blob: a039a7195cb920aa56f78bddc5e3187ed2775e7e [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
7Core and builtins
8
9Extension modules
10
11Library
12
13Tools/Demos
14
15Build
16
17C API
18
19New platforms
20
21Tests
22
23Windows
24
25
Tim Petersabf925f2001-09-28 21:53:42 +000026What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +000027Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +000028===========================
29
30Type/class unification and new-style classes
31
Guido van Rossum687ae002001-10-15 22:03:32 +000032- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +000033 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +000034 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000035 remains: the __dict__ of a new-style class is a read-only proxy; you
36 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000037 __defined__ attribute of new-style types no longer exists, for lack
38 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000039 future a __cache__ may be resurrected with a similar function, if I
40 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000041
Tim Peters1c9ca872001-10-04 06:43:12 +000042- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
43 always returned None, even when there was a class docstring).
44
45- doctest now finds and runs docstrings attached to new-style classes,
46 class methods, static methods, and properties.
47
Guido van Rossum9074ef62001-10-16 21:34:49 +000048Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +000049
Guido van Rossuma8bcf802001-10-15 15:53:58 +000050- A very subtle syntactical pitfall in list comprehensions was fixed.
51 For example: [a+b for a in 'abc', for b in 'def']. The comma in
52 this example is a mistake. Previously, this would silently let 'a'
53 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
54 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
55 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
56 Note that [a for a in <singleton>] is a convoluted way to say
57 [<singleton>] anyway, so it's not like any expressiveness is lost.
58
Guido van Rossum9074ef62001-10-16 21:34:49 +000059- getattr(obj, name, default) now only catches AttributeError, as
60 documented, rather than returning the default value for all
61 exceptions (which could mask bugs in a __getattr__ hook, for
62 example).
63
Fred Drake934d2a42001-10-18 18:18:06 +000064- Weak reference objects are now part of the core and offers a C API.
65 A bug which could allow a core dump when binary operations involved
Barry Warsawf6fb1712001-10-19 05:35:40 +000066 proxy reference has been fixed. weekref.ReferenceError is now a
67 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +000068
Guido van Rossum1c486092001-10-19 02:05:35 +000069- unicode(obj) now behaves more like str(obj), accepting arbitrary
70 objects, and calling a __unicode__ method if it exists.
71 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +000072 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +000073
Barry Warsawf6fb1712001-10-19 05:35:40 +000074- isinstance() now allows any object as the first argument and a
75 class, a type or something with a __bases__ tuple attribute for the
76 second argument. The second argument may also be a tuple of a
77 class, type, or something with __bases__, in which case isinstance()
78 will return true if the first argument is an instance of any of the
79 things contained in the second argument tuple. E.g.
80
81 isinstance(x, (A, B))
82
83 returns true if x is an instance of A or B.
84
Guido van Rossum9074ef62001-10-16 21:34:49 +000085Extension modules
86
87- thread.start_new_thread() now returns the thread ID (previously None).
88
Martin v. Löwis16dc7f42001-09-30 20:32:11 +000089- binascii has now two quopri support functions, a2b_qp and b2a_qp.
90
Guido van Rossumc524d952001-10-19 01:31:59 +000091- readline now supports setting the startup_hook and the
92 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +000093
Guido van Rossumc524d952001-10-19 01:31:59 +000094- os and posix supports chroot(), setgroups() and unsetenv() where
95 available. The stat(), fstat(), statvfs() and fstatvfs() functions
96 now return "pseudo-sequences" -- the various fields can now be
97 accessed as attributes (e.g. os.stat("/").st_mtime) but for
98 backwards compatibility they also behave as a fixed-length sequence.
99 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000100 attributes.
101
102- time: localtime(), gmtime() and strptime() now return a
103 pseudo-sequence similar to the os.stat() return value, with
104 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000105
Guido van Rossum9074ef62001-10-16 21:34:49 +0000106- Decompression objects in the zlib module now accept an optional
107 second parameter to decompress() that specifies the maximum amount
108 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000109
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000110- optional SSL support in the socket module now exports OpenSSL
111 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
112 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000113 automatically seed its PRNG. Also, the keyfile and certfile
114 arguments to socket.ssl() are now optional.
115
116- posixmodule (and by extension, the os module on POSIX platforms) now
117 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000118
Guido van Rossum9074ef62001-10-16 21:34:49 +0000119Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000120
Tim Peters7402f792001-10-02 03:53:41 +0000121- doctest now excludes functions and classes not defined by the module
122 being tested, thanks to Tim Hochberg.
123
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000124- profile now produces correct output in situations where an exception
125 raised in Python is cleared by C code (e.g. hasattr()). This used
126 to cause wrong output, including spurious claims of recursive
127 functions and attribution of time spent to the wrong function.
128
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000129 The code and documentation for the derived OldProfile and HotProfile
130 profiling classes was removed. The code hasn't worked for years (if
131 you tried to use them, they raised exceptions). OldProfile
132 intended to reproduce the behavior of the profiler Python used more
133 than 7 years ago, and isn't interesting anymore. HotProfile intended
134 to provide a faster profiler (but producing less information), and
135 that's a worthy goal we intend to meet via a different approach (but
136 without losing information).
137
Tim Peterscce092d2001-10-09 05:31:56 +0000138- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000139 a much better system-specific calibration constant. The constant can
140 now be specified in an instance constructor, or as a Profile class or
141 instance variable, instead of by editing profile.py's source code.
142 Calibration must still be done manually (see the docs for the profile
143 module).
144
145 Note that Profile.calibrate() must be overriden by subclasses.
146 Improving the accuracy required exploiting detailed knowledge of
147 profiler internals; the earlier method abstracted away the details
148 and measured a simplified model instead, but consequently computed
149 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000150
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000151- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000152 which indicates whether output is intended for the header 'Q'
153 encoding.
154
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000155- The SocketServer.ThreadingMixIn class now closes the request after
156 finish_request() returns. (Not when it errors out though.)
157
Barry Warsawf6fb1712001-10-19 05:35:40 +0000158- The nntplib module's NNTP.body() method has grown a `file' argument
159 to allow saving the message body to a file.
160
161- The email package has added a class email.Parser.HeaderParser which
162 only parses headers and does not recurse into the message's body.
163 Also, the module/class MIMEAudio has been added for representing
164 audio data (contributed by Anthony Baxter).
165
166- ftplib should be able to handle files > 2GB.
167
168- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
169 ON, and OFF.
170
Guido van Rossumed554f62001-10-02 23:15:37 +0000171Tools/Demos
172
173- Demo/dns was removed. It no longer serves any purpose; a package
174 derived from it is now maintained by Anthony Baxter, see
175 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000176
Barry Warsawf6fb1712001-10-19 05:35:40 +0000177- The freeze tool has been made more robust, and two new options have
178 been added: -X and -E.
179
Tim Petersabf925f2001-09-28 21:53:42 +0000180Build
181
Barry Warsawf6fb1712001-10-19 05:35:40 +0000182- configure will use CXX in LINKCC if CXX is used to build main() and
183 the system requires to link a C++ main using the C++ compiler.
