blob: c0f09ae09630b3dcafbbfb9146d6e8caf6e0ceff [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
Guido van Rossum49192142001-10-24 20:51:44 +000089- Updated RISCOS port by Dietmar Schwertberger.
90
Tim Peters84362bc2001-10-19 17:55:30 +000091Tests
92
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000093- Added a test script for the curses module. It isn't run automatically;
94 regrtest.py must be run with '-u curses' to enable it.
95
Tim Peters84362bc2001-10-19 17:55:30 +000096Windows
97
98
Tim Petersabf925f2001-09-28 21:53:42 +000099What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000100Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000101===========================
102
103Type/class unification and new-style classes
104
Guido van Rossum687ae002001-10-15 22:03:32 +0000105- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000106 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000107 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000108 remains: the __dict__ of a new-style class is a read-only proxy; you
109 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000110 __defined__ attribute of new-style types no longer exists, for lack
111 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000112 future a __cache__ may be resurrected with a similar function, if I
113 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000114
Tim Peters1c9ca872001-10-04 06:43:12 +0000115- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
116 always returned None, even when there was a class docstring).
117
118- doctest now finds and runs docstrings attached to new-style classes,
119 class methods, static methods, and properties.
120
Guido van Rossum9074ef62001-10-16 21:34:49 +0000121Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000122
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000123- A very subtle syntactical pitfall in list comprehensions was fixed.
124 For example: [a+b for a in 'abc', for b in 'def']. The comma in
125 this example is a mistake. Previously, this would silently let 'a'
126 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
127 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
128 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
129 Note that [a for a in <singleton>] is a convoluted way to say
130 [<singleton>] anyway, so it's not like any expressiveness is lost.
131
Guido van Rossum9074ef62001-10-16 21:34:49 +0000132- getattr(obj, name, default) now only catches AttributeError, as
133 documented, rather than returning the default value for all
134 exceptions (which could mask bugs in a __getattr__ hook, for
135 example).
136
Fred Drakecb7a6b52001-10-22 18:41:51 +0000137- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000138 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000139 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000140 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000141
Guido van Rossum1c486092001-10-19 02:05:35 +0000142- unicode(obj) now behaves more like str(obj), accepting arbitrary
143 objects, and calling a __unicode__ method if it exists.
144 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000145 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000146
Barry Warsawf6fb1712001-10-19 05:35:40 +0000147- isinstance() now allows any object as the first argument and a
148 class, a type or something with a __bases__ tuple attribute for the
149 second argument. The second argument may also be a tuple of a
150 class, type, or something with __bases__, in which case isinstance()
151 will return true if the first argument is an instance of any of the
152 things contained in the second argument tuple. E.g.
153
154 isinstance(x, (A, B))
155
156 returns true if x is an instance of A or B.
157
Guido van Rossum9074ef62001-10-16 21:34:49 +0000158Extension modules
159
160- thread.start_new_thread() now returns the thread ID (previously None).
161
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000162- binascii has now two quopri support functions, a2b_qp and b2a_qp.
163
Guido van Rossumc524d952001-10-19 01:31:59 +0000164- readline now supports setting the startup_hook and the
165 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000166
Guido van Rossumc524d952001-10-19 01:31:59 +0000167- os and posix supports chroot(), setgroups() and unsetenv() where
168 available. The stat(), fstat(), statvfs() and fstatvfs() functions
169 now return "pseudo-sequences" -- the various fields can now be
170 accessed as attributes (e.g. os.stat("/").st_mtime) but for
171 backwards compatibility they also behave as a fixed-length sequence.
172 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000173 attributes.
174
175- time: localtime(), gmtime() and strptime() now return a
176 pseudo-sequence similar to the os.stat() return value, with
177 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000178
Guido van Rossum9074ef62001-10-16 21:34:49 +0000179- Decompression objects in the zlib module now accept an optional
180 second parameter to decompress() that specifies the maximum amount
181 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000182
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000183- optional SSL support in the socket module now exports OpenSSL
184 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
185 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000186 automatically seed its PRNG. Also, the keyfile and certfile
187 arguments to socket.ssl() are now optional.
188
189- posixmodule (and by extension, the os module on POSIX platforms) now
190 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000191
Guido van Rossum9074ef62001-10-16 21:34:49 +0000192Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000193
Tim Peters7402f792001-10-02 03:53:41 +0000194- doctest now excludes functions and classes not defined by the module
195 being tested, thanks to Tim Hochberg.
196
Fred Drakecb7a6b52001-10-22 18:41:51 +0000197- HotShot, a new profiler implemented using a C-based callback, has
198 been added. This substantially reduces the overhead of profiling,
199 but it is still quite preliminary. Support modules and
200 documentation will be added in upcoming releases (before 2.2 final).
201
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000202- profile now produces correct output in situations where an exception
203 raised in Python is cleared by C code (e.g. hasattr()). This used
204 to cause wrong output, including spurious claims of recursive
205 functions and attribution of time spent to the wrong function.
206
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000207 The code and documentation for the derived OldProfile and HotProfile
208 profiling classes was removed. The code hasn't worked for years (if
209 you tried to use them, they raised exceptions). OldProfile
210 intended to reproduce the behavior of the profiler Python used more
211 than 7 years ago, and isn't interesting anymore. HotProfile intended
212 to provide a faster profiler (but producing less information), and
213 that's a worthy goal we intend to meet via a different approach (but
214 without losing information).
215
Tim Peterscce092d2001-10-09 05:31:56 +0000216- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000217 a much better system-specific calibration constant. The constant can
218 now be specified in an instance constructor, or as a Profile class or
219 instance variable, instead of by editing profile.py's source code.
220 Calibration must still be done manually (see the docs for the profile
221 module).
222
223 Note that Profile.calibrate() must be overriden by subclasses.
224 Improving the accuracy required exploiting detailed knowledge of
225 profiler internals; the earlier method abstracted away the details
226 and measured a simplified model instead, but consequently computed
227 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000228
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000229- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000230 which indicates whether output is intended for the header 'Q'
231 encoding.
232
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000233- The SocketServer.ThreadingMixIn class now closes the request after
234 finish_request() returns. (Not when it errors out though.)
235
Barry Warsawf6fb1712001-10-19 05:35:40 +0000236- The nntplib module's NNTP.body() method has grown a `file' argument
237 to allow saving the message body to a file.
238
239- The email package has added a class email.Parser.HeaderParser which
240 only parses headers and does not recurse into the message's body.
241 Also, the module/class MIMEAudio has been added for representing
242 audio data (contributed by Anthony Baxter).
243
244- ftplib should be able to handle files > 2GB.
245
246- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
247 ON, and OFF.
248
Fred Drakecb7a6b52001-10-22 18:41:51 +0000249- xml.dom.minidom NodeList objects now support the length attribute
250 and item() method as required by the DOM specifications.
251
Guido van Rossumed554f62001-10-02 23:15:37 +0000252Tools/Demos
253
254- Demo/dns was removed. It no longer serves any purpose; a package
255 derived from it is now maintained by Anthony Baxter, see
256 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000257
Barry Warsawf6fb1712001-10-19 05:35:40 +0000258- The freeze tool has been made more robust, and two new options have
259 been added: -X and -E.
260
Tim Petersabf925f2001-09-28 21:53:42 +0000261Build
262
Barry Warsawf6fb1712001-10-19 05:35:40 +0000263- configure will use CXX in LINKCC if CXX is used to build main() and
264 the system requires to link a C++ main using the C++ compiler.
265
Tim Petersabf925f2001-09-28 21:53:42 +0000266C API
267
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000268- The documentation for the tp_compare slot is updated to require that
269 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
270 not correct. This is not yet enforced but will be enforced in
271 Python 2.3; even later, we may use -2 to indicate errors and +2 for
272 "NotImplemented". Right now, -1 should be used for an error return.
273
Tim Petersd38b1c72001-09-30 05:09:37 +0000274- PyLong_AsLongLong() now accepts int (as well as long) arguments.
275 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
276 as long) arguments.
277
Guido van Rossum3c288632001-10-16 21:13:49 +0000278- PyThread_start_new_thread() now returns a long int giving the thread
279 ID, if one can be calculated; it returns -1 for error, 0 if no
280 thread ID is calculated (this is an incompatible change, but only
281 the thread module used this API). This code has only really been
282 tested on Linux and Windows; other platforms please beware (and
283 report any bugs or strange behavior).
284
Guido van Rossum1c486092001-10-19 02:05:35 +0000285- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
286 input.
287
Tim Petersabf925f2001-09-28 21:53:42 +0000288New platforms
289
290Tests
291
292Windows
293
Tim Peters04cf1d32001-10-09 22:39:40 +0000294- Installer: If you install IDLE, and don't disable file-extension
295 registration, a new "Edit with IDLE" context (right-click) menu entry
296 is created for .py and .pyw files.
297
Tim Peters1ce3cf72001-10-01 17:58:40 +0000298- The signal module now supports SIGBREAK on Windows, thanks to Steven
299 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
300 action remains to call Win32 ExitProcess(). This can be changed via
301 signal.signal(). For example:
302
303 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
304 # (SIGINT) behavior.
305 import signal
306 signal.signal(signal.SIGBREAK,
307 signal.default_int_handler)
308
309 try:
310 while 1:
311 pass
312 except KeyboardInterrupt:
313 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
314 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
315 # program without the possibility for any Python-level cleanup).
316 print "Clean exit"
317
Tim Petersabf925f2001-09-28 21:53:42 +0000318
Tim Petersb07352e2001-09-08 01:25:47 +0000319What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000320Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000321===========================
322
Guido van Rossum808eea72001-09-25 04:15:41 +0000323Type/class unification and new-style classes
324
325- pydoc and inspect are now aware of new-style classes;
326 e.g. help(list) at the interactive prompt now shows proper
327 documentation for all operations on list objects.
328
329- Applications using Jim Fulton's ExtensionClass module can now safely
330 be used with Python 2.2. In particular, Zope 2.4.1 now works with
331 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
332 examples also work again. It is hoped that Gtk and Boost also work
333 with 2.2a4 and beyond. (If you can confirm this, please write
334 webmaster@python.org; if there are still problems, please open a bug
335 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000336
Tim Peters66c1a522001-09-24 21:17:50 +0000337- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
338 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
339 in the constructed property object. fget, fset and fdel weren't
340 discoverable from Python in 2.2a3. __doc__ is new, and allows to
341 associate a docstring with a property.
342
Guido van Rossum808eea72001-09-25 04:15:41 +0000343- Comparison overloading is now more completely implemented. For
344 example, a str subclass instance can properly be compared to a str
345 instance, and it can properly overload comparison. Ditto for most
346 other built-in object types.
347
348- The repr() of new-style classes has changed; instead of <type
349 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
350 *except* for built-in types, which are still rendered as <type
351 'Foo'> (to avoid upsetting existing code that might parse or
352 otherwise rely on repr() of certain type objects).
353
354- The repr() of new-style objects is now always <Foo object at XXX>;
355 previously, it was sometimes <Foo instance at XXX>.
356
357- For new-style classes, what was previously called __getattr__ is now
358 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000359 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000360 one in classic classes is defined which is called only if regular
361 attribute access raises AttributeError; to catch *all* attribute
362 access, you can use __getattribute__ (for new-style classes). If
363 both are defined, __getattribute__ is called first, and if it raises
364 AttributeError, __getattr__ is called.
365
366- The __class__ attribute of new-style objects can be assigned to.
367 The new class must have the same C-level object layout as the old
368 class.
369
370- The builtin file type can be subclassed now. In the usual pattern,
371 "file" is the name of the builtin type, and file() is a new builtin
372 constructor, with the same signature as the builtin open() function.
373 file() is now the preferred way to open a file.
374
375- Previously, __new__ would only see sequential arguments passed to
376 the type in a constructor call; __init__ would see both sequential
377 and keyword arguments. This made no sense whatsoever any more, so
378 now both __new__ and __init__ see all arguments.
379
380- Previously, hash() applied to an instance of a subclass of str or
381 unicode always returned 0. This has been repaired.
382
383- Previously, an operation on an instance of a subclass of an
384 immutable type (int, long, float, complex, tuple, str, unicode),
385 where the subtype didn't override the operation (and so the
386 operation was handled by the builtin type), could return that
387 instance instead a value of the base type. For example, if s was of
388 a str sublass type, s[:] returned s as-is. Now it returns a str
389 with the same value as s.
390
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000391- Provisional support for pickling new-style objects has been added.
392
Guido van Rossum808eea72001-09-25 04:15:41 +0000393Core
394
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000395- file.writelines() now accepts any iterable object producing strings.
396
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000397- PyUnicode_FromEncodedObject() now works very much like
398 PyObject_Str(obj) in that it tries to use __str__/tp_str
399 on the object if the object is not a string or buffer. This
400 makes unicode() behave like str() when applied to non-string/buffer
401 objects.
402
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000403- PyFile_WriteObject now passes Unicode objects to the file's write
404 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000405 of a print statement must support Unicode objects, i.e. they must
406 at least convert them into ASCII strings.
