blob: a9f5a9915fac85facd73760cdca370c99716a142 [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
Tim Peters75335872001-11-03 19:35:43 +000054- Symbolic group names in regular expressions must be unique. For
55 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
56 single name can't mean both "group 1" and "group 2" simultaneously.
57 Python 2.2 detects this error at regexp compilation time; previously,
58 the error went undetected, and results were unpredictable.
59
Martin v. Löwisb7b32602001-11-02 23:48:20 +000060- Tix exposes more commands through the classes DirSelectBox,
61 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
62 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
63 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
64
Tim Peters98791af2001-10-23 01:59:54 +000065- Traceback objects are now scanned by cyclic garbage collection, so
66 cycles created by casual use of sys.exc_info() no longer cause
67 permanent memory leaks (provided garbage collection is enabled).
68
Guido van Rossum49192142001-10-24 20:51:44 +000069- os.extsep -- a new variable needed by the RISCOS support. It is the
70 separator used by extensions, and is '.' on all platforms except
71 RISCOS, where it is '/'. There is no need to use this variable
72 unless you have a masochistic desire to port your code to RISCOS.
73
Tim Peters84362bc2001-10-19 17:55:30 +000074Tools/Demos
75
76Build
77
78C API
79
Tim Peters1fc240e2001-10-26 05:06:50 +000080- New function PySequence_Fast_GET_SIZE() returns the size of a non-
81 NULL result from PySequence_Fast(), more quickly than calling
82 PySequence_Size().
83
Tim Peters84362bc2001-10-19 17:55:30 +000084New platforms
85
Guido van Rossum86443212001-10-27 22:28:54 +000086- We've finally confirmed that this release builds on HP-UX 11.00,
87 *with* threads, and passes the test suite.
88
Tim Peters7a33d8b2001-11-05 02:51:07 +000089- Thanks to a series of patches from Michael Muller, Python may build
90 again under OS/2 Visual Age C++.
91
Guido van Rossum49192142001-10-24 20:51:44 +000092- Updated RISCOS port by Dietmar Schwertberger.
93
Tim Peters84362bc2001-10-19 17:55:30 +000094Tests
95
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000096- Added a test script for the curses module. It isn't run automatically;
97 regrtest.py must be run with '-u curses' to enable it.
98
Tim Peters84362bc2001-10-19 17:55:30 +000099Windows
100
101
Tim Petersabf925f2001-09-28 21:53:42 +0000102What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000103Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000104===========================
105
106Type/class unification and new-style classes
107
Guido van Rossum687ae002001-10-15 22:03:32 +0000108- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000109 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000110 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000111 remains: the __dict__ of a new-style class is a read-only proxy; you
112 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000113 __defined__ attribute of new-style types no longer exists, for lack
114 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000115 future a __cache__ may be resurrected with a similar function, if I
116 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000117
Tim Peters1c9ca872001-10-04 06:43:12 +0000118- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
119 always returned None, even when there was a class docstring).
120
121- doctest now finds and runs docstrings attached to new-style classes,
122 class methods, static methods, and properties.
123
Guido van Rossum9074ef62001-10-16 21:34:49 +0000124Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000125
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000126- A very subtle syntactical pitfall in list comprehensions was fixed.
127 For example: [a+b for a in 'abc', for b in 'def']. The comma in
128 this example is a mistake. Previously, this would silently let 'a'
129 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
130 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
131 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
132 Note that [a for a in <singleton>] is a convoluted way to say
133 [<singleton>] anyway, so it's not like any expressiveness is lost.
134
Guido van Rossum9074ef62001-10-16 21:34:49 +0000135- getattr(obj, name, default) now only catches AttributeError, as
136 documented, rather than returning the default value for all
137 exceptions (which could mask bugs in a __getattr__ hook, for
138 example).
139
Fred Drakecb7a6b52001-10-22 18:41:51 +0000140- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000141 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000142 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000143 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000144
Guido van Rossum1c486092001-10-19 02:05:35 +0000145- unicode(obj) now behaves more like str(obj), accepting arbitrary
146 objects, and calling a __unicode__ method if it exists.
147 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000148 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000149
Barry Warsawf6fb1712001-10-19 05:35:40 +0000150- isinstance() now allows any object as the first argument and a
151 class, a type or something with a __bases__ tuple attribute for the
152 second argument. The second argument may also be a tuple of a
153 class, type, or something with __bases__, in which case isinstance()
154 will return true if the first argument is an instance of any of the
155 things contained in the second argument tuple. E.g.
156
157 isinstance(x, (A, B))
158
159 returns true if x is an instance of A or B.
160
Guido van Rossum9074ef62001-10-16 21:34:49 +0000161Extension modules
162
163- thread.start_new_thread() now returns the thread ID (previously None).
164
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000165- binascii has now two quopri support functions, a2b_qp and b2a_qp.
166
Guido van Rossumc524d952001-10-19 01:31:59 +0000167- readline now supports setting the startup_hook and the
168 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000169
Guido van Rossumc524d952001-10-19 01:31:59 +0000170- os and posix supports chroot(), setgroups() and unsetenv() where
171 available. The stat(), fstat(), statvfs() and fstatvfs() functions
172 now return "pseudo-sequences" -- the various fields can now be
173 accessed as attributes (e.g. os.stat("/").st_mtime) but for
174 backwards compatibility they also behave as a fixed-length sequence.
175 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000176 attributes.
177
178- time: localtime(), gmtime() and strptime() now return a
179 pseudo-sequence similar to the os.stat() return value, with
180 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000181
Guido van Rossum9074ef62001-10-16 21:34:49 +0000182- Decompression objects in the zlib module now accept an optional
183 second parameter to decompress() that specifies the maximum amount
184 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000185
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000186- optional SSL support in the socket module now exports OpenSSL
187 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
188 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000189 automatically seed its PRNG. Also, the keyfile and certfile
190 arguments to socket.ssl() are now optional.
191
192- posixmodule (and by extension, the os module on POSIX platforms) now
193 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000194
Guido van Rossum9074ef62001-10-16 21:34:49 +0000195Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000196
Tim Peters7402f792001-10-02 03:53:41 +0000197- doctest now excludes functions and classes not defined by the module
198 being tested, thanks to Tim Hochberg.
199
Fred Drakecb7a6b52001-10-22 18:41:51 +0000200- HotShot, a new profiler implemented using a C-based callback, has
201 been added. This substantially reduces the overhead of profiling,
202 but it is still quite preliminary. Support modules and
203 documentation will be added in upcoming releases (before 2.2 final).
204
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000205- profile now produces correct output in situations where an exception
206 raised in Python is cleared by C code (e.g. hasattr()). This used
207 to cause wrong output, including spurious claims of recursive
208 functions and attribution of time spent to the wrong function.
209
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000210 The code and documentation for the derived OldProfile and HotProfile
211 profiling classes was removed. The code hasn't worked for years (if
212 you tried to use them, they raised exceptions). OldProfile
213 intended to reproduce the behavior of the profiler Python used more
214 than 7 years ago, and isn't interesting anymore. HotProfile intended
215 to provide a faster profiler (but producing less information), and
216 that's a worthy goal we intend to meet via a different approach (but
217 without losing information).
218
Tim Peterscce092d2001-10-09 05:31:56 +0000219- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000220 a much better system-specific calibration constant. The constant can
221 now be specified in an instance constructor, or as a Profile class or
222 instance variable, instead of by editing profile.py's source code.
223 Calibration must still be done manually (see the docs for the profile
224 module).
225
226 Note that Profile.calibrate() must be overriden by subclasses.
227 Improving the accuracy required exploiting detailed knowledge of
228 profiler internals; the earlier method abstracted away the details
229 and measured a simplified model instead, but consequently computed
230 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000231
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000232- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000233 which indicates whether output is intended for the header 'Q'
234 encoding.
235
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000236- The SocketServer.ThreadingMixIn class now closes the request after
237 finish_request() returns. (Not when it errors out though.)
238
Barry Warsawf6fb1712001-10-19 05:35:40 +0000239- The nntplib module's NNTP.body() method has grown a `file' argument
240 to allow saving the message body to a file.
241
242- The email package has added a class email.Parser.HeaderParser which
243 only parses headers and does not recurse into the message's body.
244 Also, the module/class MIMEAudio has been added for representing
245 audio data (contributed by Anthony Baxter).
246
247- ftplib should be able to handle files > 2GB.
248
249- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
250 ON, and OFF.
251
Fred Drakecb7a6b52001-10-22 18:41:51 +0000252- xml.dom.minidom NodeList objects now support the length attribute
253 and item() method as required by the DOM specifications.
254
Guido van Rossumed554f62001-10-02 23:15:37 +0000255Tools/Demos
256
257- Demo/dns was removed. It no longer serves any purpose; a package
258 derived from it is now maintained by Anthony Baxter, see
259 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000260
Barry Warsawf6fb1712001-10-19 05:35:40 +0000261- The freeze tool has been made more robust, and two new options have
262 been added: -X and -E.
263
Tim Petersabf925f2001-09-28 21:53:42 +0000264Build
265
Barry Warsawf6fb1712001-10-19 05:35:40 +0000266- configure will use CXX in LINKCC if CXX is used to build main() and
267 the system requires to link a C++ main using the C++ compiler.
268
Tim Petersabf925f2001-09-28 21:53:42 +0000269C API
270
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000271- The documentation for the tp_compare slot is updated to require that
272 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
273 not correct. This is not yet enforced but will be enforced in
274 Python 2.3; even later, we may use -2 to indicate errors and +2 for
275 "NotImplemented". Right now, -1 should be used for an error return.
276
Tim Petersd38b1c72001-09-30 05:09:37 +0000277- PyLong_AsLongLong() now accepts int (as well as long) arguments.
278 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
279 as long) arguments.
280
Guido van Rossum3c288632001-10-16 21:13:49 +0000281- PyThread_start_new_thread() now returns a long int giving the thread
282 ID, if one can be calculated; it returns -1 for error, 0 if no
283 thread ID is calculated (this is an incompatible change, but only
284 the thread module used this API). This code has only really been
285 tested on Linux and Windows; other platforms please beware (and
286 report any bugs or strange behavior).
287
Guido van Rossum1c486092001-10-19 02:05:35 +0000288- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
289 input.
290
Tim Petersabf925f2001-09-28 21:53:42 +0000291New platforms
292
293Tests
294
295Windows
296
Tim Peters04cf1d32001-10-09 22:39:40 +0000297- Installer: If you install IDLE, and don't disable file-extension
298 registration, a new "Edit with IDLE" context (right-click) menu entry
299 is created for .py and .pyw files.
300
Tim Peters1ce3cf72001-10-01 17:58:40 +0000301- The signal module now supports SIGBREAK on Windows, thanks to Steven
302 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
303 action remains to call Win32 ExitProcess(). This can be changed via
304 signal.signal(). For example:
305
306 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
307 # (SIGINT) behavior.
308 import signal
309 signal.signal(signal.SIGBREAK,
310 signal.default_int_handler)
311
312 try:
313 while 1:
314 pass
315 except KeyboardInterrupt:
316 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
317 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
318 # program without the possibility for any Python-level cleanup).
319 print "Clean exit"
320
Tim Petersabf925f2001-09-28 21:53:42 +0000321
Tim Petersb07352e2001-09-08 01:25:47 +0000322What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000323Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000324===========================
325
Guido van Rossum808eea72001-09-25 04:15:41 +0000326Type/class unification and new-style classes
327
328- pydoc and inspect are now aware of new-style classes;
329 e.g. help(list) at the interactive prompt now shows proper
330 documentation for all operations on list objects.
331
332- Applications using Jim Fulton's ExtensionClass module can now safely
333 be used with Python 2.2. In particular, Zope 2.4.1 now works with
334 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
335 examples also work again. It is hoped that Gtk and Boost also work
336 with 2.2a4 and beyond. (If you can confirm this, please write
337 webmaster@python.org; if there are still problems, please open a bug
338 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000339
Tim Peters66c1a522001-09-24 21:17:50 +0000340- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
341 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
342 in the constructed property object. fget, fset and fdel weren't
343 discoverable from Python in 2.2a3. __doc__ is new, and allows to
344 associate a docstring with a property.
345
Guido van Rossum808eea72001-09-25 04:15:41 +0000346- Comparison overloading is now more completely implemented. For
347 example, a str subclass instance can properly be compared to a str
348 instance, and it can properly overload comparison. Ditto for most
349 other built-in object types.
350
351- The repr() of new-style classes has changed; instead of <type
352 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
353 *except* for built-in types, which are still rendered as <type
354 'Foo'> (to avoid upsetting existing code that might parse or
355 otherwise rely on repr() of certain type objects).
356
357- The repr() of new-style objects is now always <Foo object at XXX>;
358 previously, it was sometimes <Foo instance at XXX>.
359
360- For new-style classes, what was previously called __getattr__ is now
361 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000362 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000363 one in classic classes is defined which is called only if regular
364 attribute access raises AttributeError; to catch *all* attribute
365 access, you can use __getattribute__ (for new-style classes). If
366 both are defined, __getattribute__ is called first, and if it raises
367 AttributeError, __getattr__ is called.
368
369- The __class__ attribute of new-style objects can be assigned to.