184
Tim Petersabf925f2001-09-28 21:53:42 +0000185C API
186
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000187- The documentation for the tp_compare slot is updated to require that
188 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
189 not correct. This is not yet enforced but will be enforced in
190 Python 2.3; even later, we may use -2 to indicate errors and +2 for
191 "NotImplemented". Right now, -1 should be used for an error return.
192
Tim Petersd38b1c72001-09-30 05:09:37 +0000193- PyLong_AsLongLong() now accepts int (as well as long) arguments.
194 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
195 as long) arguments.
196
Guido van Rossum3c288632001-10-16 21:13:49 +0000197- PyThread_start_new_thread() now returns a long int giving the thread
198 ID, if one can be calculated; it returns -1 for error, 0 if no
199 thread ID is calculated (this is an incompatible change, but only
200 the thread module used this API). This code has only really been
201 tested on Linux and Windows; other platforms please beware (and
202 report any bugs or strange behavior).
203
Guido van Rossum1c486092001-10-19 02:05:35 +0000204- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
205 input.
206
Tim Petersabf925f2001-09-28 21:53:42 +0000207New platforms
208
209Tests
210
211Windows
212
Tim Peters04cf1d32001-10-09 22:39:40 +0000213- Installer: If you install IDLE, and don't disable file-extension
214 registration, a new "Edit with IDLE" context (right-click) menu entry
215 is created for .py and .pyw files.
216
Tim Peters1ce3cf72001-10-01 17:58:40 +0000217- The signal module now supports SIGBREAK on Windows, thanks to Steven
218 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
219 action remains to call Win32 ExitProcess(). This can be changed via
220 signal.signal(). For example:
221
222 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
223 # (SIGINT) behavior.
224 import signal
225 signal.signal(signal.SIGBREAK,
226 signal.default_int_handler)
227
228 try:
229 while 1:
230 pass
231 except KeyboardInterrupt:
232 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
233 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
234 # program without the possibility for any Python-level cleanup).
235 print "Clean exit"
236
Tim Petersabf925f2001-09-28 21:53:42 +0000237
Tim Petersb07352e2001-09-08 01:25:47 +0000238What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000239Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000240===========================
241
Guido van Rossum808eea72001-09-25 04:15:41 +0000242Type/class unification and new-style classes
243
244- pydoc and inspect are now aware of new-style classes;
245 e.g. help(list) at the interactive prompt now shows proper
246 documentation for all operations on list objects.
247
248- Applications using Jim Fulton's ExtensionClass module can now safely
249 be used with Python 2.2. In particular, Zope 2.4.1 now works with
250 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
251 examples also work again. It is hoped that Gtk and Boost also work
252 with 2.2a4 and beyond. (If you can confirm this, please write
253 webmaster@python.org; if there are still problems, please open a bug
254 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000255
Tim Peters66c1a522001-09-24 21:17:50 +0000256- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
257 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
258 in the constructed property object. fget, fset and fdel weren't
259 discoverable from Python in 2.2a3. __doc__ is new, and allows to
260 associate a docstring with a property.
261
Guido van Rossum808eea72001-09-25 04:15:41 +0000262- Comparison overloading is now more completely implemented. For
263 example, a str subclass instance can properly be compared to a str
264 instance, and it can properly overload comparison. Ditto for most
265 other built-in object types.
266
267- The repr() of new-style classes has changed; instead of <type
268 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
269 *except* for built-in types, which are still rendered as <type
270 'Foo'> (to avoid upsetting existing code that might parse or
271 otherwise rely on repr() of certain type objects).
272
273- The repr() of new-style objects is now always <Foo object at XXX>;
274 previously, it was sometimes <Foo instance at XXX>.
275
276- For new-style classes, what was previously called __getattr__ is now
277 called __getattribute__. This method, if defined, is called for
278 *every* attribute access. A new __getattr__ hook mor similar to the
279 one in classic classes is defined which is called only if regular
280 attribute access raises AttributeError; to catch *all* attribute
281 access, you can use __getattribute__ (for new-style classes). If
282 both are defined, __getattribute__ is called first, and if it raises
283 AttributeError, __getattr__ is called.
284
285- The __class__ attribute of new-style objects can be assigned to.
286 The new class must have the same C-level object layout as the old
287 class.
288
289- The builtin file type can be subclassed now. In the usual pattern,
290 "file" is the name of the builtin type, and file() is a new builtin
291 constructor, with the same signature as the builtin open() function.
292 file() is now the preferred way to open a file.
293
294- Previously, __new__ would only see sequential arguments passed to
295 the type in a constructor call; __init__ would see both sequential
296 and keyword arguments. This made no sense whatsoever any more, so
297 now both __new__ and __init__ see all arguments.
298
299- Previously, hash() applied to an instance of a subclass of str or
300 unicode always returned 0. This has been repaired.
301
302- Previously, an operation on an instance of a subclass of an
303 immutable type (int, long, float, complex, tuple, str, unicode),
304 where the subtype didn't override the operation (and so the
305 operation was handled by the builtin type), could return that
306 instance instead a value of the base type. For example, if s was of
307 a str sublass type, s[:] returned s as-is. Now it returns a str
308 with the same value as s.
309
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000310- Provisional support for pickling new-style objects has been added.
311
Guido van Rossum808eea72001-09-25 04:15:41 +0000312Core
313
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000314- file.writelines() now accepts any iterable object producing strings.
315
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000316- PyUnicode_FromEncodedObject() now works very much like
317 PyObject_Str(obj) in that it tries to use __str__/tp_str
318 on the object if the object is not a string or buffer. This
319 makes unicode() behave like str() when applied to non-string/buffer
320 objects.
321
Martin v. Löwis2777c022001-09-19 13:47:32 +0000322- PyFile_WriteObject now passes Unicode object to the file's write
323 method. As a result, all file-like object which may be the target
324 of a print statement must support Unicode objects, i.e. they must
325 at least convert them into ASCII strings.
326
Guido van Rossum624c8af2001-09-18 15:21:04 +0000327- Thread scheduling on Solaris should be improved; it is no longer
328 necessary to insert a small sleep at the start of a thread in order
329 to let other runnable threads be scheduled.
330
Tim Petersb07352e2001-09-08 01:25:47 +0000331Library
332
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000333- StringIO.StringIO instances and cStringIO.StringIO instances support
334 read character buffer compatible objects for their .write() methods.
335 These objects are converted to strings and then handled as such
336 by the instances.
337
Barry Warsaw2f600732001-09-24 04:28:10 +0000338- The "email" package has been added. This is basically a port of the
339 mimelib package <http://sf.net/projects/mimelib> with API changes
340 and some implementations updated to use iterators and generators.
341
Tim Peters8a9c2842001-09-22 21:30:22 +0000342- difflib.ndiff() and difflib.Differ.compare() are generators now. This
343 restores the ability of Tools/scripts/ndiff.py to start producing output
344 before the entire comparison is complete.
