blob: 0dfb969a4a8ed3cf50a5b6b1a8266a151814c2b1 [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
Guido van Rossum12d955c2001-10-26 14:56:06 +000035- The socket module defines a new method for socket objects,
36 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +000037 send() until all data has been sent. Also, the socket function has
38 been converted to a subclassable type, like list and tuple (etc.)
39 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +000040
41- Various bugfixes to the curses module. There is now a test suite
42 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000043
Guido van Rossum692adf12001-10-30 03:03:03 +000044- binascii.b2a_base64 no longer places an arbitrary restriction of 57
45 bytes on its input.
46
Tim Peters84362bc2001-10-19 17:55:30 +000047Library
48
Tim Peters98791af2001-10-23 01:59:54 +000049- Traceback objects are now scanned by cyclic garbage collection, so
50 cycles created by casual use of sys.exc_info() no longer cause
51 permanent memory leaks (provided garbage collection is enabled).
52
Guido van Rossum49192142001-10-24 20:51:44 +000053- os.extsep -- a new variable needed by the RISCOS support. It is the
54 separator used by extensions, and is '.' on all platforms except
55 RISCOS, where it is '/'. There is no need to use this variable
56 unless you have a masochistic desire to port your code to RISCOS.
57
Tim Peters84362bc2001-10-19 17:55:30 +000058Tools/Demos
59
60Build
61
62C API
63
Tim Peters1fc240e2001-10-26 05:06:50 +000064- New function PySequence_Fast_GET_SIZE() returns the size of a non-
65 NULL result from PySequence_Fast(), more quickly than calling
66 PySequence_Size().
67
Tim Peters84362bc2001-10-19 17:55:30 +000068New platforms
69
Guido van Rossum86443212001-10-27 22:28:54 +000070- We've finally confirmed that this release builds on HP-UX 11.00,
71 *with* threads, and passes the test suite.
72
Guido van Rossum49192142001-10-24 20:51:44 +000073- Updated RISCOS port by Dietmar Schwertberger.
74
Tim Peters84362bc2001-10-19 17:55:30 +000075Tests
76
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000077- Added a test script for the curses module. It isn't run automatically;
78 regrtest.py must be run with '-u curses' to enable it.
79
Tim Peters84362bc2001-10-19 17:55:30 +000080Windows
81
82
Tim Petersabf925f2001-09-28 21:53:42 +000083What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +000084Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +000085===========================
86
87Type/class unification and new-style classes
88
Guido van Rossum687ae002001-10-15 22:03:32 +000089- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +000090 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +000091 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000092 remains: the __dict__ of a new-style class is a read-only proxy; you
93 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000094 __defined__ attribute of new-style types no longer exists, for lack
95 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000096 future a __cache__ may be resurrected with a similar function, if I
97 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000098
Tim Peters1c9ca872001-10-04 06:43:12 +000099- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
100 always returned None, even when there was a class docstring).
101
102- doctest now finds and runs docstrings attached to new-style classes,
103 class methods, static methods, and properties.
104
Guido van Rossum9074ef62001-10-16 21:34:49 +0000105Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000106
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000107- A very subtle syntactical pitfall in list comprehensions was fixed.
108 For example: [a+b for a in 'abc', for b in 'def']. The comma in
109 this example is a mistake. Previously, this would silently let 'a'
110 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
111 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
112 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
113 Note that [a for a in <singleton>] is a convoluted way to say
114 [<singleton>] anyway, so it's not like any expressiveness is lost.
115
Guido van Rossum9074ef62001-10-16 21:34:49 +0000116- getattr(obj, name, default) now only catches AttributeError, as
117 documented, rather than returning the default value for all
118 exceptions (which could mask bugs in a __getattr__ hook, for
119 example).
120
Fred Drakecb7a6b52001-10-22 18:41:51 +0000121- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000122 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000123 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000124 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000125
Guido van Rossum1c486092001-10-19 02:05:35 +0000126- unicode(obj) now behaves more like str(obj), accepting arbitrary
127 objects, and calling a __unicode__ method if it exists.
128 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000129 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000130
Barry Warsawf6fb1712001-10-19 05:35:40 +0000131- isinstance() now allows any object as the first argument and a
132 class, a type or something with a __bases__ tuple attribute for the
133 second argument. The second argument may also be a tuple of a
134 class, type, or something with __bases__, in which case isinstance()
135 will return true if the first argument is an instance of any of the
136 things contained in the second argument tuple. E.g.
137
138 isinstance(x, (A, B))
139
140 returns true if x is an instance of A or B.
141
Guido van Rossum9074ef62001-10-16 21:34:49 +0000142Extension modules
143
144- thread.start_new_thread() now returns the thread ID (previously None).
145
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000146- binascii has now two quopri support functions, a2b_qp and b2a_qp.
147
Guido van Rossumc524d952001-10-19 01:31:59 +0000148- readline now supports setting the startup_hook and the
149 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000150
Guido van Rossumc524d952001-10-19 01:31:59 +0000151- os and posix supports chroot(), setgroups() and unsetenv() where
152 available. The stat(), fstat(), statvfs() and fstatvfs() functions
153 now return "pseudo-sequences" -- the various fields can now be
154 accessed as attributes (e.g. os.stat("/").st_mtime) but for
155 backwards compatibility they also behave as a fixed-length sequence.
156 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000157 attributes.
158
159- time: localtime(), gmtime() and strptime() now return a
160 pseudo-sequence similar to the os.stat() return value, with
161 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000162
Guido van Rossum9074ef62001-10-16 21:34:49 +0000163- Decompression objects in the zlib module now accept an optional
164 second parameter to decompress() that specifies the maximum amount
165 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000166
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000167- optional SSL support in the socket module now exports OpenSSL
168 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
169 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000170 automatically seed its PRNG. Also, the keyfile and certfile
171 arguments to socket.ssl() are now optional.
172
173- posixmodule (and by extension, the os module on POSIX platforms) now
174 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000175
Guido van Rossum9074ef62001-10-16 21:34:49 +0000176Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000177
Tim Peters7402f792001-10-02 03:53:41 +0000178- doctest now excludes functions and classes not defined by the module
179 being tested, thanks to Tim Hochberg.
180
Fred Drakecb7a6b52001-10-22 18:41:51 +0000181- HotShot, a new profiler implemented using a C-based callback, has
182 been added. This substantially reduces the overhead of profiling,
183 but it is still quite preliminary. Support modules and
184 documentation will be added in upcoming releases (before 2.2 final).
185
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000186- profile now produces correct output in situations where an exception
187 raised in Python is cleared by C code (e.g. hasattr()). This used
188 to cause wrong output, including spurious claims of recursive
189 functions and attribution of time spent to the wrong function.
190
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000191 The code and documentation for the derived OldProfile and HotProfile
192 profiling classes was removed. The code hasn't worked for years (if
193 you tried to use them, they raised exceptions). OldProfile
194 intended to reproduce the behavior of the profiler Python used more
195 than 7 years ago, and isn't interesting anymore. HotProfile intended
196 to provide a faster profiler (but producing less information), and
197 that's a worthy goal we intend to meet via a different approach (but
198 without losing information).
199
Tim Peterscce092d2001-10-09 05:31:56 +0000200- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000201 a much better system-specific calibration constant. The constant can
202 now be specified in an instance constructor, or as a Profile class or
203 instance variable, instead of by editing profile.py's source code.
204 Calibration must still be done manually (see the docs for the profile
205 module).
206
207 Note that Profile.calibrate() must be overriden by subclasses.
208 Improving the accuracy required exploiting detailed knowledge of
209 profiler internals; the earlier method abstracted away the details
210 and measured a simplified model instead, but consequently computed
211 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000212
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000213- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000214 which indicates whether output is intended for the header 'Q'
215 encoding.
216
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000217- The SocketServer.ThreadingMixIn class now closes the request after
218 finish_request() returns. (Not when it errors out though.)
219
Barry Warsawf6fb1712001-10-19 05:35:40 +0000220- The nntplib module's NNTP.body() method has grown a `file' argument
221 to allow saving the message body to a file.
222
223- The email package has added a class email.Parser.HeaderParser which
224 only parses headers and does not recurse into the message's body.
225 Also, the module/class MIMEAudio has been added for representing
226 audio data (contributed by Anthony Baxter).
227
228- ftplib should be able to handle files > 2GB.
229
230- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
231 ON, and OFF.
232
Fred Drakecb7a6b52001-10-22 18:41:51 +0000233- xml.dom.minidom NodeList objects now support the length attribute
234 and item() method as required by the DOM specifications.
235
Guido van Rossumed554f62001-10-02 23:15:37 +0000236Tools/Demos
237
238- Demo/dns was removed. It no longer serves any purpose; a package
239 derived from it is now maintained by Anthony Baxter, see
240 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000241
Barry Warsawf6fb1712001-10-19 05:35:40 +0000242- The freeze tool has been made more robust, and two new options have
243 been added: -X and -E.
244
Tim Petersabf925f2001-09-28 21:53:42 +0000245Build
246
Barry Warsawf6fb1712001-10-19 05:35:40 +0000247- configure will use CXX in LINKCC if CXX is used to build main() and
248 the system requires to link a C++ main using the C++ compiler.
249
Tim Petersabf925f2001-09-28 21:53:42 +0000250C API
251
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000252- The documentation for the tp_compare slot is updated to require that
253 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
254 not correct. This is not yet enforced but will be enforced in
255 Python 2.3; even later, we may use -2 to indicate errors and +2 for
256 "NotImplemented". Right now, -1 should be used for an error return.
257
Tim Petersd38b1c72001-09-30 05:09:37 +0000258- PyLong_AsLongLong() now accepts int (as well as long) arguments.
259 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
260 as long) arguments.
261
Guido van Rossum3c288632001-10-16 21:13:49 +0000262- PyThread_start_new_thread() now returns a long int giving the thread
263 ID, if one can be calculated; it returns -1 for error, 0 if no
264 thread ID is calculated (this is an incompatible change, but only
265 the thread module used this API). This code has only really been
266 tested on Linux and Windows; other platforms please beware (and
267 report any bugs or strange behavior).
268
Guido van Rossum1c486092001-10-19 02:05:35 +0000269- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
270 input.
271
Tim Petersabf925f2001-09-28 21:53:42 +0000272New platforms
273
274Tests
275
276Windows
277
Tim Peters04cf1d32001-10-09 22:39:40 +0000278- Installer: If you install IDLE, and don't disable file-extension
279 registration, a new "Edit with IDLE" context (right-click) menu entry
280 is created for .py and .pyw files.
281
Tim Peters1ce3cf72001-10-01 17:58:40 +0000282- The signal module now supports SIGBREAK on Windows, thanks to Steven
283 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
284 action remains to call Win32 ExitProcess(). This can be changed via
285 signal.signal(). For example:
286
287 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
288 # (SIGINT) behavior.
289 import signal
290 signal.signal(signal.SIGBREAK,
291 signal.default_int_handler)
292
293 try:
294 while 1:
295 pass
296 except KeyboardInterrupt:
297 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
298 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
299 # program without the possibility for any Python-level cleanup).
300 print "Clean exit"
301
Tim Petersabf925f2001-09-28 21:53:42 +0000302
Tim Petersb07352e2001-09-08 01:25:47 +0000303What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000304Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000305===========================
306
Guido van Rossum808eea72001-09-25 04:15:41 +0000307Type/class unification and new-style classes
308
309- pydoc and inspect are now aware of new-style classes;
310 e.g. help(list) at the interactive prompt now shows proper
311 documentation for all operations on list objects.
312
313- Applications using Jim Fulton's ExtensionClass module can now safely
314 be used with Python 2.2. In particular, Zope 2.4.1 now works with
315 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
316 examples also work again. It is hoped that Gtk and Boost also work
317 with 2.2a4 and beyond. (If you can confirm this, please write
318 webmaster@python.org; if there are still problems, please open a bug
319 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000320
Tim Peters66c1a522001-09-24 21:17:50 +0000321- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
322 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
323 in the constructed property object. fget, fset and fdel weren't
324 discoverable from Python in 2.2a3. __doc__ is new, and allows to
325 associate a docstring with a property.
326
Guido van Rossum808eea72001-09-25 04:15:41 +0000327- Comparison overloading is now more completely implemented. For
328 example, a str subclass instance can properly be compared to a str
329 instance, and it can properly overload comparison. Ditto for most
330 other built-in object types.
331
332- The repr() of new-style classes has changed; instead of <type
333 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
334 *except* for built-in types, which are still rendered as <type
335 'Foo'> (to avoid upsetting existing code that might parse or
336 otherwise rely on repr() of certain type objects).
337
338- The repr() of new-style objects is now always <Foo object at XXX>;
339 previously, it was sometimes <Foo instance at XXX>.
340
341- For new-style classes, what was previously called __getattr__ is now
342 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000343 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000344 one in classic classes is defined which is called only if regular
345 attribute access raises AttributeError; to catch *all* attribute
346 access, you can use __getattribute__ (for new-style classes). If
347 both are defined, __getattribute__ is called first, and if it raises
348 AttributeError, __getattr__ is called.
349
350- The __class__ attribute of new-style objects can be assigned to.
351 The new class must have the same C-level object layout as the old
352 class.
