blob: e873dad6882c9a12b7afb5e4a9f308b27638e81f [file] [log] [blame]
Tim Peters84362bc2001-10-19 17:55:30 +00001What's New in Python 2.2b2?
2XXX Planned XXX Release date: 14-Nov-2001
3===========================
4
5Type/class unification and new-style classes
6
Tim Petersa427a2b2001-10-29 22:25:45 +00007- The new builtin dictionary() constructor, and dictionary type, have
8 been renamed to dict. This reflects a decade of common usage.
9
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +000010- New-style classes can now have a __del__ method, which is called
11 when the instance is deleted (just like for classic classes).
12
Guido van Rossum12d955c2001-10-26 14:56:06 +000013- Assignment to object.__dict__ is now possible, for objects that are
14 instances of new-style classes that have a __dict__ (unless the base
15 class forbids it).
16
Tim Peters1fc240e2001-10-26 05:06:50 +000017- dictionary() now accepts an iterable object producing 2-sequences.
18 For example, dictionary(d.items()) == d for any dictionary d. The
19 argument, and the elements of the argument, can be any iterable
20 objects.
21
Guido van Rossumc8e56452001-10-22 00:43:43 +000022- Methods of built-in types now properly check for keyword arguments
23 (formerly these were silently ignored). The only built-in methods
24 that take keyword arguments are __call__, __init__ and __new__.
25
Guido van Rossum86443212001-10-27 22:28:54 +000026- The socket function has been converted to a type; see below.
27
Tim Peters84362bc2001-10-19 17:55:30 +000028Core and builtins
29
Guido van Rossum12d955c2001-10-26 14:56:06 +000030- Clarified the error messages for unsupported operands to an operator
31 (like 1 + '').
32
Tim Peters84362bc2001-10-19 17:55:30 +000033Extension modules
34
Tim Peters169ded02001-11-03 19:57:21 +000035- By default, the gc.garbage list now contains only those instances in
36 unreachable cycles that have __del__ methods; in 2.1 it contained all
37 instances in unreachable cycles. "Instances" here has been generalized
38 to include instances of both new-style and old-style classes.
39
Guido van Rossum12d955c2001-10-26 14:56:06 +000040- The socket module defines a new method for socket objects,
41 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +000042 send() until all data has been sent. Also, the socket function has
43 been converted to a subclassable type, like list and tuple (etc.)
44 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +000045
46- Various bugfixes to the curses module. There is now a test suite
47 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000048
Guido van Rossum692adf12001-10-30 03:03:03 +000049- binascii.b2a_base64 no longer places an arbitrary restriction of 57
50 bytes on its input.
51
Tim Peters84362bc2001-10-19 17:55:30 +000052Library
53
Martin v. Löwis25ee87c2001-11-07 22:38:08 +000054- tkFileDialog exposes a Directory class and askdirectory
55 convenience function.
56
Tim Peters75335872001-11-03 19:35:43 +000057- Symbolic group names in regular expressions must be unique. For
58 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
59 single name can't mean both "group 1" and "group 2" simultaneously.
60 Python 2.2 detects this error at regexp compilation time; previously,
61 the error went undetected, and results were unpredictable.
62
Martin v. Löwisb7b32602001-11-02 23:48:20 +000063- Tix exposes more commands through the classes DirSelectBox,
64 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
65 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
66 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
67
Tim Peters98791af2001-10-23 01:59:54 +000068- Traceback objects are now scanned by cyclic garbage collection, so
69 cycles created by casual use of sys.exc_info() no longer cause
70 permanent memory leaks (provided garbage collection is enabled).
71
Guido van Rossum49192142001-10-24 20:51:44 +000072- os.extsep -- a new variable needed by the RISCOS support. It is the
73 separator used by extensions, and is '.' on all platforms except
74 RISCOS, where it is '/'. There is no need to use this variable
75 unless you have a masochistic desire to port your code to RISCOS.
76
Tim Peters84362bc2001-10-19 17:55:30 +000077Tools/Demos
78
79Build
80
81C API
82
Tim Peters1fc240e2001-10-26 05:06:50 +000083- New function PySequence_Fast_GET_SIZE() returns the size of a non-
84 NULL result from PySequence_Fast(), more quickly than calling
85 PySequence_Size().
86
Tim Peters84362bc2001-10-19 17:55:30 +000087New platforms
88
Guido van Rossum86443212001-10-27 22:28:54 +000089- We've finally confirmed that this release builds on HP-UX 11.00,
90 *with* threads, and passes the test suite.
91
Tim Peters7a33d8b2001-11-05 02:51:07 +000092- Thanks to a series of patches from Michael Muller, Python may build
93 again under OS/2 Visual Age C++.
94
Guido van Rossum49192142001-10-24 20:51:44 +000095- Updated RISCOS port by Dietmar Schwertberger.
96
Tim Peters84362bc2001-10-19 17:55:30 +000097Tests
98
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000099- Added a test script for the curses module. It isn't run automatically;
100 regrtest.py must be run with '-u curses' to enable it.
101
Tim Peters84362bc2001-10-19 17:55:30 +0000102Windows
103
104
Tim Petersabf925f2001-09-28 21:53:42 +0000105What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000106Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000107===========================
108
109Type/class unification and new-style classes
110
Guido van Rossum687ae002001-10-15 22:03:32 +0000111- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000112 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000113 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000114 remains: the __dict__ of a new-style class is a read-only proxy; you
115 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000116 __defined__ attribute of new-style types no longer exists, for lack
117 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000118 future a __cache__ may be resurrected with a similar function, if I
119 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000120
Tim Peters1c9ca872001-10-04 06:43:12 +0000121- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
122 always returned None, even when there was a class docstring).
123
124- doctest now finds and runs docstrings attached to new-style classes,
125 class methods, static methods, and properties.
126
Guido van Rossum9074ef62001-10-16 21:34:49 +0000127Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000128
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000129- A very subtle syntactical pitfall in list comprehensions was fixed.
130 For example: [a+b for a in 'abc', for b in 'def']. The comma in
131 this example is a mistake. Previously, this would silently let 'a'
132 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
133 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
134 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
135 Note that [a for a in <singleton>] is a convoluted way to say
136 [<singleton>] anyway, so it's not like any expressiveness is lost.
137
Guido van Rossum9074ef62001-10-16 21:34:49 +0000138- getattr(obj, name, default) now only catches AttributeError, as
139 documented, rather than returning the default value for all
140 exceptions (which could mask bugs in a __getattr__ hook, for
141 example).
142
Fred Drakecb7a6b52001-10-22 18:41:51 +0000143- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000144 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000145 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000146 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000147
Guido van Rossum1c486092001-10-19 02:05:35 +0000148- unicode(obj) now behaves more like str(obj), accepting arbitrary
149 objects, and calling a __unicode__ method if it exists.
150 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000151 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000152
Barry Warsawf6fb1712001-10-19 05:35:40 +0000153- isinstance() now allows any object as the first argument and a
154 class, a type or something with a __bases__ tuple attribute for the
155 second argument. The second argument may also be a tuple of a
156 class, type, or something with __bases__, in which case isinstance()
157 will return true if the first argument is an instance of any of the
158 things contained in the second argument tuple. E.g.
159
160 isinstance(x, (A, B))
161
162 returns true if x is an instance of A or B.
163
Guido van Rossum9074ef62001-10-16 21:34:49 +0000164Extension modules
165
166- thread.start_new_thread() now returns the thread ID (previously None).
167
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000168- binascii has now two quopri support functions, a2b_qp and b2a_qp.
169
Guido van Rossumc524d952001-10-19 01:31:59 +0000170- readline now supports setting the startup_hook and the
171 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000172
Guido van Rossumc524d952001-10-19 01:31:59 +0000173- os and posix supports chroot(), setgroups() and unsetenv() where
174 available. The stat(), fstat(), statvfs() and fstatvfs() functions
175 now return "pseudo-sequences" -- the various fields can now be
176 accessed as attributes (e.g. os.stat("/").st_mtime) but for
177 backwards compatibility they also behave as a fixed-length sequence.
178 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000179 attributes.
180
181- time: localtime(), gmtime() and strptime() now return a
182 pseudo-sequence similar to the os.stat() return value, with
183 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000184
Guido van Rossum9074ef62001-10-16 21:34:49 +0000185- Decompression objects in the zlib module now accept an optional
186 second parameter to decompress() that specifies the maximum amount
187 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000188
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000189- optional SSL support in the socket module now exports OpenSSL
190 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
191 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000192 automatically seed its PRNG. Also, the keyfile and certfile
193 arguments to socket.ssl() are now optional.
194
195- posixmodule (and by extension, the os module on POSIX platforms) now
196 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000197
Guido van Rossum9074ef62001-10-16 21:34:49 +0000198Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000199
Tim Peters7402f792001-10-02 03:53:41 +0000200- doctest now excludes functions and classes not defined by the module
201 being tested, thanks to Tim Hochberg.
202
Fred Drakecb7a6b52001-10-22 18:41:51 +0000203- HotShot, a new profiler implemented using a C-based callback, has
204 been added. This substantially reduces the overhead of profiling,
205 but it is still quite preliminary. Support modules and
206 documentation will be added in upcoming releases (before 2.2 final).
207
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000208- profile now produces correct output in situations where an exception
209 raised in Python is cleared by C code (e.g. hasattr()). This used
210 to cause wrong output, including spurious claims of recursive
211 functions and attribution of time spent to the wrong function.
212
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000213 The code and documentation for the derived OldProfile and HotProfile
214 profiling classes was removed. The code hasn't worked for years (if
215 you tried to use them, they raised exceptions). OldProfile
216 intended to reproduce the behavior of the profiler Python used more
217 than 7 years ago, and isn't interesting anymore. HotProfile intended
218 to provide a faster profiler (but producing less information), and
219 that's a worthy goal we intend to meet via a different approach (but
220 without losing information).
221
Tim Peterscce092d2001-10-09 05:31:56 +0000222- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000223 a much better system-specific calibration constant. The constant can
224 now be specified in an instance constructor, or as a Profile class or
225 instance variable, instead of by editing profile.py's source code.
226 Calibration must still be done manually (see the docs for the profile
227 module).
228
229 Note that Profile.calibrate() must be overriden by subclasses.
230 Improving the accuracy required exploiting detailed knowledge of
231 profiler internals; the earlier method abstracted away the details
232 and measured a simplified model instead, but consequently computed
233 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000234
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000235- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000236 which indicates whether output is intended for the header 'Q'
237 encoding.
238
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000239- The SocketServer.ThreadingMixIn class now closes the request after
240 finish_request() returns. (Not when it errors out though.)
241
Barry Warsawf6fb1712001-10-19 05:35:40 +0000242- The nntplib module's NNTP.body() method has grown a `file' argument
243 to allow saving the message body to a file.
244
245- The email package has added a class email.Parser.HeaderParser which
246 only parses headers and does not recurse into the message's body.
247 Also, the module/class MIMEAudio has been added for representing
248 audio data (contributed by Anthony Baxter).
249
250- ftplib should be able to handle files > 2GB.
251
252- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
253 ON, and OFF.
254
Fred Drakecb7a6b52001-10-22 18:41:51 +0000255- xml.dom.minidom NodeList objects now support the length attribute
256 and item() method as required by the DOM specifications.
257
Guido van Rossumed554f62001-10-02 23:15:37 +0000258Tools/Demos
259
260- Demo/dns was removed. It no longer serves any purpose; a package
261 derived from it is now maintained by Anthony Baxter, see
262 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000263
Barry Warsawf6fb1712001-10-19 05:35:40 +0000264- The freeze tool has been made more robust, and two new options have
265 been added: -X and -E.
266
Tim Petersabf925f2001-09-28 21:53:42 +0000267Build
268
Barry Warsawf6fb1712001-10-19 05:35:40 +0000269- configure will use CXX in LINKCC if CXX is used to build main() and
270 the system requires to link a C++ main using the C++ compiler.
271
Tim Petersabf925f2001-09-28 21:53:42 +0000272C API
273
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000274- The documentation for the tp_compare slot is updated to require that
275 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
276 not correct. This is not yet enforced but will be enforced in
277 Python 2.3; even later, we may use -2 to indicate errors and +2 for
278 "NotImplemented". Right now, -1 should be used for an error return.
279
Tim Petersd38b1c72001-09-30 05:09:37 +0000280- PyLong_AsLongLong() now accepts int (as well as long) arguments.
281 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
282 as long) arguments.
283
Guido van Rossum3c288632001-10-16 21:13:49 +0000284- PyThread_start_new_thread() now returns a long int giving the thread
285 ID, if one can be calculated; it returns -1 for error, 0 if no
286 thread ID is calculated (this is an incompatible change, but only
287 the thread module used this API). This code has only really been
288 tested on Linux and Windows; other platforms please beware (and
289 report any bugs or strange behavior).
290
Guido van Rossum1c486092001-10-19 02:05:35 +0000291- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
292 input.
293
Tim Petersabf925f2001-09-28 21:53:42 +0000294New platforms
295
296Tests
297
298Windows
299
Tim Peters04cf1d32001-10-09 22:39:40 +0000300- Installer: If you install IDLE, and don't disable file-extension
301 registration, a new "Edit with IDLE" context (right-click) menu entry
302 is created for .py and .pyw files.
303
Tim Peters1ce3cf72001-10-01 17:58:40 +0000304- The signal module now supports SIGBREAK on Windows, thanks to Steven
305 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
306 action remains to call Win32 ExitProcess(). This can be changed via
307 signal.signal(). For example:
308
309 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
310 # (SIGINT) behavior.