407
Guido van Rossum624c8af2001-09-18 15:21:04 +0000408- Thread scheduling on Solaris should be improved; it is no longer
409 necessary to insert a small sleep at the start of a thread in order
410 to let other runnable threads be scheduled.
411
Tim Petersb07352e2001-09-08 01:25:47 +0000412Library
413
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000414- StringIO.StringIO instances and cStringIO.StringIO instances support
415 read character buffer compatible objects for their .write() methods.
416 These objects are converted to strings and then handled as such
417 by the instances.
418
Barry Warsaw2f600732001-09-24 04:28:10 +0000419- The "email" package has been added. This is basically a port of the
420 mimelib package <http://sf.net/projects/mimelib> with API changes
421 and some implementations updated to use iterators and generators.
422
Tim Peters8a9c2842001-09-22 21:30:22 +0000423- difflib.ndiff() and difflib.Differ.compare() are generators now. This
424 restores the ability of Tools/scripts/ndiff.py to start producing output
425 before the entire comparison is complete.
426
Barry Warsaw58b072d2001-09-22 04:44:21 +0000427- StringIO.StringIO instances and cStringIO.StringIO instances support
428 iteration just like file objects (i.e. their .readline() method is
429 called for each iteration until it returns an empty string).
430
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000431- The codecs module has grown four new helper APIs to access
432 builtin codecs: getencoder(), getdecoder(), getreader(),
433 getwriter().
434
Guido van Rossum624c8af2001-09-18 15:21:04 +0000435- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
436 simplifies writing XML RPC servers.
437
Barry Warsaw647d5e82001-09-28 17:01:02 +0000438- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000439 after interpretation of symbolic links. On non-Unix systems, this
440 is an alias for os.path.abspath().
441
Tim Peters16a77ad2001-09-08 04:00:12 +0000442- operator.indexOf() (PySequence_Index() in the C API) now works with any
443 iterable object.
444
Guido van Rossum624c8af2001-09-18 15:21:04 +0000445- smtplib now supports various authentication and security features of
446 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000447
Guido van Rossum624c8af2001-09-18 15:21:04 +0000448- hmac: a new module implementing keyed hashing for message
449 authentication.
450
451- mimetypes now recognizes more extensions and file types. At the
452 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000453
Guido van Rossum624c8af2001-09-18 15:21:04 +0000454- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000455 Python 2.2 bytecode generation. It has also been promoted from a
456 Tool to a standard library package. (Tools/compiler still exists as
457 a sample driver.)
458
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000459Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000460
Tim Petersb07352e2001-09-08 01:25:47 +0000461Build
462
Guido van Rossum624c8af2001-09-18 15:21:04 +0000463- Large file support (LFS) is now automatic when the platform supports
464 it; no more manual configuration tweaks are needed. On Linux, at
465 least, it's possible to have a system whose C library supports large
466 files but whose kernel doesn't; in this case, large file support is
467 still enabled but doesn't do you any good unless you upgrade your
468 kernel or share your Python executable with another system whose
469 kernel has large file support.
470
471- The configure script now supplies plausible defaults in a
472 cross-compilation environment. This doesn't mean that the supplied
473 values are always correct, or that cross-compilation now works
474 flawlessly -- but it's a first step (and it shuts up most of
475 autoconf's warnings about AC_TRY_RUN).
476
477- The Unix build is now a bit less chatty, courtesy of the parser
478 generator. The build is completely silent (except for errors) when
479 using "make -s", thanks to a -q option to setup.py.
480
Tim Petersb07352e2001-09-08 01:25:47 +0000481C API
482
Guido van Rossum624c8af2001-09-18 15:21:04 +0000483- The "structmember" API now supports some new flag bits to deny read
484 and/or write access to attributes in restricted execution mode.
485
Tim Petersb07352e2001-09-08 01:25:47 +0000486New platforms
487
Guido van Rossum624c8af2001-09-18 15:21:04 +0000488- Compaq's iPAQ handheld, running the "familiar" Linux distribution
489 (http://familiar.handhelds.org).
490
Tim Petersb07352e2001-09-08 01:25:47 +0000491Tests
492
Tim Peters8a9c2842001-09-22 21:30:22 +0000493- The "classic" standard tests, which work by comparing stdout to
494 an expected-output file under Lib/test/output/, no longer stop at
495 the first mismatch. Instead the test is run to completion, and a
496 variant of ndiff-style comparison is used to report all differences.
497 This is much easier to understand than the previous style of reporting.
498
499- The unittest-based standard tests now use regrtest's test_main()
500 convention, instead of running as a side-effect of merely being
501 imported. This allows these tests to be run in more natural and
502 flexible ways as unittests, outside the regrtest framework.
503
504- regrtest.py is much better integrated with unittest and doctest now,
505 especially in regard to reporting errors.
506
Tim Petersb07352e2001-09-08 01:25:47 +0000507Windows
508
Guido van Rossum624c8af2001-09-18 15:21:04 +0000509- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000510 that support it (NTFS under Windows 2000). See "What's New in
511 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000512
Tim Petersb07352e2001-09-08 01:25:47 +0000513
Tim Petersedc99312001-08-22 21:36:50 +0000514What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000515Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000516===========================
517
518Core
519
Tim Peters9fffa3e2001-09-04 05:14:19 +0000520- Conversion of long to float now raises OverflowError if the long is too
521 big to represent as a C double.
522
Tim Peters32f453e2001-09-03 08:35:41 +0000523- The 3-argument builtin pow() no longer allows a third non-None argument
524 if either of the first two arguments is a float, or if both are of
525 integer types and the second argument is negative (in which latter case
526 the arguments are converted to float, so this is really the same
527 restriction).
528
Tim Peters5d2b77c2001-09-03 05:47:38 +0000529- The builtin dir() now returns more information, and sometimes much
530 more, generally naming all attributes of an object, and all attributes
531 reachable from the object via its class, and from its class's base
532 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
533 an empty list. In 2.2a3,
534
535 >>> dir([])
536 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
537 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
538 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
539 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
540 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
541 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
542 'reverse', 'sort']
543
544 dir(module) continues to return only the module's attributes, though.
545
Tim Petersbdee63f2001-09-02 03:40:59 +0000546- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000547 than raising OverflowError. This is a partial implementation of PEP
548 237. You can use -Wdefault::OverflowWarning to enable a warning for
549 this situation, and -Werror::OverflowWarning to revert to the old
550 OverflowError exception.
551
Guido van Rossum61c345f2001-09-04 03:26:15 +0000552- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000553 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000554 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
555 -Qold, meaning the / operator has its classic meaning and no
556 warnings are issued. Using -Qwarn issues a run-time warning about
557 all uses of classic division for int and long arguments; -Qwarnall
558 also warns about classic division for float and complex arguments
559 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
560 new division by default, but only in the __main__ module. You can
561 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
562 __main__ module new division, and warns about classic division
563 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000564
Tim Petersbdee63f2001-09-02 03:40:59 +0000565- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000566 long, float, str, unicode, and tuple. (The types complex, list and
567 dictionary can also be subclassed; this was introduced earlier.)
568 Note that restrictions apply when subclassing immutable built-in
569 types: you can only affect the value of the instance by overloading
570 __new__. You can add mutable attributes, and the subclass instances
571 will have a __dict__ attribute, but you cannot change the "value"
572 (as implemented by the base class) of an immutable subclass instance
573 once it is created.
574
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000575- The dictionary constructor now takes an optional argument, a
576 mapping-like object, and initializes the dictionary from its
577 (key, value) pairs.
578
Tim Petersbdee63f2001-09-02 03:40:59 +0000579- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000580 "cooperative super calls" in a multiple inheritance setting. For an
581 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
582
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000583- A new built-in type, property, has been added. This enables the
584 creation of "properties". These are attributes implemented by
585 getter and setter functions (or only one of these for read-only or
586 write-only attributes), without the need to override __getattr__.
587 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000588
Tim Petersbdee63f2001-09-02 03:40:59 +0000589- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000590 liberalized, to allow leading zeroes. Examples of literals now
591 legal that were SyntaxErrors before:
592
593 00.0 0e3 0100j 07.5 00000000000000000008.
594
Tim Petersbdee63f2001-09-02 03:40:59 +0000595- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000596 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
597
Tim Petersedc99312001-08-22 21:36:50 +0000598Library
599
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000600- telnetlib includes symbolic names for the options, and support for
601 setting an option negotiation callback.
602
Tim Petersa40c7932001-09-05 22:36:56 +0000603- The new C standard no longer requires that math libraries set errno to
604 ERANGE on overflow. For platform libraries that exploit this new
605 freedom, Python's overflow-checking was wholly broken. A new overflow-
606 checking scheme attempts to repair that, but may not be reliable on all
607 platforms (C doesn't seem to provide anything both useful and portable
608 in this area anymore).
609
Martin v. Löwis44f86962001-09-05 13:44:54 +0000610- Asynchronous timeout actions are available through the new class
611 threading.Timer.
612
Tim Peters78526162001-09-05 00:53:45 +0000613- math.log and math.log10 now return sensible results for even huge
614 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
615
Tim Petersbdee63f2001-09-02 03:40:59 +0000616- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000617 currently held. See the docs for the imp module.
618
Tim Petersbdee63f2001-09-02 03:40:59 +0000619- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000620 dumps containing ints written on platforms where Python ints are 8 bytes.
621 When read on a box where Python ints are 4 bytes, such values are
622 converted to Python longs.
623
Tim Petersbdee63f2001-09-02 03:40:59 +0000624- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000625 code objects is no longer allowed. This plugs a security hole.
626
Steve Purcell6091cd62001-09-06 16:05:17 +0000627- unittest.TestResult instances no longer store references to tracebacks
628 generated by test failures. This prevents unexpected dangling references
629 to objects that should be garbage collected between tests.
630
Tim Petersedc99312001-08-22 21:36:50 +0000631Tools
632
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000633- Tools/scripts/fixdiv.py has been added which can be used to fix
634 division operators as per PEP 238.
635
Tim Petersedc99312001-08-22 21:36:50 +0000636Build
637
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000638- If you are an adventurous person using Mac OS X you may want to look at
639 Mac/OSX. There is a Makefile there that will build Python as a real Mac
640 application, which can be used for experimenting with Carbon or Cocoa.
641 Discussion of this on pythonmac-sig, please.
642
Tim Peters7eea37e2001-09-04 22:08:56 +0000643C API
644
645- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000646
Tim Peters9fffa3e2001-09-04 05:14:19 +0000647- Note that PyLong_AsDouble can fail! This has always been true, but no
648 callers checked for it. It's more likely to fail now, because overflow
649 errors are properly detected now. The proper way to check:
650
651 double x = PyLong_AsDouble(some_long_object);
652 if (x == -1.0 && PyErr_Occurred()) {
653 /* The conversion failed. */
654 }
655
Tim Petersbdee63f2001-09-02 03:40:59 +0000656- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000657 compile but will not participate in GC. To upgrade an extension
658 module:
659
660 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000661
Neil Schemenauer4042c692001-08-30 15:38:01 +0000662 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
663 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000664
Neil Schemenauer4042c692001-08-30 15:38:01 +0000665 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
666 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000667
Neil Schemenauer4042c692001-08-30 15:38:01 +0000668 - remove PyGC_HEAD_SIZE from object size calculations
669
670 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
671
Tim Petersbdee63f2001-09-02 03:40:59 +0000672- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000673 These can be used safely to construct string objects from a
674 sprintf-style format string (similar to the format string supported
675 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000676
Tim Petersedc99312001-08-22 21:36:50 +0000677New platforms
678
Tim Petersb7da0902001-09-02 23:01:43 +0000679- Stephen Hansen contributed patches sufficient to get a clean compile
680 under Borland C (Windows), but he reports problems running it and ran
681 out of time to complete the port. Volunteers? Expect a MemoryError
682 when importing the types module; this is probably shallow, and
683 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000684
Tim Petersedc99312001-08-22 21:36:50 +0000685Tests
686
687Windows
688
Tim Peters6e13a562001-09-06 00:32:15 +0000689- Large file support is now enabled on Win32 platforms as well as on
690 Win64. This means that, for example, you can use f.tell() and f.seek()
691 to manipulate files larger than 2 gigabytes (provided you have enough
692 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000693 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
694 filesize limit, and large file support makes no difference there.
695 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
696 NTFS has no practical limit on file size, and files of any size can be
697 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000698
Tim Petersbdee63f2001-09-02 03:40:59 +0000699- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000700 points to command.com (patch from Brian Quinlan).
701
Tim Petersedc99312001-08-22 21:36:50 +0000702
Tim Peters20f51a72001-07-21 02:31:40 +0000703What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000704Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000705===========================
706
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000707Build
708
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000709- Tim Peters developed a brand new Windows installer using Wise 8.1,
710 generously donated to us by Wise Solutions.