370 The new class must have the same C-level object layout as the old
371 class.
372
373- The builtin file type can be subclassed now. In the usual pattern,
374 "file" is the name of the builtin type, and file() is a new builtin
375 constructor, with the same signature as the builtin open() function.
376 file() is now the preferred way to open a file.
377
378- Previously, __new__ would only see sequential arguments passed to
379 the type in a constructor call; __init__ would see both sequential
380 and keyword arguments. This made no sense whatsoever any more, so
381 now both __new__ and __init__ see all arguments.
382
383- Previously, hash() applied to an instance of a subclass of str or
384 unicode always returned 0. This has been repaired.
385
386- Previously, an operation on an instance of a subclass of an
387 immutable type (int, long, float, complex, tuple, str, unicode),
388 where the subtype didn't override the operation (and so the
389 operation was handled by the builtin type), could return that
390 instance instead a value of the base type. For example, if s was of
391 a str sublass type, s[:] returned s as-is. Now it returns a str
392 with the same value as s.
393
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000394- Provisional support for pickling new-style objects has been added.
395
Guido van Rossum808eea72001-09-25 04:15:41 +0000396Core
397
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000398- file.writelines() now accepts any iterable object producing strings.
399
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000400- PyUnicode_FromEncodedObject() now works very much like
401 PyObject_Str(obj) in that it tries to use __str__/tp_str
402 on the object if the object is not a string or buffer. This
403 makes unicode() behave like str() when applied to non-string/buffer
404 objects.
405
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000406- PyFile_WriteObject now passes Unicode objects to the file's write
407 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000408 of a print statement must support Unicode objects, i.e. they must
409 at least convert them into ASCII strings.
410
Guido van Rossum624c8af2001-09-18 15:21:04 +0000411- Thread scheduling on Solaris should be improved; it is no longer
412 necessary to insert a small sleep at the start of a thread in order
413 to let other runnable threads be scheduled.
414
Tim Petersb07352e2001-09-08 01:25:47 +0000415Library
416
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000417- StringIO.StringIO instances and cStringIO.StringIO instances support
418 read character buffer compatible objects for their .write() methods.
419 These objects are converted to strings and then handled as such
420 by the instances.
421
Barry Warsaw2f600732001-09-24 04:28:10 +0000422- The "email" package has been added. This is basically a port of the
423 mimelib package <http://sf.net/projects/mimelib> with API changes
424 and some implementations updated to use iterators and generators.
425
Tim Peters8a9c2842001-09-22 21:30:22 +0000426- difflib.ndiff() and difflib.Differ.compare() are generators now. This
427 restores the ability of Tools/scripts/ndiff.py to start producing output
428 before the entire comparison is complete.
429
Barry Warsaw58b072d2001-09-22 04:44:21 +0000430- StringIO.StringIO instances and cStringIO.StringIO instances support
431 iteration just like file objects (i.e. their .readline() method is
432 called for each iteration until it returns an empty string).
433
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000434- The codecs module has grown four new helper APIs to access
435 builtin codecs: getencoder(), getdecoder(), getreader(),
436 getwriter().
437
Guido van Rossum624c8af2001-09-18 15:21:04 +0000438- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
439 simplifies writing XML RPC servers.
440
Barry Warsaw647d5e82001-09-28 17:01:02 +0000441- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000442 after interpretation of symbolic links. On non-Unix systems, this
443 is an alias for os.path.abspath().
444
Tim Peters16a77ad2001-09-08 04:00:12 +0000445- operator.indexOf() (PySequence_Index() in the C API) now works with any
446 iterable object.
447
Guido van Rossum624c8af2001-09-18 15:21:04 +0000448- smtplib now supports various authentication and security features of
449 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000450
Guido van Rossum624c8af2001-09-18 15:21:04 +0000451- hmac: a new module implementing keyed hashing for message
452 authentication.
453
454- mimetypes now recognizes more extensions and file types. At the
455 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000456
Guido van Rossum624c8af2001-09-18 15:21:04 +0000457- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000458 Python 2.2 bytecode generation. It has also been promoted from a
459 Tool to a standard library package. (Tools/compiler still exists as
460 a sample driver.)
461
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000462Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000463
Tim Petersb07352e2001-09-08 01:25:47 +0000464Build
465
Guido van Rossum624c8af2001-09-18 15:21:04 +0000466- Large file support (LFS) is now automatic when the platform supports
467 it; no more manual configuration tweaks are needed. On Linux, at
468 least, it's possible to have a system whose C library supports large
469 files but whose kernel doesn't; in this case, large file support is
470 still enabled but doesn't do you any good unless you upgrade your
471 kernel or share your Python executable with another system whose
472 kernel has large file support.
473
474- The configure script now supplies plausible defaults in a
475 cross-compilation environment. This doesn't mean that the supplied
476 values are always correct, or that cross-compilation now works
477 flawlessly -- but it's a first step (and it shuts up most of
478 autoconf's warnings about AC_TRY_RUN).
479
480- The Unix build is now a bit less chatty, courtesy of the parser
481 generator. The build is completely silent (except for errors) when
482 using "make -s", thanks to a -q option to setup.py.
483
Tim Petersb07352e2001-09-08 01:25:47 +0000484C API
485
Guido van Rossum624c8af2001-09-18 15:21:04 +0000486- The "structmember" API now supports some new flag bits to deny read
487 and/or write access to attributes in restricted execution mode.
488
Tim Petersb07352e2001-09-08 01:25:47 +0000489New platforms
490
Guido van Rossum624c8af2001-09-18 15:21:04 +0000491- Compaq's iPAQ handheld, running the "familiar" Linux distribution
492 (http://familiar.handhelds.org).
493
Tim Petersb07352e2001-09-08 01:25:47 +0000494Tests
495
Tim Peters8a9c2842001-09-22 21:30:22 +0000496- The "classic" standard tests, which work by comparing stdout to
497 an expected-output file under Lib/test/output/, no longer stop at
498 the first mismatch. Instead the test is run to completion, and a
499 variant of ndiff-style comparison is used to report all differences.
500 This is much easier to understand than the previous style of reporting.
501
502- The unittest-based standard tests now use regrtest's test_main()
503 convention, instead of running as a side-effect of merely being
504 imported. This allows these tests to be run in more natural and
505 flexible ways as unittests, outside the regrtest framework.
506
507- regrtest.py is much better integrated with unittest and doctest now,
508 especially in regard to reporting errors.
509
Tim Petersb07352e2001-09-08 01:25:47 +0000510Windows
511
Guido van Rossum624c8af2001-09-18 15:21:04 +0000512- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000513 that support it (NTFS under Windows 2000). See "What's New in
514 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000515
Tim Petersb07352e2001-09-08 01:25:47 +0000516
Tim Petersedc99312001-08-22 21:36:50 +0000517What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000518Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000519===========================
520
521Core
522
Tim Peters9fffa3e2001-09-04 05:14:19 +0000523- Conversion of long to float now raises OverflowError if the long is too
524 big to represent as a C double.
525
Tim Peters32f453e2001-09-03 08:35:41 +0000526- The 3-argument builtin pow() no longer allows a third non-None argument
527 if either of the first two arguments is a float, or if both are of
528 integer types and the second argument is negative (in which latter case
529 the arguments are converted to float, so this is really the same
530 restriction).
531
Tim Peters5d2b77c2001-09-03 05:47:38 +0000532- The builtin dir() now returns more information, and sometimes much
533 more, generally naming all attributes of an object, and all attributes
534 reachable from the object via its class, and from its class's base
535 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
536 an empty list. In 2.2a3,
537
538 >>> dir([])
539 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
540 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
541 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
542 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
543 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
544 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
545 'reverse', 'sort']
546
547 dir(module) continues to return only the module's attributes, though.
548
Tim Petersbdee63f2001-09-02 03:40:59 +0000549- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000550 than raising OverflowError. This is a partial implementation of PEP
551 237. You can use -Wdefault::OverflowWarning to enable a warning for
552 this situation, and -Werror::OverflowWarning to revert to the old
553 OverflowError exception.
554
Guido van Rossum61c345f2001-09-04 03:26:15 +0000555- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000556 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000557 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
558 -Qold, meaning the / operator has its classic meaning and no
559 warnings are issued. Using -Qwarn issues a run-time warning about
560 all uses of classic division for int and long arguments; -Qwarnall
561 also warns about classic division for float and complex arguments
562 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
563 new division by default, but only in the __main__ module. You can
564 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
565 __main__ module new division, and warns about classic division
566 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000567
Tim Petersbdee63f2001-09-02 03:40:59 +0000568- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000569 long, float, str, unicode, and tuple. (The types complex, list and
570 dictionary can also be subclassed; this was introduced earlier.)
571 Note that restrictions apply when subclassing immutable built-in
572 types: you can only affect the value of the instance by overloading
573 __new__. You can add mutable attributes, and the subclass instances
574 will have a __dict__ attribute, but you cannot change the "value"
575 (as implemented by the base class) of an immutable subclass instance
576 once it is created.
577
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000578- The dictionary constructor now takes an optional argument, a
579 mapping-like object, and initializes the dictionary from its
580 (key, value) pairs.
581
Tim Petersbdee63f2001-09-02 03:40:59 +0000582- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000583 "cooperative super calls" in a multiple inheritance setting. For an
584 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
585
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000586- A new built-in type, property, has been added. This enables the
587 creation of "properties". These are attributes implemented by
588 getter and setter functions (or only one of these for read-only or
589 write-only attributes), without the need to override __getattr__.
590 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000591
Tim Petersbdee63f2001-09-02 03:40:59 +0000592- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000593 liberalized, to allow leading zeroes. Examples of literals now
594 legal that were SyntaxErrors before:
595
596 00.0 0e3 0100j 07.5 00000000000000000008.
597
Tim Petersbdee63f2001-09-02 03:40:59 +0000598- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000599 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
600
Tim Petersedc99312001-08-22 21:36:50 +0000601Library
602
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000603- telnetlib includes symbolic names for the options, and support for
604 setting an option negotiation callback.
605
Tim Petersa40c7932001-09-05 22:36:56 +0000606- The new C standard no longer requires that math libraries set errno to
607 ERANGE on overflow. For platform libraries that exploit this new
608 freedom, Python's overflow-checking was wholly broken. A new overflow-
609 checking scheme attempts to repair that, but may not be reliable on all
610 platforms (C doesn't seem to provide anything both useful and portable
611 in this area anymore).
612
Martin v. Löwis44f86962001-09-05 13:44:54 +0000613- Asynchronous timeout actions are available through the new class
614 threading.Timer.
615
Tim Peters78526162001-09-05 00:53:45 +0000616- math.log and math.log10 now return sensible results for even huge
617 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
618
Tim Petersbdee63f2001-09-02 03:40:59 +0000619- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000620 currently held. See the docs for the imp module.
621
Tim Petersbdee63f2001-09-02 03:40:59 +0000622- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000623 dumps containing ints written on platforms where Python ints are 8 bytes.
624 When read on a box where Python ints are 4 bytes, such values are
625 converted to Python longs.
626
Tim Petersbdee63f2001-09-02 03:40:59 +0000627- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000628 code objects is no longer allowed. This plugs a security hole.
629
Steve Purcell6091cd62001-09-06 16:05:17 +0000630- unittest.TestResult instances no longer store references to tracebacks
631 generated by test failures. This prevents unexpected dangling references
632 to objects that should be garbage collected between tests.
633
Tim Petersedc99312001-08-22 21:36:50 +0000634Tools
635
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000636- Tools/scripts/fixdiv.py has been added which can be used to fix
637 division operators as per PEP 238.
638
Tim Petersedc99312001-08-22 21:36:50 +0000639Build
640
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000641- If you are an adventurous person using Mac OS X you may want to look at
642 Mac/OSX. There is a Makefile there that will build Python as a real Mac
643 application, which can be used for experimenting with Carbon or Cocoa.
644 Discussion of this on pythonmac-sig, please.
645
Tim Peters7eea37e2001-09-04 22:08:56 +0000646C API
647
648- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000649
Tim Peters9fffa3e2001-09-04 05:14:19 +0000650- Note that PyLong_AsDouble can fail! This has always been true, but no
651 callers checked for it. It's more likely to fail now, because overflow
652 errors are properly detected now. The proper way to check:
653
654 double x = PyLong_AsDouble(some_long_object);
655 if (x == -1.0 && PyErr_Occurred()) {
656 /* The conversion failed. */
657 }
658
Tim Petersbdee63f2001-09-02 03:40:59 +0000659- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000660 compile but will not participate in GC. To upgrade an extension
661 module:
662
663 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000664
Neil Schemenauer4042c692001-08-30 15:38:01 +0000665 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
666 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000667
Neil Schemenauer4042c692001-08-30 15:38:01 +0000668 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
669 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000670
Neil Schemenauer4042c692001-08-30 15:38:01 +0000671 - remove PyGC_HEAD_SIZE from object size calculations
672
673 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
674
Tim Petersbdee63f2001-09-02 03:40:59 +0000675- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000676 These can be used safely to construct string objects from a
677 sprintf-style format string (similar to the format string supported
678 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000679
Tim Petersedc99312001-08-22 21:36:50 +0000680New platforms
681
Tim Petersb7da0902001-09-02 23:01:43 +0000682- Stephen Hansen contributed patches sufficient to get a clean compile
683 under Borland C (Windows), but he reports problems running it and ran
684 out of time to complete the port. Volunteers? Expect a MemoryError
685 when importing the types module; this is probably shallow, and
686 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000687
Tim Petersedc99312001-08-22 21:36:50 +0000688Tests
689
690Windows
691
Tim Peters6e13a562001-09-06 00:32:15 +0000692- Large file support is now enabled on Win32 platforms as well as on
693 Win64. This means that, for example, you can use f.tell() and f.seek()
694 to manipulate files larger than 2 gigabytes (provided you have enough
695 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000696 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
697 filesize limit, and large file support makes no difference there.
