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Tim Petersabf925f2001-09-28 21:53:42 +00001What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +00002Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +00003===========================
4
5Type/class unification and new-style classes
6
Guido van Rossum687ae002001-10-15 22:03:32 +00007- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +00008 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +00009 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000010 remains: the __dict__ of a new-style class is a read-only proxy; you
11 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000012 __defined__ attribute of new-style types no longer exists, for lack
13 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000014 future a __cache__ may be resurrected with a similar function, if I
15 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000016
Tim Peters1c9ca872001-10-04 06:43:12 +000017- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
18 always returned None, even when there was a class docstring).
19
20- doctest now finds and runs docstrings attached to new-style classes,
21 class methods, static methods, and properties.
22
Guido van Rossum9074ef62001-10-16 21:34:49 +000023Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +000024
Guido van Rossuma8bcf802001-10-15 15:53:58 +000025- A very subtle syntactical pitfall in list comprehensions was fixed.
26 For example: [a+b for a in 'abc', for b in 'def']. The comma in
27 this example is a mistake. Previously, this would silently let 'a'
28 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
29 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
30 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
31 Note that [a for a in <singleton>] is a convoluted way to say
32 [<singleton>] anyway, so it's not like any expressiveness is lost.
33
Guido van Rossum9074ef62001-10-16 21:34:49 +000034- getattr(obj, name, default) now only catches AttributeError, as
35 documented, rather than returning the default value for all
36 exceptions (which could mask bugs in a __getattr__ hook, for
37 example).
38
Fred Drake934d2a42001-10-18 18:18:06 +000039- Weak reference objects are now part of the core and offers a C API.
40 A bug which could allow a core dump when binary operations involved
41 proxy reference has been fixed.
42
Guido van Rossum1c486092001-10-19 02:05:35 +000043- unicode(obj) now behaves more like str(obj), accepting arbitrary
44 objects, and calling a __unicode__ method if it exists.
45 unicode(obj, encoding) and unicode(obj, encoding, errors) still
46 require an 8-bit string argument.
47
Guido van Rossum9074ef62001-10-16 21:34:49 +000048Extension modules
49
50- thread.start_new_thread() now returns the thread ID (previously None).
51
Martin v. Löwis16dc7f42001-09-30 20:32:11 +000052- binascii has now two quopri support functions, a2b_qp and b2a_qp.
53
Guido van Rossumc524d952001-10-19 01:31:59 +000054- readline now supports setting the startup_hook and the
55 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +000056
Guido van Rossumc524d952001-10-19 01:31:59 +000057- os and posix supports chroot(), setgroups() and unsetenv() where
58 available. The stat(), fstat(), statvfs() and fstatvfs() functions
59 now return "pseudo-sequences" -- the various fields can now be
60 accessed as attributes (e.g. os.stat("/").st_mtime) but for
61 backwards compatibility they also behave as a fixed-length sequence.
62 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +000063 attributes.
64
65- time: localtime(), gmtime() and strptime() now return a
66 pseudo-sequence similar to the os.stat() return value, with
67 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +000068
Guido van Rossum9074ef62001-10-16 21:34:49 +000069- Decompression objects in the zlib module now accept an optional
70 second parameter to decompress() that specifies the maximum amount
71 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +000072
Guido van Rossum9074ef62001-10-16 21:34:49 +000073Library
Guido van Rossum3c288632001-10-16 21:13:49 +000074
Tim Peters7402f792001-10-02 03:53:41 +000075- doctest now excludes functions and classes not defined by the module
76 being tested, thanks to Tim Hochberg.
77
Guido van Rossumc4b09b42001-10-04 10:19:00 +000078- profile now produces correct output in situations where an exception
79 raised in Python is cleared by C code (e.g. hasattr()). This used
80 to cause wrong output, including spurious claims of recursive
81 functions and attribution of time spent to the wrong function.
82
Tim Peters0a1fc4e2001-10-07 03:12:08 +000083 The code and documentation for the derived OldProfile and HotProfile
84 profiling classes was removed. The code hasn't worked for years (if
85 you tried to use them, they raised exceptions). OldProfile
86 intended to reproduce the behavior of the profiler Python used more
87 than 7 years ago, and isn't interesting anymore. HotProfile intended
88 to provide a faster profiler (but producing less information), and
89 that's a worthy goal we intend to meet via a different approach (but
90 without losing information).
91
Tim Peterscce092d2001-10-09 05:31:56 +000092- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +000093 a much better system-specific calibration constant. The constant can
94 now be specified in an instance constructor, or as a Profile class or
95 instance variable, instead of by editing profile.py's source code.
96 Calibration must still be done manually (see the docs for the profile
97 module).
98
99 Note that Profile.calibrate() must be overriden by subclasses.
100 Improving the accuracy required exploiting detailed knowledge of
101 profiler internals; the earlier method abstracted away the details
102 and measured a simplified model instead, but consequently computed
103 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000104
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000105- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000106 which indicates whether output is intended for the header 'Q'
107 encoding.
108
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000109- The SocketServer.ThreadingMixIn class now closes the request after
110 finish_request() returns. (Not when it errors out though.)
111
Guido van Rossumed554f62001-10-02 23:15:37 +0000112Tools/Demos
113
114- Demo/dns was removed. It no longer serves any purpose; a package
115 derived from it is now maintained by Anthony Baxter, see
116 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000117
118Build
119
120C API
121
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000122- The documentation for the tp_compare slot is updated to require that
123 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
124 not correct. This is not yet enforced but will be enforced in
125 Python 2.3; even later, we may use -2 to indicate errors and +2 for
126 "NotImplemented". Right now, -1 should be used for an error return.
127
Tim Petersd38b1c72001-09-30 05:09:37 +0000128- PyLong_AsLongLong() now accepts int (as well as long) arguments.
129 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
130 as long) arguments.
131
Guido van Rossum3c288632001-10-16 21:13:49 +0000132- PyThread_start_new_thread() now returns a long int giving the thread
133 ID, if one can be calculated; it returns -1 for error, 0 if no
134 thread ID is calculated (this is an incompatible change, but only
135 the thread module used this API). This code has only really been
136 tested on Linux and Windows; other platforms please beware (and
137 report any bugs or strange behavior).
138
Guido van Rossum1c486092001-10-19 02:05:35 +0000139- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
140 input.
141
Tim Petersabf925f2001-09-28 21:53:42 +0000142New platforms
143
144Tests
145
146Windows
147
Tim Peters04cf1d32001-10-09 22:39:40 +0000148- Installer: If you install IDLE, and don't disable file-extension
149 registration, a new "Edit with IDLE" context (right-click) menu entry
150 is created for .py and .pyw files.
151
Tim Peters1ce3cf72001-10-01 17:58:40 +0000152- The signal module now supports SIGBREAK on Windows, thanks to Steven
153 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
154 action remains to call Win32 ExitProcess(). This can be changed via
155 signal.signal(). For example:
156
157 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
158 # (SIGINT) behavior.
159 import signal
160 signal.signal(signal.SIGBREAK,
161 signal.default_int_handler)
162
163 try:
164 while 1:
165 pass
166 except KeyboardInterrupt:
167 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
168 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
169 # program without the possibility for any Python-level cleanup).
170 print "Clean exit"
171
Tim Petersabf925f2001-09-28 21:53:42 +0000172
Tim Petersb07352e2001-09-08 01:25:47 +0000173What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000174Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000175===========================
176
Guido van Rossum808eea72001-09-25 04:15:41 +0000177Type/class unification and new-style classes
178
179- pydoc and inspect are now aware of new-style classes;
180 e.g. help(list) at the interactive prompt now shows proper
181 documentation for all operations on list objects.
182
183- Applications using Jim Fulton's ExtensionClass module can now safely
184 be used with Python 2.2. In particular, Zope 2.4.1 now works with
185 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
186 examples also work again. It is hoped that Gtk and Boost also work
187 with 2.2a4 and beyond. (If you can confirm this, please write
188 webmaster@python.org; if there are still problems, please open a bug
189 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000190
Tim Peters66c1a522001-09-24 21:17:50 +0000191- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
192 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
193 in the constructed property object. fget, fset and fdel weren't
194 discoverable from Python in 2.2a3. __doc__ is new, and allows to
195 associate a docstring with a property.
196
Guido van Rossum808eea72001-09-25 04:15:41 +0000197- Comparison overloading is now more completely implemented. For
198 example, a str subclass instance can properly be compared to a str
199 instance, and it can properly overload comparison. Ditto for most
200 other built-in object types.
201
202- The repr() of new-style classes has changed; instead of <type
203 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
204 *except* for built-in types, which are still rendered as <type
205 'Foo'> (to avoid upsetting existing code that might parse or
206 otherwise rely on repr() of certain type objects).
207
208- The repr() of new-style objects is now always <Foo object at XXX>;
209 previously, it was sometimes <Foo instance at XXX>.
210
211- For new-style classes, what was previously called __getattr__ is now
212 called __getattribute__. This method, if defined, is called for
213 *every* attribute access. A new __getattr__ hook mor similar to the
214 one in classic classes is defined which is called only if regular
215 attribute access raises AttributeError; to catch *all* attribute
216 access, you can use __getattribute__ (for new-style classes). If
217 both are defined, __getattribute__ is called first, and if it raises
218 AttributeError, __getattr__ is called.
219
220- The __class__ attribute of new-style objects can be assigned to.
221 The new class must have the same C-level object layout as the old
222 class.
223
224- The builtin file type can be subclassed now. In the usual pattern,
225 "file" is the name of the builtin type, and file() is a new builtin
226 constructor, with the same signature as the builtin open() function.
227 file() is now the preferred way to open a file.
228
229- Previously, __new__ would only see sequential arguments passed to
230 the type in a constructor call; __init__ would see both sequential
231 and keyword arguments. This made no sense whatsoever any more, so
232 now both __new__ and __init__ see all arguments.
233
234- Previously, hash() applied to an instance of a subclass of str or
235 unicode always returned 0. This has been repaired.
236
237- Previously, an operation on an instance of a subclass of an
238 immutable type (int, long, float, complex, tuple, str, unicode),
239 where the subtype didn't override the operation (and so the
240 operation was handled by the builtin type), could return that
241 instance instead a value of the base type. For example, if s was of
242 a str sublass type, s[:] returned s as-is. Now it returns a str
243 with the same value as s.
244
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000245- Provisional support for pickling new-style objects has been added.
246
Guido van Rossum808eea72001-09-25 04:15:41 +0000247Core
248
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000249- file.writelines() now accepts any iterable object producing strings.
250
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000251- PyUnicode_FromEncodedObject() now works very much like
252 PyObject_Str(obj) in that it tries to use __str__/tp_str
253 on the object if the object is not a string or buffer. This
254 makes unicode() behave like str() when applied to non-string/buffer
255 objects.
256
Martin v. Löwis2777c022001-09-19 13:47:32 +0000257- PyFile_WriteObject now passes Unicode object to the file's write
258 method. As a result, all file-like object which may be the target
259 of a print statement must support Unicode objects, i.e. they must
260 at least convert them into ASCII strings.
261
Guido van Rossum624c8af2001-09-18 15:21:04 +0000262- Thread scheduling on Solaris should be improved; it is no longer
263 necessary to insert a small sleep at the start of a thread in order
264 to let other runnable threads be scheduled.
265
Tim Petersb07352e2001-09-08 01:25:47 +0000266Library
267
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000268- StringIO.StringIO instances and cStringIO.StringIO instances support
269 read character buffer compatible objects for their .write() methods.
270 These objects are converted to strings and then handled as such
271 by the instances.
272
Barry Warsaw2f600732001-09-24 04:28:10 +0000273- The "email" package has been added. This is basically a port of the
274 mimelib package <http://sf.net/projects/mimelib> with API changes
275 and some implementations updated to use iterators and generators.
276
Tim Peters8a9c2842001-09-22 21:30:22 +0000277- difflib.ndiff() and difflib.Differ.compare() are generators now. This
278 restores the ability of Tools/scripts/ndiff.py to start producing output
279 before the entire comparison is complete.
280
Barry Warsaw58b072d2001-09-22 04:44:21 +0000281- StringIO.StringIO instances and cStringIO.StringIO instances support
282 iteration just like file objects (i.e. their .readline() method is
283 called for each iteration until it returns an empty string).
284
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000285- The codecs module has grown four new helper APIs to access
286 builtin codecs: getencoder(), getdecoder(), getreader(),
287 getwriter().
288
Guido van Rossum624c8af2001-09-18 15:21:04 +0000289- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
290 simplifies writing XML RPC servers.
291
Barry Warsaw647d5e82001-09-28 17:01:02 +0000292- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000293 after interpretation of symbolic links. On non-Unix systems, this
294 is an alias for os.path.abspath().