353
354- The builtin file type can be subclassed now. In the usual pattern,
355 "file" is the name of the builtin type, and file() is a new builtin
356 constructor, with the same signature as the builtin open() function.
357 file() is now the preferred way to open a file.
358
359- Previously, __new__ would only see sequential arguments passed to
360 the type in a constructor call; __init__ would see both sequential
361 and keyword arguments. This made no sense whatsoever any more, so
362 now both __new__ and __init__ see all arguments.
363
364- Previously, hash() applied to an instance of a subclass of str or
365 unicode always returned 0. This has been repaired.
366
367- Previously, an operation on an instance of a subclass of an
368 immutable type (int, long, float, complex, tuple, str, unicode),
369 where the subtype didn't override the operation (and so the
370 operation was handled by the builtin type), could return that
371 instance instead a value of the base type. For example, if s was of
372 a str sublass type, s[:] returned s as-is. Now it returns a str
373 with the same value as s.
374
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000375- Provisional support for pickling new-style objects has been added.
376
Guido van Rossum808eea72001-09-25 04:15:41 +0000377Core
378
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000379- file.writelines() now accepts any iterable object producing strings.
380
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000381- PyUnicode_FromEncodedObject() now works very much like
382 PyObject_Str(obj) in that it tries to use __str__/tp_str
383 on the object if the object is not a string or buffer. This
384 makes unicode() behave like str() when applied to non-string/buffer
385 objects.
386
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000387- PyFile_WriteObject now passes Unicode objects to the file's write
388 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000389 of a print statement must support Unicode objects, i.e. they must
390 at least convert them into ASCII strings.
391
Guido van Rossum624c8af2001-09-18 15:21:04 +0000392- Thread scheduling on Solaris should be improved; it is no longer
393 necessary to insert a small sleep at the start of a thread in order
394 to let other runnable threads be scheduled.
395
Tim Petersb07352e2001-09-08 01:25:47 +0000396Library
397
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000398- StringIO.StringIO instances and cStringIO.StringIO instances support
399 read character buffer compatible objects for their .write() methods.
400 These objects are converted to strings and then handled as such
401 by the instances.
402
Barry Warsaw2f600732001-09-24 04:28:10 +0000403- The "email" package has been added. This is basically a port of the
404 mimelib package <http://sf.net/projects/mimelib> with API changes
405 and some implementations updated to use iterators and generators.
406
Tim Peters8a9c2842001-09-22 21:30:22 +0000407- difflib.ndiff() and difflib.Differ.compare() are generators now. This
408 restores the ability of Tools/scripts/ndiff.py to start producing output
409 before the entire comparison is complete.
410
Barry Warsaw58b072d2001-09-22 04:44:21 +0000411- StringIO.StringIO instances and cStringIO.StringIO instances support
412 iteration just like file objects (i.e. their .readline() method is
413 called for each iteration until it returns an empty string).
414
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000415- The codecs module has grown four new helper APIs to access
416 builtin codecs: getencoder(), getdecoder(), getreader(),
417 getwriter().
418
Guido van Rossum624c8af2001-09-18 15:21:04 +0000419- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
420 simplifies writing XML RPC servers.
421
Barry Warsaw647d5e82001-09-28 17:01:02 +0000422- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000423 after interpretation of symbolic links. On non-Unix systems, this
424 is an alias for os.path.abspath().
425
Tim Peters16a77ad2001-09-08 04:00:12 +0000426- operator.indexOf() (PySequence_Index() in the C API) now works with any
427 iterable object.
428
Guido van Rossum624c8af2001-09-18 15:21:04 +0000429- smtplib now supports various authentication and security features of
430 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000431
Guido van Rossum624c8af2001-09-18 15:21:04 +0000432- hmac: a new module implementing keyed hashing for message
433 authentication.
434
435- mimetypes now recognizes more extensions and file types. At the
436 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000437
Guido van Rossum624c8af2001-09-18 15:21:04 +0000438- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000439 Python 2.2 bytecode generation. It has also been promoted from a
440 Tool to a standard library package. (Tools/compiler still exists as
441 a sample driver.)
442
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000443Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000444
Tim Petersb07352e2001-09-08 01:25:47 +0000445Build
446
Guido van Rossum624c8af2001-09-18 15:21:04 +0000447- Large file support (LFS) is now automatic when the platform supports
448 it; no more manual configuration tweaks are needed. On Linux, at
449 least, it's possible to have a system whose C library supports large
450 files but whose kernel doesn't; in this case, large file support is
451 still enabled but doesn't do you any good unless you upgrade your
452 kernel or share your Python executable with another system whose
453 kernel has large file support.
454
455- The configure script now supplies plausible defaults in a
456 cross-compilation environment. This doesn't mean that the supplied
457 values are always correct, or that cross-compilation now works
458 flawlessly -- but it's a first step (and it shuts up most of
459 autoconf's warnings about AC_TRY_RUN).
460
461- The Unix build is now a bit less chatty, courtesy of the parser
462 generator. The build is completely silent (except for errors) when
463 using "make -s", thanks to a -q option to setup.py.
464
Tim Petersb07352e2001-09-08 01:25:47 +0000465C API
466
Guido van Rossum624c8af2001-09-18 15:21:04 +0000467- The "structmember" API now supports some new flag bits to deny read
468 and/or write access to attributes in restricted execution mode.
469
Tim Petersb07352e2001-09-08 01:25:47 +0000470New platforms
471
Guido van Rossum624c8af2001-09-18 15:21:04 +0000472- Compaq's iPAQ handheld, running the "familiar" Linux distribution
473 (http://familiar.handhelds.org).
474
Tim Petersb07352e2001-09-08 01:25:47 +0000475Tests
476
Tim Peters8a9c2842001-09-22 21:30:22 +0000477- The "classic" standard tests, which work by comparing stdout to
478 an expected-output file under Lib/test/output/, no longer stop at
479 the first mismatch. Instead the test is run to completion, and a
480 variant of ndiff-style comparison is used to report all differences.
481 This is much easier to understand than the previous style of reporting.
482
483- The unittest-based standard tests now use regrtest's test_main()
484 convention, instead of running as a side-effect of merely being
485 imported. This allows these tests to be run in more natural and
486 flexible ways as unittests, outside the regrtest framework.
487
488- regrtest.py is much better integrated with unittest and doctest now,
489 especially in regard to reporting errors.
490
Tim Petersb07352e2001-09-08 01:25:47 +0000491Windows
492
Guido van Rossum624c8af2001-09-18 15:21:04 +0000493- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000494 that support it (NTFS under Windows 2000). See "What's New in
495 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000496
Tim Petersb07352e2001-09-08 01:25:47 +0000497
Tim Petersedc99312001-08-22 21:36:50 +0000498What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000499Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000500===========================
501
502Core
503
Tim Peters9fffa3e2001-09-04 05:14:19 +0000504- Conversion of long to float now raises OverflowError if the long is too
505 big to represent as a C double.
506
Tim Peters32f453e2001-09-03 08:35:41 +0000507- The 3-argument builtin pow() no longer allows a third non-None argument
508 if either of the first two arguments is a float, or if both are of
509 integer types and the second argument is negative (in which latter case
510 the arguments are converted to float, so this is really the same
511 restriction).
512
Tim Peters5d2b77c2001-09-03 05:47:38 +0000513- The builtin dir() now returns more information, and sometimes much
514 more, generally naming all attributes of an object, and all attributes
515 reachable from the object via its class, and from its class's base
516 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
517 an empty list. In 2.2a3,
518
519 >>> dir([])
520 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
521 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
522 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
523 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
524 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
525 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
526 'reverse', 'sort']
527
528 dir(module) continues to return only the module's attributes, though.
529
Tim Petersbdee63f2001-09-02 03:40:59 +0000530- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000531 than raising OverflowError. This is a partial implementation of PEP
532 237. You can use -Wdefault::OverflowWarning to enable a warning for
533 this situation, and -Werror::OverflowWarning to revert to the old
534 OverflowError exception.
535
Guido van Rossum61c345f2001-09-04 03:26:15 +0000536- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000537 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000538 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
539 -Qold, meaning the / operator has its classic meaning and no
540 warnings are issued. Using -Qwarn issues a run-time warning about
541 all uses of classic division for int and long arguments; -Qwarnall
542 also warns about classic division for float and complex arguments
543 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
544 new division by default, but only in the __main__ module. You can
545 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
546 __main__ module new division, and warns about classic division
547 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000548
Tim Petersbdee63f2001-09-02 03:40:59 +0000549- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000550 long, float, str, unicode, and tuple. (The types complex, list and
551 dictionary can also be subclassed; this was introduced earlier.)
552 Note that restrictions apply when subclassing immutable built-in
553 types: you can only affect the value of the instance by overloading
554 __new__. You can add mutable attributes, and the subclass instances
555 will have a __dict__ attribute, but you cannot change the "value"
556 (as implemented by the base class) of an immutable subclass instance
557 once it is created.
558
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000559- The dictionary constructor now takes an optional argument, a
560 mapping-like object, and initializes the dictionary from its
561 (key, value) pairs.
562
Tim Petersbdee63f2001-09-02 03:40:59 +0000563- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000564 "cooperative super calls" in a multiple inheritance setting. For an
565 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
566
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000567- A new built-in type, property, has been added. This enables the
568 creation of "properties". These are attributes implemented by
569 getter and setter functions (or only one of these for read-only or
570 write-only attributes), without the need to override __getattr__.
571 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000572
Tim Petersbdee63f2001-09-02 03:40:59 +0000573- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000574 liberalized, to allow leading zeroes. Examples of literals now
575 legal that were SyntaxErrors before:
576
577 00.0 0e3 0100j 07.5 00000000000000000008.
578
Tim Petersbdee63f2001-09-02 03:40:59 +0000579- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000580 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
581
Tim Petersedc99312001-08-22 21:36:50 +0000582Library
583
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000584- telnetlib includes symbolic names for the options, and support for
585 setting an option negotiation callback.
586
Tim Petersa40c7932001-09-05 22:36:56 +0000587- The new C standard no longer requires that math libraries set errno to
588 ERANGE on overflow. For platform libraries that exploit this new
589 freedom, Python's overflow-checking was wholly broken. A new overflow-
590 checking scheme attempts to repair that, but may not be reliable on all
591 platforms (C doesn't seem to provide anything both useful and portable
592 in this area anymore).
593
Martin v. Löwis44f86962001-09-05 13:44:54 +0000594- Asynchronous timeout actions are available through the new class
595 threading.Timer.
596
Tim Peters78526162001-09-05 00:53:45 +0000597- math.log and math.log10 now return sensible results for even huge
598 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
599
Tim Petersbdee63f2001-09-02 03:40:59 +0000600- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000601 currently held. See the docs for the imp module.
602
Tim Petersbdee63f2001-09-02 03:40:59 +0000603- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000604 dumps containing ints written on platforms where Python ints are 8 bytes.
605 When read on a box where Python ints are 4 bytes, such values are
606 converted to Python longs.
607
Tim Petersbdee63f2001-09-02 03:40:59 +0000608- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000609 code objects is no longer allowed. This plugs a security hole.
610
Steve Purcell6091cd62001-09-06 16:05:17 +0000611- unittest.TestResult instances no longer store references to tracebacks
612 generated by test failures. This prevents unexpected dangling references
613 to objects that should be garbage collected between tests.
614
Tim Petersedc99312001-08-22 21:36:50 +0000615Tools
616
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000617- Tools/scripts/fixdiv.py has been added which can be used to fix
618 division operators as per PEP 238.
619
Tim Petersedc99312001-08-22 21:36:50 +0000620Build
621
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000622- If you are an adventurous person using Mac OS X you may want to look at
623 Mac/OSX. There is a Makefile there that will build Python as a real Mac
624 application, which can be used for experimenting with Carbon or Cocoa.
625 Discussion of this on pythonmac-sig, please.
626
Tim Peters7eea37e2001-09-04 22:08:56 +0000627C API
628
629- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000630
Tim Peters9fffa3e2001-09-04 05:14:19 +0000631- Note that PyLong_AsDouble can fail! This has always been true, but no
632 callers checked for it. It's more likely to fail now, because overflow
633 errors are properly detected now. The proper way to check:
634
635 double x = PyLong_AsDouble(some_long_object);
636 if (x == -1.0 && PyErr_Occurred()) {
637 /* The conversion failed. */
638 }
639
Tim Petersbdee63f2001-09-02 03:40:59 +0000640- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000641 compile but will not participate in GC. To upgrade an extension
642 module:
643
644 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000645
Neil Schemenauer4042c692001-08-30 15:38:01 +0000646 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
647 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000648
Neil Schemenauer4042c692001-08-30 15:38:01 +0000649 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
650 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000651
Neil Schemenauer4042c692001-08-30 15:38:01 +0000652 - remove PyGC_HEAD_SIZE from object size calculations
653
654 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
655
Tim Petersbdee63f2001-09-02 03:40:59 +0000656- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000657 These can be used safely to construct string objects from a
658 sprintf-style format string (similar to the format string supported
659 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000660
Tim Petersedc99312001-08-22 21:36:50 +0000661New platforms
662
Tim Petersb7da0902001-09-02 23:01:43 +0000663- Stephen Hansen contributed patches sufficient to get a clean compile
664 under Borland C (Windows), but he reports problems running it and ran
665 out of time to complete the port. Volunteers? Expect a MemoryError
666 when importing the types module; this is probably shallow, and
667 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000668
Tim Petersedc99312001-08-22 21:36:50 +0000669Tests
670
671Windows
672
Tim Peters6e13a562001-09-06 00:32:15 +0000673- Large file support is now enabled on Win32 platforms as well as on
674 Win64. This means that, for example, you can use f.tell() and f.seek()
675 to manipulate files larger than 2 gigabytes (provided you have enough
676 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000677 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
678 filesize limit, and large file support makes no difference there.
