blob: 13f3fb57ade5ff6ed5871a0a9cb073b8573abee7 [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
Guido van Rossumc8e56452001-10-22 00:43:43 +00007- Methods of built-in types now properly check for keyword arguments
8 (formerly these were silently ignored). The only built-in methods
9 that take keyword arguments are __call__, __init__ and __new__.
10
Tim Peters84362bc2001-10-19 17:55:30 +000011Core and builtins
12
13Extension modules
14
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000015- Various bugfixes to the curses module.
16
Tim Peters84362bc2001-10-19 17:55:30 +000017Library
18
19Tools/Demos
20
21Build
22
23C API
24
25New platforms
26
27Tests
28
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000029- Added a test script for the curses module. It isn't run automatically;
30 regrtest.py must be run with '-u curses' to enable it.
31
Tim Peters84362bc2001-10-19 17:55:30 +000032Windows
33
34
Tim Petersabf925f2001-09-28 21:53:42 +000035What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +000036Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +000037===========================
38
39Type/class unification and new-style classes
40
Guido van Rossum687ae002001-10-15 22:03:32 +000041- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +000042 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +000043 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000044 remains: the __dict__ of a new-style class is a read-only proxy; you
45 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000046 __defined__ attribute of new-style types no longer exists, for lack
47 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000048 future a __cache__ may be resurrected with a similar function, if I
49 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000050
Tim Peters1c9ca872001-10-04 06:43:12 +000051- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
52 always returned None, even when there was a class docstring).
53
54- doctest now finds and runs docstrings attached to new-style classes,
55 class methods, static methods, and properties.
56
Guido van Rossum9074ef62001-10-16 21:34:49 +000057Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +000058
Guido van Rossuma8bcf802001-10-15 15:53:58 +000059- A very subtle syntactical pitfall in list comprehensions was fixed.
60 For example: [a+b for a in 'abc', for b in 'def']. The comma in
61 this example is a mistake. Previously, this would silently let 'a'
62 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
63 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
64 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
65 Note that [a for a in <singleton>] is a convoluted way to say
66 [<singleton>] anyway, so it's not like any expressiveness is lost.
67
Guido van Rossum9074ef62001-10-16 21:34:49 +000068- getattr(obj, name, default) now only catches AttributeError, as
69 documented, rather than returning the default value for all
70 exceptions (which could mask bugs in a __getattr__ hook, for
71 example).
72
Fred Drakecb7a6b52001-10-22 18:41:51 +000073- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +000074 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +000075 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +000076 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +000077
Guido van Rossum1c486092001-10-19 02:05:35 +000078- unicode(obj) now behaves more like str(obj), accepting arbitrary
79 objects, and calling a __unicode__ method if it exists.
80 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +000081 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +000082
Barry Warsawf6fb1712001-10-19 05:35:40 +000083- isinstance() now allows any object as the first argument and a
84 class, a type or something with a __bases__ tuple attribute for the
85 second argument. The second argument may also be a tuple of a
86 class, type, or something with __bases__, in which case isinstance()
87 will return true if the first argument is an instance of any of the
88 things contained in the second argument tuple. E.g.
89
90 isinstance(x, (A, B))
91
92 returns true if x is an instance of A or B.
93
Guido van Rossum9074ef62001-10-16 21:34:49 +000094Extension modules
95
96- thread.start_new_thread() now returns the thread ID (previously None).
97
Martin v. Löwis16dc7f42001-09-30 20:32:11 +000098- binascii has now two quopri support functions, a2b_qp and b2a_qp.
99
Guido van Rossumc524d952001-10-19 01:31:59 +0000100- readline now supports setting the startup_hook and the
101 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000102
Guido van Rossumc524d952001-10-19 01:31:59 +0000103- os and posix supports chroot(), setgroups() and unsetenv() where
104 available. The stat(), fstat(), statvfs() and fstatvfs() functions
105 now return "pseudo-sequences" -- the various fields can now be
106 accessed as attributes (e.g. os.stat("/").st_mtime) but for
107 backwards compatibility they also behave as a fixed-length sequence.
108 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000109 attributes.
110
111- time: localtime(), gmtime() and strptime() now return a
112 pseudo-sequence similar to the os.stat() return value, with
113 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000114
Guido van Rossum9074ef62001-10-16 21:34:49 +0000115- Decompression objects in the zlib module now accept an optional
116 second parameter to decompress() that specifies the maximum amount
117 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000118
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000119- optional SSL support in the socket module now exports OpenSSL
120 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
121 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000122 automatically seed its PRNG. Also, the keyfile and certfile
123 arguments to socket.ssl() are now optional.
124
125- posixmodule (and by extension, the os module on POSIX platforms) now
126 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000127
Guido van Rossum9074ef62001-10-16 21:34:49 +0000128Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000129
Tim Peters7402f792001-10-02 03:53:41 +0000130- doctest now excludes functions and classes not defined by the module
131 being tested, thanks to Tim Hochberg.
132
Fred Drakecb7a6b52001-10-22 18:41:51 +0000133- HotShot, a new profiler implemented using a C-based callback, has
134 been added. This substantially reduces the overhead of profiling,
135 but it is still quite preliminary. Support modules and
136 documentation will be added in upcoming releases (before 2.2 final).
137
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000138- profile now produces correct output in situations where an exception
139 raised in Python is cleared by C code (e.g. hasattr()). This used
140 to cause wrong output, including spurious claims of recursive
141 functions and attribution of time spent to the wrong function.
142
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000143 The code and documentation for the derived OldProfile and HotProfile
144 profiling classes was removed. The code hasn't worked for years (if
145 you tried to use them, they raised exceptions). OldProfile
146 intended to reproduce the behavior of the profiler Python used more
147 than 7 years ago, and isn't interesting anymore. HotProfile intended
148 to provide a faster profiler (but producing less information), and
149 that's a worthy goal we intend to meet via a different approach (but
150 without losing information).
151
Tim Peterscce092d2001-10-09 05:31:56 +0000152- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000153 a much better system-specific calibration constant. The constant can
154 now be specified in an instance constructor, or as a Profile class or
155 instance variable, instead of by editing profile.py's source code.
156 Calibration must still be done manually (see the docs for the profile
157 module).
158
159 Note that Profile.calibrate() must be overriden by subclasses.
160 Improving the accuracy required exploiting detailed knowledge of
161 profiler internals; the earlier method abstracted away the details
162 and measured a simplified model instead, but consequently computed
163 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000164
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000165- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000166 which indicates whether output is intended for the header 'Q'
167 encoding.
168
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000169- The SocketServer.ThreadingMixIn class now closes the request after
170 finish_request() returns. (Not when it errors out though.)
171
Barry Warsawf6fb1712001-10-19 05:35:40 +0000172- The nntplib module's NNTP.body() method has grown a `file' argument
173 to allow saving the message body to a file.
174
175- The email package has added a class email.Parser.HeaderParser which
176 only parses headers and does not recurse into the message's body.
177 Also, the module/class MIMEAudio has been added for representing
178 audio data (contributed by Anthony Baxter).
179
180- ftplib should be able to handle files > 2GB.
181
182- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
183 ON, and OFF.
184
Fred Drakecb7a6b52001-10-22 18:41:51 +0000185- xml.dom.minidom NodeList objects now support the length attribute
186 and item() method as required by the DOM specifications.
187
Guido van Rossumed554f62001-10-02 23:15:37 +0000188Tools/Demos
189
190- Demo/dns was removed. It no longer serves any purpose; a package
191 derived from it is now maintained by Anthony Baxter, see
192 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000193
Barry Warsawf6fb1712001-10-19 05:35:40 +0000194- The freeze tool has been made more robust, and two new options have
195 been added: -X and -E.
196
Tim Petersabf925f2001-09-28 21:53:42 +0000197Build
198
Barry Warsawf6fb1712001-10-19 05:35:40 +0000199- configure will use CXX in LINKCC if CXX is used to build main() and
200 the system requires to link a C++ main using the C++ compiler.
201
Tim Petersabf925f2001-09-28 21:53:42 +0000202C API
203
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000204- The documentation for the tp_compare slot is updated to require that
205 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
206 not correct. This is not yet enforced but will be enforced in
207 Python 2.3; even later, we may use -2 to indicate errors and +2 for
208 "NotImplemented". Right now, -1 should be used for an error return.
209
Tim Petersd38b1c72001-09-30 05:09:37 +0000210- PyLong_AsLongLong() now accepts int (as well as long) arguments.
211 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
212 as long) arguments.
213
Guido van Rossum3c288632001-10-16 21:13:49 +0000214- PyThread_start_new_thread() now returns a long int giving the thread
215 ID, if one can be calculated; it returns -1 for error, 0 if no
216 thread ID is calculated (this is an incompatible change, but only
217 the thread module used this API). This code has only really been
218 tested on Linux and Windows; other platforms please beware (and
219 report any bugs or strange behavior).
220
Guido van Rossum1c486092001-10-19 02:05:35 +0000221- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
222 input.
223
Tim Petersabf925f2001-09-28 21:53:42 +0000224New platforms
225
226Tests
227
228Windows
229
Tim Peters04cf1d32001-10-09 22:39:40 +0000230- Installer: If you install IDLE, and don't disable file-extension
231 registration, a new "Edit with IDLE" context (right-click) menu entry
232 is created for .py and .pyw files.
233
Tim Peters1ce3cf72001-10-01 17:58:40 +0000234- The signal module now supports SIGBREAK on Windows, thanks to Steven
235 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
236 action remains to call Win32 ExitProcess(). This can be changed via
237 signal.signal(). For example:
238
239 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
240 # (SIGINT) behavior.
241 import signal
242 signal.signal(signal.SIGBREAK,
243 signal.default_int_handler)
244
245 try:
246 while 1:
247 pass
248 except KeyboardInterrupt:
249 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
250 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
251 # program without the possibility for any Python-level cleanup).
252 print "Clean exit"
253
Tim Petersabf925f2001-09-28 21:53:42 +0000254
Tim Petersb07352e2001-09-08 01:25:47 +0000255What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000256Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000257===========================
258
Guido van Rossum808eea72001-09-25 04:15:41 +0000259Type/class unification and new-style classes
260
261- pydoc and inspect are now aware of new-style classes;
262 e.g. help(list) at the interactive prompt now shows proper
263 documentation for all operations on list objects.
264
265- Applications using Jim Fulton's ExtensionClass module can now safely
266 be used with Python 2.2. In particular, Zope 2.4.1 now works with
267 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
268 examples also work again. It is hoped that Gtk and Boost also work
269 with 2.2a4 and beyond. (If you can confirm this, please write
270 webmaster@python.org; if there are still problems, please open a bug
271 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000272
Tim Peters66c1a522001-09-24 21:17:50 +0000273- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
274 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
275 in the constructed property object. fget, fset and fdel weren't
276 discoverable from Python in 2.2a3. __doc__ is new, and allows to
277 associate a docstring with a property.
278
Guido van Rossum808eea72001-09-25 04:15:41 +0000279- Comparison overloading is now more completely implemented. For
280 example, a str subclass instance can properly be compared to a str
281 instance, and it can properly overload comparison. Ditto for most
282 other built-in object types.
283
284- The repr() of new-style classes has changed; instead of <type
285 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
286 *except* for built-in types, which are still rendered as <type
287 'Foo'> (to avoid upsetting existing code that might parse or
288 otherwise rely on repr() of certain type objects).
289
290- The repr() of new-style objects is now always <Foo object at XXX>;
291 previously, it was sometimes <Foo instance at XXX>.
292
293- For new-style classes, what was previously called __getattr__ is now
294 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000295 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000296 one in classic classes is defined which is called only if regular
297 attribute access raises AttributeError; to catch *all* attribute
298 access, you can use __getattribute__ (for new-style classes). If
299 both are defined, __getattribute__ is called first, and if it raises
300 AttributeError, __getattr__ is called.
301
302- The __class__ attribute of new-style objects can be assigned to.
303 The new class must have the same C-level object layout as the old
304 class.
305
306- The builtin file type can be subclassed now. In the usual pattern,
307 "file" is the name of the builtin type, and file() is a new builtin
308 constructor, with the same signature as the builtin open() function.
309 file() is now the preferred way to open a file.
310
311- Previously, __new__ would only see sequential arguments passed to
312 the type in a constructor call; __init__ would see both sequential
313 and keyword arguments. This made no sense whatsoever any more, so
314 now both __new__ and __init__ see all arguments.
315
316- Previously, hash() applied to an instance of a subclass of str or
317 unicode always returned 0. This has been repaired.
318
319- Previously, an operation on an instance of a subclass of an
320 immutable type (int, long, float, complex, tuple, str, unicode),
321 where the subtype didn't override the operation (and so the
322 operation was handled by the builtin type), could return that
323 instance instead a value of the base type. For example, if s was of
324 a str sublass type, s[:] returned s as-is. Now it returns a str
325 with the same value as s.
326
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000327- Provisional support for pickling new-style objects has been added.
328
Guido van Rossum808eea72001-09-25 04:15:41 +0000329Core
330
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000331- file.writelines() now accepts any iterable object producing strings.
