictionary d. The argument,
1014 and the elements of the argument, can be any iterable objects.
1015
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +00001016- New-style classes can now have a __del__ method, which is called
1017 when the instance is deleted (just like for classic classes).
1018
Guido van Rossum12d955c2001-10-26 14:56:06 +00001019- Assignment to object.__dict__ is now possible, for objects that are
1020 instances of new-style classes that have a __dict__ (unless the base
1021 class forbids it).
1022
Guido van Rossumc8e56452001-10-22 00:43:43 +00001023- Methods of built-in types now properly check for keyword arguments
1024 (formerly these were silently ignored). The only built-in methods
1025 that take keyword arguments are __call__, __init__ and __new__.
1026
Guido van Rossum86443212001-10-27 22:28:54 +00001027- The socket function has been converted to a type; see below.
1028
Tim Peters84362bc2001-10-19 17:55:30 +00001029Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001030-----------------
Tim Peters84362bc2001-10-19 17:55:30 +00001031
Jeremy Hylton249aaed2001-11-09 21:06:24 +00001032- Assignment to __debug__ raises SyntaxError at compile-time. This
1033 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +00001034 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +00001035
Guido van Rossum12d955c2001-10-26 14:56:06 +00001036- Clarified the error messages for unsupported operands to an operator
1037 (like 1 + '').
1038
Tim Peters84362bc2001-10-19 17:55:30 +00001039Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001040-----------------
Tim Peters84362bc2001-10-19 17:55:30 +00001041
Tim Peters5ebfd362001-11-13 23:11:19 +00001042- mmap has a new keyword argument, "access", allowing a uniform way for
1043 both Windows and Unix users to create read-only, write-through and
1044 copy-on-write memory mappings. This was previously possible only on
1045 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001046 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +00001047 platforms. Thanks to Jay T Miller for repairing this!
1048
Tim Peters169ded02001-11-03 19:57:21 +00001049- By default, the gc.garbage list now contains only those instances in
1050 unreachable cycles that have __del__ methods; in 2.1 it contained all
1051 instances in unreachable cycles. "Instances" here has been generalized
1052 to include instances of both new-style and old-style classes.
1053
Guido van Rossum12d955c2001-10-26 14:56:06 +00001054- The socket module defines a new method for socket objects,
1055 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +00001056 send() until all data has been sent. Also, the socket function has
1057 been converted to a subclassable type, like list and tuple (etc.)
1058 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +00001059
1060- Various bugfixes to the curses module. There is now a test suite
1061 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001062
Guido van Rossum692adf12001-10-30 03:03:03 +00001063- binascii.b2a_base64 no longer places an arbitrary restriction of 57
1064 bytes on its input.
1065
Tim Peters84362bc2001-10-19 17:55:30 +00001066Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001067-------
Tim Peters84362bc2001-10-19 17:55:30 +00001068
Tim Peters5ebfd362001-11-13 23:11:19 +00001069- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +00001070 convenience function.
1071
Tim Peters75335872001-11-03 19:35:43 +00001072- Symbolic group names in regular expressions must be unique. For
1073 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
1074 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +00001075 Python 2.2 detects this error at regexp compilation time;
1076 previously, the error went undetected, and results were
1077 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
1078 pattern.subn() methods have been rewritten in C. Also, an
1079 experimental function/method finditer() has been added, which works
1080 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +00001081
Martin v. Löwisb7b32602001-11-02 23:48:20 +00001082- Tix exposes more commands through the classes DirSelectBox,
1083 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
1084 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
1085 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
1086
Tim Peters98791af2001-10-23 01:59:54 +00001087- Traceback objects are now scanned by cyclic garbage collection, so
1088 cycles created by casual use of sys.exc_info() no longer cause
1089 permanent memory leaks (provided garbage collection is enabled).
1090
Guido van Rossum49192142001-10-24 20:51:44 +00001091- os.extsep -- a new variable needed by the RISCOS support. It is the
1092 separator used by extensions, and is '.' on all platforms except
1093 RISCOS, where it is '/'. There is no need to use this variable
1094 unless you have a masochistic desire to port your code to RISCOS.
1095
Barry Warsaw012852b2001-11-16 16:17:27 +00001096- mimetypes.py has optional support for non-standard, but commonly
1097 found types. guess_type() and guess_extension() now accept an
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001098 optional 'strict' flag, defaulting to true, which controls whether
Barry Warsaw012852b2001-11-16 16:17:27 +00001099 recognize non-standard types or not. A few non-standard types we
1100 know about have been added. Also, when run as a script, there are
1101 new -l and -e options.
1102
1103- statcache is now deprecated.
1104
1105- email.Utils.formatdate() now produces the preferred RFC 2822 style
1106 dates with numeric timezones (it used to produce obsolete dates
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001107 hard coded to "GMT" timezone). An optional 'localtime' flag is
Barry Warsaw012852b2001-11-16 16:17:27 +00001108 added to produce dates in the local timezone, with daylight savings
1109 time properly taken into account.
1110
1111- In pickle and cPickle, instead of masking errors in load() by
1112 transforming them into SystemError, we let the original exception
1113 propagate out. Also, implement support for __safe_for_unpickling__
1114 in pickle, as it already was supported in cPickle.
1115
Tim Peters84362bc2001-10-19 17:55:30 +00001116Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001117-----------
Tim Peters84362bc2001-10-19 17:55:30 +00001118
1119Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001120-----
Tim Peters84362bc2001-10-19 17:55:30 +00001121
Barry Warsaw012852b2001-11-16 16:17:27 +00001122- The dbm module is built using libdb1 if available. The bsddb module
1123 is built with libdb3 if available.
1124
1125- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
1126
Tim Peters84362bc2001-10-19 17:55:30 +00001127C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001128-----
Tim Peters84362bc2001-10-19 17:55:30 +00001129
Tim Peters1fc240e2001-10-26 05:06:50 +00001130- New function PySequence_Fast_GET_SIZE() returns the size of a non-
1131 NULL result from PySequence_Fast(), more quickly than calling
1132 PySequence_Size().
1133
Barry Warsaw012852b2001-11-16 16:17:27 +00001134- New argument unpacking function PyArg_UnpackTuple() added.
1135
1136- New functions PyObject_CallFunctionObjArgs() and
1137 PyObject_CallMethodObjArgs() have been added to make it more
1138 convenient and efficient to call functions and methods from C.
1139
1140- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
1141 possible that this will propagate errors it didn't before.
1142
1143- New function PyObject_CheckReadBuffer(), which returns true if its
1144 argument supports the single-segment readable buffer interface.
1145
Tim Peters84362bc2001-10-19 17:55:30 +00001146New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001147-------------
Tim Peters84362bc2001-10-19 17:55:30 +00001148
Guido van Rossum86443212001-10-27 22:28:54 +00001149- We've finally confirmed that this release builds on HP-UX 11.00,
1150 *with* threads, and passes the test suite.