698 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
699 NTFS has no practical limit on file size, and files of any size can be
700 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000701
Tim Petersbdee63f2001-09-02 03:40:59 +0000702- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000703 points to command.com (patch from Brian Quinlan).
704
Tim Petersedc99312001-08-22 21:36:50 +0000705
Tim Peters20f51a72001-07-21 02:31:40 +0000706What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000707Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000708===========================
709
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000710Build
711
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000712- Tim Peters developed a brand new Windows installer using Wise 8.1,
713 generously donated to us by Wise Solutions.
714
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000715- configure supports a new option --enable-unicode, with the values
716 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
717 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000718
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000719- A new configure option --enable-framework builds a Mac OS X framework,
720 which "make frameworkinstall" will install. This provides a starting
721 point for more mac-like functionality, join pythonmac-sig@python.org
722 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000723
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000724- The NeXT platform is no longer supported.
725
726- The `new' module is now statically linked.
727
Tim Peters0afb6092001-08-15 06:06:44 +0000728Tools
729
730- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000731 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000732 the module docstring for details.
733
Tim Peters20f51a72001-07-21 02:31:40 +0000734Tests
735
Tim Peters5e824c32001-08-12 22:25:01 +0000736- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000737 platforms, allowing to give clearer test result output. regrtest
738 also has optional --use/-u switch to run normally disabled tests
739 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000740
Tim Peters20f51a72001-07-21 02:31:40 +0000741- Several new tests in the standard test suite, with special thanks to
742 Nick Mathewson.
743
744Core
745
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000746- The floor division operator // has been added as outlined in PEP
747 238. The / operator still provides classic division (and will until
748 Python 3.0) unless "from __future__ import division" is included, in
749 which case the / operator will provide true division. The operator
750 module provides truediv() and floordiv() functions. Augmented
751 assignment variants are included, as are the equivalent overloadable
752 methods and C API methods. See the PEP for a full discussion:
753 <http://python.sf.net/peps/pep-0238.html>
754
Tim Peters6cd6a822001-08-17 22:11:27 +0000755- Future statements are now effective in simulated interactive shells
756 (like IDLE). This should "just work" by magic, but read Michael
757 Hudson's "Future statements in simulated shells" PEP 264 for full
758 details: <http://python.sf.net/peps/pep-0264.html>.
759
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000760- The type/class unification (PEP 252-253) was integrated into the
761 trunk and is not so tentative any more (the exact specification of
762 some features is still tentative). A lot of work has done on fixing
763 bugs and adding robustness and features (performance still has to
764 come a long way).
765
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000766- Warnings about a mismatch in the Python API during extension import
767 now use the Python warning framework (which makes it possible to
768 write filters for these warnings).
769
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000770- A function's __dict__ (aka func_dict) will now always be a
771 dictionary. It used to be possible to delete it or set it to None,
772 but now both actions raise TypeErrors. It is still legal to set it
773 to a dictionary object. Getting func.__dict__ before any attributes
774 have been assigned now returns an empty dictionary instead of None.
775
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000776- A new command line option, -E, was added which disables the use of
777 all environment variables, or at least those that are specifically
778 significant to Python. Usually those have a name starting with
779 "PYTHON". This was used to fix a problem where the tests fail if
780 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
781 older distribution.
782
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000783Library
784
Tim Peters5e824c32001-08-12 22:25:01 +0000785- New class Differ and new functions ndiff() and restore() in difflib.py.
786 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000787 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000788
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000789- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
790 value using the minimal quoting required for the value; more
791 reliable than using xml.sax.saxutils.escape() for attribute values.
792
793- Readline completion support for cmd.Cmd was added.
794
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000795- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
796
797- Added function threading.BoundedSemaphore()
798
799- Added Ka-Ping Yee's cgitb.py module.
800
801- The `new' module now exposes the CO_xxx flags.
802
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000803New platforms
804
805C API
806
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000807- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
808 which provide a cross-platform implementations for the
809 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
810 the standard sprintf() and vsprintf() C lib APIs, these versions
811 apply bounds checking on the used buffer which enhances protection
812 against buffer overruns.
813
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000814- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000815 and extensions using different Unicode widths is rendered next to
816 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000817 will result in an ImportError. Unicode extensions writers must make
818 sure to check the Unicode width compatibility in their extensions by
819 using at least one of the mangled Unicode APIs in the extension.
820
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000821- Two new flags METH_NOARGS and METH_O are available in method definition
822 tables to simplify implementation of methods with no arguments and a
823 single untyped argument. Calling such methods is more efficient than
824 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
825 deprecated.
826
Tim Petersc1731372001-08-04 08:12:36 +0000827Windows
828
829- "import module" now compiles module.pyw if it exists and nothing else
830 relevant is found.
831
Tim Peters20f51a72001-07-21 02:31:40 +0000832
Guido van Rossum55a78992001-07-17 17:22:32 +0000833What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +0000834Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +0000835===========================
836
837Core
Tim Petersa814db52001-05-14 07:05:58 +0000838
Tim Peters6d6c1a32001-08-02 04:15:00 +0000839- TENTATIVELY, a large amount of code implementing much of what's
840 described in PEP 252 (Making Types Look More Like Classes) and PEP
841 253 (Subtyping Built-in Types) was added. This will be released
842 with Python 2.2a1. Documentation will be provided separately
843 through http://www.python.org/2.2/. The purpose of releasing this
844 with Python 2.2a1 is to test backwards compatibility. It is
845 possible, though not likely, that a decision is made not to release
846 this code as part of 2.2 final, if any serious backwards
847 incompapatibilities are found during alpha testing that cannot be
848 repaired.
849
Guido van Rossum55a78992001-07-17 17:22:32 +0000850- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000851 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000852 more 'yield' statements. See PEP 255. Since this adds a new
853 keyword to the language, this feature must be enabled by including a
854 future statement: "from __future__ import generators" (see PEP 236).
855 Generators will become a standard feature in a future release
856 (probably 2.3). Without this future statement, 'yield' remains an
857 ordinary identifier, but a warning is issued each time it is used.
858 (These warnings currently don't conform to the warnings framework of
859 PEP 230; we intend to fix this in 2.2a2.)
860
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000861- The UTF-16 codec was modified to be more RFC compliant. It will now
862 only remove BOM characters at the start of the string and then
863 only if running in native mode (UTF-16-LE and -BE won't remove a
864 leading BMO character).
865
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000866- Strings now have a new method .decode() to complement the already
867 existing .encode() method. These two methods provide direct access
868 to the corresponding decoders and encoders of the registered codecs.
869
870 To enhance the usability of the .encode() method, the special
871 casing of Unicode object return values was dropped (Unicode objects
872 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000873
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000874 Both methods will now return whatever the codec in charge of the
875 requested encoding returns as object, e.g. Unicode codecs will
876 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
877 will return u"äöü"). This enables codec writer to create codecs
878 for various simple to use conversions.
879
880 New codecs were added to demonstrate these new features (the .encode()
881 and .decode() columns indicate the type of the returned objects):
882
883 Name | .encode() | .decode() | Description
884 ----------------------------------------------------------------------
885 uu | string | string | UU codec (e.g. for email)
886 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000887 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000888 zlib | string | string | zlib compression
889 hex | string | string | 2-byte hex codec
890 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
891
Mark Hammond2a0af792001-05-14 03:09:36 +0000892- Some operating systems now support the concept of a default Unicode
893 encoding for file system operations. Notably, Windows supports 'mbcs'
894 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000895 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000896 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000897
898 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000899 functions that return filenames (such as os.listdir()) to return Python
900 string objects pre-encoded using the default file system encoding for
901 the platform. As this encoding is likely to be different from Python's
902 default encoding, converting this name to a Unicode object before passing
903 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000904 would attempt to use its default encoding (generally ASCII) rather than
905 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000906
Tim Petersa814db52001-05-14 07:05:58 +0000907 In general, this change simply removes surprises when working with
908 Unicode and the file system, making these operations work as you expect,
909 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000910 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000911
Tim Peters61dff2b2001-05-08 15:43:37 +0000912- Float (and complex) literals in source code were evaluated to full
913 precision only when running from a .py file; the same code loaded from a
914 .pyc (or .pyo) file could suffer numeric differences starting at about the
915 12th significant decimal digit. For example, on a machine with IEEE-754
916 floating arithmetic,
917
918 x = 9007199254740992.0
919 print long(x)
920
921 printed 9007199254740992 if run directly from .py, but 9007199254740000
922 if from a compiled (.pyc or .pyo) file. This was due to marshal using
923 str(float) instead of repr(float) when building code objects. marshal
924 now uses repr(float) instead, which should reproduce floats to full
925 machine precision (assuming the platform C float<->string I/O conversion
926 functions are of good quality).
927
928 This may cause floating-point results to change in some cases, and
929 usually for the better, but may also cause numerically unstable
930 algorithms to break.
931
Tim Peters2f228e72001-05-13 00:19:31 +0000932- The implementation of dicts suffers fewer collisions, which has speed
933 benefits. However, the order in which dict entries appear in dict.keys(),
934 dict.values() and dict.items() may differ from previous releases for a
935 given dict. Nothing is defined about this order, so no program should
936 rely on it. Nevertheless, it's easy to write test cases that rely on the
937 order by accident, typically because of printing the str() or repr() of a
938 dict to an "expected results" file. See Lib/test/test_support.py's new
939 sortdict(dict) function for a simple way to display a dict in sorted
940 order.
941
Tim Peters7a3bfc32001-06-12 01:22:22 +0000942- Many other small changes to dicts were made, resulting in faster
943 operation along the most common code paths.
944
Guido van Rossum10315822001-05-01 20:54:30 +0000945- Dictionary objects now support the "in" operator: "x in dict" means
946 the same as dict.has_key(x).
947
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000948- The update() method of dictionaries now accepts generic mapping
949 objects. Specifically the argument object must support the .keys()
950 and __getitem__() methods. This allows you to say, for example,
951 {}.update(UserDict())
952
Guido van Rossum10315822001-05-01 20:54:30 +0000953- Iterators were added; this is a generalized way of providing values
954 to a for loop. See PEP 234. There's a new built-in function iter()
955 to return an iterator. There's a new protocol to get the next value
956 from an iterator using the next() method (in Python) or the
957 tp_iternext slot (in C). There's a new protocol to get iterators
958 using the __iter__() method (in Python) or the tp_iter slot (in C).
959 Iterating (i.e. a for loop) over a dictionary generates its keys.
960 Iterating over a file generates its lines.
961
Tim Petersf553f892001-05-01 20:45:31 +0000962- The following functions were generalized to work nicely with iterator
963 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000964 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000965 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
966 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000967 join() method of strings
968 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000969 'x in y' and 'x not in y' (PySequence_Contains() in C API)
970 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000971 right-hand side of assignment statements with multiple targets, such as
972 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000973
Tim Petersd85e1022001-05-11 21:51:48 +0000974- Accessing module attributes is significantly faster (for example,
975 random.random or os.path or yourPythonModule.yourAttribute).
976
Tim Peterse63415e2001-05-08 04:38:29 +0000977- Comparing dictionary objects via == and != is faster, and now works even
978 if the keys and values don't support comparisons other than ==.
979
Tim Peters95bf9392001-05-10 08:32:44 +0000980- Comparing dictionaries in ways other than == and != is slower: there were
981 insecurities in the dict comparison implementation that could cause Python
982 to crash if the element comparison routines for the dict keys and/or
983 values mutated the dicts. Making the code bulletproof slowed it down.
984
Tim Peterseb28ef22001-06-02 05:27:19 +0000985- Collisions in dicts are resolved via a new approach, which can help
986 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000987 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000988 faster now. Thanks to Christian Tismer for pointing out the cause and
989 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000990
Tim Peters52e155e2001-06-16 05:42:57 +0000991- repr() is much faster for large containers (dict, list, tuple).
992
993
Tim Petersa814db52001-05-14 07:05:58 +0000994Library
995
Fred Drake960fdf92001-07-20 18:38:26 +0000996- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
997 were added to the string module. These a locale-indenpendent
998 constants, unlike letters, lowercase, and uppercase. These are now
999 use in appropriate locations in the standard library.
1000
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001001- The flags used in dlopen calls can now be configured using
1002 sys.setdlopenflags and queried using sys.getdlopenflags.
1003
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001004- Fredrik Lundh's xmlrpclib is now a standard library module. This
1005 provides full client-side XML-RPC support. In addition,
1006 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1007 one asyncore-based). Thanks to Eric Raymond for the documentation.