332
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000333- PyUnicode_FromEncodedObject() now works very much like
334 PyObject_Str(obj) in that it tries to use __str__/tp_str
335 on the object if the object is not a string or buffer. This
336 makes unicode() behave like str() when applied to non-string/buffer
337 objects.
338
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000339- PyFile_WriteObject now passes Unicode objects to the file's write
340 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000341 of a print statement must support Unicode objects, i.e. they must
342 at least convert them into ASCII strings.
343
Guido van Rossum624c8af2001-09-18 15:21:04 +0000344- Thread scheduling on Solaris should be improved; it is no longer
345 necessary to insert a small sleep at the start of a thread in order
346 to let other runnable threads be scheduled.
347
Tim Petersb07352e2001-09-08 01:25:47 +0000348Library
349
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000350- StringIO.StringIO instances and cStringIO.StringIO instances support
351 read character buffer compatible objects for their .write() methods.
352 These objects are converted to strings and then handled as such
353 by the instances.
354
Barry Warsaw2f600732001-09-24 04:28:10 +0000355- The "email" package has been added. This is basically a port of the
356 mimelib package <http://sf.net/projects/mimelib> with API changes
357 and some implementations updated to use iterators and generators.
358
Tim Peters8a9c2842001-09-22 21:30:22 +0000359- difflib.ndiff() and difflib.Differ.compare() are generators now. This
360 restores the ability of Tools/scripts/ndiff.py to start producing output
361 before the entire comparison is complete.
362
Barry Warsaw58b072d2001-09-22 04:44:21 +0000363- StringIO.StringIO instances and cStringIO.StringIO instances support
364 iteration just like file objects (i.e. their .readline() method is
365 called for each iteration until it returns an empty string).
366
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000367- The codecs module has grown four new helper APIs to access
368 builtin codecs: getencoder(), getdecoder(), getreader(),
369 getwriter().
370
Guido van Rossum624c8af2001-09-18 15:21:04 +0000371- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
372 simplifies writing XML RPC servers.
373
Barry Warsaw647d5e82001-09-28 17:01:02 +0000374- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000375 after interpretation of symbolic links. On non-Unix systems, this
376 is an alias for os.path.abspath().
377
Tim Peters16a77ad2001-09-08 04:00:12 +0000378- operator.indexOf() (PySequence_Index() in the C API) now works with any
379 iterable object.
380
Guido van Rossum624c8af2001-09-18 15:21:04 +0000381- smtplib now supports various authentication and security features of
382 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000383
Guido van Rossum624c8af2001-09-18 15:21:04 +0000384- hmac: a new module implementing keyed hashing for message
385 authentication.
386
387- mimetypes now recognizes more extensions and file types. At the
388 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000389
Guido van Rossum624c8af2001-09-18 15:21:04 +0000390- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000391 Python 2.2 bytecode generation. It has also been promoted from a
392 Tool to a standard library package. (Tools/compiler still exists as
393 a sample driver.)
394
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000395Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000396
Tim Petersb07352e2001-09-08 01:25:47 +0000397Build
398
Guido van Rossum624c8af2001-09-18 15:21:04 +0000399- Large file support (LFS) is now automatic when the platform supports
400 it; no more manual configuration tweaks are needed. On Linux, at
401 least, it's possible to have a system whose C library supports large
402 files but whose kernel doesn't; in this case, large file support is
403 still enabled but doesn't do you any good unless you upgrade your
404 kernel or share your Python executable with another system whose
405 kernel has large file support.
406
407- The configure script now supplies plausible defaults in a
408 cross-compilation environment. This doesn't mean that the supplied
409 values are always correct, or that cross-compilation now works
410 flawlessly -- but it's a first step (and it shuts up most of
411 autoconf's warnings about AC_TRY_RUN).
412
413- The Unix build is now a bit less chatty, courtesy of the parser
414 generator. The build is completely silent (except for errors) when
415 using "make -s", thanks to a -q option to setup.py.
416
Tim Petersb07352e2001-09-08 01:25:47 +0000417C API
418
Guido van Rossum624c8af2001-09-18 15:21:04 +0000419- The "structmember" API now supports some new flag bits to deny read
420 and/or write access to attributes in restricted execution mode.
421
Tim Petersb07352e2001-09-08 01:25:47 +0000422New platforms
423
Guido van Rossum624c8af2001-09-18 15:21:04 +0000424- Compaq's iPAQ handheld, running the "familiar" Linux distribution
425 (http://familiar.handhelds.org).
426
Tim Petersb07352e2001-09-08 01:25:47 +0000427Tests
428
Tim Peters8a9c2842001-09-22 21:30:22 +0000429- The "classic" standard tests, which work by comparing stdout to
430 an expected-output file under Lib/test/output/, no longer stop at
431 the first mismatch. Instead the test is run to completion, and a
432 variant of ndiff-style comparison is used to report all differences.
433 This is much easier to understand than the previous style of reporting.
434
435- The unittest-based standard tests now use regrtest's test_main()
436 convention, instead of running as a side-effect of merely being
437 imported. This allows these tests to be run in more natural and
438 flexible ways as unittests, outside the regrtest framework.
439
440- regrtest.py is much better integrated with unittest and doctest now,
441 especially in regard to reporting errors.
442
Tim Petersb07352e2001-09-08 01:25:47 +0000443Windows
444
Guido van Rossum624c8af2001-09-18 15:21:04 +0000445- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000446 that support it (NTFS under Windows 2000). See "What's New in
447 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000448
Tim Petersb07352e2001-09-08 01:25:47 +0000449
Tim Petersedc99312001-08-22 21:36:50 +0000450What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000451Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000452===========================
453
454Core
455
Tim Peters9fffa3e2001-09-04 05:14:19 +0000456- Conversion of long to float now raises OverflowError if the long is too
457 big to represent as a C double.
458
Tim Peters32f453e2001-09-03 08:35:41 +0000459- The 3-argument builtin pow() no longer allows a third non-None argument
460 if either of the first two arguments is a float, or if both are of
461 integer types and the second argument is negative (in which latter case
462 the arguments are converted to float, so this is really the same
463 restriction).
464
Tim Peters5d2b77c2001-09-03 05:47:38 +0000465- The builtin dir() now returns more information, and sometimes much
466 more, generally naming all attributes of an object, and all attributes
467 reachable from the object via its class, and from its class's base
468 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
469 an empty list. In 2.2a3,
470
471 >>> dir([])
472 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
473 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
474 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
475 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
476 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
477 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
478 'reverse', 'sort']
479
480 dir(module) continues to return only the module's attributes, though.
481
Tim Petersbdee63f2001-09-02 03:40:59 +0000482- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000483 than raising OverflowError. This is a partial implementation of PEP
484 237. You can use -Wdefault::OverflowWarning to enable a warning for
485 this situation, and -Werror::OverflowWarning to revert to the old
486 OverflowError exception.
487
Guido van Rossum61c345f2001-09-04 03:26:15 +0000488- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000489 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000490 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
491 -Qold, meaning the / operator has its classic meaning and no
492 warnings are issued. Using -Qwarn issues a run-time warning about
493 all uses of classic division for int and long arguments; -Qwarnall
494 also warns about classic division for float and complex arguments
495 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
496 new division by default, but only in the __main__ module. You can
497 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
498 __main__ module new division, and warns about classic division
499 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000500
Tim Petersbdee63f2001-09-02 03:40:59 +0000501- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000502 long, float, str, unicode, and tuple. (The types complex, list and
503 dictionary can also be subclassed; this was introduced earlier.)
504 Note that restrictions apply when subclassing immutable built-in
505 types: you can only affect the value of the instance by overloading
506 __new__. You can add mutable attributes, and the subclass instances
507 will have a __dict__ attribute, but you cannot change the "value"
508 (as implemented by the base class) of an immutable subclass instance
509 once it is created.
510
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000511- The dictionary constructor now takes an optional argument, a
512 mapping-like object, and initializes the dictionary from its
513 (key, value) pairs.
514
Tim Petersbdee63f2001-09-02 03:40:59 +0000515- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000516 "cooperative super calls" in a multiple inheritance setting. For an
517 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
518
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000519- A new built-in type, property, has been added. This enables the
520 creation of "properties". These are attributes implemented by
521 getter and setter functions (or only one of these for read-only or
522 write-only attributes), without the need to override __getattr__.
523 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000524
Tim Petersbdee63f2001-09-02 03:40:59 +0000525- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000526 liberalized, to allow leading zeroes. Examples of literals now
527 legal that were SyntaxErrors before:
528
529 00.0 0e3 0100j 07.5 00000000000000000008.
530
Tim Petersbdee63f2001-09-02 03:40:59 +0000531- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000532 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
533
Tim Petersedc99312001-08-22 21:36:50 +0000534Library
535
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000536- telnetlib includes symbolic names for the options, and support for
537 setting an option negotiation callback.
538
Tim Petersa40c7932001-09-05 22:36:56 +0000539- The new C standard no longer requires that math libraries set errno to
540 ERANGE on overflow. For platform libraries that exploit this new
541 freedom, Python's overflow-checking was wholly broken. A new overflow-
542 checking scheme attempts to repair that, but may not be reliable on all
543 platforms (C doesn't seem to provide anything both useful and portable
544 in this area anymore).
545
Martin v. Löwis44f86962001-09-05 13:44:54 +0000546- Asynchronous timeout actions are available through the new class
547 threading.Timer.
548
Tim Peters78526162001-09-05 00:53:45 +0000549- math.log and math.log10 now return sensible results for even huge
550 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
551
Tim Petersbdee63f2001-09-02 03:40:59 +0000552- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000553 currently held. See the docs for the imp module.
554
Tim Petersbdee63f2001-09-02 03:40:59 +0000555- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000556 dumps containing ints written on platforms where Python ints are 8 bytes.
557 When read on a box where Python ints are 4 bytes, such values are
558 converted to Python longs.
559
Tim Petersbdee63f2001-09-02 03:40:59 +0000560- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000561 code objects is no longer allowed. This plugs a security hole.
562
Steve Purcell6091cd62001-09-06 16:05:17 +0000563- unittest.TestResult instances no longer store references to tracebacks
564 generated by test failures. This prevents unexpected dangling references
565 to objects that should be garbage collected between tests.
566
Tim Petersedc99312001-08-22 21:36:50 +0000567Tools
568
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000569- Tools/scripts/fixdiv.py has been added which can be used to fix
570 division operators as per PEP 238.
571
Tim Petersedc99312001-08-22 21:36:50 +0000572Build
573
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000574- If you are an adventurous person using Mac OS X you may want to look at
575 Mac/OSX. There is a Makefile there that will build Python as a real Mac
576 application, which can be used for experimenting with Carbon or Cocoa.
577 Discussion of this on pythonmac-sig, please.
578
Tim Peters7eea37e2001-09-04 22:08:56 +0000579C API
580
581- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000582
Tim Peters9fffa3e2001-09-04 05:14:19 +0000583- Note that PyLong_AsDouble can fail! This has always been true, but no
584 callers checked for it. It's more likely to fail now, because overflow
585 errors are properly detected now. The proper way to check:
586
587 double x = PyLong_AsDouble(some_long_object);
588 if (x == -1.0 && PyErr_Occurred()) {
589 /* The conversion failed. */
590 }
591
Tim Petersbdee63f2001-09-02 03:40:59 +0000592- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000593 compile but will not participate in GC. To upgrade an extension
594 module:
595
596 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000597
Neil Schemenauer4042c692001-08-30 15:38:01 +0000598 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
599 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000600
Neil Schemenauer4042c692001-08-30 15:38:01 +0000601 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
602 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000603
Neil Schemenauer4042c692001-08-30 15:38:01 +0000604 - remove PyGC_HEAD_SIZE from object size calculations
605
606 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
607
Tim Petersbdee63f2001-09-02 03:40:59 +0000608- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000609 These can be used safely to construct string objects from a
610 sprintf-style format string (similar to the format string supported
611 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000612
Tim Petersedc99312001-08-22 21:36:50 +0000613New platforms
614
Tim Petersb7da0902001-09-02 23:01:43 +0000615- Stephen Hansen contributed patches sufficient to get a clean compile
616 under Borland C (Windows), but he reports problems running it and ran
617 out of time to complete the port. Volunteers? Expect a MemoryError
618 when importing the types module; this is probably shallow, and
619 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000620
Tim Petersedc99312001-08-22 21:36:50 +0000621Tests
622
623Windows
624
Tim Peters6e13a562001-09-06 00:32:15 +0000625- Large file support is now enabled on Win32 platforms as well as on
626 Win64. This means that, for example, you can use f.tell() and f.seek()
627 to manipulate files larger than 2 gigabytes (provided you have enough
628 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000629 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
630 filesize limit, and large file support makes no difference there.
631 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
632 NTFS has no practical limit on file size, and files of any size can be
633 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000634
Tim Petersbdee63f2001-09-02 03:40:59 +0000635- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000636 points to command.com (patch from Brian Quinlan).