1151
Tim Peters7a33d8b2001-11-05 02:51:07 +00001152- Thanks to a series of patches from Michael Muller, Python may build
1153 again under OS/2 Visual Age C++.
1154
Guido van Rossum49192142001-10-24 20:51:44 +00001155- Updated RISCOS port by Dietmar Schwertberger.
1156
Tim Peters84362bc2001-10-19 17:55:30 +00001157Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001158-----
Tim Peters84362bc2001-10-19 17:55:30 +00001159
Andrew M. Kuchling15e03532001-10-22 16:37:10 +00001160- Added a test script for the curses module. It isn't run automatically;
1161 regrtest.py must be run with '-u curses' to enable it.
1162
Tim Peters84362bc2001-10-19 17:55:30 +00001163Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001164-------
Tim Peters84362bc2001-10-19 17:55:30 +00001165
Barry Warsaw012852b2001-11-16 16:17:27 +00001166Mac
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001167----
Barry Warsaw012852b2001-11-16 16:17:27 +00001168
1169- PythonScript has been moved to unsupported and is slated to be
1170 removed completely in the next release.
1171
1172- It should now be possible to build applets that work on both OS9 and
1173 OSX.
1174
1175- The core is now linked with CoreServices not Carbon; as a side
1176 result, default 8bit encoding on OSX is now ASCII.
1177
1178- Python should now build on OSX 10.1.1
1179
Tim Peters84362bc2001-10-19 17:55:30 +00001180
Tim Petersabf925f2001-09-28 21:53:42 +00001181What's New in Python 2.2b1?
Tim Petersabf925f2001-09-28 21:53:42 +00001182===========================
1183
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001184*Release date: 19-Oct-2001*
1185
Tim Petersabf925f2001-09-28 21:53:42 +00001186Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001187--------------------------------------------
Tim Petersabf925f2001-09-28 21:53:42 +00001188
Guido van Rossum687ae002001-10-15 22:03:32 +00001189- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001190 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +00001191 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001192 remains: the __dict__ of a new-style class is a read-only proxy; you
1193 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +00001194 __defined__ attribute of new-style types no longer exists, for lack
1195 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +00001196 future a __cache__ may be resurrected with a similar function, if I
1197 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +00001198
Tim Peters1c9ca872001-10-04 06:43:12 +00001199- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
1200 always returned None, even when there was a class docstring).
1201
1202- doctest now finds and runs docstrings attached to new-style classes,
1203 class methods, static methods, and properties.
1204
Guido van Rossum9074ef62001-10-16 21:34:49 +00001205Core and builtins
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001206-----------------
Tim Petersabf925f2001-09-28 21:53:42 +00001207
Guido van Rossuma8bcf802001-10-15 15:53:58 +00001208- A very subtle syntactical pitfall in list comprehensions was fixed.
1209 For example: [a+b for a in 'abc', for b in 'def']. The comma in
1210 this example is a mistake. Previously, this would silently let 'a'
1211 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
1212 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
1213 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
1214 Note that [a for a in <singleton>] is a convoluted way to say
1215 [<singleton>] anyway, so it's not like any expressiveness is lost.
1216
Guido van Rossum9074ef62001-10-16 21:34:49 +00001217- getattr(obj, name, default) now only catches AttributeError, as
1218 documented, rather than returning the default value for all
1219 exceptions (which could mask bugs in a __getattr__ hook, for
1220 example).
1221
Fred Drakecb7a6b52001-10-22 18:41:51 +00001222- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +00001223 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001224 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +00001225 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +00001226
Guido van Rossum1c486092001-10-19 02:05:35 +00001227- unicode(obj) now behaves more like str(obj), accepting arbitrary
1228 objects, and calling a __unicode__ method if it exists.
1229 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +00001230 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +00001231
Barry Warsawf6fb1712001-10-19 05:35:40 +00001232- isinstance() now allows any object as the first argument and a
1233 class, a type or something with a __bases__ tuple attribute for the
1234 second argument. The second argument may also be a tuple of a
1235 class, type, or something with __bases__, in which case isinstance()
1236 will return true if the first argument is an instance of any of the
1237 things contained in the second argument tuple. E.g.
1238
1239 isinstance(x, (A, B))
1240
1241 returns true if x is an instance of A or B.
1242
Guido van Rossum9074ef62001-10-16 21:34:49 +00001243Extension modules
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001244-----------------
Guido van Rossum9074ef62001-10-16 21:34:49 +00001245
1246- thread.start_new_thread() now returns the thread ID (previously None).
1247
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001248- binascii has now two quopri support functions, a2b_qp and b2a_qp.
1249
Guido van Rossumc524d952001-10-19 01:31:59 +00001250- readline now supports setting the startup_hook and the
1251 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +00001252
Guido van Rossumc524d952001-10-19 01:31:59 +00001253- os and posix supports chroot(), setgroups() and unsetenv() where
1254 available. The stat(), fstat(), statvfs() and fstatvfs() functions
1255 now return "pseudo-sequences" -- the various fields can now be
1256 accessed as attributes (e.g. os.stat("/").st_mtime) but for
1257 backwards compatibility they also behave as a fixed-length sequence.
1258 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +00001259 attributes.
1260
1261- time: localtime(), gmtime() and strptime() now return a
1262 pseudo-sequence similar to the os.stat() return value, with
1263 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +00001264
Guido van Rossum9074ef62001-10-16 21:34:49 +00001265- Decompression objects in the zlib module now accept an optional
1266 second parameter to decompress() that specifies the maximum amount
1267 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +00001268
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001269- optional SSL support in the socket module now exports OpenSSL
1270 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
1271 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +00001272 automatically seed its PRNG. Also, the keyfile and certfile
1273 arguments to socket.ssl() are now optional.
1274
1275- posixmodule (and by extension, the os module on POSIX platforms) now
1276 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001277
Guido van Rossum9074ef62001-10-16 21:34:49 +00001278Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001279-------
Guido van Rossum3c288632001-10-16 21:13:49 +00001280
Tim Peters7402f792001-10-02 03:53:41 +00001281- doctest now excludes functions and classes not defined by the module
1282 being tested, thanks to Tim Hochberg.
1283
Fred Drakecb7a6b52001-10-22 18:41:51 +00001284- HotShot, a new profiler implemented using a C-based callback, has
1285 been added. This substantially reduces the overhead of profiling,
1286 but it is still quite preliminary. Support modules and
1287 documentation will be added in upcoming releases (before 2.2 final).
1288
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001289- profile now produces correct output in situations where an exception
1290 raised in Python is cleared by C code (e.g. hasattr()). This used
1291 to cause wrong output, including spurious claims of recursive
1292 functions and attribution of time spent to the wrong function.