295
Tim Peters16a77ad2001-09-08 04:00:12 +0000296- operator.indexOf() (PySequence_Index() in the C API) now works with any
297 iterable object.
298
Guido van Rossum624c8af2001-09-18 15:21:04 +0000299- smtplib now supports various authentication and security features of
300 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000301
Guido van Rossum624c8af2001-09-18 15:21:04 +0000302- hmac: a new module implementing keyed hashing for message
303 authentication.
304
305- mimetypes now recognizes more extensions and file types. At the
306 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000307
Guido van Rossum624c8af2001-09-18 15:21:04 +0000308- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000309 Python 2.2 bytecode generation. It has also been promoted from a
310 Tool to a standard library package. (Tools/compiler still exists as
311 a sample driver.)
312
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000313Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000314
Tim Petersb07352e2001-09-08 01:25:47 +0000315Build
316
Guido van Rossum624c8af2001-09-18 15:21:04 +0000317- Large file support (LFS) is now automatic when the platform supports
318 it; no more manual configuration tweaks are needed. On Linux, at
319 least, it's possible to have a system whose C library supports large
320 files but whose kernel doesn't; in this case, large file support is
321 still enabled but doesn't do you any good unless you upgrade your
322 kernel or share your Python executable with another system whose
323 kernel has large file support.
324
325- The configure script now supplies plausible defaults in a
326 cross-compilation environment. This doesn't mean that the supplied
327 values are always correct, or that cross-compilation now works
328 flawlessly -- but it's a first step (and it shuts up most of
329 autoconf's warnings about AC_TRY_RUN).
330
331- The Unix build is now a bit less chatty, courtesy of the parser
332 generator. The build is completely silent (except for errors) when
333 using "make -s", thanks to a -q option to setup.py.
334
Tim Petersb07352e2001-09-08 01:25:47 +0000335C API
336
Guido van Rossum624c8af2001-09-18 15:21:04 +0000337- The "structmember" API now supports some new flag bits to deny read
338 and/or write access to attributes in restricted execution mode.
339
Tim Petersb07352e2001-09-08 01:25:47 +0000340New platforms
341
Guido van Rossum624c8af2001-09-18 15:21:04 +0000342- Compaq's iPAQ handheld, running the "familiar" Linux distribution
343 (http://familiar.handhelds.org).
344
Tim Petersb07352e2001-09-08 01:25:47 +0000345Tests
346
Tim Peters8a9c2842001-09-22 21:30:22 +0000347- The "classic" standard tests, which work by comparing stdout to
348 an expected-output file under Lib/test/output/, no longer stop at
349 the first mismatch. Instead the test is run to completion, and a
350 variant of ndiff-style comparison is used to report all differences.
351 This is much easier to understand than the previous style of reporting.
352
353- The unittest-based standard tests now use regrtest's test_main()
354 convention, instead of running as a side-effect of merely being
355 imported. This allows these tests to be run in more natural and
356 flexible ways as unittests, outside the regrtest framework.
357
358- regrtest.py is much better integrated with unittest and doctest now,
359 especially in regard to reporting errors.
360
Tim Petersb07352e2001-09-08 01:25:47 +0000361Windows
362
Guido van Rossum624c8af2001-09-18 15:21:04 +0000363- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000364 that support it (NTFS under Windows 2000). See "What's New in
365 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000366
Tim Petersb07352e2001-09-08 01:25:47 +0000367
Tim Petersedc99312001-08-22 21:36:50 +0000368What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000369Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000370===========================
371
372Core
373
Tim Peters9fffa3e2001-09-04 05:14:19 +0000374- Conversion of long to float now raises OverflowError if the long is too
375 big to represent as a C double.
376
Tim Peters32f453e2001-09-03 08:35:41 +0000377- The 3-argument builtin pow() no longer allows a third non-None argument
378 if either of the first two arguments is a float, or if both are of
379 integer types and the second argument is negative (in which latter case
380 the arguments are converted to float, so this is really the same
381 restriction).
382
Tim Peters5d2b77c2001-09-03 05:47:38 +0000383- The builtin dir() now returns more information, and sometimes much
384 more, generally naming all attributes of an object, and all attributes
385 reachable from the object via its class, and from its class's base
386 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
387 an empty list. In 2.2a3,
388
389 >>> dir([])
390 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
391 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
392 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
393 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
394 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
395 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
396 'reverse', 'sort']
397
398 dir(module) continues to return only the module's attributes, though.
399
Tim Petersbdee63f2001-09-02 03:40:59 +0000400- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000401 than raising OverflowError. This is a partial implementation of PEP
402 237. You can use -Wdefault::OverflowWarning to enable a warning for
403 this situation, and -Werror::OverflowWarning to revert to the old
404 OverflowError exception.
405
Guido van Rossum61c345f2001-09-04 03:26:15 +0000406- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000407 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000408 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
409 -Qold, meaning the / operator has its classic meaning and no
410 warnings are issued. Using -Qwarn issues a run-time warning about
411 all uses of classic division for int and long arguments; -Qwarnall
412 also warns about classic division for float and complex arguments
413 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
414 new division by default, but only in the __main__ module. You can
415 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
416 __main__ module new division, and warns about classic division
417 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000418
Tim Petersbdee63f2001-09-02 03:40:59 +0000419- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000420 long, float, str, unicode, and tuple. (The types complex, list and
421 dictionary can also be subclassed; this was introduced earlier.)
422 Note that restrictions apply when subclassing immutable built-in
423 types: you can only affect the value of the instance by overloading
424 __new__. You can add mutable attributes, and the subclass instances
425 will have a __dict__ attribute, but you cannot change the "value"
426 (as implemented by the base class) of an immutable subclass instance
427 once it is created.
428
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000429- The dictionary constructor now takes an optional argument, a
430 mapping-like object, and initializes the dictionary from its
431 (key, value) pairs.
432
Tim Petersbdee63f2001-09-02 03:40:59 +0000433- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000434 "cooperative super calls" in a multiple inheritance setting. For an
435 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
436
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000437- A new built-in type, property, has been added. This enables the
438 creation of "properties". These are attributes implemented by
439 getter and setter functions (or only one of these for read-only or
440 write-only attributes), without the need to override __getattr__.
441 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000442
Tim Petersbdee63f2001-09-02 03:40:59 +0000443- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000444 liberalized, to allow leading zeroes. Examples of literals now
445 legal that were SyntaxErrors before:
446
447 00.0 0e3 0100j 07.5 00000000000000000008.
448
Tim Petersbdee63f2001-09-02 03:40:59 +0000449- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000450 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
451
Tim Petersedc99312001-08-22 21:36:50 +0000452Library
453
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000454- telnetlib includes symbolic names for the options, and support for
455 setting an option negotiation callback.
456
Tim Petersa40c7932001-09-05 22:36:56 +0000457- The new C standard no longer requires that math libraries set errno to
458 ERANGE on overflow. For platform libraries that exploit this new
459 freedom, Python's overflow-checking was wholly broken. A new overflow-
460 checking scheme attempts to repair that, but may not be reliable on all
461 platforms (C doesn't seem to provide anything both useful and portable
462 in this area anymore).
463
Martin v. Löwis44f86962001-09-05 13:44:54 +0000464- Asynchronous timeout actions are available through the new class
465 threading.Timer.
466
Tim Peters78526162001-09-05 00:53:45 +0000467- math.log and math.log10 now return sensible results for even huge
468 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
469
Tim Petersbdee63f2001-09-02 03:40:59 +0000470- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000471 currently held. See the docs for the imp module.
472
Tim Petersbdee63f2001-09-02 03:40:59 +0000473- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000474 dumps containing ints written on platforms where Python ints are 8 bytes.
475 When read on a box where Python ints are 4 bytes, such values are
476 converted to Python longs.
477
Tim Petersbdee63f2001-09-02 03:40:59 +0000478- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000479 code objects is no longer allowed. This plugs a security hole.
480
Steve Purcell6091cd62001-09-06 16:05:17 +0000481- unittest.TestResult instances no longer store references to tracebacks
482 generated by test failures. This prevents unexpected dangling references
483 to objects that should be garbage collected between tests.
484
Tim Petersedc99312001-08-22 21:36:50 +0000485Tools
486
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000487- Tools/scripts/fixdiv.py has been added which can be used to fix
488 division operators as per PEP 238.
489
Tim Petersedc99312001-08-22 21:36:50 +0000490Build
491
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000492- If you are an adventurous person using Mac OS X you may want to look at
493 Mac/OSX. There is a Makefile there that will build Python as a real Mac
494 application, which can be used for experimenting with Carbon or Cocoa.
495 Discussion of this on pythonmac-sig, please.
496
Tim Peters7eea37e2001-09-04 22:08:56 +0000497C API
498
499- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000500
Tim Peters9fffa3e2001-09-04 05:14:19 +0000501- Note that PyLong_AsDouble can fail! This has always been true, but no
502 callers checked for it. It's more likely to fail now, because overflow
503 errors are properly detected now. The proper way to check:
504
505 double x = PyLong_AsDouble(some_long_object);
506 if (x == -1.0 && PyErr_Occurred()) {
507 /* The conversion failed. */
508 }
509
Tim Petersbdee63f2001-09-02 03:40:59 +0000510- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000511 compile but will not participate in GC. To upgrade an extension
512 module:
513
514 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000515
Neil Schemenauer4042c692001-08-30 15:38:01 +0000516 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
517 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000518
Neil Schemenauer4042c692001-08-30 15:38:01 +0000519 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
520 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000521
Neil Schemenauer4042c692001-08-30 15:38:01 +0000522 - remove PyGC_HEAD_SIZE from object size calculations
523
524 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
525
Tim Petersbdee63f2001-09-02 03:40:59 +0000526- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000527 These can be used safely to construct string objects from a
528 sprintf-style format string (similar to the format string supported
529 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000530
Tim Petersedc99312001-08-22 21:36:50 +0000531New platforms
532
Tim Petersb7da0902001-09-02 23:01:43 +0000533- Stephen Hansen contributed patches sufficient to get a clean compile
534 under Borland C (Windows), but he reports problems running it and ran
535 out of time to complete the port. Volunteers? Expect a MemoryError
536 when importing the types module; this is probably shallow, and
537 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000538
Tim Petersedc99312001-08-22 21:36:50 +0000539Tests
540
541Windows
542
Tim Peters6e13a562001-09-06 00:32:15 +0000543- Large file support is now enabled on Win32 platforms as well as on
544 Win64. This means that, for example, you can use f.tell() and f.seek()
545 to manipulate files larger than 2 gigabytes (provided you have enough
546 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000547 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
548 filesize limit, and large file support makes no difference there.
549 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
550 NTFS has no practical limit on file size, and files of any size can be
551 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000552
Tim Petersbdee63f2001-09-02 03:40:59 +0000553- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000554 points to command.com (patch from Brian Quinlan).
555
Tim Petersedc99312001-08-22 21:36:50 +0000556
Tim Peters20f51a72001-07-21 02:31:40 +0000557What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000558Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000559===========================
560
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000561Build
562
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000563- Tim Peters developed a brand new Windows installer using Wise 8.1,
564 generously donated to us by Wise Solutions.
565
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000566- configure supports a new option --enable-unicode, with the values
567 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
568 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000569
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000570- A new configure option --enable-framework builds a Mac OS X framework,
571 which "make frameworkinstall" will install. This provides a starting
572 point for more mac-like functionality, join pythonmac-sig@python.org
573 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000574
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000575- The NeXT platform is no longer supported.
576
577- The `new' module is now statically linked.
578
Tim Peters0afb6092001-08-15 06:06:44 +0000579Tools
580
581- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000582 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000583 the module docstring for details.
584
Tim Peters20f51a72001-07-21 02:31:40 +0000585Tests
586
Tim Peters5e824c32001-08-12 22:25:01 +0000587- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000588 platforms, allowing to give clearer test result output. regrtest
589 also has optional --use/-u switch to run normally disabled tests
590 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000591
Tim Peters20f51a72001-07-21 02:31:40 +0000592- Several new tests in the standard test suite, with special thanks to
593 Nick Mathewson.
594
595Core
596
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000597- The floor division operator // has been added as outlined in PEP
598 238. The / operator still provides classic division (and will until
599 Python 3.0) unless "from __future__ import division" is included, in
600 which case the / operator will provide true division. The operator
601 module provides truediv() and floordiv() functions. Augmented
602 assignment variants are included, as are the equivalent overloadable
603 methods and C API methods. See the PEP for a full discussion:
604 <http://python.sf.net/peps/pep-0238.html>
605
Tim Peters6cd6a822001-08-17 22:11:27 +0000606- Future statements are now effective in simulated interactive shells
607 (like IDLE). This should "just work" by magic, but read Michael
608 Hudson's "Future statements in simulated shells" PEP 264 for full
609 details: <http://python.sf.net/peps/pep-0264.html>.