311 import signal
312 signal.signal(signal.SIGBREAK,
313 signal.default_int_handler)
314
315 try:
316 while 1:
317 pass
318 except KeyboardInterrupt:
319 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
320 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
321 # program without the possibility for any Python-level cleanup).
322 print "Clean exit"
323
Tim Petersabf925f2001-09-28 21:53:42 +0000324
Tim Petersb07352e2001-09-08 01:25:47 +0000325What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000326Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000327===========================
328
Guido van Rossum808eea72001-09-25 04:15:41 +0000329Type/class unification and new-style classes
330
331- pydoc and inspect are now aware of new-style classes;
332 e.g. help(list) at the interactive prompt now shows proper
333 documentation for all operations on list objects.
334
335- Applications using Jim Fulton's ExtensionClass module can now safely
336 be used with Python 2.2. In particular, Zope 2.4.1 now works with
337 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
338 examples also work again. It is hoped that Gtk and Boost also work
339 with 2.2a4 and beyond. (If you can confirm this, please write
340 webmaster@python.org; if there are still problems, please open a bug
341 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000342
Tim Peters66c1a522001-09-24 21:17:50 +0000343- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
344 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
345 in the constructed property object. fget, fset and fdel weren't
346 discoverable from Python in 2.2a3. __doc__ is new, and allows to
347 associate a docstring with a property.
348
Guido van Rossum808eea72001-09-25 04:15:41 +0000349- Comparison overloading is now more completely implemented. For
350 example, a str subclass instance can properly be compared to a str
351 instance, and it can properly overload comparison. Ditto for most
352 other built-in object types.
353
354- The repr() of new-style classes has changed; instead of <type
355 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
356 *except* for built-in types, which are still rendered as <type
357 'Foo'> (to avoid upsetting existing code that might parse or
358 otherwise rely on repr() of certain type objects).
359
360- The repr() of new-style objects is now always <Foo object at XXX>;
361 previously, it was sometimes <Foo instance at XXX>.
362
363- For new-style classes, what was previously called __getattr__ is now
364 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000365 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000366 one in classic classes is defined which is called only if regular
367 attribute access raises AttributeError; to catch *all* attribute
368 access, you can use __getattribute__ (for new-style classes). If
369 both are defined, __getattribute__ is called first, and if it raises
370 AttributeError, __getattr__ is called.
371
372- The __class__ attribute of new-style objects can be assigned to.
373 The new class must have the same C-level object layout as the old
374 class.
375
376- The builtin file type can be subclassed now. In the usual pattern,
377 "file" is the name of the builtin type, and file() is a new builtin
378 constructor, with the same signature as the builtin open() function.
379 file() is now the preferred way to open a file.
380
381- Previously, __new__ would only see sequential arguments passed to
382 the type in a constructor call; __init__ would see both sequential
383 and keyword arguments. This made no sense whatsoever any more, so
384 now both __new__ and __init__ see all arguments.
385
386- Previously, hash() applied to an instance of a subclass of str or
387 unicode always returned 0. This has been repaired.
388
389- Previously, an operation on an instance of a subclass of an
390 immutable type (int, long, float, complex, tuple, str, unicode),
391 where the subtype didn't override the operation (and so the
392 operation was handled by the builtin type), could return that
393 instance instead a value of the base type. For example, if s was of
394 a str sublass type, s[:] returned s as-is. Now it returns a str
395 with the same value as s.
396
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000397- Provisional support for pickling new-style objects has been added.
398
Guido van Rossum808eea72001-09-25 04:15:41 +0000399Core
400
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000401- file.writelines() now accepts any iterable object producing strings.
402
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000403- PyUnicode_FromEncodedObject() now works very much like
404 PyObject_Str(obj) in that it tries to use __str__/tp_str
405 on the object if the object is not a string or buffer. This
406 makes unicode() behave like str() when applied to non-string/buffer
407 objects.
408
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000409- PyFile_WriteObject now passes Unicode objects to the file's write
410 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000411 of a print statement must support Unicode objects, i.e. they must
412 at least convert them into ASCII strings.
413
Guido van Rossum624c8af2001-09-18 15:21:04 +0000414- Thread scheduling on Solaris should be improved; it is no longer
415 necessary to insert a small sleep at the start of a thread in order
416 to let other runnable threads be scheduled.
417
Tim Petersb07352e2001-09-08 01:25:47 +0000418Library
419
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000420- StringIO.StringIO instances and cStringIO.StringIO instances support
421 read character buffer compatible objects for their .write() methods.
422 These objects are converted to strings and then handled as such
423 by the instances.
424
Barry Warsaw2f600732001-09-24 04:28:10 +0000425- The "email" package has been added. This is basically a port of the
426 mimelib package <http://sf.net/projects/mimelib> with API changes
427 and some implementations updated to use iterators and generators.
428
Tim Peters8a9c2842001-09-22 21:30:22 +0000429- difflib.ndiff() and difflib.Differ.compare() are generators now. This
430 restores the ability of Tools/scripts/ndiff.py to start producing output
431 before the entire comparison is complete.
432
Barry Warsaw58b072d2001-09-22 04:44:21 +0000433- StringIO.StringIO instances and cStringIO.StringIO instances support
434 iteration just like file objects (i.e. their .readline() method is
435 called for each iteration until it returns an empty string).
436
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000437- The codecs module has grown four new helper APIs to access
438 builtin codecs: getencoder(), getdecoder(), getreader(),
439 getwriter().
440
Guido van Rossum624c8af2001-09-18 15:21:04 +0000441- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
442 simplifies writing XML RPC servers.
443
Barry Warsaw647d5e82001-09-28 17:01:02 +0000444- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000445 after interpretation of symbolic links. On non-Unix systems, this
446 is an alias for os.path.abspath().
447
Tim Peters16a77ad2001-09-08 04:00:12 +0000448- operator.indexOf() (PySequence_Index() in the C API) now works with any
449 iterable object.
450
Guido van Rossum624c8af2001-09-18 15:21:04 +0000451- smtplib now supports various authentication and security features of
452 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000453
Guido van Rossum624c8af2001-09-18 15:21:04 +0000454- hmac: a new module implementing keyed hashing for message
455 authentication.
456
457- mimetypes now recognizes more extensions and file types. At the
458 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000459
Guido van Rossum624c8af2001-09-18 15:21:04 +0000460- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000461 Python 2.2 bytecode generation. It has also been promoted from a
462 Tool to a standard library package. (Tools/compiler still exists as
463 a sample driver.)
464
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000465Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000466
Tim Petersb07352e2001-09-08 01:25:47 +0000467Build
468
Guido van Rossum624c8af2001-09-18 15:21:04 +0000469- Large file support (LFS) is now automatic when the platform supports
470 it; no more manual configuration tweaks are needed. On Linux, at
471 least, it's possible to have a system whose C library supports large
472 files but whose kernel doesn't; in this case, large file support is
473 still enabled but doesn't do you any good unless you upgrade your
474 kernel or share your Python executable with another system whose
475 kernel has large file support.
476
477- The configure script now supplies plausible defaults in a
478 cross-compilation environment. This doesn't mean that the supplied
479 values are always correct, or that cross-compilation now works
480 flawlessly -- but it's a first step (and it shuts up most of
481 autoconf's warnings about AC_TRY_RUN).
482
483- The Unix build is now a bit less chatty, courtesy of the parser
484 generator. The build is completely silent (except for errors) when
485 using "make -s", thanks to a -q option to setup.py.
486
Tim Petersb07352e2001-09-08 01:25:47 +0000487C API
488
Guido van Rossum624c8af2001-09-18 15:21:04 +0000489- The "structmember" API now supports some new flag bits to deny read
490 and/or write access to attributes in restricted execution mode.
491
Tim Petersb07352e2001-09-08 01:25:47 +0000492New platforms
493
Guido van Rossum624c8af2001-09-18 15:21:04 +0000494- Compaq's iPAQ handheld, running the "familiar" Linux distribution
495 (http://familiar.handhelds.org).
496
Tim Petersb07352e2001-09-08 01:25:47 +0000497Tests
498
Tim Peters8a9c2842001-09-22 21:30:22 +0000499- The "classic" standard tests, which work by comparing stdout to
500 an expected-output file under Lib/test/output/, no longer stop at
501 the first mismatch. Instead the test is run to completion, and a
502 variant of ndiff-style comparison is used to report all differences.
503 This is much easier to understand than the previous style of reporting.
504
505- The unittest-based standard tests now use regrtest's test_main()
506 convention, instead of running as a side-effect of merely being
507 imported. This allows these tests to be run in more natural and
508 flexible ways as unittests, outside the regrtest framework.
509
510- regrtest.py is much better integrated with unittest and doctest now,
511 especially in regard to reporting errors.
512
Tim Petersb07352e2001-09-08 01:25:47 +0000513Windows
514
Guido van Rossum624c8af2001-09-18 15:21:04 +0000515- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000516 that support it (NTFS under Windows 2000). See "What's New in
517 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000518
Tim Petersb07352e2001-09-08 01:25:47 +0000519
Tim Petersedc99312001-08-22 21:36:50 +0000520What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000521Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000522===========================
523
524Core
525
Tim Peters9fffa3e2001-09-04 05:14:19 +0000526- Conversion of long to float now raises OverflowError if the long is too
527 big to represent as a C double.
528
Tim Peters32f453e2001-09-03 08:35:41 +0000529- The 3-argument builtin pow() no longer allows a third non-None argument
530 if either of the first two arguments is a float, or if both are of
531 integer types and the second argument is negative (in which latter case
532 the arguments are converted to float, so this is really the same
533 restriction).
534
Tim Peters5d2b77c2001-09-03 05:47:38 +0000535- The builtin dir() now returns more information, and sometimes much
536 more, generally naming all attributes of an object, and all attributes
537 reachable from the object via its class, and from its class's base
538 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
539 an empty list. In 2.2a3,
540
541 >>> dir([])
542 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
543 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
544 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
545 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
546 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
547 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
548 'reverse', 'sort']
549
550 dir(module) continues to return only the module's attributes, though.
551
Tim Petersbdee63f2001-09-02 03:40:59 +0000552- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000553 than raising OverflowError. This is a partial implementation of PEP
554 237. You can use -Wdefault::OverflowWarning to enable a warning for
555 this situation, and -Werror::OverflowWarning to revert to the old
556 OverflowError exception.
557
Guido van Rossum61c345f2001-09-04 03:26:15 +0000558- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000559 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000560 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
561 -Qold, meaning the / operator has its classic meaning and no
562 warnings are issued. Using -Qwarn issues a run-time warning about
563 all uses of classic division for int and long arguments; -Qwarnall
564 also warns about classic division for float and complex arguments
565 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
566 new division by default, but only in the __main__ module. You can
567 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
568 __main__ module new division, and warns about classic division
569 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000570
Tim Petersbdee63f2001-09-02 03:40:59 +0000571- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000572 long, float, str, unicode, and tuple. (The types complex, list and
573 dictionary can also be subclassed; this was introduced earlier.)
574 Note that restrictions apply when subclassing immutable built-in
575 types: you can only affect the value of the instance by overloading
576 __new__. You can add mutable attributes, and the subclass instances
577 will have a __dict__ attribute, but you cannot change the "value"
578 (as implemented by the base class) of an immutable subclass instance
579 once it is created.
580
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000581- The dictionary constructor now takes an optional argument, a
582 mapping-like object, and initializes the dictionary from its
583 (key, value) pairs.
584
Tim Petersbdee63f2001-09-02 03:40:59 +0000585- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000586 "cooperative super calls" in a multiple inheritance setting. For an
587 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
588
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000589- A new built-in type, property, has been added. This enables the
590 creation of "properties". These are attributes implemented by
591 getter and setter functions (or only one of these for read-only or
592 write-only attributes), without the need to override __getattr__.
593 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000594
Tim Petersbdee63f2001-09-02 03:40:59 +0000595- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000596 liberalized, to allow leading zeroes. Examples of literals now
597 legal that were SyntaxErrors before:
598
599 00.0 0e3 0100j 07.5 00000000000000000008.
600
Tim Petersbdee63f2001-09-02 03:40:59 +0000601- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000602 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
603
Tim Petersedc99312001-08-22 21:36:50 +0000604Library
605
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000606- telnetlib includes symbolic names for the options, and support for
607 setting an option negotiation callback.
608
Tim Petersa40c7932001-09-05 22:36:56 +0000609- The new C standard no longer requires that math libraries set errno to
610 ERANGE on overflow. For platform libraries that exploit this new
611 freedom, Python's overflow-checking was wholly broken. A new overflow-
612 checking scheme attempts to repair that, but may not be reliable on all
613 platforms (C doesn't seem to provide anything both useful and portable
614 in this area anymore).
615
Martin v. Löwis44f86962001-09-05 13:44:54 +0000616- Asynchronous timeout actions are available through the new class
617 threading.Timer.
618
Tim Peters78526162001-09-05 00:53:45 +0000619- math.log and math.log10 now return sensible results for even huge
620 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
621
Tim Petersbdee63f2001-09-02 03:40:59 +0000622- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000623 currently held. See the docs for the imp module.
624
Tim Petersbdee63f2001-09-02 03:40:59 +0000625- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000626 dumps containing ints written on platforms where Python ints are 8 bytes.
627 When read on a box where Python ints are 4 bytes, such values are
628 converted to Python longs.
629
Tim Petersbdee63f2001-09-02 03:40:59 +0000630- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000631 code objects is no longer allowed. This plugs a security hole.