1293
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001294 The code and documentation for the derived OldProfile and HotProfile
1295 profiling classes was removed. The code hasn't worked for years (if
1296 you tried to use them, they raised exceptions). OldProfile
1297 intended to reproduce the behavior of the profiler Python used more
1298 than 7 years ago, and isn't interesting anymore. HotProfile intended
1299 to provide a faster profiler (but producing less information), and
1300 that's a worthy goal we intend to meet via a different approach (but
1301 without losing information).
1302
Tim Peterscce092d2001-10-09 05:31:56 +00001303- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001304 a much better system-specific calibration constant. The constant can
1305 now be specified in an instance constructor, or as a Profile class or
1306 instance variable, instead of by editing profile.py's source code.
1307 Calibration must still be done manually (see the docs for the profile
1308 module).
1309
1310 Note that Profile.calibrate() must be overriden by subclasses.
1311 Improving the accuracy required exploiting detailed knowledge of
1312 profiler internals; the earlier method abstracted away the details
1313 and measured a simplified model instead, but consequently computed
1314 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001315
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001316- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001317 which indicates whether output is intended for the header 'Q'
1318 encoding.
1319
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001320- The SocketServer.ThreadingMixIn class now closes the request after
1321 finish_request() returns. (Not when it errors out though.)
1322
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001323- The nntplib module's NNTP.body() method has grown a 'file' argument
Barry Warsawf6fb1712001-10-19 05:35:40 +00001324 to allow saving the message body to a file.
1325
1326- The email package has added a class email.Parser.HeaderParser which
1327 only parses headers and does not recurse into the message's body.
1328 Also, the module/class MIMEAudio has been added for representing
1329 audio data (contributed by Anthony Baxter).
1330
1331- ftplib should be able to handle files > 2GB.
1332
1333- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1334 ON, and OFF.
1335
Fred Drakecb7a6b52001-10-22 18:41:51 +00001336- xml.dom.minidom NodeList objects now support the length attribute
1337 and item() method as required by the DOM specifications.
1338
Guido van Rossumed554f62001-10-02 23:15:37 +00001339Tools/Demos
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001340-----------
Guido van Rossumed554f62001-10-02 23:15:37 +00001341
1342- Demo/dns was removed. It no longer serves any purpose; a package
1343 derived from it is now maintained by Anthony Baxter, see
1344 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001345
Barry Warsawf6fb1712001-10-19 05:35:40 +00001346- The freeze tool has been made more robust, and two new options have
1347 been added: -X and -E.
1348
Tim Petersabf925f2001-09-28 21:53:42 +00001349Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001350-----
Tim Petersabf925f2001-09-28 21:53:42 +00001351
Barry Warsawf6fb1712001-10-19 05:35:40 +00001352- configure will use CXX in LINKCC if CXX is used to build main() and
1353 the system requires to link a C++ main using the C++ compiler.
1354
Tim Petersabf925f2001-09-28 21:53:42 +00001355C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001356-----
Tim Petersabf925f2001-09-28 21:53:42 +00001357
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001358- The documentation for the tp_compare slot is updated to require that
1359 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1360 not correct. This is not yet enforced but will be enforced in
1361 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1362 "NotImplemented". Right now, -1 should be used for an error return.
1363
Tim Petersd38b1c72001-09-30 05:09:37 +00001364- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1365 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1366 as long) arguments.
1367
Guido van Rossum3c288632001-10-16 21:13:49 +00001368- PyThread_start_new_thread() now returns a long int giving the thread
1369 ID, if one can be calculated; it returns -1 for error, 0 if no
1370 thread ID is calculated (this is an incompatible change, but only
1371 the thread module used this API). This code has only really been
1372 tested on Linux and Windows; other platforms please beware (and
1373 report any bugs or strange behavior).
1374
Guido van Rossum1c486092001-10-19 02:05:35 +00001375- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1376 input.
1377
Tim Petersabf925f2001-09-28 21:53:42 +00001378New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001379-------------
Tim Petersabf925f2001-09-28 21:53:42 +00001380
1381Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001382-----
Tim Petersabf925f2001-09-28 21:53:42 +00001383
1384Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001385-------
Tim Petersabf925f2001-09-28 21:53:42 +00001386
Tim Peters04cf1d32001-10-09 22:39:40 +00001387- Installer: If you install IDLE, and don't disable file-extension
1388 registration, a new "Edit with IDLE" context (right-click) menu entry
1389 is created for .py and .pyw files.
1390
Tim Peters1ce3cf72001-10-01 17:58:40 +00001391- The signal module now supports SIGBREAK on Windows, thanks to Steven
1392 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1393 action remains to call Win32 ExitProcess(). This can be changed via
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001394 signal.signal(). For example::
Tim Peters1ce3cf72001-10-01 17:58:40 +00001395
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001396 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1397 # (SIGINT) behavior.
1398 import signal
1399 signal.signal(signal.SIGBREAK, signal.default_int_handler)
Tim Peters1ce3cf72001-10-01 17:58:40 +00001400
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001401 try:
1402 while 1:
1403 pass
1404 except KeyboardInterrupt:
1405 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1406 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1407 # program without the possibility for any Python-level cleanup).
1408 print "Clean exit"
Tim Peters1ce3cf72001-10-01 17:58:40 +00001409
Tim Petersabf925f2001-09-28 21:53:42 +00001410
Tim Petersb07352e2001-09-08 01:25:47 +00001411What's New in Python 2.2a4?
1412===========================
1413
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001414*Release date: 28-Sep-2001*
1415
Guido van Rossum808eea72001-09-25 04:15:41 +00001416Type/class unification and new-style classes
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001417--------------------------------------------
Guido van Rossum808eea72001-09-25 04:15:41 +00001418
1419- pydoc and inspect are now aware of new-style classes;
1420 e.g. help(list) at the interactive prompt now shows proper
1421 documentation for all operations on list objects.
1422
1423- Applications using Jim Fulton's ExtensionClass module can now safely
1424 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1425 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1426 examples also work again. It is hoped that Gtk and Boost also work
1427 with 2.2a4 and beyond. (If you can confirm this, please write
1428 webmaster@python.org; if there are still problems, please open a bug
1429 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001430
Tim Peters66c1a522001-09-24 21:17:50 +00001431- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001432 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001433 in the constructed property object. fget, fset and fdel weren't
1434 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1435 associate a docstring with a property.
1436
Guido van Rossum808eea72001-09-25 04:15:41 +00001437- Comparison overloading is now more completely implemented. For
1438 example, a str subclass instance can properly be compared to a str
1439 instance, and it can properly overload comparison. Ditto for most
1440 other built-in object types.
1441
1442- The repr() of new-style classes has changed; instead of <type
1443 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1444 *except* for built-in types, which are still rendered as <type
1445 'Foo'> (to avoid upsetting existing code that might parse or
1446 otherwise rely on repr() of certain type objects).
1447
1448- The repr() of new-style objects is now always <Foo object at XXX>;
1449 previously, it was sometimes <Foo instance at XXX>.