345
Barry Warsaw58b072d2001-09-22 04:44:21 +0000346- StringIO.StringIO instances and cStringIO.StringIO instances support
347 iteration just like file objects (i.e. their .readline() method is
348 called for each iteration until it returns an empty string).
349
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000350- The codecs module has grown four new helper APIs to access
351 builtin codecs: getencoder(), getdecoder(), getreader(),
352 getwriter().
353
Guido van Rossum624c8af2001-09-18 15:21:04 +0000354- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
355 simplifies writing XML RPC servers.
356
Barry Warsaw647d5e82001-09-28 17:01:02 +0000357- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000358 after interpretation of symbolic links. On non-Unix systems, this
359 is an alias for os.path.abspath().
360
Tim Peters16a77ad2001-09-08 04:00:12 +0000361- operator.indexOf() (PySequence_Index() in the C API) now works with any
362 iterable object.
363
Guido van Rossum624c8af2001-09-18 15:21:04 +0000364- smtplib now supports various authentication and security features of
365 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000366
Guido van Rossum624c8af2001-09-18 15:21:04 +0000367- hmac: a new module implementing keyed hashing for message
368 authentication.
369
370- mimetypes now recognizes more extensions and file types. At the
371 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000372
Guido van Rossum624c8af2001-09-18 15:21:04 +0000373- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000374 Python 2.2 bytecode generation. It has also been promoted from a
375 Tool to a standard library package. (Tools/compiler still exists as
376 a sample driver.)
377
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000378Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000379
Tim Petersb07352e2001-09-08 01:25:47 +0000380Build
381
Guido van Rossum624c8af2001-09-18 15:21:04 +0000382- Large file support (LFS) is now automatic when the platform supports
383 it; no more manual configuration tweaks are needed. On Linux, at
384 least, it's possible to have a system whose C library supports large
385 files but whose kernel doesn't; in this case, large file support is
386 still enabled but doesn't do you any good unless you upgrade your
387 kernel or share your Python executable with another system whose
388 kernel has large file support.
389
390- The configure script now supplies plausible defaults in a
391 cross-compilation environment. This doesn't mean that the supplied
392 values are always correct, or that cross-compilation now works
393 flawlessly -- but it's a first step (and it shuts up most of
394 autoconf's warnings about AC_TRY_RUN).
395
396- The Unix build is now a bit less chatty, courtesy of the parser
397 generator. The build is completely silent (except for errors) when
398 using "make -s", thanks to a -q option to setup.py.
399
Tim Petersb07352e2001-09-08 01:25:47 +0000400C API
401
Guido van Rossum624c8af2001-09-18 15:21:04 +0000402- The "structmember" API now supports some new flag bits to deny read
403 and/or write access to attributes in restricted execution mode.
404
Tim Petersb07352e2001-09-08 01:25:47 +0000405New platforms
406
Guido van Rossum624c8af2001-09-18 15:21:04 +0000407- Compaq's iPAQ handheld, running the "familiar" Linux distribution
408 (http://familiar.handhelds.org).
409
Tim Petersb07352e2001-09-08 01:25:47 +0000410Tests
411
Tim Peters8a9c2842001-09-22 21:30:22 +0000412- The "classic" standard tests, which work by comparing stdout to
413 an expected-output file under Lib/test/output/, no longer stop at
414 the first mismatch. Instead the test is run to completion, and a
415 variant of ndiff-style comparison is used to report all differences.
416 This is much easier to understand than the previous style of reporting.
417
418- The unittest-based standard tests now use regrtest's test_main()
419 convention, instead of running as a side-effect of merely being
420 imported. This allows these tests to be run in more natural and
421 flexible ways as unittests, outside the regrtest framework.
422
423- regrtest.py is much better integrated with unittest and doctest now,
424 especially in regard to reporting errors.
425
Tim Petersb07352e2001-09-08 01:25:47 +0000426Windows
427
Guido van Rossum624c8af2001-09-18 15:21:04 +0000428- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000429 that support it (NTFS under Windows 2000). See "What's New in
430 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000431
Tim Petersb07352e2001-09-08 01:25:47 +0000432
Tim Petersedc99312001-08-22 21:36:50 +0000433What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000434Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000435===========================
436
437Core
438
Tim Peters9fffa3e2001-09-04 05:14:19 +0000439- Conversion of long to float now raises OverflowError if the long is too
440 big to represent as a C double.
441
Tim Peters32f453e2001-09-03 08:35:41 +0000442- The 3-argument builtin pow() no longer allows a third non-None argument
443 if either of the first two arguments is a float, or if both are of
444 integer types and the second argument is negative (in which latter case
445 the arguments are converted to float, so this is really the same
446 restriction).
447
Tim Peters5d2b77c2001-09-03 05:47:38 +0000448- The builtin dir() now returns more information, and sometimes much
449 more, generally naming all attributes of an object, and all attributes
450 reachable from the object via its class, and from its class's base
451 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
452 an empty list. In 2.2a3,
453
454 >>> dir([])
455 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
456 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
457 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
458 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
459 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
460 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
461 'reverse', 'sort']
462
463 dir(module) continues to return only the module's attributes, though.
464
Tim Petersbdee63f2001-09-02 03:40:59 +0000465- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000466 than raising OverflowError. This is a partial implementation of PEP
467 237. You can use -Wdefault::OverflowWarning to enable a warning for
468 this situation, and -Werror::OverflowWarning to revert to the old
469 OverflowError exception.
470
Guido van Rossum61c345f2001-09-04 03:26:15 +0000471- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000472 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000473 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
474 -Qold, meaning the / operator has its classic meaning and no
475 warnings are issued. Using -Qwarn issues a run-time warning about
476 all uses of classic division for int and long arguments; -Qwarnall
477 also warns about classic division for float and complex arguments
478 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
479 new division by default, but only in the __main__ module. You can
480 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
481 __main__ module new division, and warns about classic division
482 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000483
Tim Petersbdee63f2001-09-02 03:40:59 +0000484- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000485 long, float, str, unicode, and tuple. (The types complex, list and
486 dictionary can also be subclassed; this was introduced earlier.)
487 Note that restrictions apply when subclassing immutable built-in
488 types: you can only affect the value of the instance by overloading
489 __new__. You can add mutable attributes, and the subclass instances
490 will have a __dict__ attribute, but you cannot change the "value"
491 (as implemented by the base class) of an immutable subclass instance
492 once it is created.
493
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000494- The dictionary constructor now takes an optional argument, a
495 mapping-like object, and initializes the dictionary from its
496 (key, value) pairs.
497
Tim Petersbdee63f2001-09-02 03:40:59 +0000498- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000499 "cooperative super calls" in a multiple inheritance setting. For an
500 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
501
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000502- A new built-in type, property, has been added. This enables the
503 creation of "properties". These are attributes implemented by
504 getter and setter functions (or only one of these for read-only or
505 write-only attributes), without the need to override __getattr__.