637
Tim Petersedc99312001-08-22 21:36:50 +0000638
Tim Peters20f51a72001-07-21 02:31:40 +0000639What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000640Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000641===========================
642
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000643Build
644
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000645- Tim Peters developed a brand new Windows installer using Wise 8.1,
646 generously donated to us by Wise Solutions.
647
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000648- configure supports a new option --enable-unicode, with the values
649 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
650 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000651
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000652- A new configure option --enable-framework builds a Mac OS X framework,
653 which "make frameworkinstall" will install. This provides a starting
654 point for more mac-like functionality, join pythonmac-sig@python.org
655 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000656
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000657- The NeXT platform is no longer supported.
658
659- The `new' module is now statically linked.
660
Tim Peters0afb6092001-08-15 06:06:44 +0000661Tools
662
663- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000664 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000665 the module docstring for details.
666
Tim Peters20f51a72001-07-21 02:31:40 +0000667Tests
668
Tim Peters5e824c32001-08-12 22:25:01 +0000669- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000670 platforms, allowing to give clearer test result output. regrtest
671 also has optional --use/-u switch to run normally disabled tests
672 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000673
Tim Peters20f51a72001-07-21 02:31:40 +0000674- Several new tests in the standard test suite, with special thanks to
675 Nick Mathewson.
676
677Core
678
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000679- The floor division operator // has been added as outlined in PEP
680 238. The / operator still provides classic division (and will until
681 Python 3.0) unless "from __future__ import division" is included, in
682 which case the / operator will provide true division. The operator
683 module provides truediv() and floordiv() functions. Augmented
684 assignment variants are included, as are the equivalent overloadable
685 methods and C API methods. See the PEP for a full discussion:
686 <http://python.sf.net/peps/pep-0238.html>
687
Tim Peters6cd6a822001-08-17 22:11:27 +0000688- Future statements are now effective in simulated interactive shells
689 (like IDLE). This should "just work" by magic, but read Michael
690 Hudson's "Future statements in simulated shells" PEP 264 for full
691 details: <http://python.sf.net/peps/pep-0264.html>.
692
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000693- The type/class unification (PEP 252-253) was integrated into the
694 trunk and is not so tentative any more (the exact specification of
695 some features is still tentative). A lot of work has done on fixing
696 bugs and adding robustness and features (performance still has to
697 come a long way).
698
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000699- Warnings about a mismatch in the Python API during extension import
700 now use the Python warning framework (which makes it possible to
701 write filters for these warnings).
702
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000703- A function's __dict__ (aka func_dict) will now always be a
704 dictionary. It used to be possible to delete it or set it to None,
705 but now both actions raise TypeErrors. It is still legal to set it
706 to a dictionary object. Getting func.__dict__ before any attributes
707 have been assigned now returns an empty dictionary instead of None.
708
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000709- A new command line option, -E, was added which disables the use of
710 all environment variables, or at least those that are specifically
711 significant to Python. Usually those have a name starting with
712 "PYTHON". This was used to fix a problem where the tests fail if
713 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
714 older distribution.
715
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000716Library
717
Tim Peters5e824c32001-08-12 22:25:01 +0000718- New class Differ and new functions ndiff() and restore() in difflib.py.
719 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000720 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000721
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000722- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
723 value using the minimal quoting required for the value; more
724 reliable than using xml.sax.saxutils.escape() for attribute values.
725
726- Readline completion support for cmd.Cmd was added.
727
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000728- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
729
730- Added function threading.BoundedSemaphore()
731
732- Added Ka-Ping Yee's cgitb.py module.
733
734- The `new' module now exposes the CO_xxx flags.
735
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000736New platforms
737
738C API
739
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000740- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
741 which provide a cross-platform implementations for the
742 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
743 the standard sprintf() and vsprintf() C lib APIs, these versions
744 apply bounds checking on the used buffer which enhances protection
745 against buffer overruns.
746
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000747- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000748 and extensions using different Unicode widths is rendered next to
749 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000750 will result in an ImportError. Unicode extensions writers must make
751 sure to check the Unicode width compatibility in their extensions by
752 using at least one of the mangled Unicode APIs in the extension.
753
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000754- Two new flags METH_NOARGS and METH_O are available in method definition
755 tables to simplify implementation of methods with no arguments and a
756 single untyped argument. Calling such methods is more efficient than
757 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
758 deprecated.
759
Tim Petersc1731372001-08-04 08:12:36 +0000760Windows
761
762- "import module" now compiles module.pyw if it exists and nothing else
763 relevant is found.
764
Tim Peters20f51a72001-07-21 02:31:40 +0000765
Guido van Rossum55a78992001-07-17 17:22:32 +0000766What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000767===========================
768
769Core
Tim Petersa814db52001-05-14 07:05:58 +0000770
Tim Peters6d6c1a32001-08-02 04:15:00 +0000771- TENTATIVELY, a large amount of code implementing much of what's
772 described in PEP 252 (Making Types Look More Like Classes) and PEP
773 253 (Subtyping Built-in Types) was added. This will be released
774 with Python 2.2a1. Documentation will be provided separately
775 through http://www.python.org/2.2/. The purpose of releasing this
776 with Python 2.2a1 is to test backwards compatibility. It is
777 possible, though not likely, that a decision is made not to release
778 this code as part of 2.2 final, if any serious backwards
779 incompapatibilities are found during alpha testing that cannot be
780 repaired.
781
Guido van Rossum55a78992001-07-17 17:22:32 +0000782- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000783 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000784 more 'yield' statements. See PEP 255. Since this adds a new
785 keyword to the language, this feature must be enabled by including a
786 future statement: "from __future__ import generators" (see PEP 236).
787 Generators will become a standard feature in a future release
788 (probably 2.3). Without this future statement, 'yield' remains an
789 ordinary identifier, but a warning is issued each time it is used.
790 (These warnings currently don't conform to the warnings framework of
791 PEP 230; we intend to fix this in 2.2a2.)
792
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000793- The UTF-16 codec was modified to be more RFC compliant. It will now
794 only remove BOM characters at the start of the string and then
795 only if running in native mode (UTF-16-LE and -BE won't remove a
796 leading BMO character).
797
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000798- Strings now have a new method .decode() to complement the already
799 existing .encode() method. These two methods provide direct access
800 to the corresponding decoders and encoders of the registered codecs.
801
802 To enhance the usability of the .encode() method, the special
803 casing of Unicode object return values was dropped (Unicode objects
804 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000805
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000806 Both methods will now return whatever the codec in charge of the
807 requested encoding returns as object, e.g. Unicode codecs will
808 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
809 will return u"äöü"). This enables codec writer to create codecs
810 for various simple to use conversions.
811
812 New codecs were added to demonstrate these new features (the .encode()
813 and .decode() columns indicate the type of the returned objects):
814
815 Name | .encode() | .decode() | Description
816 ----------------------------------------------------------------------
817 uu | string | string | UU codec (e.g. for email)
818 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000819 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000820 zlib | string | string | zlib compression
821 hex | string | string | 2-byte hex codec
822 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
823
Mark Hammond2a0af792001-05-14 03:09:36 +0000824- Some operating systems now support the concept of a default Unicode
825 encoding for file system operations. Notably, Windows supports 'mbcs'
826 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000827 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000828 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000829
830 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000831 functions that return filenames (such as os.listdir()) to return Python
832 string objects pre-encoded using the default file system encoding for
833 the platform. As this encoding is likely to be different from Python's
834 default encoding, converting this name to a Unicode object before passing
835 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000836 would attempt to use its default encoding (generally ASCII) rather than
837 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000838
Tim Petersa814db52001-05-14 07:05:58 +0000839 In general, this change simply removes surprises when working with
840 Unicode and the file system, making these operations work as you expect,
841 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000842 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000843
Tim Peters61dff2b2001-05-08 15:43:37 +0000844- Float (and complex) literals in source code were evaluated to full
845 precision only when running from a .py file; the same code loaded from a
846 .pyc (or .pyo) file could suffer numeric differences starting at about the
847 12th significant decimal digit. For example, on a machine with IEEE-754
848 floating arithmetic,
849
850 x = 9007199254740992.0
851 print long(x)
852
853 printed 9007199254740992 if run directly from .py, but 9007199254740000
854 if from a compiled (.pyc or .pyo) file. This was due to marshal using
855 str(float) instead of repr(float) when building code objects. marshal
856 now uses repr(float) instead, which should reproduce floats to full
857 machine precision (assuming the platform C float<->string I/O conversion
858 functions are of good quality).
859
860 This may cause floating-point results to change in some cases, and
861 usually for the better, but may also cause numerically unstable
862 algorithms to break.
863
Tim Peters2f228e72001-05-13 00:19:31 +0000864- The implementation of dicts suffers fewer collisions, which has speed
865 benefits. However, the order in which dict entries appear in dict.keys(),
866 dict.values() and dict.items() may differ from previous releases for a
867 given dict. Nothing is defined about this order, so no program should
868 rely on it. Nevertheless, it's easy to write test cases that rely on the
869 order by accident, typically because of printing the str() or repr() of a
870 dict to an "expected results" file. See Lib/test/test_support.py's new
871 sortdict(dict) function for a simple way to display a dict in sorted
872 order.
873
Tim Peters7a3bfc32001-06-12 01:22:22 +0000874- Many other small changes to dicts were made, resulting in faster
875 operation along the most common code paths.
876
Guido van Rossum10315822001-05-01 20:54:30 +0000877- Dictionary objects now support the "in" operator: "x in dict" means
878 the same as dict.has_key(x).
879
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000880- The update() method of dictionaries now accepts generic mapping
881 objects. Specifically the argument object must support the .keys()
882 and __getitem__() methods. This allows you to say, for example,
883 {}.update(UserDict())
884
Guido van Rossum10315822001-05-01 20:54:30 +0000885- Iterators were added; this is a generalized way of providing values
886 to a for loop. See PEP 234. There's a new built-in function iter()
887 to return an iterator. There's a new protocol to get the next value
888 from an iterator using the next() method (in Python) or the
889 tp_iternext slot (in C). There's a new protocol to get iterators
890 using the __iter__() method (in Python) or the tp_iter slot (in C).
891 Iterating (i.e. a for loop) over a dictionary generates its keys.
892 Iterating over a file generates its lines.
893
Tim Petersf553f892001-05-01 20:45:31 +0000894- The following functions were generalized to work nicely with iterator
895 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000896 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000897 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
898 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000899 join() method of strings
900 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000901 'x in y' and 'x not in y' (PySequence_Contains() in C API)
902 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000903 right-hand side of assignment statements with multiple targets, such as
904 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000905
Tim Petersd85e1022001-05-11 21:51:48 +0000906- Accessing module attributes is significantly faster (for example,
907 random.random or os.path or yourPythonModule.yourAttribute).
908
Tim Peterse63415e2001-05-08 04:38:29 +0000909- Comparing dictionary objects via == and != is faster, and now works even
910 if the keys and values don't support comparisons other than ==.
911
Tim Peters95bf9392001-05-10 08:32:44 +0000912- Comparing dictionaries in ways other than == and != is slower: there were
913 insecurities in the dict comparison implementation that could cause Python
914 to crash if the element comparison routines for the dict keys and/or
915 values mutated the dicts. Making the code bulletproof slowed it down.
916
Tim Peterseb28ef22001-06-02 05:27:19 +0000917- Collisions in dicts are resolved via a new approach, which can help
918 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000919 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000920 faster now. Thanks to Christian Tismer for pointing out the cause and
921 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000922
Tim Peters52e155e2001-06-16 05:42:57 +0000923- repr() is much faster for large containers (dict, list, tuple).
924
925
Tim Petersa814db52001-05-14 07:05:58 +0000926Library
927
Fred Drake960fdf92001-07-20 18:38:26 +0000928- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
929 were added to the string module. These a locale-indenpendent
930 constants, unlike letters, lowercase, and uppercase. These are now
931 use in appropriate locations in the standard library.
932
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000933- The flags used in dlopen calls can now be configured using
934 sys.setdlopenflags and queried using sys.getdlopenflags.
935
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000936- Fredrik Lundh's xmlrpclib is now a standard library module. This
937 provides full client-side XML-RPC support. In addition,
938 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
939 one asyncore-based). Thanks to Eric Raymond for the documentation.
940
Guido van Rossum643d3912001-07-05 14:46:25 +0000941- The xrange() object is simplified: it no longer supports slicing,
942 repetition, comparisons, efficient 'in' checking, the tolist()
943 method, or the start, stop and step attributes. See PEP 260.
944
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000945- A new function fnmatch.filter to filter lists of file names was added.
946
Barry Warsawffd674d2001-05-22 16:00:10 +0000947- calendar.py uses month and day names based on the current locale.
948
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000949- strop is now *really* obsolete (this was announced before with 1.6),
950 and issues DeprecationWarning when used (except for the four items
951 that are still imported into string.py).
952
Tim Petersa814db52001-05-14 07:05:58 +0000953- Cookie.py now sorts key+value pairs by key in output strings.
954
955- pprint.isrecursive(object) didn't correctly identify recursive objects.