1450
1451- For new-style classes, what was previously called __getattr__ is now
1452 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001453 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001454 one in classic classes is defined which is called only if regular
1455 attribute access raises AttributeError; to catch *all* attribute
1456 access, you can use __getattribute__ (for new-style classes). If
1457 both are defined, __getattribute__ is called first, and if it raises
1458 AttributeError, __getattr__ is called.
1459
1460- The __class__ attribute of new-style objects can be assigned to.
1461 The new class must have the same C-level object layout as the old
1462 class.
1463
1464- The builtin file type can be subclassed now. In the usual pattern,
1465 "file" is the name of the builtin type, and file() is a new builtin
1466 constructor, with the same signature as the builtin open() function.
1467 file() is now the preferred way to open a file.
1468
1469- Previously, __new__ would only see sequential arguments passed to
1470 the type in a constructor call; __init__ would see both sequential
1471 and keyword arguments. This made no sense whatsoever any more, so
1472 now both __new__ and __init__ see all arguments.
1473
1474- Previously, hash() applied to an instance of a subclass of str or
1475 unicode always returned 0. This has been repaired.
1476
1477- Previously, an operation on an instance of a subclass of an
1478 immutable type (int, long, float, complex, tuple, str, unicode),
1479 where the subtype didn't override the operation (and so the
1480 operation was handled by the builtin type), could return that
1481 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001482 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001483 with the same value as s.
1484
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001485- Provisional support for pickling new-style objects has been added.
1486
Guido van Rossum808eea72001-09-25 04:15:41 +00001487Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001488----
Guido van Rossum808eea72001-09-25 04:15:41 +00001489
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001490- file.writelines() now accepts any iterable object producing strings.
1491
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001492- PyUnicode_FromEncodedObject() now works very much like
1493 PyObject_Str(obj) in that it tries to use __str__/tp_str
1494 on the object if the object is not a string or buffer. This
1495 makes unicode() behave like str() when applied to non-string/buffer
1496 objects.
1497
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001498- PyFile_WriteObject now passes Unicode objects to the file's write
1499 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001500 of a print statement must support Unicode objects, i.e. they must
1501 at least convert them into ASCII strings.
1502
Guido van Rossum624c8af2001-09-18 15:21:04 +00001503- Thread scheduling on Solaris should be improved; it is no longer
1504 necessary to insert a small sleep at the start of a thread in order
1505 to let other runnable threads be scheduled.
1506
Tim Petersb07352e2001-09-08 01:25:47 +00001507Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001508-------
Tim Petersb07352e2001-09-08 01:25:47 +00001509
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001510- StringIO.StringIO instances and cStringIO.StringIO instances support
1511 read character buffer compatible objects for their .write() methods.
1512 These objects are converted to strings and then handled as such
1513 by the instances.
1514
Barry Warsaw2f600732001-09-24 04:28:10 +00001515- The "email" package has been added. This is basically a port of the
1516 mimelib package <http://sf.net/projects/mimelib> with API changes
1517 and some implementations updated to use iterators and generators.
1518
Tim Peters8a9c2842001-09-22 21:30:22 +00001519- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1520 restores the ability of Tools/scripts/ndiff.py to start producing output
1521 before the entire comparison is complete.
1522
Barry Warsaw58b072d2001-09-22 04:44:21 +00001523- StringIO.StringIO instances and cStringIO.StringIO instances support
1524 iteration just like file objects (i.e. their .readline() method is
1525 called for each iteration until it returns an empty string).
1526
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001527- The codecs module has grown four new helper APIs to access
1528 builtin codecs: getencoder(), getdecoder(), getreader(),
1529 getwriter().
1530
Guido van Rossum624c8af2001-09-18 15:21:04 +00001531- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1532 simplifies writing XML RPC servers.
1533
Barry Warsaw647d5e82001-09-28 17:01:02 +00001534- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001535 after interpretation of symbolic links. On non-Unix systems, this
1536 is an alias for os.path.abspath().
1537
Tim Peters16a77ad2001-09-08 04:00:12 +00001538- operator.indexOf() (PySequence_Index() in the C API) now works with any
1539 iterable object.
1540
Guido van Rossum624c8af2001-09-18 15:21:04 +00001541- smtplib now supports various authentication and security features of
1542 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001543
Guido van Rossum624c8af2001-09-18 15:21:04 +00001544- hmac: a new module implementing keyed hashing for message
1545 authentication.
1546
1547- mimetypes now recognizes more extensions and file types. At the
1548 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001549
Guido van Rossum624c8af2001-09-18 15:21:04 +00001550- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001551 Python 2.2 bytecode generation. It has also been promoted from a
1552 Tool to a standard library package. (Tools/compiler still exists as
1553 a sample driver.)
1554
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001555Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001556-----
Guido van Rossum624c8af2001-09-18 15:21:04 +00001557
Tim Petersb07352e2001-09-08 01:25:47 +00001558Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001559-----
Tim Petersb07352e2001-09-08 01:25:47 +00001560
Guido van Rossum624c8af2001-09-18 15:21:04 +00001561- Large file support (LFS) is now automatic when the platform supports
1562 it; no more manual configuration tweaks are needed. On Linux, at
1563 least, it's possible to have a system whose C library supports large
1564 files but whose kernel doesn't; in this case, large file support is
1565 still enabled but doesn't do you any good unless you upgrade your
1566 kernel or share your Python executable with another system whose
1567 kernel has large file support.
1568
1569- The configure script now supplies plausible defaults in a
1570 cross-compilation environment. This doesn't mean that the supplied
1571 values are always correct, or that cross-compilation now works
1572 flawlessly -- but it's a first step (and it shuts up most of
1573 autoconf's warnings about AC_TRY_RUN).
1574
1575- The Unix build is now a bit less chatty, courtesy of the parser
1576 generator. The build is completely silent (except for errors) when
1577 using "make -s", thanks to a -q option to setup.py.
1578
Tim Petersb07352e2001-09-08 01:25:47 +00001579C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001580-----
Tim Petersb07352e2001-09-08 01:25:47 +00001581
Guido van Rossum624c8af2001-09-18 15:21:04 +00001582- The "structmember" API now supports some new flag bits to deny read
1583 and/or write access to attributes in restricted execution mode.
1584
Tim Petersb07352e2001-09-08 01:25:47 +00001585New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001586-------------
Tim Petersb07352e2001-09-08 01:25:47 +00001587
Guido van Rossum624c8af2001-09-18 15:21:04 +00001588- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1589 (http://familiar.handhelds.org).
1590
Tim Petersb07352e2001-09-08 01:25:47 +00001591Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001592-----
Tim Petersb07352e2001-09-08 01:25:47 +00001593
Tim Peters8a9c2842001-09-22 21:30:22 +00001594- The "classic" standard tests, which work by comparing stdout to
1595 an expected-output file under Lib/test/output/, no longer stop at
1596 the first mismatch. Instead the test is run to completion, and a
1597 variant of ndiff-style comparison is used to report all differences.