632
Steve Purcell6091cd62001-09-06 16:05:17 +0000633- unittest.TestResult instances no longer store references to tracebacks
634 generated by test failures. This prevents unexpected dangling references
635 to objects that should be garbage collected between tests.
636
Tim Petersedc99312001-08-22 21:36:50 +0000637Tools
638
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000639- Tools/scripts/fixdiv.py has been added which can be used to fix
640 division operators as per PEP 238.
641
Tim Petersedc99312001-08-22 21:36:50 +0000642Build
643
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000644- If you are an adventurous person using Mac OS X you may want to look at
645 Mac/OSX. There is a Makefile there that will build Python as a real Mac
646 application, which can be used for experimenting with Carbon or Cocoa.
647 Discussion of this on pythonmac-sig, please.
648
Tim Peters7eea37e2001-09-04 22:08:56 +0000649C API
650
651- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000652
Tim Peters9fffa3e2001-09-04 05:14:19 +0000653- Note that PyLong_AsDouble can fail! This has always been true, but no
654 callers checked for it. It's more likely to fail now, because overflow
655 errors are properly detected now. The proper way to check:
656
657 double x = PyLong_AsDouble(some_long_object);
658 if (x == -1.0 && PyErr_Occurred()) {
659 /* The conversion failed. */
660 }
661
Tim Petersbdee63f2001-09-02 03:40:59 +0000662- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000663 compile but will not participate in GC. To upgrade an extension
664 module:
665
666 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000667
Neil Schemenauer4042c692001-08-30 15:38:01 +0000668 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
669 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000670
Neil Schemenauer4042c692001-08-30 15:38:01 +0000671 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
672 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000673
Neil Schemenauer4042c692001-08-30 15:38:01 +0000674 - remove PyGC_HEAD_SIZE from object size calculations
675
676 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
677
Tim Petersbdee63f2001-09-02 03:40:59 +0000678- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000679 These can be used safely to construct string objects from a
680 sprintf-style format string (similar to the format string supported
681 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000682
Tim Petersedc99312001-08-22 21:36:50 +0000683New platforms
684
Tim Petersb7da0902001-09-02 23:01:43 +0000685- Stephen Hansen contributed patches sufficient to get a clean compile
686 under Borland C (Windows), but he reports problems running it and ran
687 out of time to complete the port. Volunteers? Expect a MemoryError
688 when importing the types module; this is probably shallow, and
689 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000690
Tim Petersedc99312001-08-22 21:36:50 +0000691Tests
692
693Windows
694
Tim Peters6e13a562001-09-06 00:32:15 +0000695- Large file support is now enabled on Win32 platforms as well as on
696 Win64. This means that, for example, you can use f.tell() and f.seek()
697 to manipulate files larger than 2 gigabytes (provided you have enough
698 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000699 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
700 filesize limit, and large file support makes no difference there.
701 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
702 NTFS has no practical limit on file size, and files of any size can be
703 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000704
Tim Petersbdee63f2001-09-02 03:40:59 +0000705- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000706 points to command.com (patch from Brian Quinlan).
707
Tim Petersedc99312001-08-22 21:36:50 +0000708
Tim Peters20f51a72001-07-21 02:31:40 +0000709What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000710Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000711===========================
712
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000713Build
714
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000715- Tim Peters developed a brand new Windows installer using Wise 8.1,
716 generously donated to us by Wise Solutions.
717
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000718- configure supports a new option --enable-unicode, with the values
719 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
720 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000721
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000722- A new configure option --enable-framework builds a Mac OS X framework,
723 which "make frameworkinstall" will install. This provides a starting
724 point for more mac-like functionality, join pythonmac-sig@python.org
725 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000726
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000727- The NeXT platform is no longer supported.
728
729- The `new' module is now statically linked.
730
Tim Peters0afb6092001-08-15 06:06:44 +0000731Tools
732
733- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000734 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000735 the module docstring for details.
736
Tim Peters20f51a72001-07-21 02:31:40 +0000737Tests
738
Tim Peters5e824c32001-08-12 22:25:01 +0000739- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000740 platforms, allowing to give clearer test result output. regrtest
741 also has optional --use/-u switch to run normally disabled tests
742 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000743
Tim Peters20f51a72001-07-21 02:31:40 +0000744- Several new tests in the standard test suite, with special thanks to
745 Nick Mathewson.
746
747Core
748
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000749- The floor division operator // has been added as outlined in PEP
750 238. The / operator still provides classic division (and will until
751 Python 3.0) unless "from __future__ import division" is included, in
752 which case the / operator will provide true division. The operator
753 module provides truediv() and floordiv() functions. Augmented
754 assignment variants are included, as are the equivalent overloadable
755 methods and C API methods. See the PEP for a full discussion:
756 <http://python.sf.net/peps/pep-0238.html>
757
Tim Peters6cd6a822001-08-17 22:11:27 +0000758- Future statements are now effective in simulated interactive shells
759 (like IDLE). This should "just work" by magic, but read Michael
760 Hudson's "Future statements in simulated shells" PEP 264 for full
761 details: <http://python.sf.net/peps/pep-0264.html>.
762
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000763- The type/class unification (PEP 252-253) was integrated into the
764 trunk and is not so tentative any more (the exact specification of
765 some features is still tentative). A lot of work has done on fixing
766 bugs and adding robustness and features (performance still has to
767 come a long way).
768
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000769- Warnings about a mismatch in the Python API during extension import
770 now use the Python warning framework (which makes it possible to
771 write filters for these warnings).
772
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000773- A function's __dict__ (aka func_dict) will now always be a
774 dictionary. It used to be possible to delete it or set it to None,
775 but now both actions raise TypeErrors. It is still legal to set it
776 to a dictionary object. Getting func.__dict__ before any attributes
777 have been assigned now returns an empty dictionary instead of None.
778
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000779- A new command line option, -E, was added which disables the use of
780 all environment variables, or at least those that are specifically
781 significant to Python. Usually those have a name starting with
782 "PYTHON". This was used to fix a problem where the tests fail if
783 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
784 older distribution.
785
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000786Library
787
Tim Peters5e824c32001-08-12 22:25:01 +0000788- New class Differ and new functions ndiff() and restore() in difflib.py.
789 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000790 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000791
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000792- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
793 value using the minimal quoting required for the value; more
794 reliable than using xml.sax.saxutils.escape() for attribute values.
795
796- Readline completion support for cmd.Cmd was added.
797
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000798- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
799
800- Added function threading.BoundedSemaphore()
801
802- Added Ka-Ping Yee's cgitb.py module.
803
804- The `new' module now exposes the CO_xxx flags.
805
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000806New platforms
807
808C API
809
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000810- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
811 which provide a cross-platform implementations for the
812 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
813 the standard sprintf() and vsprintf() C lib APIs, these versions
814 apply bounds checking on the used buffer which enhances protection
815 against buffer overruns.
816
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000817- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000818 and extensions using different Unicode widths is rendered next to
819 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000820 will result in an ImportError. Unicode extensions writers must make
821 sure to check the Unicode width compatibility in their extensions by
822 using at least one of the mangled Unicode APIs in the extension.
823
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000824- Two new flags METH_NOARGS and METH_O are available in method definition
825 tables to simplify implementation of methods with no arguments and a
826 single untyped argument. Calling such methods is more efficient than
827 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
828 deprecated.
829
Tim Petersc1731372001-08-04 08:12:36 +0000830Windows
831
832- "import module" now compiles module.pyw if it exists and nothing else
833 relevant is found.
834
Tim Peters20f51a72001-07-21 02:31:40 +0000835
Guido van Rossum55a78992001-07-17 17:22:32 +0000836What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +0000837Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +0000838===========================
839
840Core
Tim Petersa814db52001-05-14 07:05:58 +0000841
Tim Peters6d6c1a32001-08-02 04:15:00 +0000842- TENTATIVELY, a large amount of code implementing much of what's
843 described in PEP 252 (Making Types Look More Like Classes) and PEP
844 253 (Subtyping Built-in Types) was added. This will be released
845 with Python 2.2a1. Documentation will be provided separately
846 through http://www.python.org/2.2/. The purpose of releasing this
847 with Python 2.2a1 is to test backwards compatibility. It is
848 possible, though not likely, that a decision is made not to release
849 this code as part of 2.2 final, if any serious backwards
850 incompapatibilities are found during alpha testing that cannot be
851 repaired.
852
Guido van Rossum55a78992001-07-17 17:22:32 +0000853- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000854 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000855 more 'yield' statements. See PEP 255. Since this adds a new
856 keyword to the language, this feature must be enabled by including a
857 future statement: "from __future__ import generators" (see PEP 236).
858 Generators will become a standard feature in a future release
859 (probably 2.3). Without this future statement, 'yield' remains an
860 ordinary identifier, but a warning is issued each time it is used.
861 (These warnings currently don't conform to the warnings framework of
862 PEP 230; we intend to fix this in 2.2a2.)
863
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000864- The UTF-16 codec was modified to be more RFC compliant. It will now
865 only remove BOM characters at the start of the string and then
866 only if running in native mode (UTF-16-LE and -BE won't remove a
867 leading BMO character).
868
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000869- Strings now have a new method .decode() to complement the already
870 existing .encode() method. These two methods provide direct access
871 to the corresponding decoders and encoders of the registered codecs.
872
873 To enhance the usability of the .encode() method, the special
874 casing of Unicode object return values was dropped (Unicode objects
875 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000876
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000877 Both methods will now return whatever the codec in charge of the
878 requested encoding returns as object, e.g. Unicode codecs will
879 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
880 will return u"äöü"). This enables codec writer to create codecs
881 for various simple to use conversions.
882
883 New codecs were added to demonstrate these new features (the .encode()
884 and .decode() columns indicate the type of the returned objects):
885
886 Name | .encode() | .decode() | Description
887 ----------------------------------------------------------------------
888 uu | string | string | UU codec (e.g. for email)
889 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000890 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000891 zlib | string | string | zlib compression
892 hex | string | string | 2-byte hex codec
893 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
894
Mark Hammond2a0af792001-05-14 03:09:36 +0000895- Some operating systems now support the concept of a default Unicode
896 encoding for file system operations. Notably, Windows supports 'mbcs'
897 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000898 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000899 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000900
901 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000902 functions that return filenames (such as os.listdir()) to return Python
903 string objects pre-encoded using the default file system encoding for
904 the platform. As this encoding is likely to be different from Python's
905 default encoding, converting this name to a Unicode object before passing
906 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000907 would attempt to use its default encoding (generally ASCII) rather than
908 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000909
Tim Petersa814db52001-05-14 07:05:58 +0000910 In general, this change simply removes surprises when working with
911 Unicode and the file system, making these operations work as you expect,
912 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000913 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000914
Tim Peters61dff2b2001-05-08 15:43:37 +0000915- Float (and complex) literals in source code were evaluated to full
916 precision only when running from a .py file; the same code loaded from a
917 .pyc (or .pyo) file could suffer numeric differences starting at about the
918 12th significant decimal digit. For example, on a machine with IEEE-754
919 floating arithmetic,
920
921 x = 9007199254740992.0
922 print long(x)
923
924 printed 9007199254740992 if run directly from .py, but 9007199254740000
925 if from a compiled (.pyc or .pyo) file. This was due to marshal using
926 str(float) instead of repr(float) when building code objects. marshal
927 now uses repr(float) instead, which should reproduce floats to full
928 machine precision (assuming the platform C float<->string I/O conversion
929 functions are of good quality).
930
931 This may cause floating-point results to change in some cases, and
932 usually for the better, but may also cause numerically unstable
933 algorithms to break.
934
Tim Peters2f228e72001-05-13 00:19:31 +0000935- The implementation of dicts suffers fewer collisions, which has speed
936 benefits. However, the order in which dict entries appear in dict.keys(),
937 dict.values() and dict.items() may differ from previous releases for a
938 given dict. Nothing is defined about this order, so no program should
939 rely on it. Nevertheless, it's easy to write test cases that rely on the
940 order by accident, typically because of printing the str() or repr() of a
941 dict to an "expected results" file. See Lib/test/test_support.py's new
942 sortdict(dict) function for a simple way to display a dict in sorted
943 order.
944
Tim Peters7a3bfc32001-06-12 01:22:22 +0000945- Many other small changes to dicts were made, resulting in faster
946 operation along the most common code paths.
947
Guido van Rossum10315822001-05-01 20:54:30 +0000948- Dictionary objects now support the "in" operator: "x in dict" means
949 the same as dict.has_key(x).
950
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000951- The update() method of dictionaries now accepts generic mapping
952 objects. Specifically the argument object must support the .keys()
953 and __getitem__() methods. This allows you to say, for example,
954 {}.update(UserDict())
955
Guido van Rossum10315822001-05-01 20:54:30 +0000956- Iterators were added; this is a generalized way of providing values
957 to a for loop. See PEP 234. There's a new built-in function iter()
958 to return an iterator. There's a new protocol to get the next value
959 from an iterator using the next() method (in Python) or the
960 tp_iternext slot (in C). There's a new protocol to get iterators
961 using the __iter__() method (in Python) or the tp_iter slot (in C).
962 Iterating (i.e. a for loop) over a dictionary generates its keys.
963 Iterating over a file generates its lines.
964
Tim Petersf553f892001-05-01 20:45:31 +0000965- The following functions were generalized to work nicely with iterator
966 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000967 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000968 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
969 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000970 join() method of strings
971 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000972 'x in y' and 'x not in y' (PySequence_Contains() in C API)
973 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000974 right-hand side of assignment statements with multiple targets, such as
975 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000976
Tim Petersd85e1022001-05-11 21:51:48 +0000977- Accessing module attributes is significantly faster (for example,
978 random.random or os.path or yourPythonModule.yourAttribute).