956 Now it does.
957
Tim Peters95b3f782001-05-14 18:39:41 +0000958- pprint functions now much faster for large containers (tuple, list, dict).
959
Tim Peters7b9542a2001-06-10 23:40:19 +0000960- New 'q' and 'Q' format codes in the struct module, corresponding to C
961 types "long long" and "unsigned long long" (on Windows, __int64). In
962 native mode, these can be used only when the platform C compiler supports
963 these types (when HAVE_LONG_LONG is #define'd by the Python config
964 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000965 In standard mode, 'q' and 'Q' are supported on all platforms, and are
966 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000967
Guido van Rossum83213cc2001-06-12 16:48:52 +0000968- The site module installs a new built-in function 'help' that invokes
969 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
970 it displays a message reminding the user to use 'help()' or
971 'help(object)'.
972
Tim Petersa814db52001-05-14 07:05:58 +0000973Tests
974
975- New test_mutants.py runs dict comparisons where the key and value
976 comparison operators mutute the dicts randomly during comparison. This
977 rapidly causes Python to crash under earlier releases (not for the faint
978 of heart: it can also cause Win9x to freeze or reboot!).
979
980- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000981 pprint.isreadable() return sensible results. Also verifies that simple
982 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000983
Tim Peters4324aa32001-05-28 22:30:08 +0000984C API
985
986- Removed the unused last_is_sticky argument from the internal
987 _PyTuple_Resize(). If this affects you, you were cheating.
988
989
Guido van Rossum55a78992001-07-17 17:22:32 +0000990======================================================================
991
992
Guido van Rossumffe13be2001-04-16 18:46:45 +0000993What's New in Python 2.1 (final)?
994=================================
995
996We only changed a few things since the last release candidate, all in
997Python library code:
998
999- A bug in the locale module was fixed that affected locales which
1000 define no grouping for numeric formatting.
1001
1002- A few bugs in the weakref module's implementations of weak
1003 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1004 and the test suite was updated to check for these bugs.
1005
1006- An old bug in the os.path.walk() function (introduced in Python
1007 2.0!) was fixed: a non-existent file would cause an exception
1008 instead of being ignored.
1009
1010- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1011 PyChecker.
1012
1013
Guido van Rossum5b08f132001-04-16 02:05:23 +00001014What's New in Python 2.1c2?
1015===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001016
Guido van Rossum5b08f132001-04-16 02:05:23 +00001017A flurry of small changes, and one showstopper fixed in the nick of
1018time made it necessary to release another release candidate. The list
1019here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001020
Guido van Rossum5b08f132001-04-16 02:05:23 +00001021Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001022
Guido van Rossum5b08f132001-04-16 02:05:23 +00001023- Tim discovered a nasty bug in the dictionary code, caused by
1024 PyDict_Next() calling dict_resize(), and the GC code's use of
1025 PyDict_Next() violating an assumption in dict_items(). This was
1026 fixed with considerable amounts of band-aid, but the net effect is a
1027 saner and more robust implementation.
1028
1029- Made a bunch of symbols static that were accidentally global.
1030
1031Build and Ports
1032
1033- The setup.py script didn't check for a new enough version of zlib
1034 (1.1.3 is needed). Now it does.
1035
1036- Changed "make clean" target to also remove shared libraries.
1037
1038- Added a more general warning about the SGI Irix optimizer to README.
1039
1040Library
1041
1042- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1043 omitted the slash between host and file.html.
1044
1045- The mailbox module's _Mailbox class contained a completely broken
1046 and undocumented seek() method. Ripped it out.
1047
1048- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1049 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1050
1051- Fixed a few last-minute bugs in unittest.
1052
1053Extensions
1054
1055- Reverted the patch to the OpenSSL code in socketmodule.c to support
1056 RAND_status() and the EGD, and the subsequent patch that tried to
1057 fix it for pre-0.9.5 versions; the problem with the patch is that on
1058 some systems it issues a warning whenever socket is imported, and
1059 that's unacceptable.
1060
1061Tests
1062
1063- Fixed the pickle tests to work with "import test.test_pickle".
1064
1065- Tweaked test_locale.py to actually run the test Windows.
1066
1067- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1068 not "wb" (which is not a valid mode at all).
1069
1070- Fix pstats browser crashes. Import readline if it exists to make
1071 the user interface nicer.
1072
1073- Add "import thread" to the top of test modules that import the
1074 threading module (test_asynchat and test_threadedtempfile). This
1075 prevents test failures caused by a broken threading module resulting
1076 from a previously caught failed import.
1077
1078- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1079 needed on some platforms (e.g. Solaris 8) when the tests are run
1080 twice in succession.
1081
1082- Skip rather than fail test_sunaudiodev if no audio device is found.
1083
1084
1085What's New in Python 2.1c1?
1086===========================
1087
1088This list was significantly updated when 2.1c2 was released; the 2.1c1
1089release didn't mention most changes that were actually part of 2.1c1:
1090
1091Legal
1092
1093- Copyright was assigned to the Python Software Foundation (PSF) and a
1094 PSF license (very similar to the CNRI license) was added.
1095
1096- The CNRI copyright notice was updated to include 2001.
1097
1098Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001099
Guido van Rossumc9932722001-04-12 02:31:27 +00001100- After a public outcry, assignment to __debug__ is no longer illegal;
1101 instead, a warning is issued. It will become illegal in 2.2.
1102
Guido van Rossum5b08f132001-04-16 02:05:23 +00001103- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1104 "%#x" now always prepends "0x", even if the value is zero.
1105
1106- Fixed some nits in the bytecode compiler.
1107
1108- Fixed core dumps when calling certain kinds of non-functions.
1109
1110- Fixed various core dumps caused by reference count bugs.
1111
1112Build and Ports
1113
1114- Use INSTALL_SCRIPT to install script files.
1115
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001116- New port: SCO Unixware 7, by Billy G. Allie.
1117
Guido van Rossum5b08f132001-04-16 02:05:23 +00001118- Updated RISCOS port.
1119
1120- Updated BeOS port and notes.
1121
1122- Various other porting problems resolved.
1123
1124Library
1125
1126- The TERMIOS and SOCKET modules are now truly obsolete and
1127 unnecessary. Their symbols are incorporated in the termios and
1128 socket modules.
1129
1130- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1131 better tests for pickling.
1132
1133- threading: make Condition.wait() robust against KeyboardInterrupt.
1134
1135- zipfile: add support to zipfile to support opening an archive
1136 represented by an open file rather than a file name. Fix bug where
1137 the archive was not properly closed. Fixed a bug in this bugfix
1138 where flush() was called for a read-only file.
1139
1140- imputil: added an uninstall() method to the ImportManager.
1141
1142- Canvas: fixed bugs in lower() and tkraise() methods.
1143
1144- SocketServer: API change (added overridable close_request() method)
1145 so that the TCP server can explicitly close the request.
1146
1147- pstats: Eric Raymond added a simple interactive statistics browser,
1148 invoked when the module is run as a script.
1149
1150- locale: fixed a problem in format().
1151
1152- webbrowser: made it work when the BROWSER environment variable has a
1153 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1154 KDE 2. Fixed some other nits.
1155
1156- unittest: changes to allow using a different exception than
1157 AssertionError, and added a few more function aliases. Some other
1158 small changes.
1159
1160- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1161
1162- asynchat: fixed a critical bug in asynchat that slipped through the
1163 2.1b2 release. Fixed another rare bug.
1164
1165- Fix some unqualified except: clauses (always a bad code example).
1166
1167XML
1168
1169- pyexpat: new API get_version_string().
1170
1171- Fixed some minidom bugs.
1172
1173Extensions
1174
1175- Fixed a core dump in _weakref. Removed the weakref.mapping()
1176 function (it adds nothing to the API).
1177
1178- Rationalized the use of header files in the readline module, to make
1179 it compile (albeit with some warnings) with the very recent readline
1180 4.2, without breaking for earlier versions.
1181
1182- Hopefully fixed a buffering problem in linuxaudiodev.
1183
1184- Attempted a fix to make the OpenSSL support in the socket module
1185 work again with pre-0.9.5 versions of OpenSSL.
1186
1187Tests
1188
1189- Added a test case for asynchat and asyncore.
1190
1191- Removed coupling between tests where one test failing could break
1192 another.
1193
1194Tools
1195
1196- Ping added an interactive help browser to pydoc, fixed some nits
1197 in the rest of the pydoc code, and added some features to his
1198 inspect module.
1199
1200- An updated python-mode.el version 4.1 which integrates Ken
1201 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1202 much nicer in XEmacs and Emacs. When stepping through your program
1203 with pdb, in either the shell window or the *Python* window, the
1204 source file and line will be tracked by an arrow. Very cool!
1205
1206- IDLE: syntax warnings in interactive mode are changed into errors.
1207
1208- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001209 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001210
1211- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001212
Barry Warsaw11e89c72001-04-11 20:37:57 +00001213
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001214What's New in Python 2.1 beta 2?
1215================================
1216
Guido van Rossum053ae352001-03-22 14:17:21 +00001217(Unlisted are many fixed bugs, more documentation, etc.)
1218
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001219Core language, builtins, and interpreter
1220
Guido van Rossum053ae352001-03-22 14:17:21 +00001221- The nested scopes work (enabled by "from __future__ import
1222 nested_scopes") is completed; in particular, the future now extends
1223 into code executed through exec, eval() and execfile(), and into the
1224 interactive interpreter.
1225
1226- When calling a base class method (e.g. BaseClass.__init__(self)),
1227 this is now allowed even if self is not strictly spoken a class
1228 instance (e.g. when using metaclasses or the Don Beaudry hook).
1229
1230- Slice objects are now comparable but not hashable; this prevents
1231 dict[:] from being accepted but meaningless.
1232
1233- Complex division is now calculated using less braindead algorithms.
1234 This doesn't change semantics except it's more likely to give useful
1235 results in extreme cases. Complex repr() now uses full precision
1236 like float repr().
1237
1238- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1239
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001240- It is illegal to assign to the name __debug__, which is set when the
1241 interpreter starts. It is effectively a compile-time constant.
1242
1243- A warning will be issued if a global statement for a variable
1244 follows a use or assignment of that variable.
1245
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001246Standard library
1247
Guido van Rossum053ae352001-03-22 14:17:21 +00001248- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1249 inspired by JUnit), is now part of the standard library. You now
1250 have a choice of two testing frameworks: unittest requires you to
1251 write testcases as separate code, doctest gathers them from
1252 docstrings. Both approaches have their advantages and
1253 disadvantages.
1254
1255- A new module Tix was added, which wraps the Tix extension library
1256 for Tk. With that module, it is not necessary to statically link
1257 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1258 require" command. See Demo/tix/.
1259
1260- tzparse.py is now obsolete.
1261
1262- In gzip.py, the seek() and tell() methods are removed -- they were
1263 non-functional anyway, and it's better if callers can test for their
1264 existence with hasattr().
1265
1266Python/C API
1267
1268- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1269 that's already in the dictionary during a PyDict_Next() iteration.
1270 This used to fail occasionally when a dictionary resize operation
1271 could be triggered that would rehash all the keys. All other
1272 modifications to the dictionary are still off-limits during a
1273 PyDict_Next() iteration!
1274
1275- New extended APIs related to passing compiler variables around.
1276
1277- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1278 implement isinstance() and issubclass().
1279
1280- Py_BuildValue() now has a "D" conversion to create a Python complex
1281 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001282
Fred Drake4e262a92001-03-22 18:26:47 +00001283- Extensions types which support weak references must now set the
1284 field allocated for the weak reference machinery to NULL themselves;
1285 this is done to avoid the cost of checking each object for having a
1286 weakly referencable type in PyObject_INIT(), since most types are
1287 not weakly referencable.
1288
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001289- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1290 free variables and cell variables to and from the frame's f_locals.
1291
1292- Variants of several functions defined in pythonrun.h have been added
1293 to support the nested_scopes future statement. The variants all end
1294 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1295 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1296 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001297 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001298
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001299Distutils
1300
1301- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1302 into the release tree.
1303
Tim Peters0e57abf2001-05-02 07:39:38 +00001304- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001305 (an uninstaller, more customization of the installer's display)
1306
1307- from Jack Jansen: added Mac-specific code to generate a dialog for
1308 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001309 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001310 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001311
1312- added 'platforms' and 'keywords' to the set of metadata that can be
1313 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001314
1315- applied patches from Jason Tishler to make the compiler class work with
1316 Cygwin.
1317
1318
Tim Peters2fe289a2001-03-01 22:19:38 +00001319What's New in Python 2.1 beta 1?
1320================================
Tim Petersd66595f2001-02-04 03:09:53 +00001321
1322Core language, builtins, and interpreter
1323
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001324- Following an outcry from the community about the amount of code
1325 broken by the nested scopes feature introduced in 2.1a2, we decided
1326 to make this feature optional, and to wait until Python 2.2 (or at
1327 least 6 months) to make it standard. The option can be enabled on a
1328 per-module basis by adding "from __future__ import nested_scopes" at
1329 the beginning of a module (before any other statements, but after
1330 comments and an optional docstring). See PEP 236 (Back to the
1331 __future__) for a description of the __future__ statement. PEP 227
1332 (Statically Nested Scopes) has been updated to reflect this change,
1333 and to clarify the semantics in a number of endcases.