1008
Guido van Rossum643d3912001-07-05 14:46:25 +00001009- The xrange() object is simplified: it no longer supports slicing,
1010 repetition, comparisons, efficient 'in' checking, the tolist()
1011 method, or the start, stop and step attributes. See PEP 260.
1012
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001013- A new function fnmatch.filter to filter lists of file names was added.
1014
Barry Warsawffd674d2001-05-22 16:00:10 +00001015- calendar.py uses month and day names based on the current locale.
1016
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001017- strop is now *really* obsolete (this was announced before with 1.6),
1018 and issues DeprecationWarning when used (except for the four items
1019 that are still imported into string.py).
1020
Tim Petersa814db52001-05-14 07:05:58 +00001021- Cookie.py now sorts key+value pairs by key in output strings.
1022
1023- pprint.isrecursive(object) didn't correctly identify recursive objects.
1024 Now it does.
1025
Tim Peters95b3f782001-05-14 18:39:41 +00001026- pprint functions now much faster for large containers (tuple, list, dict).
1027
Tim Peters7b9542a2001-06-10 23:40:19 +00001028- New 'q' and 'Q' format codes in the struct module, corresponding to C
1029 types "long long" and "unsigned long long" (on Windows, __int64). In
1030 native mode, these can be used only when the platform C compiler supports
1031 these types (when HAVE_LONG_LONG is #define'd by the Python config
1032 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001033 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1034 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001035
Guido van Rossum83213cc2001-06-12 16:48:52 +00001036- The site module installs a new built-in function 'help' that invokes
1037 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1038 it displays a message reminding the user to use 'help()' or
1039 'help(object)'.
1040
Tim Petersa814db52001-05-14 07:05:58 +00001041Tests
1042
1043- New test_mutants.py runs dict comparisons where the key and value
1044 comparison operators mutute the dicts randomly during comparison. This
1045 rapidly causes Python to crash under earlier releases (not for the faint
1046 of heart: it can also cause Win9x to freeze or reboot!).
1047
1048- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001049 pprint.isreadable() return sensible results. Also verifies that simple
1050 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001051
Tim Peters4324aa32001-05-28 22:30:08 +00001052C API
1053
1054- Removed the unused last_is_sticky argument from the internal
1055 _PyTuple_Resize(). If this affects you, you were cheating.
1056
1057
Guido van Rossum55a78992001-07-17 17:22:32 +00001058======================================================================
1059
1060
Guido van Rossumffe13be2001-04-16 18:46:45 +00001061What's New in Python 2.1 (final)?
1062=================================
1063
1064We only changed a few things since the last release candidate, all in
1065Python library code:
1066
1067- A bug in the locale module was fixed that affected locales which
1068 define no grouping for numeric formatting.
1069
1070- A few bugs in the weakref module's implementations of weak
1071 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1072 and the test suite was updated to check for these bugs.
1073
1074- An old bug in the os.path.walk() function (introduced in Python
1075 2.0!) was fixed: a non-existent file would cause an exception
1076 instead of being ignored.
1077
1078- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1079 PyChecker.
1080
1081
Guido van Rossum5b08f132001-04-16 02:05:23 +00001082What's New in Python 2.1c2?
1083===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001084
Guido van Rossum5b08f132001-04-16 02:05:23 +00001085A flurry of small changes, and one showstopper fixed in the nick of
1086time made it necessary to release another release candidate. The list
1087here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001088
Guido van Rossum5b08f132001-04-16 02:05:23 +00001089Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001090
Guido van Rossum5b08f132001-04-16 02:05:23 +00001091- Tim discovered a nasty bug in the dictionary code, caused by
1092 PyDict_Next() calling dict_resize(), and the GC code's use of
1093 PyDict_Next() violating an assumption in dict_items(). This was
1094 fixed with considerable amounts of band-aid, but the net effect is a
1095 saner and more robust implementation.
1096
1097- Made a bunch of symbols static that were accidentally global.
1098
1099Build and Ports
1100
1101- The setup.py script didn't check for a new enough version of zlib
1102 (1.1.3 is needed). Now it does.
1103
1104- Changed "make clean" target to also remove shared libraries.
1105
1106- Added a more general warning about the SGI Irix optimizer to README.
1107
1108Library
1109
1110- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1111 omitted the slash between host and file.html.
1112
1113- The mailbox module's _Mailbox class contained a completely broken
1114 and undocumented seek() method. Ripped it out.
1115
1116- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1117 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1118
1119- Fixed a few last-minute bugs in unittest.
1120
1121Extensions
1122
1123- Reverted the patch to the OpenSSL code in socketmodule.c to support
1124 RAND_status() and the EGD, and the subsequent patch that tried to
1125 fix it for pre-0.9.5 versions; the problem with the patch is that on
1126 some systems it issues a warning whenever socket is imported, and
1127 that's unacceptable.
1128
1129Tests
1130
1131- Fixed the pickle tests to work with "import test.test_pickle".
1132
1133- Tweaked test_locale.py to actually run the test Windows.
1134
1135- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1136 not "wb" (which is not a valid mode at all).
1137
1138- Fix pstats browser crashes. Import readline if it exists to make
1139 the user interface nicer.
1140
1141- Add "import thread" to the top of test modules that import the
1142 threading module (test_asynchat and test_threadedtempfile). This
1143 prevents test failures caused by a broken threading module resulting
1144 from a previously caught failed import.
1145
1146- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1147 needed on some platforms (e.g. Solaris 8) when the tests are run
1148 twice in succession.
1149
1150- Skip rather than fail test_sunaudiodev if no audio device is found.
1151
1152
1153What's New in Python 2.1c1?
1154===========================
1155
1156This list was significantly updated when 2.1c2 was released; the 2.1c1
1157release didn't mention most changes that were actually part of 2.1c1:
1158
1159Legal
1160
1161- Copyright was assigned to the Python Software Foundation (PSF) and a
1162 PSF license (very similar to the CNRI license) was added.
1163
1164- The CNRI copyright notice was updated to include 2001.
1165
1166Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001167
Guido van Rossumc9932722001-04-12 02:31:27 +00001168- After a public outcry, assignment to __debug__ is no longer illegal;
1169 instead, a warning is issued. It will become illegal in 2.2.
1170
Guido van Rossum5b08f132001-04-16 02:05:23 +00001171- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1172 "%#x" now always prepends "0x", even if the value is zero.
1173
1174- Fixed some nits in the bytecode compiler.
1175
1176- Fixed core dumps when calling certain kinds of non-functions.
1177
1178- Fixed various core dumps caused by reference count bugs.
1179
1180Build and Ports
1181
1182- Use INSTALL_SCRIPT to install script files.
1183
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001184- New port: SCO Unixware 7, by Billy G. Allie.
1185
Guido van Rossum5b08f132001-04-16 02:05:23 +00001186- Updated RISCOS port.
1187
1188- Updated BeOS port and notes.
1189
1190- Various other porting problems resolved.
1191
1192Library
1193
1194- The TERMIOS and SOCKET modules are now truly obsolete and
1195 unnecessary. Their symbols are incorporated in the termios and
1196 socket modules.
1197
1198- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1199 better tests for pickling.
1200
1201- threading: make Condition.wait() robust against KeyboardInterrupt.
1202
1203- zipfile: add support to zipfile to support opening an archive
1204 represented by an open file rather than a file name. Fix bug where
1205 the archive was not properly closed. Fixed a bug in this bugfix
1206 where flush() was called for a read-only file.
1207
1208- imputil: added an uninstall() method to the ImportManager.
1209
1210- Canvas: fixed bugs in lower() and tkraise() methods.
1211
1212- SocketServer: API change (added overridable close_request() method)
1213 so that the TCP server can explicitly close the request.
1214
1215- pstats: Eric Raymond added a simple interactive statistics browser,
1216 invoked when the module is run as a script.
1217
1218- locale: fixed a problem in format().
1219
1220- webbrowser: made it work when the BROWSER environment variable has a
1221 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1222 KDE 2. Fixed some other nits.
1223
1224- unittest: changes to allow using a different exception than
1225 AssertionError, and added a few more function aliases. Some other
1226 small changes.
1227
1228- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1229
1230- asynchat: fixed a critical bug in asynchat that slipped through the
1231 2.1b2 release. Fixed another rare bug.
1232
1233- Fix some unqualified except: clauses (always a bad code example).
1234
1235XML
1236
1237- pyexpat: new API get_version_string().
1238
1239- Fixed some minidom bugs.
1240
1241Extensions
1242
1243- Fixed a core dump in _weakref. Removed the weakref.mapping()
1244 function (it adds nothing to the API).
1245
1246- Rationalized the use of header files in the readline module, to make
1247 it compile (albeit with some warnings) with the very recent readline
1248 4.2, without breaking for earlier versions.
1249
1250- Hopefully fixed a buffering problem in linuxaudiodev.
1251
1252- Attempted a fix to make the OpenSSL support in the socket module
1253 work again with pre-0.9.5 versions of OpenSSL.
1254
1255Tests
1256
1257- Added a test case for asynchat and asyncore.
1258
1259- Removed coupling between tests where one test failing could break
1260 another.
1261
1262Tools
1263
1264- Ping added an interactive help browser to pydoc, fixed some nits
1265 in the rest of the pydoc code, and added some features to his
1266 inspect module.
1267
1268- An updated python-mode.el version 4.1 which integrates Ken
1269 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1270 much nicer in XEmacs and Emacs. When stepping through your program
1271 with pdb, in either the shell window or the *Python* window, the
1272 source file and line will be tracked by an arrow. Very cool!
1273
1274- IDLE: syntax warnings in interactive mode are changed into errors.
1275
1276- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001277 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001278
1279- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001280
Barry Warsaw11e89c72001-04-11 20:37:57 +00001281
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001282What's New in Python 2.1 beta 2?
1283================================
1284
Guido van Rossum053ae352001-03-22 14:17:21 +00001285(Unlisted are many fixed bugs, more documentation, etc.)
1286
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001287Core language, builtins, and interpreter
1288
Guido van Rossum053ae352001-03-22 14:17:21 +00001289- The nested scopes work (enabled by "from __future__ import
1290 nested_scopes") is completed; in particular, the future now extends
1291 into code executed through exec, eval() and execfile(), and into the
1292 interactive interpreter.
1293
1294- When calling a base class method (e.g. BaseClass.__init__(self)),
1295 this is now allowed even if self is not strictly spoken a class
1296 instance (e.g. when using metaclasses or the Don Beaudry hook).
1297
1298- Slice objects are now comparable but not hashable; this prevents
1299 dict[:] from being accepted but meaningless.
1300
1301- Complex division is now calculated using less braindead algorithms.
1302 This doesn't change semantics except it's more likely to give useful
1303 results in extreme cases. Complex repr() now uses full precision
1304 like float repr().
1305
1306- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1307
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001308- It is illegal to assign to the name __debug__, which is set when the
1309 interpreter starts. It is effectively a compile-time constant.
1310
1311- A warning will be issued if a global statement for a variable
1312 follows a use or assignment of that variable.
1313
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001314Standard library
1315
Guido van Rossum053ae352001-03-22 14:17:21 +00001316- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1317 inspired by JUnit), is now part of the standard library. You now
1318 have a choice of two testing frameworks: unittest requires you to
1319 write testcases as separate code, doctest gathers them from
1320 docstrings. Both approaches have their advantages and
1321 disadvantages.
1322
1323- A new module Tix was added, which wraps the Tix extension library
1324 for Tk. With that module, it is not necessary to statically link
1325 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1326 require" command. See Demo/tix/.
1327
1328- tzparse.py is now obsolete.
1329
1330- In gzip.py, the seek() and tell() methods are removed -- they were
1331 non-functional anyway, and it's better if callers can test for their
1332 existence with hasattr().
1333
1334Python/C API
1335
1336- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1337 that's already in the dictionary during a PyDict_Next() iteration.
1338 This used to fail occasionally when a dictionary resize operation
1339 could be triggered that would rehash all the keys. All other
1340 modifications to the dictionary are still off-limits during a
1341 PyDict_Next() iteration!
1342
1343- New extended APIs related to passing compiler variables around.
1344
1345- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1346 implement isinstance() and issubclass().
1347
1348- Py_BuildValue() now has a "D" conversion to create a Python complex
1349 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001350
Fred Drake4e262a92001-03-22 18:26:47 +00001351- Extensions types which support weak references must now set the
1352 field allocated for the weak reference machinery to NULL themselves;
1353 this is done to avoid the cost of checking each object for having a
1354 weakly referencable type in PyObject_INIT(), since most types are
1355 not weakly referencable.
1356
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001357- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1358 free variables and cell variables to and from the frame's f_locals.
1359
1360- Variants of several functions defined in pythonrun.h have been added
1361 to support the nested_scopes future statement. The variants all end
1362 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1363 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1364 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001365 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001366
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001367Distutils
1368
1369- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1370 into the release tree.