679 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
680 NTFS has no practical limit on file size, and files of any size can be
681 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000682
Tim Petersbdee63f2001-09-02 03:40:59 +0000683- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000684 points to command.com (patch from Brian Quinlan).
685
Tim Petersedc99312001-08-22 21:36:50 +0000686
Tim Peters20f51a72001-07-21 02:31:40 +0000687What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000688Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000689===========================
690
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000691Build
692
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000693- Tim Peters developed a brand new Windows installer using Wise 8.1,
694 generously donated to us by Wise Solutions.
695
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000696- configure supports a new option --enable-unicode, with the values
697 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
698 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000699
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000700- A new configure option --enable-framework builds a Mac OS X framework,
701 which "make frameworkinstall" will install. This provides a starting
702 point for more mac-like functionality, join pythonmac-sig@python.org
703 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000704
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000705- The NeXT platform is no longer supported.
706
707- The `new' module is now statically linked.
708
Tim Peters0afb6092001-08-15 06:06:44 +0000709Tools
710
711- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000712 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000713 the module docstring for details.
714
Tim Peters20f51a72001-07-21 02:31:40 +0000715Tests
716
Tim Peters5e824c32001-08-12 22:25:01 +0000717- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000718 platforms, allowing to give clearer test result output. regrtest
719 also has optional --use/-u switch to run normally disabled tests
720 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000721
Tim Peters20f51a72001-07-21 02:31:40 +0000722- Several new tests in the standard test suite, with special thanks to
723 Nick Mathewson.
724
725Core
726
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000727- The floor division operator // has been added as outlined in PEP
728 238. The / operator still provides classic division (and will until
729 Python 3.0) unless "from __future__ import division" is included, in
730 which case the / operator will provide true division. The operator
731 module provides truediv() and floordiv() functions. Augmented
732 assignment variants are included, as are the equivalent overloadable
733 methods and C API methods. See the PEP for a full discussion:
734 <http://python.sf.net/peps/pep-0238.html>
735
Tim Peters6cd6a822001-08-17 22:11:27 +0000736- Future statements are now effective in simulated interactive shells
737 (like IDLE). This should "just work" by magic, but read Michael
738 Hudson's "Future statements in simulated shells" PEP 264 for full
739 details: <http://python.sf.net/peps/pep-0264.html>.
740
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000741- The type/class unification (PEP 252-253) was integrated into the
742 trunk and is not so tentative any more (the exact specification of
743 some features is still tentative). A lot of work has done on fixing
744 bugs and adding robustness and features (performance still has to
745 come a long way).
746
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000747- Warnings about a mismatch in the Python API during extension import
748 now use the Python warning framework (which makes it possible to
749 write filters for these warnings).
750
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000751- A function's __dict__ (aka func_dict) will now always be a
752 dictionary. It used to be possible to delete it or set it to None,
753 but now both actions raise TypeErrors. It is still legal to set it
754 to a dictionary object. Getting func.__dict__ before any attributes
755 have been assigned now returns an empty dictionary instead of None.
756
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000757- A new command line option, -E, was added which disables the use of
758 all environment variables, or at least those that are specifically
759 significant to Python. Usually those have a name starting with
760 "PYTHON". This was used to fix a problem where the tests fail if
761 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
762 older distribution.
763
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000764Library
765
Tim Peters5e824c32001-08-12 22:25:01 +0000766- New class Differ and new functions ndiff() and restore() in difflib.py.
767 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000768 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000769
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000770- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
771 value using the minimal quoting required for the value; more
772 reliable than using xml.sax.saxutils.escape() for attribute values.
773
774- Readline completion support for cmd.Cmd was added.
775
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000776- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
777
778- Added function threading.BoundedSemaphore()
779
780- Added Ka-Ping Yee's cgitb.py module.
781
782- The `new' module now exposes the CO_xxx flags.
783
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000784New platforms
785
786C API
787
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000788- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
789 which provide a cross-platform implementations for the
790 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
791 the standard sprintf() and vsprintf() C lib APIs, these versions
792 apply bounds checking on the used buffer which enhances protection
793 against buffer overruns.
794
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000795- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000796 and extensions using different Unicode widths is rendered next to
797 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000798 will result in an ImportError. Unicode extensions writers must make
799 sure to check the Unicode width compatibility in their extensions by
800 using at least one of the mangled Unicode APIs in the extension.
801
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000802- Two new flags METH_NOARGS and METH_O are available in method definition
803 tables to simplify implementation of methods with no arguments and a
804 single untyped argument. Calling such methods is more efficient than
805 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
806 deprecated.
807
Tim Petersc1731372001-08-04 08:12:36 +0000808Windows
809
810- "import module" now compiles module.pyw if it exists and nothing else
811 relevant is found.
812
Tim Peters20f51a72001-07-21 02:31:40 +0000813
Guido van Rossum55a78992001-07-17 17:22:32 +0000814What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +0000815Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +0000816===========================
817
818Core
Tim Petersa814db52001-05-14 07:05:58 +0000819
Tim Peters6d6c1a32001-08-02 04:15:00 +0000820- TENTATIVELY, a large amount of code implementing much of what's
821 described in PEP 252 (Making Types Look More Like Classes) and PEP
822 253 (Subtyping Built-in Types) was added. This will be released
823 with Python 2.2a1. Documentation will be provided separately
824 through http://www.python.org/2.2/. The purpose of releasing this
825 with Python 2.2a1 is to test backwards compatibility. It is
826 possible, though not likely, that a decision is made not to release
827 this code as part of 2.2 final, if any serious backwards
828 incompapatibilities are found during alpha testing that cannot be
829 repaired.
830
Guido van Rossum55a78992001-07-17 17:22:32 +0000831- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000832 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000833 more 'yield' statements. See PEP 255. Since this adds a new
834 keyword to the language, this feature must be enabled by including a
835 future statement: "from __future__ import generators" (see PEP 236).
836 Generators will become a standard feature in a future release
837 (probably 2.3). Without this future statement, 'yield' remains an
838 ordinary identifier, but a warning is issued each time it is used.
839 (These warnings currently don't conform to the warnings framework of
840 PEP 230; we intend to fix this in 2.2a2.)
841
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000842- The UTF-16 codec was modified to be more RFC compliant. It will now
843 only remove BOM characters at the start of the string and then
844 only if running in native mode (UTF-16-LE and -BE won't remove a
845 leading BMO character).
846
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000847- Strings now have a new method .decode() to complement the already
848 existing .encode() method. These two methods provide direct access
849 to the corresponding decoders and encoders of the registered codecs.
850
851 To enhance the usability of the .encode() method, the special
852 casing of Unicode object return values was dropped (Unicode objects
853 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000854
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000855 Both methods will now return whatever the codec in charge of the
856 requested encoding returns as object, e.g. Unicode codecs will
857 return Unicode objects when decoding is requested ("Ă¤Ă¶Ă¼".decode("latin-1")
858 will return u"Ă¤Ă¶Ă¼"). This enables codec writer to create codecs
859 for various simple to use conversions.
860
861 New codecs were added to demonstrate these new features (the .encode()
862 and .decode() columns indicate the type of the returned objects):
863
864 Name | .encode() | .decode() | Description
865 ----------------------------------------------------------------------
866 uu | string | string | UU codec (e.g. for email)
867 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000868 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000869 zlib | string | string | zlib compression
870 hex | string | string | 2-byte hex codec
871 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
872
Mark Hammond2a0af792001-05-14 03:09:36 +0000873- Some operating systems now support the concept of a default Unicode
874 encoding for file system operations. Notably, Windows supports 'mbcs'
875 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000876 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000877 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000878
879 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000880 functions that return filenames (such as os.listdir()) to return Python
881 string objects pre-encoded using the default file system encoding for
882 the platform. As this encoding is likely to be different from Python's
883 default encoding, converting this name to a Unicode object before passing
884 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000885 would attempt to use its default encoding (generally ASCII) rather than
886 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000887
Tim Petersa814db52001-05-14 07:05:58 +0000888 In general, this change simply removes surprises when working with
889 Unicode and the file system, making these operations work as you expect,
890 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000891 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000892
Tim Peters61dff2b2001-05-08 15:43:37 +0000893- Float (and complex) literals in source code were evaluated to full
894 precision only when running from a .py file; the same code loaded from a
895 .pyc (or .pyo) file could suffer numeric differences starting at about the
896 12th significant decimal digit. For example, on a machine with IEEE-754
897 floating arithmetic,
898
899 x = 9007199254740992.0
900 print long(x)
901
902 printed 9007199254740992 if run directly from .py, but 9007199254740000
903 if from a compiled (.pyc or .pyo) file. This was due to marshal using
904 str(float) instead of repr(float) when building code objects. marshal
905 now uses repr(float) instead, which should reproduce floats to full
906 machine precision (assuming the platform C float<->string I/O conversion
907 functions are of good quality).
908
909 This may cause floating-point results to change in some cases, and
910 usually for the better, but may also cause numerically unstable
911 algorithms to break.
912
Tim Peters2f228e72001-05-13 00:19:31 +0000913- The implementation of dicts suffers fewer collisions, which has speed
914 benefits. However, the order in which dict entries appear in dict.keys(),
915 dict.values() and dict.items() may differ from previous releases for a
916 given dict. Nothing is defined about this order, so no program should
917 rely on it. Nevertheless, it's easy to write test cases that rely on the
918 order by accident, typically because of printing the str() or repr() of a
919 dict to an "expected results" file. See Lib/test/test_support.py's new
920 sortdict(dict) function for a simple way to display a dict in sorted
921 order.
922
Tim Peters7a3bfc32001-06-12 01:22:22 +0000923- Many other small changes to dicts were made, resulting in faster
924 operation along the most common code paths.
925
Guido van Rossum10315822001-05-01 20:54:30 +0000926- Dictionary objects now support the "in" operator: "x in dict" means
927 the same as dict.has_key(x).
928
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000929- The update() method of dictionaries now accepts generic mapping
930 objects. Specifically the argument object must support the .keys()
931 and __getitem__() methods. This allows you to say, for example,
932 {}.update(UserDict())
933
Guido van Rossum10315822001-05-01 20:54:30 +0000934- Iterators were added; this is a generalized way of providing values
935 to a for loop. See PEP 234. There's a new built-in function iter()
936 to return an iterator. There's a new protocol to get the next value
937 from an iterator using the next() method (in Python) or the
938 tp_iternext slot (in C). There's a new protocol to get iterators
939 using the __iter__() method (in Python) or the tp_iter slot (in C).
940 Iterating (i.e. a for loop) over a dictionary generates its keys.
941 Iterating over a file generates its lines.
942
Tim Petersf553f892001-05-01 20:45:31 +0000943- The following functions were generalized to work nicely with iterator
944 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000945 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000946 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
947 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000948 join() method of strings
949 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000950 'x in y' and 'x not in y' (PySequence_Contains() in C API)
951 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000952 right-hand side of assignment statements with multiple targets, such as
953 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000954
Tim Petersd85e1022001-05-11 21:51:48 +0000955- Accessing module attributes is significantly faster (for example,
956 random.random or os.path or yourPythonModule.yourAttribute).
957
Tim Peterse63415e2001-05-08 04:38:29 +0000958- Comparing dictionary objects via == and != is faster, and now works even
959 if the keys and values don't support comparisons other than ==.
960
Tim Peters95bf9392001-05-10 08:32:44 +0000961- Comparing dictionaries in ways other than == and != is slower: there were
962 insecurities in the dict comparison implementation that could cause Python
963 to crash if the element comparison routines for the dict keys and/or
964 values mutated the dicts. Making the code bulletproof slowed it down.
965
Tim Peterseb28ef22001-06-02 05:27:19 +0000966- Collisions in dicts are resolved via a new approach, which can help
967 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000968 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000969 faster now. Thanks to Christian Tismer for pointing out the cause and
970 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000971
Tim Peters52e155e2001-06-16 05:42:57 +0000972- repr() is much faster for large containers (dict, list, tuple).
973
974
Tim Petersa814db52001-05-14 07:05:58 +0000975Library
976
Fred Drake960fdf92001-07-20 18:38:26 +0000977- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
978 were added to the string module. These a locale-indenpendent
979 constants, unlike letters, lowercase, and uppercase. These are now
980 use in appropriate locations in the standard library.
981
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000982- The flags used in dlopen calls can now be configured using
983 sys.setdlopenflags and queried using sys.getdlopenflags.
984
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000985- Fredrik Lundh's xmlrpclib is now a standard library module. This
986 provides full client-side XML-RPC support. In addition,
987 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
988 one asyncore-based). Thanks to Eric Raymond for the documentation.