610
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000611- The type/class unification (PEP 252-253) was integrated into the
612 trunk and is not so tentative any more (the exact specification of
613 some features is still tentative). A lot of work has done on fixing
614 bugs and adding robustness and features (performance still has to
615 come a long way).
616
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000617- Warnings about a mismatch in the Python API during extension import
618 now use the Python warning framework (which makes it possible to
619 write filters for these warnings).
620
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000621- A function's __dict__ (aka func_dict) will now always be a
622 dictionary. It used to be possible to delete it or set it to None,
623 but now both actions raise TypeErrors. It is still legal to set it
624 to a dictionary object. Getting func.__dict__ before any attributes
625 have been assigned now returns an empty dictionary instead of None.
626
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000627- A new command line option, -E, was added which disables the use of
628 all environment variables, or at least those that are specifically
629 significant to Python. Usually those have a name starting with
630 "PYTHON". This was used to fix a problem where the tests fail if
631 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
632 older distribution.
633
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000634Library
635
Tim Peters5e824c32001-08-12 22:25:01 +0000636- New class Differ and new functions ndiff() and restore() in difflib.py.
637 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000638 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000639
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000640- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
641 value using the minimal quoting required for the value; more
642 reliable than using xml.sax.saxutils.escape() for attribute values.
643
644- Readline completion support for cmd.Cmd was added.
645
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000646- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
647
648- Added function threading.BoundedSemaphore()
649
650- Added Ka-Ping Yee's cgitb.py module.
651
652- The `new' module now exposes the CO_xxx flags.
653
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000654New platforms
655
656C API
657
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000658- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
659 which provide a cross-platform implementations for the
660 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
661 the standard sprintf() and vsprintf() C lib APIs, these versions
662 apply bounds checking on the used buffer which enhances protection
663 against buffer overruns.
664
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000665- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000666 and extensions using different Unicode widths is rendered next to
667 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000668 will result in an ImportError. Unicode extensions writers must make
669 sure to check the Unicode width compatibility in their extensions by
670 using at least one of the mangled Unicode APIs in the extension.
671
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000672- Two new flags METH_NOARGS and METH_O are available in method definition
673 tables to simplify implementation of methods with no arguments and a
674 single untyped argument. Calling such methods is more efficient than
675 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
676 deprecated.
677
Tim Petersc1731372001-08-04 08:12:36 +0000678Windows
679
680- "import module" now compiles module.pyw if it exists and nothing else
681 relevant is found.
682
Tim Peters20f51a72001-07-21 02:31:40 +0000683
Guido van Rossum55a78992001-07-17 17:22:32 +0000684What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000685===========================
686
687Core
Tim Petersa814db52001-05-14 07:05:58 +0000688
Tim Peters6d6c1a32001-08-02 04:15:00 +0000689- TENTATIVELY, a large amount of code implementing much of what's
690 described in PEP 252 (Making Types Look More Like Classes) and PEP
691 253 (Subtyping Built-in Types) was added. This will be released
692 with Python 2.2a1. Documentation will be provided separately
693 through http://www.python.org/2.2/. The purpose of releasing this
694 with Python 2.2a1 is to test backwards compatibility. It is
695 possible, though not likely, that a decision is made not to release
696 this code as part of 2.2 final, if any serious backwards
697 incompapatibilities are found during alpha testing that cannot be
698 repaired.
699
Guido van Rossum55a78992001-07-17 17:22:32 +0000700- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000701 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000702 more 'yield' statements. See PEP 255. Since this adds a new
703 keyword to the language, this feature must be enabled by including a
704 future statement: "from __future__ import generators" (see PEP 236).
705 Generators will become a standard feature in a future release
706 (probably 2.3). Without this future statement, 'yield' remains an
707 ordinary identifier, but a warning is issued each time it is used.
708 (These warnings currently don't conform to the warnings framework of
709 PEP 230; we intend to fix this in 2.2a2.)
710
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000711- The UTF-16 codec was modified to be more RFC compliant. It will now
712 only remove BOM characters at the start of the string and then
713 only if running in native mode (UTF-16-LE and -BE won't remove a
714 leading BMO character).
715
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000716- Strings now have a new method .decode() to complement the already
717 existing .encode() method. These two methods provide direct access
718 to the corresponding decoders and encoders of the registered codecs.
719
720 To enhance the usability of the .encode() method, the special
721 casing of Unicode object return values was dropped (Unicode objects
722 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000723
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000724 Both methods will now return whatever the codec in charge of the
725 requested encoding returns as object, e.g. Unicode codecs will
726 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
727 will return u"äöü"). This enables codec writer to create codecs
728 for various simple to use conversions.
729
730 New codecs were added to demonstrate these new features (the .encode()
731 and .decode() columns indicate the type of the returned objects):
732
733 Name | .encode() | .decode() | Description
734 ----------------------------------------------------------------------
735 uu | string | string | UU codec (e.g. for email)
736 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000737 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000738 zlib | string | string | zlib compression
739 hex | string | string | 2-byte hex codec
740 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
741
Mark Hammond2a0af792001-05-14 03:09:36 +0000742- Some operating systems now support the concept of a default Unicode
743 encoding for file system operations. Notably, Windows supports 'mbcs'
744 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000745 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000746 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000747
748 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000749 functions that return filenames (such as os.listdir()) to return Python
750 string objects pre-encoded using the default file system encoding for
751 the platform. As this encoding is likely to be different from Python's
752 default encoding, converting this name to a Unicode object before passing
753 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000754 would attempt to use its default encoding (generally ASCII) rather than
755 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000756
Tim Petersa814db52001-05-14 07:05:58 +0000757 In general, this change simply removes surprises when working with
758 Unicode and the file system, making these operations work as you expect,
759 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000760 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000761
Tim Peters61dff2b2001-05-08 15:43:37 +0000762- Float (and complex) literals in source code were evaluated to full
763 precision only when running from a .py file; the same code loaded from a
764 .pyc (or .pyo) file could suffer numeric differences starting at about the
765 12th significant decimal digit. For example, on a machine with IEEE-754
766 floating arithmetic,
767
768 x = 9007199254740992.0
769 print long(x)
770
771 printed 9007199254740992 if run directly from .py, but 9007199254740000
772 if from a compiled (.pyc or .pyo) file. This was due to marshal using
773 str(float) instead of repr(float) when building code objects. marshal
774 now uses repr(float) instead, which should reproduce floats to full
775 machine precision (assuming the platform C float<->string I/O conversion
776 functions are of good quality).
777
778 This may cause floating-point results to change in some cases, and
779 usually for the better, but may also cause numerically unstable
780 algorithms to break.
781
Tim Peters2f228e72001-05-13 00:19:31 +0000782- The implementation of dicts suffers fewer collisions, which has speed
783 benefits. However, the order in which dict entries appear in dict.keys(),
784 dict.values() and dict.items() may differ from previous releases for a
785 given dict. Nothing is defined about this order, so no program should
786 rely on it. Nevertheless, it's easy to write test cases that rely on the
787 order by accident, typically because of printing the str() or repr() of a
788 dict to an "expected results" file. See Lib/test/test_support.py's new
789 sortdict(dict) function for a simple way to display a dict in sorted
790 order.
791
Tim Peters7a3bfc32001-06-12 01:22:22 +0000792- Many other small changes to dicts were made, resulting in faster
793 operation along the most common code paths.
794
Guido van Rossum10315822001-05-01 20:54:30 +0000795- Dictionary objects now support the "in" operator: "x in dict" means
796 the same as dict.has_key(x).
797
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000798- The update() method of dictionaries now accepts generic mapping
799 objects. Specifically the argument object must support the .keys()
800 and __getitem__() methods. This allows you to say, for example,
801 {}.update(UserDict())
802
Guido van Rossum10315822001-05-01 20:54:30 +0000803- Iterators were added; this is a generalized way of providing values
804 to a for loop. See PEP 234. There's a new built-in function iter()
805 to return an iterator. There's a new protocol to get the next value
806 from an iterator using the next() method (in Python) or the
807 tp_iternext slot (in C). There's a new protocol to get iterators
808 using the __iter__() method (in Python) or the tp_iter slot (in C).
809 Iterating (i.e. a for loop) over a dictionary generates its keys.
810 Iterating over a file generates its lines.
811
Tim Petersf553f892001-05-01 20:45:31 +0000812- The following functions were generalized to work nicely with iterator
813 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000814 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000815 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
816 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000817 join() method of strings
818 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000819 'x in y' and 'x not in y' (PySequence_Contains() in C API)
820 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000821 right-hand side of assignment statements with multiple targets, such as
822 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000823
Tim Petersd85e1022001-05-11 21:51:48 +0000824- Accessing module attributes is significantly faster (for example,
825 random.random or os.path or yourPythonModule.yourAttribute).
826
Tim Peterse63415e2001-05-08 04:38:29 +0000827- Comparing dictionary objects via == and != is faster, and now works even
828 if the keys and values don't support comparisons other than ==.
829
Tim Peters95bf9392001-05-10 08:32:44 +0000830- Comparing dictionaries in ways other than == and != is slower: there were
831 insecurities in the dict comparison implementation that could cause Python
832 to crash if the element comparison routines for the dict keys and/or
833 values mutated the dicts. Making the code bulletproof slowed it down.
834
Tim Peterseb28ef22001-06-02 05:27:19 +0000835- Collisions in dicts are resolved via a new approach, which can help
836 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000837 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000838 faster now. Thanks to Christian Tismer for pointing out the cause and
839 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000840
Tim Peters52e155e2001-06-16 05:42:57 +0000841- repr() is much faster for large containers (dict, list, tuple).
842
843
Tim Petersa814db52001-05-14 07:05:58 +0000844Library
845
Fred Drake960fdf92001-07-20 18:38:26 +0000846- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
847 were added to the string module. These a locale-indenpendent
848 constants, unlike letters, lowercase, and uppercase. These are now
849 use in appropriate locations in the standard library.
850
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000851- The flags used in dlopen calls can now be configured using
852 sys.setdlopenflags and queried using sys.getdlopenflags.
853
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000854- Fredrik Lundh's xmlrpclib is now a standard library module. This
855 provides full client-side XML-RPC support. In addition,
856 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
857 one asyncore-based). Thanks to Eric Raymond for the documentation.
858
Guido van Rossum643d3912001-07-05 14:46:25 +0000859- The xrange() object is simplified: it no longer supports slicing,
860 repetition, comparisons, efficient 'in' checking, the tolist()
861 method, or the start, stop and step attributes. See PEP 260.
862
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000863- A new function fnmatch.filter to filter lists of file names was added.
864
Barry Warsawffd674d2001-05-22 16:00:10 +0000865- calendar.py uses month and day names based on the current locale.
866
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000867- strop is now *really* obsolete (this was announced before with 1.6),
868 and issues DeprecationWarning when used (except for the four items
869 that are still imported into string.py).
870
Tim Petersa814db52001-05-14 07:05:58 +0000871- Cookie.py now sorts key+value pairs by key in output strings.
872
873- pprint.isrecursive(object) didn't correctly identify recursive objects.
874 Now it does.
875
Tim Peters95b3f782001-05-14 18:39:41 +0000876- pprint functions now much faster for large containers (tuple, list, dict).
877
Tim Peters7b9542a2001-06-10 23:40:19 +0000878- New 'q' and 'Q' format codes in the struct module, corresponding to C
879 types "long long" and "unsigned long long" (on Windows, __int64). In
880 native mode, these can be used only when the platform C compiler supports
881 these types (when HAVE_LONG_LONG is #define'd by the Python config
882 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000883 In standard mode, 'q' and 'Q' are supported on all platforms, and are
884 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000885
Guido van Rossum83213cc2001-06-12 16:48:52 +0000886- The site module installs a new built-in function 'help' that invokes
887 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
888 it displays a message reminding the user to use 'help()' or
889 'help(object)'.
890
Tim Petersa814db52001-05-14 07:05:58 +0000891Tests
892
893- New test_mutants.py runs dict comparisons where the key and value
894 comparison operators mutute the dicts randomly during comparison. This
895 rapidly causes Python to crash under earlier releases (not for the faint
896 of heart: it can also cause Win9x to freeze or reboot!).
897
898- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000899 pprint.isreadable() return sensible results. Also verifies that simple
900 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000901
Tim Peters4324aa32001-05-28 22:30:08 +0000902C API
903
904- Removed the unused last_is_sticky argument from the internal
905 _PyTuple_Resize(). If this affects you, you were cheating.
906
907
Guido van Rossum55a78992001-07-17 17:22:32 +0000908======================================================================
909
910
Guido van Rossumffe13be2001-04-16 18:46:45 +0000911What's New in Python 2.1 (final)?