1371
Tim Peters0e57abf2001-05-02 07:39:38 +00001372- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001373 (an uninstaller, more customization of the installer's display)
1374
1375- from Jack Jansen: added Mac-specific code to generate a dialog for
1376 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001377 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001378 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001379
1380- added 'platforms' and 'keywords' to the set of metadata that can be
1381 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001382
1383- applied patches from Jason Tishler to make the compiler class work with
1384 Cygwin.
1385
1386
Tim Peters2fe289a2001-03-01 22:19:38 +00001387What's New in Python 2.1 beta 1?
1388================================
Tim Petersd66595f2001-02-04 03:09:53 +00001389
1390Core language, builtins, and interpreter
1391
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001392- Following an outcry from the community about the amount of code
1393 broken by the nested scopes feature introduced in 2.1a2, we decided
1394 to make this feature optional, and to wait until Python 2.2 (or at
1395 least 6 months) to make it standard. The option can be enabled on a
1396 per-module basis by adding "from __future__ import nested_scopes" at
1397 the beginning of a module (before any other statements, but after
1398 comments and an optional docstring). See PEP 236 (Back to the
1399 __future__) for a description of the __future__ statement. PEP 227
1400 (Statically Nested Scopes) has been updated to reflect this change,
1401 and to clarify the semantics in a number of endcases.
1402
1403- The nested scopes code, when enabled, has been hardened, and most
1404 bugs and memory leaks in it have been fixed.
1405
1406- Compile-time warnings are now generated for a number of conditions
1407 that will break or change in meaning when nested scopes are enabled:
1408
1409 - Using "from...import *" or "exec" without in-clause in a function
1410 scope that also defines a lambda or nested function with one or
1411 more free (non-local) variables. The presence of the import* or
1412 bare exec makes it impossible for the compiler to determine the
1413 exact set of local variables in the outer scope, which makes it
1414 impossible to determine the bindings for free variables in the
1415 inner scope. To avoid the warning about import *, change it into
1416 an import of explicitly name object, or move the import* statement
1417 to the global scope; to avoid the warning about bare exec, use
1418 exec...in... (a good idea anyway -- there's a possibility that
1419 bare exec will be deprecated in the future).
1420
1421 - Use of a global variable in a nested scope with the same name as a
1422 local variable in a surrounding scope. This will change in
1423 meaning with nested scopes: the name in the inner scope will
1424 reference the variable in the outer scope rather than the global
1425 of the same name. To avoid the warning, either rename the outer
1426 variable, or use a global statement in the inner function.
1427
Neil Schemenauera35c6882001-02-27 04:45:05 +00001428- An optional object allocator has been included. This allocator is
1429 optimized for Python objects and should be faster and use less memory
1430 than the standard system allocator. It is not enabled by default
1431 because of possible thread safety problems. The allocator is only
1432 protected by the Python interpreter lock and it is possible that some
1433 extension modules require a thread safe allocator. The object
1434 allocator can be enabled by providing the "--with-pymalloc" option to
1435 configure.
1436
Tim Petersd66595f2001-02-04 03:09:53 +00001437Standard library
1438
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001439- pyexpat now detects the expat version if expat.h defines it. A
1440 number of additional handlers are provided, which are only available
1441 since expat 1.95. In addition, the methods SetParamEntityParsing and
1442 GetInputContext of Parser objects are available with 1.95.x
1443 only. Parser objects now provide the ordered_attributes and
1444 specified_attributes attributes. A new module expat.model was added,
1445 which offers a number of additional constants if 1.95.x is used.
1446
1447- xml.dom offers the new functions registerDOMImplementation and
1448 getDOMImplementation.
1449
1450- xml.dom.minidom offers a toprettyxml method. A number of DOM
1451 conformance issues have been resolved. In particular, Element now
1452 has an hasAttributes method, and the handling of namespaces was
1453 improved.
1454
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001455- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1456 getting information about live Python code, and pydoc.py, a module
1457 for interactively converting docstrings to HTML or text.
1458 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001459 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001460 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1461 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001462
Tim Peters1eff7962001-03-01 02:31:33 +00001463- New library module difflib.py, primarily packaging the SequenceMatcher
1464 class at the heart of the popular ndiff.py file-comparison tool.
1465
1466- doctest.py (a framework for verifying Python code examples in docstrings)
1467 is now part of the std library.
1468
Tim Petersd66595f2001-02-04 03:09:53 +00001469Windows changes
1470
Guido van Rossume3955a82001-03-02 14:05:59 +00001471- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1472 small GUI that lets you browse the module docstrings using your
1473 default web browser.
1474
Tim Peters1eff7962001-03-01 02:31:33 +00001475- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1476 Platforms) is implemented. See
1477
1478 http://python.sourceforge.net/peps/pep-0235.html
1479
1480 for full details, especially the "Current Lower-Left Semantics" section.
1481 The new Windows import rules are simpler than before:
1482
1483 A. If the PYTHONCASEOK environment variable exists, same as
1484 before: silently accept the first case-insensitive match of any
1485 kind; raise ImportError if none found.
1486
1487 B. Else search sys.path for the first case-sensitive match; raise
1488 ImportError if none found.
1489
1490 The same rules have been implented on other platforms with case-
1491 insensitive but case-preserving filesystems too (including Cygwin, and
1492 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001493
Tim Peters25a9ce32001-02-19 07:06:36 +00001494- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1495 what it's supposed to do (and does do under NT and 2000) via direct
1496 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001497 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001498 all Win9x systems before.
1499
Tim Peters1eff7962001-03-01 02:31:33 +00001500- Build: Subproject _test (effectively) renamed to _testcapi.
1501
Tim Peters2fe289a2001-03-01 22:19:38 +00001502New platforms
1503
1504- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1505 Thanks to Steven Majewski!
1506
1507- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1508 Tishler!
1509
Guido van Rossum9089b272001-03-02 06:49:50 +00001510- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1511 Schwertberger! See RISCOS/README for more information -- it seems
1512 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001513 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001514
Tim Peters25a9ce32001-02-19 07:06:36 +00001515
Tim Petersd7b5e882001-01-25 03:36:26 +00001516What's New in Python 2.1 alpha 2?
1517=================================
Tim Peters40ead762001-01-27 05:35:26 +00001518
Tim Petersd7b5e882001-01-25 03:36:26 +00001519Core language, builtins, and interpreter
1520
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001521- Scopes nest. If a name is used in a function or class, but is not
1522 local, the definition in the nearest enclosing function scope will
1523 be used. One consequence of this change is that lambda statements
1524 could reference variables in the namespaces where the lambda is
1525 defined. In some unusual cases, this change will break code.
1526
1527 In all previous version of Python, names were resolved in exactly
1528 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001529 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001530 function A is defined within a function B, the names bound in B are
1531 not visible in A. The new rules make names bound in B visible in A,
1532 unless A contains a name binding that hides the binding in B.
1533
1534 Section 4.1 of the reference manual describes the new scoping rules
1535 in detail. The test script in Lib/test/test_scope.py demonstrates
1536 some of the effects of the change.
1537
1538 The new rules will cause existing code to break if it defines nested
1539 functions where an outer function has local variables with the same
1540 name as globals or builtins used by the inner function. Example:
1541
1542 def munge(str):
1543 def helper(x):
1544 return str(x)
1545 if type(str) != type(''):
1546 str = helper(str)
1547 return str.strip()
1548
1549 Under the old rules, the name str in helper() is bound to the
1550 builtin function str(). Under the new rules, it will be bound to
1551 the argument named str and an error will occur when helper() is
1552 called.
1553
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001554- The compiler will report a SyntaxError if "from ... import *" occurs
1555 in a function or class scope. The language reference has documented
1556 that this case is illegal, but the compiler never checked for it.
1557 The recent introduction of nested scope makes the meaning of this
1558 form of name binding ambiguous. In a future release, the compiler
1559 may allow this form when there is no possibility of ambiguity.
1560
Tim Peters40ead762001-01-27 05:35:26 +00001561- repr(string) is easier to read, now using hex escapes instead of octal,
1562 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1563
1564 >>> "\texample \r\n" + chr(0) + chr(255)
1565 '\texample \r\n\x00\xff' # in 2.1
1566 '\011example \015\012\000\377' # in 2.0
1567
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001568- Functions are now compared and hashed by identity, not by value, since
1569 the func_code attribute is writable.
1570
Fred Drakefb9d7122001-02-01 20:00:40 +00001571- Weak references (PEP 205) have been added. This involves a few
1572 changes in the core, an extension module (_weakref), and a Python
1573 module (weakref). The weakref module is the public interface. It
1574 includes support for "explicit" weak references, proxy objects, and
1575 mappings with weakly held values.
1576
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001577- A 'continue' statement can now appear in a try block within the body
1578 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001579 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001580
Tim Petersd7b5e882001-01-25 03:36:26 +00001581Standard library
1582
Barry Warsaw30dbd142001-01-31 22:14:01 +00001583- mailbox.py now has a new class, PortableUnixMailbox which is
1584 identical to UnixMailbox but uses a more portable scheme for
1585 determining From_ separators. Also, the constructors for all the
1586 classes in this module have a new optional `factory' argument, which
1587 is a callable used when new message classes must be instantiated by
1588 the next() method.
1589
Tim Petersd7b5e882001-01-25 03:36:26 +00001590- random.py is now self-contained, and offers all the functionality of
1591 the now-deprecated whrandom.py. See the docs for details. random.py
1592 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001593 and restoring the internal state of the generator; and jumpahead(n),
1594 for quickly forcing the internal state to be the same as if n calls to
1595 random() had been made. The latter is particularly useful for multi-
1596 threaded programs, creating one instance of the random.Random() class for
1597 each thread, then using .jumpahead() to force each instance to use a
1598 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001599
Tim Peters0de88fc2001-02-01 04:59:18 +00001600- random.py's seed() function is new. For bit-for-bit compatibility with
1601 prior releases, use the whseed function instead. The new seed function
1602 addresses two problems: (1) The old function couldn't produce more than
1603 about 2**24 distinct internal states; the new one about 2**45 (the best
1604 that can be done in the Wichmann-Hill generator). (2) The old function
1605 sometimes produced identical internal states when passed distinct
1606 integers, and there was no simple way to predict when that would happen;
1607 the new one guarantees to produce distinct internal states for all
1608 arguments in [0, 27814431486576L).
1609
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001610- The socket module now supports raw packets on Linux. The socket
1611 family is AF_PACKET.
1612
Tim Peters9ea17ac2001-02-02 05:57:15 +00001613- test_capi.py is a start at running tests of the Python C API. The tests
1614 are implemented by the new Modules/_testmodule.c.
1615
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001616- A new extension module, _symtable, provides provisional access to the
1617 internal symbol table used by the Python compiler. A higher-level
1618 interface will be added on top of _symtable in a future release.
1619
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001620- Removed the obsolete soundex module.
1621
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001622- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1623 the isSameNode method; NamedNodeMap the get method.
1624
1625- xml.sax.expatreader supports the lexical handler property; it
1626 generates comment, startCDATA, and endCDATA events.
1627
Tim Petersee826f82001-01-31 19:39:44 +00001628Windows changes
1629
1630- Build procedure: the zlib project is built in a different way that
1631 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001632 the zlib binary used. See PCbuild\readme.txt for details. Your old
1633 zlib-related directories can be deleted; you'll need to download fresh
1634 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001635
Tim Peters9ea17ac2001-02-02 05:57:15 +00001636- Build: New subproject _test for the benefit of test_capi.py (see above).
1637
Tim Petersb16c56f2001-02-02 21:24:51 +00001638- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1639 interface to some Python compiler internals).
1640
1641- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001642 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001643
Tim Petersa3a3a032000-11-30 05:22:44 +00001644What's New in Python 2.1 alpha 1?
1645=================================
1646
1647Core language, builtins, and interpreter
1648
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001649- There is a new Unicode companion to the PyObject_Str() API
1650 called PyObject_Unicode(). It behaves in the same way as the
1651 former, but assures that the returned value is an Unicode object
1652 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001653
Guido van Rossumf98eda02001-01-17 15:54:45 +00001654- The comparison operators support "rich comparison overloading" (PEP
1655 207). C extension types can provide a rich comparison function in
1656 the new tp_richcompare slot in the type object. The cmp() function
1657 and the C function PyObject_Compare() first try the new rich
1658 comparison operators before trying the old 3-way comparison. There
1659 is also a new C API PyObject_RichCompare() (which also falls back on
1660 the old 3-way comparison, but does not constrain the outcome of the
1661 rich comparison to a Boolean result).
1662
1663 The rich comparison function takes two objects (at least one of
1664 which is guaranteed to have the type that provided the function) and
1665 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1666 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1667 object, which may be NotImplemented (in which case the tp_compare
1668 slot function is used as a fallback, if defined).
1669
1670 Classes can overload individual comparison operators by defining one
1671 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001672 __ge__. There are no explicit "reflected argument" versions of
1673 these; instead, __lt__ and __gt__ are each other's reflection,
1674 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1675 reflection (similar at the C level). No other implications are
1676 made; in particular, Python does not assume that == is the Boolean
1677 inverse of !=, or that < is the Boolean inverse of >=. This makes
1678 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001679
1680 Classes or types that want to implement (in)equality tests but not
1681 the ordering operators (i.e. unordered types) should implement ==
1682 and !=, and raise an error for the ordering operators.