989
Guido van Rossum643d3912001-07-05 14:46:25 +0000990- The xrange() object is simplified: it no longer supports slicing,
991 repetition, comparisons, efficient 'in' checking, the tolist()
992 method, or the start, stop and step attributes. See PEP 260.
993
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000994- A new function fnmatch.filter to filter lists of file names was added.
995
Barry Warsawffd674d2001-05-22 16:00:10 +0000996- calendar.py uses month and day names based on the current locale.
997
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000998- strop is now *really* obsolete (this was announced before with 1.6),
999 and issues DeprecationWarning when used (except for the four items
1000 that are still imported into string.py).
1001
Tim Petersa814db52001-05-14 07:05:58 +00001002- Cookie.py now sorts key+value pairs by key in output strings.
1003
1004- pprint.isrecursive(object) didn't correctly identify recursive objects.
1005 Now it does.
1006
Tim Peters95b3f782001-05-14 18:39:41 +00001007- pprint functions now much faster for large containers (tuple, list, dict).
1008
Tim Peters7b9542a2001-06-10 23:40:19 +00001009- New 'q' and 'Q' format codes in the struct module, corresponding to C
1010 types "long long" and "unsigned long long" (on Windows, __int64). In
1011 native mode, these can be used only when the platform C compiler supports
1012 these types (when HAVE_LONG_LONG is #define'd by the Python config
1013 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001014 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1015 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001016
Guido van Rossum83213cc2001-06-12 16:48:52 +00001017- The site module installs a new built-in function 'help' that invokes
1018 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1019 it displays a message reminding the user to use 'help()' or
1020 'help(object)'.
1021
Tim Petersa814db52001-05-14 07:05:58 +00001022Tests
1023
1024- New test_mutants.py runs dict comparisons where the key and value
1025 comparison operators mutute the dicts randomly during comparison. This
1026 rapidly causes Python to crash under earlier releases (not for the faint
1027 of heart: it can also cause Win9x to freeze or reboot!).
1028
1029- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001030 pprint.isreadable() return sensible results. Also verifies that simple
1031 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001032
Tim Peters4324aa32001-05-28 22:30:08 +00001033C API
1034
1035- Removed the unused last_is_sticky argument from the internal
1036 _PyTuple_Resize(). If this affects you, you were cheating.
1037
1038
Guido van Rossum55a78992001-07-17 17:22:32 +00001039======================================================================
1040
1041
Guido van Rossumffe13be2001-04-16 18:46:45 +00001042What's New in Python 2.1 (final)?
1043=================================
1044
1045We only changed a few things since the last release candidate, all in
1046Python library code:
1047
1048- A bug in the locale module was fixed that affected locales which
1049 define no grouping for numeric formatting.
1050
1051- A few bugs in the weakref module's implementations of weak
1052 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1053 and the test suite was updated to check for these bugs.
1054
1055- An old bug in the os.path.walk() function (introduced in Python
1056 2.0!) was fixed: a non-existent file would cause an exception
1057 instead of being ignored.
1058
1059- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1060 PyChecker.
1061
1062
Guido van Rossum5b08f132001-04-16 02:05:23 +00001063What's New in Python 2.1c2?
1064===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001065
Guido van Rossum5b08f132001-04-16 02:05:23 +00001066A flurry of small changes, and one showstopper fixed in the nick of
1067time made it necessary to release another release candidate. The list
1068here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001069
Guido van Rossum5b08f132001-04-16 02:05:23 +00001070Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001071
Guido van Rossum5b08f132001-04-16 02:05:23 +00001072- Tim discovered a nasty bug in the dictionary code, caused by
1073 PyDict_Next() calling dict_resize(), and the GC code's use of
1074 PyDict_Next() violating an assumption in dict_items(). This was
1075 fixed with considerable amounts of band-aid, but the net effect is a
1076 saner and more robust implementation.
1077
1078- Made a bunch of symbols static that were accidentally global.
1079
1080Build and Ports
1081
1082- The setup.py script didn't check for a new enough version of zlib
1083 (1.1.3 is needed). Now it does.
1084
1085- Changed "make clean" target to also remove shared libraries.
1086
1087- Added a more general warning about the SGI Irix optimizer to README.
1088
1089Library
1090
1091- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1092 omitted the slash between host and file.html.
1093
1094- The mailbox module's _Mailbox class contained a completely broken
1095 and undocumented seek() method. Ripped it out.
1096
1097- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1098 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1099
1100- Fixed a few last-minute bugs in unittest.
1101
1102Extensions
1103
1104- Reverted the patch to the OpenSSL code in socketmodule.c to support
1105 RAND_status() and the EGD, and the subsequent patch that tried to
1106 fix it for pre-0.9.5 versions; the problem with the patch is that on
1107 some systems it issues a warning whenever socket is imported, and
1108 that's unacceptable.
1109
1110Tests
1111
1112- Fixed the pickle tests to work with "import test.test_pickle".
1113
1114- Tweaked test_locale.py to actually run the test Windows.
1115
1116- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1117 not "wb" (which is not a valid mode at all).
1118
1119- Fix pstats browser crashes. Import readline if it exists to make
1120 the user interface nicer.
1121
1122- Add "import thread" to the top of test modules that import the
1123 threading module (test_asynchat and test_threadedtempfile). This
1124 prevents test failures caused by a broken threading module resulting
1125 from a previously caught failed import.
1126
1127- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1128 needed on some platforms (e.g. Solaris 8) when the tests are run
1129 twice in succession.
1130
1131- Skip rather than fail test_sunaudiodev if no audio device is found.
1132
1133
1134What's New in Python 2.1c1?
1135===========================
1136
1137This list was significantly updated when 2.1c2 was released; the 2.1c1
1138release didn't mention most changes that were actually part of 2.1c1:
1139
1140Legal
1141
1142- Copyright was assigned to the Python Software Foundation (PSF) and a
1143 PSF license (very similar to the CNRI license) was added.
1144
1145- The CNRI copyright notice was updated to include 2001.
1146
1147Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001148
Guido van Rossumc9932722001-04-12 02:31:27 +00001149- After a public outcry, assignment to __debug__ is no longer illegal;
1150 instead, a warning is issued. It will become illegal in 2.2.
1151
Guido van Rossum5b08f132001-04-16 02:05:23 +00001152- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1153 "%#x" now always prepends "0x", even if the value is zero.
1154
1155- Fixed some nits in the bytecode compiler.
1156
1157- Fixed core dumps when calling certain kinds of non-functions.
1158
1159- Fixed various core dumps caused by reference count bugs.
1160
1161Build and Ports
1162
1163- Use INSTALL_SCRIPT to install script files.
1164
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001165- New port: SCO Unixware 7, by Billy G. Allie.
1166
Guido van Rossum5b08f132001-04-16 02:05:23 +00001167- Updated RISCOS port.
1168
1169- Updated BeOS port and notes.
1170
1171- Various other porting problems resolved.
1172
1173Library
1174
1175- The TERMIOS and SOCKET modules are now truly obsolete and
1176 unnecessary. Their symbols are incorporated in the termios and
1177 socket modules.
1178
1179- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1180 better tests for pickling.
1181
1182- threading: make Condition.wait() robust against KeyboardInterrupt.
1183
1184- zipfile: add support to zipfile to support opening an archive
1185 represented by an open file rather than a file name. Fix bug where
1186 the archive was not properly closed. Fixed a bug in this bugfix
1187 where flush() was called for a read-only file.
1188
1189- imputil: added an uninstall() method to the ImportManager.
1190
1191- Canvas: fixed bugs in lower() and tkraise() methods.
1192
1193- SocketServer: API change (added overridable close_request() method)
1194 so that the TCP server can explicitly close the request.
1195
1196- pstats: Eric Raymond added a simple interactive statistics browser,
1197 invoked when the module is run as a script.
1198
1199- locale: fixed a problem in format().
1200
1201- webbrowser: made it work when the BROWSER environment variable has a
1202 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1203 KDE 2. Fixed some other nits.
1204
1205- unittest: changes to allow using a different exception than
1206 AssertionError, and added a few more function aliases. Some other
1207 small changes.
1208
1209- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1210
1211- asynchat: fixed a critical bug in asynchat that slipped through the
1212 2.1b2 release. Fixed another rare bug.
1213
1214- Fix some unqualified except: clauses (always a bad code example).
1215
1216XML
1217
1218- pyexpat: new API get_version_string().
1219
1220- Fixed some minidom bugs.
1221
1222Extensions
1223
1224- Fixed a core dump in _weakref. Removed the weakref.mapping()
1225 function (it adds nothing to the API).
1226
1227- Rationalized the use of header files in the readline module, to make
1228 it compile (albeit with some warnings) with the very recent readline
1229 4.2, without breaking for earlier versions.
1230
1231- Hopefully fixed a buffering problem in linuxaudiodev.
1232
1233- Attempted a fix to make the OpenSSL support in the socket module
1234 work again with pre-0.9.5 versions of OpenSSL.
1235
1236Tests
1237
1238- Added a test case for asynchat and asyncore.
1239
1240- Removed coupling between tests where one test failing could break
1241 another.
1242
1243Tools
1244
1245- Ping added an interactive help browser to pydoc, fixed some nits
1246 in the rest of the pydoc code, and added some features to his
1247 inspect module.
1248
1249- An updated python-mode.el version 4.1 which integrates Ken
1250 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1251 much nicer in XEmacs and Emacs. When stepping through your program
1252 with pdb, in either the shell window or the *Python* window, the
1253 source file and line will be tracked by an arrow. Very cool!
1254
1255- IDLE: syntax warnings in interactive mode are changed into errors.
1256
1257- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001258 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001259
1260- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001261
Barry Warsaw11e89c72001-04-11 20:37:57 +00001262
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001263What's New in Python 2.1 beta 2?
1264================================
1265
Guido van Rossum053ae352001-03-22 14:17:21 +00001266(Unlisted are many fixed bugs, more documentation, etc.)
1267
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001268Core language, builtins, and interpreter
1269
Guido van Rossum053ae352001-03-22 14:17:21 +00001270- The nested scopes work (enabled by "from __future__ import
1271 nested_scopes") is completed; in particular, the future now extends
1272 into code executed through exec, eval() and execfile(), and into the
1273 interactive interpreter.
1274
1275- When calling a base class method (e.g. BaseClass.__init__(self)),
1276 this is now allowed even if self is not strictly spoken a class
1277 instance (e.g. when using metaclasses or the Don Beaudry hook).
1278
1279- Slice objects are now comparable but not hashable; this prevents
1280 dict[:] from being accepted but meaningless.
1281
1282- Complex division is now calculated using less braindead algorithms.
1283 This doesn't change semantics except it's more likely to give useful
1284 results in extreme cases. Complex repr() now uses full precision
1285 like float repr().
1286
1287- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1288
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001289- It is illegal to assign to the name __debug__, which is set when the
1290 interpreter starts. It is effectively a compile-time constant.
1291
1292- A warning will be issued if a global statement for a variable
1293 follows a use or assignment of that variable.
1294
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001295Standard library
1296
Guido van Rossum053ae352001-03-22 14:17:21 +00001297- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1298 inspired by JUnit), is now part of the standard library. You now
1299 have a choice of two testing frameworks: unittest requires you to
1300 write testcases as separate code, doctest gathers them from
1301 docstrings. Both approaches have their advantages and
1302 disadvantages.
1303
1304- A new module Tix was added, which wraps the Tix extension library
1305 for Tk. With that module, it is not necessary to statically link
1306 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1307 require" command. See Demo/tix/.
1308
1309- tzparse.py is now obsolete.
1310
1311- In gzip.py, the seek() and tell() methods are removed -- they were
1312 non-functional anyway, and it's better if callers can test for their
1313 existence with hasattr().
1314
1315Python/C API
1316
1317- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1318 that's already in the dictionary during a PyDict_Next() iteration.
1319 This used to fail occasionally when a dictionary resize operation
1320 could be triggered that would rehash all the keys. All other
1321 modifications to the dictionary are still off-limits during a
1322 PyDict_Next() iteration!
1323
1324- New extended APIs related to passing compiler variables around.
1325
1326- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1327 implement isinstance() and issubclass().
1328
1329- Py_BuildValue() now has a "D" conversion to create a Python complex
1330 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001331
Fred Drake4e262a92001-03-22 18:26:47 +00001332- Extensions types which support weak references must now set the
1333 field allocated for the weak reference machinery to NULL themselves;
1334 this is done to avoid the cost of checking each object for having a
1335 weakly referencable type in PyObject_INIT(), since most types are
1336 not weakly referencable.
1337
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001338- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1339 free variables and cell variables to and from the frame's f_locals.
1340
1341- Variants of several functions defined in pythonrun.h have been added
1342 to support the nested_scopes future statement. The variants all end
1343 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1344 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1345 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001346 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001347
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001348Distutils
1349
1350- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1351 into the release tree.