1598 This is much easier to understand than the previous style of reporting.
1599
1600- The unittest-based standard tests now use regrtest's test_main()
1601 convention, instead of running as a side-effect of merely being
1602 imported. This allows these tests to be run in more natural and
1603 flexible ways as unittests, outside the regrtest framework.
1604
1605- regrtest.py is much better integrated with unittest and doctest now,
1606 especially in regard to reporting errors.
1607
Tim Petersb07352e2001-09-08 01:25:47 +00001608Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001609-------
Tim Petersb07352e2001-09-08 01:25:47 +00001610
Guido van Rossum624c8af2001-09-18 15:21:04 +00001611- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001612 that support it (NTFS under Windows 2000). See "What's New in
1613 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001614
Tim Petersb07352e2001-09-08 01:25:47 +00001615
Tim Petersedc99312001-08-22 21:36:50 +00001616What's New in Python 2.2a3?
1617===========================
1618
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001619*Release Date: 07-Sep-2001*
1620
Tim Petersedc99312001-08-22 21:36:50 +00001621Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001622----
Tim Petersedc99312001-08-22 21:36:50 +00001623
Tim Peters9fffa3e2001-09-04 05:14:19 +00001624- Conversion of long to float now raises OverflowError if the long is too
1625 big to represent as a C double.
1626
Tim Peters32f453e2001-09-03 08:35:41 +00001627- The 3-argument builtin pow() no longer allows a third non-None argument
1628 if either of the first two arguments is a float, or if both are of
1629 integer types and the second argument is negative (in which latter case
1630 the arguments are converted to float, so this is really the same
1631 restriction).
1632
Tim Peters5d2b77c2001-09-03 05:47:38 +00001633- The builtin dir() now returns more information, and sometimes much
1634 more, generally naming all attributes of an object, and all attributes
1635 reachable from the object via its class, and from its class's base
1636 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1637 an empty list. In 2.2a3,
1638
1639 >>> dir([])
1640 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1641 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1642 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1643 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1644 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1645 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1646 'reverse', 'sort']
1647
1648 dir(module) continues to return only the module's attributes, though.
1649
Tim Petersbdee63f2001-09-02 03:40:59 +00001650- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001651 than raising OverflowError. This is a partial implementation of PEP
1652 237. You can use -Wdefault::OverflowWarning to enable a warning for
1653 this situation, and -Werror::OverflowWarning to revert to the old
1654 OverflowError exception.
1655
Guido van Rossum61c345f2001-09-04 03:26:15 +00001656- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001657 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001658 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1659 -Qold, meaning the / operator has its classic meaning and no
1660 warnings are issued. Using -Qwarn issues a run-time warning about
1661 all uses of classic division for int and long arguments; -Qwarnall
1662 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001663 (for use with fixdiv.py).
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001664 [Note: the remainder of this item (preserved below) became
1665 obsolete in 2.2c1 -- -Qnew has global effect in 2.2] ::
1666
1667 Using -Qnew is questionable; it turns on new division by default, but
1668 only in the __main__ module. You can usefully combine -Qwarn or
1669 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1670 warns about classic division everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +00001671
Tim Petersbdee63f2001-09-02 03:40:59 +00001672- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001673 long, float, str, unicode, and tuple. (The types complex, list and
1674 dictionary can also be subclassed; this was introduced earlier.)
1675 Note that restrictions apply when subclassing immutable built-in
1676 types: you can only affect the value of the instance by overloading
1677 __new__. You can add mutable attributes, and the subclass instances
1678 will have a __dict__ attribute, but you cannot change the "value"
1679 (as implemented by the base class) of an immutable subclass instance
1680 once it is created.
1681
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001682- The dictionary constructor now takes an optional argument, a
1683 mapping-like object, and initializes the dictionary from its
1684 (key, value) pairs.
1685
Tim Petersbdee63f2001-09-02 03:40:59 +00001686- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001687 "cooperative super calls" in a multiple inheritance setting. For an
1688 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1689
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001690- A new built-in type, property, has been added. This enables the
1691 creation of "properties". These are attributes implemented by
1692 getter and setter functions (or only one of these for read-only or
1693 write-only attributes), without the need to override __getattr__.
1694 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001695
Tim Petersbdee63f2001-09-02 03:40:59 +00001696- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001697 liberalized, to allow leading zeroes. Examples of literals now
1698 legal that were SyntaxErrors before:
1699
1700 00.0 0e3 0100j 07.5 00000000000000000008.
1701
Tim Petersbdee63f2001-09-02 03:40:59 +00001702- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001703 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1704
Tim Petersedc99312001-08-22 21:36:50 +00001705Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001706-------
Tim Petersedc99312001-08-22 21:36:50 +00001707
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001708- telnetlib includes symbolic names for the options, and support for
1709 setting an option negotiation callback.
1710
Tim Petersa40c7932001-09-05 22:36:56 +00001711- The new C standard no longer requires that math libraries set errno to
1712 ERANGE on overflow. For platform libraries that exploit this new
1713 freedom, Python's overflow-checking was wholly broken. A new overflow-
1714 checking scheme attempts to repair that, but may not be reliable on all
1715 platforms (C doesn't seem to provide anything both useful and portable
1716 in this area anymore).
1717
Martin v. Löwis44f86962001-09-05 13:44:54 +00001718- Asynchronous timeout actions are available through the new class
1719 threading.Timer.
1720
Tim Peters78526162001-09-05 00:53:45 +00001721- math.log and math.log10 now return sensible results for even huge
1722 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1723
Tim Petersbdee63f2001-09-02 03:40:59 +00001724- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001725 currently held. See the docs for the imp module.
1726
Tim Petersbdee63f2001-09-02 03:40:59 +00001727- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001728 dumps containing ints written on platforms where Python ints are 8 bytes.
1729 When read on a box where Python ints are 4 bytes, such values are
1730 converted to Python longs.
1731
Tim Petersbdee63f2001-09-02 03:40:59 +00001732- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001733 code objects is no longer allowed. This plugs a security hole.
1734
Steve Purcell6091cd62001-09-06 16:05:17 +00001735- unittest.TestResult instances no longer store references to tracebacks
1736 generated by test failures. This prevents unexpected dangling references
1737 to objects that should be garbage collected between tests.
1738
Tim Petersedc99312001-08-22 21:36:50 +00001739Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001740-----
Tim Petersedc99312001-08-22 21:36:50 +00001741
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001742- Tools/scripts/fixdiv.py has been added which can be used to fix
1743 division operators as per PEP 238.
1744
Tim Petersedc99312001-08-22 21:36:50 +00001745Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001746-----
Tim Petersedc99312001-08-22 21:36:50 +00001747
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001748- If you are an adventurous person using Mac OS X you may want to look at
1749 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1750 application, which can be used for experimenting with Carbon or Cocoa.