1683
Guido van Rossuma88479f2001-01-18 14:28:08 +00001684 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001685 Boolean; e.g. a matrix type might want to return a matrix of bits
1686 for A < B, giving elementwise comparisons. Such types should ensure
1687 that any interpretation of their value in a Boolean context raises
1688 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1689 at the C level) to always raise an exception.
1690
Guido van Rossuma88479f2001-01-18 14:28:08 +00001691- Complex numbers use rich comparisons to define == and != but raise
1692 an exception for <, <=, > and >=. Unfortunately, this also means
1693 that cmp() of two complex numbers raises an exception when the two
1694 numbers differ. Since it is not mathematically meaningful to compare
1695 complex numbers except for equality, I hope that this doesn't break
1696 too much code.
1697
Tim Peters3389f192001-02-18 08:48:49 +00001698- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001699 not defined by the language, other than that it's arbitrary but
1700 consistent (see the Reference Manual). An implementation detail changed
1701 in 2.1a1 such that None now compares less than any other object. Code
1702 relying on this new behavior (like code that relied on the previous
1703 behavior) does so at its own risk.
1704
Barry Warsaw573b5412001-01-15 20:43:18 +00001705- Functions and methods now support getting and setting arbitrarily
1706 named attributes (PEP 232). Functions have a new __dict__
1707 (a.k.a. func_dict) which hold the function attributes. Methods get
1708 and set attributes on their underlying im_func. It is a TypeError
1709 to set an attribute on a bound method.
1710
Guido van Rossum051e3352001-01-15 19:11:10 +00001711- The xrange() object implementation has been improved so that
1712 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1713 limitation that in this case len(xrange(sys.maxint)) can't be
1714 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1715 work fine as long as the index i doesn't actually reach 2**31.
1716 (Python uses regular ints for sequence and string indices; fixing
1717 that is much more work.)
1718
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001719- Two changes to from...import:
1720
Guido van Rossumba381232001-02-03 15:06:40 +00001721 1) "from M import X" now works even if (after loading module M)
1722 sys.modules['M'] is not a real module; it's basically a getattr()
1723 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001724
1725 2) "from M import *" now looks for M.__all__ to decide which names to
1726 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1727 filters out names starting with '_' as before. Whether or not
1728 __all__ exists, there's no restriction on the type of M.
1729
Guido van Rossumf61f1662001-01-10 20:13:55 +00001730- File objects have a new method, xreadlines(). This is the fastest
1731 way to iterate over all lines in a file:
1732
1733 for line in file.xreadlines():
1734 ...do something to line...
1735
1736 See the xreadlines module (mentioned below) for how to do this for
1737 other file-like objects.
1738
1739- Even if you don't use file.xreadlines(), you may expect a speedup on
1740 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001741 quite a bit in platform-specific ways: on systems (like Linux) that
1742 support flockfile(), getc_unlocked(), and funlockfile(), those are
1743 used by default. On systems (like Windows) without getc_unlocked(),
1744 a complicated (but still thread-safe) method using fgets() is used by
1745 default.
1746
Tim Petersd52269b2001-01-25 06:23:18 +00001747 You can force use of the fgets() method by #define'ing
1748 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001749 getc_unlocked()).
1750
Tim Petersd52269b2001-01-25 06:23:18 +00001751 You can force fgets() not to be used by #define'ing
1752 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001753 test_bufio.py fails -- and let us know if it does!).
1754
1755- In addition, the fileinput module, while still slower than the other
1756 methods on most platforms, has been sped up too, by using
1757 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001758
1759- Support for run-time warnings has been added, including a new
1760 command line option (-W) to specify the disposition of warnings.
1761 See the description of the warnings module below.
1762
1763- Extensive changes have been made to the coercion code. This mostly
1764 affects extension modules (which can now implement mixed-type
1765 numerical operators without having to use coercion), but
1766 occasionally, in boundary cases the coercion semantics have changed
1767 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001768 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001769 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001770 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001771
Guido van Rossumf98eda02001-01-17 15:54:45 +00001772- In connection with the coercion changes, a new built-in singleton
1773 object, NotImplemented is defined. This can be returned for
1774 operations that wish to indicate they are not implemented for a
1775 particular combination of arguments. From C, this is
1776 Py_NotImplemented.
1777
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001778- The interpreter accepts now bytecode files on the command line even
1779 if they do not have a .pyc or .pyo extension. On Linux, after executing
1780
Martin v. Löwise214baa2001-02-04 22:37:56 +00001781import imp,sys,string
1782magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1783reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1784open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001785
1786 any byte code file can be used as an executable (i.e. as an argument
1787 to execve(2)).
1788
Tim Peters9940b802000-12-01 07:59:35 +00001789- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001790 character. In 1.6 and earlier, they never produced a sign,
1791 and raised an error if the value of the long was too large
1792 to fit in a Python int. In 2.0, they produced a sign if and
1793 only if too large to fit in an int. This was inconsistent
1794 across platforms (because the size of an int varies across
1795 platforms), and inconsistent with hex() and oct(). Example:
1796
1797 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001798 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001799 'ffffffbe' # in 2.0 and before, on 32-bit machines
1800 >>> hex(-0x42L)
1801 '-0x42L' # in all versions of Python
1802
Tim Peters9940b802000-12-01 07:59:35 +00001803 The behavior of %d formats for negative Python longs remains
1804 the same as in 2.0 (although in 1.6 and before, they raised
1805 an error if the long didn't fit in a Python int).
1806
1807 %u formats don't make sense for Python longs, but are allowed
1808 and treated the same as %d in 2.1. In 2.0, a negative long
1809 formatted via %u produced a sign if and only if too large to
1810 fit in an int. In 1.6 and earlier, a negative long formatted
1811 via %u raised an error if it was too big to fit in an int.
1812
Guido van Rossum3661d392000-12-12 22:10:31 +00001813- Dictionary objects have an odd new method, popitem(). This removes
1814 an arbitrary item from the dictionary and returns it (in the form of
1815 a (key, value) pair). This can be useful for algorithms that use a
1816 dictionary as a bag of "to do" items and repeatedly need to pick one
1817 item. Such algorithms normally end up running in quadratic time;
1818 using popitem() they can usually be made to run in linear time.
1819
Tim Peters36cdad12000-12-29 02:06:45 +00001820Standard library
1821
Thomas Woutersfe385252001-01-19 23:16:56 +00001822- In the time module, the time argument to the functions strftime,
1823 localtime, gmtime, asctime and ctime is now optional, defaulting to
1824 the current time (in the local timezone).
1825
Guido van Rossumda91f222001-01-15 16:36:08 +00001826- The ftplib module now defaults to passive mode, which is deemed a
1827 more useful default given that clients are often inside firewalls
1828 these days. Note that this could break if ftplib is used to connect
1829 to a *server* that is inside a firewall, from outside; this is
1830 expected to be a very rare situation. To fix that, you can call
1831 ftp.set_pasv(0).
1832
Martin v. Löwis10a27872001-01-13 09:54:41 +00001833- The module site now treats .pth files not only for path configuration,
1834 but also supports extensions to the initialization code: Lines starting
1835 with import are executed.
1836
Guido van Rossumf61f1662001-01-10 20:13:55 +00001837- There's a new module, warnings, which implements a mechanism for
1838 issuing and filtering warnings. There are some new built-in
1839 exceptions that serve as warning categories, and a new command line
1840 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1841 turns warnings into errors). warnings.warn(message[, category])
1842 issues a warning message; this can also be called from C as
1843 PyErr_Warn(category, message).
1844
1845- A new module xreadlines was added. This exports a single factory
1846 function, xreadlines(). The intention is that this code is the
1847 absolutely fastest way to iterate over all lines in an open
1848 file(-like) object:
1849
1850 import xreadlines
1851 for line in xreadlines.xreadlines(file):
1852 ...do something to line...
1853
1854 This is equivalent to the previous the speed record holder using
1855 file.readlines(sizehint). Note that if file is a real file object
1856 (as opposed to a file-like object), this is equivalent:
1857
1858 for line in file.xreadlines():
1859 ...do something to line...
1860
Tim Peters36cdad12000-12-29 02:06:45 +00001861- The bisect module has new functions bisect_left, insort_left,
1862 bisect_right and insort_right. The old names bisect and insort
1863 are now aliases for bisect_right and insort_right. XXX_right
1864 and XXX_left methods differ in what happens when the new element
1865 compares equal to one or more elements already in the list: the
1866 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001867 right. Code that doesn't care where equal elements end up should
1868 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001869
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001870- The new curses.panel module wraps the panel library that forms part
1871 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1872
Guido van Rossumf61f1662001-01-10 20:13:55 +00001873- The SocketServer module now sets the allow_reuse_address flag by
1874 default in the TCPServer class.
1875
1876- A new function, sys._getframe(), returns the stack frame pointer of
1877 the caller. This is intended only as a building block for
1878 higher-level mechanisms such as string interpolation.
1879
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001880- The pyexpat module supports a number of new handlers, which are
1881 available only in expat 1.2. If invocation of a callback fails, it
1882 will report an additional frame in the traceback. Parser objects
1883 participate now in garbage collection. If expat reports an unknown
1884 encoding, pyexpat will try to use a Python codec; that works only
1885 for single-byte charsets. The parser type objects is exposed as
1886 XMLParserObject.
1887
1888- xml.dom now offers standard definitions for symbolic node type and
1889 exception code constants, and a hierarchy of DOM exceptions. minidom
1890 was adjusted to use them.
1891
1892- The conformance of xml.dom.minidom to the DOM specification was
1893 improved. It detects a number of additional error cases; the
1894 previous/next relationship works even when the tree is modified;
1895 Node supports the normalize() method; NamedNodeMap, DocumentType and
1896 DOMImplementation classes were added; Element supports the
1897 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1898 method.
1899
Guido van Rossumf61f1662001-01-10 20:13:55 +00001900Build issues
1901
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001902- For Unix (and Unix-compatible) builds, configuration and building of
1903 extension modules is now greatly automated. Rather than having to
1904 edit the Modules/Setup file to indicate which modules should be
1905 built and where their include files and libraries are, a
1906 distutils-based setup.py script now takes care of building most
1907 extension modules. All extension modules built this way are built
1908 as shared libraries. Only a few modules that must be linked
1909 statically are still listed in the Setup file; you won't need to
1910 edit their configuration.
1911
1912- Python should now build out of the box on Cygwin. If it doesn't,
1913 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001914
1915- Python now always uses its own (renamed) implementation of getopt()
1916 -- there's too much variation among C library getopt()
1917 implementations.
1918
1919- C++ compilers are better supported; the CXX macro is always set to a
1920 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001921
Tim Petersd92dfe02000-12-12 01:18:41 +00001922Windows changes
1923
1924- select module: By default under Windows, a select() call
1925 can specify no more than 64 sockets. Python now boosts
1926 this Microsoft default to 512. If you need even more than
1927 that, see the MS docs (you'll need to #define FD_SETSIZE
1928 and recompile Python from source).
1929
Guido van Rossumf61f1662001-01-10 20:13:55 +00001930- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1931 subdirectory is no more!
1932
Tim Petersa3a3a032000-11-30 05:22:44 +00001933
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001934What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001935=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001936
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001937Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001938changes are in the file HISTORY. If you are making the jump directly
1939from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1940HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001941
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001942Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1943the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1944http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001945
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001946--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001947
1948======================================================================
1949
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001950What's new in 2.0 (since release candidate 1)?
1951==============================================
1952
1953Standard library
1954
1955- The copy_reg module was modified to clarify its intended use: to
1956 register pickle support for extension types, not for classes.
1957 pickle() will raise a TypeError if it is passed a class.
1958
1959- Fixed a bug in gettext's "normalize and expand" code that prevented
1960 it from finding an existing .mo file.
1961
1962- Restored support for HTTP/0.9 servers in httplib.
1963
Tim Peters989b7b92000-10-16 20:24:53 +00001964- The math module was changed to stop raising OverflowError in case of
1965 underflow, and return 0 instead in underflow cases. Whether Python
1966 used to raise OverflowError in case of underflow was platform-
1967 dependent (it did when the platform math library set errno to ERANGE
1968 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001969
1970- Fixed a bug in StringIO that occurred when the file position was not
1971 at the end of the file and write() was called with enough data to
1972 extend past the end of the file.
1973
1974- Fixed a bug that caused Tkinter error messages to get lost on
1975 Windows. The bug was fixed by replacing direct use of
1976 interp->result with Tcl_GetStringResult(interp).
1977
1978- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1979 redirect response.
1980
1981- Several changes were made to distutils: Some debugging code was
1982 removed from util. Fixed the installer used when an external zip
1983 program (like WinZip) is not found; the source code for this
1984 installer is in Misc/distutils. check_lib() was modified to behave
1985 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1986 test for whether installed modules are on sys.path was changed to
1987 use both normcase() and normpath().
1988
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001989- Several minor bugs were fixed in the xml package (the minidom,
1990 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001991
1992- The regression test driver (regrtest.py) behavior when invoked with
1993 -l changed: It now reports a count of objects that are recognized as
1994 garbage but not freed by the garbage collector.