1352
Tim Peters0e57abf2001-05-02 07:39:38 +00001353- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001354 (an uninstaller, more customization of the installer's display)
1355
1356- from Jack Jansen: added Mac-specific code to generate a dialog for
1357 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001358 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001359 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001360
1361- added 'platforms' and 'keywords' to the set of metadata that can be
1362 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001363
1364- applied patches from Jason Tishler to make the compiler class work with
1365 Cygwin.
1366
1367
Tim Peters2fe289a2001-03-01 22:19:38 +00001368What's New in Python 2.1 beta 1?
1369================================
Tim Petersd66595f2001-02-04 03:09:53 +00001370
1371Core language, builtins, and interpreter
1372
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001373- Following an outcry from the community about the amount of code
1374 broken by the nested scopes feature introduced in 2.1a2, we decided
1375 to make this feature optional, and to wait until Python 2.2 (or at
1376 least 6 months) to make it standard. The option can be enabled on a
1377 per-module basis by adding "from __future__ import nested_scopes" at
1378 the beginning of a module (before any other statements, but after
1379 comments and an optional docstring). See PEP 236 (Back to the
1380 __future__) for a description of the __future__ statement. PEP 227
1381 (Statically Nested Scopes) has been updated to reflect this change,
1382 and to clarify the semantics in a number of endcases.
1383
1384- The nested scopes code, when enabled, has been hardened, and most
1385 bugs and memory leaks in it have been fixed.
1386
1387- Compile-time warnings are now generated for a number of conditions
1388 that will break or change in meaning when nested scopes are enabled:
1389
1390 - Using "from...import *" or "exec" without in-clause in a function
1391 scope that also defines a lambda or nested function with one or
1392 more free (non-local) variables. The presence of the import* or
1393 bare exec makes it impossible for the compiler to determine the
1394 exact set of local variables in the outer scope, which makes it
1395 impossible to determine the bindings for free variables in the
1396 inner scope. To avoid the warning about import *, change it into
1397 an import of explicitly name object, or move the import* statement
1398 to the global scope; to avoid the warning about bare exec, use
1399 exec...in... (a good idea anyway -- there's a possibility that
1400 bare exec will be deprecated in the future).
1401
1402 - Use of a global variable in a nested scope with the same name as a
1403 local variable in a surrounding scope. This will change in
1404 meaning with nested scopes: the name in the inner scope will
1405 reference the variable in the outer scope rather than the global
1406 of the same name. To avoid the warning, either rename the outer
1407 variable, or use a global statement in the inner function.
1408
Neil Schemenauera35c6882001-02-27 04:45:05 +00001409- An optional object allocator has been included. This allocator is
1410 optimized for Python objects and should be faster and use less memory
1411 than the standard system allocator. It is not enabled by default
1412 because of possible thread safety problems. The allocator is only
1413 protected by the Python interpreter lock and it is possible that some
1414 extension modules require a thread safe allocator. The object
1415 allocator can be enabled by providing the "--with-pymalloc" option to
1416 configure.
1417
Tim Petersd66595f2001-02-04 03:09:53 +00001418Standard library
1419
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001420- pyexpat now detects the expat version if expat.h defines it. A
1421 number of additional handlers are provided, which are only available
1422 since expat 1.95. In addition, the methods SetParamEntityParsing and
1423 GetInputContext of Parser objects are available with 1.95.x
1424 only. Parser objects now provide the ordered_attributes and
1425 specified_attributes attributes. A new module expat.model was added,
1426 which offers a number of additional constants if 1.95.x is used.
1427
1428- xml.dom offers the new functions registerDOMImplementation and
1429 getDOMImplementation.
1430
1431- xml.dom.minidom offers a toprettyxml method. A number of DOM
1432 conformance issues have been resolved. In particular, Element now
1433 has an hasAttributes method, and the handling of namespaces was
1434 improved.
1435
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001436- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1437 getting information about live Python code, and pydoc.py, a module
1438 for interactively converting docstrings to HTML or text.
1439 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001440 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001441 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1442 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001443
Tim Peters1eff7962001-03-01 02:31:33 +00001444- New library module difflib.py, primarily packaging the SequenceMatcher
1445 class at the heart of the popular ndiff.py file-comparison tool.
1446
1447- doctest.py (a framework for verifying Python code examples in docstrings)
1448 is now part of the std library.
1449
Tim Petersd66595f2001-02-04 03:09:53 +00001450Windows changes
1451
Guido van Rossume3955a82001-03-02 14:05:59 +00001452- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1453 small GUI that lets you browse the module docstrings using your
1454 default web browser.
1455
Tim Peters1eff7962001-03-01 02:31:33 +00001456- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1457 Platforms) is implemented. See
1458
1459 http://python.sourceforge.net/peps/pep-0235.html
1460
1461 for full details, especially the "Current Lower-Left Semantics" section.
1462 The new Windows import rules are simpler than before:
1463
1464 A. If the PYTHONCASEOK environment variable exists, same as
1465 before: silently accept the first case-insensitive match of any
1466 kind; raise ImportError if none found.
1467
1468 B. Else search sys.path for the first case-sensitive match; raise
1469 ImportError if none found.
1470
1471 The same rules have been implented on other platforms with case-
1472 insensitive but case-preserving filesystems too (including Cygwin, and
1473 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001474
Tim Peters25a9ce32001-02-19 07:06:36 +00001475- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1476 what it's supposed to do (and does do under NT and 2000) via direct
1477 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001478 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001479 all Win9x systems before.
1480
Tim Peters1eff7962001-03-01 02:31:33 +00001481- Build: Subproject _test (effectively) renamed to _testcapi.
1482
Tim Peters2fe289a2001-03-01 22:19:38 +00001483New platforms
1484
1485- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1486 Thanks to Steven Majewski!
1487
1488- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1489 Tishler!
1490
Guido van Rossum9089b272001-03-02 06:49:50 +00001491- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1492 Schwertberger! See RISCOS/README for more information -- it seems
1493 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001494 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001495
Tim Peters25a9ce32001-02-19 07:06:36 +00001496
Tim Petersd7b5e882001-01-25 03:36:26 +00001497What's New in Python 2.1 alpha 2?
1498=================================
Tim Peters40ead762001-01-27 05:35:26 +00001499
Tim Petersd7b5e882001-01-25 03:36:26 +00001500Core language, builtins, and interpreter
1501
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001502- Scopes nest. If a name is used in a function or class, but is not
1503 local, the definition in the nearest enclosing function scope will
1504 be used. One consequence of this change is that lambda statements
1505 could reference variables in the namespaces where the lambda is
1506 defined. In some unusual cases, this change will break code.
1507
1508 In all previous version of Python, names were resolved in exactly
1509 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001510 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001511 function A is defined within a function B, the names bound in B are
1512 not visible in A. The new rules make names bound in B visible in A,
1513 unless A contains a name binding that hides the binding in B.
1514
1515 Section 4.1 of the reference manual describes the new scoping rules
1516 in detail. The test script in Lib/test/test_scope.py demonstrates
1517 some of the effects of the change.
1518
1519 The new rules will cause existing code to break if it defines nested
1520 functions where an outer function has local variables with the same
1521 name as globals or builtins used by the inner function. Example:
1522
1523 def munge(str):
1524 def helper(x):
1525 return str(x)
1526 if type(str) != type(''):
1527 str = helper(str)
1528 return str.strip()
1529
1530 Under the old rules, the name str in helper() is bound to the
1531 builtin function str(). Under the new rules, it will be bound to
1532 the argument named str and an error will occur when helper() is
1533 called.
1534
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001535- The compiler will report a SyntaxError if "from ... import *" occurs
1536 in a function or class scope. The language reference has documented
1537 that this case is illegal, but the compiler never checked for it.
1538 The recent introduction of nested scope makes the meaning of this
1539 form of name binding ambiguous. In a future release, the compiler
1540 may allow this form when there is no possibility of ambiguity.
1541
Tim Peters40ead762001-01-27 05:35:26 +00001542- repr(string) is easier to read, now using hex escapes instead of octal,
1543 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1544
1545 >>> "\texample \r\n" + chr(0) + chr(255)
1546 '\texample \r\n\x00\xff' # in 2.1
1547 '\011example \015\012\000\377' # in 2.0
1548
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001549- Functions are now compared and hashed by identity, not by value, since
1550 the func_code attribute is writable.
1551
Fred Drakefb9d7122001-02-01 20:00:40 +00001552- Weak references (PEP 205) have been added. This involves a few
1553 changes in the core, an extension module (_weakref), and a Python
1554 module (weakref). The weakref module is the public interface. It
1555 includes support for "explicit" weak references, proxy objects, and
1556 mappings with weakly held values.
1557
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001558- A 'continue' statement can now appear in a try block within the body
1559 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001560 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001561
Tim Petersd7b5e882001-01-25 03:36:26 +00001562Standard library
1563
Barry Warsaw30dbd142001-01-31 22:14:01 +00001564- mailbox.py now has a new class, PortableUnixMailbox which is
1565 identical to UnixMailbox but uses a more portable scheme for
1566 determining From_ separators. Also, the constructors for all the
1567 classes in this module have a new optional `factory' argument, which
1568 is a callable used when new message classes must be instantiated by
1569 the next() method.
1570
Tim Petersd7b5e882001-01-25 03:36:26 +00001571- random.py is now self-contained, and offers all the functionality of
1572 the now-deprecated whrandom.py. See the docs for details. random.py
1573 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001574 and restoring the internal state of the generator; and jumpahead(n),
1575 for quickly forcing the internal state to be the same as if n calls to
1576 random() had been made. The latter is particularly useful for multi-
1577 threaded programs, creating one instance of the random.Random() class for
1578 each thread, then using .jumpahead() to force each instance to use a
1579 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001580
Tim Peters0de88fc2001-02-01 04:59:18 +00001581- random.py's seed() function is new. For bit-for-bit compatibility with
1582 prior releases, use the whseed function instead. The new seed function
1583 addresses two problems: (1) The old function couldn't produce more than
1584 about 2**24 distinct internal states; the new one about 2**45 (the best
1585 that can be done in the Wichmann-Hill generator). (2) The old function
1586 sometimes produced identical internal states when passed distinct
1587 integers, and there was no simple way to predict when that would happen;
1588 the new one guarantees to produce distinct internal states for all
1589 arguments in [0, 27814431486576L).
1590
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001591- The socket module now supports raw packets on Linux. The socket
1592 family is AF_PACKET.
1593
Tim Peters9ea17ac2001-02-02 05:57:15 +00001594- test_capi.py is a start at running tests of the Python C API. The tests
1595 are implemented by the new Modules/_testmodule.c.
1596
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001597- A new extension module, _symtable, provides provisional access to the
1598 internal symbol table used by the Python compiler. A higher-level
1599 interface will be added on top of _symtable in a future release.
1600
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001601- Removed the obsolete soundex module.
1602
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001603- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1604 the isSameNode method; NamedNodeMap the get method.
1605
1606- xml.sax.expatreader supports the lexical handler property; it
1607 generates comment, startCDATA, and endCDATA events.
1608
Tim Petersee826f82001-01-31 19:39:44 +00001609Windows changes
1610
1611- Build procedure: the zlib project is built in a different way that
1612 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001613 the zlib binary used. See PCbuild\readme.txt for details. Your old
1614 zlib-related directories can be deleted; you'll need to download fresh
1615 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001616
Tim Peters9ea17ac2001-02-02 05:57:15 +00001617- Build: New subproject _test for the benefit of test_capi.py (see above).
1618
Tim Petersb16c56f2001-02-02 21:24:51 +00001619- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1620 interface to some Python compiler internals).
1621
1622- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001623 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001624
Tim Petersa3a3a032000-11-30 05:22:44 +00001625What's New in Python 2.1 alpha 1?
1626=================================
1627
1628Core language, builtins, and interpreter
1629
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001630- There is a new Unicode companion to the PyObject_Str() API
1631 called PyObject_Unicode(). It behaves in the same way as the
1632 former, but assures that the returned value is an Unicode object
1633 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001634
Guido van Rossumf98eda02001-01-17 15:54:45 +00001635- The comparison operators support "rich comparison overloading" (PEP
1636 207). C extension types can provide a rich comparison function in
1637 the new tp_richcompare slot in the type object. The cmp() function
1638 and the C function PyObject_Compare() first try the new rich
1639 comparison operators before trying the old 3-way comparison. There
1640 is also a new C API PyObject_RichCompare() (which also falls back on
1641 the old 3-way comparison, but does not constrain the outcome of the
1642 rich comparison to a Boolean result).
1643
1644 The rich comparison function takes two objects (at least one of
1645 which is guaranteed to have the type that provided the function) and
1646 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1647 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1648 object, which may be NotImplemented (in which case the tp_compare
1649 slot function is used as a fallback, if defined).
1650
1651 Classes can overload individual comparison operators by defining one
1652 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001653 __ge__. There are no explicit "reflected argument" versions of
1654 these; instead, __lt__ and __gt__ are each other's reflection,
1655 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1656 reflection (similar at the C level). No other implications are
1657 made; in particular, Python does not assume that == is the Boolean
1658 inverse of !=, or that < is the Boolean inverse of >=. This makes
1659 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001660
1661 Classes or types that want to implement (in)equality tests but not
1662 the ordering operators (i.e. unordered types) should implement ==
1663 and !=, and raise an error for the ordering operators.