1751 Discussion of this on pythonmac-sig, please.
1752
Tim Peters7eea37e2001-09-04 22:08:56 +00001753C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001754-----
Tim Peters7eea37e2001-09-04 22:08:56 +00001755
1756- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001757
Tim Peters9fffa3e2001-09-04 05:14:19 +00001758- Note that PyLong_AsDouble can fail! This has always been true, but no
1759 callers checked for it. It's more likely to fail now, because overflow
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00001760 errors are properly detected now. The proper way to check::
Tim Peters9fffa3e2001-09-04 05:14:19 +00001761
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001762 double x = PyLong_AsDouble(some_long_object);
1763 if (x == -1.0 && PyErr_Occurred()) {
1764 /* The conversion failed. */
1765 }
Tim Peters9fffa3e2001-09-04 05:14:19 +00001766
Tim Petersbdee63f2001-09-02 03:40:59 +00001767- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001768 compile but will not participate in GC. To upgrade an extension
1769 module:
1770
1771 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001772
Neil Schemenauer4042c692001-08-30 15:38:01 +00001773 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1774 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001775
Neil Schemenauer4042c692001-08-30 15:38:01 +00001776 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1777 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001778
Neil Schemenauer4042c692001-08-30 15:38:01 +00001779 - remove PyGC_HEAD_SIZE from object size calculations
1780
1781 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1782
Tim Petersbdee63f2001-09-02 03:40:59 +00001783- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001784 These can be used safely to construct string objects from a
1785 sprintf-style format string (similar to the format string supported
1786 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001787
Tim Petersedc99312001-08-22 21:36:50 +00001788New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001789-------------
Tim Petersedc99312001-08-22 21:36:50 +00001790
Tim Petersb7da0902001-09-02 23:01:43 +00001791- Stephen Hansen contributed patches sufficient to get a clean compile
1792 under Borland C (Windows), but he reports problems running it and ran
1793 out of time to complete the port. Volunteers? Expect a MemoryError
1794 when importing the types module; this is probably shallow, and
1795 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001796
Tim Petersedc99312001-08-22 21:36:50 +00001797Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001798-----
Tim Petersedc99312001-08-22 21:36:50 +00001799
1800Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001801-------
Tim Petersedc99312001-08-22 21:36:50 +00001802
Tim Peters6e13a562001-09-06 00:32:15 +00001803- Large file support is now enabled on Win32 platforms as well as on
1804 Win64. This means that, for example, you can use f.tell() and f.seek()
1805 to manipulate files larger than 2 gigabytes (provided you have enough
1806 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001807 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1808 filesize limit, and large file support makes no difference there.
1809 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1810 NTFS has no practical limit on file size, and files of any size can be
1811 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001812
Tim Petersbdee63f2001-09-02 03:40:59 +00001813- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001814 points to command.com (patch from Brian Quinlan).
1815
Tim Petersedc99312001-08-22 21:36:50 +00001816
Tim Peters20f51a72001-07-21 02:31:40 +00001817What's New in Python 2.2a2?
1818===========================
1819
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001820*Release Date: 22-Aug-2001*
1821
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001822Build
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001823-----
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001824
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001825- Tim Peters developed a brand new Windows installer using Wise 8.1,
1826 generously donated to us by Wise Solutions.
1827
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001828- configure supports a new option --enable-unicode, with the values
1829 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1830 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001831
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001832- A new configure option --enable-framework builds a Mac OS X framework,
1833 which "make frameworkinstall" will install. This provides a starting
1834 point for more mac-like functionality, join pythonmac-sig@python.org
1835 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001836
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001837- The NeXT platform is no longer supported.
1838
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001839- The 'new' module is now statically linked.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001840
Tim Peters0afb6092001-08-15 06:06:44 +00001841Tools
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001842-----
Tim Peters0afb6092001-08-15 06:06:44 +00001843
1844- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001845 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001846 the module docstring for details.
1847
Tim Peters20f51a72001-07-21 02:31:40 +00001848Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001849-----
Tim Peters20f51a72001-07-21 02:31:40 +00001850
Tim Peters5e824c32001-08-12 22:25:01 +00001851- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001852 platforms, allowing to give clearer test result output. regrtest
1853 also has optional --use/-u switch to run normally disabled tests
1854 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001855
Tim Peters20f51a72001-07-21 02:31:40 +00001856- Several new tests in the standard test suite, with special thanks to
1857 Nick Mathewson.
1858
1859Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001860----
Tim Peters20f51a72001-07-21 02:31:40 +00001861
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001862- The floor division operator // has been added as outlined in PEP
1863 238. The / operator still provides classic division (and will until
1864 Python 3.0) unless "from __future__ import division" is included, in
1865 which case the / operator will provide true division. The operator
1866 module provides truediv() and floordiv() functions. Augmented
1867 assignment variants are included, as are the equivalent overloadable
1868 methods and C API methods. See the PEP for a full discussion:
1869 <http://python.sf.net/peps/pep-0238.html>
1870
Tim Peters6cd6a822001-08-17 22:11:27 +00001871- Future statements are now effective in simulated interactive shells
1872 (like IDLE). This should "just work" by magic, but read Michael
1873 Hudson's "Future statements in simulated shells" PEP 264 for full
1874 details: <http://python.sf.net/peps/pep-0264.html>.
1875
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001876- The type/class unification (PEP 252-253) was integrated into the
1877 trunk and is not so tentative any more (the exact specification of
1878 some features is still tentative). A lot of work has done on fixing
1879 bugs and adding robustness and features (performance still has to
1880 come a long way).
1881
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001882- Warnings about a mismatch in the Python API during extension import
1883 now use the Python warning framework (which makes it possible to
1884 write filters for these warnings).
1885
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001886- A function's __dict__ (aka func_dict) will now always be a
1887 dictionary. It used to be possible to delete it or set it to None,
1888 but now both actions raise TypeErrors. It is still legal to set it
1889 to a dictionary object. Getting func.__dict__ before any attributes
1890 have been assigned now returns an empty dictionary instead of None.
1891
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001892- A new command line option, -E, was added which disables the use of
1893 all environment variables, or at least those that are specifically
1894 significant to Python. Usually those have a name starting with
1895 "PYTHON". This was used to fix a problem where the tests fail if
1896 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1897 older distribution.
1898
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001899Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001900-------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001901
Tim Peters5e824c32001-08-12 22:25:01 +00001902- New class Differ and new functions ndiff() and restore() in difflib.py.
1903 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001904 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001905
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001906- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1907 value using the minimal quoting required for the value; more
1908 reliable than using xml.sax.saxutils.escape() for attribute values.
1909
1910- Readline completion support for cmd.Cmd was added.
1911
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001912- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1913
1914- Added function threading.BoundedSemaphore()
1915
1916- Added Ka-Ping Yee's cgitb.py module.