506 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000507
Tim Petersbdee63f2001-09-02 03:40:59 +0000508- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000509 liberalized, to allow leading zeroes. Examples of literals now
510 legal that were SyntaxErrors before:
511
512 00.0 0e3 0100j 07.5 00000000000000000008.
513
Tim Petersbdee63f2001-09-02 03:40:59 +0000514- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000515 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
516
Tim Petersedc99312001-08-22 21:36:50 +0000517Library
518
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000519- telnetlib includes symbolic names for the options, and support for
520 setting an option negotiation callback.
521
Tim Petersa40c7932001-09-05 22:36:56 +0000522- The new C standard no longer requires that math libraries set errno to
523 ERANGE on overflow. For platform libraries that exploit this new
524 freedom, Python's overflow-checking was wholly broken. A new overflow-
525 checking scheme attempts to repair that, but may not be reliable on all
526 platforms (C doesn't seem to provide anything both useful and portable
527 in this area anymore).
528
Martin v. Löwis44f86962001-09-05 13:44:54 +0000529- Asynchronous timeout actions are available through the new class
530 threading.Timer.
531
Tim Peters78526162001-09-05 00:53:45 +0000532- math.log and math.log10 now return sensible results for even huge
533 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
534
Tim Petersbdee63f2001-09-02 03:40:59 +0000535- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000536 currently held. See the docs for the imp module.
537
Tim Petersbdee63f2001-09-02 03:40:59 +0000538- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000539 dumps containing ints written on platforms where Python ints are 8 bytes.
540 When read on a box where Python ints are 4 bytes, such values are
541 converted to Python longs.
542
Tim Petersbdee63f2001-09-02 03:40:59 +0000543- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000544 code objects is no longer allowed. This plugs a security hole.
545
Steve Purcell6091cd62001-09-06 16:05:17 +0000546- unittest.TestResult instances no longer store references to tracebacks
547 generated by test failures. This prevents unexpected dangling references
548 to objects that should be garbage collected between tests.
549
Tim Petersedc99312001-08-22 21:36:50 +0000550Tools
551
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000552- Tools/scripts/fixdiv.py has been added which can be used to fix
553 division operators as per PEP 238.
554
Tim Petersedc99312001-08-22 21:36:50 +0000555Build
556
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000557- If you are an adventurous person using Mac OS X you may want to look at
558 Mac/OSX. There is a Makefile there that will build Python as a real Mac
559 application, which can be used for experimenting with Carbon or Cocoa.
560 Discussion of this on pythonmac-sig, please.
561
Tim Peters7eea37e2001-09-04 22:08:56 +0000562C API
563
564- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000565
Tim Peters9fffa3e2001-09-04 05:14:19 +0000566- Note that PyLong_AsDouble can fail! This has always been true, but no
567 callers checked for it. It's more likely to fail now, because overflow
568 errors are properly detected now. The proper way to check:
569
570 double x = PyLong_AsDouble(some_long_object);
571 if (x == -1.0 && PyErr_Occurred()) {
572 /* The conversion failed. */
573 }
574
Tim Petersbdee63f2001-09-02 03:40:59 +0000575- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000576 compile but will not participate in GC. To upgrade an extension
577 module:
578
579 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000580
Neil Schemenauer4042c692001-08-30 15:38:01 +0000581 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
582 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000583
Neil Schemenauer4042c692001-08-30 15:38:01 +0000584 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
585 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000586
Neil Schemenauer4042c692001-08-30 15:38:01 +0000587 - remove PyGC_HEAD_SIZE from object size calculations
588
589 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
590
Tim Petersbdee63f2001-09-02 03:40:59 +0000591- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000592 These can be used safely to construct string objects from a
593 sprintf-style format string (similar to the format string supported
594 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000595
Tim Petersedc99312001-08-22 21:36:50 +0000596New platforms
597
Tim Petersb7da0902001-09-02 23:01:43 +0000598- Stephen Hansen contributed patches sufficient to get a clean compile
599 under Borland C (Windows), but he reports problems running it and ran
600 out of time to complete the port. Volunteers? Expect a MemoryError
601 when importing the types module; this is probably shallow, and
602 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000603
Tim Petersedc99312001-08-22 21:36:50 +0000604Tests
605
606Windows
607
Tim Peters6e13a562001-09-06 00:32:15 +0000608- Large file support is now enabled on Win32 platforms as well as on
609 Win64. This means that, for example, you can use f.tell() and f.seek()
610 to manipulate files larger than 2 gigabytes (provided you have enough
611 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000612 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
613 filesize limit, and large file support makes no difference there.
614 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
615 NTFS has no practical limit on file size, and files of any size can be
616 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000617
Tim Petersbdee63f2001-09-02 03:40:59 +0000618- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000619 points to command.com (patch from Brian Quinlan).
620
Tim Petersedc99312001-08-22 21:36:50 +0000621
Tim Peters20f51a72001-07-21 02:31:40 +0000622What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000623Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000624===========================
625
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000626Build
627
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000628- Tim Peters developed a brand new Windows installer using Wise 8.1,
629 generously donated to us by Wise Solutions.
630
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000631- configure supports a new option --enable-unicode, with the values
632 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
633 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000634
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000635- A new configure option --enable-framework builds a Mac OS X framework,
636 which "make frameworkinstall" will install. This provides a starting
637 point for more mac-like functionality, join pythonmac-sig@python.org
638 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000639
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000640- The NeXT platform is no longer supported.
641
642- The `new' module is now statically linked.
643
Tim Peters0afb6092001-08-15 06:06:44 +0000644Tools
645
646- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000647 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000648 the module docstring for details.
649
Tim Peters20f51a72001-07-21 02:31:40 +0000650Tests
651
Tim Peters5e824c32001-08-12 22:25:01 +0000652- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000653 platforms, allowing to give clearer test result output. regrtest
654 also has optional --use/-u switch to run normally disabled tests
655 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000656
Tim Peters20f51a72001-07-21 02:31:40 +0000657- Several new tests in the standard test suite, with special thanks to
658 Nick Mathewson.
659
660Core
661
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000662- The floor division operator // has been added as outlined in PEP
663 238. The / operator still provides classic division (and will until
664 Python 3.0) unless "from __future__ import division" is included, in
665 which case the / operator will provide true division. The operator
666 module provides truediv() and floordiv() functions. Augmented
667 assignment variants are included, as are the equivalent overloadable
668 methods and C API methods. See the PEP for a full discussion:
669 <http://python.sf.net/peps/pep-0238.html>
670
Tim Peters6cd6a822001-08-17 22:11:27 +0000671- Future statements are now effective in simulated interactive shells
672 (like IDLE). This should "just work" by magic, but read Michael
673 Hudson's "Future statements in simulated shells" PEP 264 for full
674 details: <http://python.sf.net/peps/pep-0264.html>.
675
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000676- The type/class unification (PEP 252-253) was integrated into the
677 trunk and is not so tentative any more (the exact specification of
678 some features is still tentative). A lot of work has done on fixing
679 bugs and adding robustness and features (performance still has to
680 come a long way).