1664
Guido van Rossuma88479f2001-01-18 14:28:08 +00001665 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001666 Boolean; e.g. a matrix type might want to return a matrix of bits
1667 for A < B, giving elementwise comparisons. Such types should ensure
1668 that any interpretation of their value in a Boolean context raises
1669 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1670 at the C level) to always raise an exception.
1671
Guido van Rossuma88479f2001-01-18 14:28:08 +00001672- Complex numbers use rich comparisons to define == and != but raise
1673 an exception for <, <=, > and >=. Unfortunately, this also means
1674 that cmp() of two complex numbers raises an exception when the two
1675 numbers differ. Since it is not mathematically meaningful to compare
1676 complex numbers except for equality, I hope that this doesn't break
1677 too much code.
1678
Tim Peters3389f192001-02-18 08:48:49 +00001679- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001680 not defined by the language, other than that it's arbitrary but
1681 consistent (see the Reference Manual). An implementation detail changed
1682 in 2.1a1 such that None now compares less than any other object. Code
1683 relying on this new behavior (like code that relied on the previous
1684 behavior) does so at its own risk.
1685
Barry Warsaw573b5412001-01-15 20:43:18 +00001686- Functions and methods now support getting and setting arbitrarily
1687 named attributes (PEP 232). Functions have a new __dict__
1688 (a.k.a. func_dict) which hold the function attributes. Methods get
1689 and set attributes on their underlying im_func. It is a TypeError
1690 to set an attribute on a bound method.
1691
Guido van Rossum051e3352001-01-15 19:11:10 +00001692- The xrange() object implementation has been improved so that
1693 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1694 limitation that in this case len(xrange(sys.maxint)) can't be
1695 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1696 work fine as long as the index i doesn't actually reach 2**31.
1697 (Python uses regular ints for sequence and string indices; fixing
1698 that is much more work.)
1699
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001700- Two changes to from...import:
1701
Guido van Rossumba381232001-02-03 15:06:40 +00001702 1) "from M import X" now works even if (after loading module M)
1703 sys.modules['M'] is not a real module; it's basically a getattr()
1704 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001705
1706 2) "from M import *" now looks for M.__all__ to decide which names to
1707 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1708 filters out names starting with '_' as before. Whether or not
1709 __all__ exists, there's no restriction on the type of M.
1710
Guido van Rossumf61f1662001-01-10 20:13:55 +00001711- File objects have a new method, xreadlines(). This is the fastest
1712 way to iterate over all lines in a file:
1713
1714 for line in file.xreadlines():
1715 ...do something to line...
1716
1717 See the xreadlines module (mentioned below) for how to do this for
1718 other file-like objects.
1719
1720- Even if you don't use file.xreadlines(), you may expect a speedup on
1721 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001722 quite a bit in platform-specific ways: on systems (like Linux) that
1723 support flockfile(), getc_unlocked(), and funlockfile(), those are
1724 used by default. On systems (like Windows) without getc_unlocked(),
1725 a complicated (but still thread-safe) method using fgets() is used by
1726 default.
1727
Tim Petersd52269b2001-01-25 06:23:18 +00001728 You can force use of the fgets() method by #define'ing
1729 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001730 getc_unlocked()).
1731
Tim Petersd52269b2001-01-25 06:23:18 +00001732 You can force fgets() not to be used by #define'ing
1733 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001734 test_bufio.py fails -- and let us know if it does!).
1735
1736- In addition, the fileinput module, while still slower than the other
1737 methods on most platforms, has been sped up too, by using
1738 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001739
1740- Support for run-time warnings has been added, including a new
1741 command line option (-W) to specify the disposition of warnings.
1742 See the description of the warnings module below.
1743
1744- Extensive changes have been made to the coercion code. This mostly
1745 affects extension modules (which can now implement mixed-type
1746 numerical operators without having to use coercion), but
1747 occasionally, in boundary cases the coercion semantics have changed
1748 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001749 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001750 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001751 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001752
Guido van Rossumf98eda02001-01-17 15:54:45 +00001753- In connection with the coercion changes, a new built-in singleton
1754 object, NotImplemented is defined. This can be returned for
1755 operations that wish to indicate they are not implemented for a
1756 particular combination of arguments. From C, this is
1757 Py_NotImplemented.
1758
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001759- The interpreter accepts now bytecode files on the command line even
1760 if they do not have a .pyc or .pyo extension. On Linux, after executing
1761
Martin v. Löwise214baa2001-02-04 22:37:56 +00001762import imp,sys,string
1763magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1764reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1765open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001766
1767 any byte code file can be used as an executable (i.e. as an argument
1768 to execve(2)).
1769
Tim Peters9940b802000-12-01 07:59:35 +00001770- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001771 character. In 1.6 and earlier, they never produced a sign,
1772 and raised an error if the value of the long was too large
1773 to fit in a Python int. In 2.0, they produced a sign if and
1774 only if too large to fit in an int. This was inconsistent
1775 across platforms (because the size of an int varies across
1776 platforms), and inconsistent with hex() and oct(). Example:
1777
1778 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001779 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001780 'ffffffbe' # in 2.0 and before, on 32-bit machines
1781 >>> hex(-0x42L)
1782 '-0x42L' # in all versions of Python
1783
Tim Peters9940b802000-12-01 07:59:35 +00001784 The behavior of %d formats for negative Python longs remains
1785 the same as in 2.0 (although in 1.6 and before, they raised
1786 an error if the long didn't fit in a Python int).
1787
1788 %u formats don't make sense for Python longs, but are allowed
1789 and treated the same as %d in 2.1. In 2.0, a negative long
1790 formatted via %u produced a sign if and only if too large to
1791 fit in an int. In 1.6 and earlier, a negative long formatted
1792 via %u raised an error if it was too big to fit in an int.
1793
Guido van Rossum3661d392000-12-12 22:10:31 +00001794- Dictionary objects have an odd new method, popitem(). This removes
1795 an arbitrary item from the dictionary and returns it (in the form of
1796 a (key, value) pair). This can be useful for algorithms that use a
1797 dictionary as a bag of "to do" items and repeatedly need to pick one
1798 item. Such algorithms normally end up running in quadratic time;
1799 using popitem() they can usually be made to run in linear time.
1800
Tim Peters36cdad12000-12-29 02:06:45 +00001801Standard library
1802
Thomas Woutersfe385252001-01-19 23:16:56 +00001803- In the time module, the time argument to the functions strftime,
1804 localtime, gmtime, asctime and ctime is now optional, defaulting to
1805 the current time (in the local timezone).
1806
Guido van Rossumda91f222001-01-15 16:36:08 +00001807- The ftplib module now defaults to passive mode, which is deemed a
1808 more useful default given that clients are often inside firewalls
1809 these days. Note that this could break if ftplib is used to connect
1810 to a *server* that is inside a firewall, from outside; this is
1811 expected to be a very rare situation. To fix that, you can call
1812 ftp.set_pasv(0).
1813
Martin v. Löwis10a27872001-01-13 09:54:41 +00001814- The module site now treats .pth files not only for path configuration,
1815 but also supports extensions to the initialization code: Lines starting
1816 with import are executed.
1817
Guido van Rossumf61f1662001-01-10 20:13:55 +00001818- There's a new module, warnings, which implements a mechanism for
1819 issuing and filtering warnings. There are some new built-in
1820 exceptions that serve as warning categories, and a new command line
1821 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1822 turns warnings into errors). warnings.warn(message[, category])
1823 issues a warning message; this can also be called from C as
1824 PyErr_Warn(category, message).
1825
1826- A new module xreadlines was added. This exports a single factory
1827 function, xreadlines(). The intention is that this code is the
1828 absolutely fastest way to iterate over all lines in an open
1829 file(-like) object:
1830
1831 import xreadlines
1832 for line in xreadlines.xreadlines(file):
1833 ...do something to line...
1834
1835 This is equivalent to the previous the speed record holder using
1836 file.readlines(sizehint). Note that if file is a real file object
1837 (as opposed to a file-like object), this is equivalent:
1838
1839 for line in file.xreadlines():
1840 ...do something to line...
1841
Tim Peters36cdad12000-12-29 02:06:45 +00001842- The bisect module has new functions bisect_left, insort_left,
1843 bisect_right and insort_right. The old names bisect and insort
1844 are now aliases for bisect_right and insort_right. XXX_right
1845 and XXX_left methods differ in what happens when the new element
1846 compares equal to one or more elements already in the list: the
1847 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001848 right. Code that doesn't care where equal elements end up should
1849 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001850
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001851- The new curses.panel module wraps the panel library that forms part
1852 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1853
Guido van Rossumf61f1662001-01-10 20:13:55 +00001854- The SocketServer module now sets the allow_reuse_address flag by
1855 default in the TCPServer class.
1856
1857- A new function, sys._getframe(), returns the stack frame pointer of
1858 the caller. This is intended only as a building block for
1859 higher-level mechanisms such as string interpolation.
1860
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001861- The pyexpat module supports a number of new handlers, which are
1862 available only in expat 1.2. If invocation of a callback fails, it
1863 will report an additional frame in the traceback. Parser objects
1864 participate now in garbage collection. If expat reports an unknown
1865 encoding, pyexpat will try to use a Python codec; that works only
1866 for single-byte charsets. The parser type objects is exposed as
1867 XMLParserObject.
1868
1869- xml.dom now offers standard definitions for symbolic node type and
1870 exception code constants, and a hierarchy of DOM exceptions. minidom
1871 was adjusted to use them.
1872
1873- The conformance of xml.dom.minidom to the DOM specification was
1874 improved. It detects a number of additional error cases; the
1875 previous/next relationship works even when the tree is modified;
1876 Node supports the normalize() method; NamedNodeMap, DocumentType and
1877 DOMImplementation classes were added; Element supports the
1878 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1879 method.
1880
Guido van Rossumf61f1662001-01-10 20:13:55 +00001881Build issues
1882
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001883- For Unix (and Unix-compatible) builds, configuration and building of
1884 extension modules is now greatly automated. Rather than having to
1885 edit the Modules/Setup file to indicate which modules should be
1886 built and where their include files and libraries are, a
1887 distutils-based setup.py script now takes care of building most
1888 extension modules. All extension modules built this way are built
1889 as shared libraries. Only a few modules that must be linked
1890 statically are still listed in the Setup file; you won't need to
1891 edit their configuration.
1892
1893- Python should now build out of the box on Cygwin. If it doesn't,
1894 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001895
1896- Python now always uses its own (renamed) implementation of getopt()
1897 -- there's too much variation among C library getopt()
1898 implementations.
1899
1900- C++ compilers are better supported; the CXX macro is always set to a
1901 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001902
Tim Petersd92dfe02000-12-12 01:18:41 +00001903Windows changes
1904
1905- select module: By default under Windows, a select() call
1906 can specify no more than 64 sockets. Python now boosts
1907 this Microsoft default to 512. If you need even more than
1908 that, see the MS docs (you'll need to #define FD_SETSIZE
1909 and recompile Python from source).
1910
Guido van Rossumf61f1662001-01-10 20:13:55 +00001911- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1912 subdirectory is no more!
1913
Tim Petersa3a3a032000-11-30 05:22:44 +00001914
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001915What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001916=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001917
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001918Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001919changes are in the file HISTORY. If you are making the jump directly
1920from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1921HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001922
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001923Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1924the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1925http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001926
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001927--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001928
1929======================================================================
1930
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001931What's new in 2.0 (since release candidate 1)?
1932==============================================
1933
1934Standard library
1935
1936- The copy_reg module was modified to clarify its intended use: to
1937 register pickle support for extension types, not for classes.
1938 pickle() will raise a TypeError if it is passed a class.
1939
1940- Fixed a bug in gettext's "normalize and expand" code that prevented
1941 it from finding an existing .mo file.
1942
1943- Restored support for HTTP/0.9 servers in httplib.
1944
Tim Peters989b7b92000-10-16 20:24:53 +00001945- The math module was changed to stop raising OverflowError in case of
1946 underflow, and return 0 instead in underflow cases. Whether Python
1947 used to raise OverflowError in case of underflow was platform-
1948 dependent (it did when the platform math library set errno to ERANGE
1949 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001950
1951- Fixed a bug in StringIO that occurred when the file position was not
1952 at the end of the file and write() was called with enough data to
1953 extend past the end of the file.
1954
1955- Fixed a bug that caused Tkinter error messages to get lost on
1956 Windows. The bug was fixed by replacing direct use of
1957 interp->result with Tcl_GetStringResult(interp).
1958
1959- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1960 redirect response.
1961
1962- Several changes were made to distutils: Some debugging code was
1963 removed from util. Fixed the installer used when an external zip
1964 program (like WinZip) is not found; the source code for this
1965 installer is in Misc/distutils. check_lib() was modified to behave
1966 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1967 test for whether installed modules are on sys.path was changed to
1968 use both normcase() and normpath().
1969
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001970- Several minor bugs were fixed in the xml package (the minidom,
1971 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001972
1973- The regression test driver (regrtest.py) behavior when invoked with
1974 -l changed: It now reports a count of objects that are recognized as
1975 garbage but not freed by the garbage collector.