1917
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001918- The 'new' module now exposes the CO_xxx flags.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001919
Martin v. Löwis560da622001-11-24 09:24:51 +00001920- The gc module offers the get_referents function.
1921
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001922New platforms
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001923-------------
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001924
1925C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001926-----
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001927
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001928- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1929 which provide a cross-platform implementations for the
1930 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1931 the standard sprintf() and vsprintf() C lib APIs, these versions
1932 apply bounds checking on the used buffer which enhances protection
1933 against buffer overruns.
1934
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001935- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001936 and extensions using different Unicode widths is rendered next to
1937 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001938 will result in an ImportError. Unicode extensions writers must make
1939 sure to check the Unicode width compatibility in their extensions by
1940 using at least one of the mangled Unicode APIs in the extension.
1941
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001942- Two new flags METH_NOARGS and METH_O are available in method definition
1943 tables to simplify implementation of methods with no arguments and a
1944 single untyped argument. Calling such methods is more efficient than
1945 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1946 deprecated.
1947
Tim Petersc1731372001-08-04 08:12:36 +00001948Windows
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001949-------
Tim Petersc1731372001-08-04 08:12:36 +00001950
1951- "import module" now compiles module.pyw if it exists and nothing else
1952 relevant is found.
1953
Tim Peters20f51a72001-07-21 02:31:40 +00001954
Guido van Rossum55a78992001-07-17 17:22:32 +00001955What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +00001956===========================
1957
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001958*Release date: 18-Jul-2001*
1959
Tim Petersf553f892001-05-01 20:45:31 +00001960Core
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00001961----
Tim Petersa814db52001-05-14 07:05:58 +00001962
Tim Peters6d6c1a32001-08-02 04:15:00 +00001963- TENTATIVELY, a large amount of code implementing much of what's
1964 described in PEP 252 (Making Types Look More Like Classes) and PEP
1965 253 (Subtyping Built-in Types) was added. This will be released
1966 with Python 2.2a1. Documentation will be provided separately
1967 through http://www.python.org/2.2/. The purpose of releasing this
1968 with Python 2.2a1 is to test backwards compatibility. It is
1969 possible, though not likely, that a decision is made not to release
1970 this code as part of 2.2 final, if any serious backwards
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00001971 incompatibilities are found during alpha testing that cannot be
Tim Peters6d6c1a32001-08-02 04:15:00 +00001972 repaired.
1973
Guido van Rossum55a78992001-07-17 17:22:32 +00001974- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001975 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001976 more 'yield' statements. See PEP 255. Since this adds a new
1977 keyword to the language, this feature must be enabled by including a
1978 future statement: "from __future__ import generators" (see PEP 236).
1979 Generators will become a standard feature in a future release
1980 (probably 2.3). Without this future statement, 'yield' remains an
1981 ordinary identifier, but a warning is issued each time it is used.
1982 (These warnings currently don't conform to the warnings framework of
1983 PEP 230; we intend to fix this in 2.2a2.)
1984
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001985- The UTF-16 codec was modified to be more RFC compliant. It will now
1986 only remove BOM characters at the start of the string and then
1987 only if running in native mode (UTF-16-LE and -BE won't remove a
1988 leading BMO character).
1989
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001990- Strings now have a new method .decode() to complement the already
1991 existing .encode() method. These two methods provide direct access
1992 to the corresponding decoders and encoders of the registered codecs.
1993
1994 To enhance the usability of the .encode() method, the special
1995 casing of Unicode object return values was dropped (Unicode objects
1996 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001997
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001998 Both methods will now return whatever the codec in charge of the
1999 requested encoding returns as object, e.g. Unicode codecs will
2000 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
2001 will return u"äöü"). This enables codec writer to create codecs
2002 for various simple to use conversions.
2003
2004 New codecs were added to demonstrate these new features (the .encode()
2005 and .decode() columns indicate the type of the returned objects):
2006
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002007 +---------+-----------+-----------+-----------------------------+
2008 |Name | .encode() | .decode() | Description |
2009 +=========+===========+===========+=============================+
2010 |uu | string | string | UU codec (e.g. for email) |
2011 +---------+-----------+-----------+-----------------------------+
2012 |base64 | string | string | base64 codec |
2013 +---------+-----------+-----------+-----------------------------+
2014 |quopri | string | string | quoted-printable codec |
2015 +---------+-----------+-----------+-----------------------------+
2016 |zlib | string | string | zlib compression |
2017 +---------+-----------+-----------+-----------------------------+
2018 |hex | string | string | 2-byte hex codec |
2019 +---------+-----------+-----------+-----------------------------+
2020 |rot-13 | string | Unicode | ROT-13 Unicode charmap codec|
2021 +---------+-----------+-----------+-----------------------------+
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00002022
Mark Hammond2a0af792001-05-14 03:09:36 +00002023- Some operating systems now support the concept of a default Unicode
2024 encoding for file system operations. Notably, Windows supports 'mbcs'
2025 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00002026 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00002027 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00002028
2029 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00002030 functions that return filenames (such as os.listdir()) to return Python
2031 string objects pre-encoded using the default file system encoding for
2032 the platform. As this encoding is likely to be different from Python's
2033 default encoding, converting this name to a Unicode object before passing
2034 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00002035 would attempt to use its default encoding (generally ASCII) rather than
2036 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00002037
Tim Petersa814db52001-05-14 07:05:58 +00002038 In general, this change simply removes surprises when working with
2039 Unicode and the file system, making these operations work as you expect,
2040 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00002041 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00002042
Tim Peters61dff2b2001-05-08 15:43:37 +00002043- Float (and complex) literals in source code were evaluated to full
2044 precision only when running from a .py file; the same code loaded from a
2045 .pyc (or .pyo) file could suffer numeric differences starting at about the
2046 12th significant decimal digit. For example, on a machine with IEEE-754
2047 floating arithmetic,
2048
2049 x = 9007199254740992.0
2050 print long(x)
2051
2052 printed 9007199254740992 if run directly from .py, but 9007199254740000
2053 if from a compiled (.pyc or .pyo) file. This was due to marshal using
2054 str(float) instead of repr(float) when building code objects. marshal
2055 now uses repr(float) instead, which should reproduce floats to full
2056 machine precision (assuming the platform C float<->string I/O conversion
2057 functions are of good quality).
2058
2059 This may cause floating-point results to change in some cases, and
2060 usually for the better, but may also cause numerically unstable
2061 algorithms to break.
2062
Tim Peters2f228e72001-05-13 00:19:31 +00002063- The implementation of dicts suffers fewer collisions, which has speed
2064 benefits. However, the order in which dict entries appear in dict.keys(),
2065 dict.values() and dict.items() may differ from previous releases for a
2066 given dict. Nothing is defined about this order, so no program should
2067 rely on it. Nevertheless, it's easy to write test cases that rely on the
2068 order by accident, typically because of printing the str() or repr() of a
2069 dict to an "expected results" file. See Lib/test/test_support.py's new
2070 sortdict(dict) function for a simple way to display a dict in sorted
2071 order.