1334
1335- The nested scopes code, when enabled, has been hardened, and most
1336 bugs and memory leaks in it have been fixed.
1337
1338- Compile-time warnings are now generated for a number of conditions
1339 that will break or change in meaning when nested scopes are enabled:
1340
1341 - Using "from...import *" or "exec" without in-clause in a function
1342 scope that also defines a lambda or nested function with one or
1343 more free (non-local) variables. The presence of the import* or
1344 bare exec makes it impossible for the compiler to determine the
1345 exact set of local variables in the outer scope, which makes it
1346 impossible to determine the bindings for free variables in the
1347 inner scope. To avoid the warning about import *, change it into
1348 an import of explicitly name object, or move the import* statement
1349 to the global scope; to avoid the warning about bare exec, use
1350 exec...in... (a good idea anyway -- there's a possibility that
1351 bare exec will be deprecated in the future).
1352
1353 - Use of a global variable in a nested scope with the same name as a
1354 local variable in a surrounding scope. This will change in
1355 meaning with nested scopes: the name in the inner scope will
1356 reference the variable in the outer scope rather than the global
1357 of the same name. To avoid the warning, either rename the outer
1358 variable, or use a global statement in the inner function.
1359
Neil Schemenauera35c6882001-02-27 04:45:05 +00001360- An optional object allocator has been included. This allocator is
1361 optimized for Python objects and should be faster and use less memory
1362 than the standard system allocator. It is not enabled by default
1363 because of possible thread safety problems. The allocator is only
1364 protected by the Python interpreter lock and it is possible that some
1365 extension modules require a thread safe allocator. The object
1366 allocator can be enabled by providing the "--with-pymalloc" option to
1367 configure.
1368
Tim Petersd66595f2001-02-04 03:09:53 +00001369Standard library
1370
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001371- pyexpat now detects the expat version if expat.h defines it. A
1372 number of additional handlers are provided, which are only available
1373 since expat 1.95. In addition, the methods SetParamEntityParsing and
1374 GetInputContext of Parser objects are available with 1.95.x
1375 only. Parser objects now provide the ordered_attributes and
1376 specified_attributes attributes. A new module expat.model was added,
1377 which offers a number of additional constants if 1.95.x is used.
1378
1379- xml.dom offers the new functions registerDOMImplementation and
1380 getDOMImplementation.
1381
1382- xml.dom.minidom offers a toprettyxml method. A number of DOM
1383 conformance issues have been resolved. In particular, Element now
1384 has an hasAttributes method, and the handling of namespaces was
1385 improved.
1386
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001387- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1388 getting information about live Python code, and pydoc.py, a module
1389 for interactively converting docstrings to HTML or text.
1390 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001391 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001392 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1393 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001394
Tim Peters1eff7962001-03-01 02:31:33 +00001395- New library module difflib.py, primarily packaging the SequenceMatcher
1396 class at the heart of the popular ndiff.py file-comparison tool.
1397
1398- doctest.py (a framework for verifying Python code examples in docstrings)
1399 is now part of the std library.
1400
Tim Petersd66595f2001-02-04 03:09:53 +00001401Windows changes
1402
Guido van Rossume3955a82001-03-02 14:05:59 +00001403- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1404 small GUI that lets you browse the module docstrings using your
1405 default web browser.
1406
Tim Peters1eff7962001-03-01 02:31:33 +00001407- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1408 Platforms) is implemented. See
1409
1410 http://python.sourceforge.net/peps/pep-0235.html
1411
1412 for full details, especially the "Current Lower-Left Semantics" section.
1413 The new Windows import rules are simpler than before:
1414
1415 A. If the PYTHONCASEOK environment variable exists, same as
1416 before: silently accept the first case-insensitive match of any
1417 kind; raise ImportError if none found.
1418
1419 B. Else search sys.path for the first case-sensitive match; raise
1420 ImportError if none found.
1421
1422 The same rules have been implented on other platforms with case-
1423 insensitive but case-preserving filesystems too (including Cygwin, and
1424 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001425
Tim Peters25a9ce32001-02-19 07:06:36 +00001426- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1427 what it's supposed to do (and does do under NT and 2000) via direct
1428 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001429 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001430 all Win9x systems before.
1431
Tim Peters1eff7962001-03-01 02:31:33 +00001432- Build: Subproject _test (effectively) renamed to _testcapi.
1433
Tim Peters2fe289a2001-03-01 22:19:38 +00001434New platforms
1435
1436- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1437 Thanks to Steven Majewski!
1438
1439- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1440 Tishler!
1441
Guido van Rossum9089b272001-03-02 06:49:50 +00001442- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1443 Schwertberger! See RISCOS/README for more information -- it seems
1444 that because of the bizarre filename conventions on RISCOS, no port
1445 to that platform is easy. Note that the new variable os.endsep is
1446 silently supported in order to make life easier on this platform,
1447 but we don't advertise it because it's not worth for most folks to
1448 care about RISCOS portability.
1449
Tim Peters25a9ce32001-02-19 07:06:36 +00001450
Tim Petersd7b5e882001-01-25 03:36:26 +00001451What's New in Python 2.1 alpha 2?
1452=================================
Tim Peters40ead762001-01-27 05:35:26 +00001453
Tim Petersd7b5e882001-01-25 03:36:26 +00001454Core language, builtins, and interpreter
1455
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001456- Scopes nest. If a name is used in a function or class, but is not
1457 local, the definition in the nearest enclosing function scope will
1458 be used. One consequence of this change is that lambda statements
1459 could reference variables in the namespaces where the lambda is
1460 defined. In some unusual cases, this change will break code.
1461
1462 In all previous version of Python, names were resolved in exactly
1463 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001464 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001465 function A is defined within a function B, the names bound in B are
1466 not visible in A. The new rules make names bound in B visible in A,
1467 unless A contains a name binding that hides the binding in B.
1468
1469 Section 4.1 of the reference manual describes the new scoping rules
1470 in detail. The test script in Lib/test/test_scope.py demonstrates
1471 some of the effects of the change.
1472
1473 The new rules will cause existing code to break if it defines nested
1474 functions where an outer function has local variables with the same
1475 name as globals or builtins used by the inner function. Example:
1476
1477 def munge(str):
1478 def helper(x):
1479 return str(x)
1480 if type(str) != type(''):
1481 str = helper(str)
1482 return str.strip()
1483
1484 Under the old rules, the name str in helper() is bound to the
1485 builtin function str(). Under the new rules, it will be bound to
1486 the argument named str and an error will occur when helper() is
1487 called.
1488
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001489- The compiler will report a SyntaxError if "from ... import *" occurs
1490 in a function or class scope. The language reference has documented
1491 that this case is illegal, but the compiler never checked for it.
1492 The recent introduction of nested scope makes the meaning of this
1493 form of name binding ambiguous. In a future release, the compiler
1494 may allow this form when there is no possibility of ambiguity.
1495
Tim Peters40ead762001-01-27 05:35:26 +00001496- repr(string) is easier to read, now using hex escapes instead of octal,
1497 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1498
1499 >>> "\texample \r\n" + chr(0) + chr(255)
1500 '\texample \r\n\x00\xff' # in 2.1
1501 '\011example \015\012\000\377' # in 2.0
1502
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001503- Functions are now compared and hashed by identity, not by value, since
1504 the func_code attribute is writable.
1505
Fred Drakefb9d7122001-02-01 20:00:40 +00001506- Weak references (PEP 205) have been added. This involves a few
1507 changes in the core, an extension module (_weakref), and a Python
1508 module (weakref). The weakref module is the public interface. It
1509 includes support for "explicit" weak references, proxy objects, and
1510 mappings with weakly held values.
1511
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001512- A 'continue' statement can now appear in a try block within the body
1513 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001514 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001515
Tim Petersd7b5e882001-01-25 03:36:26 +00001516Standard library
1517
Barry Warsaw30dbd142001-01-31 22:14:01 +00001518- mailbox.py now has a new class, PortableUnixMailbox which is
1519 identical to UnixMailbox but uses a more portable scheme for
1520 determining From_ separators. Also, the constructors for all the
1521 classes in this module have a new optional `factory' argument, which
1522 is a callable used when new message classes must be instantiated by
1523 the next() method.
1524
Tim Petersd7b5e882001-01-25 03:36:26 +00001525- random.py is now self-contained, and offers all the functionality of
1526 the now-deprecated whrandom.py. See the docs for details. random.py
1527 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001528 and restoring the internal state of the generator; and jumpahead(n),
1529 for quickly forcing the internal state to be the same as if n calls to
1530 random() had been made. The latter is particularly useful for multi-
1531 threaded programs, creating one instance of the random.Random() class for
1532 each thread, then using .jumpahead() to force each instance to use a
1533 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001534
Tim Peters0de88fc2001-02-01 04:59:18 +00001535- random.py's seed() function is new. For bit-for-bit compatibility with
1536 prior releases, use the whseed function instead. The new seed function
1537 addresses two problems: (1) The old function couldn't produce more than
1538 about 2**24 distinct internal states; the new one about 2**45 (the best
1539 that can be done in the Wichmann-Hill generator). (2) The old function
1540 sometimes produced identical internal states when passed distinct
1541 integers, and there was no simple way to predict when that would happen;
1542 the new one guarantees to produce distinct internal states for all
1543 arguments in [0, 27814431486576L).
1544
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001545- The socket module now supports raw packets on Linux. The socket
1546 family is AF_PACKET.
1547
Tim Peters9ea17ac2001-02-02 05:57:15 +00001548- test_capi.py is a start at running tests of the Python C API. The tests
1549 are implemented by the new Modules/_testmodule.c.
1550
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001551- A new extension module, _symtable, provides provisional access to the
1552 internal symbol table used by the Python compiler. A higher-level
1553 interface will be added on top of _symtable in a future release.
1554
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001555- Removed the obsolete soundex module.
1556
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001557- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1558 the isSameNode method; NamedNodeMap the get method.
1559
1560- xml.sax.expatreader supports the lexical handler property; it
1561 generates comment, startCDATA, and endCDATA events.
1562
Tim Petersee826f82001-01-31 19:39:44 +00001563Windows changes
1564
1565- Build procedure: the zlib project is built in a different way that
1566 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001567 the zlib binary used. See PCbuild\readme.txt for details. Your old
1568 zlib-related directories can be deleted; you'll need to download fresh
1569 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001570
Tim Peters9ea17ac2001-02-02 05:57:15 +00001571- Build: New subproject _test for the benefit of test_capi.py (see above).
1572
Tim Petersb16c56f2001-02-02 21:24:51 +00001573- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1574 interface to some Python compiler internals).
1575
1576- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001577 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001578
Tim Petersa3a3a032000-11-30 05:22:44 +00001579What's New in Python 2.1 alpha 1?
1580=================================
1581
1582Core language, builtins, and interpreter
1583
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001584- There is a new Unicode companion to the PyObject_Str() API
1585 called PyObject_Unicode(). It behaves in the same way as the
1586 former, but assures that the returned value is an Unicode object
1587 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001588
Guido van Rossumf98eda02001-01-17 15:54:45 +00001589- The comparison operators support "rich comparison overloading" (PEP
1590 207). C extension types can provide a rich comparison function in
1591 the new tp_richcompare slot in the type object. The cmp() function
1592 and the C function PyObject_Compare() first try the new rich
1593 comparison operators before trying the old 3-way comparison. There
1594 is also a new C API PyObject_RichCompare() (which also falls back on
1595 the old 3-way comparison, but does not constrain the outcome of the
1596 rich comparison to a Boolean result).
1597
1598 The rich comparison function takes two objects (at least one of
1599 which is guaranteed to have the type that provided the function) and
1600 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1601 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1602 object, which may be NotImplemented (in which case the tp_compare
1603 slot function is used as a fallback, if defined).
1604
1605 Classes can overload individual comparison operators by defining one
1606 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001607 __ge__. There are no explicit "reflected argument" versions of
1608 these; instead, __lt__ and __gt__ are each other's reflection,
1609 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1610 reflection (similar at the C level). No other implications are
1611 made; in particular, Python does not assume that == is the Boolean
1612 inverse of !=, or that < is the Boolean inverse of >=. This makes
1613 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001614
1615 Classes or types that want to implement (in)equality tests but not
1616 the ordering operators (i.e. unordered types) should implement ==
1617 and !=, and raise an error for the ordering operators.
1618
Guido van Rossuma88479f2001-01-18 14:28:08 +00001619 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001620 Boolean; e.g. a matrix type might want to return a matrix of bits
1621 for A < B, giving elementwise comparisons. Such types should ensure
1622 that any interpretation of their value in a Boolean context raises
1623 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1624 at the C level) to always raise an exception.