711
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000712- configure supports a new option --enable-unicode, with the values
713 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
714 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000715
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000716- A new configure option --enable-framework builds a Mac OS X framework,
717 which "make frameworkinstall" will install. This provides a starting
718 point for more mac-like functionality, join pythonmac-sig@python.org
719 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000720
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000721- The NeXT platform is no longer supported.
722
723- The `new' module is now statically linked.
724
Tim Peters0afb6092001-08-15 06:06:44 +0000725Tools
726
727- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000728 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000729 the module docstring for details.
730
Tim Peters20f51a72001-07-21 02:31:40 +0000731Tests
732
Tim Peters5e824c32001-08-12 22:25:01 +0000733- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000734 platforms, allowing to give clearer test result output. regrtest
735 also has optional --use/-u switch to run normally disabled tests
736 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000737
Tim Peters20f51a72001-07-21 02:31:40 +0000738- Several new tests in the standard test suite, with special thanks to
739 Nick Mathewson.
740
741Core
742
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000743- The floor division operator // has been added as outlined in PEP
744 238. The / operator still provides classic division (and will until
745 Python 3.0) unless "from __future__ import division" is included, in
746 which case the / operator will provide true division. The operator
747 module provides truediv() and floordiv() functions. Augmented
748 assignment variants are included, as are the equivalent overloadable
749 methods and C API methods. See the PEP for a full discussion:
750 <http://python.sf.net/peps/pep-0238.html>
751
Tim Peters6cd6a822001-08-17 22:11:27 +0000752- Future statements are now effective in simulated interactive shells
753 (like IDLE). This should "just work" by magic, but read Michael
754 Hudson's "Future statements in simulated shells" PEP 264 for full
755 details: <http://python.sf.net/peps/pep-0264.html>.
756
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000757- The type/class unification (PEP 252-253) was integrated into the
758 trunk and is not so tentative any more (the exact specification of
759 some features is still tentative). A lot of work has done on fixing
760 bugs and adding robustness and features (performance still has to
761 come a long way).
762
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000763- Warnings about a mismatch in the Python API during extension import
764 now use the Python warning framework (which makes it possible to
765 write filters for these warnings).
766
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000767- A function's __dict__ (aka func_dict) will now always be a
768 dictionary. It used to be possible to delete it or set it to None,
769 but now both actions raise TypeErrors. It is still legal to set it
770 to a dictionary object. Getting func.__dict__ before any attributes
771 have been assigned now returns an empty dictionary instead of None.
772
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000773- A new command line option, -E, was added which disables the use of
774 all environment variables, or at least those that are specifically
775 significant to Python. Usually those have a name starting with
776 "PYTHON". This was used to fix a problem where the tests fail if
777 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
778 older distribution.
779
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000780Library
781
Tim Peters5e824c32001-08-12 22:25:01 +0000782- New class Differ and new functions ndiff() and restore() in difflib.py.
783 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000784 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000785
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000786- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
787 value using the minimal quoting required for the value; more
788 reliable than using xml.sax.saxutils.escape() for attribute values.
789
790- Readline completion support for cmd.Cmd was added.
791
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000792- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
793
794- Added function threading.BoundedSemaphore()
795
796- Added Ka-Ping Yee's cgitb.py module.
797
798- The `new' module now exposes the CO_xxx flags.
799
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000800New platforms
801
802C API
803
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000804- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
805 which provide a cross-platform implementations for the
806 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
807 the standard sprintf() and vsprintf() C lib APIs, these versions
808 apply bounds checking on the used buffer which enhances protection
809 against buffer overruns.
810
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000811- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000812 and extensions using different Unicode widths is rendered next to
813 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000814 will result in an ImportError. Unicode extensions writers must make
815 sure to check the Unicode width compatibility in their extensions by
816 using at least one of the mangled Unicode APIs in the extension.
817
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000818- Two new flags METH_NOARGS and METH_O are available in method definition
819 tables to simplify implementation of methods with no arguments and a
820 single untyped argument. Calling such methods is more efficient than
821 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
822 deprecated.
823
Tim Petersc1731372001-08-04 08:12:36 +0000824Windows
825
826- "import module" now compiles module.pyw if it exists and nothing else
827 relevant is found.
828
Tim Peters20f51a72001-07-21 02:31:40 +0000829
Guido van Rossum55a78992001-07-17 17:22:32 +0000830What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +0000831Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +0000832===========================
833
834Core
Tim Petersa814db52001-05-14 07:05:58 +0000835
Tim Peters6d6c1a32001-08-02 04:15:00 +0000836- TENTATIVELY, a large amount of code implementing much of what's
837 described in PEP 252 (Making Types Look More Like Classes) and PEP
838 253 (Subtyping Built-in Types) was added. This will be released
839 with Python 2.2a1. Documentation will be provided separately
840 through http://www.python.org/2.2/. The purpose of releasing this
841 with Python 2.2a1 is to test backwards compatibility. It is
842 possible, though not likely, that a decision is made not to release
843 this code as part of 2.2 final, if any serious backwards
844 incompapatibilities are found during alpha testing that cannot be
845 repaired.
846
Guido van Rossum55a78992001-07-17 17:22:32 +0000847- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000848 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000849 more 'yield' statements. See PEP 255. Since this adds a new
850 keyword to the language, this feature must be enabled by including a
851 future statement: "from __future__ import generators" (see PEP 236).
852 Generators will become a standard feature in a future release
853 (probably 2.3). Without this future statement, 'yield' remains an
854 ordinary identifier, but a warning is issued each time it is used.
855 (These warnings currently don't conform to the warnings framework of
856 PEP 230; we intend to fix this in 2.2a2.)
857
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000858- The UTF-16 codec was modified to be more RFC compliant. It will now
859 only remove BOM characters at the start of the string and then
860 only if running in native mode (UTF-16-LE and -BE won't remove a
861 leading BMO character).
862
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000863- Strings now have a new method .decode() to complement the already
864 existing .encode() method. These two methods provide direct access
865 to the corresponding decoders and encoders of the registered codecs.
866
867 To enhance the usability of the .encode() method, the special
868 casing of Unicode object return values was dropped (Unicode objects
869 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000870
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000871 Both methods will now return whatever the codec in charge of the
872 requested encoding returns as object, e.g. Unicode codecs will
873 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
874 will return u"äöü"). This enables codec writer to create codecs
875 for various simple to use conversions.
876
877 New codecs were added to demonstrate these new features (the .encode()
878 and .decode() columns indicate the type of the returned objects):
879
880 Name | .encode() | .decode() | Description
881 ----------------------------------------------------------------------
882 uu | string | string | UU codec (e.g. for email)
883 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000884 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000885 zlib | string | string | zlib compression
886 hex | string | string | 2-byte hex codec
887 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
888
Mark Hammond2a0af792001-05-14 03:09:36 +0000889- Some operating systems now support the concept of a default Unicode
890 encoding for file system operations. Notably, Windows supports 'mbcs'
891 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000892 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000893 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000894
895 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000896 functions that return filenames (such as os.listdir()) to return Python
897 string objects pre-encoded using the default file system encoding for
898 the platform. As this encoding is likely to be different from Python's
899 default encoding, converting this name to a Unicode object before passing
900 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000901 would attempt to use its default encoding (generally ASCII) rather than
902 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000903
Tim Petersa814db52001-05-14 07:05:58 +0000904 In general, this change simply removes surprises when working with
905 Unicode and the file system, making these operations work as you expect,
906 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000907 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000908
Tim Peters61dff2b2001-05-08 15:43:37 +0000909- Float (and complex) literals in source code were evaluated to full
910 precision only when running from a .py file; the same code loaded from a
911 .pyc (or .pyo) file could suffer numeric differences starting at about the
912 12th significant decimal digit. For example, on a machine with IEEE-754
913 floating arithmetic,
914
915 x = 9007199254740992.0
916 print long(x)
917
918 printed 9007199254740992 if run directly from .py, but 9007199254740000
919 if from a compiled (.pyc or .pyo) file. This was due to marshal using
920 str(float) instead of repr(float) when building code objects. marshal
921 now uses repr(float) instead, which should reproduce floats to full
922 machine precision (assuming the platform C float<->string I/O conversion
923 functions are of good quality).
924
925 This may cause floating-point results to change in some cases, and
926 usually for the better, but may also cause numerically unstable
927 algorithms to break.
928
Tim Peters2f228e72001-05-13 00:19:31 +0000929- The implementation of dicts suffers fewer collisions, which has speed
930 benefits. However, the order in which dict entries appear in dict.keys(),
931 dict.values() and dict.items() may differ from previous releases for a
932 given dict. Nothing is defined about this order, so no program should
933 rely on it. Nevertheless, it's easy to write test cases that rely on the
934 order by accident, typically because of printing the str() or repr() of a
935 dict to an "expected results" file. See Lib/test/test_support.py's new
936 sortdict(dict) function for a simple way to display a dict in sorted
937 order.
938
Tim Peters7a3bfc32001-06-12 01:22:22 +0000939- Many other small changes to dicts were made, resulting in faster
940 operation along the most common code paths.
941
Guido van Rossum10315822001-05-01 20:54:30 +0000942- Dictionary objects now support the "in" operator: "x in dict" means
943 the same as dict.has_key(x).
944
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000945- The update() method of dictionaries now accepts generic mapping
946 objects. Specifically the argument object must support the .keys()
947 and __getitem__() methods. This allows you to say, for example,
948 {}.update(UserDict())
949
Guido van Rossum10315822001-05-01 20:54:30 +0000950- Iterators were added; this is a generalized way of providing values
951 to a for loop. See PEP 234. There's a new built-in function iter()
952 to return an iterator. There's a new protocol to get the next value
953 from an iterator using the next() method (in Python) or the
954 tp_iternext slot (in C). There's a new protocol to get iterators
955 using the __iter__() method (in Python) or the tp_iter slot (in C).
956 Iterating (i.e. a for loop) over a dictionary generates its keys.
957 Iterating over a file generates its lines.
958
Tim Petersf553f892001-05-01 20:45:31 +0000959- The following functions were generalized to work nicely with iterator
960 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000961 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000962 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
963 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000964 join() method of strings
965 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000966 'x in y' and 'x not in y' (PySequence_Contains() in C API)
967 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000968 right-hand side of assignment statements with multiple targets, such as
969 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000970
Tim Petersd85e1022001-05-11 21:51:48 +0000971- Accessing module attributes is significantly faster (for example,
972 random.random or os.path or yourPythonModule.yourAttribute).
973
Tim Peterse63415e2001-05-08 04:38:29 +0000974- Comparing dictionary objects via == and != is faster, and now works even
975 if the keys and values don't support comparisons other than ==.
976
Tim Peters95bf9392001-05-10 08:32:44 +0000977- Comparing dictionaries in ways other than == and != is slower: there were
978 insecurities in the dict comparison implementation that could cause Python
979 to crash if the element comparison routines for the dict keys and/or
980 values mutated the dicts. Making the code bulletproof slowed it down.
981
Tim Peterseb28ef22001-06-02 05:27:19 +0000982- Collisions in dicts are resolved via a new approach, which can help
983 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000984 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000985 faster now. Thanks to Christian Tismer for pointing out the cause and
986 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000987
Tim Peters52e155e2001-06-16 05:42:57 +0000988- repr() is much faster for large containers (dict, list, tuple).
989
990
Tim Petersa814db52001-05-14 07:05:58 +0000991Library
992
Fred Drake960fdf92001-07-20 18:38:26 +0000993- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
994 were added to the string module. These a locale-indenpendent
995 constants, unlike letters, lowercase, and uppercase. These are now
996 use in appropriate locations in the standard library.
997
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000998- The flags used in dlopen calls can now be configured using
999 sys.setdlopenflags and queried using sys.getdlopenflags.
1000
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001001- Fredrik Lundh's xmlrpclib is now a standard library module. This
1002 provides full client-side XML-RPC support. In addition,
1003 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1004 one asyncore-based). Thanks to Eric Raymond for the documentation.
1005
Guido van Rossum643d3912001-07-05 14:46:25 +00001006- The xrange() object is simplified: it no longer supports slicing,
1007 repetition, comparisons, efficient 'in' checking, the tolist()
1008 method, or the start, stop and step attributes. See PEP 260.
1009
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001010- A new function fnmatch.filter to filter lists of file names was added.
1011
Barry Warsawffd674d2001-05-22 16:00:10 +00001012- calendar.py uses month and day names based on the current locale.
1013
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001014- strop is now *really* obsolete (this was announced before with 1.6),
1015 and issues DeprecationWarning when used (except for the four items
1016 that are still imported into string.py).
1017
Tim Petersa814db52001-05-14 07:05:58 +00001018- Cookie.py now sorts key+value pairs by key in output strings.
1019
1020- pprint.isrecursive(object) didn't correctly identify recursive objects.
1021 Now it does.
1022
Tim Peters95b3f782001-05-14 18:39:41 +00001023- pprint functions now much faster for large containers (tuple, list, dict).