912=================================
913
914We only changed a few things since the last release candidate, all in
915Python library code:
916
917- A bug in the locale module was fixed that affected locales which
918 define no grouping for numeric formatting.
919
920- A few bugs in the weakref module's implementations of weak
921 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
922 and the test suite was updated to check for these bugs.
923
924- An old bug in the os.path.walk() function (introduced in Python
925 2.0!) was fixed: a non-existent file would cause an exception
926 instead of being ignored.
927
928- Fixed a few bugs in the new symtable module found by Neil Norwitz's
929 PyChecker.
930
931
Guido van Rossum5b08f132001-04-16 02:05:23 +0000932What's New in Python 2.1c2?
933===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000934
Guido van Rossum5b08f132001-04-16 02:05:23 +0000935A flurry of small changes, and one showstopper fixed in the nick of
936time made it necessary to release another release candidate. The list
937here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000938
Guido van Rossum5b08f132001-04-16 02:05:23 +0000939Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000940
Guido van Rossum5b08f132001-04-16 02:05:23 +0000941- Tim discovered a nasty bug in the dictionary code, caused by
942 PyDict_Next() calling dict_resize(), and the GC code's use of
943 PyDict_Next() violating an assumption in dict_items(). This was
944 fixed with considerable amounts of band-aid, but the net effect is a
945 saner and more robust implementation.
946
947- Made a bunch of symbols static that were accidentally global.
948
949Build and Ports
950
951- The setup.py script didn't check for a new enough version of zlib
952 (1.1.3 is needed). Now it does.
953
954- Changed "make clean" target to also remove shared libraries.
955
956- Added a more general warning about the SGI Irix optimizer to README.
957
958Library
959
960- Fix a bug in urllib.basejoin("http://host", "../file.html") which
961 omitted the slash between host and file.html.
962
963- The mailbox module's _Mailbox class contained a completely broken
964 and undocumented seek() method. Ripped it out.
965
966- Fixed a bunch of typos in various library modules (urllib2, smtpd,
967 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
968
969- Fixed a few last-minute bugs in unittest.
970
971Extensions
972
973- Reverted the patch to the OpenSSL code in socketmodule.c to support
974 RAND_status() and the EGD, and the subsequent patch that tried to
975 fix it for pre-0.9.5 versions; the problem with the patch is that on
976 some systems it issues a warning whenever socket is imported, and
977 that's unacceptable.
978
979Tests
980
981- Fixed the pickle tests to work with "import test.test_pickle".
982
983- Tweaked test_locale.py to actually run the test Windows.
984
985- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
986 not "wb" (which is not a valid mode at all).
987
988- Fix pstats browser crashes. Import readline if it exists to make
989 the user interface nicer.
990
991- Add "import thread" to the top of test modules that import the
992 threading module (test_asynchat and test_threadedtempfile). This
993 prevents test failures caused by a broken threading module resulting
994 from a previously caught failed import.
995
996- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
997 needed on some platforms (e.g. Solaris 8) when the tests are run
998 twice in succession.
999
1000- Skip rather than fail test_sunaudiodev if no audio device is found.
1001
1002
1003What's New in Python 2.1c1?
1004===========================
1005
1006This list was significantly updated when 2.1c2 was released; the 2.1c1
1007release didn't mention most changes that were actually part of 2.1c1:
1008
1009Legal
1010
1011- Copyright was assigned to the Python Software Foundation (PSF) and a
1012 PSF license (very similar to the CNRI license) was added.
1013
1014- The CNRI copyright notice was updated to include 2001.
1015
1016Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001017
Guido van Rossumc9932722001-04-12 02:31:27 +00001018- After a public outcry, assignment to __debug__ is no longer illegal;
1019 instead, a warning is issued. It will become illegal in 2.2.
1020
Guido van Rossum5b08f132001-04-16 02:05:23 +00001021- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1022 "%#x" now always prepends "0x", even if the value is zero.
1023
1024- Fixed some nits in the bytecode compiler.
1025
1026- Fixed core dumps when calling certain kinds of non-functions.
1027
1028- Fixed various core dumps caused by reference count bugs.
1029
1030Build and Ports
1031
1032- Use INSTALL_SCRIPT to install script files.
1033
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001034- New port: SCO Unixware 7, by Billy G. Allie.
1035
Guido van Rossum5b08f132001-04-16 02:05:23 +00001036- Updated RISCOS port.
1037
1038- Updated BeOS port and notes.
1039
1040- Various other porting problems resolved.
1041
1042Library
1043
1044- The TERMIOS and SOCKET modules are now truly obsolete and
1045 unnecessary. Their symbols are incorporated in the termios and
1046 socket modules.
1047
1048- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1049 better tests for pickling.
1050
1051- threading: make Condition.wait() robust against KeyboardInterrupt.
1052
1053- zipfile: add support to zipfile to support opening an archive
1054 represented by an open file rather than a file name. Fix bug where
1055 the archive was not properly closed. Fixed a bug in this bugfix
1056 where flush() was called for a read-only file.
1057
1058- imputil: added an uninstall() method to the ImportManager.
1059
1060- Canvas: fixed bugs in lower() and tkraise() methods.
1061
1062- SocketServer: API change (added overridable close_request() method)
1063 so that the TCP server can explicitly close the request.
1064
1065- pstats: Eric Raymond added a simple interactive statistics browser,
1066 invoked when the module is run as a script.
1067
1068- locale: fixed a problem in format().
1069
1070- webbrowser: made it work when the BROWSER environment variable has a
1071 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1072 KDE 2. Fixed some other nits.
1073
1074- unittest: changes to allow using a different exception than
1075 AssertionError, and added a few more function aliases. Some other
1076 small changes.
1077
1078- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1079
1080- asynchat: fixed a critical bug in asynchat that slipped through the
1081 2.1b2 release. Fixed another rare bug.
1082
1083- Fix some unqualified except: clauses (always a bad code example).
1084
1085XML
1086
1087- pyexpat: new API get_version_string().
1088
1089- Fixed some minidom bugs.
1090
1091Extensions
1092
1093- Fixed a core dump in _weakref. Removed the weakref.mapping()
1094 function (it adds nothing to the API).
1095
1096- Rationalized the use of header files in the readline module, to make
1097 it compile (albeit with some warnings) with the very recent readline
1098 4.2, without breaking for earlier versions.
1099
1100- Hopefully fixed a buffering problem in linuxaudiodev.
1101
1102- Attempted a fix to make the OpenSSL support in the socket module
1103 work again with pre-0.9.5 versions of OpenSSL.
1104
1105Tests
1106
1107- Added a test case for asynchat and asyncore.
1108
1109- Removed coupling between tests where one test failing could break
1110 another.
1111
1112Tools
1113
1114- Ping added an interactive help browser to pydoc, fixed some nits
1115 in the rest of the pydoc code, and added some features to his
1116 inspect module.
1117
1118- An updated python-mode.el version 4.1 which integrates Ken
1119 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1120 much nicer in XEmacs and Emacs. When stepping through your program
1121 with pdb, in either the shell window or the *Python* window, the
1122 source file and line will be tracked by an arrow. Very cool!
1123
1124- IDLE: syntax warnings in interactive mode are changed into errors.
1125
1126- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001127 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001128
1129- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001130
Barry Warsaw11e89c72001-04-11 20:37:57 +00001131
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001132What's New in Python 2.1 beta 2?
1133================================
1134
Guido van Rossum053ae352001-03-22 14:17:21 +00001135(Unlisted are many fixed bugs, more documentation, etc.)
1136
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001137Core language, builtins, and interpreter
1138
Guido van Rossum053ae352001-03-22 14:17:21 +00001139- The nested scopes work (enabled by "from __future__ import
1140 nested_scopes") is completed; in particular, the future now extends
1141 into code executed through exec, eval() and execfile(), and into the
1142 interactive interpreter.
1143
1144- When calling a base class method (e.g. BaseClass.__init__(self)),
1145 this is now allowed even if self is not strictly spoken a class
1146 instance (e.g. when using metaclasses or the Don Beaudry hook).
1147
1148- Slice objects are now comparable but not hashable; this prevents
1149 dict[:] from being accepted but meaningless.
1150
1151- Complex division is now calculated using less braindead algorithms.
1152 This doesn't change semantics except it's more likely to give useful
1153 results in extreme cases. Complex repr() now uses full precision
1154 like float repr().
1155
1156- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1157
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001158- It is illegal to assign to the name __debug__, which is set when the
1159 interpreter starts. It is effectively a compile-time constant.
1160
1161- A warning will be issued if a global statement for a variable
1162 follows a use or assignment of that variable.
1163
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001164Standard library
1165
Guido van Rossum053ae352001-03-22 14:17:21 +00001166- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1167 inspired by JUnit), is now part of the standard library. You now
1168 have a choice of two testing frameworks: unittest requires you to
1169 write testcases as separate code, doctest gathers them from
1170 docstrings. Both approaches have their advantages and
1171 disadvantages.
1172
1173- A new module Tix was added, which wraps the Tix extension library
1174 for Tk. With that module, it is not necessary to statically link
1175 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1176 require" command. See Demo/tix/.
1177
1178- tzparse.py is now obsolete.
1179
1180- In gzip.py, the seek() and tell() methods are removed -- they were
1181 non-functional anyway, and it's better if callers can test for their
1182 existence with hasattr().
1183
1184Python/C API
1185
1186- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1187 that's already in the dictionary during a PyDict_Next() iteration.
1188 This used to fail occasionally when a dictionary resize operation
1189 could be triggered that would rehash all the keys. All other
1190 modifications to the dictionary are still off-limits during a
1191 PyDict_Next() iteration!
1192
1193- New extended APIs related to passing compiler variables around.
1194
1195- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1196 implement isinstance() and issubclass().
1197
1198- Py_BuildValue() now has a "D" conversion to create a Python complex
1199 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001200
Fred Drake4e262a92001-03-22 18:26:47 +00001201- Extensions types which support weak references must now set the
1202 field allocated for the weak reference machinery to NULL themselves;
1203 this is done to avoid the cost of checking each object for having a
1204 weakly referencable type in PyObject_INIT(), since most types are
1205 not weakly referencable.
1206
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001207- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1208 free variables and cell variables to and from the frame's f_locals.
1209
1210- Variants of several functions defined in pythonrun.h have been added
1211 to support the nested_scopes future statement. The variants all end
1212 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1213 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1214 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001215 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001216
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001217Distutils
1218
1219- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1220 into the release tree.
1221
Tim Peters0e57abf2001-05-02 07:39:38 +00001222- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001223 (an uninstaller, more customization of the installer's display)
1224
1225- from Jack Jansen: added Mac-specific code to generate a dialog for
1226 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001227 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001228 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001229
1230- added 'platforms' and 'keywords' to the set of metadata that can be
1231 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001232
1233- applied patches from Jason Tishler to make the compiler class work with
1234 Cygwin.
1235
1236
Tim Peters2fe289a2001-03-01 22:19:38 +00001237What's New in Python 2.1 beta 1?
1238================================
Tim Petersd66595f2001-02-04 03:09:53 +00001239
1240Core language, builtins, and interpreter
1241
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001242- Following an outcry from the community about the amount of code
1243 broken by the nested scopes feature introduced in 2.1a2, we decided
1244 to make this feature optional, and to wait until Python 2.2 (or at
1245 least 6 months) to make it standard. The option can be enabled on a
1246 per-module basis by adding "from __future__ import nested_scopes" at
1247 the beginning of a module (before any other statements, but after
1248 comments and an optional docstring). See PEP 236 (Back to the
1249 __future__) for a description of the __future__ statement. PEP 227
1250 (Statically Nested Scopes) has been updated to reflect this change,
1251 and to clarify the semantics in a number of endcases.
1252
1253- The nested scopes code, when enabled, has been hardened, and most
1254 bugs and memory leaks in it have been fixed.
1255
1256- Compile-time warnings are now generated for a number of conditions
1257 that will break or change in meaning when nested scopes are enabled:
1258
1259 - Using "from...import *" or "exec" without in-clause in a function
1260 scope that also defines a lambda or nested function with one or
1261 more free (non-local) variables. The presence of the import* or
1262 bare exec makes it impossible for the compiler to determine the
1263 exact set of local variables in the outer scope, which makes it
1264 impossible to determine the bindings for free variables in the
1265 inner scope. To avoid the warning about import *, change it into
1266 an import of explicitly name object, or move the import* statement
1267 to the global scope; to avoid the warning about bare exec, use
1268 exec...in... (a good idea anyway -- there's a possibility that
1269 bare exec will be deprecated in the future).