1976
Tim Peters989b7b92000-10-16 20:24:53 +00001977- The regression test for the math module was changed to test
1978 exceptional behavior when the test is run in verbose mode. Python
1979 cannot yet guarantee consistent exception behavior across platforms,
1980 so the exception part of test_math is run only in verbose mode, and
1981 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001982
1983Internals
1984
1985- PyOS_CheckStack() has been disabled on Win64, where it caused
1986 test_sre to fail.
1987
1988Build issues
1989
1990- Changed compiler flags, so that gcc is always invoked with -Wall and
1991 -Wstrict-prototypes. Users compiling Python with GCC should see
1992 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001993 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001994 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001995
Tim Petersa3a3a032000-11-30 05:22:44 +00001996- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001997
1998Tools and other miscellany
1999
2000- The compiler in Tools/compiler was updated to support the new
2001 language features introduced in 2.0: extended print statement, list
2002 comprehensions, and augmented assignments. The new compiler should
2003 also be backwards compatible with Python 1.5.2; the compiler will
2004 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002005 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002006
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002007What's new in 2.0 release candidate 1 (since beta 2)?
2008=====================================================
2009
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002010What is release candidate 1?
2011
2012We believe that release candidate 1 will fix all known bugs that we
2013intend to fix for the 2.0 final release. This release should be a bit
2014more stable than the previous betas. We would like to see even more
2015widespread testing before the final release, so we are producing this
2016release candidate. The final release will be exactly the same unless
2017any show-stopping (or brown bag) bugs are found by testers of the
2018release candidate.
2019
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002020All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002021to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002022
2023Core language, builtins, and interpreter
2024
2025- A bug that caused crashes when __coerce__ was used with augmented
2026 assignment, e.g. +=, was fixed.
2027
2028- Raise ZeroDivisionError when raising zero to a negative number,
2029 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2030 power operator and the result of math.pow(0.0, -2.0) will vary by
2031 platform. On Linux, it raises a ValueError.
2032
2033- A bug in Unicode string interpolation was fixed that occasionally
2034 caused errors with formats including "%%". For example, the
2035 following expression "%% %s" % u"abc" no longer raises a TypeError.
2036
2037- Compilation of deeply nested expressions raises MemoryError instead
2038 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2039
2040- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2041 rendering them useless. They are now written in binary mode again.
2042
2043Standard library
2044
2045- Keyword arguments are now accepted for most pattern and match object
2046 methods in SRE, the standard regular expression engine.
2047
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002048- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002049 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002050
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002051- Several bugs in the Unicode handling and error handling in _tkinter
2052 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002053
2054- Fix memory management errors in Merge() and Tkapp_Call() routines.
2055
2056- Several changes were made to cStringIO to make it compatible with
2057 the file-like object interface and with StringIO. If operations are
2058 performed on a closed object, an exception is raised. The truncate
2059 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002060 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002061
2062- There were many changes made to the linuxaudiodev module and its
2063 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002064 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002065
2066 Note that this module is named poorly, because it should work
2067 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002068 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002069
2070 The module now raises exceptions when errors occur instead of
2071 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2072 audio) and defines a getptr() method that calls the
2073 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2074
2075- The library_version attribute, introduced in an earlier beta, was
2076 removed because it can not be supported with early versions of the C
2077 readline library, which provides no way to determine the version at
2078 compile-time.
2079
2080- The binascii module is now enabled on Win64.
2081
Tim Peters46446d62000-10-09 21:19:31 +00002082- tokenize.py no longer suffers "recursion depth" errors when parsing
2083 programs with very long string literals.
2084
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002085Internals
2086
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002087- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002088 which is called when the interpreter starts up to determine where
2089 the standard library is installed. These vulnerabilities affect all
2090 previous versions of Python and can be exploited by setting very
2091 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2092 setuid Python script, although use of the wrapper in
2093 Misc/setuid-prog.c will eliminate the vulnerability.
2094
2095- Fixed garbage collection bugs in instance creation that were
2096 triggered when errors occurred during initialization. The solution,
2097 applied in cPickle and in PyInstance_New(), is to call
2098 PyObject_GC_Init() after the initialization of the object's
2099 container attributes is complete.
2100
2101- pyexpat adds definitions of PyModule_AddStringConstant and
2102 PyModule_AddObject if the Python version is less than 2.0, which
2103 provides compatibility with PyXML on Python 1.5.2.
2104
2105- If the platform has a bogus definition for LONG_BIT (the number of
2106 bits in a long), an error will be reported at compile time.
2107
2108- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2109 collection crashes and possibly other, unreported crashes.
2110
2111- Fixed a memory leak in _PyUnicode_Fini().
2112
2113Build issues
2114
2115- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002116 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002117 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002118
2119- The mmap.PAGESIZE constant is now initialized using sysconf when
2120 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2121
2122- The md5 file should now compile on all platforms.
2123
2124- The select module now compiles on platforms that do not define
2125 POLLRDNORM and related constants.
2126
2127- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002128 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002129
Jeremy Hylton10921202000-10-09 18:34:12 +00002130- BeOS: A number of changes were made to the build and installation
2131 process. ar-fake now operates on a directory of object files.
2132 dl_export.h is gone, and its macros now appear on the mwcc command
2133 line during build on PPC BeOS.
2134
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002135- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002136 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002137
2138- Cygwin: Support for shared libraries, Tkinter, and sockets.
2139
2140- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2141
2142Tools and other miscellany
2143
2144- Removed debugging prints from main used with freeze.
2145
Tim Peters46446d62000-10-09 21:19:31 +00002146- IDLE auto-indent no longer crashes when it encounters Unicode
2147 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002148
2149What's new in 2.0 beta 2 (since beta 1)?
2150========================================
2151
2152Core language, builtins, and interpreter
2153
Tim Peters482c0212000-09-26 06:33:09 +00002154- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002155 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002156
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002157- Add -h and -V command line options to print the usage message and
2158 Python version number and exit immediately.
2159
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002160- eval() and exec accept Unicode objects as code parameters.
2161
2162- getattr() and setattr() now also accept Unicode objects for the
2163 attribute name, which are converted to strings using the default
2164 encoding before lookup.
2165
2166- Multiplication on string and Unicode now does proper bounds
2167 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2168 string is too long."
2169
2170- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002171 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002172
Jeremy Hylton1b618592000-09-26 05:32:36 +00002173
2174Standard library and extensions
2175
Guido van Rossum5b08f132001-04-16 02:05:23 +00002176- socket module: the OpenSSL code now adds support for RAND_status()
2177 and EGD (Entropy Gathering Device).
2178
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002179- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002180 argument checking; it still takes no arguments.
2181
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002182- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002183
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002184- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002185
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002186- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002187
2188- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002189 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002190
2191- copy: Copy Unicode objects atomically.
2192
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002193- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002194
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002195- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002196
Fred Drake67233bc2000-09-26 16:40:27 +00002197- dbm: Add get() and setdefault() methods to dbm object. Add constant
2198 `library' to module that names the library used. Added doc strings
2199 and method names to error messages. Uses configure to determine
2200 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2201 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002202
2203- distutils: Update to version 0.9.3.
2204
2205- dl: Add several dl.RTLD_ constants.
2206
2207- fpectl: Now supported on FreeBSD.
2208
2209- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2210 found by the collector will be saved in gc.garbage. This is useful
2211 for debugging a program that creates reference cycles.
2212
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002213- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002214 of HTTP class. Do not close socket on zero-length response. Do not
2215 crash when server sends invalid content-length header.
2216
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002217- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002218
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002219- marshal: When reading a short, sign-extend on platforms where shorts
2220 are bigger than 16 bits. When reading a long, repair the unportable
2221 sign extension that was being done for 64-bit machines. (It assumed
2222 that signed right shift sign-extends.)
2223
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002224- operator: Add contains(), invert(), __invert__() as aliases for
2225 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002226
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002227- os: Add support for popen2() and popen3() on all platforms where
2228 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002229
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002230- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002231 clicking on a file in Explorer (or passing the file name to the
2232 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002233
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002234- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002235 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002236
2237- pickle: Now raises ValueError when an invalid pickle that contains
2238 a non-string repr where a string repr was expected. This behavior
2239 matches cPickle.
2240
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002241- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002242
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002243- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002244
2245- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002246 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002247 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002248
2249- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002250 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002251
2252- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002253 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002254 few cycles during startup since the first call to
2255 setdefaultencoding() will initialize the codec registry and the
2256 encodings package.
2257
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002258- socket: Support for size hint in readlines() method of object returned
2259 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002260
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002261- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002262 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002263 is followed by whitespace.
2264
Tim Petersa3a3a032000-11-30 05:22:44 +00002265- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002266
2267- struct: Check ranges for bytes and shorts.
2268
2269- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002270 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002271
2272- Tkinter: Image objects are now guaranteed to have unique ids. Set
2273 event.delta to zero if Tk version doesn't support mousewheel.
2274 Removed some debugging prints.
2275
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002276- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002277
Fred Drake67233bc2000-09-26 16:40:27 +00002278- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002279 which works around a bug in Norton AntiVirus 2000 that leads directly
2280 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002281
2282- xml: New version detection code allows PyXML to override standard
2283 XML package if PyXML version is greater than 0.6.1.
2284
Fred Drake64bb3802000-09-26 16:21:35 +00002285- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2286 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2287 tree only for nodes which are sufficiently interesting to a specific
2288 application. Does not provide the HTML-specific extensions. Still
2289 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002290
Fred Drake64bb3802000-09-26 16:21:35 +00002291- xml.sax: SAX 2 support for Python, including all the handler
2292 interfaces needed to process XML 1.0 compliant XML. Some
2293 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002294
Fred Drake64bb3802000-09-26 16:21:35 +00002295- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2296 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002297
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002298
Jeremy Hylton1b618592000-09-26 05:32:36 +00002299C API
2300
2301- Add three new convenience functions for module initialization --
2302 PyModule_AddObject(), PyModule_AddIntConstant(), and
2303 PyModule_AddStringConstant().
2304
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002305- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002306 removed and add #error to Python.h if NULL isn't defined after
2307 #include of stdio.h.
2308
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002309- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002310 backwards compatibility (at the source level) with old extensions.
2311
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002312- A wrapper API was added for signal() and sigaction(). Instead of
2313 either function, always use PyOS_getsig() to get a signal handler
2314 and PyOS_setsig() to set one. A new convenience typedef
2315 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002316
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002317- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002318 internal data buffer and size of a string object -- or the default
2319 encoded version of a Unicode object.
2320
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002321- PyString_Size() and PyString_AsString() accept Unicode objects.
2322
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002323- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002324 exists). INT_MAX and LONG_MAX will always be defined, even if
2325 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002326
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002327- PyFloat_FromString takes a second argument, pend, that was
2328 effectively useless. It is now officially useless but preserved for
2329 backwards compatibility. If the pend argument is not NULL, *pend is
2330 set to NULL.
2331
2332- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2333 for the attribute name. See note on getattr() above.
2334
2335- A few bug fixes to argument processing for Unicode.
2336 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2337 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2338 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002339 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002340
2341- Py_BuildValue accepts B format (for bgen-generated code).
2342
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002343
Jeremy Hylton1b618592000-09-26 05:32:36 +00002344Internals
2345
2346- On Unix, fix code for finding Python installation directory so that
2347 it works when argv[0] is a relative path.
2348
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002349- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002350 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002351 rather than by generating a copy of the object.
2352
Tim Peters482c0212000-09-26 06:33:09 +00002353- Several of the internal Unicode tables are much smaller now, and
2354 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002355
Jeremy Hylton97693b02000-09-26 17:42:51 +00002356- In the garbage collector: Fixed bug in collection of tuples. Fixed
2357 bug that caused some instances to be removed from the container set
2358 while they were still live. Fixed parsing in gc.set_debug() for
2359 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002360
2361- Fixed refcount problem in instance deallocation that only occurred
2362 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2363
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002364- On Windows, getpythonregpath is now protected against null data in
2365 registry key.
2366
2367- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002368 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002369
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002370
Jeremy Hylton1b618592000-09-26 05:32:36 +00002371Build and platform-specific issues
2372
2373- Better support of GNU Pth via --with-pth configure option.
2374
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002375- Python/C API now properly exposed to dynamically-loaded extension
2376 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002377
2378- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2379 Don't define MS_SYNC to be zero when it is undefined. Added missing
2380 prototypes in posixmodule.c.
2381
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002382- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002383 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002384
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002385- Fix largefile support on older NetBSD systems and OpenBSD by adding
2386 define for TELL64.
2387
2388
2389Tools and other miscellany
2390
2391- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2392
2393- freeze: The modulefinder now works with 2.0 opcodes.
2394
Tim Petersa3a3a032000-11-30 05:22:44 +00002395- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002396 Move hackery of sys.argv until after the Tk instance has been
2397 created, which allows the application-specific Tkinter
2398 initialization to be executed if present; also pass an explicit
2399 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002400
Jeremy Hylton1b618592000-09-26 05:32:36 +00002401
2402What's new in 2.0 beta 1?
2403=========================
2404
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002405Source Incompatibilities
2406------------------------
2407
2408None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2409such as single-argument append(), connect() and bind(), and changes to
2410str(long) and repr(float).
2411
2412
2413Binary Incompatibilities
2414------------------------
2415
2416- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2417with Python 2.0; these extensions will have to be rebuilt for Python
24182.0.