1024
Tim Peters7b9542a2001-06-10 23:40:19 +00001025- New 'q' and 'Q' format codes in the struct module, corresponding to C
1026 types "long long" and "unsigned long long" (on Windows, __int64). In
1027 native mode, these can be used only when the platform C compiler supports
1028 these types (when HAVE_LONG_LONG is #define'd by the Python config
1029 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001030 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1031 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001032
Guido van Rossum83213cc2001-06-12 16:48:52 +00001033- The site module installs a new built-in function 'help' that invokes
1034 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1035 it displays a message reminding the user to use 'help()' or
1036 'help(object)'.
1037
Tim Petersa814db52001-05-14 07:05:58 +00001038Tests
1039
1040- New test_mutants.py runs dict comparisons where the key and value
1041 comparison operators mutute the dicts randomly during comparison. This
1042 rapidly causes Python to crash under earlier releases (not for the faint
1043 of heart: it can also cause Win9x to freeze or reboot!).
1044
1045- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001046 pprint.isreadable() return sensible results. Also verifies that simple
1047 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001048
Tim Peters4324aa32001-05-28 22:30:08 +00001049C API
1050
1051- Removed the unused last_is_sticky argument from the internal
1052 _PyTuple_Resize(). If this affects you, you were cheating.
1053
1054
Guido van Rossum55a78992001-07-17 17:22:32 +00001055======================================================================
1056
1057
Guido van Rossumffe13be2001-04-16 18:46:45 +00001058What's New in Python 2.1 (final)?
1059=================================
1060
1061We only changed a few things since the last release candidate, all in
1062Python library code:
1063
1064- A bug in the locale module was fixed that affected locales which
1065 define no grouping for numeric formatting.
1066
1067- A few bugs in the weakref module's implementations of weak
1068 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1069 and the test suite was updated to check for these bugs.
1070
1071- An old bug in the os.path.walk() function (introduced in Python
1072 2.0!) was fixed: a non-existent file would cause an exception
1073 instead of being ignored.
1074
1075- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1076 PyChecker.
1077
1078
Guido van Rossum5b08f132001-04-16 02:05:23 +00001079What's New in Python 2.1c2?
1080===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001081
Guido van Rossum5b08f132001-04-16 02:05:23 +00001082A flurry of small changes, and one showstopper fixed in the nick of
1083time made it necessary to release another release candidate. The list
1084here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001085
Guido van Rossum5b08f132001-04-16 02:05:23 +00001086Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001087
Guido van Rossum5b08f132001-04-16 02:05:23 +00001088- Tim discovered a nasty bug in the dictionary code, caused by
1089 PyDict_Next() calling dict_resize(), and the GC code's use of
1090 PyDict_Next() violating an assumption in dict_items(). This was
1091 fixed with considerable amounts of band-aid, but the net effect is a
1092 saner and more robust implementation.
1093
1094- Made a bunch of symbols static that were accidentally global.
1095
1096Build and Ports
1097
1098- The setup.py script didn't check for a new enough version of zlib
1099 (1.1.3 is needed). Now it does.
1100
1101- Changed "make clean" target to also remove shared libraries.
1102
1103- Added a more general warning about the SGI Irix optimizer to README.
1104
1105Library
1106
1107- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1108 omitted the slash between host and file.html.
1109
1110- The mailbox module's _Mailbox class contained a completely broken
1111 and undocumented seek() method. Ripped it out.
1112
1113- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1114 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1115
1116- Fixed a few last-minute bugs in unittest.
1117
1118Extensions
1119
1120- Reverted the patch to the OpenSSL code in socketmodule.c to support
1121 RAND_status() and the EGD, and the subsequent patch that tried to
1122 fix it for pre-0.9.5 versions; the problem with the patch is that on
1123 some systems it issues a warning whenever socket is imported, and
1124 that's unacceptable.
1125
1126Tests
1127
1128- Fixed the pickle tests to work with "import test.test_pickle".
1129
1130- Tweaked test_locale.py to actually run the test Windows.
1131
1132- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1133 not "wb" (which is not a valid mode at all).
1134
1135- Fix pstats browser crashes. Import readline if it exists to make
1136 the user interface nicer.
1137
1138- Add "import thread" to the top of test modules that import the
1139 threading module (test_asynchat and test_threadedtempfile). This
1140 prevents test failures caused by a broken threading module resulting
1141 from a previously caught failed import.
1142
1143- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1144 needed on some platforms (e.g. Solaris 8) when the tests are run
1145 twice in succession.
1146
1147- Skip rather than fail test_sunaudiodev if no audio device is found.
1148
1149
1150What's New in Python 2.1c1?
1151===========================
1152
1153This list was significantly updated when 2.1c2 was released; the 2.1c1
1154release didn't mention most changes that were actually part of 2.1c1:
1155
1156Legal
1157
1158- Copyright was assigned to the Python Software Foundation (PSF) and a
1159 PSF license (very similar to the CNRI license) was added.
1160
1161- The CNRI copyright notice was updated to include 2001.
1162
1163Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001164
Guido van Rossumc9932722001-04-12 02:31:27 +00001165- After a public outcry, assignment to __debug__ is no longer illegal;
1166 instead, a warning is issued. It will become illegal in 2.2.
1167
Guido van Rossum5b08f132001-04-16 02:05:23 +00001168- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1169 "%#x" now always prepends "0x", even if the value is zero.
1170
1171- Fixed some nits in the bytecode compiler.
1172
1173- Fixed core dumps when calling certain kinds of non-functions.
1174
1175- Fixed various core dumps caused by reference count bugs.
1176
1177Build and Ports
1178
1179- Use INSTALL_SCRIPT to install script files.
1180
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001181- New port: SCO Unixware 7, by Billy G. Allie.
1182
Guido van Rossum5b08f132001-04-16 02:05:23 +00001183- Updated RISCOS port.
1184
1185- Updated BeOS port and notes.
1186
1187- Various other porting problems resolved.
1188
1189Library
1190
1191- The TERMIOS and SOCKET modules are now truly obsolete and
1192 unnecessary. Their symbols are incorporated in the termios and
1193 socket modules.
1194
1195- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1196 better tests for pickling.
1197
1198- threading: make Condition.wait() robust against KeyboardInterrupt.
1199
1200- zipfile: add support to zipfile to support opening an archive
1201 represented by an open file rather than a file name. Fix bug where
1202 the archive was not properly closed. Fixed a bug in this bugfix
1203 where flush() was called for a read-only file.
1204
1205- imputil: added an uninstall() method to the ImportManager.
1206
1207- Canvas: fixed bugs in lower() and tkraise() methods.
1208
1209- SocketServer: API change (added overridable close_request() method)
1210 so that the TCP server can explicitly close the request.
1211
1212- pstats: Eric Raymond added a simple interactive statistics browser,
1213 invoked when the module is run as a script.
1214
1215- locale: fixed a problem in format().
1216
1217- webbrowser: made it work when the BROWSER environment variable has a
1218 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1219 KDE 2. Fixed some other nits.
1220
1221- unittest: changes to allow using a different exception than
1222 AssertionError, and added a few more function aliases. Some other
1223 small changes.
1224
1225- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1226
1227- asynchat: fixed a critical bug in asynchat that slipped through the
1228 2.1b2 release. Fixed another rare bug.
1229
1230- Fix some unqualified except: clauses (always a bad code example).
1231
1232XML
1233
1234- pyexpat: new API get_version_string().
1235
1236- Fixed some minidom bugs.
1237
1238Extensions
1239
1240- Fixed a core dump in _weakref. Removed the weakref.mapping()
1241 function (it adds nothing to the API).
1242
1243- Rationalized the use of header files in the readline module, to make
1244 it compile (albeit with some warnings) with the very recent readline
1245 4.2, without breaking for earlier versions.
1246
1247- Hopefully fixed a buffering problem in linuxaudiodev.
1248
1249- Attempted a fix to make the OpenSSL support in the socket module
1250 work again with pre-0.9.5 versions of OpenSSL.
1251
1252Tests
1253
1254- Added a test case for asynchat and asyncore.
1255
1256- Removed coupling between tests where one test failing could break
1257 another.
1258
1259Tools
1260
1261- Ping added an interactive help browser to pydoc, fixed some nits
1262 in the rest of the pydoc code, and added some features to his
1263 inspect module.
1264
1265- An updated python-mode.el version 4.1 which integrates Ken
1266 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1267 much nicer in XEmacs and Emacs. When stepping through your program
1268 with pdb, in either the shell window or the *Python* window, the
1269 source file and line will be tracked by an arrow. Very cool!
1270
1271- IDLE: syntax warnings in interactive mode are changed into errors.
1272
1273- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001274 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001275
1276- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001277
Barry Warsaw11e89c72001-04-11 20:37:57 +00001278
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001279What's New in Python 2.1 beta 2?
1280================================
1281
Guido van Rossum053ae352001-03-22 14:17:21 +00001282(Unlisted are many fixed bugs, more documentation, etc.)
1283
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001284Core language, builtins, and interpreter
1285
Guido van Rossum053ae352001-03-22 14:17:21 +00001286- The nested scopes work (enabled by "from __future__ import
1287 nested_scopes") is completed; in particular, the future now extends
1288 into code executed through exec, eval() and execfile(), and into the
1289 interactive interpreter.
1290
1291- When calling a base class method (e.g. BaseClass.__init__(self)),
1292 this is now allowed even if self is not strictly spoken a class
1293 instance (e.g. when using metaclasses or the Don Beaudry hook).
1294
1295- Slice objects are now comparable but not hashable; this prevents
1296 dict[:] from being accepted but meaningless.
1297
1298- Complex division is now calculated using less braindead algorithms.
1299 This doesn't change semantics except it's more likely to give useful
1300 results in extreme cases. Complex repr() now uses full precision
1301 like float repr().
1302
1303- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1304
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001305- It is illegal to assign to the name __debug__, which is set when the
1306 interpreter starts. It is effectively a compile-time constant.
1307
1308- A warning will be issued if a global statement for a variable
1309 follows a use or assignment of that variable.
1310
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001311Standard library
1312
Guido van Rossum053ae352001-03-22 14:17:21 +00001313- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1314 inspired by JUnit), is now part of the standard library. You now
1315 have a choice of two testing frameworks: unittest requires you to
1316 write testcases as separate code, doctest gathers them from
1317 docstrings. Both approaches have their advantages and
1318 disadvantages.
1319
1320- A new module Tix was added, which wraps the Tix extension library
1321 for Tk. With that module, it is not necessary to statically link
1322 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1323 require" command. See Demo/tix/.
1324
1325- tzparse.py is now obsolete.
1326
1327- In gzip.py, the seek() and tell() methods are removed -- they were
1328 non-functional anyway, and it's better if callers can test for their
1329 existence with hasattr().
1330
1331Python/C API
1332
1333- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1334 that's already in the dictionary during a PyDict_Next() iteration.
1335 This used to fail occasionally when a dictionary resize operation
1336 could be triggered that would rehash all the keys. All other
1337 modifications to the dictionary are still off-limits during a
1338 PyDict_Next() iteration!
1339
1340- New extended APIs related to passing compiler variables around.
1341
1342- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1343 implement isinstance() and issubclass().
1344
1345- Py_BuildValue() now has a "D" conversion to create a Python complex
1346 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001347
Fred Drake4e262a92001-03-22 18:26:47 +00001348- Extensions types which support weak references must now set the
1349 field allocated for the weak reference machinery to NULL themselves;
1350 this is done to avoid the cost of checking each object for having a
1351 weakly referencable type in PyObject_INIT(), since most types are
1352 not weakly referencable.
1353
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001354- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1355 free variables and cell variables to and from the frame's f_locals.
1356
1357- Variants of several functions defined in pythonrun.h have been added
1358 to support the nested_scopes future statement. The variants all end
1359 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1360 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1361 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001362 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001363
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001364Distutils
1365
1366- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1367 into the release tree.
1368
Tim Peters0e57abf2001-05-02 07:39:38 +00001369- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001370 (an uninstaller, more customization of the installer's display)
1371
1372- from Jack Jansen: added Mac-specific code to generate a dialog for
1373 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001374 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001375 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001376
1377- added 'platforms' and 'keywords' to the set of metadata that can be
1378 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001379
1380- applied patches from Jason Tishler to make the compiler class work with
1381 Cygwin.
1382
1383
Tim Peters2fe289a2001-03-01 22:19:38 +00001384What's New in Python 2.1 beta 1?
1385================================
Tim Petersd66595f2001-02-04 03:09:53 +00001386
1387Core language, builtins, and interpreter
1388
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001389- Following an outcry from the community about the amount of code
1390 broken by the nested scopes feature introduced in 2.1a2, we decided
1391 to make this feature optional, and to wait until Python 2.2 (or at
1392 least 6 months) to make it standard. The option can be enabled on a
1393 per-module basis by adding "from __future__ import nested_scopes" at
1394 the beginning of a module (before any other statements, but after
1395 comments and an optional docstring). See PEP 236 (Back to the
1396 __future__) for a description of the __future__ statement. PEP 227
1397 (Statically Nested Scopes) has been updated to reflect this change,
1398 and to clarify the semantics in a number of endcases.