979
Tim Peterse63415e2001-05-08 04:38:29 +0000980- Comparing dictionary objects via == and != is faster, and now works even
981 if the keys and values don't support comparisons other than ==.
982
Tim Peters95bf9392001-05-10 08:32:44 +0000983- Comparing dictionaries in ways other than == and != is slower: there were
984 insecurities in the dict comparison implementation that could cause Python
985 to crash if the element comparison routines for the dict keys and/or
986 values mutated the dicts. Making the code bulletproof slowed it down.
987
Tim Peterseb28ef22001-06-02 05:27:19 +0000988- Collisions in dicts are resolved via a new approach, which can help
989 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000990 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000991 faster now. Thanks to Christian Tismer for pointing out the cause and
992 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000993
Tim Peters52e155e2001-06-16 05:42:57 +0000994- repr() is much faster for large containers (dict, list, tuple).
995
996
Tim Petersa814db52001-05-14 07:05:58 +0000997Library
998
Fred Drake960fdf92001-07-20 18:38:26 +0000999- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1000 were added to the string module. These a locale-indenpendent
1001 constants, unlike letters, lowercase, and uppercase. These are now
1002 use in appropriate locations in the standard library.
1003
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001004- The flags used in dlopen calls can now be configured using
1005 sys.setdlopenflags and queried using sys.getdlopenflags.
1006
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001007- Fredrik Lundh's xmlrpclib is now a standard library module. This
1008 provides full client-side XML-RPC support. In addition,
1009 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1010 one asyncore-based). Thanks to Eric Raymond for the documentation.
1011
Guido van Rossum643d3912001-07-05 14:46:25 +00001012- The xrange() object is simplified: it no longer supports slicing,
1013 repetition, comparisons, efficient 'in' checking, the tolist()
1014 method, or the start, stop and step attributes. See PEP 260.
1015
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001016- A new function fnmatch.filter to filter lists of file names was added.
1017
Barry Warsawffd674d2001-05-22 16:00:10 +00001018- calendar.py uses month and day names based on the current locale.
1019
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001020- strop is now *really* obsolete (this was announced before with 1.6),
1021 and issues DeprecationWarning when used (except for the four items
1022 that are still imported into string.py).
1023
Tim Petersa814db52001-05-14 07:05:58 +00001024- Cookie.py now sorts key+value pairs by key in output strings.
1025
1026- pprint.isrecursive(object) didn't correctly identify recursive objects.
1027 Now it does.
1028
Tim Peters95b3f782001-05-14 18:39:41 +00001029- pprint functions now much faster for large containers (tuple, list, dict).
1030
Tim Peters7b9542a2001-06-10 23:40:19 +00001031- New 'q' and 'Q' format codes in the struct module, corresponding to C
1032 types "long long" and "unsigned long long" (on Windows, __int64). In
1033 native mode, these can be used only when the platform C compiler supports
1034 these types (when HAVE_LONG_LONG is #define'd by the Python config
1035 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001036 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1037 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001038
Guido van Rossum83213cc2001-06-12 16:48:52 +00001039- The site module installs a new built-in function 'help' that invokes
1040 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1041 it displays a message reminding the user to use 'help()' or
1042 'help(object)'.
1043
Tim Petersa814db52001-05-14 07:05:58 +00001044Tests
1045
1046- New test_mutants.py runs dict comparisons where the key and value
1047 comparison operators mutute the dicts randomly during comparison. This
1048 rapidly causes Python to crash under earlier releases (not for the faint
1049 of heart: it can also cause Win9x to freeze or reboot!).
1050
1051- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001052 pprint.isreadable() return sensible results. Also verifies that simple
1053 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001054
Tim Peters4324aa32001-05-28 22:30:08 +00001055C API
1056
1057- Removed the unused last_is_sticky argument from the internal
1058 _PyTuple_Resize(). If this affects you, you were cheating.
1059
1060
Guido van Rossum55a78992001-07-17 17:22:32 +00001061======================================================================
1062
1063
Guido van Rossumffe13be2001-04-16 18:46:45 +00001064What's New in Python 2.1 (final)?
1065=================================
1066
1067We only changed a few things since the last release candidate, all in
1068Python library code:
1069
1070- A bug in the locale module was fixed that affected locales which
1071 define no grouping for numeric formatting.
1072
1073- A few bugs in the weakref module's implementations of weak
1074 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1075 and the test suite was updated to check for these bugs.
1076
1077- An old bug in the os.path.walk() function (introduced in Python
1078 2.0!) was fixed: a non-existent file would cause an exception
1079 instead of being ignored.
1080
1081- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1082 PyChecker.
1083
1084
Guido van Rossum5b08f132001-04-16 02:05:23 +00001085What's New in Python 2.1c2?
1086===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001087
Guido van Rossum5b08f132001-04-16 02:05:23 +00001088A flurry of small changes, and one showstopper fixed in the nick of
1089time made it necessary to release another release candidate. The list
1090here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001091
Guido van Rossum5b08f132001-04-16 02:05:23 +00001092Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001093
Guido van Rossum5b08f132001-04-16 02:05:23 +00001094- Tim discovered a nasty bug in the dictionary code, caused by
1095 PyDict_Next() calling dict_resize(), and the GC code's use of
1096 PyDict_Next() violating an assumption in dict_items(). This was
1097 fixed with considerable amounts of band-aid, but the net effect is a
1098 saner and more robust implementation.
1099
1100- Made a bunch of symbols static that were accidentally global.
1101
1102Build and Ports
1103
1104- The setup.py script didn't check for a new enough version of zlib
1105 (1.1.3 is needed). Now it does.
1106
1107- Changed "make clean" target to also remove shared libraries.
1108
1109- Added a more general warning about the SGI Irix optimizer to README.
1110
1111Library
1112
1113- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1114 omitted the slash between host and file.html.
1115
1116- The mailbox module's _Mailbox class contained a completely broken
1117 and undocumented seek() method. Ripped it out.
1118
1119- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1120 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1121
1122- Fixed a few last-minute bugs in unittest.
1123
1124Extensions
1125
1126- Reverted the patch to the OpenSSL code in socketmodule.c to support
1127 RAND_status() and the EGD, and the subsequent patch that tried to
1128 fix it for pre-0.9.5 versions; the problem with the patch is that on
1129 some systems it issues a warning whenever socket is imported, and
1130 that's unacceptable.
1131
1132Tests
1133
1134- Fixed the pickle tests to work with "import test.test_pickle".
1135
1136- Tweaked test_locale.py to actually run the test Windows.
1137
1138- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1139 not "wb" (which is not a valid mode at all).
1140
1141- Fix pstats browser crashes. Import readline if it exists to make
1142 the user interface nicer.
1143
1144- Add "import thread" to the top of test modules that import the
1145 threading module (test_asynchat and test_threadedtempfile). This
1146 prevents test failures caused by a broken threading module resulting
1147 from a previously caught failed import.
1148
1149- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1150 needed on some platforms (e.g. Solaris 8) when the tests are run
1151 twice in succession.
1152
1153- Skip rather than fail test_sunaudiodev if no audio device is found.
1154
1155
1156What's New in Python 2.1c1?
1157===========================
1158
1159This list was significantly updated when 2.1c2 was released; the 2.1c1
1160release didn't mention most changes that were actually part of 2.1c1:
1161
1162Legal
1163
1164- Copyright was assigned to the Python Software Foundation (PSF) and a
1165 PSF license (very similar to the CNRI license) was added.
1166
1167- The CNRI copyright notice was updated to include 2001.
1168
1169Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001170
Guido van Rossumc9932722001-04-12 02:31:27 +00001171- After a public outcry, assignment to __debug__ is no longer illegal;
1172 instead, a warning is issued. It will become illegal in 2.2.
1173
Guido van Rossum5b08f132001-04-16 02:05:23 +00001174- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1175 "%#x" now always prepends "0x", even if the value is zero.
1176
1177- Fixed some nits in the bytecode compiler.
1178
1179- Fixed core dumps when calling certain kinds of non-functions.
1180
1181- Fixed various core dumps caused by reference count bugs.
1182
1183Build and Ports
1184
1185- Use INSTALL_SCRIPT to install script files.
1186
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001187- New port: SCO Unixware 7, by Billy G. Allie.
1188
Guido van Rossum5b08f132001-04-16 02:05:23 +00001189- Updated RISCOS port.
1190
1191- Updated BeOS port and notes.
1192
1193- Various other porting problems resolved.
1194
1195Library
1196
1197- The TERMIOS and SOCKET modules are now truly obsolete and
1198 unnecessary. Their symbols are incorporated in the termios and
1199 socket modules.
1200
1201- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1202 better tests for pickling.
1203
1204- threading: make Condition.wait() robust against KeyboardInterrupt.
1205
1206- zipfile: add support to zipfile to support opening an archive
1207 represented by an open file rather than a file name. Fix bug where
1208 the archive was not properly closed. Fixed a bug in this bugfix
1209 where flush() was called for a read-only file.
1210
1211- imputil: added an uninstall() method to the ImportManager.
1212
1213- Canvas: fixed bugs in lower() and tkraise() methods.
1214
1215- SocketServer: API change (added overridable close_request() method)
1216 so that the TCP server can explicitly close the request.
1217
1218- pstats: Eric Raymond added a simple interactive statistics browser,
1219 invoked when the module is run as a script.
1220
1221- locale: fixed a problem in format().
1222
1223- webbrowser: made it work when the BROWSER environment variable has a
1224 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1225 KDE 2. Fixed some other nits.
1226
1227- unittest: changes to allow using a different exception than
1228 AssertionError, and added a few more function aliases. Some other
1229 small changes.
1230
1231- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1232
1233- asynchat: fixed a critical bug in asynchat that slipped through the
1234 2.1b2 release. Fixed another rare bug.
1235
1236- Fix some unqualified except: clauses (always a bad code example).
1237
1238XML
1239
1240- pyexpat: new API get_version_string().
1241
1242- Fixed some minidom bugs.
1243
1244Extensions
1245
1246- Fixed a core dump in _weakref. Removed the weakref.mapping()
1247 function (it adds nothing to the API).
1248
1249- Rationalized the use of header files in the readline module, to make
1250 it compile (albeit with some warnings) with the very recent readline
1251 4.2, without breaking for earlier versions.
1252
1253- Hopefully fixed a buffering problem in linuxaudiodev.
1254
1255- Attempted a fix to make the OpenSSL support in the socket module
1256 work again with pre-0.9.5 versions of OpenSSL.
1257
1258Tests
1259
1260- Added a test case for asynchat and asyncore.
1261
1262- Removed coupling between tests where one test failing could break
1263 another.
1264
1265Tools
1266
1267- Ping added an interactive help browser to pydoc, fixed some nits
1268 in the rest of the pydoc code, and added some features to his
1269 inspect module.
1270
1271- An updated python-mode.el version 4.1 which integrates Ken
1272 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1273 much nicer in XEmacs and Emacs. When stepping through your program
1274 with pdb, in either the shell window or the *Python* window, the
1275 source file and line will be tracked by an arrow. Very cool!
1276
1277- IDLE: syntax warnings in interactive mode are changed into errors.
1278
1279- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001280 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001281
1282- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001283
Barry Warsaw11e89c72001-04-11 20:37:57 +00001284
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001285What's New in Python 2.1 beta 2?
1286================================
1287
Guido van Rossum053ae352001-03-22 14:17:21 +00001288(Unlisted are many fixed bugs, more documentation, etc.)
1289
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001290Core language, builtins, and interpreter
1291
Guido van Rossum053ae352001-03-22 14:17:21 +00001292- The nested scopes work (enabled by "from __future__ import
1293 nested_scopes") is completed; in particular, the future now extends
1294 into code executed through exec, eval() and execfile(), and into the
1295 interactive interpreter.
1296
1297- When calling a base class method (e.g. BaseClass.__init__(self)),
1298 this is now allowed even if self is not strictly spoken a class
1299 instance (e.g. when using metaclasses or the Don Beaudry hook).
1300
1301- Slice objects are now comparable but not hashable; this prevents
1302 dict[:] from being accepted but meaningless.
1303
1304- Complex division is now calculated using less braindead algorithms.
1305 This doesn't change semantics except it's more likely to give useful
1306 results in extreme cases. Complex repr() now uses full precision
1307 like float repr().
1308
1309- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1310
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001311- It is illegal to assign to the name __debug__, which is set when the
1312 interpreter starts. It is effectively a compile-time constant.
1313
1314- A warning will be issued if a global statement for a variable
1315 follows a use or assignment of that variable.
1316
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001317Standard library
1318
Guido van Rossum053ae352001-03-22 14:17:21 +00001319- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1320 inspired by JUnit), is now part of the standard library. You now
1321 have a choice of two testing frameworks: unittest requires you to
1322 write testcases as separate code, doctest gathers them from
1323 docstrings. Both approaches have their advantages and
1324 disadvantages.
1325
1326- A new module Tix was added, which wraps the Tix extension library
1327 for Tk. With that module, it is not necessary to statically link
1328 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1329 require" command. See Demo/tix/.
1330
1331- tzparse.py is now obsolete.
1332
1333- In gzip.py, the seek() and tell() methods are removed -- they were
1334 non-functional anyway, and it's better if callers can test for their
1335 existence with hasattr().