1270
1271 - Use of a global variable in a nested scope with the same name as a
1272 local variable in a surrounding scope. This will change in
1273 meaning with nested scopes: the name in the inner scope will
1274 reference the variable in the outer scope rather than the global
1275 of the same name. To avoid the warning, either rename the outer
1276 variable, or use a global statement in the inner function.
1277
Neil Schemenauera35c6882001-02-27 04:45:05 +00001278- An optional object allocator has been included. This allocator is
1279 optimized for Python objects and should be faster and use less memory
1280 than the standard system allocator. It is not enabled by default
1281 because of possible thread safety problems. The allocator is only
1282 protected by the Python interpreter lock and it is possible that some
1283 extension modules require a thread safe allocator. The object
1284 allocator can be enabled by providing the "--with-pymalloc" option to
1285 configure.
1286
Tim Petersd66595f2001-02-04 03:09:53 +00001287Standard library
1288
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001289- pyexpat now detects the expat version if expat.h defines it. A
1290 number of additional handlers are provided, which are only available
1291 since expat 1.95. In addition, the methods SetParamEntityParsing and
1292 GetInputContext of Parser objects are available with 1.95.x
1293 only. Parser objects now provide the ordered_attributes and
1294 specified_attributes attributes. A new module expat.model was added,
1295 which offers a number of additional constants if 1.95.x is used.
1296
1297- xml.dom offers the new functions registerDOMImplementation and
1298 getDOMImplementation.
1299
1300- xml.dom.minidom offers a toprettyxml method. A number of DOM
1301 conformance issues have been resolved. In particular, Element now
1302 has an hasAttributes method, and the handling of namespaces was
1303 improved.
1304
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001305- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1306 getting information about live Python code, and pydoc.py, a module
1307 for interactively converting docstrings to HTML or text.
1308 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001309 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001310 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1311 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001312
Tim Peters1eff7962001-03-01 02:31:33 +00001313- New library module difflib.py, primarily packaging the SequenceMatcher
1314 class at the heart of the popular ndiff.py file-comparison tool.
1315
1316- doctest.py (a framework for verifying Python code examples in docstrings)
1317 is now part of the std library.
1318
Tim Petersd66595f2001-02-04 03:09:53 +00001319Windows changes
1320
Guido van Rossume3955a82001-03-02 14:05:59 +00001321- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1322 small GUI that lets you browse the module docstrings using your
1323 default web browser.
1324
Tim Peters1eff7962001-03-01 02:31:33 +00001325- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1326 Platforms) is implemented. See
1327
1328 http://python.sourceforge.net/peps/pep-0235.html
1329
1330 for full details, especially the "Current Lower-Left Semantics" section.
1331 The new Windows import rules are simpler than before:
1332
1333 A. If the PYTHONCASEOK environment variable exists, same as
1334 before: silently accept the first case-insensitive match of any
1335 kind; raise ImportError if none found.
1336
1337 B. Else search sys.path for the first case-sensitive match; raise
1338 ImportError if none found.
1339
1340 The same rules have been implented on other platforms with case-
1341 insensitive but case-preserving filesystems too (including Cygwin, and
1342 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001343
Tim Peters25a9ce32001-02-19 07:06:36 +00001344- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1345 what it's supposed to do (and does do under NT and 2000) via direct
1346 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001347 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001348 all Win9x systems before.
1349
Tim Peters1eff7962001-03-01 02:31:33 +00001350- Build: Subproject _test (effectively) renamed to _testcapi.
1351
Tim Peters2fe289a2001-03-01 22:19:38 +00001352New platforms
1353
1354- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1355 Thanks to Steven Majewski!
1356
1357- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1358 Tishler!
1359
Guido van Rossum9089b272001-03-02 06:49:50 +00001360- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1361 Schwertberger! See RISCOS/README for more information -- it seems
1362 that because of the bizarre filename conventions on RISCOS, no port
1363 to that platform is easy. Note that the new variable os.endsep is
1364 silently supported in order to make life easier on this platform,
1365 but we don't advertise it because it's not worth for most folks to
1366 care about RISCOS portability.
1367
Tim Peters25a9ce32001-02-19 07:06:36 +00001368
Tim Petersd7b5e882001-01-25 03:36:26 +00001369What's New in Python 2.1 alpha 2?
1370=================================
Tim Peters40ead762001-01-27 05:35:26 +00001371
Tim Petersd7b5e882001-01-25 03:36:26 +00001372Core language, builtins, and interpreter
1373
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001374- Scopes nest. If a name is used in a function or class, but is not
1375 local, the definition in the nearest enclosing function scope will
1376 be used. One consequence of this change is that lambda statements
1377 could reference variables in the namespaces where the lambda is
1378 defined. In some unusual cases, this change will break code.
1379
1380 In all previous version of Python, names were resolved in exactly
1381 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001382 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001383 function A is defined within a function B, the names bound in B are
1384 not visible in A. The new rules make names bound in B visible in A,
1385 unless A contains a name binding that hides the binding in B.
1386
1387 Section 4.1 of the reference manual describes the new scoping rules
1388 in detail. The test script in Lib/test/test_scope.py demonstrates
1389 some of the effects of the change.
1390
1391 The new rules will cause existing code to break if it defines nested
1392 functions where an outer function has local variables with the same
1393 name as globals or builtins used by the inner function. Example:
1394
1395 def munge(str):
1396 def helper(x):
1397 return str(x)
1398 if type(str) != type(''):
1399 str = helper(str)
1400 return str.strip()
1401
1402 Under the old rules, the name str in helper() is bound to the
1403 builtin function str(). Under the new rules, it will be bound to
1404 the argument named str and an error will occur when helper() is
1405 called.
1406
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001407- The compiler will report a SyntaxError if "from ... import *" occurs
1408 in a function or class scope. The language reference has documented
1409 that this case is illegal, but the compiler never checked for it.
1410 The recent introduction of nested scope makes the meaning of this
1411 form of name binding ambiguous. In a future release, the compiler
1412 may allow this form when there is no possibility of ambiguity.
1413
Tim Peters40ead762001-01-27 05:35:26 +00001414- repr(string) is easier to read, now using hex escapes instead of octal,
1415 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1416
1417 >>> "\texample \r\n" + chr(0) + chr(255)
1418 '\texample \r\n\x00\xff' # in 2.1
1419 '\011example \015\012\000\377' # in 2.0
1420
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001421- Functions are now compared and hashed by identity, not by value, since
1422 the func_code attribute is writable.
1423
Fred Drakefb9d7122001-02-01 20:00:40 +00001424- Weak references (PEP 205) have been added. This involves a few
1425 changes in the core, an extension module (_weakref), and a Python
1426 module (weakref). The weakref module is the public interface. It
1427 includes support for "explicit" weak references, proxy objects, and
1428 mappings with weakly held values.
1429
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001430- A 'continue' statement can now appear in a try block within the body
1431 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001432 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001433
Tim Petersd7b5e882001-01-25 03:36:26 +00001434Standard library
1435
Barry Warsaw30dbd142001-01-31 22:14:01 +00001436- mailbox.py now has a new class, PortableUnixMailbox which is
1437 identical to UnixMailbox but uses a more portable scheme for
1438 determining From_ separators. Also, the constructors for all the
1439 classes in this module have a new optional `factory' argument, which
1440 is a callable used when new message classes must be instantiated by
1441 the next() method.
1442
Tim Petersd7b5e882001-01-25 03:36:26 +00001443- random.py is now self-contained, and offers all the functionality of
1444 the now-deprecated whrandom.py. See the docs for details. random.py
1445 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001446 and restoring the internal state of the generator; and jumpahead(n),
1447 for quickly forcing the internal state to be the same as if n calls to
1448 random() had been made. The latter is particularly useful for multi-
1449 threaded programs, creating one instance of the random.Random() class for
1450 each thread, then using .jumpahead() to force each instance to use a
1451 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001452
Tim Peters0de88fc2001-02-01 04:59:18 +00001453- random.py's seed() function is new. For bit-for-bit compatibility with
1454 prior releases, use the whseed function instead. The new seed function
1455 addresses two problems: (1) The old function couldn't produce more than
1456 about 2**24 distinct internal states; the new one about 2**45 (the best
1457 that can be done in the Wichmann-Hill generator). (2) The old function
1458 sometimes produced identical internal states when passed distinct
1459 integers, and there was no simple way to predict when that would happen;
1460 the new one guarantees to produce distinct internal states for all
1461 arguments in [0, 27814431486576L).
1462
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001463- The socket module now supports raw packets on Linux. The socket
1464 family is AF_PACKET.
1465
Tim Peters9ea17ac2001-02-02 05:57:15 +00001466- test_capi.py is a start at running tests of the Python C API. The tests
1467 are implemented by the new Modules/_testmodule.c.
1468
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001469- A new extension module, _symtable, provides provisional access to the
1470 internal symbol table used by the Python compiler. A higher-level
1471 interface will be added on top of _symtable in a future release.
1472
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001473- Removed the obsolete soundex module.
1474
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001475- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1476 the isSameNode method; NamedNodeMap the get method.
1477
1478- xml.sax.expatreader supports the lexical handler property; it
1479 generates comment, startCDATA, and endCDATA events.
1480
Tim Petersee826f82001-01-31 19:39:44 +00001481Windows changes
1482
1483- Build procedure: the zlib project is built in a different way that
1484 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001485 the zlib binary used. See PCbuild\readme.txt for details. Your old
1486 zlib-related directories can be deleted; you'll need to download fresh
1487 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001488
Tim Peters9ea17ac2001-02-02 05:57:15 +00001489- Build: New subproject _test for the benefit of test_capi.py (see above).
1490
Tim Petersb16c56f2001-02-02 21:24:51 +00001491- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1492 interface to some Python compiler internals).
1493
1494- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001495 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001496
Tim Petersa3a3a032000-11-30 05:22:44 +00001497What's New in Python 2.1 alpha 1?
1498=================================
1499
1500Core language, builtins, and interpreter
1501
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001502- There is a new Unicode companion to the PyObject_Str() API
1503 called PyObject_Unicode(). It behaves in the same way as the
1504 former, but assures that the returned value is an Unicode object
1505 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001506
Guido van Rossumf98eda02001-01-17 15:54:45 +00001507- The comparison operators support "rich comparison overloading" (PEP
1508 207). C extension types can provide a rich comparison function in
1509 the new tp_richcompare slot in the type object. The cmp() function
1510 and the C function PyObject_Compare() first try the new rich
1511 comparison operators before trying the old 3-way comparison. There
1512 is also a new C API PyObject_RichCompare() (which also falls back on
1513 the old 3-way comparison, but does not constrain the outcome of the
1514 rich comparison to a Boolean result).
1515
1516 The rich comparison function takes two objects (at least one of
1517 which is guaranteed to have the type that provided the function) and
1518 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1519 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1520 object, which may be NotImplemented (in which case the tp_compare
1521 slot function is used as a fallback, if defined).
1522
1523 Classes can overload individual comparison operators by defining one
1524 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001525 __ge__. There are no explicit "reflected argument" versions of
1526 these; instead, __lt__ and __gt__ are each other's reflection,
1527 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1528 reflection (similar at the C level). No other implications are
1529 made; in particular, Python does not assume that == is the Boolean
1530 inverse of !=, or that < is the Boolean inverse of >=. This makes
1531 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001532
1533 Classes or types that want to implement (in)equality tests but not
1534 the ordering operators (i.e. unordered types) should implement ==
1535 and !=, and raise an error for the ordering operators.
1536
Guido van Rossuma88479f2001-01-18 14:28:08 +00001537 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001538 Boolean; e.g. a matrix type might want to return a matrix of bits
1539 for A < B, giving elementwise comparisons. Such types should ensure
1540 that any interpretation of their value in a Boolean context raises
1541 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1542 at the C level) to always raise an exception.
1543
Guido van Rossuma88479f2001-01-18 14:28:08 +00001544- Complex numbers use rich comparisons to define == and != but raise
1545 an exception for <, <=, > and >=. Unfortunately, this also means
1546 that cmp() of two complex numbers raises an exception when the two
1547 numbers differ. Since it is not mathematically meaningful to compare
1548 complex numbers except for equality, I hope that this doesn't break
1549 too much code.
1550
Tim Peters3389f192001-02-18 08:48:49 +00001551- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001552 not defined by the language, other than that it's arbitrary but
1553 consistent (see the Reference Manual). An implementation detail changed
1554 in 2.1a1 such that None now compares less than any other object. Code
1555 relying on this new behavior (like code that relied on the previous
1556 behavior) does so at its own risk.
1557
Barry Warsaw573b5412001-01-15 20:43:18 +00001558- Functions and methods now support getting and setting arbitrarily
1559 named attributes (PEP 232). Functions have a new __dict__
1560 (a.k.a. func_dict) which hold the function attributes. Methods get
1561 and set attributes on their underlying im_func. It is a TypeError
1562 to set an attribute on a bound method.