1399
1400- The nested scopes code, when enabled, has been hardened, and most
1401 bugs and memory leaks in it have been fixed.
1402
1403- Compile-time warnings are now generated for a number of conditions
1404 that will break or change in meaning when nested scopes are enabled:
1405
1406 - Using "from...import *" or "exec" without in-clause in a function
1407 scope that also defines a lambda or nested function with one or
1408 more free (non-local) variables. The presence of the import* or
1409 bare exec makes it impossible for the compiler to determine the
1410 exact set of local variables in the outer scope, which makes it
1411 impossible to determine the bindings for free variables in the
1412 inner scope. To avoid the warning about import *, change it into
1413 an import of explicitly name object, or move the import* statement
1414 to the global scope; to avoid the warning about bare exec, use
1415 exec...in... (a good idea anyway -- there's a possibility that
1416 bare exec will be deprecated in the future).
1417
1418 - Use of a global variable in a nested scope with the same name as a
1419 local variable in a surrounding scope. This will change in
1420 meaning with nested scopes: the name in the inner scope will
1421 reference the variable in the outer scope rather than the global
1422 of the same name. To avoid the warning, either rename the outer
1423 variable, or use a global statement in the inner function.
1424
Neil Schemenauera35c6882001-02-27 04:45:05 +00001425- An optional object allocator has been included. This allocator is
1426 optimized for Python objects and should be faster and use less memory
1427 than the standard system allocator. It is not enabled by default
1428 because of possible thread safety problems. The allocator is only
1429 protected by the Python interpreter lock and it is possible that some
1430 extension modules require a thread safe allocator. The object
1431 allocator can be enabled by providing the "--with-pymalloc" option to
1432 configure.
1433
Tim Petersd66595f2001-02-04 03:09:53 +00001434Standard library
1435
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001436- pyexpat now detects the expat version if expat.h defines it. A
1437 number of additional handlers are provided, which are only available
1438 since expat 1.95. In addition, the methods SetParamEntityParsing and
1439 GetInputContext of Parser objects are available with 1.95.x
1440 only. Parser objects now provide the ordered_attributes and
1441 specified_attributes attributes. A new module expat.model was added,
1442 which offers a number of additional constants if 1.95.x is used.
1443
1444- xml.dom offers the new functions registerDOMImplementation and
1445 getDOMImplementation.
1446
1447- xml.dom.minidom offers a toprettyxml method. A number of DOM
1448 conformance issues have been resolved. In particular, Element now
1449 has an hasAttributes method, and the handling of namespaces was
1450 improved.
1451
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001452- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1453 getting information about live Python code, and pydoc.py, a module
1454 for interactively converting docstrings to HTML or text.
1455 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001456 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001457 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1458 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001459
Tim Peters1eff7962001-03-01 02:31:33 +00001460- New library module difflib.py, primarily packaging the SequenceMatcher
1461 class at the heart of the popular ndiff.py file-comparison tool.
1462
1463- doctest.py (a framework for verifying Python code examples in docstrings)
1464 is now part of the std library.
1465
Tim Petersd66595f2001-02-04 03:09:53 +00001466Windows changes
1467
Guido van Rossume3955a82001-03-02 14:05:59 +00001468- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1469 small GUI that lets you browse the module docstrings using your
1470 default web browser.
1471
Tim Peters1eff7962001-03-01 02:31:33 +00001472- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1473 Platforms) is implemented. See
1474
1475 http://python.sourceforge.net/peps/pep-0235.html
1476
1477 for full details, especially the "Current Lower-Left Semantics" section.
1478 The new Windows import rules are simpler than before:
1479
1480 A. If the PYTHONCASEOK environment variable exists, same as
1481 before: silently accept the first case-insensitive match of any
1482 kind; raise ImportError if none found.
1483
1484 B. Else search sys.path for the first case-sensitive match; raise
1485 ImportError if none found.
1486
1487 The same rules have been implented on other platforms with case-
1488 insensitive but case-preserving filesystems too (including Cygwin, and
1489 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001490
Tim Peters25a9ce32001-02-19 07:06:36 +00001491- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1492 what it's supposed to do (and does do under NT and 2000) via direct
1493 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001494 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001495 all Win9x systems before.
1496
Tim Peters1eff7962001-03-01 02:31:33 +00001497- Build: Subproject _test (effectively) renamed to _testcapi.
1498
Tim Peters2fe289a2001-03-01 22:19:38 +00001499New platforms
1500
1501- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1502 Thanks to Steven Majewski!
1503
1504- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1505 Tishler!
1506
Guido van Rossum9089b272001-03-02 06:49:50 +00001507- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1508 Schwertberger! See RISCOS/README for more information -- it seems
1509 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001510 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001511
Tim Peters25a9ce32001-02-19 07:06:36 +00001512
Tim Petersd7b5e882001-01-25 03:36:26 +00001513What's New in Python 2.1 alpha 2?
1514=================================
Tim Peters40ead762001-01-27 05:35:26 +00001515
Tim Petersd7b5e882001-01-25 03:36:26 +00001516Core language, builtins, and interpreter
1517
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001518- Scopes nest. If a name is used in a function or class, but is not
1519 local, the definition in the nearest enclosing function scope will
1520 be used. One consequence of this change is that lambda statements
1521 could reference variables in the namespaces where the lambda is
1522 defined. In some unusual cases, this change will break code.
1523
1524 In all previous version of Python, names were resolved in exactly
1525 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001526 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001527 function A is defined within a function B, the names bound in B are
1528 not visible in A. The new rules make names bound in B visible in A,
1529 unless A contains a name binding that hides the binding in B.
1530
1531 Section 4.1 of the reference manual describes the new scoping rules
1532 in detail. The test script in Lib/test/test_scope.py demonstrates
1533 some of the effects of the change.
1534
1535 The new rules will cause existing code to break if it defines nested
1536 functions where an outer function has local variables with the same
1537 name as globals or builtins used by the inner function. Example:
1538
1539 def munge(str):
1540 def helper(x):
1541 return str(x)
1542 if type(str) != type(''):
1543 str = helper(str)
1544 return str.strip()
1545
1546 Under the old rules, the name str in helper() is bound to the
1547 builtin function str(). Under the new rules, it will be bound to
1548 the argument named str and an error will occur when helper() is
1549 called.
1550
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001551- The compiler will report a SyntaxError if "from ... import *" occurs
1552 in a function or class scope. The language reference has documented
1553 that this case is illegal, but the compiler never checked for it.
1554 The recent introduction of nested scope makes the meaning of this
1555 form of name binding ambiguous. In a future release, the compiler
1556 may allow this form when there is no possibility of ambiguity.
1557
Tim Peters40ead762001-01-27 05:35:26 +00001558- repr(string) is easier to read, now using hex escapes instead of octal,
1559 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1560
1561 >>> "\texample \r\n" + chr(0) + chr(255)
1562 '\texample \r\n\x00\xff' # in 2.1
1563 '\011example \015\012\000\377' # in 2.0
1564
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001565- Functions are now compared and hashed by identity, not by value, since
1566 the func_code attribute is writable.
1567
Fred Drakefb9d7122001-02-01 20:00:40 +00001568- Weak references (PEP 205) have been added. This involves a few
1569 changes in the core, an extension module (_weakref), and a Python
1570 module (weakref). The weakref module is the public interface. It
1571 includes support for "explicit" weak references, proxy objects, and
1572 mappings with weakly held values.
1573
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001574- A 'continue' statement can now appear in a try block within the body
1575 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001576 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001577
Tim Petersd7b5e882001-01-25 03:36:26 +00001578Standard library
1579
Barry Warsaw30dbd142001-01-31 22:14:01 +00001580- mailbox.py now has a new class, PortableUnixMailbox which is
1581 identical to UnixMailbox but uses a more portable scheme for
1582 determining From_ separators. Also, the constructors for all the
1583 classes in this module have a new optional `factory' argument, which
1584 is a callable used when new message classes must be instantiated by
1585 the next() method.
1586
Tim Petersd7b5e882001-01-25 03:36:26 +00001587- random.py is now self-contained, and offers all the functionality of
1588 the now-deprecated whrandom.py. See the docs for details. random.py
1589 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001590 and restoring the internal state of the generator; and jumpahead(n),
1591 for quickly forcing the internal state to be the same as if n calls to
1592 random() had been made. The latter is particularly useful for multi-
1593 threaded programs, creating one instance of the random.Random() class for
1594 each thread, then using .jumpahead() to force each instance to use a
1595 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001596
Tim Peters0de88fc2001-02-01 04:59:18 +00001597- random.py's seed() function is new. For bit-for-bit compatibility with
1598 prior releases, use the whseed function instead. The new seed function
1599 addresses two problems: (1) The old function couldn't produce more than
1600 about 2**24 distinct internal states; the new one about 2**45 (the best
1601 that can be done in the Wichmann-Hill generator). (2) The old function
1602 sometimes produced identical internal states when passed distinct
1603 integers, and there was no simple way to predict when that would happen;
1604 the new one guarantees to produce distinct internal states for all
1605 arguments in [0, 27814431486576L).
1606
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001607- The socket module now supports raw packets on Linux. The socket
1608 family is AF_PACKET.
1609
Tim Peters9ea17ac2001-02-02 05:57:15 +00001610- test_capi.py is a start at running tests of the Python C API. The tests
1611 are implemented by the new Modules/_testmodule.c.
1612
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001613- A new extension module, _symtable, provides provisional access to the
1614 internal symbol table used by the Python compiler. A higher-level
1615 interface will be added on top of _symtable in a future release.
1616
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001617- Removed the obsolete soundex module.
1618
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001619- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1620 the isSameNode method; NamedNodeMap the get method.
1621
1622- xml.sax.expatreader supports the lexical handler property; it
1623 generates comment, startCDATA, and endCDATA events.
1624
Tim Petersee826f82001-01-31 19:39:44 +00001625Windows changes
1626
1627- Build procedure: the zlib project is built in a different way that
1628 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001629 the zlib binary used. See PCbuild\readme.txt for details. Your old
1630 zlib-related directories can be deleted; you'll need to download fresh
1631 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001632
Tim Peters9ea17ac2001-02-02 05:57:15 +00001633- Build: New subproject _test for the benefit of test_capi.py (see above).
1634
Tim Petersb16c56f2001-02-02 21:24:51 +00001635- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1636 interface to some Python compiler internals).
1637
1638- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001639 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001640
Tim Petersa3a3a032000-11-30 05:22:44 +00001641What's New in Python 2.1 alpha 1?
1642=================================
1643
1644Core language, builtins, and interpreter
1645
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001646- There is a new Unicode companion to the PyObject_Str() API
1647 called PyObject_Unicode(). It behaves in the same way as the
1648 former, but assures that the returned value is an Unicode object
1649 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001650
Guido van Rossumf98eda02001-01-17 15:54:45 +00001651- The comparison operators support "rich comparison overloading" (PEP
1652 207). C extension types can provide a rich comparison function in
1653 the new tp_richcompare slot in the type object. The cmp() function
1654 and the C function PyObject_Compare() first try the new rich
1655 comparison operators before trying the old 3-way comparison. There
1656 is also a new C API PyObject_RichCompare() (which also falls back on
1657 the old 3-way comparison, but does not constrain the outcome of the
1658 rich comparison to a Boolean result).
1659
1660 The rich comparison function takes two objects (at least one of
1661 which is guaranteed to have the type that provided the function) and
1662 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1663 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1664 object, which may be NotImplemented (in which case the tp_compare
1665 slot function is used as a fallback, if defined).
1666
1667 Classes can overload individual comparison operators by defining one
1668 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001669 __ge__. There are no explicit "reflected argument" versions of
1670 these; instead, __lt__ and __gt__ are each other's reflection,
1671 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1672 reflection (similar at the C level). No other implications are
1673 made; in particular, Python does not assume that == is the Boolean
1674 inverse of !=, or that < is the Boolean inverse of >=. This makes
1675 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001676
1677 Classes or types that want to implement (in)equality tests but not
1678 the ordering operators (i.e. unordered types) should implement ==
1679 and !=, and raise an error for the ordering operators.
1680
Guido van Rossuma88479f2001-01-18 14:28:08 +00001681 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001682 Boolean; e.g. a matrix type might want to return a matrix of bits
1683 for A < B, giving elementwise comparisons. Such types should ensure
1684 that any interpretation of their value in a Boolean context raises
1685 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1686 at the C level) to always raise an exception.
1687
Guido van Rossuma88479f2001-01-18 14:28:08 +00001688- Complex numbers use rich comparisons to define == and != but raise
1689 an exception for <, <=, > and >=. Unfortunately, this also means
1690 that cmp() of two complex numbers raises an exception when the two
1691 numbers differ. Since it is not mathematically meaningful to compare
1692 complex numbers except for equality, I hope that this doesn't break
1693 too much code.