1625
Guido van Rossuma88479f2001-01-18 14:28:08 +00001626- Complex numbers use rich comparisons to define == and != but raise
1627 an exception for <, <=, > and >=. Unfortunately, this also means
1628 that cmp() of two complex numbers raises an exception when the two
1629 numbers differ. Since it is not mathematically meaningful to compare
1630 complex numbers except for equality, I hope that this doesn't break
1631 too much code.
1632
Tim Peters3389f192001-02-18 08:48:49 +00001633- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001634 not defined by the language, other than that it's arbitrary but
1635 consistent (see the Reference Manual). An implementation detail changed
1636 in 2.1a1 such that None now compares less than any other object. Code
1637 relying on this new behavior (like code that relied on the previous
1638 behavior) does so at its own risk.
1639
Barry Warsaw573b5412001-01-15 20:43:18 +00001640- Functions and methods now support getting and setting arbitrarily
1641 named attributes (PEP 232). Functions have a new __dict__
1642 (a.k.a. func_dict) which hold the function attributes. Methods get
1643 and set attributes on their underlying im_func. It is a TypeError
1644 to set an attribute on a bound method.
1645
Guido van Rossum051e3352001-01-15 19:11:10 +00001646- The xrange() object implementation has been improved so that
1647 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1648 limitation that in this case len(xrange(sys.maxint)) can't be
1649 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1650 work fine as long as the index i doesn't actually reach 2**31.
1651 (Python uses regular ints for sequence and string indices; fixing
1652 that is much more work.)
1653
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001654- Two changes to from...import:
1655
Guido van Rossumba381232001-02-03 15:06:40 +00001656 1) "from M import X" now works even if (after loading module M)
1657 sys.modules['M'] is not a real module; it's basically a getattr()
1658 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001659
1660 2) "from M import *" now looks for M.__all__ to decide which names to
1661 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1662 filters out names starting with '_' as before. Whether or not
1663 __all__ exists, there's no restriction on the type of M.
1664
Guido van Rossumf61f1662001-01-10 20:13:55 +00001665- File objects have a new method, xreadlines(). This is the fastest
1666 way to iterate over all lines in a file:
1667
1668 for line in file.xreadlines():
1669 ...do something to line...
1670
1671 See the xreadlines module (mentioned below) for how to do this for
1672 other file-like objects.
1673
1674- Even if you don't use file.xreadlines(), you may expect a speedup on
1675 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001676 quite a bit in platform-specific ways: on systems (like Linux) that
1677 support flockfile(), getc_unlocked(), and funlockfile(), those are
1678 used by default. On systems (like Windows) without getc_unlocked(),
1679 a complicated (but still thread-safe) method using fgets() is used by
1680 default.
1681
Tim Petersd52269b2001-01-25 06:23:18 +00001682 You can force use of the fgets() method by #define'ing
1683 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001684 getc_unlocked()).
1685
Tim Petersd52269b2001-01-25 06:23:18 +00001686 You can force fgets() not to be used by #define'ing
1687 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001688 test_bufio.py fails -- and let us know if it does!).
1689
1690- In addition, the fileinput module, while still slower than the other
1691 methods on most platforms, has been sped up too, by using
1692 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001693
1694- Support for run-time warnings has been added, including a new
1695 command line option (-W) to specify the disposition of warnings.
1696 See the description of the warnings module below.
1697
1698- Extensive changes have been made to the coercion code. This mostly
1699 affects extension modules (which can now implement mixed-type
1700 numerical operators without having to use coercion), but
1701 occasionally, in boundary cases the coercion semantics have changed
1702 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001703 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001704 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001705 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001706
Guido van Rossumf98eda02001-01-17 15:54:45 +00001707- In connection with the coercion changes, a new built-in singleton
1708 object, NotImplemented is defined. This can be returned for
1709 operations that wish to indicate they are not implemented for a
1710 particular combination of arguments. From C, this is
1711 Py_NotImplemented.
1712
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001713- The interpreter accepts now bytecode files on the command line even
1714 if they do not have a .pyc or .pyo extension. On Linux, after executing
1715
Martin v. Löwise214baa2001-02-04 22:37:56 +00001716import imp,sys,string
1717magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1718reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1719open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001720
1721 any byte code file can be used as an executable (i.e. as an argument
1722 to execve(2)).
1723
Tim Peters9940b802000-12-01 07:59:35 +00001724- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001725 character. In 1.6 and earlier, they never produced a sign,
1726 and raised an error if the value of the long was too large
1727 to fit in a Python int. In 2.0, they produced a sign if and
1728 only if too large to fit in an int. This was inconsistent
1729 across platforms (because the size of an int varies across
1730 platforms), and inconsistent with hex() and oct(). Example:
1731
1732 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001733 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001734 'ffffffbe' # in 2.0 and before, on 32-bit machines
1735 >>> hex(-0x42L)
1736 '-0x42L' # in all versions of Python
1737
Tim Peters9940b802000-12-01 07:59:35 +00001738 The behavior of %d formats for negative Python longs remains
1739 the same as in 2.0 (although in 1.6 and before, they raised
1740 an error if the long didn't fit in a Python int).
1741
1742 %u formats don't make sense for Python longs, but are allowed
1743 and treated the same as %d in 2.1. In 2.0, a negative long
1744 formatted via %u produced a sign if and only if too large to
1745 fit in an int. In 1.6 and earlier, a negative long formatted
1746 via %u raised an error if it was too big to fit in an int.
1747
Guido van Rossum3661d392000-12-12 22:10:31 +00001748- Dictionary objects have an odd new method, popitem(). This removes
1749 an arbitrary item from the dictionary and returns it (in the form of
1750 a (key, value) pair). This can be useful for algorithms that use a
1751 dictionary as a bag of "to do" items and repeatedly need to pick one
1752 item. Such algorithms normally end up running in quadratic time;
1753 using popitem() they can usually be made to run in linear time.
1754
Tim Peters36cdad12000-12-29 02:06:45 +00001755Standard library
1756
Thomas Woutersfe385252001-01-19 23:16:56 +00001757- In the time module, the time argument to the functions strftime,
1758 localtime, gmtime, asctime and ctime is now optional, defaulting to
1759 the current time (in the local timezone).
1760
Guido van Rossumda91f222001-01-15 16:36:08 +00001761- The ftplib module now defaults to passive mode, which is deemed a
1762 more useful default given that clients are often inside firewalls
1763 these days. Note that this could break if ftplib is used to connect
1764 to a *server* that is inside a firewall, from outside; this is
1765 expected to be a very rare situation. To fix that, you can call
1766 ftp.set_pasv(0).
1767
Martin v. Löwis10a27872001-01-13 09:54:41 +00001768- The module site now treats .pth files not only for path configuration,
1769 but also supports extensions to the initialization code: Lines starting
1770 with import are executed.
1771
Guido van Rossumf61f1662001-01-10 20:13:55 +00001772- There's a new module, warnings, which implements a mechanism for
1773 issuing and filtering warnings. There are some new built-in
1774 exceptions that serve as warning categories, and a new command line
1775 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1776 turns warnings into errors). warnings.warn(message[, category])
1777 issues a warning message; this can also be called from C as
1778 PyErr_Warn(category, message).
1779
1780- A new module xreadlines was added. This exports a single factory
1781 function, xreadlines(). The intention is that this code is the
1782 absolutely fastest way to iterate over all lines in an open
1783 file(-like) object:
1784
1785 import xreadlines
1786 for line in xreadlines.xreadlines(file):
1787 ...do something to line...
1788
1789 This is equivalent to the previous the speed record holder using
1790 file.readlines(sizehint). Note that if file is a real file object
1791 (as opposed to a file-like object), this is equivalent:
1792
1793 for line in file.xreadlines():
1794 ...do something to line...
1795
Tim Peters36cdad12000-12-29 02:06:45 +00001796- The bisect module has new functions bisect_left, insort_left,
1797 bisect_right and insort_right. The old names bisect and insort
1798 are now aliases for bisect_right and insort_right. XXX_right
1799 and XXX_left methods differ in what happens when the new element
1800 compares equal to one or more elements already in the list: the
1801 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001802 right. Code that doesn't care where equal elements end up should
1803 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001804
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001805- The new curses.panel module wraps the panel library that forms part
1806 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1807
Guido van Rossumf61f1662001-01-10 20:13:55 +00001808- The SocketServer module now sets the allow_reuse_address flag by
1809 default in the TCPServer class.
1810
1811- A new function, sys._getframe(), returns the stack frame pointer of
1812 the caller. This is intended only as a building block for
1813 higher-level mechanisms such as string interpolation.
1814
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001815- The pyexpat module supports a number of new handlers, which are
1816 available only in expat 1.2. If invocation of a callback fails, it
1817 will report an additional frame in the traceback. Parser objects
1818 participate now in garbage collection. If expat reports an unknown
1819 encoding, pyexpat will try to use a Python codec; that works only
1820 for single-byte charsets. The parser type objects is exposed as
1821 XMLParserObject.
1822
1823- xml.dom now offers standard definitions for symbolic node type and
1824 exception code constants, and a hierarchy of DOM exceptions. minidom
1825 was adjusted to use them.
1826
1827- The conformance of xml.dom.minidom to the DOM specification was
1828 improved. It detects a number of additional error cases; the
1829 previous/next relationship works even when the tree is modified;
1830 Node supports the normalize() method; NamedNodeMap, DocumentType and
1831 DOMImplementation classes were added; Element supports the
1832 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1833 method.
1834
Guido van Rossumf61f1662001-01-10 20:13:55 +00001835Build issues
1836
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001837- For Unix (and Unix-compatible) builds, configuration and building of
1838 extension modules is now greatly automated. Rather than having to
1839 edit the Modules/Setup file to indicate which modules should be
1840 built and where their include files and libraries are, a
1841 distutils-based setup.py script now takes care of building most
1842 extension modules. All extension modules built this way are built
1843 as shared libraries. Only a few modules that must be linked
1844 statically are still listed in the Setup file; you won't need to
1845 edit their configuration.
1846
1847- Python should now build out of the box on Cygwin. If it doesn't,
1848 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001849
1850- Python now always uses its own (renamed) implementation of getopt()
1851 -- there's too much variation among C library getopt()
1852 implementations.
1853
1854- C++ compilers are better supported; the CXX macro is always set to a
1855 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001856
Tim Petersd92dfe02000-12-12 01:18:41 +00001857Windows changes
1858
1859- select module: By default under Windows, a select() call
1860 can specify no more than 64 sockets. Python now boosts
1861 this Microsoft default to 512. If you need even more than
1862 that, see the MS docs (you'll need to #define FD_SETSIZE
1863 and recompile Python from source).
1864
Guido van Rossumf61f1662001-01-10 20:13:55 +00001865- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1866 subdirectory is no more!
1867
Tim Petersa3a3a032000-11-30 05:22:44 +00001868
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001869What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001870=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001871
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001872Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001873changes are in the file HISTORY. If you are making the jump directly
1874from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1875HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001876
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001877Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1878the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1879http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001880
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001881--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001882
1883======================================================================
1884
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001885What's new in 2.0 (since release candidate 1)?
1886==============================================
1887
1888Standard library
1889
1890- The copy_reg module was modified to clarify its intended use: to
1891 register pickle support for extension types, not for classes.
1892 pickle() will raise a TypeError if it is passed a class.
1893
1894- Fixed a bug in gettext's "normalize and expand" code that prevented
1895 it from finding an existing .mo file.
1896
1897- Restored support for HTTP/0.9 servers in httplib.
1898
Tim Peters989b7b92000-10-16 20:24:53 +00001899- The math module was changed to stop raising OverflowError in case of
1900 underflow, and return 0 instead in underflow cases. Whether Python
1901 used to raise OverflowError in case of underflow was platform-
1902 dependent (it did when the platform math library set errno to ERANGE
1903 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001904
1905- Fixed a bug in StringIO that occurred when the file position was not
1906 at the end of the file and write() was called with enough data to
1907 extend past the end of the file.
1908
1909- Fixed a bug that caused Tkinter error messages to get lost on
1910 Windows. The bug was fixed by replacing direct use of
1911 interp->result with Tcl_GetStringResult(interp).
1912
1913- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1914 redirect response.
1915
1916- Several changes were made to distutils: Some debugging code was
1917 removed from util. Fixed the installer used when an external zip
1918 program (like WinZip) is not found; the source code for this
1919 installer is in Misc/distutils. check_lib() was modified to behave
1920 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1921 test for whether installed modules are on sys.path was changed to
1922 use both normcase() and normpath().
1923
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001924- Several minor bugs were fixed in the xml package (the minidom,
1925 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001926
1927- The regression test driver (regrtest.py) behavior when invoked with
1928 -l changed: It now reports a count of objects that are recognized as
1929 garbage but not freed by the garbage collector.
1930
Tim Peters989b7b92000-10-16 20:24:53 +00001931- The regression test for the math module was changed to test
1932 exceptional behavior when the test is run in verbose mode. Python
1933 cannot yet guarantee consistent exception behavior across platforms,
1934 so the exception part of test_math is run only in verbose mode, and
1935 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001936
1937Internals
1938
1939- PyOS_CheckStack() has been disabled on Win64, where it caused
1940 test_sre to fail.