1336
1337Python/C API
1338
1339- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1340 that's already in the dictionary during a PyDict_Next() iteration.
1341 This used to fail occasionally when a dictionary resize operation
1342 could be triggered that would rehash all the keys. All other
1343 modifications to the dictionary are still off-limits during a
1344 PyDict_Next() iteration!
1345
1346- New extended APIs related to passing compiler variables around.
1347
1348- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1349 implement isinstance() and issubclass().
1350
1351- Py_BuildValue() now has a "D" conversion to create a Python complex
1352 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001353
Fred Drake4e262a92001-03-22 18:26:47 +00001354- Extensions types which support weak references must now set the
1355 field allocated for the weak reference machinery to NULL themselves;
1356 this is done to avoid the cost of checking each object for having a
1357 weakly referencable type in PyObject_INIT(), since most types are
1358 not weakly referencable.
1359
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001360- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1361 free variables and cell variables to and from the frame's f_locals.
1362
1363- Variants of several functions defined in pythonrun.h have been added
1364 to support the nested_scopes future statement. The variants all end
1365 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1366 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1367 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001368 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001369
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001370Distutils
1371
1372- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1373 into the release tree.
1374
Tim Peters0e57abf2001-05-02 07:39:38 +00001375- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001376 (an uninstaller, more customization of the installer's display)
1377
1378- from Jack Jansen: added Mac-specific code to generate a dialog for
1379 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001380 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001381 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001382
1383- added 'platforms' and 'keywords' to the set of metadata that can be
1384 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001385
1386- applied patches from Jason Tishler to make the compiler class work with
1387 Cygwin.
1388
1389
Tim Peters2fe289a2001-03-01 22:19:38 +00001390What's New in Python 2.1 beta 1?
1391================================
Tim Petersd66595f2001-02-04 03:09:53 +00001392
1393Core language, builtins, and interpreter
1394
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001395- Following an outcry from the community about the amount of code
1396 broken by the nested scopes feature introduced in 2.1a2, we decided
1397 to make this feature optional, and to wait until Python 2.2 (or at
1398 least 6 months) to make it standard. The option can be enabled on a
1399 per-module basis by adding "from __future__ import nested_scopes" at
1400 the beginning of a module (before any other statements, but after
1401 comments and an optional docstring). See PEP 236 (Back to the
1402 __future__) for a description of the __future__ statement. PEP 227
1403 (Statically Nested Scopes) has been updated to reflect this change,
1404 and to clarify the semantics in a number of endcases.
1405
1406- The nested scopes code, when enabled, has been hardened, and most
1407 bugs and memory leaks in it have been fixed.
1408
1409- Compile-time warnings are now generated for a number of conditions
1410 that will break or change in meaning when nested scopes are enabled:
1411
1412 - Using "from...import *" or "exec" without in-clause in a function
1413 scope that also defines a lambda or nested function with one or
1414 more free (non-local) variables. The presence of the import* or
1415 bare exec makes it impossible for the compiler to determine the
1416 exact set of local variables in the outer scope, which makes it
1417 impossible to determine the bindings for free variables in the
1418 inner scope. To avoid the warning about import *, change it into
1419 an import of explicitly name object, or move the import* statement
1420 to the global scope; to avoid the warning about bare exec, use
1421 exec...in... (a good idea anyway -- there's a possibility that
1422 bare exec will be deprecated in the future).
1423
1424 - Use of a global variable in a nested scope with the same name as a
1425 local variable in a surrounding scope. This will change in
1426 meaning with nested scopes: the name in the inner scope will
1427 reference the variable in the outer scope rather than the global
1428 of the same name. To avoid the warning, either rename the outer
1429 variable, or use a global statement in the inner function.
1430
Neil Schemenauera35c6882001-02-27 04:45:05 +00001431- An optional object allocator has been included. This allocator is
1432 optimized for Python objects and should be faster and use less memory
1433 than the standard system allocator. It is not enabled by default
1434 because of possible thread safety problems. The allocator is only
1435 protected by the Python interpreter lock and it is possible that some
1436 extension modules require a thread safe allocator. The object
1437 allocator can be enabled by providing the "--with-pymalloc" option to
1438 configure.
1439
Tim Petersd66595f2001-02-04 03:09:53 +00001440Standard library
1441
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001442- pyexpat now detects the expat version if expat.h defines it. A
1443 number of additional handlers are provided, which are only available
1444 since expat 1.95. In addition, the methods SetParamEntityParsing and
1445 GetInputContext of Parser objects are available with 1.95.x
1446 only. Parser objects now provide the ordered_attributes and
1447 specified_attributes attributes. A new module expat.model was added,
1448 which offers a number of additional constants if 1.95.x is used.
1449
1450- xml.dom offers the new functions registerDOMImplementation and
1451 getDOMImplementation.
1452
1453- xml.dom.minidom offers a toprettyxml method. A number of DOM
1454 conformance issues have been resolved. In particular, Element now
1455 has an hasAttributes method, and the handling of namespaces was
1456 improved.
1457
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001458- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1459 getting information about live Python code, and pydoc.py, a module
1460 for interactively converting docstrings to HTML or text.
1461 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001462 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001463 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1464 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001465
Tim Peters1eff7962001-03-01 02:31:33 +00001466- New library module difflib.py, primarily packaging the SequenceMatcher
1467 class at the heart of the popular ndiff.py file-comparison tool.
1468
1469- doctest.py (a framework for verifying Python code examples in docstrings)
1470 is now part of the std library.
1471
Tim Petersd66595f2001-02-04 03:09:53 +00001472Windows changes
1473
Guido van Rossume3955a82001-03-02 14:05:59 +00001474- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1475 small GUI that lets you browse the module docstrings using your
1476 default web browser.
1477
Tim Peters1eff7962001-03-01 02:31:33 +00001478- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1479 Platforms) is implemented. See
1480
1481 http://python.sourceforge.net/peps/pep-0235.html
1482
1483 for full details, especially the "Current Lower-Left Semantics" section.
1484 The new Windows import rules are simpler than before:
1485
1486 A. If the PYTHONCASEOK environment variable exists, same as
1487 before: silently accept the first case-insensitive match of any
1488 kind; raise ImportError if none found.
1489
1490 B. Else search sys.path for the first case-sensitive match; raise
1491 ImportError if none found.
1492
1493 The same rules have been implented on other platforms with case-
1494 insensitive but case-preserving filesystems too (including Cygwin, and
1495 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001496
Tim Peters25a9ce32001-02-19 07:06:36 +00001497- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1498 what it's supposed to do (and does do under NT and 2000) via direct
1499 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001500 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001501 all Win9x systems before.
1502
Tim Peters1eff7962001-03-01 02:31:33 +00001503- Build: Subproject _test (effectively) renamed to _testcapi.
1504
Tim Peters2fe289a2001-03-01 22:19:38 +00001505New platforms
1506
1507- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1508 Thanks to Steven Majewski!
1509
1510- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1511 Tishler!
1512
Guido van Rossum9089b272001-03-02 06:49:50 +00001513- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1514 Schwertberger! See RISCOS/README for more information -- it seems
1515 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001516 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001517
Tim Peters25a9ce32001-02-19 07:06:36 +00001518
Tim Petersd7b5e882001-01-25 03:36:26 +00001519What's New in Python 2.1 alpha 2?
1520=================================
Tim Peters40ead762001-01-27 05:35:26 +00001521
Tim Petersd7b5e882001-01-25 03:36:26 +00001522Core language, builtins, and interpreter
1523
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001524- Scopes nest. If a name is used in a function or class, but is not
1525 local, the definition in the nearest enclosing function scope will
1526 be used. One consequence of this change is that lambda statements
1527 could reference variables in the namespaces where the lambda is
1528 defined. In some unusual cases, this change will break code.
1529
1530 In all previous version of Python, names were resolved in exactly
1531 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001532 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001533 function A is defined within a function B, the names bound in B are
1534 not visible in A. The new rules make names bound in B visible in A,
1535 unless A contains a name binding that hides the binding in B.
1536
1537 Section 4.1 of the reference manual describes the new scoping rules
1538 in detail. The test script in Lib/test/test_scope.py demonstrates
1539 some of the effects of the change.
1540
1541 The new rules will cause existing code to break if it defines nested
1542 functions where an outer function has local variables with the same
1543 name as globals or builtins used by the inner function. Example:
1544
1545 def munge(str):
1546 def helper(x):
1547 return str(x)
1548 if type(str) != type(''):
1549 str = helper(str)
1550 return str.strip()
1551
1552 Under the old rules, the name str in helper() is bound to the
1553 builtin function str(). Under the new rules, it will be bound to
1554 the argument named str and an error will occur when helper() is
1555 called.
1556
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001557- The compiler will report a SyntaxError if "from ... import *" occurs
1558 in a function or class scope. The language reference has documented
1559 that this case is illegal, but the compiler never checked for it.
1560 The recent introduction of nested scope makes the meaning of this
1561 form of name binding ambiguous. In a future release, the compiler
1562 may allow this form when there is no possibility of ambiguity.
1563
Tim Peters40ead762001-01-27 05:35:26 +00001564- repr(string) is easier to read, now using hex escapes instead of octal,
1565 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1566
1567 >>> "\texample \r\n" + chr(0) + chr(255)
1568 '\texample \r\n\x00\xff' # in 2.1
1569 '\011example \015\012\000\377' # in 2.0
1570
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001571- Functions are now compared and hashed by identity, not by value, since
1572 the func_code attribute is writable.
1573
Fred Drakefb9d7122001-02-01 20:00:40 +00001574- Weak references (PEP 205) have been added. This involves a few
1575 changes in the core, an extension module (_weakref), and a Python
1576 module (weakref). The weakref module is the public interface. It
1577 includes support for "explicit" weak references, proxy objects, and
1578 mappings with weakly held values.
1579
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001580- A 'continue' statement can now appear in a try block within the body
1581 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001582 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001583
Tim Petersd7b5e882001-01-25 03:36:26 +00001584Standard library
1585
Barry Warsaw30dbd142001-01-31 22:14:01 +00001586- mailbox.py now has a new class, PortableUnixMailbox which is
1587 identical to UnixMailbox but uses a more portable scheme for
1588 determining From_ separators. Also, the constructors for all the
1589 classes in this module have a new optional `factory' argument, which
1590 is a callable used when new message classes must be instantiated by
1591 the next() method.
1592
Tim Petersd7b5e882001-01-25 03:36:26 +00001593- random.py is now self-contained, and offers all the functionality of
1594 the now-deprecated whrandom.py. See the docs for details. random.py
1595 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001596 and restoring the internal state of the generator; and jumpahead(n),
1597 for quickly forcing the internal state to be the same as if n calls to
1598 random() had been made. The latter is particularly useful for multi-
1599 threaded programs, creating one instance of the random.Random() class for
1600 each thread, then using .jumpahead() to force each instance to use a
1601 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001602
Tim Peters0de88fc2001-02-01 04:59:18 +00001603- random.py's seed() function is new. For bit-for-bit compatibility with
1604 prior releases, use the whseed function instead. The new seed function
1605 addresses two problems: (1) The old function couldn't produce more than
1606 about 2**24 distinct internal states; the new one about 2**45 (the best
1607 that can be done in the Wichmann-Hill generator). (2) The old function
1608 sometimes produced identical internal states when passed distinct
1609 integers, and there was no simple way to predict when that would happen;
1610 the new one guarantees to produce distinct internal states for all
1611 arguments in [0, 27814431486576L).
1612
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001613- The socket module now supports raw packets on Linux. The socket
1614 family is AF_PACKET.
1615
Tim Peters9ea17ac2001-02-02 05:57:15 +00001616- test_capi.py is a start at running tests of the Python C API. The tests
1617 are implemented by the new Modules/_testmodule.c.
1618
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001619- A new extension module, _symtable, provides provisional access to the
1620 internal symbol table used by the Python compiler. A higher-level
1621 interface will be added on top of _symtable in a future release.
1622
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001623- Removed the obsolete soundex module.
1624
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001625- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1626 the isSameNode method; NamedNodeMap the get method.
1627
1628- xml.sax.expatreader supports the lexical handler property; it
1629 generates comment, startCDATA, and endCDATA events.
1630
Tim Petersee826f82001-01-31 19:39:44 +00001631Windows changes
1632
1633- Build procedure: the zlib project is built in a different way that
1634 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001635 the zlib binary used. See PCbuild\readme.txt for details. Your old
1636 zlib-related directories can be deleted; you'll need to download fresh
1637 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001638
Tim Peters9ea17ac2001-02-02 05:57:15 +00001639- Build: New subproject _test for the benefit of test_capi.py (see above).
1640
Tim Petersb16c56f2001-02-02 21:24:51 +00001641- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1642 interface to some Python compiler internals).
1643
1644- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001645 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001646
Tim Petersa3a3a032000-11-30 05:22:44 +00001647What's New in Python 2.1 alpha 1?
1648=================================
1649
1650Core language, builtins, and interpreter
1651
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001652- There is a new Unicode companion to the PyObject_Str() API
1653 called PyObject_Unicode(). It behaves in the same way as the
1654 former, but assures that the returned value is an Unicode object
1655 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001656
Guido van Rossumf98eda02001-01-17 15:54:45 +00001657- The comparison operators support "rich comparison overloading" (PEP
1658 207). C extension types can provide a rich comparison function in
1659 the new tp_richcompare slot in the type object. The cmp() function
1660 and the C function PyObject_Compare() first try the new rich
1661 comparison operators before trying the old 3-way comparison. There
1662 is also a new C API PyObject_RichCompare() (which also falls back on
1663 the old 3-way comparison, but does not constrain the outcome of the
1664 rich comparison to a Boolean result).