1694
Tim Peters3389f192001-02-18 08:48:49 +00001695- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001696 not defined by the language, other than that it's arbitrary but
1697 consistent (see the Reference Manual). An implementation detail changed
1698 in 2.1a1 such that None now compares less than any other object. Code
1699 relying on this new behavior (like code that relied on the previous
1700 behavior) does so at its own risk.
1701
Barry Warsaw573b5412001-01-15 20:43:18 +00001702- Functions and methods now support getting and setting arbitrarily
1703 named attributes (PEP 232). Functions have a new __dict__
1704 (a.k.a. func_dict) which hold the function attributes. Methods get
1705 and set attributes on their underlying im_func. It is a TypeError
1706 to set an attribute on a bound method.
1707
Guido van Rossum051e3352001-01-15 19:11:10 +00001708- The xrange() object implementation has been improved so that
1709 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1710 limitation that in this case len(xrange(sys.maxint)) can't be
1711 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1712 work fine as long as the index i doesn't actually reach 2**31.
1713 (Python uses regular ints for sequence and string indices; fixing
1714 that is much more work.)
1715
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001716- Two changes to from...import:
1717
Guido van Rossumba381232001-02-03 15:06:40 +00001718 1) "from M import X" now works even if (after loading module M)
1719 sys.modules['M'] is not a real module; it's basically a getattr()
1720 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001721
1722 2) "from M import *" now looks for M.__all__ to decide which names to
1723 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1724 filters out names starting with '_' as before. Whether or not
1725 __all__ exists, there's no restriction on the type of M.
1726
Guido van Rossumf61f1662001-01-10 20:13:55 +00001727- File objects have a new method, xreadlines(). This is the fastest
1728 way to iterate over all lines in a file:
1729
1730 for line in file.xreadlines():
1731 ...do something to line...
1732
1733 See the xreadlines module (mentioned below) for how to do this for
1734 other file-like objects.
1735
1736- Even if you don't use file.xreadlines(), you may expect a speedup on
1737 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001738 quite a bit in platform-specific ways: on systems (like Linux) that
1739 support flockfile(), getc_unlocked(), and funlockfile(), those are
1740 used by default. On systems (like Windows) without getc_unlocked(),
1741 a complicated (but still thread-safe) method using fgets() is used by
1742 default.
1743
Tim Petersd52269b2001-01-25 06:23:18 +00001744 You can force use of the fgets() method by #define'ing
1745 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001746 getc_unlocked()).
1747
Tim Petersd52269b2001-01-25 06:23:18 +00001748 You can force fgets() not to be used by #define'ing
1749 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001750 test_bufio.py fails -- and let us know if it does!).
1751
1752- In addition, the fileinput module, while still slower than the other
1753 methods on most platforms, has been sped up too, by using
1754 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001755
1756- Support for run-time warnings has been added, including a new
1757 command line option (-W) to specify the disposition of warnings.
1758 See the description of the warnings module below.
1759
1760- Extensive changes have been made to the coercion code. This mostly
1761 affects extension modules (which can now implement mixed-type
1762 numerical operators without having to use coercion), but
1763 occasionally, in boundary cases the coercion semantics have changed
1764 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001765 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001766 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001767 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001768
Guido van Rossumf98eda02001-01-17 15:54:45 +00001769- In connection with the coercion changes, a new built-in singleton
1770 object, NotImplemented is defined. This can be returned for
1771 operations that wish to indicate they are not implemented for a
1772 particular combination of arguments. From C, this is
1773 Py_NotImplemented.
1774
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001775- The interpreter accepts now bytecode files on the command line even
1776 if they do not have a .pyc or .pyo extension. On Linux, after executing
1777
Martin v. Löwise214baa2001-02-04 22:37:56 +00001778import imp,sys,string
1779magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1780reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1781open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001782
1783 any byte code file can be used as an executable (i.e. as an argument
1784 to execve(2)).
1785
Tim Peters9940b802000-12-01 07:59:35 +00001786- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001787 character. In 1.6 and earlier, they never produced a sign,
1788 and raised an error if the value of the long was too large
1789 to fit in a Python int. In 2.0, they produced a sign if and
1790 only if too large to fit in an int. This was inconsistent
1791 across platforms (because the size of an int varies across
1792 platforms), and inconsistent with hex() and oct(). Example:
1793
1794 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001795 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001796 'ffffffbe' # in 2.0 and before, on 32-bit machines
1797 >>> hex(-0x42L)
1798 '-0x42L' # in all versions of Python
1799
Tim Peters9940b802000-12-01 07:59:35 +00001800 The behavior of %d formats for negative Python longs remains
1801 the same as in 2.0 (although in 1.6 and before, they raised
1802 an error if the long didn't fit in a Python int).
1803
1804 %u formats don't make sense for Python longs, but are allowed
1805 and treated the same as %d in 2.1. In 2.0, a negative long
1806 formatted via %u produced a sign if and only if too large to
1807 fit in an int. In 1.6 and earlier, a negative long formatted
1808 via %u raised an error if it was too big to fit in an int.
1809
Guido van Rossum3661d392000-12-12 22:10:31 +00001810- Dictionary objects have an odd new method, popitem(). This removes
1811 an arbitrary item from the dictionary and returns it (in the form of
1812 a (key, value) pair). This can be useful for algorithms that use a
1813 dictionary as a bag of "to do" items and repeatedly need to pick one
1814 item. Such algorithms normally end up running in quadratic time;
1815 using popitem() they can usually be made to run in linear time.
1816
Tim Peters36cdad12000-12-29 02:06:45 +00001817Standard library
1818
Thomas Woutersfe385252001-01-19 23:16:56 +00001819- In the time module, the time argument to the functions strftime,
1820 localtime, gmtime, asctime and ctime is now optional, defaulting to
1821 the current time (in the local timezone).
1822
Guido van Rossumda91f222001-01-15 16:36:08 +00001823- The ftplib module now defaults to passive mode, which is deemed a
1824 more useful default given that clients are often inside firewalls
1825 these days. Note that this could break if ftplib is used to connect
1826 to a *server* that is inside a firewall, from outside; this is
1827 expected to be a very rare situation. To fix that, you can call
1828 ftp.set_pasv(0).
1829
Martin v. Löwis10a27872001-01-13 09:54:41 +00001830- The module site now treats .pth files not only for path configuration,
1831 but also supports extensions to the initialization code: Lines starting
1832 with import are executed.
1833
Guido van Rossumf61f1662001-01-10 20:13:55 +00001834- There's a new module, warnings, which implements a mechanism for
1835 issuing and filtering warnings. There are some new built-in
1836 exceptions that serve as warning categories, and a new command line
1837 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1838 turns warnings into errors). warnings.warn(message[, category])
1839 issues a warning message; this can also be called from C as
1840 PyErr_Warn(category, message).
1841
1842- A new module xreadlines was added. This exports a single factory
1843 function, xreadlines(). The intention is that this code is the
1844 absolutely fastest way to iterate over all lines in an open
1845 file(-like) object:
1846
1847 import xreadlines
1848 for line in xreadlines.xreadlines(file):
1849 ...do something to line...
1850
1851 This is equivalent to the previous the speed record holder using
1852 file.readlines(sizehint). Note that if file is a real file object
1853 (as opposed to a file-like object), this is equivalent:
1854
1855 for line in file.xreadlines():
1856 ...do something to line...
1857
Tim Peters36cdad12000-12-29 02:06:45 +00001858- The bisect module has new functions bisect_left, insort_left,
1859 bisect_right and insort_right. The old names bisect and insort
1860 are now aliases for bisect_right and insort_right. XXX_right
1861 and XXX_left methods differ in what happens when the new element
1862 compares equal to one or more elements already in the list: the
1863 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001864 right. Code that doesn't care where equal elements end up should
1865 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001866
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001867- The new curses.panel module wraps the panel library that forms part
1868 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1869
Guido van Rossumf61f1662001-01-10 20:13:55 +00001870- The SocketServer module now sets the allow_reuse_address flag by
1871 default in the TCPServer class.
1872
1873- A new function, sys._getframe(), returns the stack frame pointer of
1874 the caller. This is intended only as a building block for
1875 higher-level mechanisms such as string interpolation.
1876
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001877- The pyexpat module supports a number of new handlers, which are
1878 available only in expat 1.2. If invocation of a callback fails, it
1879 will report an additional frame in the traceback. Parser objects
1880 participate now in garbage collection. If expat reports an unknown
1881 encoding, pyexpat will try to use a Python codec; that works only
1882 for single-byte charsets. The parser type objects is exposed as
1883 XMLParserObject.
1884
1885- xml.dom now offers standard definitions for symbolic node type and
1886 exception code constants, and a hierarchy of DOM exceptions. minidom
1887 was adjusted to use them.
1888
1889- The conformance of xml.dom.minidom to the DOM specification was
1890 improved. It detects a number of additional error cases; the
1891 previous/next relationship works even when the tree is modified;
1892 Node supports the normalize() method; NamedNodeMap, DocumentType and
1893 DOMImplementation classes were added; Element supports the
1894 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1895 method.
1896
Guido van Rossumf61f1662001-01-10 20:13:55 +00001897Build issues
1898
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001899- For Unix (and Unix-compatible) builds, configuration and building of
1900 extension modules is now greatly automated. Rather than having to
1901 edit the Modules/Setup file to indicate which modules should be
1902 built and where their include files and libraries are, a
1903 distutils-based setup.py script now takes care of building most
1904 extension modules. All extension modules built this way are built
1905 as shared libraries. Only a few modules that must be linked
1906 statically are still listed in the Setup file; you won't need to
1907 edit their configuration.
1908
1909- Python should now build out of the box on Cygwin. If it doesn't,
1910 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001911
1912- Python now always uses its own (renamed) implementation of getopt()
1913 -- there's too much variation among C library getopt()
1914 implementations.
1915
1916- C++ compilers are better supported; the CXX macro is always set to a
1917 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001918
Tim Petersd92dfe02000-12-12 01:18:41 +00001919Windows changes
1920
1921- select module: By default under Windows, a select() call
1922 can specify no more than 64 sockets. Python now boosts
1923 this Microsoft default to 512. If you need even more than
1924 that, see the MS docs (you'll need to #define FD_SETSIZE
1925 and recompile Python from source).
1926
Guido van Rossumf61f1662001-01-10 20:13:55 +00001927- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1928 subdirectory is no more!
1929
Tim Petersa3a3a032000-11-30 05:22:44 +00001930
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001931What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001932=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001933
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001934Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001935changes are in the file HISTORY. If you are making the jump directly
1936from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1937HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001938
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001939Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1940the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1941http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001942
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001943--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001944
1945======================================================================
1946
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001947What's new in 2.0 (since release candidate 1)?
1948==============================================
1949
1950Standard library
1951
1952- The copy_reg module was modified to clarify its intended use: to
1953 register pickle support for extension types, not for classes.
1954 pickle() will raise a TypeError if it is passed a class.
1955
1956- Fixed a bug in gettext's "normalize and expand" code that prevented
1957 it from finding an existing .mo file.
1958
1959- Restored support for HTTP/0.9 servers in httplib.
1960
Tim Peters989b7b92000-10-16 20:24:53 +00001961- The math module was changed to stop raising OverflowError in case of
1962 underflow, and return 0 instead in underflow cases. Whether Python
1963 used to raise OverflowError in case of underflow was platform-
1964 dependent (it did when the platform math library set errno to ERANGE
1965 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001966
1967- Fixed a bug in StringIO that occurred when the file position was not
1968 at the end of the file and write() was called with enough data to
1969 extend past the end of the file.
1970
1971- Fixed a bug that caused Tkinter error messages to get lost on
1972 Windows. The bug was fixed by replacing direct use of
1973 interp->result with Tcl_GetStringResult(interp).
1974
1975- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1976 redirect response.
1977
1978- Several changes were made to distutils: Some debugging code was
1979 removed from util. Fixed the installer used when an external zip
1980 program (like WinZip) is not found; the source code for this
1981 installer is in Misc/distutils. check_lib() was modified to behave
1982 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1983 test for whether installed modules are on sys.path was changed to
1984 use both normcase() and normpath().
1985
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001986- Several minor bugs were fixed in the xml package (the minidom,
1987 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001988
1989- The regression test driver (regrtest.py) behavior when invoked with
1990 -l changed: It now reports a count of objects that are recognized as
1991 garbage but not freed by the garbage collector.
1992
Tim Peters989b7b92000-10-16 20:24:53 +00001993- The regression test for the math module was changed to test
1994 exceptional behavior when the test is run in verbose mode. Python
1995 cannot yet guarantee consistent exception behavior across platforms,
1996 so the exception part of test_math is run only in verbose mode, and
1997 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001998
1999Internals
2000
2001- PyOS_CheckStack() has been disabled on Win64, where it caused
2002 test_sre to fail.