1995
Tim Peters989b7b92000-10-16 20:24:53 +00001996- The regression test for the math module was changed to test
1997 exceptional behavior when the test is run in verbose mode. Python
1998 cannot yet guarantee consistent exception behavior across platforms,
1999 so the exception part of test_math is run only in verbose mode, and
2000 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002001
2002Internals
2003
2004- PyOS_CheckStack() has been disabled on Win64, where it caused
2005 test_sre to fail.
2006
2007Build issues
2008
2009- Changed compiler flags, so that gcc is always invoked with -Wall and
2010 -Wstrict-prototypes. Users compiling Python with GCC should see
2011 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002012 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002013 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002014
Tim Petersa3a3a032000-11-30 05:22:44 +00002015- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002016
2017Tools and other miscellany
2018
2019- The compiler in Tools/compiler was updated to support the new
2020 language features introduced in 2.0: extended print statement, list
2021 comprehensions, and augmented assignments. The new compiler should
2022 also be backwards compatible with Python 1.5.2; the compiler will
2023 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002024 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002025
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002026What's new in 2.0 release candidate 1 (since beta 2)?
2027=====================================================
2028
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002029What is release candidate 1?
2030
2031We believe that release candidate 1 will fix all known bugs that we
2032intend to fix for the 2.0 final release. This release should be a bit
2033more stable than the previous betas. We would like to see even more
2034widespread testing before the final release, so we are producing this
2035release candidate. The final release will be exactly the same unless
2036any show-stopping (or brown bag) bugs are found by testers of the
2037release candidate.
2038
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002039All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002040to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002041
2042Core language, builtins, and interpreter
2043
2044- A bug that caused crashes when __coerce__ was used with augmented
2045 assignment, e.g. +=, was fixed.
2046
2047- Raise ZeroDivisionError when raising zero to a negative number,
2048 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2049 power operator and the result of math.pow(0.0, -2.0) will vary by
2050 platform. On Linux, it raises a ValueError.
2051
2052- A bug in Unicode string interpolation was fixed that occasionally
2053 caused errors with formats including "%%". For example, the
2054 following expression "%% %s" % u"abc" no longer raises a TypeError.
2055
2056- Compilation of deeply nested expressions raises MemoryError instead
2057 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2058
2059- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2060 rendering them useless. They are now written in binary mode again.
2061
2062Standard library
2063
2064- Keyword arguments are now accepted for most pattern and match object
2065 methods in SRE, the standard regular expression engine.
2066
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002067- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002068 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002069
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002070- Several bugs in the Unicode handling and error handling in _tkinter
2071 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002072
2073- Fix memory management errors in Merge() and Tkapp_Call() routines.
2074
2075- Several changes were made to cStringIO to make it compatible with
2076 the file-like object interface and with StringIO. If operations are
2077 performed on a closed object, an exception is raised. The truncate
2078 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002079 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002080
2081- There were many changes made to the linuxaudiodev module and its
2082 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002083 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002084
2085 Note that this module is named poorly, because it should work
2086 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002087 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002088
2089 The module now raises exceptions when errors occur instead of
2090 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2091 audio) and defines a getptr() method that calls the
2092 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2093
2094- The library_version attribute, introduced in an earlier beta, was
2095 removed because it can not be supported with early versions of the C
2096 readline library, which provides no way to determine the version at
2097 compile-time.
2098
2099- The binascii module is now enabled on Win64.
2100
Tim Peters46446d62000-10-09 21:19:31 +00002101- tokenize.py no longer suffers "recursion depth" errors when parsing
2102 programs with very long string literals.
2103
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002104Internals
2105
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002106- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002107 which is called when the interpreter starts up to determine where
2108 the standard library is installed. These vulnerabilities affect all
2109 previous versions of Python and can be exploited by setting very
2110 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2111 setuid Python script, although use of the wrapper in
2112 Misc/setuid-prog.c will eliminate the vulnerability.
2113
2114- Fixed garbage collection bugs in instance creation that were
2115 triggered when errors occurred during initialization. The solution,
2116 applied in cPickle and in PyInstance_New(), is to call
2117 PyObject_GC_Init() after the initialization of the object's
2118 container attributes is complete.
2119
2120- pyexpat adds definitions of PyModule_AddStringConstant and
2121 PyModule_AddObject if the Python version is less than 2.0, which
2122 provides compatibility with PyXML on Python 1.5.2.
2123
2124- If the platform has a bogus definition for LONG_BIT (the number of
2125 bits in a long), an error will be reported at compile time.
2126
2127- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2128 collection crashes and possibly other, unreported crashes.
2129
2130- Fixed a memory leak in _PyUnicode_Fini().
2131
2132Build issues
2133
2134- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002135 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002136 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002137
2138- The mmap.PAGESIZE constant is now initialized using sysconf when
2139 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2140
2141- The md5 file should now compile on all platforms.
2142
2143- The select module now compiles on platforms that do not define
2144 POLLRDNORM and related constants.
2145
2146- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002147 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002148
Jeremy Hylton10921202000-10-09 18:34:12 +00002149- BeOS: A number of changes were made to the build and installation
2150 process. ar-fake now operates on a directory of object files.
2151 dl_export.h is gone, and its macros now appear on the mwcc command
2152 line during build on PPC BeOS.
2153
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002154- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002155 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002156
2157- Cygwin: Support for shared libraries, Tkinter, and sockets.
2158
2159- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2160
2161Tools and other miscellany
2162
2163- Removed debugging prints from main used with freeze.
2164
Tim Peters46446d62000-10-09 21:19:31 +00002165- IDLE auto-indent no longer crashes when it encounters Unicode
2166 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002167
2168What's new in 2.0 beta 2 (since beta 1)?
2169========================================
2170
2171Core language, builtins, and interpreter
2172
Tim Peters482c0212000-09-26 06:33:09 +00002173- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002174 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002175
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002176- Add -h and -V command line options to print the usage message and
2177 Python version number and exit immediately.
2178
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002179- eval() and exec accept Unicode objects as code parameters.
2180
2181- getattr() and setattr() now also accept Unicode objects for the
2182 attribute name, which are converted to strings using the default
2183 encoding before lookup.
2184
2185- Multiplication on string and Unicode now does proper bounds
2186 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2187 string is too long."
2188
2189- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002190 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002191
Jeremy Hylton1b618592000-09-26 05:32:36 +00002192
2193Standard library and extensions
2194
Guido van Rossum5b08f132001-04-16 02:05:23 +00002195- socket module: the OpenSSL code now adds support for RAND_status()
2196 and EGD (Entropy Gathering Device).
2197
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002198- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002199 argument checking; it still takes no arguments.
2200
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002201- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002202
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002203- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002204
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002205- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002206
2207- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002208 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002209
2210- copy: Copy Unicode objects atomically.
2211
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002212- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002213
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002214- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002215
Fred Drake67233bc2000-09-26 16:40:27 +00002216- dbm: Add get() and setdefault() methods to dbm object. Add constant
2217 `library' to module that names the library used. Added doc strings
2218 and method names to error messages. Uses configure to determine
2219 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2220 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002221
2222- distutils: Update to version 0.9.3.
2223
2224- dl: Add several dl.RTLD_ constants.
2225
2226- fpectl: Now supported on FreeBSD.
2227
2228- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2229 found by the collector will be saved in gc.garbage. This is useful
2230 for debugging a program that creates reference cycles.
2231
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002232- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002233 of HTTP class. Do not close socket on zero-length response. Do not
2234 crash when server sends invalid content-length header.
2235
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002236- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002237
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002238- marshal: When reading a short, sign-extend on platforms where shorts
2239 are bigger than 16 bits. When reading a long, repair the unportable
2240 sign extension that was being done for 64-bit machines. (It assumed
2241 that signed right shift sign-extends.)
2242
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002243- operator: Add contains(), invert(), __invert__() as aliases for
2244 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002245
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002246- os: Add support for popen2() and popen3() on all platforms where
2247 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002248
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002249- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002250 clicking on a file in Explorer (or passing the file name to the
2251 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002252
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002253- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002254 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002255
2256- pickle: Now raises ValueError when an invalid pickle that contains
2257 a non-string repr where a string repr was expected. This behavior
2258 matches cPickle.
2259
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002260- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002261
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002262- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002263
2264- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002265 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002266 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002267
2268- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002269 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002270
2271- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002272 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002273 few cycles during startup since the first call to
2274 setdefaultencoding() will initialize the codec registry and the
2275 encodings package.
2276
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002277- socket: Support for size hint in readlines() method of object returned
2278 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002279
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002280- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002281 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002282 is followed by whitespace.
2283
Tim Petersa3a3a032000-11-30 05:22:44 +00002284- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002285
2286- struct: Check ranges for bytes and shorts.
2287
2288- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002289 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002290
2291- Tkinter: Image objects are now guaranteed to have unique ids. Set
2292 event.delta to zero if Tk version doesn't support mousewheel.
2293 Removed some debugging prints.
2294
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002295- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002296
Fred Drake67233bc2000-09-26 16:40:27 +00002297- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002298 which works around a bug in Norton AntiVirus 2000 that leads directly
2299 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002300
2301- xml: New version detection code allows PyXML to override standard
2302 XML package if PyXML version is greater than 0.6.1.
2303
Fred Drake64bb3802000-09-26 16:21:35 +00002304- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2305 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2306 tree only for nodes which are sufficiently interesting to a specific
2307 application. Does not provide the HTML-specific extensions. Still
2308 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002309
Fred Drake64bb3802000-09-26 16:21:35 +00002310- xml.sax: SAX 2 support for Python, including all the handler
2311 interfaces needed to process XML 1.0 compliant XML. Some
2312 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002313
Fred Drake64bb3802000-09-26 16:21:35 +00002314- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2315 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002316
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002317
Jeremy Hylton1b618592000-09-26 05:32:36 +00002318C API
2319
2320- Add three new convenience functions for module initialization --
2321 PyModule_AddObject(), PyModule_AddIntConstant(), and
2322 PyModule_AddStringConstant().
2323
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002324- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002325 removed and add #error to Python.h if NULL isn't defined after
2326 #include of stdio.h.
2327
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002328- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002329 backwards compatibility (at the source level) with old extensions.
2330
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002331- A wrapper API was added for signal() and sigaction(). Instead of
2332 either function, always use PyOS_getsig() to get a signal handler
2333 and PyOS_setsig() to set one. A new convenience typedef
2334 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002335
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002336- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002337 internal data buffer and size of a string object -- or the default
2338 encoded version of a Unicode object.
2339
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002340- PyString_Size() and PyString_AsString() accept Unicode objects.
2341
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002342- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002343 exists). INT_MAX and LONG_MAX will always be defined, even if
2344 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002345
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002346- PyFloat_FromString takes a second argument, pend, that was
2347 effectively useless. It is now officially useless but preserved for
2348 backwards compatibility. If the pend argument is not NULL, *pend is
2349 set to NULL.
2350
2351- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2352 for the attribute name. See note on getattr() above.
2353
2354- A few bug fixes to argument processing for Unicode.
2355 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2356 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2357 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002358 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002359
2360- Py_BuildValue accepts B format (for bgen-generated code).
2361
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002362
Jeremy Hylton1b618592000-09-26 05:32:36 +00002363Internals
2364
2365- On Unix, fix code for finding Python installation directory so that
2366 it works when argv[0] is a relative path.
2367
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002368- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002369 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002370 rather than by generating a copy of the object.
2371
Tim Peters482c0212000-09-26 06:33:09 +00002372- Several of the internal Unicode tables are much smaller now, and
2373 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002374
Jeremy Hylton97693b02000-09-26 17:42:51 +00002375- In the garbage collector: Fixed bug in collection of tuples. Fixed
2376 bug that caused some instances to be removed from the container set
2377 while they were still live. Fixed parsing in gc.set_debug() for
2378 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002379
2380- Fixed refcount problem in instance deallocation that only occurred
2381 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2382
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002383- On Windows, getpythonregpath is now protected against null data in
2384 registry key.
2385
2386- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002387 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002388
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002389
Jeremy Hylton1b618592000-09-26 05:32:36 +00002390Build and platform-specific issues
2391
2392- Better support of GNU Pth via --with-pth configure option.
2393
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002394- Python/C API now properly exposed to dynamically-loaded extension
2395 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002396
2397- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2398 Don't define MS_SYNC to be zero when it is undefined. Added missing
2399 prototypes in posixmodule.c.
2400
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002401- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002402 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002403
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002404- Fix largefile support on older NetBSD systems and OpenBSD by adding
2405 define for TELL64.
2406
2407
2408Tools and other miscellany
2409
2410- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2411
2412- freeze: The modulefinder now works with 2.0 opcodes.
2413
Tim Petersa3a3a032000-11-30 05:22:44 +00002414- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002415 Move hackery of sys.argv until after the Tk instance has been
2416 created, which allows the application-specific Tkinter
2417 initialization to be executed if present; also pass an explicit
2418 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002419
Jeremy Hylton1b618592000-09-26 05:32:36 +00002420
2421What's new in 2.0 beta 1?
2422=========================
2423
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002424Source Incompatibilities
2425------------------------
2426
2427None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2428such as single-argument append(), connect() and bind(), and changes to
2429str(long) and repr(float).
2430
2431
2432Binary Incompatibilities
2433------------------------
2434
2435- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2436with Python 2.0; these extensions will have to be rebuilt for Python
24372.0.