1563
Guido van Rossum051e3352001-01-15 19:11:10 +00001564- The xrange() object implementation has been improved so that
1565 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1566 limitation that in this case len(xrange(sys.maxint)) can't be
1567 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1568 work fine as long as the index i doesn't actually reach 2**31.
1569 (Python uses regular ints for sequence and string indices; fixing
1570 that is much more work.)
1571
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001572- Two changes to from...import:
1573
Guido van Rossumba381232001-02-03 15:06:40 +00001574 1) "from M import X" now works even if (after loading module M)
1575 sys.modules['M'] is not a real module; it's basically a getattr()
1576 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001577
1578 2) "from M import *" now looks for M.__all__ to decide which names to
1579 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1580 filters out names starting with '_' as before. Whether or not
1581 __all__ exists, there's no restriction on the type of M.
1582
Guido van Rossumf61f1662001-01-10 20:13:55 +00001583- File objects have a new method, xreadlines(). This is the fastest
1584 way to iterate over all lines in a file:
1585
1586 for line in file.xreadlines():
1587 ...do something to line...
1588
1589 See the xreadlines module (mentioned below) for how to do this for
1590 other file-like objects.
1591
1592- Even if you don't use file.xreadlines(), you may expect a speedup on
1593 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001594 quite a bit in platform-specific ways: on systems (like Linux) that
1595 support flockfile(), getc_unlocked(), and funlockfile(), those are
1596 used by default. On systems (like Windows) without getc_unlocked(),
1597 a complicated (but still thread-safe) method using fgets() is used by
1598 default.
1599
Tim Petersd52269b2001-01-25 06:23:18 +00001600 You can force use of the fgets() method by #define'ing
1601 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001602 getc_unlocked()).
1603
Tim Petersd52269b2001-01-25 06:23:18 +00001604 You can force fgets() not to be used by #define'ing
1605 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001606 test_bufio.py fails -- and let us know if it does!).
1607
1608- In addition, the fileinput module, while still slower than the other
1609 methods on most platforms, has been sped up too, by using
1610 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001611
1612- Support for run-time warnings has been added, including a new
1613 command line option (-W) to specify the disposition of warnings.
1614 See the description of the warnings module below.
1615
1616- Extensive changes have been made to the coercion code. This mostly
1617 affects extension modules (which can now implement mixed-type
1618 numerical operators without having to use coercion), but
1619 occasionally, in boundary cases the coercion semantics have changed
1620 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001621 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001622 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001623 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001624
Guido van Rossumf98eda02001-01-17 15:54:45 +00001625- In connection with the coercion changes, a new built-in singleton
1626 object, NotImplemented is defined. This can be returned for
1627 operations that wish to indicate they are not implemented for a
1628 particular combination of arguments. From C, this is
1629 Py_NotImplemented.
1630
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001631- The interpreter accepts now bytecode files on the command line even
1632 if they do not have a .pyc or .pyo extension. On Linux, after executing
1633
Martin v. Löwise214baa2001-02-04 22:37:56 +00001634import imp,sys,string
1635magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1636reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1637open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001638
1639 any byte code file can be used as an executable (i.e. as an argument
1640 to execve(2)).
1641
Tim Peters9940b802000-12-01 07:59:35 +00001642- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001643 character. In 1.6 and earlier, they never produced a sign,
1644 and raised an error if the value of the long was too large
1645 to fit in a Python int. In 2.0, they produced a sign if and
1646 only if too large to fit in an int. This was inconsistent
1647 across platforms (because the size of an int varies across
1648 platforms), and inconsistent with hex() and oct(). Example:
1649
1650 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001651 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001652 'ffffffbe' # in 2.0 and before, on 32-bit machines
1653 >>> hex(-0x42L)
1654 '-0x42L' # in all versions of Python
1655
Tim Peters9940b802000-12-01 07:59:35 +00001656 The behavior of %d formats for negative Python longs remains
1657 the same as in 2.0 (although in 1.6 and before, they raised
1658 an error if the long didn't fit in a Python int).
1659
1660 %u formats don't make sense for Python longs, but are allowed
1661 and treated the same as %d in 2.1. In 2.0, a negative long
1662 formatted via %u produced a sign if and only if too large to
1663 fit in an int. In 1.6 and earlier, a negative long formatted
1664 via %u raised an error if it was too big to fit in an int.
1665
Guido van Rossum3661d392000-12-12 22:10:31 +00001666- Dictionary objects have an odd new method, popitem(). This removes
1667 an arbitrary item from the dictionary and returns it (in the form of
1668 a (key, value) pair). This can be useful for algorithms that use a
1669 dictionary as a bag of "to do" items and repeatedly need to pick one
1670 item. Such algorithms normally end up running in quadratic time;
1671 using popitem() they can usually be made to run in linear time.
1672
Tim Peters36cdad12000-12-29 02:06:45 +00001673Standard library
1674
Thomas Woutersfe385252001-01-19 23:16:56 +00001675- In the time module, the time argument to the functions strftime,
1676 localtime, gmtime, asctime and ctime is now optional, defaulting to
1677 the current time (in the local timezone).
1678
Guido van Rossumda91f222001-01-15 16:36:08 +00001679- The ftplib module now defaults to passive mode, which is deemed a
1680 more useful default given that clients are often inside firewalls
1681 these days. Note that this could break if ftplib is used to connect
1682 to a *server* that is inside a firewall, from outside; this is
1683 expected to be a very rare situation. To fix that, you can call
1684 ftp.set_pasv(0).
1685
Martin v. Löwis10a27872001-01-13 09:54:41 +00001686- The module site now treats .pth files not only for path configuration,
1687 but also supports extensions to the initialization code: Lines starting
1688 with import are executed.
1689
Guido van Rossumf61f1662001-01-10 20:13:55 +00001690- There's a new module, warnings, which implements a mechanism for
1691 issuing and filtering warnings. There are some new built-in
1692 exceptions that serve as warning categories, and a new command line
1693 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1694 turns warnings into errors). warnings.warn(message[, category])
1695 issues a warning message; this can also be called from C as
1696 PyErr_Warn(category, message).
1697
1698- A new module xreadlines was added. This exports a single factory
1699 function, xreadlines(). The intention is that this code is the
1700 absolutely fastest way to iterate over all lines in an open
1701 file(-like) object:
1702
1703 import xreadlines
1704 for line in xreadlines.xreadlines(file):
1705 ...do something to line...
1706
1707 This is equivalent to the previous the speed record holder using
1708 file.readlines(sizehint). Note that if file is a real file object
1709 (as opposed to a file-like object), this is equivalent:
1710
1711 for line in file.xreadlines():
1712 ...do something to line...
1713
Tim Peters36cdad12000-12-29 02:06:45 +00001714- The bisect module has new functions bisect_left, insort_left,
1715 bisect_right and insort_right. The old names bisect and insort
1716 are now aliases for bisect_right and insort_right. XXX_right
1717 and XXX_left methods differ in what happens when the new element
1718 compares equal to one or more elements already in the list: the
1719 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001720 right. Code that doesn't care where equal elements end up should
1721 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001722
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001723- The new curses.panel module wraps the panel library that forms part
1724 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1725
Guido van Rossumf61f1662001-01-10 20:13:55 +00001726- The SocketServer module now sets the allow_reuse_address flag by
1727 default in the TCPServer class.
1728
1729- A new function, sys._getframe(), returns the stack frame pointer of
1730 the caller. This is intended only as a building block for
1731 higher-level mechanisms such as string interpolation.
1732
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001733- The pyexpat module supports a number of new handlers, which are
1734 available only in expat 1.2. If invocation of a callback fails, it
1735 will report an additional frame in the traceback. Parser objects
1736 participate now in garbage collection. If expat reports an unknown
1737 encoding, pyexpat will try to use a Python codec; that works only
1738 for single-byte charsets. The parser type objects is exposed as
1739 XMLParserObject.
1740
1741- xml.dom now offers standard definitions for symbolic node type and
1742 exception code constants, and a hierarchy of DOM exceptions. minidom
1743 was adjusted to use them.
1744
1745- The conformance of xml.dom.minidom to the DOM specification was
1746 improved. It detects a number of additional error cases; the
1747 previous/next relationship works even when the tree is modified;
1748 Node supports the normalize() method; NamedNodeMap, DocumentType and
1749 DOMImplementation classes were added; Element supports the
1750 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1751 method.
1752
Guido van Rossumf61f1662001-01-10 20:13:55 +00001753Build issues
1754
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001755- For Unix (and Unix-compatible) builds, configuration and building of
1756 extension modules is now greatly automated. Rather than having to
1757 edit the Modules/Setup file to indicate which modules should be
1758 built and where their include files and libraries are, a
1759 distutils-based setup.py script now takes care of building most
1760 extension modules. All extension modules built this way are built
1761 as shared libraries. Only a few modules that must be linked
1762 statically are still listed in the Setup file; you won't need to
1763 edit their configuration.
1764
1765- Python should now build out of the box on Cygwin. If it doesn't,
1766 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001767
1768- Python now always uses its own (renamed) implementation of getopt()
1769 -- there's too much variation among C library getopt()
1770 implementations.
1771
1772- C++ compilers are better supported; the CXX macro is always set to a
1773 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001774
Tim Petersd92dfe02000-12-12 01:18:41 +00001775Windows changes
1776
1777- select module: By default under Windows, a select() call
1778 can specify no more than 64 sockets. Python now boosts
1779 this Microsoft default to 512. If you need even more than
1780 that, see the MS docs (you'll need to #define FD_SETSIZE
1781 and recompile Python from source).
1782
Guido van Rossumf61f1662001-01-10 20:13:55 +00001783- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1784 subdirectory is no more!
1785
Tim Petersa3a3a032000-11-30 05:22:44 +00001786
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001787What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001788=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001789
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001790Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001791changes are in the file HISTORY. If you are making the jump directly
1792from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1793HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001794
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001795Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1796the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1797http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001798
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001799--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001800
1801======================================================================
1802
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001803What's new in 2.0 (since release candidate 1)?
1804==============================================
1805
1806Standard library
1807
1808- The copy_reg module was modified to clarify its intended use: to
1809 register pickle support for extension types, not for classes.
1810 pickle() will raise a TypeError if it is passed a class.
1811
1812- Fixed a bug in gettext's "normalize and expand" code that prevented
1813 it from finding an existing .mo file.
1814
1815- Restored support for HTTP/0.9 servers in httplib.
1816
Tim Peters989b7b92000-10-16 20:24:53 +00001817- The math module was changed to stop raising OverflowError in case of
1818 underflow, and return 0 instead in underflow cases. Whether Python
1819 used to raise OverflowError in case of underflow was platform-
1820 dependent (it did when the platform math library set errno to ERANGE
1821 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001822
1823- Fixed a bug in StringIO that occurred when the file position was not
1824 at the end of the file and write() was called with enough data to
1825 extend past the end of the file.
1826
1827- Fixed a bug that caused Tkinter error messages to get lost on
1828 Windows. The bug was fixed by replacing direct use of
1829 interp->result with Tcl_GetStringResult(interp).
1830
1831- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1832 redirect response.
1833
1834- Several changes were made to distutils: Some debugging code was
1835 removed from util. Fixed the installer used when an external zip
1836 program (like WinZip) is not found; the source code for this
1837 installer is in Misc/distutils. check_lib() was modified to behave
1838 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1839 test for whether installed modules are on sys.path was changed to
1840 use both normcase() and normpath().
1841
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001842- Several minor bugs were fixed in the xml package (the minidom,
1843 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001844
1845- The regression test driver (regrtest.py) behavior when invoked with
1846 -l changed: It now reports a count of objects that are recognized as
1847 garbage but not freed by the garbage collector.
1848
Tim Peters989b7b92000-10-16 20:24:53 +00001849- The regression test for the math module was changed to test
1850 exceptional behavior when the test is run in verbose mode. Python
1851 cannot yet guarantee consistent exception behavior across platforms,
1852 so the exception part of test_math is run only in verbose mode, and
1853 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001854
1855Internals
1856
1857- PyOS_CheckStack() has been disabled on Win64, where it caused
1858 test_sre to fail.
1859
1860Build issues
1861
1862- Changed compiler flags, so that gcc is always invoked with -Wall and
1863 -Wstrict-prototypes. Users compiling Python with GCC should see
1864 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001865 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001866 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001867
Tim Petersa3a3a032000-11-30 05:22:44 +00001868- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001869
1870Tools and other miscellany
1871
1872- The compiler in Tools/compiler was updated to support the new
1873 language features introduced in 2.0: extended print statement, list
1874 comprehensions, and augmented assignments. The new compiler should
1875 also be backwards compatible with Python 1.5.2; the compiler will
1876 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001877 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001878
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001879What's new in 2.0 release candidate 1 (since beta 2)?