2003
2004Build issues
2005
2006- Changed compiler flags, so that gcc is always invoked with -Wall and
2007 -Wstrict-prototypes. Users compiling Python with GCC should see
2008 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002009 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002010 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002011
Tim Petersa3a3a032000-11-30 05:22:44 +00002012- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002013
2014Tools and other miscellany
2015
2016- The compiler in Tools/compiler was updated to support the new
2017 language features introduced in 2.0: extended print statement, list
2018 comprehensions, and augmented assignments. The new compiler should
2019 also be backwards compatible with Python 1.5.2; the compiler will
2020 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002021 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002022
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002023What's new in 2.0 release candidate 1 (since beta 2)?
2024=====================================================
2025
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002026What is release candidate 1?
2027
2028We believe that release candidate 1 will fix all known bugs that we
2029intend to fix for the 2.0 final release. This release should be a bit
2030more stable than the previous betas. We would like to see even more
2031widespread testing before the final release, so we are producing this
2032release candidate. The final release will be exactly the same unless
2033any show-stopping (or brown bag) bugs are found by testers of the
2034release candidate.
2035
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002036All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002037to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002038
2039Core language, builtins, and interpreter
2040
2041- A bug that caused crashes when __coerce__ was used with augmented
2042 assignment, e.g. +=, was fixed.
2043
2044- Raise ZeroDivisionError when raising zero to a negative number,
2045 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2046 power operator and the result of math.pow(0.0, -2.0) will vary by
2047 platform. On Linux, it raises a ValueError.
2048
2049- A bug in Unicode string interpolation was fixed that occasionally
2050 caused errors with formats including "%%". For example, the
2051 following expression "%% %s" % u"abc" no longer raises a TypeError.
2052
2053- Compilation of deeply nested expressions raises MemoryError instead
2054 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2055
2056- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2057 rendering them useless. They are now written in binary mode again.
2058
2059Standard library
2060
2061- Keyword arguments are now accepted for most pattern and match object
2062 methods in SRE, the standard regular expression engine.
2063
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002064- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002065 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002066
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002067- Several bugs in the Unicode handling and error handling in _tkinter
2068 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002069
2070- Fix memory management errors in Merge() and Tkapp_Call() routines.
2071
2072- Several changes were made to cStringIO to make it compatible with
2073 the file-like object interface and with StringIO. If operations are
2074 performed on a closed object, an exception is raised. The truncate
2075 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002076 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002077
2078- There were many changes made to the linuxaudiodev module and its
2079 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002080 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002081
2082 Note that this module is named poorly, because it should work
2083 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002084 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002085
2086 The module now raises exceptions when errors occur instead of
2087 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2088 audio) and defines a getptr() method that calls the
2089 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2090
2091- The library_version attribute, introduced in an earlier beta, was
2092 removed because it can not be supported with early versions of the C
2093 readline library, which provides no way to determine the version at
2094 compile-time.
2095
2096- The binascii module is now enabled on Win64.
2097
Tim Peters46446d62000-10-09 21:19:31 +00002098- tokenize.py no longer suffers "recursion depth" errors when parsing
2099 programs with very long string literals.
2100
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002101Internals
2102
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002103- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002104 which is called when the interpreter starts up to determine where
2105 the standard library is installed. These vulnerabilities affect all
2106 previous versions of Python and can be exploited by setting very
2107 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2108 setuid Python script, although use of the wrapper in
2109 Misc/setuid-prog.c will eliminate the vulnerability.
2110
2111- Fixed garbage collection bugs in instance creation that were
2112 triggered when errors occurred during initialization. The solution,
2113 applied in cPickle and in PyInstance_New(), is to call
2114 PyObject_GC_Init() after the initialization of the object's
2115 container attributes is complete.
2116
2117- pyexpat adds definitions of PyModule_AddStringConstant and
2118 PyModule_AddObject if the Python version is less than 2.0, which
2119 provides compatibility with PyXML on Python 1.5.2.
2120
2121- If the platform has a bogus definition for LONG_BIT (the number of
2122 bits in a long), an error will be reported at compile time.
2123
2124- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2125 collection crashes and possibly other, unreported crashes.
2126
2127- Fixed a memory leak in _PyUnicode_Fini().
2128
2129Build issues
2130
2131- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002132 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002133 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002134
2135- The mmap.PAGESIZE constant is now initialized using sysconf when
2136 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2137
2138- The md5 file should now compile on all platforms.
2139
2140- The select module now compiles on platforms that do not define
2141 POLLRDNORM and related constants.
2142
2143- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002144 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002145
Jeremy Hylton10921202000-10-09 18:34:12 +00002146- BeOS: A number of changes were made to the build and installation
2147 process. ar-fake now operates on a directory of object files.
2148 dl_export.h is gone, and its macros now appear on the mwcc command
2149 line during build on PPC BeOS.
2150
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002151- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002152 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002153
2154- Cygwin: Support for shared libraries, Tkinter, and sockets.
2155
2156- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2157
2158Tools and other miscellany
2159
2160- Removed debugging prints from main used with freeze.
2161
Tim Peters46446d62000-10-09 21:19:31 +00002162- IDLE auto-indent no longer crashes when it encounters Unicode
2163 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002164
2165What's new in 2.0 beta 2 (since beta 1)?
2166========================================
2167
2168Core language, builtins, and interpreter
2169
Tim Peters482c0212000-09-26 06:33:09 +00002170- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002171 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002172
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002173- Add -h and -V command line options to print the usage message and
2174 Python version number and exit immediately.
2175
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002176- eval() and exec accept Unicode objects as code parameters.
2177
2178- getattr() and setattr() now also accept Unicode objects for the
2179 attribute name, which are converted to strings using the default
2180 encoding before lookup.
2181
2182- Multiplication on string and Unicode now does proper bounds
2183 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2184 string is too long."
2185
2186- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002187 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002188
Jeremy Hylton1b618592000-09-26 05:32:36 +00002189
2190Standard library and extensions
2191
Guido van Rossum5b08f132001-04-16 02:05:23 +00002192- socket module: the OpenSSL code now adds support for RAND_status()
2193 and EGD (Entropy Gathering Device).
2194
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002195- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002196 argument checking; it still takes no arguments.
2197
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002198- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002199
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002200- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002201
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002202- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002203
2204- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002205 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002206
2207- copy: Copy Unicode objects atomically.
2208
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002209- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002210
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002211- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002212
Fred Drake67233bc2000-09-26 16:40:27 +00002213- dbm: Add get() and setdefault() methods to dbm object. Add constant
2214 `library' to module that names the library used. Added doc strings
2215 and method names to error messages. Uses configure to determine
2216 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2217 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002218
2219- distutils: Update to version 0.9.3.
2220
2221- dl: Add several dl.RTLD_ constants.
2222
2223- fpectl: Now supported on FreeBSD.
2224
2225- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2226 found by the collector will be saved in gc.garbage. This is useful
2227 for debugging a program that creates reference cycles.
2228
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002229- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002230 of HTTP class. Do not close socket on zero-length response. Do not
2231 crash when server sends invalid content-length header.
2232
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002233- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002234
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002235- marshal: When reading a short, sign-extend on platforms where shorts
2236 are bigger than 16 bits. When reading a long, repair the unportable
2237 sign extension that was being done for 64-bit machines. (It assumed
2238 that signed right shift sign-extends.)
2239
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002240- operator: Add contains(), invert(), __invert__() as aliases for
2241 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002242
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002243- os: Add support for popen2() and popen3() on all platforms where
2244 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002245
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002246- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002247 clicking on a file in Explorer (or passing the file name to the
2248 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002249
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002250- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002251 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002252
2253- pickle: Now raises ValueError when an invalid pickle that contains
2254 a non-string repr where a string repr was expected. This behavior
2255 matches cPickle.
2256
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002257- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002258
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002259- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002260
2261- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002262 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002263 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002264
2265- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002266 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002267
2268- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002269 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002270 few cycles during startup since the first call to
2271 setdefaultencoding() will initialize the codec registry and the
2272 encodings package.
2273
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002274- socket: Support for size hint in readlines() method of object returned
2275 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002276
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002277- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002278 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002279 is followed by whitespace.
2280
Tim Petersa3a3a032000-11-30 05:22:44 +00002281- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002282
2283- struct: Check ranges for bytes and shorts.
2284
2285- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002286 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002287
2288- Tkinter: Image objects are now guaranteed to have unique ids. Set
2289 event.delta to zero if Tk version doesn't support mousewheel.
2290 Removed some debugging prints.
2291
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002292- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002293
Fred Drake67233bc2000-09-26 16:40:27 +00002294- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002295 which works around a bug in Norton AntiVirus 2000 that leads directly
2296 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002297
2298- xml: New version detection code allows PyXML to override standard
2299 XML package if PyXML version is greater than 0.6.1.
2300
Fred Drake64bb3802000-09-26 16:21:35 +00002301- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2302 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2303 tree only for nodes which are sufficiently interesting to a specific
2304 application. Does not provide the HTML-specific extensions. Still
2305 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002306
Fred Drake64bb3802000-09-26 16:21:35 +00002307- xml.sax: SAX 2 support for Python, including all the handler
2308 interfaces needed to process XML 1.0 compliant XML. Some
2309 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002310
Fred Drake64bb3802000-09-26 16:21:35 +00002311- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2312 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002313
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002314
Jeremy Hylton1b618592000-09-26 05:32:36 +00002315C API
2316
2317- Add three new convenience functions for module initialization --
2318 PyModule_AddObject(), PyModule_AddIntConstant(), and
2319 PyModule_AddStringConstant().
2320
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002321- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002322 removed and add #error to Python.h if NULL isn't defined after
2323 #include of stdio.h.
2324
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002325- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002326 backwards compatibility (at the source level) with old extensions.
2327
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002328- A wrapper API was added for signal() and sigaction(). Instead of
2329 either function, always use PyOS_getsig() to get a signal handler
2330 and PyOS_setsig() to set one. A new convenience typedef
2331 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002332
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002333- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002334 internal data buffer and size of a string object -- or the default
2335 encoded version of a Unicode object.
2336
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002337- PyString_Size() and PyString_AsString() accept Unicode objects.
2338
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002339- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002340 exists). INT_MAX and LONG_MAX will always be defined, even if
2341 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002342
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002343- PyFloat_FromString takes a second argument, pend, that was
2344 effectively useless. It is now officially useless but preserved for
2345 backwards compatibility. If the pend argument is not NULL, *pend is
2346 set to NULL.
2347
2348- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2349 for the attribute name. See note on getattr() above.
2350
2351- A few bug fixes to argument processing for Unicode.
2352 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2353 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2354 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002355 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002356
2357- Py_BuildValue accepts B format (for bgen-generated code).
2358
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002359
Jeremy Hylton1b618592000-09-26 05:32:36 +00002360Internals
2361
2362- On Unix, fix code for finding Python installation directory so that
2363 it works when argv[0] is a relative path.
2364
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002365- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002366 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002367 rather than by generating a copy of the object.
2368
Tim Peters482c0212000-09-26 06:33:09 +00002369- Several of the internal Unicode tables are much smaller now, and
2370 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002371
Jeremy Hylton97693b02000-09-26 17:42:51 +00002372- In the garbage collector: Fixed bug in collection of tuples. Fixed
2373 bug that caused some instances to be removed from the container set
2374 while they were still live. Fixed parsing in gc.set_debug() for
2375 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002376
2377- Fixed refcount problem in instance deallocation that only occurred
2378 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2379
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002380- On Windows, getpythonregpath is now protected against null data in
2381 registry key.
2382
2383- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002384 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002385
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002386
Jeremy Hylton1b618592000-09-26 05:32:36 +00002387Build and platform-specific issues
2388
2389- Better support of GNU Pth via --with-pth configure option.
2390
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002391- Python/C API now properly exposed to dynamically-loaded extension
2392 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002393
2394- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2395 Don't define MS_SYNC to be zero when it is undefined. Added missing
2396 prototypes in posixmodule.c.
2397
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002398- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002399 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002400
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002401- Fix largefile support on older NetBSD systems and OpenBSD by adding
2402 define for TELL64.
2403
2404
2405Tools and other miscellany
2406
2407- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2408
2409- freeze: The modulefinder now works with 2.0 opcodes.
2410
Tim Petersa3a3a032000-11-30 05:22:44 +00002411- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002412 Move hackery of sys.argv until after the Tk instance has been
2413 created, which allows the application-specific Tkinter
2414 initialization to be executed if present; also pass an explicit
2415 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002416
Jeremy Hylton1b618592000-09-26 05:32:36 +00002417
2418What's new in 2.0 beta 1?
2419=========================
2420
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002421Source Incompatibilities
2422------------------------
2423
2424None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2425such as single-argument append(), connect() and bind(), and changes to
2426str(long) and repr(float).
2427
2428
2429Binary Incompatibilities
2430------------------------
2431
2432- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2433with Python 2.0; these extensions will have to be rebuilt for Python
24342.0.
2435
2436- On Windows, attempting to import a third party extension built for
2437Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2438can do about this. Check your PYTHONPATH environment variable!