1665
1666 The rich comparison function takes two objects (at least one of
1667 which is guaranteed to have the type that provided the function) and
1668 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1669 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1670 object, which may be NotImplemented (in which case the tp_compare
1671 slot function is used as a fallback, if defined).
1672
1673 Classes can overload individual comparison operators by defining one
1674 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001675 __ge__. There are no explicit "reflected argument" versions of
1676 these; instead, __lt__ and __gt__ are each other's reflection,
1677 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1678 reflection (similar at the C level). No other implications are
1679 made; in particular, Python does not assume that == is the Boolean
1680 inverse of !=, or that < is the Boolean inverse of >=. This makes
1681 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001682
1683 Classes or types that want to implement (in)equality tests but not
1684 the ordering operators (i.e. unordered types) should implement ==
1685 and !=, and raise an error for the ordering operators.
1686
Guido van Rossuma88479f2001-01-18 14:28:08 +00001687 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001688 Boolean; e.g. a matrix type might want to return a matrix of bits
1689 for A < B, giving elementwise comparisons. Such types should ensure
1690 that any interpretation of their value in a Boolean context raises
1691 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1692 at the C level) to always raise an exception.
1693
Guido van Rossuma88479f2001-01-18 14:28:08 +00001694- Complex numbers use rich comparisons to define == and != but raise
1695 an exception for <, <=, > and >=. Unfortunately, this also means
1696 that cmp() of two complex numbers raises an exception when the two
1697 numbers differ. Since it is not mathematically meaningful to compare
1698 complex numbers except for equality, I hope that this doesn't break
1699 too much code.
1700
Tim Peters3389f192001-02-18 08:48:49 +00001701- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001702 not defined by the language, other than that it's arbitrary but
1703 consistent (see the Reference Manual). An implementation detail changed
1704 in 2.1a1 such that None now compares less than any other object. Code
1705 relying on this new behavior (like code that relied on the previous
1706 behavior) does so at its own risk.
1707
Barry Warsaw573b5412001-01-15 20:43:18 +00001708- Functions and methods now support getting and setting arbitrarily
1709 named attributes (PEP 232). Functions have a new __dict__
1710 (a.k.a. func_dict) which hold the function attributes. Methods get
1711 and set attributes on their underlying im_func. It is a TypeError
1712 to set an attribute on a bound method.
1713
Guido van Rossum051e3352001-01-15 19:11:10 +00001714- The xrange() object implementation has been improved so that
1715 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1716 limitation that in this case len(xrange(sys.maxint)) can't be
1717 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1718 work fine as long as the index i doesn't actually reach 2**31.
1719 (Python uses regular ints for sequence and string indices; fixing
1720 that is much more work.)
1721
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001722- Two changes to from...import:
1723
Guido van Rossumba381232001-02-03 15:06:40 +00001724 1) "from M import X" now works even if (after loading module M)
1725 sys.modules['M'] is not a real module; it's basically a getattr()
1726 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001727
1728 2) "from M import *" now looks for M.__all__ to decide which names to
1729 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1730 filters out names starting with '_' as before. Whether or not
1731 __all__ exists, there's no restriction on the type of M.
1732
Guido van Rossumf61f1662001-01-10 20:13:55 +00001733- File objects have a new method, xreadlines(). This is the fastest
1734 way to iterate over all lines in a file:
1735
1736 for line in file.xreadlines():
1737 ...do something to line...
1738
1739 See the xreadlines module (mentioned below) for how to do this for
1740 other file-like objects.
1741
1742- Even if you don't use file.xreadlines(), you may expect a speedup on
1743 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001744 quite a bit in platform-specific ways: on systems (like Linux) that
1745 support flockfile(), getc_unlocked(), and funlockfile(), those are
1746 used by default. On systems (like Windows) without getc_unlocked(),
1747 a complicated (but still thread-safe) method using fgets() is used by
1748 default.
1749
Tim Petersd52269b2001-01-25 06:23:18 +00001750 You can force use of the fgets() method by #define'ing
1751 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001752 getc_unlocked()).
1753
Tim Petersd52269b2001-01-25 06:23:18 +00001754 You can force fgets() not to be used by #define'ing
1755 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001756 test_bufio.py fails -- and let us know if it does!).
1757
1758- In addition, the fileinput module, while still slower than the other
1759 methods on most platforms, has been sped up too, by using
1760 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001761
1762- Support for run-time warnings has been added, including a new
1763 command line option (-W) to specify the disposition of warnings.
1764 See the description of the warnings module below.
1765
1766- Extensive changes have been made to the coercion code. This mostly
1767 affects extension modules (which can now implement mixed-type
1768 numerical operators without having to use coercion), but
1769 occasionally, in boundary cases the coercion semantics have changed
1770 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001771 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001772 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001773 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001774
Guido van Rossumf98eda02001-01-17 15:54:45 +00001775- In connection with the coercion changes, a new built-in singleton
1776 object, NotImplemented is defined. This can be returned for
1777 operations that wish to indicate they are not implemented for a
1778 particular combination of arguments. From C, this is
1779 Py_NotImplemented.
1780
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001781- The interpreter accepts now bytecode files on the command line even
1782 if they do not have a .pyc or .pyo extension. On Linux, after executing
1783
Martin v. Löwise214baa2001-02-04 22:37:56 +00001784import imp,sys,string
1785magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1786reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1787open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001788
1789 any byte code file can be used as an executable (i.e. as an argument
1790 to execve(2)).
1791
Tim Peters9940b802000-12-01 07:59:35 +00001792- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001793 character. In 1.6 and earlier, they never produced a sign,
1794 and raised an error if the value of the long was too large
1795 to fit in a Python int. In 2.0, they produced a sign if and
1796 only if too large to fit in an int. This was inconsistent
1797 across platforms (because the size of an int varies across
1798 platforms), and inconsistent with hex() and oct(). Example:
1799
1800 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001801 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001802 'ffffffbe' # in 2.0 and before, on 32-bit machines
1803 >>> hex(-0x42L)
1804 '-0x42L' # in all versions of Python
1805
Tim Peters9940b802000-12-01 07:59:35 +00001806 The behavior of %d formats for negative Python longs remains
1807 the same as in 2.0 (although in 1.6 and before, they raised
1808 an error if the long didn't fit in a Python int).
1809
1810 %u formats don't make sense for Python longs, but are allowed
1811 and treated the same as %d in 2.1. In 2.0, a negative long
1812 formatted via %u produced a sign if and only if too large to
1813 fit in an int. In 1.6 and earlier, a negative long formatted
1814 via %u raised an error if it was too big to fit in an int.
1815
Guido van Rossum3661d392000-12-12 22:10:31 +00001816- Dictionary objects have an odd new method, popitem(). This removes
1817 an arbitrary item from the dictionary and returns it (in the form of
1818 a (key, value) pair). This can be useful for algorithms that use a
1819 dictionary as a bag of "to do" items and repeatedly need to pick one
1820 item. Such algorithms normally end up running in quadratic time;
1821 using popitem() they can usually be made to run in linear time.
1822
Tim Peters36cdad12000-12-29 02:06:45 +00001823Standard library
1824
Thomas Woutersfe385252001-01-19 23:16:56 +00001825- In the time module, the time argument to the functions strftime,
1826 localtime, gmtime, asctime and ctime is now optional, defaulting to
1827 the current time (in the local timezone).
1828
Guido van Rossumda91f222001-01-15 16:36:08 +00001829- The ftplib module now defaults to passive mode, which is deemed a
1830 more useful default given that clients are often inside firewalls
1831 these days. Note that this could break if ftplib is used to connect
1832 to a *server* that is inside a firewall, from outside; this is
1833 expected to be a very rare situation. To fix that, you can call
1834 ftp.set_pasv(0).
1835
Martin v. Löwis10a27872001-01-13 09:54:41 +00001836- The module site now treats .pth files not only for path configuration,
1837 but also supports extensions to the initialization code: Lines starting
1838 with import are executed.
1839
Guido van Rossumf61f1662001-01-10 20:13:55 +00001840- There's a new module, warnings, which implements a mechanism for
1841 issuing and filtering warnings. There are some new built-in
1842 exceptions that serve as warning categories, and a new command line
1843 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1844 turns warnings into errors). warnings.warn(message[, category])
1845 issues a warning message; this can also be called from C as
1846 PyErr_Warn(category, message).
1847
1848- A new module xreadlines was added. This exports a single factory
1849 function, xreadlines(). The intention is that this code is the
1850 absolutely fastest way to iterate over all lines in an open
1851 file(-like) object:
1852
1853 import xreadlines
1854 for line in xreadlines.xreadlines(file):
1855 ...do something to line...
1856
1857 This is equivalent to the previous the speed record holder using
1858 file.readlines(sizehint). Note that if file is a real file object
1859 (as opposed to a file-like object), this is equivalent:
1860
1861 for line in file.xreadlines():
1862 ...do something to line...
1863
Tim Peters36cdad12000-12-29 02:06:45 +00001864- The bisect module has new functions bisect_left, insort_left,
1865 bisect_right and insort_right. The old names bisect and insort
1866 are now aliases for bisect_right and insort_right. XXX_right
1867 and XXX_left methods differ in what happens when the new element
1868 compares equal to one or more elements already in the list: the
1869 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001870 right. Code that doesn't care where equal elements end up should
1871 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001872
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001873- The new curses.panel module wraps the panel library that forms part
1874 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1875
Guido van Rossumf61f1662001-01-10 20:13:55 +00001876- The SocketServer module now sets the allow_reuse_address flag by
1877 default in the TCPServer class.
1878
1879- A new function, sys._getframe(), returns the stack frame pointer of
1880 the caller. This is intended only as a building block for
1881 higher-level mechanisms such as string interpolation.
1882
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001883- The pyexpat module supports a number of new handlers, which are
1884 available only in expat 1.2. If invocation of a callback fails, it
1885 will report an additional frame in the traceback. Parser objects
1886 participate now in garbage collection. If expat reports an unknown
1887 encoding, pyexpat will try to use a Python codec; that works only
1888 for single-byte charsets. The parser type objects is exposed as
1889 XMLParserObject.
1890
1891- xml.dom now offers standard definitions for symbolic node type and
1892 exception code constants, and a hierarchy of DOM exceptions. minidom
1893 was adjusted to use them.
1894
1895- The conformance of xml.dom.minidom to the DOM specification was
1896 improved. It detects a number of additional error cases; the
1897 previous/next relationship works even when the tree is modified;
1898 Node supports the normalize() method; NamedNodeMap, DocumentType and
1899 DOMImplementation classes were added; Element supports the
1900 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1901 method.
1902
Guido van Rossumf61f1662001-01-10 20:13:55 +00001903Build issues
1904
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001905- For Unix (and Unix-compatible) builds, configuration and building of
1906 extension modules is now greatly automated. Rather than having to
1907 edit the Modules/Setup file to indicate which modules should be
1908 built and where their include files and libraries are, a
1909 distutils-based setup.py script now takes care of building most
1910 extension modules. All extension modules built this way are built
1911 as shared libraries. Only a few modules that must be linked
1912 statically are still listed in the Setup file; you won't need to
1913 edit their configuration.
1914
1915- Python should now build out of the box on Cygwin. If it doesn't,
1916 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001917
1918- Python now always uses its own (renamed) implementation of getopt()
1919 -- there's too much variation among C library getopt()
1920 implementations.
1921
1922- C++ compilers are better supported; the CXX macro is always set to a
1923 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001924
Tim Petersd92dfe02000-12-12 01:18:41 +00001925Windows changes
1926
1927- select module: By default under Windows, a select() call
1928 can specify no more than 64 sockets. Python now boosts
1929 this Microsoft default to 512. If you need even more than
1930 that, see the MS docs (you'll need to #define FD_SETSIZE
1931 and recompile Python from source).
1932
Guido van Rossumf61f1662001-01-10 20:13:55 +00001933- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1934 subdirectory is no more!
1935
Tim Petersa3a3a032000-11-30 05:22:44 +00001936
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001937What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001938=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001939
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001940Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001941changes are in the file HISTORY. If you are making the jump directly
1942from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1943HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001944
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001945Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1946the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1947http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001948
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001949--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001950
1951======================================================================
1952
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001953What's new in 2.0 (since release candidate 1)?
1954==============================================
1955
1956Standard library
1957
1958- The copy_reg module was modified to clarify its intended use: to
1959 register pickle support for extension types, not for classes.
1960 pickle() will raise a TypeError if it is passed a class.
1961
1962- Fixed a bug in gettext's "normalize and expand" code that prevented
1963 it from finding an existing .mo file.
1964
1965- Restored support for HTTP/0.9 servers in httplib.
1966
Tim Peters989b7b92000-10-16 20:24:53 +00001967- The math module was changed to stop raising OverflowError in case of
1968 underflow, and return 0 instead in underflow cases. Whether Python
1969 used to raise OverflowError in case of underflow was platform-
1970 dependent (it did when the platform math library set errno to ERANGE
1971 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001972
1973- Fixed a bug in StringIO that occurred when the file position was not
1974 at the end of the file and write() was called with enough data to
1975 extend past the end of the file.
1976
1977- Fixed a bug that caused Tkinter error messages to get lost on
1978 Windows. The bug was fixed by replacing direct use of
1979 interp->result with Tcl_GetStringResult(interp).
1980
1981- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1982 redirect response.