1880=====================================================
1881
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001882What is release candidate 1?
1883
1884We believe that release candidate 1 will fix all known bugs that we
1885intend to fix for the 2.0 final release. This release should be a bit
1886more stable than the previous betas. We would like to see even more
1887widespread testing before the final release, so we are producing this
1888release candidate. The final release will be exactly the same unless
1889any show-stopping (or brown bag) bugs are found by testers of the
1890release candidate.
1891
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001892All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001893to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001894
1895Core language, builtins, and interpreter
1896
1897- A bug that caused crashes when __coerce__ was used with augmented
1898 assignment, e.g. +=, was fixed.
1899
1900- Raise ZeroDivisionError when raising zero to a negative number,
1901 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1902 power operator and the result of math.pow(0.0, -2.0) will vary by
1903 platform. On Linux, it raises a ValueError.
1904
1905- A bug in Unicode string interpolation was fixed that occasionally
1906 caused errors with formats including "%%". For example, the
1907 following expression "%% %s" % u"abc" no longer raises a TypeError.
1908
1909- Compilation of deeply nested expressions raises MemoryError instead
1910 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1911
1912- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1913 rendering them useless. They are now written in binary mode again.
1914
1915Standard library
1916
1917- Keyword arguments are now accepted for most pattern and match object
1918 methods in SRE, the standard regular expression engine.
1919
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001920- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001921 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001922
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001923- Several bugs in the Unicode handling and error handling in _tkinter
1924 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001925
1926- Fix memory management errors in Merge() and Tkapp_Call() routines.
1927
1928- Several changes were made to cStringIO to make it compatible with
1929 the file-like object interface and with StringIO. If operations are
1930 performed on a closed object, an exception is raised. The truncate
1931 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001932 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001933
1934- There were many changes made to the linuxaudiodev module and its
1935 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001936 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001937
1938 Note that this module is named poorly, because it should work
1939 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001940 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001941
1942 The module now raises exceptions when errors occur instead of
1943 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1944 audio) and defines a getptr() method that calls the
1945 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1946
1947- The library_version attribute, introduced in an earlier beta, was
1948 removed because it can not be supported with early versions of the C
1949 readline library, which provides no way to determine the version at
1950 compile-time.
1951
1952- The binascii module is now enabled on Win64.
1953
Tim Peters46446d62000-10-09 21:19:31 +00001954- tokenize.py no longer suffers "recursion depth" errors when parsing
1955 programs with very long string literals.
1956
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001957Internals
1958
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001959- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001960 which is called when the interpreter starts up to determine where
1961 the standard library is installed. These vulnerabilities affect all
1962 previous versions of Python and can be exploited by setting very
1963 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1964 setuid Python script, although use of the wrapper in
1965 Misc/setuid-prog.c will eliminate the vulnerability.
1966
1967- Fixed garbage collection bugs in instance creation that were
1968 triggered when errors occurred during initialization. The solution,
1969 applied in cPickle and in PyInstance_New(), is to call
1970 PyObject_GC_Init() after the initialization of the object's
1971 container attributes is complete.
1972
1973- pyexpat adds definitions of PyModule_AddStringConstant and
1974 PyModule_AddObject if the Python version is less than 2.0, which
1975 provides compatibility with PyXML on Python 1.5.2.
1976
1977- If the platform has a bogus definition for LONG_BIT (the number of
1978 bits in a long), an error will be reported at compile time.
1979
1980- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1981 collection crashes and possibly other, unreported crashes.
1982
1983- Fixed a memory leak in _PyUnicode_Fini().
1984
1985Build issues
1986
1987- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001988 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001989 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001990
1991- The mmap.PAGESIZE constant is now initialized using sysconf when
1992 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1993
1994- The md5 file should now compile on all platforms.
1995
1996- The select module now compiles on platforms that do not define
1997 POLLRDNORM and related constants.
1998
1999- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002000 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002001
Jeremy Hylton10921202000-10-09 18:34:12 +00002002- BeOS: A number of changes were made to the build and installation
2003 process. ar-fake now operates on a directory of object files.
2004 dl_export.h is gone, and its macros now appear on the mwcc command
2005 line during build on PPC BeOS.
2006
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002007- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002008 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002009
2010- Cygwin: Support for shared libraries, Tkinter, and sockets.
2011
2012- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2013
2014Tools and other miscellany
2015
2016- Removed debugging prints from main used with freeze.
2017
Tim Peters46446d62000-10-09 21:19:31 +00002018- IDLE auto-indent no longer crashes when it encounters Unicode
2019 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002020
2021What's new in 2.0 beta 2 (since beta 1)?
2022========================================
2023
2024Core language, builtins, and interpreter
2025
Tim Peters482c0212000-09-26 06:33:09 +00002026- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002027 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002028
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002029- Add -h and -V command line options to print the usage message and
2030 Python version number and exit immediately.
2031
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002032- eval() and exec accept Unicode objects as code parameters.
2033
2034- getattr() and setattr() now also accept Unicode objects for the
2035 attribute name, which are converted to strings using the default
2036 encoding before lookup.
2037
2038- Multiplication on string and Unicode now does proper bounds
2039 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2040 string is too long."
2041
2042- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002043 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002044
Jeremy Hylton1b618592000-09-26 05:32:36 +00002045
2046Standard library and extensions
2047
Guido van Rossum5b08f132001-04-16 02:05:23 +00002048- socket module: the OpenSSL code now adds support for RAND_status()
2049 and EGD (Entropy Gathering Device).
2050
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002051- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002052 argument checking; it still takes no arguments.
2053
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002054- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002055
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002056- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002057
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002058- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002059
2060- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002061 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002062
2063- copy: Copy Unicode objects atomically.
2064
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002065- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002066
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002067- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002068
Fred Drake67233bc2000-09-26 16:40:27 +00002069- dbm: Add get() and setdefault() methods to dbm object. Add constant
2070 `library' to module that names the library used. Added doc strings
2071 and method names to error messages. Uses configure to determine
2072 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2073 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002074
2075- distutils: Update to version 0.9.3.
2076
2077- dl: Add several dl.RTLD_ constants.
2078
2079- fpectl: Now supported on FreeBSD.
2080
2081- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2082 found by the collector will be saved in gc.garbage. This is useful
2083 for debugging a program that creates reference cycles.
2084
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002085- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002086 of HTTP class. Do not close socket on zero-length response. Do not
2087 crash when server sends invalid content-length header.
2088
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002089- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002090
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002091- marshal: When reading a short, sign-extend on platforms where shorts
2092 are bigger than 16 bits. When reading a long, repair the unportable
2093 sign extension that was being done for 64-bit machines. (It assumed
2094 that signed right shift sign-extends.)
2095
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002096- operator: Add contains(), invert(), __invert__() as aliases for
2097 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002098
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002099- os: Add support for popen2() and popen3() on all platforms where
2100 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002101
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002102- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002103 clicking on a file in Explorer (or passing the file name to the
2104 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002105
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002106- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002107 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002108
2109- pickle: Now raises ValueError when an invalid pickle that contains
2110 a non-string repr where a string repr was expected. This behavior
2111 matches cPickle.
2112
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002113- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002114
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002115- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002116
2117- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002118 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002119 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002120
2121- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002122 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002123
2124- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002125 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002126 few cycles during startup since the first call to
2127 setdefaultencoding() will initialize the codec registry and the
2128 encodings package.
2129
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002130- socket: Support for size hint in readlines() method of object returned
2131 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002132
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002133- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002134 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002135 is followed by whitespace.
2136
Tim Petersa3a3a032000-11-30 05:22:44 +00002137- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002138
2139- struct: Check ranges for bytes and shorts.
2140
2141- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002142 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002143
2144- Tkinter: Image objects are now guaranteed to have unique ids. Set
2145 event.delta to zero if Tk version doesn't support mousewheel.
2146 Removed some debugging prints.
2147
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002148- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002149
Fred Drake67233bc2000-09-26 16:40:27 +00002150- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002151 which works around a bug in Norton AntiVirus 2000 that leads directly
2152 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002153
2154- xml: New version detection code allows PyXML to override standard
2155 XML package if PyXML version is greater than 0.6.1.
2156
Fred Drake64bb3802000-09-26 16:21:35 +00002157- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2158 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2159 tree only for nodes which are sufficiently interesting to a specific
2160 application. Does not provide the HTML-specific extensions. Still
2161 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002162
Fred Drake64bb3802000-09-26 16:21:35 +00002163- xml.sax: SAX 2 support for Python, including all the handler
2164 interfaces needed to process XML 1.0 compliant XML. Some
2165 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002166
Fred Drake64bb3802000-09-26 16:21:35 +00002167- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2168 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002169
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002170
Jeremy Hylton1b618592000-09-26 05:32:36 +00002171C API
2172
2173- Add three new convenience functions for module initialization --
2174 PyModule_AddObject(), PyModule_AddIntConstant(), and
2175 PyModule_AddStringConstant().
2176
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002177- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002178 removed and add #error to Python.h if NULL isn't defined after
2179 #include of stdio.h.
2180
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002181- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002182 backwards compatibility (at the source level) with old extensions.
2183
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002184- A wrapper API was added for signal() and sigaction(). Instead of
2185 either function, always use PyOS_getsig() to get a signal handler
2186 and PyOS_setsig() to set one. A new convenience typedef
2187 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002188
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002189- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002190 internal data buffer and size of a string object -- or the default
2191 encoded version of a Unicode object.
2192
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002193- PyString_Size() and PyString_AsString() accept Unicode objects.
2194
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002195- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002196 exists). INT_MAX and LONG_MAX will always be defined, even if
2197 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002198
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002199- PyFloat_FromString takes a second argument, pend, that was
2200 effectively useless. It is now officially useless but preserved for
2201 backwards compatibility. If the pend argument is not NULL, *pend is
2202 set to NULL.
2203
2204- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2205 for the attribute name. See note on getattr() above.
2206
2207- A few bug fixes to argument processing for Unicode.
2208 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2209 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2210 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002211 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002212
2213- Py_BuildValue accepts B format (for bgen-generated code).
2214
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002215
Jeremy Hylton1b618592000-09-26 05:32:36 +00002216Internals
2217
2218- On Unix, fix code for finding Python installation directory so that
2219 it works when argv[0] is a relative path.
2220
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002221- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002222 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002223 rather than by generating a copy of the object.
2224
Tim Peters482c0212000-09-26 06:33:09 +00002225- Several of the internal Unicode tables are much smaller now, and
2226 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002227
Jeremy Hylton97693b02000-09-26 17:42:51 +00002228- In the garbage collector: Fixed bug in collection of tuples. Fixed
2229 bug that caused some instances to be removed from the container set
2230 while they were still live. Fixed parsing in gc.set_debug() for
2231 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002232
2233- Fixed refcount problem in instance deallocation that only occurred
2234 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2235
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002236- On Windows, getpythonregpath is now protected against null data in
2237 registry key.
2238
2239- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002240 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002241
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002242
Jeremy Hylton1b618592000-09-26 05:32:36 +00002243Build and platform-specific issues
2244
2245- Better support of GNU Pth via --with-pth configure option.
2246
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002247- Python/C API now properly exposed to dynamically-loaded extension
2248 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002249
2250- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2251 Don't define MS_SYNC to be zero when it is undefined. Added missing
2252 prototypes in posixmodule.c.
2253
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002254- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002255 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002256
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002257- Fix largefile support on older NetBSD systems and OpenBSD by adding
2258 define for TELL64.
2259
2260
2261Tools and other miscellany
2262
2263- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2264
2265- freeze: The modulefinder now works with 2.0 opcodes.
2266
Tim Petersa3a3a032000-11-30 05:22:44 +00002267- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002268 Move hackery of sys.argv until after the Tk instance has been
2269 created, which allows the application-specific Tkinter
2270 initialization to be executed if present; also pass an explicit
2271 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002272
Jeremy Hylton1b618592000-09-26 05:32:36 +00002273
2274What's new in 2.0 beta 1?
2275=========================
2276
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002277Source Incompatibilities
2278------------------------
2279
2280None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2281such as single-argument append(), connect() and bind(), and changes to
2282str(long) and repr(float).
2283
2284
2285Binary Incompatibilities
2286------------------------
2287
2288- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2289with Python 2.0; these extensions will have to be rebuilt for Python
22902.0.
2291
2292- On Windows, attempting to import a third party extension built for
2293Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2294can do about this. Check your PYTHONPATH environment variable!
2295
2296- Python bytecode files (*.pyc and *.pyo) are not compatible between
2297releases.
2298
2299
2300Overview of Changes Since 1.6
2301-----------------------------
2302
2303There are many new modules (including brand new XML support through
2304the xml package, and i18n support through the gettext module); a list
2305of all new modules is included below. Lots of bugs have been fixed.