681
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000682- Warnings about a mismatch in the Python API during extension import
683 now use the Python warning framework (which makes it possible to
684 write filters for these warnings).
685
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000686- A function's __dict__ (aka func_dict) will now always be a
687 dictionary. It used to be possible to delete it or set it to None,
688 but now both actions raise TypeErrors. It is still legal to set it
689 to a dictionary object. Getting func.__dict__ before any attributes
690 have been assigned now returns an empty dictionary instead of None.
691
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000692- A new command line option, -E, was added which disables the use of
693 all environment variables, or at least those that are specifically
694 significant to Python. Usually those have a name starting with
695 "PYTHON". This was used to fix a problem where the tests fail if
696 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
697 older distribution.
698
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000699Library
700
Tim Peters5e824c32001-08-12 22:25:01 +0000701- New class Differ and new functions ndiff() and restore() in difflib.py.
702 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000703 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000704
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000705- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
706 value using the minimal quoting required for the value; more
707 reliable than using xml.sax.saxutils.escape() for attribute values.
708
709- Readline completion support for cmd.Cmd was added.
710
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000711- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
712
713- Added function threading.BoundedSemaphore()
714
715- Added Ka-Ping Yee's cgitb.py module.
716
717- The `new' module now exposes the CO_xxx flags.
718
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000719New platforms
720
721C API
722
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000723- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
724 which provide a cross-platform implementations for the
725 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
726 the standard sprintf() and vsprintf() C lib APIs, these versions
727 apply bounds checking on the used buffer which enhances protection
728 against buffer overruns.
729
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000730- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000731 and extensions using different Unicode widths is rendered next to
732 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000733 will result in an ImportError. Unicode extensions writers must make
734 sure to check the Unicode width compatibility in their extensions by
735 using at least one of the mangled Unicode APIs in the extension.
736
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000737- Two new flags METH_NOARGS and METH_O are available in method definition
738 tables to simplify implementation of methods with no arguments and a
739 single untyped argument. Calling such methods is more efficient than
740 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
741 deprecated.
742
Tim Petersc1731372001-08-04 08:12:36 +0000743Windows
744
745- "import module" now compiles module.pyw if it exists and nothing else
746 relevant is found.
747
Tim Peters20f51a72001-07-21 02:31:40 +0000748
Guido van Rossum55a78992001-07-17 17:22:32 +0000749What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000750===========================
751
752Core
Tim Petersa814db52001-05-14 07:05:58 +0000753
Tim Peters6d6c1a32001-08-02 04:15:00 +0000754- TENTATIVELY, a large amount of code implementing much of what's
755 described in PEP 252 (Making Types Look More Like Classes) and PEP
756 253 (Subtyping Built-in Types) was added. This will be released
757 with Python 2.2a1. Documentation will be provided separately
758 through http://www.python.org/2.2/. The purpose of releasing this
759 with Python 2.2a1 is to test backwards compatibility. It is
760 possible, though not likely, that a decision is made not to release
761 this code as part of 2.2 final, if any serious backwards
762 incompapatibilities are found during alpha testing that cannot be
763 repaired.
764
Guido van Rossum55a78992001-07-17 17:22:32 +0000765- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000766 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000767 more 'yield' statements. See PEP 255. Since this adds a new
768 keyword to the language, this feature must be enabled by including a
769 future statement: "from __future__ import generators" (see PEP 236).
770 Generators will become a standard feature in a future release
771 (probably 2.3). Without this future statement, 'yield' remains an
772 ordinary identifier, but a warning is issued each time it is used.
773 (These warnings currently don't conform to the warnings framework of
774 PEP 230; we intend to fix this in 2.2a2.)
775
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000776- The UTF-16 codec was modified to be more RFC compliant. It will now
777 only remove BOM characters at the start of the string and then
778 only if running in native mode (UTF-16-LE and -BE won't remove a
779 leading BMO character).
780
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000781- Strings now have a new method .decode() to complement the already
782 existing .encode() method. These two methods provide direct access
783 to the corresponding decoders and encoders of the registered codecs.
784
785 To enhance the usability of the .encode() method, the special
786 casing of Unicode object return values was dropped (Unicode objects
787 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000788
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000789 Both methods will now return whatever the codec in charge of the
790 requested encoding returns as object, e.g. Unicode codecs will
791 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
792 will return u"äöü"). This enables codec writer to create codecs
793 for various simple to use conversions.
794
795 New codecs were added to demonstrate these new features (the .encode()
796 and .decode() columns indicate the type of the returned objects):
797
798 Name | .encode() | .decode() | Description
799 ----------------------------------------------------------------------
800 uu | string | string | UU codec (e.g. for email)
801 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000802 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000803 zlib | string | string | zlib compression
804 hex | string | string | 2-byte hex codec
805 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
806
Mark Hammond2a0af792001-05-14 03:09:36 +0000807- Some operating systems now support the concept of a default Unicode
808 encoding for file system operations. Notably, Windows supports 'mbcs'
809 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000810 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000811 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000812
813 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000814 functions that return filenames (such as os.listdir()) to return Python
815 string objects pre-encoded using the default file system encoding for
816 the platform. As this encoding is likely to be different from Python's
817 default encoding, converting this name to a Unicode object before passing
818 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000819 would attempt to use its default encoding (generally ASCII) rather than
820 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000821
Tim Petersa814db52001-05-14 07:05:58 +0000822 In general, this change simply removes surprises when working with
823 Unicode and the file system, making these operations work as you expect,
824 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000825 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000826
Tim Peters61dff2b2001-05-08 15:43:37 +0000827- Float (and complex) literals in source code were evaluated to full
828 precision only when running from a .py file; the same code loaded from a
829 .pyc (or .pyo) file could suffer numeric differences starting at about the
830 12th significant decimal digit. For example, on a machine with IEEE-754
831 floating arithmetic,
832
833 x = 9007199254740992.0
834 print long(x)
835
836 printed 9007199254740992 if run directly from .py, but 9007199254740000
837 if from a compiled (.pyc or .pyo) file. This was due to marshal using
838 str(float) instead of repr(float) when building code objects. marshal
839 now uses repr(float) instead, which should reproduce floats to full
840 machine precision (assuming the platform C float<->string I/O conversion
841 functions are of good quality).
842
843 This may cause floating-point results to change in some cases, and
844 usually for the better, but may also cause numerically unstable
845 algorithms to break.
846
Tim Peters2f228e72001-05-13 00:19:31 +0000847- The implementation of dicts suffers fewer collisions, which has speed
848 benefits. However, the order in which dict entries appear in dict.keys(),
849 dict.values() and dict.items() may differ from previous releases for a
850 given dict. Nothing is defined about this order, so no program should
851 rely on it. Nevertheless, it's easy to write test cases that rely on the
852 order by accident, typically because of printing the str() or repr() of a
853 dict to an "expected results" file. See Lib/test/test_support.py's new
854 sortdict(dict) function for a simple way to display a dict in sorted
855 order.