1983
1984- Several changes were made to distutils: Some debugging code was
1985 removed from util. Fixed the installer used when an external zip
1986 program (like WinZip) is not found; the source code for this
1987 installer is in Misc/distutils. check_lib() was modified to behave
1988 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1989 test for whether installed modules are on sys.path was changed to
1990 use both normcase() and normpath().
1991
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001992- Several minor bugs were fixed in the xml package (the minidom,
1993 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001994
1995- The regression test driver (regrtest.py) behavior when invoked with
1996 -l changed: It now reports a count of objects that are recognized as
1997 garbage but not freed by the garbage collector.
1998
Tim Peters989b7b92000-10-16 20:24:53 +00001999- The regression test for the math module was changed to test
2000 exceptional behavior when the test is run in verbose mode. Python
2001 cannot yet guarantee consistent exception behavior across platforms,
2002 so the exception part of test_math is run only in verbose mode, and
2003 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002004
2005Internals
2006
2007- PyOS_CheckStack() has been disabled on Win64, where it caused
2008 test_sre to fail.
2009
2010Build issues
2011
2012- Changed compiler flags, so that gcc is always invoked with -Wall and
2013 -Wstrict-prototypes. Users compiling Python with GCC should see
2014 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002015 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002016 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002017
Tim Petersa3a3a032000-11-30 05:22:44 +00002018- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002019
2020Tools and other miscellany
2021
2022- The compiler in Tools/compiler was updated to support the new
2023 language features introduced in 2.0: extended print statement, list
2024 comprehensions, and augmented assignments. The new compiler should
2025 also be backwards compatible with Python 1.5.2; the compiler will
2026 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002027 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002028
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002029What's new in 2.0 release candidate 1 (since beta 2)?
2030=====================================================
2031
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002032What is release candidate 1?
2033
2034We believe that release candidate 1 will fix all known bugs that we
2035intend to fix for the 2.0 final release. This release should be a bit
2036more stable than the previous betas. We would like to see even more
2037widespread testing before the final release, so we are producing this
2038release candidate. The final release will be exactly the same unless
2039any show-stopping (or brown bag) bugs are found by testers of the
2040release candidate.
2041
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002042All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002043to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002044
2045Core language, builtins, and interpreter
2046
2047- A bug that caused crashes when __coerce__ was used with augmented
2048 assignment, e.g. +=, was fixed.
2049
2050- Raise ZeroDivisionError when raising zero to a negative number,
2051 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2052 power operator and the result of math.pow(0.0, -2.0) will vary by
2053 platform. On Linux, it raises a ValueError.
2054
2055- A bug in Unicode string interpolation was fixed that occasionally
2056 caused errors with formats including "%%". For example, the
2057 following expression "%% %s" % u"abc" no longer raises a TypeError.
2058
2059- Compilation of deeply nested expressions raises MemoryError instead
2060 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2061
2062- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2063 rendering them useless. They are now written in binary mode again.
2064
2065Standard library
2066
2067- Keyword arguments are now accepted for most pattern and match object
2068 methods in SRE, the standard regular expression engine.
2069
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002070- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002071 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002072
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002073- Several bugs in the Unicode handling and error handling in _tkinter
2074 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002075
2076- Fix memory management errors in Merge() and Tkapp_Call() routines.
2077
2078- Several changes were made to cStringIO to make it compatible with
2079 the file-like object interface and with StringIO. If operations are
2080 performed on a closed object, an exception is raised. The truncate
2081 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002082 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002083
2084- There were many changes made to the linuxaudiodev module and its
2085 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002086 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002087
2088 Note that this module is named poorly, because it should work
2089 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002090 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002091
2092 The module now raises exceptions when errors occur instead of
2093 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2094 audio) and defines a getptr() method that calls the
2095 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2096
2097- The library_version attribute, introduced in an earlier beta, was
2098 removed because it can not be supported with early versions of the C
2099 readline library, which provides no way to determine the version at
2100 compile-time.
2101
2102- The binascii module is now enabled on Win64.
2103
Tim Peters46446d62000-10-09 21:19:31 +00002104- tokenize.py no longer suffers "recursion depth" errors when parsing
2105 programs with very long string literals.
2106
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002107Internals
2108
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002109- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002110 which is called when the interpreter starts up to determine where
2111 the standard library is installed. These vulnerabilities affect all
2112 previous versions of Python and can be exploited by setting very
2113 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2114 setuid Python script, although use of the wrapper in
2115 Misc/setuid-prog.c will eliminate the vulnerability.
2116
2117- Fixed garbage collection bugs in instance creation that were
2118 triggered when errors occurred during initialization. The solution,
2119 applied in cPickle and in PyInstance_New(), is to call
2120 PyObject_GC_Init() after the initialization of the object's
2121 container attributes is complete.
2122
2123- pyexpat adds definitions of PyModule_AddStringConstant and
2124 PyModule_AddObject if the Python version is less than 2.0, which
2125 provides compatibility with PyXML on Python 1.5.2.
2126
2127- If the platform has a bogus definition for LONG_BIT (the number of
2128 bits in a long), an error will be reported at compile time.
2129
2130- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2131 collection crashes and possibly other, unreported crashes.
2132
2133- Fixed a memory leak in _PyUnicode_Fini().
2134
2135Build issues
2136
2137- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002138 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002139 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002140
2141- The mmap.PAGESIZE constant is now initialized using sysconf when
2142 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2143
2144- The md5 file should now compile on all platforms.
2145
2146- The select module now compiles on platforms that do not define
2147 POLLRDNORM and related constants.
2148
2149- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002150 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002151
Jeremy Hylton10921202000-10-09 18:34:12 +00002152- BeOS: A number of changes were made to the build and installation
2153 process. ar-fake now operates on a directory of object files.
2154 dl_export.h is gone, and its macros now appear on the mwcc command
2155 line during build on PPC BeOS.
2156
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002157- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002158 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002159
2160- Cygwin: Support for shared libraries, Tkinter, and sockets.
2161
2162- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2163
2164Tools and other miscellany
2165
2166- Removed debugging prints from main used with freeze.
2167
Tim Peters46446d62000-10-09 21:19:31 +00002168- IDLE auto-indent no longer crashes when it encounters Unicode
2169 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002170
2171What's new in 2.0 beta 2 (since beta 1)?
2172========================================
2173
2174Core language, builtins, and interpreter
2175
Tim Peters482c0212000-09-26 06:33:09 +00002176- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002177 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002178
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002179- Add -h and -V command line options to print the usage message and
2180 Python version number and exit immediately.
2181
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002182- eval() and exec accept Unicode objects as code parameters.
2183
2184- getattr() and setattr() now also accept Unicode objects for the
2185 attribute name, which are converted to strings using the default
2186 encoding before lookup.
2187
2188- Multiplication on string and Unicode now does proper bounds
2189 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2190 string is too long."
2191
2192- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002193 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002194
Jeremy Hylton1b618592000-09-26 05:32:36 +00002195
2196Standard library and extensions
2197
Guido van Rossum5b08f132001-04-16 02:05:23 +00002198- socket module: the OpenSSL code now adds support for RAND_status()
2199 and EGD (Entropy Gathering Device).
2200
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002201- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002202 argument checking; it still takes no arguments.
2203
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002204- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002205
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002206- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002207
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002208- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002209
2210- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002211 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002212
2213- copy: Copy Unicode objects atomically.
2214
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002215- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002216
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002217- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002218
Fred Drake67233bc2000-09-26 16:40:27 +00002219- dbm: Add get() and setdefault() methods to dbm object. Add constant
2220 `library' to module that names the library used. Added doc strings
2221 and method names to error messages. Uses configure to determine
2222 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2223 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002224
2225- distutils: Update to version 0.9.3.
2226
2227- dl: Add several dl.RTLD_ constants.
2228
2229- fpectl: Now supported on FreeBSD.
2230
2231- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2232 found by the collector will be saved in gc.garbage. This is useful
2233 for debugging a program that creates reference cycles.
2234
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002235- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002236 of HTTP class. Do not close socket on zero-length response. Do not
2237 crash when server sends invalid content-length header.
2238
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002239- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002240
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002241- marshal: When reading a short, sign-extend on platforms where shorts
2242 are bigger than 16 bits. When reading a long, repair the unportable
2243 sign extension that was being done for 64-bit machines. (It assumed
2244 that signed right shift sign-extends.)
2245
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002246- operator: Add contains(), invert(), __invert__() as aliases for
2247 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002248
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002249- os: Add support for popen2() and popen3() on all platforms where
2250 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002251
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002252- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002253 clicking on a file in Explorer (or passing the file name to the
2254 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002255
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002256- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002257 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002258
2259- pickle: Now raises ValueError when an invalid pickle that contains
2260 a non-string repr where a string repr was expected. This behavior
2261 matches cPickle.
2262
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002263- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002264
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002265- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002266
2267- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002268 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002269 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002270
2271- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002272 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002273
2274- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002275 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002276 few cycles during startup since the first call to
2277 setdefaultencoding() will initialize the codec registry and the
2278 encodings package.
2279
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002280- socket: Support for size hint in readlines() method of object returned
2281 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002282
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002283- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002284 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002285 is followed by whitespace.
2286
Tim Petersa3a3a032000-11-30 05:22:44 +00002287- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002288
2289- struct: Check ranges for bytes and shorts.
2290
2291- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002292 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002293
2294- Tkinter: Image objects are now guaranteed to have unique ids. Set
2295 event.delta to zero if Tk version doesn't support mousewheel.
2296 Removed some debugging prints.
2297
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002298- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002299
Fred Drake67233bc2000-09-26 16:40:27 +00002300- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002301 which works around a bug in Norton AntiVirus 2000 that leads directly
2302 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002303
2304- xml: New version detection code allows PyXML to override standard
2305 XML package if PyXML version is greater than 0.6.1.
2306
Fred Drake64bb3802000-09-26 16:21:35 +00002307- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2308 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2309 tree only for nodes which are sufficiently interesting to a specific
2310 application. Does not provide the HTML-specific extensions. Still
2311 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002312
Fred Drake64bb3802000-09-26 16:21:35 +00002313- xml.sax: SAX 2 support for Python, including all the handler
2314 interfaces needed to process XML 1.0 compliant XML. Some
2315 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002316
Fred Drake64bb3802000-09-26 16:21:35 +00002317- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2318 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002319
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002320
Jeremy Hylton1b618592000-09-26 05:32:36 +00002321C API
2322
2323- Add three new convenience functions for module initialization --
2324 PyModule_AddObject(), PyModule_AddIntConstant(), and
2325 PyModule_AddStringConstant().
2326
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002327- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002328 removed and add #error to Python.h if NULL isn't defined after
2329 #include of stdio.h.
2330
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002331- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002332 backwards compatibility (at the source level) with old extensions.
2333
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002334- A wrapper API was added for signal() and sigaction(). Instead of
2335 either function, always use PyOS_getsig() to get a signal handler
2336 and PyOS_setsig() to set one. A new convenience typedef
2337 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002338
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002339- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002340 internal data buffer and size of a string object -- or the default
2341 encoded version of a Unicode object.
2342
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002343- PyString_Size() and PyString_AsString() accept Unicode objects.
2344
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002345- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002346 exists). INT_MAX and LONG_MAX will always be defined, even if
2347 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002348
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002349- PyFloat_FromString takes a second argument, pend, that was
2350 effectively useless. It is now officially useless but preserved for
2351 backwards compatibility. If the pend argument is not NULL, *pend is
2352 set to NULL.
2353
2354- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2355 for the attribute name. See note on getattr() above.
2356
2357- A few bug fixes to argument processing for Unicode.
2358 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2359 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2360 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002361 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002362
2363- Py_BuildValue accepts B format (for bgen-generated code).
2364
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002365
Jeremy Hylton1b618592000-09-26 05:32:36 +00002366Internals
2367
2368- On Unix, fix code for finding Python installation directory so that
2369 it works when argv[0] is a relative path.
2370
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002371- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002372 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002373 rather than by generating a copy of the object.
2374
Tim Peters482c0212000-09-26 06:33:09 +00002375- Several of the internal Unicode tables are much smaller now, and
2376 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002377
Jeremy Hylton97693b02000-09-26 17:42:51 +00002378- In the garbage collector: Fixed bug in collection of tuples. Fixed
2379 bug that caused some instances to be removed from the container set
2380 while they were still live. Fixed parsing in gc.set_debug() for
2381 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002382
2383- Fixed refcount problem in instance deallocation that only occurred
2384 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2385
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002386- On Windows, getpythonregpath is now protected against null data in
2387 registry key.
2388
2389- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002390 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002391
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002392
Jeremy Hylton1b618592000-09-26 05:32:36 +00002393Build and platform-specific issues
2394
2395- Better support of GNU Pth via --with-pth configure option.
2396
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002397- Python/C API now properly exposed to dynamically-loaded extension
2398 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002399
2400- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2401 Don't define MS_SYNC to be zero when it is undefined. Added missing
2402 prototypes in posixmodule.c.
2403
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002404- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002405 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002406
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002407- Fix largefile support on older NetBSD systems and OpenBSD by adding
2408 define for TELL64.
2409
2410
2411Tools and other miscellany
2412
2413- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2414
2415- freeze: The modulefinder now works with 2.0 opcodes.
2416
Tim Petersa3a3a032000-11-30 05:22:44 +00002417- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002418 Move hackery of sys.argv until after the Tk instance has been
2419 created, which allows the application-specific Tkinter
2420 initialization to be executed if present; also pass an explicit
2421 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002422
Jeremy Hylton1b618592000-09-26 05:32:36 +00002423
2424What's new in 2.0 beta 1?