1941
1942Build issues
1943
1944- Changed compiler flags, so that gcc is always invoked with -Wall and
1945 -Wstrict-prototypes. Users compiling Python with GCC should see
1946 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001947 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001948 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001949
Tim Petersa3a3a032000-11-30 05:22:44 +00001950- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001951
1952Tools and other miscellany
1953
1954- The compiler in Tools/compiler was updated to support the new
1955 language features introduced in 2.0: extended print statement, list
1956 comprehensions, and augmented assignments. The new compiler should
1957 also be backwards compatible with Python 1.5.2; the compiler will
1958 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001959 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001960
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001961What's new in 2.0 release candidate 1 (since beta 2)?
1962=====================================================
1963
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001964What is release candidate 1?
1965
1966We believe that release candidate 1 will fix all known bugs that we
1967intend to fix for the 2.0 final release. This release should be a bit
1968more stable than the previous betas. We would like to see even more
1969widespread testing before the final release, so we are producing this
1970release candidate. The final release will be exactly the same unless
1971any show-stopping (or brown bag) bugs are found by testers of the
1972release candidate.
1973
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001974All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001975to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001976
1977Core language, builtins, and interpreter
1978
1979- A bug that caused crashes when __coerce__ was used with augmented
1980 assignment, e.g. +=, was fixed.
1981
1982- Raise ZeroDivisionError when raising zero to a negative number,
1983 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1984 power operator and the result of math.pow(0.0, -2.0) will vary by
1985 platform. On Linux, it raises a ValueError.
1986
1987- A bug in Unicode string interpolation was fixed that occasionally
1988 caused errors with formats including "%%". For example, the
1989 following expression "%% %s" % u"abc" no longer raises a TypeError.
1990
1991- Compilation of deeply nested expressions raises MemoryError instead
1992 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1993
1994- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1995 rendering them useless. They are now written in binary mode again.
1996
1997Standard library
1998
1999- Keyword arguments are now accepted for most pattern and match object
2000 methods in SRE, the standard regular expression engine.
2001
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002002- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002003 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002004
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002005- Several bugs in the Unicode handling and error handling in _tkinter
2006 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002007
2008- Fix memory management errors in Merge() and Tkapp_Call() routines.
2009
2010- Several changes were made to cStringIO to make it compatible with
2011 the file-like object interface and with StringIO. If operations are
2012 performed on a closed object, an exception is raised. The truncate
2013 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002014 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002015
2016- There were many changes made to the linuxaudiodev module and its
2017 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002018 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002019
2020 Note that this module is named poorly, because it should work
2021 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002022 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002023
2024 The module now raises exceptions when errors occur instead of
2025 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2026 audio) and defines a getptr() method that calls the
2027 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2028
2029- The library_version attribute, introduced in an earlier beta, was
2030 removed because it can not be supported with early versions of the C
2031 readline library, which provides no way to determine the version at
2032 compile-time.
2033
2034- The binascii module is now enabled on Win64.
2035
Tim Peters46446d62000-10-09 21:19:31 +00002036- tokenize.py no longer suffers "recursion depth" errors when parsing
2037 programs with very long string literals.
2038
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002039Internals
2040
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002041- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002042 which is called when the interpreter starts up to determine where
2043 the standard library is installed. These vulnerabilities affect all
2044 previous versions of Python and can be exploited by setting very
2045 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2046 setuid Python script, although use of the wrapper in
2047 Misc/setuid-prog.c will eliminate the vulnerability.
2048
2049- Fixed garbage collection bugs in instance creation that were
2050 triggered when errors occurred during initialization. The solution,
2051 applied in cPickle and in PyInstance_New(), is to call
2052 PyObject_GC_Init() after the initialization of the object's
2053 container attributes is complete.
2054
2055- pyexpat adds definitions of PyModule_AddStringConstant and
2056 PyModule_AddObject if the Python version is less than 2.0, which
2057 provides compatibility with PyXML on Python 1.5.2.
2058
2059- If the platform has a bogus definition for LONG_BIT (the number of
2060 bits in a long), an error will be reported at compile time.
2061
2062- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2063 collection crashes and possibly other, unreported crashes.
2064
2065- Fixed a memory leak in _PyUnicode_Fini().
2066
2067Build issues
2068
2069- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002070 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002071 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002072
2073- The mmap.PAGESIZE constant is now initialized using sysconf when
2074 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2075
2076- The md5 file should now compile on all platforms.
2077
2078- The select module now compiles on platforms that do not define
2079 POLLRDNORM and related constants.
2080
2081- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002082 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002083
Jeremy Hylton10921202000-10-09 18:34:12 +00002084- BeOS: A number of changes were made to the build and installation
2085 process. ar-fake now operates on a directory of object files.
2086 dl_export.h is gone, and its macros now appear on the mwcc command
2087 line during build on PPC BeOS.
2088
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002089- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002090 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002091
2092- Cygwin: Support for shared libraries, Tkinter, and sockets.
2093
2094- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2095
2096Tools and other miscellany
2097
2098- Removed debugging prints from main used with freeze.
2099
Tim Peters46446d62000-10-09 21:19:31 +00002100- IDLE auto-indent no longer crashes when it encounters Unicode
2101 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002102
2103What's new in 2.0 beta 2 (since beta 1)?
2104========================================
2105
2106Core language, builtins, and interpreter
2107
Tim Peters482c0212000-09-26 06:33:09 +00002108- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002109 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002110
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002111- Add -h and -V command line options to print the usage message and
2112 Python version number and exit immediately.
2113
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002114- eval() and exec accept Unicode objects as code parameters.
2115
2116- getattr() and setattr() now also accept Unicode objects for the
2117 attribute name, which are converted to strings using the default
2118 encoding before lookup.
2119
2120- Multiplication on string and Unicode now does proper bounds
2121 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2122 string is too long."
2123
2124- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002125 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002126
Jeremy Hylton1b618592000-09-26 05:32:36 +00002127
2128Standard library and extensions
2129
Guido van Rossum5b08f132001-04-16 02:05:23 +00002130- socket module: the OpenSSL code now adds support for RAND_status()
2131 and EGD (Entropy Gathering Device).
2132
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002133- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002134 argument checking; it still takes no arguments.
2135
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002136- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002137
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002138- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002139
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002140- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002141
2142- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002143 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002144
2145- copy: Copy Unicode objects atomically.
2146
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002147- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002148
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002149- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002150
Fred Drake67233bc2000-09-26 16:40:27 +00002151- dbm: Add get() and setdefault() methods to dbm object. Add constant
2152 `library' to module that names the library used. Added doc strings
2153 and method names to error messages. Uses configure to determine
2154 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2155 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002156
2157- distutils: Update to version 0.9.3.
2158
2159- dl: Add several dl.RTLD_ constants.
2160
2161- fpectl: Now supported on FreeBSD.
2162
2163- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2164 found by the collector will be saved in gc.garbage. This is useful
2165 for debugging a program that creates reference cycles.
2166
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002167- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002168 of HTTP class. Do not close socket on zero-length response. Do not
2169 crash when server sends invalid content-length header.
2170
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002171- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002172
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002173- marshal: When reading a short, sign-extend on platforms where shorts
2174 are bigger than 16 bits. When reading a long, repair the unportable
2175 sign extension that was being done for 64-bit machines. (It assumed
2176 that signed right shift sign-extends.)
2177
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002178- operator: Add contains(), invert(), __invert__() as aliases for
2179 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002180
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002181- os: Add support for popen2() and popen3() on all platforms where
2182 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002183
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002184- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002185 clicking on a file in Explorer (or passing the file name to the
2186 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002187
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002188- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002189 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002190
2191- pickle: Now raises ValueError when an invalid pickle that contains
2192 a non-string repr where a string repr was expected. This behavior
2193 matches cPickle.
2194
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002195- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002196
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002197- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002198
2199- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002200 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002201 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002202
2203- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002204 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002205
2206- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002207 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002208 few cycles during startup since the first call to
2209 setdefaultencoding() will initialize the codec registry and the
2210 encodings package.
2211
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002212- socket: Support for size hint in readlines() method of object returned
2213 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002214
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002215- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002216 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002217 is followed by whitespace.
2218
Tim Petersa3a3a032000-11-30 05:22:44 +00002219- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002220
2221- struct: Check ranges for bytes and shorts.
2222
2223- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002224 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002225
2226- Tkinter: Image objects are now guaranteed to have unique ids. Set
2227 event.delta to zero if Tk version doesn't support mousewheel.
2228 Removed some debugging prints.
2229
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002230- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002231
Fred Drake67233bc2000-09-26 16:40:27 +00002232- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002233 which works around a bug in Norton AntiVirus 2000 that leads directly
2234 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002235
2236- xml: New version detection code allows PyXML to override standard
2237 XML package if PyXML version is greater than 0.6.1.
2238
Fred Drake64bb3802000-09-26 16:21:35 +00002239- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2240 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2241 tree only for nodes which are sufficiently interesting to a specific
2242 application. Does not provide the HTML-specific extensions. Still
2243 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002244
Fred Drake64bb3802000-09-26 16:21:35 +00002245- xml.sax: SAX 2 support for Python, including all the handler
2246 interfaces needed to process XML 1.0 compliant XML. Some
2247 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002248
Fred Drake64bb3802000-09-26 16:21:35 +00002249- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2250 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002251
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002252
Jeremy Hylton1b618592000-09-26 05:32:36 +00002253C API
2254
2255- Add three new convenience functions for module initialization --
2256 PyModule_AddObject(), PyModule_AddIntConstant(), and
2257 PyModule_AddStringConstant().
2258
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002259- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002260 removed and add #error to Python.h if NULL isn't defined after
2261 #include of stdio.h.
2262
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002263- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002264 backwards compatibility (at the source level) with old extensions.
2265
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002266- A wrapper API was added for signal() and sigaction(). Instead of
2267 either function, always use PyOS_getsig() to get a signal handler
2268 and PyOS_setsig() to set one. A new convenience typedef
2269 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002270
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002271- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002272 internal data buffer and size of a string object -- or the default
2273 encoded version of a Unicode object.
2274
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002275- PyString_Size() and PyString_AsString() accept Unicode objects.
2276
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002277- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002278 exists). INT_MAX and LONG_MAX will always be defined, even if
2279 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002280
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002281- PyFloat_FromString takes a second argument, pend, that was
2282 effectively useless. It is now officially useless but preserved for
2283 backwards compatibility. If the pend argument is not NULL, *pend is
2284 set to NULL.
2285
2286- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2287 for the attribute name. See note on getattr() above.
2288
2289- A few bug fixes to argument processing for Unicode.
2290 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2291 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2292 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002293 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002294
2295- Py_BuildValue accepts B format (for bgen-generated code).
2296
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002297
Jeremy Hylton1b618592000-09-26 05:32:36 +00002298Internals
2299
2300- On Unix, fix code for finding Python installation directory so that
2301 it works when argv[0] is a relative path.
2302
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002303- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002304 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002305 rather than by generating a copy of the object.
2306
Tim Peters482c0212000-09-26 06:33:09 +00002307- Several of the internal Unicode tables are much smaller now, and
2308 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002309
Jeremy Hylton97693b02000-09-26 17:42:51 +00002310- In the garbage collector: Fixed bug in collection of tuples. Fixed
2311 bug that caused some instances to be removed from the container set
2312 while they were still live. Fixed parsing in gc.set_debug() for
2313 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002314
2315- Fixed refcount problem in instance deallocation that only occurred
2316 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2317
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002318- On Windows, getpythonregpath is now protected against null data in
2319 registry key.
2320
2321- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002322 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002323
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002324
Jeremy Hylton1b618592000-09-26 05:32:36 +00002325Build and platform-specific issues
2326
2327- Better support of GNU Pth via --with-pth configure option.
2328
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002329- Python/C API now properly exposed to dynamically-loaded extension
2330 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002331
2332- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2333 Don't define MS_SYNC to be zero when it is undefined. Added missing
2334 prototypes in posixmodule.c.
2335
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002336- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002337 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002338
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002339- Fix largefile support on older NetBSD systems and OpenBSD by adding
2340 define for TELL64.
2341
2342
2343Tools and other miscellany
2344
2345- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2346
2347- freeze: The modulefinder now works with 2.0 opcodes.
2348
Tim Petersa3a3a032000-11-30 05:22:44 +00002349- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002350 Move hackery of sys.argv until after the Tk instance has been
2351 created, which allows the application-specific Tkinter
2352 initialization to be executed if present; also pass an explicit
2353 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002354
Jeremy Hylton1b618592000-09-26 05:32:36 +00002355
2356What's new in 2.0 beta 1?
2357=========================
2358
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002359Source Incompatibilities
2360------------------------
2361
2362None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2363such as single-argument append(), connect() and bind(), and changes to
2364str(long) and repr(float).
2365
2366
2367Binary Incompatibilities
2368------------------------
2369
2370- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2371with Python 2.0; these extensions will have to be rebuilt for Python
23722.0.
2373
2374- On Windows, attempting to import a third party extension built for
2375Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2376can do about this. Check your PYTHONPATH environment variable!