2306
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002307The process for making major new changes to the language has changed
2308since Python 1.6. Enhancements must now be documented by a Python
2309Enhancement Proposal (PEP) before they can be accepted.
2310
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002311There are several important syntax enhancements, described in more
2312detail below:
2313
2314 - Augmented assignment, e.g. x += 1
2315
2316 - List comprehensions, e.g. [x**2 for x in range(10)]
2317
2318 - Extended import statement, e.g. import Module as Name
2319
2320 - Extended print statement, e.g. print >> file, "Hello"
2321
2322Other important changes:
2323
2324 - Optional collection of cyclical garbage
2325
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002326Python Enhancement Proposal (PEP)
2327---------------------------------
2328
2329PEP stands for Python Enhancement Proposal. A PEP is a design
2330document providing information to the Python community, or describing
2331a new feature for Python. The PEP should provide a concise technical
2332specification of the feature and a rationale for the feature.
2333
2334We intend PEPs to be the primary mechanisms for proposing new
2335features, for collecting community input on an issue, and for
2336documenting the design decisions that have gone into Python. The PEP
2337author is responsible for building consensus within the community and
2338documenting dissenting opinions.
2339
2340The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002341
2342Augmented Assignment
2343--------------------
2344
2345This must have been the most-requested feature of the past years!
2346Eleven new assignment operators were added:
2347
Guido van Rossume905e952000-09-05 12:42:46 +00002348 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002349
2350For example,
2351
2352 A += B
2353
2354is similar to
2355
2356 A = A + B
2357
2358except that A is evaluated only once (relevant when A is something
2359like dict[index].attr).
2360
2361However, if A is a mutable object, A may be modified in place. Thus,
2362if A is a number or a string, A += B has the same effect as A = A+B
2363(except A is only evaluated once); but if a is a list, A += B has the
2364same effect as A.extend(B)!
2365
2366Classes and built-in object types can override the new operators in
2367order to implement the in-place behavior; the not-in-place behavior is
2368used automatically as a fallback when an object doesn't implement the
2369in-place behavior. For classes, the method name is derived from the
2370method name for the corresponding not-in-place operator by inserting
2371an 'i' in front of the name, e.g. __iadd__ implements in-place
2372__add__.
2373
2374Augmented assignment was implemented by Thomas Wouters.
2375
2376
2377List Comprehensions
2378-------------------
2379
2380This is a flexible new notation for lists whose elements are computed
2381from another list (or lists). The simplest form is:
2382
2383 [<expression> for <variable> in <sequence>]
2384
Guido van Rossum56db0952000-09-06 23:34:25 +00002385For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002386This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002387
2388You can also add a condition:
2389
2390 [<expression> for <variable> in <sequence> if <condition>]
2391
2392For example, [w for w in words if w == w.lower()] would yield the list
2393of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002394than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002395
2396You can also have nested for loops and more than one 'if' clause. For
2397example, here's a function that flattens a sequence of sequences::
2398
2399 def flatten(seq):
2400 return [x for subseq in seq for x in subseq]
2401
2402 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2403
2404This prints
2405
2406 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2407
2408List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002409Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002410
2411
2412Extended Import Statement
2413-------------------------
2414
2415Many people have asked for a way to import a module under a different
2416name. This can be accomplished like this:
2417
2418 import foo
2419 bar = foo
2420 del foo
2421
2422but this common idiom gets old quickly. A simple extension of the
2423import statement now allows this to be written as follows:
2424
2425 import foo as bar
2426
2427There's also a variant for 'from ... import':
2428
2429 from foo import bar as spam
2430
2431This also works with packages; e.g. you can write this:
2432
2433 import test.regrtest as regrtest
2434
2435Note that 'as' is not a new keyword -- it is recognized only in this
2436context (this is only possible because the syntax for the import
2437statement doesn't involve expressions).
2438
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002439Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002440
2441
2442Extended Print Statement
2443------------------------
2444
2445Easily the most controversial new feature, this extension to the print
2446statement adds an option to make the output go to a different file
2447than the default sys.stdout.
2448
2449For example, to write an error message to sys.stderr, you can now
2450write:
2451
2452 print >> sys.stderr, "Error: bad dog!"
2453
2454As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002455evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002456
2457 print >> None, "Hello world"
2458
2459is equivalent to
2460
2461 print "Hello world"
2462
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002463Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002464
2465
2466Optional Collection of Cyclical Garbage
2467---------------------------------------
2468
2469Python is now equipped with a garbage collector that can hunt down
2470cyclical references between Python objects. It's no replacement for
2471reference counting; in fact, it depends on the reference counts being
2472correct, and decides that a set of objects belong to a cycle if all
2473their reference counts can be accounted for from their references to
2474each other. This devious scheme was first proposed by Eric Tiedemann,
2475and brought to implementation by Neil Schemenauer.
2476
2477There's a module "gc" that lets you control some parameters of the
2478garbage collection. There's also an option to the configure script
2479that lets you enable or disable the garbage collection. In 2.0b1,
2480it's on by default, so that we (hopefully) can collect decent user
2481experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002482performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002483off by default in the final 2.0 release.
2484
2485
2486Smaller Changes
2487---------------
2488
2489A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2490map(None, seq1, seq2, ...) when the sequences have the same length;
2491i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2492the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002493zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002494
2495sys.version_info is a tuple (major, minor, micro, level, serial).
2496
2497Dictionaries have an odd new method, setdefault(key, default).
2498dict.setdefault(key, default) returns dict[key] if it exists; if not,
2499it sets dict[key] to default and returns that value. Thus:
2500
2501 dict.setdefault(key, []).append(item)
2502
2503does the same work as this common idiom:
2504
2505 if not dict.has_key(key):
2506 dict[key] = []
2507 dict[key].append(item)
2508
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002509There are two new variants of SyntaxError that are raised for
2510indentation-related errors: IndentationError and TabError.
2511
2512Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2513escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002514
2515The limits on the size of expressions and file in Python source code
2516have been raised from 2**16 to 2**32. Previous versions of Python
2517were limited because the maximum argument size the Python VM accepted
2518was 2**16. This limited the size of object constructor expressions,
2519e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2520limit was raised thanks to a patch by Charles Waldman that effectively
2521fixes the problem. It is now much more likely that you will be
2522limited by available memory than by an arbitrary limit in Python.
2523
2524The interpreter's maximum recursion depth can be modified by Python
2525programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2526limit is the maximum number of recursive calls that can be made by
2527Python code. The limit exists to prevent infinite recursion from
2528overflowing the C stack and causing a core dump. The default value is
25291000. The maximum safe value for a particular platform can be found
2530by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002531
2532New Modules and Packages
2533------------------------
2534
2535atexit - for registering functions to be called when Python exits.
2536
2537imputil - Greg Stein's alternative API for writing custom import
2538hooks.
2539
2540pyexpat - an interface to the Expat XML parser, contributed by Paul
2541Prescod.
2542
2543xml - a new package with XML support code organized (so far) in three
2544subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2545would fill a volume. There's a special feature whereby a
2546user-installed package named _xmlplus overrides the standard
2547xmlpackage; this is intended to give the XML SIG a hook to distribute
2548backwards-compatible updates to the standard xml package.
2549
2550webbrowser - a platform-independent API to launch a web browser.
2551
2552
Guido van Rossume905e952000-09-05 12:42:46 +00002553Changed Modules
2554---------------
2555
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002556array -- new methods for array objects: count, extend, index, pop, and
2557remove
2558
2559binascii -- new functions b2a_hex and a2b_hex that convert between
2560binary data and its hex representation
2561
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002562calendar -- Many new functions that support features including control
2563over which day of the week is the first day, returning strings instead
2564of printing them. Also new symbolic constants for days of week,
2565e.g. MONDAY, ..., SUNDAY.
2566
2567cgi -- FieldStorage objects have a getvalue method that works like a
2568dictionary's get method and returns the value attribute of the object.
2569
2570ConfigParser -- The parser object has new methods has_option,
2571remove_section, remove_option, set, and write. They allow the module
2572to be used for writing config files as well as reading them.
2573
2574ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002575optionally support the RFC 959 REST command.
2576
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002577gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002578
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002579httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2580the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002581
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002582locale -- implement getdefaultlocale for Win32 and Macintosh
2583
2584marshal -- no longer dumps core when marshaling deeply nested or
2585recursive data structures
2586
2587os -- new functions isatty, seteuid, setegid, setreuid, setregid
2588
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002589os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2590support under Unix.
2591
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002592os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002593
2594os.path -- fix semantics of os.path.commonprefix
2595
2596smtplib -- support for sending very long messages
2597
2598socket -- new function getfqdn()
2599
2600readline -- new functions to read, write and truncate history files.
2601The readline section of the library reference manual contains an
2602example.
2603
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002604select -- add interface to poll system call
2605
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002606shutil -- new copyfileobj function
2607
2608SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2609HTTP server.
2610
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002611Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002612
2613urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002614e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002615
2616whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002617
2618
2619Obsolete Modules
2620----------------
2621
2622None. However note that 1.6 made a whole slew of modules obsolete:
2623stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2624poly, zmod, strop, util, whatsound.
2625
2626
2627Changed, New, Obsolete Tools
2628----------------------------
2629
Tim Peters8b092332000-09-05 20:15:25 +00002630None.
Guido van Rossume905e952000-09-05 12:42:46 +00002631
2632
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002633C-level Changes
2634---------------
2635
2636Several cleanup jobs were carried out throughout the source code.
2637
2638All C code was converted to ANSI C; we got rid of all uses of the
2639Py_PROTO() macro, which makes the header files a lot more readable.
2640
2641Most of the portability hacks were moved to a new header file,
2642pyport.h; several other new header files were added and some old
2643header files were removed, in an attempt to create a more rational set
2644of header files. (Few of these ever need to be included explicitly;
2645they are all included by Python.h.)
2646
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002647Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002648and Win64, especially for the new Intel Itanium processor. Mick also
2649added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002650
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002651The C APIs to return an object's size have been update to consistently
2652use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2653previous versions, the abstract interfaces used PyXXX_Length and the
2654concrete interfaces used PyXXX_Size. The old names,
2655e.g. PyObject_Length, are still available for backwards compatibility
2656at the API level, but are deprecated.
2657
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002658The PyOS_CheckStack function has been implemented on Windows by
2659Fredrik Lundh. It prevents Python from failing with a stack overflow
2660on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002661
2662The GC changes resulted in creation of two new slots on object,
2663tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002664the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002665
2666The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002667C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002668
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002669PyErr_Format has been updated to automatically calculate the size of
2670the buffer needed to hold the formatted result string. This change
2671prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002672
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002673New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002674
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002675PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2676that are the same as their non-Ex counterparts except they take an
2677extra flag argument that tells them to close the file when done.
2678
2679XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002680
Tim Peters8b092332000-09-05 20:15:25 +00002681
2682Windows Changes
2683---------------
2684
2685New popen2/popen3/peopen4 in os module (see Changed Modules above).
2686
2687os.popen is much more usable on Windows 95 and 98. See Microsoft
2688Knowledge Base article Q150956. The Win9x workaround described there
2689is implemented by the new w9xpopen.exe helper in the root of your
2690Python installation. Note that Python uses this internally; it is not
2691a standalone program.
2692
2693Administrator privileges are no longer required to install Python
2694on Windows NT or Windows 2000. If you have administrator privileges,
2695Python's registry info will be written under HKEY_LOCAL_MACHINE.
2696Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002697under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002698uses of Python, but will prevent some advanced uses from working
2699(for example, running a Python script as an NT service, or possibly
2700from CGI).
2701
2702[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2703installer; instead, it installs the needed Tcl/Tk files directly in the
2704Python directory. If you already have a Tcl/Tk installation, this
2705wastes some disk space (about 4 Megs) but avoids problems with
2706conflicting Tcl/Tk installations, and makes it much easier for Python
2707to ensure that Tcl/Tk can find all its files.
2708
2709[This was new in 1.6] The Windows installer now installs by default in
2710\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2711
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002712
2713Updates to the changes between 1.5.2 and 1.6
2714--------------------------------------------
2715
2716The 1.6 NEWS file can't be changed after the release is done, so here
2717is some late-breaking news:
2718
2719New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2720and changes to getlocale() and setlocale().
2721
2722The new module is now enabled per default.
2723
2724It is not true that the encodings codecs cannot be used for normal
2725strings: the string.encode() (which is also present on 8-bit strings
2726!) allows using them for 8-bit strings too, e.g. to convert files from
2727cp1252 (Windows) to latin-1 or vice-versa.
2728
2729Japanese codecs are available from Tamito KAJIYAMA:
2730http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2731
2732
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002733======================================================================