2425=========================
2426
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002427Source Incompatibilities
2428------------------------
2429
2430None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2431such as single-argument append(), connect() and bind(), and changes to
2432str(long) and repr(float).
2433
2434
2435Binary Incompatibilities
2436------------------------
2437
2438- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2439with Python 2.0; these extensions will have to be rebuilt for Python
24402.0.
2441
2442- On Windows, attempting to import a third party extension built for
2443Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2444can do about this. Check your PYTHONPATH environment variable!
2445
2446- Python bytecode files (*.pyc and *.pyo) are not compatible between
2447releases.
2448
2449
2450Overview of Changes Since 1.6
2451-----------------------------
2452
2453There are many new modules (including brand new XML support through
2454the xml package, and i18n support through the gettext module); a list
2455of all new modules is included below. Lots of bugs have been fixed.
2456
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002457The process for making major new changes to the language has changed
2458since Python 1.6. Enhancements must now be documented by a Python
2459Enhancement Proposal (PEP) before they can be accepted.
2460
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002461There are several important syntax enhancements, described in more
2462detail below:
2463
2464 - Augmented assignment, e.g. x += 1
2465
2466 - List comprehensions, e.g. [x**2 for x in range(10)]
2467
2468 - Extended import statement, e.g. import Module as Name
2469
2470 - Extended print statement, e.g. print >> file, "Hello"
2471
2472Other important changes:
2473
2474 - Optional collection of cyclical garbage
2475
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002476Python Enhancement Proposal (PEP)
2477---------------------------------
2478
2479PEP stands for Python Enhancement Proposal. A PEP is a design
2480document providing information to the Python community, or describing
2481a new feature for Python. The PEP should provide a concise technical
2482specification of the feature and a rationale for the feature.
2483
2484We intend PEPs to be the primary mechanisms for proposing new
2485features, for collecting community input on an issue, and for
2486documenting the design decisions that have gone into Python. The PEP
2487author is responsible for building consensus within the community and
2488documenting dissenting opinions.
2489
2490The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002491
2492Augmented Assignment
2493--------------------
2494
2495This must have been the most-requested feature of the past years!
2496Eleven new assignment operators were added:
2497
Guido van Rossume905e952000-09-05 12:42:46 +00002498 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002499
2500For example,
2501
2502 A += B
2503
2504is similar to
2505
2506 A = A + B
2507
2508except that A is evaluated only once (relevant when A is something
2509like dict[index].attr).
2510
2511However, if A is a mutable object, A may be modified in place. Thus,
2512if A is a number or a string, A += B has the same effect as A = A+B
2513(except A is only evaluated once); but if a is a list, A += B has the
2514same effect as A.extend(B)!
2515
2516Classes and built-in object types can override the new operators in
2517order to implement the in-place behavior; the not-in-place behavior is
2518used automatically as a fallback when an object doesn't implement the
2519in-place behavior. For classes, the method name is derived from the
2520method name for the corresponding not-in-place operator by inserting
2521an 'i' in front of the name, e.g. __iadd__ implements in-place
2522__add__.
2523
2524Augmented assignment was implemented by Thomas Wouters.
2525
2526
2527List Comprehensions
2528-------------------
2529
2530This is a flexible new notation for lists whose elements are computed
2531from another list (or lists). The simplest form is:
2532
2533 [<expression> for <variable> in <sequence>]
2534
Guido van Rossum56db0952000-09-06 23:34:25 +00002535For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002536This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002537
2538You can also add a condition:
2539
2540 [<expression> for <variable> in <sequence> if <condition>]
2541
2542For example, [w for w in words if w == w.lower()] would yield the list
2543of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002544than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002545
2546You can also have nested for loops and more than one 'if' clause. For
2547example, here's a function that flattens a sequence of sequences::
2548
2549 def flatten(seq):
2550 return [x for subseq in seq for x in subseq]
2551
2552 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2553
2554This prints
2555
2556 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2557
2558List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002559Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002560
2561
2562Extended Import Statement
2563-------------------------
2564
2565Many people have asked for a way to import a module under a different
2566name. This can be accomplished like this:
2567
2568 import foo
2569 bar = foo
2570 del foo
2571
2572but this common idiom gets old quickly. A simple extension of the
2573import statement now allows this to be written as follows:
2574
2575 import foo as bar
2576
2577There's also a variant for 'from ... import':
2578
2579 from foo import bar as spam
2580
2581This also works with packages; e.g. you can write this:
2582
2583 import test.regrtest as regrtest
2584
2585Note that 'as' is not a new keyword -- it is recognized only in this
2586context (this is only possible because the syntax for the import
2587statement doesn't involve expressions).
2588
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002589Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002590
2591
2592Extended Print Statement
2593------------------------
2594
2595Easily the most controversial new feature, this extension to the print
2596statement adds an option to make the output go to a different file
2597than the default sys.stdout.
2598
2599For example, to write an error message to sys.stderr, you can now
2600write:
2601
2602 print >> sys.stderr, "Error: bad dog!"
2603
2604As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002605evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002606
2607 print >> None, "Hello world"
2608
2609is equivalent to
2610
2611 print "Hello world"
2612
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002613Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002614
2615
2616Optional Collection of Cyclical Garbage
2617---------------------------------------
2618
2619Python is now equipped with a garbage collector that can hunt down
2620cyclical references between Python objects. It's no replacement for
2621reference counting; in fact, it depends on the reference counts being
2622correct, and decides that a set of objects belong to a cycle if all
2623their reference counts can be accounted for from their references to
2624each other. This devious scheme was first proposed by Eric Tiedemann,
2625and brought to implementation by Neil Schemenauer.
2626
2627There's a module "gc" that lets you control some parameters of the
2628garbage collection. There's also an option to the configure script
2629that lets you enable or disable the garbage collection. In 2.0b1,
2630it's on by default, so that we (hopefully) can collect decent user
2631experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002632performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002633off by default in the final 2.0 release.
2634
2635
2636Smaller Changes
2637---------------
2638
2639A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2640map(None, seq1, seq2, ...) when the sequences have the same length;
2641i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2642the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002643zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002644
2645sys.version_info is a tuple (major, minor, micro, level, serial).
2646
2647Dictionaries have an odd new method, setdefault(key, default).
2648dict.setdefault(key, default) returns dict[key] if it exists; if not,
2649it sets dict[key] to default and returns that value. Thus:
2650
2651 dict.setdefault(key, []).append(item)
2652
2653does the same work as this common idiom:
2654
2655 if not dict.has_key(key):
2656 dict[key] = []
2657 dict[key].append(item)
2658
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002659There are two new variants of SyntaxError that are raised for
2660indentation-related errors: IndentationError and TabError.
2661
2662Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2663escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002664
2665The limits on the size of expressions and file in Python source code
2666have been raised from 2**16 to 2**32. Previous versions of Python
2667were limited because the maximum argument size the Python VM accepted
2668was 2**16. This limited the size of object constructor expressions,
2669e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2670limit was raised thanks to a patch by Charles Waldman that effectively
2671fixes the problem. It is now much more likely that you will be
2672limited by available memory than by an arbitrary limit in Python.
2673
2674The interpreter's maximum recursion depth can be modified by Python
2675programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2676limit is the maximum number of recursive calls that can be made by
2677Python code. The limit exists to prevent infinite recursion from
2678overflowing the C stack and causing a core dump. The default value is
26791000. The maximum safe value for a particular platform can be found
2680by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002681
2682New Modules and Packages
2683------------------------
2684
2685atexit - for registering functions to be called when Python exits.
2686
2687imputil - Greg Stein's alternative API for writing custom import
2688hooks.
2689
2690pyexpat - an interface to the Expat XML parser, contributed by Paul
2691Prescod.
2692
2693xml - a new package with XML support code organized (so far) in three
2694subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2695would fill a volume. There's a special feature whereby a
2696user-installed package named _xmlplus overrides the standard
2697xmlpackage; this is intended to give the XML SIG a hook to distribute
2698backwards-compatible updates to the standard xml package.
2699
2700webbrowser - a platform-independent API to launch a web browser.
2701
2702
Guido van Rossume905e952000-09-05 12:42:46 +00002703Changed Modules
2704---------------
2705
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002706array -- new methods for array objects: count, extend, index, pop, and
2707remove
2708
2709binascii -- new functions b2a_hex and a2b_hex that convert between
2710binary data and its hex representation
2711
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002712calendar -- Many new functions that support features including control
2713over which day of the week is the first day, returning strings instead
2714of printing them. Also new symbolic constants for days of week,
2715e.g. MONDAY, ..., SUNDAY.
2716
2717cgi -- FieldStorage objects have a getvalue method that works like a
2718dictionary's get method and returns the value attribute of the object.
2719
2720ConfigParser -- The parser object has new methods has_option,
2721remove_section, remove_option, set, and write. They allow the module
2722to be used for writing config files as well as reading them.
2723
2724ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002725optionally support the RFC 959 REST command.
2726
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002727gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002728
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002729httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2730the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002731
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002732locale -- implement getdefaultlocale for Win32 and Macintosh
2733
2734marshal -- no longer dumps core when marshaling deeply nested or
2735recursive data structures
2736
2737os -- new functions isatty, seteuid, setegid, setreuid, setregid
2738
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002739os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2740support under Unix.
2741
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002742os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002743
2744os.path -- fix semantics of os.path.commonprefix
2745
2746smtplib -- support for sending very long messages
2747
2748socket -- new function getfqdn()
2749
2750readline -- new functions to read, write and truncate history files.
2751The readline section of the library reference manual contains an
2752example.
2753
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002754select -- add interface to poll system call
2755
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002756shutil -- new copyfileobj function
2757
2758SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2759HTTP server.
2760
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002761Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002762
2763urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002764e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002765
2766whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002767
2768
2769Obsolete Modules
2770----------------
2771
2772None. However note that 1.6 made a whole slew of modules obsolete:
2773stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2774poly, zmod, strop, util, whatsound.
2775
2776
2777Changed, New, Obsolete Tools
2778----------------------------
2779
Tim Peters8b092332000-09-05 20:15:25 +00002780None.
Guido van Rossume905e952000-09-05 12:42:46 +00002781
2782
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002783C-level Changes
2784---------------
2785
2786Several cleanup jobs were carried out throughout the source code.
2787
2788All C code was converted to ANSI C; we got rid of all uses of the
2789Py_PROTO() macro, which makes the header files a lot more readable.
2790
2791Most of the portability hacks were moved to a new header file,
2792pyport.h; several other new header files were added and some old
2793header files were removed, in an attempt to create a more rational set
2794of header files. (Few of these ever need to be included explicitly;
2795they are all included by Python.h.)
2796
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002797Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002798and Win64, especially for the new Intel Itanium processor. Mick also
2799added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002800
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002801The C APIs to return an object's size have been update to consistently
2802use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2803previous versions, the abstract interfaces used PyXXX_Length and the
2804concrete interfaces used PyXXX_Size. The old names,
2805e.g. PyObject_Length, are still available for backwards compatibility
2806at the API level, but are deprecated.
2807
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002808The PyOS_CheckStack function has been implemented on Windows by
2809Fredrik Lundh. It prevents Python from failing with a stack overflow
2810on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002811
2812The GC changes resulted in creation of two new slots on object,
2813tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002814the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002815
2816The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002817C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002818
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002819PyErr_Format has been updated to automatically calculate the size of
2820the buffer needed to hold the formatted result string. This change
2821prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002822
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002823New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002824
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002825PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2826that are the same as their non-Ex counterparts except they take an
2827extra flag argument that tells them to close the file when done.
2828
2829XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002830
Tim Peters8b092332000-09-05 20:15:25 +00002831
2832Windows Changes
2833---------------
2834
2835New popen2/popen3/peopen4 in os module (see Changed Modules above).
2836
2837os.popen is much more usable on Windows 95 and 98. See Microsoft
2838Knowledge Base article Q150956. The Win9x workaround described there
2839is implemented by the new w9xpopen.exe helper in the root of your
2840Python installation. Note that Python uses this internally; it is not
2841a standalone program.
2842
2843Administrator privileges are no longer required to install Python
2844on Windows NT or Windows 2000. If you have administrator privileges,
2845Python's registry info will be written under HKEY_LOCAL_MACHINE.
2846Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002847under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002848uses of Python, but will prevent some advanced uses from working
2849(for example, running a Python script as an NT service, or possibly
2850from CGI).
2851
2852[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2853installer; instead, it installs the needed Tcl/Tk files directly in the
2854Python directory. If you already have a Tcl/Tk installation, this
2855wastes some disk space (about 4 Megs) but avoids problems with
2856conflicting Tcl/Tk installations, and makes it much easier for Python
2857to ensure that Tcl/Tk can find all its files.
2858
2859[This was new in 1.6] The Windows installer now installs by default in
2860\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2861
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002862
2863Updates to the changes between 1.5.2 and 1.6
2864--------------------------------------------
2865
2866The 1.6 NEWS file can't be changed after the release is done, so here
2867is some late-breaking news:
2868
2869New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2870and changes to getlocale() and setlocale().
2871
2872The new module is now enabled per default.
2873
2874It is not true that the encodings codecs cannot be used for normal
2875strings: the string.encode() (which is also present on 8-bit strings
2876!) allows using them for 8-bit strings too, e.g. to convert files from
2877cp1252 (Windows) to latin-1 or vice-versa.
2878
2879Japanese codecs are available from Tamito KAJIYAMA:
2880http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2881
2882
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002883======================================================================