2439
2440- Python bytecode files (*.pyc and *.pyo) are not compatible between
2441releases.
2442
2443
2444Overview of Changes Since 1.6
2445-----------------------------
2446
2447There are many new modules (including brand new XML support through
2448the xml package, and i18n support through the gettext module); a list
2449of all new modules is included below. Lots of bugs have been fixed.
2450
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002451The process for making major new changes to the language has changed
2452since Python 1.6. Enhancements must now be documented by a Python
2453Enhancement Proposal (PEP) before they can be accepted.
2454
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002455There are several important syntax enhancements, described in more
2456detail below:
2457
2458 - Augmented assignment, e.g. x += 1
2459
2460 - List comprehensions, e.g. [x**2 for x in range(10)]
2461
2462 - Extended import statement, e.g. import Module as Name
2463
2464 - Extended print statement, e.g. print >> file, "Hello"
2465
2466Other important changes:
2467
2468 - Optional collection of cyclical garbage
2469
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002470Python Enhancement Proposal (PEP)
2471---------------------------------
2472
2473PEP stands for Python Enhancement Proposal. A PEP is a design
2474document providing information to the Python community, or describing
2475a new feature for Python. The PEP should provide a concise technical
2476specification of the feature and a rationale for the feature.
2477
2478We intend PEPs to be the primary mechanisms for proposing new
2479features, for collecting community input on an issue, and for
2480documenting the design decisions that have gone into Python. The PEP
2481author is responsible for building consensus within the community and
2482documenting dissenting opinions.
2483
2484The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002485
2486Augmented Assignment
2487--------------------
2488
2489This must have been the most-requested feature of the past years!
2490Eleven new assignment operators were added:
2491
Guido van Rossume905e952000-09-05 12:42:46 +00002492 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002493
2494For example,
2495
2496 A += B
2497
2498is similar to
2499
2500 A = A + B
2501
2502except that A is evaluated only once (relevant when A is something
2503like dict[index].attr).
2504
2505However, if A is a mutable object, A may be modified in place. Thus,
2506if A is a number or a string, A += B has the same effect as A = A+B
2507(except A is only evaluated once); but if a is a list, A += B has the
2508same effect as A.extend(B)!
2509
2510Classes and built-in object types can override the new operators in
2511order to implement the in-place behavior; the not-in-place behavior is
2512used automatically as a fallback when an object doesn't implement the
2513in-place behavior. For classes, the method name is derived from the
2514method name for the corresponding not-in-place operator by inserting
2515an 'i' in front of the name, e.g. __iadd__ implements in-place
2516__add__.
2517
2518Augmented assignment was implemented by Thomas Wouters.
2519
2520
2521List Comprehensions
2522-------------------
2523
2524This is a flexible new notation for lists whose elements are computed
2525from another list (or lists). The simplest form is:
2526
2527 [<expression> for <variable> in <sequence>]
2528
Guido van Rossum56db0952000-09-06 23:34:25 +00002529For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002530This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002531
2532You can also add a condition:
2533
2534 [<expression> for <variable> in <sequence> if <condition>]
2535
2536For example, [w for w in words if w == w.lower()] would yield the list
2537of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002538than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002539
2540You can also have nested for loops and more than one 'if' clause. For
2541example, here's a function that flattens a sequence of sequences::
2542
2543 def flatten(seq):
2544 return [x for subseq in seq for x in subseq]
2545
2546 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2547
2548This prints
2549
2550 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2551
2552List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002553Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002554
2555
2556Extended Import Statement
2557-------------------------
2558
2559Many people have asked for a way to import a module under a different
2560name. This can be accomplished like this:
2561
2562 import foo
2563 bar = foo
2564 del foo
2565
2566but this common idiom gets old quickly. A simple extension of the
2567import statement now allows this to be written as follows:
2568
2569 import foo as bar
2570
2571There's also a variant for 'from ... import':
2572
2573 from foo import bar as spam
2574
2575This also works with packages; e.g. you can write this:
2576
2577 import test.regrtest as regrtest
2578
2579Note that 'as' is not a new keyword -- it is recognized only in this
2580context (this is only possible because the syntax for the import
2581statement doesn't involve expressions).
2582
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002583Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002584
2585
2586Extended Print Statement
2587------------------------
2588
2589Easily the most controversial new feature, this extension to the print
2590statement adds an option to make the output go to a different file
2591than the default sys.stdout.
2592
2593For example, to write an error message to sys.stderr, you can now
2594write:
2595
2596 print >> sys.stderr, "Error: bad dog!"
2597
2598As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002599evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002600
2601 print >> None, "Hello world"
2602
2603is equivalent to
2604
2605 print "Hello world"
2606
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002607Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002608
2609
2610Optional Collection of Cyclical Garbage
2611---------------------------------------
2612
2613Python is now equipped with a garbage collector that can hunt down
2614cyclical references between Python objects. It's no replacement for
2615reference counting; in fact, it depends on the reference counts being
2616correct, and decides that a set of objects belong to a cycle if all
2617their reference counts can be accounted for from their references to
2618each other. This devious scheme was first proposed by Eric Tiedemann,
2619and brought to implementation by Neil Schemenauer.
2620
2621There's a module "gc" that lets you control some parameters of the
2622garbage collection. There's also an option to the configure script
2623that lets you enable or disable the garbage collection. In 2.0b1,
2624it's on by default, so that we (hopefully) can collect decent user
2625experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002626performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002627off by default in the final 2.0 release.
2628
2629
2630Smaller Changes
2631---------------
2632
2633A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2634map(None, seq1, seq2, ...) when the sequences have the same length;
2635i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2636the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002637zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002638
2639sys.version_info is a tuple (major, minor, micro, level, serial).
2640
2641Dictionaries have an odd new method, setdefault(key, default).
2642dict.setdefault(key, default) returns dict[key] if it exists; if not,
2643it sets dict[key] to default and returns that value. Thus:
2644
2645 dict.setdefault(key, []).append(item)
2646
2647does the same work as this common idiom:
2648
2649 if not dict.has_key(key):
2650 dict[key] = []
2651 dict[key].append(item)
2652
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002653There are two new variants of SyntaxError that are raised for
2654indentation-related errors: IndentationError and TabError.
2655
2656Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2657escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002658
2659The limits on the size of expressions and file in Python source code
2660have been raised from 2**16 to 2**32. Previous versions of Python
2661were limited because the maximum argument size the Python VM accepted
2662was 2**16. This limited the size of object constructor expressions,
2663e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2664limit was raised thanks to a patch by Charles Waldman that effectively
2665fixes the problem. It is now much more likely that you will be
2666limited by available memory than by an arbitrary limit in Python.
2667
2668The interpreter's maximum recursion depth can be modified by Python
2669programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2670limit is the maximum number of recursive calls that can be made by
2671Python code. The limit exists to prevent infinite recursion from
2672overflowing the C stack and causing a core dump. The default value is
26731000. The maximum safe value for a particular platform can be found
2674by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002675
2676New Modules and Packages
2677------------------------
2678
2679atexit - for registering functions to be called when Python exits.
2680
2681imputil - Greg Stein's alternative API for writing custom import
2682hooks.
2683
2684pyexpat - an interface to the Expat XML parser, contributed by Paul
2685Prescod.
2686
2687xml - a new package with XML support code organized (so far) in three
2688subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2689would fill a volume. There's a special feature whereby a
2690user-installed package named _xmlplus overrides the standard
2691xmlpackage; this is intended to give the XML SIG a hook to distribute
2692backwards-compatible updates to the standard xml package.
2693
2694webbrowser - a platform-independent API to launch a web browser.
2695
2696
Guido van Rossume905e952000-09-05 12:42:46 +00002697Changed Modules
2698---------------
2699
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002700array -- new methods for array objects: count, extend, index, pop, and
2701remove
2702
2703binascii -- new functions b2a_hex and a2b_hex that convert between
2704binary data and its hex representation
2705
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002706calendar -- Many new functions that support features including control
2707over which day of the week is the first day, returning strings instead
2708of printing them. Also new symbolic constants for days of week,
2709e.g. MONDAY, ..., SUNDAY.
2710
2711cgi -- FieldStorage objects have a getvalue method that works like a
2712dictionary's get method and returns the value attribute of the object.
2713
2714ConfigParser -- The parser object has new methods has_option,
2715remove_section, remove_option, set, and write. They allow the module
2716to be used for writing config files as well as reading them.
2717
2718ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002719optionally support the RFC 959 REST command.
2720
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002721gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002722
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002723httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2724the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002725
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002726locale -- implement getdefaultlocale for Win32 and Macintosh
2727
2728marshal -- no longer dumps core when marshaling deeply nested or
2729recursive data structures
2730
2731os -- new functions isatty, seteuid, setegid, setreuid, setregid
2732
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002733os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2734support under Unix.
2735
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002736os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002737
2738os.path -- fix semantics of os.path.commonprefix
2739
2740smtplib -- support for sending very long messages
2741
2742socket -- new function getfqdn()
2743
2744readline -- new functions to read, write and truncate history files.
2745The readline section of the library reference manual contains an
2746example.
2747
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002748select -- add interface to poll system call
2749
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002750shutil -- new copyfileobj function
2751
2752SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2753HTTP server.
2754
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002755Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002756
2757urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002758e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002759
2760whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002761
2762
2763Obsolete Modules
2764----------------
2765
2766None. However note that 1.6 made a whole slew of modules obsolete:
2767stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2768poly, zmod, strop, util, whatsound.
2769
2770
2771Changed, New, Obsolete Tools
2772----------------------------
2773
Tim Peters8b092332000-09-05 20:15:25 +00002774None.
Guido van Rossume905e952000-09-05 12:42:46 +00002775
2776
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002777C-level Changes
2778---------------
2779
2780Several cleanup jobs were carried out throughout the source code.
2781
2782All C code was converted to ANSI C; we got rid of all uses of the
2783Py_PROTO() macro, which makes the header files a lot more readable.
2784
2785Most of the portability hacks were moved to a new header file,
2786pyport.h; several other new header files were added and some old
2787header files were removed, in an attempt to create a more rational set
2788of header files. (Few of these ever need to be included explicitly;
2789they are all included by Python.h.)
2790
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002791Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002792and Win64, especially for the new Intel Itanium processor. Mick also
2793added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002794
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002795The C APIs to return an object's size have been update to consistently
2796use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2797previous versions, the abstract interfaces used PyXXX_Length and the
2798concrete interfaces used PyXXX_Size. The old names,
2799e.g. PyObject_Length, are still available for backwards compatibility
2800at the API level, but are deprecated.
2801
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002802The PyOS_CheckStack function has been implemented on Windows by
2803Fredrik Lundh. It prevents Python from failing with a stack overflow
2804on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002805
2806The GC changes resulted in creation of two new slots on object,
2807tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002808the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002809
2810The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002811C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002812
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002813PyErr_Format has been updated to automatically calculate the size of
2814the buffer needed to hold the formatted result string. This change
2815prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002816
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002817New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002818
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002819PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2820that are the same as their non-Ex counterparts except they take an
2821extra flag argument that tells them to close the file when done.
2822
2823XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002824
Tim Peters8b092332000-09-05 20:15:25 +00002825
2826Windows Changes
2827---------------
2828
2829New popen2/popen3/peopen4 in os module (see Changed Modules above).
2830
2831os.popen is much more usable on Windows 95 and 98. See Microsoft
2832Knowledge Base article Q150956. The Win9x workaround described there
2833is implemented by the new w9xpopen.exe helper in the root of your
2834Python installation. Note that Python uses this internally; it is not
2835a standalone program.
2836
2837Administrator privileges are no longer required to install Python
2838on Windows NT or Windows 2000. If you have administrator privileges,
2839Python's registry info will be written under HKEY_LOCAL_MACHINE.
2840Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002841under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002842uses of Python, but will prevent some advanced uses from working
2843(for example, running a Python script as an NT service, or possibly
2844from CGI).
2845
2846[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2847installer; instead, it installs the needed Tcl/Tk files directly in the
2848Python directory. If you already have a Tcl/Tk installation, this
2849wastes some disk space (about 4 Megs) but avoids problems with
2850conflicting Tcl/Tk installations, and makes it much easier for Python
2851to ensure that Tcl/Tk can find all its files.
2852
2853[This was new in 1.6] The Windows installer now installs by default in
2854\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2855
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002856
2857Updates to the changes between 1.5.2 and 1.6
2858--------------------------------------------
2859
2860The 1.6 NEWS file can't be changed after the release is done, so here
2861is some late-breaking news:
2862
2863New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2864and changes to getlocale() and setlocale().
2865
2866The new module is now enabled per default.
2867
2868It is not true that the encodings codecs cannot be used for normal
2869strings: the string.encode() (which is also present on 8-bit strings
2870!) allows using them for 8-bit strings too, e.g. to convert files from
2871cp1252 (Windows) to latin-1 or vice-versa.
2872
2873Japanese codecs are available from Tamito KAJIYAMA:
2874http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2875
2876
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002877======================================================================