856
Tim Peters7a3bfc32001-06-12 01:22:22 +0000857- Many other small changes to dicts were made, resulting in faster
858 operation along the most common code paths.
859
Guido van Rossum10315822001-05-01 20:54:30 +0000860- Dictionary objects now support the "in" operator: "x in dict" means
861 the same as dict.has_key(x).
862
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000863- The update() method of dictionaries now accepts generic mapping
864 objects. Specifically the argument object must support the .keys()
865 and __getitem__() methods. This allows you to say, for example,
866 {}.update(UserDict())
867
Guido van Rossum10315822001-05-01 20:54:30 +0000868- Iterators were added; this is a generalized way of providing values
869 to a for loop. See PEP 234. There's a new built-in function iter()
870 to return an iterator. There's a new protocol to get the next value
871 from an iterator using the next() method (in Python) or the
872 tp_iternext slot (in C). There's a new protocol to get iterators
873 using the __iter__() method (in Python) or the tp_iter slot (in C).
874 Iterating (i.e. a for loop) over a dictionary generates its keys.
875 Iterating over a file generates its lines.
876
Tim Petersf553f892001-05-01 20:45:31 +0000877- The following functions were generalized to work nicely with iterator
878 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000879 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000880 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
881 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000882 join() method of strings
883 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000884 'x in y' and 'x not in y' (PySequence_Contains() in C API)
885 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000886 right-hand side of assignment statements with multiple targets, such as
887 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000888
Tim Petersd85e1022001-05-11 21:51:48 +0000889- Accessing module attributes is significantly faster (for example,
890 random.random or os.path or yourPythonModule.yourAttribute).
891
Tim Peterse63415e2001-05-08 04:38:29 +0000892- Comparing dictionary objects via == and != is faster, and now works even
893 if the keys and values don't support comparisons other than ==.
894
Tim Peters95bf9392001-05-10 08:32:44 +0000895- Comparing dictionaries in ways other than == and != is slower: there were
896 insecurities in the dict comparison implementation that could cause Python
897 to crash if the element comparison routines for the dict keys and/or
898 values mutated the dicts. Making the code bulletproof slowed it down.
899
Tim Peterseb28ef22001-06-02 05:27:19 +0000900- Collisions in dicts are resolved via a new approach, which can help
901 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000902 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000903 faster now. Thanks to Christian Tismer for pointing out the cause and
904 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000905
Tim Peters52e155e2001-06-16 05:42:57 +0000906- repr() is much faster for large containers (dict, list, tuple).
907
908
Tim Petersa814db52001-05-14 07:05:58 +0000909Library
910
Fred Drake960fdf92001-07-20 18:38:26 +0000911- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
912 were added to the string module. These a locale-indenpendent
913 constants, unlike letters, lowercase, and uppercase. These are now
914 use in appropriate locations in the standard library.
915
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000916- The flags used in dlopen calls can now be configured using
917 sys.setdlopenflags and queried using sys.getdlopenflags.
918
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000919- Fredrik Lundh's xmlrpclib is now a standard library module. This
920 provides full client-side XML-RPC support. In addition,
921 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
922 one asyncore-based). Thanks to Eric Raymond for the documentation.
923
Guido van Rossum643d3912001-07-05 14:46:25 +0000924- The xrange() object is simplified: it no longer supports slicing,
925 repetition, comparisons, efficient 'in' checking, the tolist()
926 method, or the start, stop and step attributes. See PEP 260.
927
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000928- A new function fnmatch.filter to filter lists of file names was added.
929
Barry Warsawffd674d2001-05-22 16:00:10 +0000930- calendar.py uses month and day names based on the current locale.
931
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000932- strop is now *really* obsolete (this was announced before with 1.6),
933 and issues DeprecationWarning when used (except for the four items
934 that are still imported into string.py).
935
Tim Petersa814db52001-05-14 07:05:58 +0000936- Cookie.py now sorts key+value pairs by key in output strings.
937
938- pprint.isrecursive(object) didn't correctly identify recursive objects.
939 Now it does.
940
Tim Peters95b3f782001-05-14 18:39:41 +0000941- pprint functions now much faster for large containers (tuple, list, dict).
942
Tim Peters7b9542a2001-06-10 23:40:19 +0000943- New 'q' and 'Q' format codes in the struct module, corresponding to C
944 types "long long" and "unsigned long long" (on Windows, __int64). In
945 native mode, these can be used only when the platform C compiler supports
946 these types (when HAVE_LONG_LONG is #define'd by the Python config
947 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000948 In standard mode, 'q' and 'Q' are supported on all platforms, and are
949 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000950
Guido van Rossum83213cc2001-06-12 16:48:52 +0000951- The site module installs a new built-in function 'help' that invokes
952 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
953 it displays a message reminding the user to use 'help()' or
954 'help(object)'.
955
Tim Petersa814db52001-05-14 07:05:58 +0000956Tests
957
958- New test_mutants.py runs dict comparisons where the key and value
959 comparison operators mutute the dicts randomly during comparison. This
960 rapidly causes Python to crash under earlier releases (not for the faint
961 of heart: it can also cause Win9x to freeze or reboot!).
962
963- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000964 pprint.isreadable() return sensible results. Also verifies that simple
965 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000966
Tim Peters4324aa32001-05-28 22:30:08 +0000967C API
968
969- Removed the unused last_is_sticky argument from the internal
970 _PyTuple_Resize(). If this affects you, you were cheating.
971
972
Guido van Rossum55a78992001-07-17 17:22:32 +0000973======================================================================
974
975
Guido van Rossumffe13be2001-04-16 18:46:45 +0000976What's New in Python 2.1 (final)?
977=================================
978
979We only changed a few things since the last release candidate, all in
980Python library code:
981
982- A bug in the locale module was fixed that affected locales which
983 define no grouping for numeric formatting.
984
985- A few bugs in the weakref module's implementations of weak
986 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
987 and the test suite was updated to check for these bugs.
988
989- An old bug in the os.path.walk() function (introduced in Python
990 2.0!) was fixed: a non-existent file would cause an exception
991 instead of being ignored.
992
993- Fixed a few bugs in the new symtable module found by Neil Norwitz's
994 PyChecker.
995
996
Guido van Rossum5b08f132001-04-16 02:05:23 +0000997What's New in Python 2.1c2?
998===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000999
Guido van Rossum5b08f132001-04-16 02:05:23 +00001000A flurry of small changes, and one showstopper fixed in the nick of
1001time made it necessary to release another release candidate. The list
1002here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001003
Guido van Rossum5b08f132001-04-16 02:05:23 +00001004Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001005
Guido van Rossum5b08f132001-04-16 02:05:23 +00001006- Tim discovered a nasty bug in the dictionary code, caused by
1007 PyDict_Next() calling dict_resize(), and the GC code's use of
1008 PyDict_Next() violating an assumption in dict_items(). This was
1009 fixed with considerable amounts of band-aid, but the net effect is a
1010 saner and more robust implementation.