2377
2378- Python bytecode files (*.pyc and *.pyo) are not compatible between
2379releases.
2380
2381
2382Overview of Changes Since 1.6
2383-----------------------------
2384
2385There are many new modules (including brand new XML support through
2386the xml package, and i18n support through the gettext module); a list
2387of all new modules is included below. Lots of bugs have been fixed.
2388
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002389The process for making major new changes to the language has changed
2390since Python 1.6. Enhancements must now be documented by a Python
2391Enhancement Proposal (PEP) before they can be accepted.
2392
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002393There are several important syntax enhancements, described in more
2394detail below:
2395
2396 - Augmented assignment, e.g. x += 1
2397
2398 - List comprehensions, e.g. [x**2 for x in range(10)]
2399
2400 - Extended import statement, e.g. import Module as Name
2401
2402 - Extended print statement, e.g. print >> file, "Hello"
2403
2404Other important changes:
2405
2406 - Optional collection of cyclical garbage
2407
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002408Python Enhancement Proposal (PEP)
2409---------------------------------
2410
2411PEP stands for Python Enhancement Proposal. A PEP is a design
2412document providing information to the Python community, or describing
2413a new feature for Python. The PEP should provide a concise technical
2414specification of the feature and a rationale for the feature.
2415
2416We intend PEPs to be the primary mechanisms for proposing new
2417features, for collecting community input on an issue, and for
2418documenting the design decisions that have gone into Python. The PEP
2419author is responsible for building consensus within the community and
2420documenting dissenting opinions.
2421
2422The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002423
2424Augmented Assignment
2425--------------------
2426
2427This must have been the most-requested feature of the past years!
2428Eleven new assignment operators were added:
2429
Guido van Rossume905e952000-09-05 12:42:46 +00002430 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002431
2432For example,
2433
2434 A += B
2435
2436is similar to
2437
2438 A = A + B
2439
2440except that A is evaluated only once (relevant when A is something
2441like dict[index].attr).
2442
2443However, if A is a mutable object, A may be modified in place. Thus,
2444if A is a number or a string, A += B has the same effect as A = A+B
2445(except A is only evaluated once); but if a is a list, A += B has the
2446same effect as A.extend(B)!
2447
2448Classes and built-in object types can override the new operators in
2449order to implement the in-place behavior; the not-in-place behavior is
2450used automatically as a fallback when an object doesn't implement the
2451in-place behavior. For classes, the method name is derived from the
2452method name for the corresponding not-in-place operator by inserting
2453an 'i' in front of the name, e.g. __iadd__ implements in-place
2454__add__.
2455
2456Augmented assignment was implemented by Thomas Wouters.
2457
2458
2459List Comprehensions
2460-------------------
2461
2462This is a flexible new notation for lists whose elements are computed
2463from another list (or lists). The simplest form is:
2464
2465 [<expression> for <variable> in <sequence>]
2466
Guido van Rossum56db0952000-09-06 23:34:25 +00002467For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002468This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002469
2470You can also add a condition:
2471
2472 [<expression> for <variable> in <sequence> if <condition>]
2473
2474For example, [w for w in words if w == w.lower()] would yield the list
2475of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002476than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002477
2478You can also have nested for loops and more than one 'if' clause. For
2479example, here's a function that flattens a sequence of sequences::
2480
2481 def flatten(seq):
2482 return [x for subseq in seq for x in subseq]
2483
2484 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2485
2486This prints
2487
2488 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2489
2490List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002491Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002492
2493
2494Extended Import Statement
2495-------------------------
2496
2497Many people have asked for a way to import a module under a different
2498name. This can be accomplished like this:
2499
2500 import foo
2501 bar = foo
2502 del foo
2503
2504but this common idiom gets old quickly. A simple extension of the
2505import statement now allows this to be written as follows:
2506
2507 import foo as bar
2508
2509There's also a variant for 'from ... import':
2510
2511 from foo import bar as spam
2512
2513This also works with packages; e.g. you can write this:
2514
2515 import test.regrtest as regrtest
2516
2517Note that 'as' is not a new keyword -- it is recognized only in this
2518context (this is only possible because the syntax for the import
2519statement doesn't involve expressions).
2520
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002521Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002522
2523
2524Extended Print Statement
2525------------------------
2526
2527Easily the most controversial new feature, this extension to the print
2528statement adds an option to make the output go to a different file
2529than the default sys.stdout.
2530
2531For example, to write an error message to sys.stderr, you can now
2532write:
2533
2534 print >> sys.stderr, "Error: bad dog!"
2535
2536As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002537evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002538
2539 print >> None, "Hello world"
2540
2541is equivalent to
2542
2543 print "Hello world"
2544
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002545Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002546
2547
2548Optional Collection of Cyclical Garbage
2549---------------------------------------
2550
2551Python is now equipped with a garbage collector that can hunt down
2552cyclical references between Python objects. It's no replacement for
2553reference counting; in fact, it depends on the reference counts being
2554correct, and decides that a set of objects belong to a cycle if all
2555their reference counts can be accounted for from their references to
2556each other. This devious scheme was first proposed by Eric Tiedemann,
2557and brought to implementation by Neil Schemenauer.
2558
2559There's a module "gc" that lets you control some parameters of the
2560garbage collection. There's also an option to the configure script
2561that lets you enable or disable the garbage collection. In 2.0b1,
2562it's on by default, so that we (hopefully) can collect decent user
2563experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002564performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002565off by default in the final 2.0 release.
2566
2567
2568Smaller Changes
2569---------------
2570
2571A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2572map(None, seq1, seq2, ...) when the sequences have the same length;
2573i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2574the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002575zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002576
2577sys.version_info is a tuple (major, minor, micro, level, serial).
2578
2579Dictionaries have an odd new method, setdefault(key, default).
2580dict.setdefault(key, default) returns dict[key] if it exists; if not,
2581it sets dict[key] to default and returns that value. Thus:
2582
2583 dict.setdefault(key, []).append(item)
2584
2585does the same work as this common idiom:
2586
2587 if not dict.has_key(key):
2588 dict[key] = []
2589 dict[key].append(item)
2590
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002591There are two new variants of SyntaxError that are raised for
2592indentation-related errors: IndentationError and TabError.
2593
2594Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2595escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002596
2597The limits on the size of expressions and file in Python source code
2598have been raised from 2**16 to 2**32. Previous versions of Python
2599were limited because the maximum argument size the Python VM accepted
2600was 2**16. This limited the size of object constructor expressions,
2601e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2602limit was raised thanks to a patch by Charles Waldman that effectively
2603fixes the problem. It is now much more likely that you will be
2604limited by available memory than by an arbitrary limit in Python.
2605
2606The interpreter's maximum recursion depth can be modified by Python
2607programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2608limit is the maximum number of recursive calls that can be made by
2609Python code. The limit exists to prevent infinite recursion from
2610overflowing the C stack and causing a core dump. The default value is
26111000. The maximum safe value for a particular platform can be found
2612by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002613
2614New Modules and Packages
2615------------------------
2616
2617atexit - for registering functions to be called when Python exits.
2618
2619imputil - Greg Stein's alternative API for writing custom import
2620hooks.
2621
2622pyexpat - an interface to the Expat XML parser, contributed by Paul
2623Prescod.
2624
2625xml - a new package with XML support code organized (so far) in three
2626subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2627would fill a volume. There's a special feature whereby a
2628user-installed package named _xmlplus overrides the standard
2629xmlpackage; this is intended to give the XML SIG a hook to distribute
2630backwards-compatible updates to the standard xml package.
2631
2632webbrowser - a platform-independent API to launch a web browser.
2633
2634
Guido van Rossume905e952000-09-05 12:42:46 +00002635Changed Modules
2636---------------
2637
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002638array -- new methods for array objects: count, extend, index, pop, and
2639remove
2640
2641binascii -- new functions b2a_hex and a2b_hex that convert between
2642binary data and its hex representation
2643
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002644calendar -- Many new functions that support features including control
2645over which day of the week is the first day, returning strings instead
2646of printing them. Also new symbolic constants for days of week,
2647e.g. MONDAY, ..., SUNDAY.
2648
2649cgi -- FieldStorage objects have a getvalue method that works like a
2650dictionary's get method and returns the value attribute of the object.
2651
2652ConfigParser -- The parser object has new methods has_option,
2653remove_section, remove_option, set, and write. They allow the module
2654to be used for writing config files as well as reading them.
2655
2656ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002657optionally support the RFC 959 REST command.
2658
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002659gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002660
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002661httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2662the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002663
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002664locale -- implement getdefaultlocale for Win32 and Macintosh
2665
2666marshal -- no longer dumps core when marshaling deeply nested or
2667recursive data structures
2668
2669os -- new functions isatty, seteuid, setegid, setreuid, setregid
2670
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002671os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2672support under Unix.
2673
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002674os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002675
2676os.path -- fix semantics of os.path.commonprefix
2677
2678smtplib -- support for sending very long messages
2679
2680socket -- new function getfqdn()
2681
2682readline -- new functions to read, write and truncate history files.
2683The readline section of the library reference manual contains an
2684example.
2685
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002686select -- add interface to poll system call
2687
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002688shutil -- new copyfileobj function
2689
2690SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2691HTTP server.
2692
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002693Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002694
2695urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002696e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002697
2698whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002699
2700
2701Obsolete Modules
2702----------------
2703
2704None. However note that 1.6 made a whole slew of modules obsolete:
2705stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2706poly, zmod, strop, util, whatsound.
2707
2708
2709Changed, New, Obsolete Tools
2710----------------------------
2711
Tim Peters8b092332000-09-05 20:15:25 +00002712None.
Guido van Rossume905e952000-09-05 12:42:46 +00002713
2714
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002715C-level Changes
2716---------------
2717
2718Several cleanup jobs were carried out throughout the source code.
2719
2720All C code was converted to ANSI C; we got rid of all uses of the
2721Py_PROTO() macro, which makes the header files a lot more readable.
2722
2723Most of the portability hacks were moved to a new header file,
2724pyport.h; several other new header files were added and some old
2725header files were removed, in an attempt to create a more rational set
2726of header files. (Few of these ever need to be included explicitly;
2727they are all included by Python.h.)
2728
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002729Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002730and Win64, especially for the new Intel Itanium processor. Mick also
2731added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002732
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002733The C APIs to return an object's size have been update to consistently
2734use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2735previous versions, the abstract interfaces used PyXXX_Length and the
2736concrete interfaces used PyXXX_Size. The old names,
2737e.g. PyObject_Length, are still available for backwards compatibility
2738at the API level, but are deprecated.
2739
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002740The PyOS_CheckStack function has been implemented on Windows by
2741Fredrik Lundh. It prevents Python from failing with a stack overflow
2742on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002743
2744The GC changes resulted in creation of two new slots on object,
2745tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002746the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002747
2748The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002749C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002750
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002751PyErr_Format has been updated to automatically calculate the size of
2752the buffer needed to hold the formatted result string. This change
2753prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002754
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002755New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002756
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002757PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2758that are the same as their non-Ex counterparts except they take an
2759extra flag argument that tells them to close the file when done.
2760
2761XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002762
Tim Peters8b092332000-09-05 20:15:25 +00002763
2764Windows Changes
2765---------------
2766
2767New popen2/popen3/peopen4 in os module (see Changed Modules above).
2768
2769os.popen is much more usable on Windows 95 and 98. See Microsoft
2770Knowledge Base article Q150956. The Win9x workaround described there
2771is implemented by the new w9xpopen.exe helper in the root of your
2772Python installation. Note that Python uses this internally; it is not
2773a standalone program.
2774
2775Administrator privileges are no longer required to install Python
2776on Windows NT or Windows 2000. If you have administrator privileges,
2777Python's registry info will be written under HKEY_LOCAL_MACHINE.
2778Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002779under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002780uses of Python, but will prevent some advanced uses from working
2781(for example, running a Python script as an NT service, or possibly
2782from CGI).
2783
2784[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2785installer; instead, it installs the needed Tcl/Tk files directly in the
2786Python directory. If you already have a Tcl/Tk installation, this
2787wastes some disk space (about 4 Megs) but avoids problems with
2788conflicting Tcl/Tk installations, and makes it much easier for Python
2789to ensure that Tcl/Tk can find all its files.
2790
2791[This was new in 1.6] The Windows installer now installs by default in
2792\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2793
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002794
2795Updates to the changes between 1.5.2 and 1.6
2796--------------------------------------------
2797
2798The 1.6 NEWS file can't be changed after the release is done, so here
2799is some late-breaking news:
2800
2801New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2802and changes to getlocale() and setlocale().
2803
2804The new module is now enabled per default.
2805
2806It is not true that the encodings codecs cannot be used for normal
2807strings: the string.encode() (which is also present on 8-bit strings
2808!) allows using them for 8-bit strings too, e.g. to convert files from
2809cp1252 (Windows) to latin-1 or vice-versa.
2810
2811Japanese codecs are available from Tamito KAJIYAMA:
2812http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2813
2814
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002815======================================================================