2419
2420- On Windows, attempting to import a third party extension built for
2421Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2422can do about this. Check your PYTHONPATH environment variable!
2423
2424- Python bytecode files (*.pyc and *.pyo) are not compatible between
2425releases.
2426
2427
2428Overview of Changes Since 1.6
2429-----------------------------
2430
2431There are many new modules (including brand new XML support through
2432the xml package, and i18n support through the gettext module); a list
2433of all new modules is included below. Lots of bugs have been fixed.
2434
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002435The process for making major new changes to the language has changed
2436since Python 1.6. Enhancements must now be documented by a Python
2437Enhancement Proposal (PEP) before they can be accepted.
2438
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002439There are several important syntax enhancements, described in more
2440detail below:
2441
2442 - Augmented assignment, e.g. x += 1
2443
2444 - List comprehensions, e.g. [x**2 for x in range(10)]
2445
2446 - Extended import statement, e.g. import Module as Name
2447
2448 - Extended print statement, e.g. print >> file, "Hello"
2449
2450Other important changes:
2451
2452 - Optional collection of cyclical garbage
2453
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002454Python Enhancement Proposal (PEP)
2455---------------------------------
2456
2457PEP stands for Python Enhancement Proposal. A PEP is a design
2458document providing information to the Python community, or describing
2459a new feature for Python. The PEP should provide a concise technical
2460specification of the feature and a rationale for the feature.
2461
2462We intend PEPs to be the primary mechanisms for proposing new
2463features, for collecting community input on an issue, and for
2464documenting the design decisions that have gone into Python. The PEP
2465author is responsible for building consensus within the community and
2466documenting dissenting opinions.
2467
2468The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002469
2470Augmented Assignment
2471--------------------
2472
2473This must have been the most-requested feature of the past years!
2474Eleven new assignment operators were added:
2475
Guido van Rossume905e952000-09-05 12:42:46 +00002476 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002477
2478For example,
2479
2480 A += B
2481
2482is similar to
2483
2484 A = A + B
2485
2486except that A is evaluated only once (relevant when A is something
2487like dict[index].attr).
2488
2489However, if A is a mutable object, A may be modified in place. Thus,
2490if A is a number or a string, A += B has the same effect as A = A+B
2491(except A is only evaluated once); but if a is a list, A += B has the
2492same effect as A.extend(B)!
2493
2494Classes and built-in object types can override the new operators in
2495order to implement the in-place behavior; the not-in-place behavior is
2496used automatically as a fallback when an object doesn't implement the
2497in-place behavior. For classes, the method name is derived from the
2498method name for the corresponding not-in-place operator by inserting
2499an 'i' in front of the name, e.g. __iadd__ implements in-place
2500__add__.
2501
2502Augmented assignment was implemented by Thomas Wouters.
2503
2504
2505List Comprehensions
2506-------------------
2507
2508This is a flexible new notation for lists whose elements are computed
2509from another list (or lists). The simplest form is:
2510
2511 [<expression> for <variable> in <sequence>]
2512
Guido van Rossum56db0952000-09-06 23:34:25 +00002513For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002514This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002515
2516You can also add a condition:
2517
2518 [<expression> for <variable> in <sequence> if <condition>]
2519
2520For example, [w for w in words if w == w.lower()] would yield the list
2521of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002522than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002523
2524You can also have nested for loops and more than one 'if' clause. For
2525example, here's a function that flattens a sequence of sequences::
2526
2527 def flatten(seq):
2528 return [x for subseq in seq for x in subseq]
2529
2530 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2531
2532This prints
2533
2534 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2535
2536List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002537Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002538
2539
2540Extended Import Statement
2541-------------------------
2542
2543Many people have asked for a way to import a module under a different
2544name. This can be accomplished like this:
2545
2546 import foo
2547 bar = foo
2548 del foo
2549
2550but this common idiom gets old quickly. A simple extension of the
2551import statement now allows this to be written as follows:
2552
2553 import foo as bar
2554
2555There's also a variant for 'from ... import':
2556
2557 from foo import bar as spam
2558
2559This also works with packages; e.g. you can write this:
2560
2561 import test.regrtest as regrtest
2562
2563Note that 'as' is not a new keyword -- it is recognized only in this
2564context (this is only possible because the syntax for the import
2565statement doesn't involve expressions).
2566
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002567Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002568
2569
2570Extended Print Statement
2571------------------------
2572
2573Easily the most controversial new feature, this extension to the print
2574statement adds an option to make the output go to a different file
2575than the default sys.stdout.
2576
2577For example, to write an error message to sys.stderr, you can now
2578write:
2579
2580 print >> sys.stderr, "Error: bad dog!"
2581
2582As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002583evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002584
2585 print >> None, "Hello world"
2586
2587is equivalent to
2588
2589 print "Hello world"
2590
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002591Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002592
2593
2594Optional Collection of Cyclical Garbage
2595---------------------------------------
2596
2597Python is now equipped with a garbage collector that can hunt down
2598cyclical references between Python objects. It's no replacement for
2599reference counting; in fact, it depends on the reference counts being
2600correct, and decides that a set of objects belong to a cycle if all
2601their reference counts can be accounted for from their references to
2602each other. This devious scheme was first proposed by Eric Tiedemann,
2603and brought to implementation by Neil Schemenauer.
2604
2605There's a module "gc" that lets you control some parameters of the
2606garbage collection. There's also an option to the configure script
2607that lets you enable or disable the garbage collection. In 2.0b1,
2608it's on by default, so that we (hopefully) can collect decent user
2609experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002610performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002611off by default in the final 2.0 release.
2612
2613
2614Smaller Changes
2615---------------
2616
2617A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2618map(None, seq1, seq2, ...) when the sequences have the same length;
2619i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2620the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002621zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002622
2623sys.version_info is a tuple (major, minor, micro, level, serial).
2624
2625Dictionaries have an odd new method, setdefault(key, default).
2626dict.setdefault(key, default) returns dict[key] if it exists; if not,
2627it sets dict[key] to default and returns that value. Thus:
2628
2629 dict.setdefault(key, []).append(item)
2630
2631does the same work as this common idiom:
2632
2633 if not dict.has_key(key):
2634 dict[key] = []
2635 dict[key].append(item)
2636
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002637There are two new variants of SyntaxError that are raised for
2638indentation-related errors: IndentationError and TabError.
2639
2640Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2641escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002642
2643The limits on the size of expressions and file in Python source code
2644have been raised from 2**16 to 2**32. Previous versions of Python
2645were limited because the maximum argument size the Python VM accepted
2646was 2**16. This limited the size of object constructor expressions,
2647e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2648limit was raised thanks to a patch by Charles Waldman that effectively
2649fixes the problem. It is now much more likely that you will be
2650limited by available memory than by an arbitrary limit in Python.
2651
2652The interpreter's maximum recursion depth can be modified by Python
2653programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2654limit is the maximum number of recursive calls that can be made by
2655Python code. The limit exists to prevent infinite recursion from
2656overflowing the C stack and causing a core dump. The default value is
26571000. The maximum safe value for a particular platform can be found
2658by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002659
2660New Modules and Packages
2661------------------------
2662
2663atexit - for registering functions to be called when Python exits.
2664
2665imputil - Greg Stein's alternative API for writing custom import
2666hooks.
2667
2668pyexpat - an interface to the Expat XML parser, contributed by Paul
2669Prescod.
2670
2671xml - a new package with XML support code organized (so far) in three
2672subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2673would fill a volume. There's a special feature whereby a
2674user-installed package named _xmlplus overrides the standard
2675xmlpackage; this is intended to give the XML SIG a hook to distribute
2676backwards-compatible updates to the standard xml package.
2677
2678webbrowser - a platform-independent API to launch a web browser.
2679
2680
Guido van Rossume905e952000-09-05 12:42:46 +00002681Changed Modules
2682---------------
2683
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002684array -- new methods for array objects: count, extend, index, pop, and
2685remove
2686
2687binascii -- new functions b2a_hex and a2b_hex that convert between
2688binary data and its hex representation
2689
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002690calendar -- Many new functions that support features including control
2691over which day of the week is the first day, returning strings instead
2692of printing them. Also new symbolic constants for days of week,
2693e.g. MONDAY, ..., SUNDAY.
2694
2695cgi -- FieldStorage objects have a getvalue method that works like a
2696dictionary's get method and returns the value attribute of the object.
2697
2698ConfigParser -- The parser object has new methods has_option,
2699remove_section, remove_option, set, and write. They allow the module
2700to be used for writing config files as well as reading them.
2701
2702ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002703optionally support the RFC 959 REST command.
2704
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002705gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002706
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002707httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2708the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002709
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002710locale -- implement getdefaultlocale for Win32 and Macintosh
2711
2712marshal -- no longer dumps core when marshaling deeply nested or
2713recursive data structures
2714
2715os -- new functions isatty, seteuid, setegid, setreuid, setregid
2716
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002717os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2718support under Unix.
2719
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002720os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002721
2722os.path -- fix semantics of os.path.commonprefix
2723
2724smtplib -- support for sending very long messages
2725
2726socket -- new function getfqdn()
2727
2728readline -- new functions to read, write and truncate history files.
2729The readline section of the library reference manual contains an
2730example.
2731
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002732select -- add interface to poll system call
2733
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002734shutil -- new copyfileobj function
2735
2736SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2737HTTP server.
2738
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002739Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002740
2741urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002742e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002743
2744whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002745
2746
2747Obsolete Modules
2748----------------
2749
2750None. However note that 1.6 made a whole slew of modules obsolete:
2751stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2752poly, zmod, strop, util, whatsound.
2753
2754
2755Changed, New, Obsolete Tools
2756----------------------------
2757
Tim Peters8b092332000-09-05 20:15:25 +00002758None.
Guido van Rossume905e952000-09-05 12:42:46 +00002759
2760
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002761C-level Changes
2762---------------
2763
2764Several cleanup jobs were carried out throughout the source code.
2765
2766All C code was converted to ANSI C; we got rid of all uses of the
2767Py_PROTO() macro, which makes the header files a lot more readable.
2768
2769Most of the portability hacks were moved to a new header file,
2770pyport.h; several other new header files were added and some old
2771header files were removed, in an attempt to create a more rational set
2772of header files. (Few of these ever need to be included explicitly;
2773they are all included by Python.h.)
2774
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002775Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002776and Win64, especially for the new Intel Itanium processor. Mick also
2777added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002778
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002779The C APIs to return an object's size have been update to consistently
2780use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2781previous versions, the abstract interfaces used PyXXX_Length and the
2782concrete interfaces used PyXXX_Size. The old names,
2783e.g. PyObject_Length, are still available for backwards compatibility
2784at the API level, but are deprecated.
2785
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002786The PyOS_CheckStack function has been implemented on Windows by
2787Fredrik Lundh. It prevents Python from failing with a stack overflow
2788on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002789
2790The GC changes resulted in creation of two new slots on object,
2791tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002792the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002793
2794The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002795C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002796
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002797PyErr_Format has been updated to automatically calculate the size of
2798the buffer needed to hold the formatted result string. This change
2799prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002800
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002801New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002802
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002803PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2804that are the same as their non-Ex counterparts except they take an
2805extra flag argument that tells them to close the file when done.
2806
2807XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002808
Tim Peters8b092332000-09-05 20:15:25 +00002809
2810Windows Changes
2811---------------
2812
2813New popen2/popen3/peopen4 in os module (see Changed Modules above).
2814
2815os.popen is much more usable on Windows 95 and 98. See Microsoft
2816Knowledge Base article Q150956. The Win9x workaround described there
2817is implemented by the new w9xpopen.exe helper in the root of your
2818Python installation. Note that Python uses this internally; it is not
2819a standalone program.
2820
2821Administrator privileges are no longer required to install Python
2822on Windows NT or Windows 2000. If you have administrator privileges,
2823Python's registry info will be written under HKEY_LOCAL_MACHINE.
2824Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002825under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002826uses of Python, but will prevent some advanced uses from working
2827(for example, running a Python script as an NT service, or possibly
2828from CGI).
2829
2830[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2831installer; instead, it installs the needed Tcl/Tk files directly in the
2832Python directory. If you already have a Tcl/Tk installation, this
2833wastes some disk space (about 4 Megs) but avoids problems with
2834conflicting Tcl/Tk installations, and makes it much easier for Python
2835to ensure that Tcl/Tk can find all its files.
2836
2837[This was new in 1.6] The Windows installer now installs by default in
2838\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2839
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002840
2841Updates to the changes between 1.5.2 and 1.6
2842--------------------------------------------
2843
2844The 1.6 NEWS file can't be changed after the release is done, so here
2845is some late-breaking news:
2846
2847New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2848and changes to getlocale() and setlocale().
2849
2850The new module is now enabled per default.
2851
2852It is not true that the encodings codecs cannot be used for normal
2853strings: the string.encode() (which is also present on 8-bit strings
2854!) allows using them for 8-bit strings too, e.g. to convert files from
2855cp1252 (Windows) to latin-1 or vice-versa.
2856
2857Japanese codecs are available from Tamito KAJIYAMA:
2858http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2859
2860
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002861======================================================================