1011
1012- Made a bunch of symbols static that were accidentally global.
1013
1014Build and Ports
1015
1016- The setup.py script didn't check for a new enough version of zlib
1017 (1.1.3 is needed). Now it does.
1018
1019- Changed "make clean" target to also remove shared libraries.
1020
1021- Added a more general warning about the SGI Irix optimizer to README.
1022
1023Library
1024
1025- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1026 omitted the slash between host and file.html.
1027
1028- The mailbox module's _Mailbox class contained a completely broken
1029 and undocumented seek() method. Ripped it out.
1030
1031- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1032 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1033
1034- Fixed a few last-minute bugs in unittest.
1035
1036Extensions
1037
1038- Reverted the patch to the OpenSSL code in socketmodule.c to support
1039 RAND_status() and the EGD, and the subsequent patch that tried to
1040 fix it for pre-0.9.5 versions; the problem with the patch is that on
1041 some systems it issues a warning whenever socket is imported, and
1042 that's unacceptable.
1043
1044Tests
1045
1046- Fixed the pickle tests to work with "import test.test_pickle".
1047
1048- Tweaked test_locale.py to actually run the test Windows.
1049
1050- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1051 not "wb" (which is not a valid mode at all).
1052
1053- Fix pstats browser crashes. Import readline if it exists to make
1054 the user interface nicer.
1055
1056- Add "import thread" to the top of test modules that import the
1057 threading module (test_asynchat and test_threadedtempfile). This
1058 prevents test failures caused by a broken threading module resulting
1059 from a previously caught failed import.
1060
1061- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1062 needed on some platforms (e.g. Solaris 8) when the tests are run
1063 twice in succession.
1064
1065- Skip rather than fail test_sunaudiodev if no audio device is found.
1066
1067
1068What's New in Python 2.1c1?
1069===========================
1070
1071This list was significantly updated when 2.1c2 was released; the 2.1c1
1072release didn't mention most changes that were actually part of 2.1c1:
1073
1074Legal
1075
1076- Copyright was assigned to the Python Software Foundation (PSF) and a
1077 PSF license (very similar to the CNRI license) was added.
1078
1079- The CNRI copyright notice was updated to include 2001.
1080
1081Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001082
Guido van Rossumc9932722001-04-12 02:31:27 +00001083- After a public outcry, assignment to __debug__ is no longer illegal;
1084 instead, a warning is issued. It will become illegal in 2.2.
1085
Guido van Rossum5b08f132001-04-16 02:05:23 +00001086- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1087 "%#x" now always prepends "0x", even if the value is zero.
1088
1089- Fixed some nits in the bytecode compiler.
1090
1091- Fixed core dumps when calling certain kinds of non-functions.
1092
1093- Fixed various core dumps caused by reference count bugs.
1094
1095Build and Ports
1096
1097- Use INSTALL_SCRIPT to install script files.
1098
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001099- New port: SCO Unixware 7, by Billy G. Allie.
1100
Guido van Rossum5b08f132001-04-16 02:05:23 +00001101- Updated RISCOS port.
1102
1103- Updated BeOS port and notes.
1104
1105- Various other porting problems resolved.
1106
1107Library
1108
1109- The TERMIOS and SOCKET modules are now truly obsolete and
1110 unnecessary. Their symbols are incorporated in the termios and
1111 socket modules.
1112
1113- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1114 better tests for pickling.
1115
1116- threading: make Condition.wait() robust against KeyboardInterrupt.
1117
1118- zipfile: add support to zipfile to support opening an archive
1119 represented by an open file rather than a file name. Fix bug where
1120 the archive was not properly closed. Fixed a bug in this bugfix
1121 where flush() was called for a read-only file.
1122
1123- imputil: added an uninstall() method to the ImportManager.
1124
1125- Canvas: fixed bugs in lower() and tkraise() methods.
1126
1127- SocketServer: API change (added overridable close_request() method)
1128 so that the TCP server can explicitly close the request.
1129
1130- pstats: Eric Raymond added a simple interactive statistics browser,
1131 invoked when the module is run as a script.
1132
1133- locale: fixed a problem in format().
1134
1135- webbrowser: made it work when the BROWSER environment variable has a
1136 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1137 KDE 2. Fixed some other nits.
1138
1139- unittest: changes to allow using a different exception than
1140 AssertionError, and added a few more function aliases. Some other
1141 small changes.
1142
1143- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1144
1145- asynchat: fixed a critical bug in asynchat that slipped through the
1146 2.1b2 release. Fixed another rare bug.
1147
1148- Fix some unqualified except: clauses (always a bad code example).
1149
1150XML
1151
1152- pyexpat: new API get_version_string().
1153
1154- Fixed some minidom bugs.
1155
1156Extensions
1157
1158- Fixed a core dump in _weakref. Removed the weakref.mapping()
1159 function (it adds nothing to the API).
1160
1161- Rationalized the use of header files in the readline module, to make
1162 it compile (albeit with some warnings) with the very recent readline
1163 4.2, without breaking for earlier versions.
1164
1165- Hopefully fixed a buffering problem in linuxaudiodev.
1166
1167- Attempted a fix to make the OpenSSL support in the socket module
1168 work again with pre-0.9.5 versions of OpenSSL.
1169
1170Tests
1171
1172- Added a test case for asynchat and asyncore.
1173
1174- Removed coupling between tests where one test failing could break
1175 another.
1176
1177Tools
1178
1179- Ping added an interactive help browser to pydoc, fixed some nits
1180 in the rest of the pydoc code, and added some features to his
1181 inspect module.
1182
1183- An updated python-mode.el version 4.1 which integrates Ken
1184 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1185 much nicer in XEmacs and Emacs. When stepping through your program
1186 with pdb, in either the shell window or the *Python* window, the
1187 source file and line will be tracked by an arrow. Very cool!
1188
1189- IDLE: syntax warnings in interactive mode are changed into errors.
1190
1191- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001192 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001193
1194- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001195
Barry Warsaw11e89c72001-04-11 20:37:57 +00001196
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001197What's New in Python 2.1 beta 2?
1198================================
1199
Guido van Rossum053ae352001-03-22 14:17:21 +00001200(Unlisted are many fixed bugs, more documentation, etc.)
1201
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001202Core language, builtins, and interpreter
1203
Guido van Rossum053ae352001-03-22 14:17:21 +00001204- The nested scopes work (enabled by "from __future__ import
1205 nested_scopes") is completed; in particular, the future now extends
1206 into code executed through exec, eval() and execfile(), and into the
1207 interactive interpreter.
1208
1209- When calling a base class method (e.g. BaseClass.__init__(self)),
1210 this is now allowed even if self is not strictly spoken a class
1211 instance (e.g. when using metaclasses or the Don Beaudry hook).
1212
1213- Slice objects are now comparable but not hashable; this prevents
1214 dict[:] from being accepted but meaningless.
1215
1216- Complex division is now calculated using less braindead algorithms.
1217 This doesn't change semantics except it's more likely to give useful
1218 results in extreme cases. Complex repr() now uses full precision
1219 like float repr().