2072
Tim Peters7a3bfc32001-06-12 01:22:22 +00002073- Many other small changes to dicts were made, resulting in faster
2074 operation along the most common code paths.
2075
Guido van Rossum10315822001-05-01 20:54:30 +00002076- Dictionary objects now support the "in" operator: "x in dict" means
2077 the same as dict.has_key(x).
2078
Barry Warsaw51acc8d2001-06-26 20:12:50 +00002079- The update() method of dictionaries now accepts generic mapping
2080 objects. Specifically the argument object must support the .keys()
2081 and __getitem__() methods. This allows you to say, for example,
2082 {}.update(UserDict())
2083
Guido van Rossum10315822001-05-01 20:54:30 +00002084- Iterators were added; this is a generalized way of providing values
2085 to a for loop. See PEP 234. There's a new built-in function iter()
2086 to return an iterator. There's a new protocol to get the next value
2087 from an iterator using the next() method (in Python) or the
2088 tp_iternext slot (in C). There's a new protocol to get iterators
2089 using the __iter__() method (in Python) or the tp_iter slot (in C).
2090 Iterating (i.e. a for loop) over a dictionary generates its keys.
2091 Iterating over a file generates its lines.
2092
Tim Petersf553f892001-05-01 20:45:31 +00002093- The following functions were generalized to work nicely with iterator
Skip Montanaroa2a07bc2002-09-30 15:23:01 +00002094 arguments::
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002095
Tim Peterse63415e2001-05-08 04:38:29 +00002096 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00002097 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
2098 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00002099 join() method of strings
2100 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00002101 'x in y' and 'x not in y' (PySequence_Contains() in C API)
2102 operator.countOf() (PySequence_Count() in C API)
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002103 right-hand side of assignment statements with multiple targets, such as ::
Tim Petersd6d010b2001-06-21 02:49:55 +00002104 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00002105
Tim Petersd85e1022001-05-11 21:51:48 +00002106- Accessing module attributes is significantly faster (for example,
2107 random.random or os.path or yourPythonModule.yourAttribute).
2108
Tim Peterse63415e2001-05-08 04:38:29 +00002109- Comparing dictionary objects via == and != is faster, and now works even
2110 if the keys and values don't support comparisons other than ==.
2111
Tim Peters95bf9392001-05-10 08:32:44 +00002112- Comparing dictionaries in ways other than == and != is slower: there were
2113 insecurities in the dict comparison implementation that could cause Python
2114 to crash if the element comparison routines for the dict keys and/or
2115 values mutated the dicts. Making the code bulletproof slowed it down.
2116
Tim Peterseb28ef22001-06-02 05:27:19 +00002117- Collisions in dicts are resolved via a new approach, which can help
2118 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00002119 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00002120 faster now. Thanks to Christian Tismer for pointing out the cause and
2121 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00002122
Tim Peters52e155e2001-06-16 05:42:57 +00002123- repr() is much faster for large containers (dict, list, tuple).
2124
2125
Tim Petersa814db52001-05-14 07:05:58 +00002126Library
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002127-------
Tim Petersa814db52001-05-14 07:05:58 +00002128
Fred Drake960fdf92001-07-20 18:38:26 +00002129- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002130 were added to the string module. These a locale-independent
Fred Drake960fdf92001-07-20 18:38:26 +00002131 constants, unlike letters, lowercase, and uppercase. These are now
2132 use in appropriate locations in the standard library.
2133
Martin v. Löwisf0473d52001-07-18 16:17:16 +00002134- The flags used in dlopen calls can now be configured using
2135 sys.setdlopenflags and queried using sys.getdlopenflags.
2136
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00002137- Fredrik Lundh's xmlrpclib is now a standard library module. This
2138 provides full client-side XML-RPC support. In addition,
2139 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
2140 one asyncore-based). Thanks to Eric Raymond for the documentation.
2141
Guido van Rossum643d3912001-07-05 14:46:25 +00002142- The xrange() object is simplified: it no longer supports slicing,
2143 repetition, comparisons, efficient 'in' checking, the tolist()
2144 method, or the start, stop and step attributes. See PEP 260.
2145
Martin v. Löwisebf94db2001-06-06 06:25:40 +00002146- A new function fnmatch.filter to filter lists of file names was added.
2147
Barry Warsawffd674d2001-05-22 16:00:10 +00002148- calendar.py uses month and day names based on the current locale.
2149
Guido van Rossum2e0a6542001-05-15 02:14:44 +00002150- strop is now *really* obsolete (this was announced before with 1.6),
2151 and issues DeprecationWarning when used (except for the four items
2152 that are still imported into string.py).
2153
Tim Petersa814db52001-05-14 07:05:58 +00002154- Cookie.py now sorts key+value pairs by key in output strings.
2155
2156- pprint.isrecursive(object) didn't correctly identify recursive objects.
2157 Now it does.
2158
Tim Peters95b3f782001-05-14 18:39:41 +00002159- pprint functions now much faster for large containers (tuple, list, dict).
2160
Tim Peters7b9542a2001-06-10 23:40:19 +00002161- New 'q' and 'Q' format codes in the struct module, corresponding to C
2162 types "long long" and "unsigned long long" (on Windows, __int64). In
2163 native mode, these can be used only when the platform C compiler supports
2164 these types (when HAVE_LONG_LONG is #define'd by the Python config
2165 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00002166 In standard mode, 'q' and 'Q' are supported on all platforms, and are
2167 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00002168
Guido van Rossum83213cc2001-06-12 16:48:52 +00002169- The site module installs a new built-in function 'help' that invokes
2170 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
2171 it displays a message reminding the user to use 'help()' or
2172 'help(object)'.
2173
Tim Petersa814db52001-05-14 07:05:58 +00002174Tests
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002175-----
Tim Petersa814db52001-05-14 07:05:58 +00002176
2177- New test_mutants.py runs dict comparisons where the key and value
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002178 comparison operators mutate the dicts randomly during comparison. This
Tim Petersa814db52001-05-14 07:05:58 +00002179 rapidly causes Python to crash under earlier releases (not for the faint
2180 of heart: it can also cause Win9x to freeze or reboot!).
2181
Raymond Hettingerf2f2a2c2002-08-19 14:25:03 +00002182- New test_pprint.py verifies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00002183 pprint.isreadable() return sensible results. Also verifies that simple
2184 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00002185
Tim Peters4324aa32001-05-28 22:30:08 +00002186C API
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002187-----
Tim Peters4324aa32001-05-28 22:30:08 +00002188
2189- Removed the unused last_is_sticky argument from the internal
2190 _PyTuple_Resize(). If this affects you, you were cheating.
Skip Montanaroe5d7f7f2002-09-20 14:16:59 +00002191
2192----
2193
2194**(For information about older versions, consult the HISTORY file.)**