2438
2439- On Windows, attempting to import a third party extension built for
2440Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2441can do about this. Check your PYTHONPATH environment variable!
2442
2443- Python bytecode files (*.pyc and *.pyo) are not compatible between
2444releases.
2445
2446
2447Overview of Changes Since 1.6
2448-----------------------------
2449
2450There are many new modules (including brand new XML support through
2451the xml package, and i18n support through the gettext module); a list
2452of all new modules is included below. Lots of bugs have been fixed.
2453
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002454The process for making major new changes to the language has changed
2455since Python 1.6. Enhancements must now be documented by a Python
2456Enhancement Proposal (PEP) before they can be accepted.
2457
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002458There are several important syntax enhancements, described in more
2459detail below:
2460
2461 - Augmented assignment, e.g. x += 1
2462
2463 - List comprehensions, e.g. [x**2 for x in range(10)]
2464
2465 - Extended import statement, e.g. import Module as Name
2466
2467 - Extended print statement, e.g. print >> file, "Hello"
2468
2469Other important changes:
2470
2471 - Optional collection of cyclical garbage
2472
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002473Python Enhancement Proposal (PEP)
2474---------------------------------
2475
2476PEP stands for Python Enhancement Proposal. A PEP is a design
2477document providing information to the Python community, or describing
2478a new feature for Python. The PEP should provide a concise technical
2479specification of the feature and a rationale for the feature.
2480
2481We intend PEPs to be the primary mechanisms for proposing new
2482features, for collecting community input on an issue, and for
2483documenting the design decisions that have gone into Python. The PEP
2484author is responsible for building consensus within the community and
2485documenting dissenting opinions.
2486
2487The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002488
2489Augmented Assignment
2490--------------------
2491
2492This must have been the most-requested feature of the past years!
2493Eleven new assignment operators were added:
2494
Guido van Rossume905e952000-09-05 12:42:46 +00002495 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002496
2497For example,
2498
2499 A += B
2500
2501is similar to
2502
2503 A = A + B
2504
2505except that A is evaluated only once (relevant when A is something
2506like dict[index].attr).
2507
2508However, if A is a mutable object, A may be modified in place. Thus,
2509if A is a number or a string, A += B has the same effect as A = A+B
2510(except A is only evaluated once); but if a is a list, A += B has the
2511same effect as A.extend(B)!
2512
2513Classes and built-in object types can override the new operators in
2514order to implement the in-place behavior; the not-in-place behavior is
2515used automatically as a fallback when an object doesn't implement the
2516in-place behavior. For classes, the method name is derived from the
2517method name for the corresponding not-in-place operator by inserting
2518an 'i' in front of the name, e.g. __iadd__ implements in-place
2519__add__.
2520
2521Augmented assignment was implemented by Thomas Wouters.
2522
2523
2524List Comprehensions
2525-------------------
2526
2527This is a flexible new notation for lists whose elements are computed
2528from another list (or lists). The simplest form is:
2529
2530 [<expression> for <variable> in <sequence>]
2531
Guido van Rossum56db0952000-09-06 23:34:25 +00002532For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002533This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002534
2535You can also add a condition:
2536
2537 [<expression> for <variable> in <sequence> if <condition>]
2538
2539For example, [w for w in words if w == w.lower()] would yield the list
2540of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002541than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002542
2543You can also have nested for loops and more than one 'if' clause. For
2544example, here's a function that flattens a sequence of sequences::
2545
2546 def flatten(seq):
2547 return [x for subseq in seq for x in subseq]
2548
2549 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2550
2551This prints
2552
2553 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2554
2555List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002556Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002557
2558
2559Extended Import Statement
2560-------------------------
2561
2562Many people have asked for a way to import a module under a different
2563name. This can be accomplished like this:
2564
2565 import foo
2566 bar = foo
2567 del foo
2568
2569but this common idiom gets old quickly. A simple extension of the
2570import statement now allows this to be written as follows:
2571
2572 import foo as bar
2573
2574There's also a variant for 'from ... import':
2575
2576 from foo import bar as spam
2577
2578This also works with packages; e.g. you can write this:
2579
2580 import test.regrtest as regrtest
2581
2582Note that 'as' is not a new keyword -- it is recognized only in this
2583context (this is only possible because the syntax for the import
2584statement doesn't involve expressions).
2585
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002586Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002587
2588
2589Extended Print Statement
2590------------------------
2591
2592Easily the most controversial new feature, this extension to the print
2593statement adds an option to make the output go to a different file
2594than the default sys.stdout.
2595
2596For example, to write an error message to sys.stderr, you can now
2597write:
2598
2599 print >> sys.stderr, "Error: bad dog!"
2600
2601As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002602evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002603
2604 print >> None, "Hello world"
2605
2606is equivalent to
2607
2608 print "Hello world"
2609
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002610Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002611
2612
2613Optional Collection of Cyclical Garbage
2614---------------------------------------
2615
2616Python is now equipped with a garbage collector that can hunt down
2617cyclical references between Python objects. It's no replacement for
2618reference counting; in fact, it depends on the reference counts being
2619correct, and decides that a set of objects belong to a cycle if all
2620their reference counts can be accounted for from their references to
2621each other. This devious scheme was first proposed by Eric Tiedemann,
2622and brought to implementation by Neil Schemenauer.
2623
2624There's a module "gc" that lets you control some parameters of the
2625garbage collection. There's also an option to the configure script
2626that lets you enable or disable the garbage collection. In 2.0b1,
2627it's on by default, so that we (hopefully) can collect decent user
2628experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002629performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002630off by default in the final 2.0 release.
2631
2632
2633Smaller Changes
2634---------------
2635
2636A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2637map(None, seq1, seq2, ...) when the sequences have the same length;
2638i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2639the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002640zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002641
2642sys.version_info is a tuple (major, minor, micro, level, serial).
2643
2644Dictionaries have an odd new method, setdefault(key, default).
2645dict.setdefault(key, default) returns dict[key] if it exists; if not,
2646it sets dict[key] to default and returns that value. Thus:
2647
2648 dict.setdefault(key, []).append(item)
2649
2650does the same work as this common idiom:
2651
2652 if not dict.has_key(key):
2653 dict[key] = []
2654 dict[key].append(item)
2655
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002656There are two new variants of SyntaxError that are raised for
2657indentation-related errors: IndentationError and TabError.
2658
2659Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2660escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002661
2662The limits on the size of expressions and file in Python source code
2663have been raised from 2**16 to 2**32. Previous versions of Python
2664were limited because the maximum argument size the Python VM accepted
2665was 2**16. This limited the size of object constructor expressions,
2666e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2667limit was raised thanks to a patch by Charles Waldman that effectively
2668fixes the problem. It is now much more likely that you will be
2669limited by available memory than by an arbitrary limit in Python.
2670
2671The interpreter's maximum recursion depth can be modified by Python
2672programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2673limit is the maximum number of recursive calls that can be made by
2674Python code. The limit exists to prevent infinite recursion from
2675overflowing the C stack and causing a core dump. The default value is
26761000. The maximum safe value for a particular platform can be found
2677by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002678
2679New Modules and Packages
2680------------------------
2681
2682atexit - for registering functions to be called when Python exits.
2683
2684imputil - Greg Stein's alternative API for writing custom import
2685hooks.
2686
2687pyexpat - an interface to the Expat XML parser, contributed by Paul
2688Prescod.
2689
2690xml - a new package with XML support code organized (so far) in three
2691subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2692would fill a volume. There's a special feature whereby a
2693user-installed package named _xmlplus overrides the standard
2694xmlpackage; this is intended to give the XML SIG a hook to distribute
2695backwards-compatible updates to the standard xml package.
2696
2697webbrowser - a platform-independent API to launch a web browser.
2698
2699
Guido van Rossume905e952000-09-05 12:42:46 +00002700Changed Modules
2701---------------
2702
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002703array -- new methods for array objects: count, extend, index, pop, and
2704remove
2705
2706binascii -- new functions b2a_hex and a2b_hex that convert between
2707binary data and its hex representation
2708
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002709calendar -- Many new functions that support features including control
2710over which day of the week is the first day, returning strings instead
2711of printing them. Also new symbolic constants for days of week,
2712e.g. MONDAY, ..., SUNDAY.
2713
2714cgi -- FieldStorage objects have a getvalue method that works like a
2715dictionary's get method and returns the value attribute of the object.
2716
2717ConfigParser -- The parser object has new methods has_option,
2718remove_section, remove_option, set, and write. They allow the module
2719to be used for writing config files as well as reading them.
2720
2721ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002722optionally support the RFC 959 REST command.
2723
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002724gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002725
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002726httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2727the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002728
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002729locale -- implement getdefaultlocale for Win32 and Macintosh
2730
2731marshal -- no longer dumps core when marshaling deeply nested or
2732recursive data structures
2733
2734os -- new functions isatty, seteuid, setegid, setreuid, setregid
2735
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002736os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2737support under Unix.
2738
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002739os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002740
2741os.path -- fix semantics of os.path.commonprefix
2742
2743smtplib -- support for sending very long messages
2744
2745socket -- new function getfqdn()
2746
2747readline -- new functions to read, write and truncate history files.
2748The readline section of the library reference manual contains an
2749example.
2750
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002751select -- add interface to poll system call
2752
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002753shutil -- new copyfileobj function
2754
2755SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2756HTTP server.
2757
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002758Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002759
2760urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002761e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002762
2763whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002764
2765
2766Obsolete Modules
2767----------------
2768
2769None. However note that 1.6 made a whole slew of modules obsolete:
2770stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2771poly, zmod, strop, util, whatsound.
2772
2773
2774Changed, New, Obsolete Tools
2775----------------------------
2776
Tim Peters8b092332000-09-05 20:15:25 +00002777None.
Guido van Rossume905e952000-09-05 12:42:46 +00002778
2779
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002780C-level Changes
2781---------------
2782
2783Several cleanup jobs were carried out throughout the source code.
2784
2785All C code was converted to ANSI C; we got rid of all uses of the
2786Py_PROTO() macro, which makes the header files a lot more readable.
2787
2788Most of the portability hacks were moved to a new header file,
2789pyport.h; several other new header files were added and some old
2790header files were removed, in an attempt to create a more rational set
2791of header files. (Few of these ever need to be included explicitly;
2792they are all included by Python.h.)
2793
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002794Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002795and Win64, especially for the new Intel Itanium processor. Mick also
2796added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002797
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002798The C APIs to return an object's size have been update to consistently
2799use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2800previous versions, the abstract interfaces used PyXXX_Length and the
2801concrete interfaces used PyXXX_Size. The old names,
2802e.g. PyObject_Length, are still available for backwards compatibility
2803at the API level, but are deprecated.
2804
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002805The PyOS_CheckStack function has been implemented on Windows by
2806Fredrik Lundh. It prevents Python from failing with a stack overflow
2807on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002808
2809The GC changes resulted in creation of two new slots on object,
2810tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002811the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002812
2813The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002814C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002815
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002816PyErr_Format has been updated to automatically calculate the size of
2817the buffer needed to hold the formatted result string. This change
2818prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002819
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002820New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002821
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002822PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2823that are the same as their non-Ex counterparts except they take an
2824extra flag argument that tells them to close the file when done.
2825
2826XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002827
Tim Peters8b092332000-09-05 20:15:25 +00002828
2829Windows Changes
2830---------------
2831
2832New popen2/popen3/peopen4 in os module (see Changed Modules above).
2833
2834os.popen is much more usable on Windows 95 and 98. See Microsoft
2835Knowledge Base article Q150956. The Win9x workaround described there
2836is implemented by the new w9xpopen.exe helper in the root of your
2837Python installation. Note that Python uses this internally; it is not
2838a standalone program.
2839
2840Administrator privileges are no longer required to install Python
2841on Windows NT or Windows 2000. If you have administrator privileges,
2842Python's registry info will be written under HKEY_LOCAL_MACHINE.
2843Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002844under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002845uses of Python, but will prevent some advanced uses from working
2846(for example, running a Python script as an NT service, or possibly
2847from CGI).
2848
2849[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2850installer; instead, it installs the needed Tcl/Tk files directly in the
2851Python directory. If you already have a Tcl/Tk installation, this
2852wastes some disk space (about 4 Megs) but avoids problems with
2853conflicting Tcl/Tk installations, and makes it much easier for Python
2854to ensure that Tcl/Tk can find all its files.
2855
2856[This was new in 1.6] The Windows installer now installs by default in
2857\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2858
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002859
2860Updates to the changes between 1.5.2 and 1.6
2861--------------------------------------------
2862
2863The 1.6 NEWS file can't be changed after the release is done, so here
2864is some late-breaking news:
2865
2866New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2867and changes to getlocale() and setlocale().
2868
2869The new module is now enabled per default.
2870
2871It is not true that the encodings codecs cannot be used for normal
2872strings: the string.encode() (which is also present on 8-bit strings
2873!) allows using them for 8-bit strings too, e.g. to convert files from
2874cp1252 (Windows) to latin-1 or vice-versa.
2875
2876Japanese codecs are available from Tamito KAJIYAMA:
2877http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2878
2879
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002880======================================================================