1220
1221- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1222
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001223- It is illegal to assign to the name __debug__, which is set when the
1224 interpreter starts. It is effectively a compile-time constant.
1225
1226- A warning will be issued if a global statement for a variable
1227 follows a use or assignment of that variable.
1228
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001229Standard library
1230
Guido van Rossum053ae352001-03-22 14:17:21 +00001231- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1232 inspired by JUnit), is now part of the standard library. You now
1233 have a choice of two testing frameworks: unittest requires you to
1234 write testcases as separate code, doctest gathers them from
1235 docstrings. Both approaches have their advantages and
1236 disadvantages.
1237
1238- A new module Tix was added, which wraps the Tix extension library
1239 for Tk. With that module, it is not necessary to statically link
1240 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1241 require" command. See Demo/tix/.
1242
1243- tzparse.py is now obsolete.
1244
1245- In gzip.py, the seek() and tell() methods are removed -- they were
1246 non-functional anyway, and it's better if callers can test for their
1247 existence with hasattr().
1248
1249Python/C API
1250
1251- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1252 that's already in the dictionary during a PyDict_Next() iteration.
1253 This used to fail occasionally when a dictionary resize operation
1254 could be triggered that would rehash all the keys. All other
1255 modifications to the dictionary are still off-limits during a
1256 PyDict_Next() iteration!
1257
1258- New extended APIs related to passing compiler variables around.
1259
1260- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1261 implement isinstance() and issubclass().
1262
1263- Py_BuildValue() now has a "D" conversion to create a Python complex
1264 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001265
Fred Drake4e262a92001-03-22 18:26:47 +00001266- Extensions types which support weak references must now set the
1267 field allocated for the weak reference machinery to NULL themselves;
1268 this is done to avoid the cost of checking each object for having a
1269 weakly referencable type in PyObject_INIT(), since most types are
1270 not weakly referencable.
1271
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001272- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1273 free variables and cell variables to and from the frame's f_locals.
1274
1275- Variants of several functions defined in pythonrun.h have been added
1276 to support the nested_scopes future statement. The variants all end
1277 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1278 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1279 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001280 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001281
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001282Distutils
1283
1284- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1285 into the release tree.
1286
Tim Peters0e57abf2001-05-02 07:39:38 +00001287- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001288 (an uninstaller, more customization of the installer's display)
1289
1290- from Jack Jansen: added Mac-specific code to generate a dialog for
1291 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001292 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001293 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001294
1295- added 'platforms' and 'keywords' to the set of metadata that can be
1296 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001297
1298- applied patches from Jason Tishler to make the compiler class work with
1299 Cygwin.
1300
1301
Tim Peters2fe289a2001-03-01 22:19:38 +00001302What's New in Python 2.1 beta 1?
1303================================
Tim Petersd66595f2001-02-04 03:09:53 +00001304
1305Core language, builtins, and interpreter
1306
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001307- Following an outcry from the community about the amount of code
1308 broken by the nested scopes feature introduced in 2.1a2, we decided
1309 to make this feature optional, and to wait until Python 2.2 (or at
1310 least 6 months) to make it standard. The option can be enabled on a
1311 per-module basis by adding "from __future__ import nested_scopes" at
1312 the beginning of a module (before any other statements, but after
1313 comments and an optional docstring). See PEP 236 (Back to the
1314 __future__) for a description of the __future__ statement. PEP 227
1315 (Statically Nested Scopes) has been updated to reflect this change,
1316 and to clarify the semantics in a number of endcases.
1317
1318- The nested scopes code, when enabled, has been hardened, and most
1319 bugs and memory leaks in it have been fixed.
1320
1321- Compile-time warnings are now generated for a number of conditions
1322 that will break or change in meaning when nested scopes are enabled:
1323
1324 - Using "from...import *" or "exec" without in-clause in a function
1325 scope that also defines a lambda or nested function with one or
1326 more free (non-local) variables. The presence of the import* or
1327 bare exec makes it impossible for the compiler to determine the
1328 exact set of local variables in the outer scope, which makes it
1329 impossible to determine the bindings for free variables in the
1330 inner scope. To avoid the warning about import *, change it into
1331 an import of explicitly name object, or move the import* statement
1332 to the global scope; to avoid the warning about bare exec, use
1333 exec...in... (a good idea anyway -- there's a possibility that
1334 bare exec will be deprecated in the future).
1335
1336 - Use of a global variable in a nested scope with the same name as a
1337 local variable in a surrounding scope. This will change in
1338 meaning with nested scopes: the name in the inner scope will
1339 reference the variable in the outer scope rather than the global
1340 of the same name. To avoid the warning, either rename the outer
1341 variable, or use a global statement in the inner function.
1342
Neil Schemenauera35c6882001-02-27 04:45:05 +00001343- An optional object allocator has been included. This allocator is
1344 optimized for Python objects and should be faster and use less memory
1345 than the standard system allocator. It is not enabled by default
1346 because of possible thread safety problems. The allocator is only
1347 protected by the Python interpreter lock and it is possible that some
1348 extension modules require a thread safe allocator. The object
1349 allocator can be enabled by providing the "--with-pymalloc" option to
1350 configure.
1351
Tim Petersd66595f2001-02-04 03:09:53 +00001352Standard library
1353
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001354- pyexpat now detects the expat version if expat.h defines it. A
1355 number of additional handlers are provided, which are only available
1356 since expat 1.95. In addition, the methods SetParamEntityParsing and
1357 GetInputContext of Parser objects are available with 1.95.x
1358 only. Parser objects now provide the ordered_attributes and
1359 specified_attributes attributes. A new module expat.model was added,
1360 which offers a number of additional constants if 1.95.x is used.
1361
1362- xml.dom offers the new functions registerDOMImplementation and
1363 getDOMImplementation.
1364
1365- xml.dom.minidom offers a toprettyxml method. A number of DOM
1366 conformance issues have been resolved. In particular, Element now
1367 has an hasAttributes method, and the handling of namespaces was
1368 improved.
1369
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001370- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1371 getting information about live Python code, and pydoc.py, a module
1372 for interactively converting docstrings to HTML or text.
1373 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001374 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001375 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1376 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001377
Tim Peters1eff7962001-03-01 02:31:33 +00001378- New library module difflib.py, primarily packaging the SequenceMatcher
1379 class at the heart of the popular ndiff.py file-comparison tool.
1380
1381- doctest.py (a framework for verifying Python code examples in docstrings)
1382 is now part of the std library.
1383
Tim Petersd66595f2001-02-04 03:09:53 +00001384Windows changes
1385
Guido van Rossume3955a82001-03-02 14:05:59 +00001386- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1387 small GUI that lets you browse the module docstrings using your
1388 default web browser.
1389
Tim Peters1eff7962001-03-01 02:31:33 +00001390- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1391 Platforms) is implemented. See
1392
1393 http://python.sourceforge.net/peps/pep-0235.html
1394
1395 for full details, especially the "Current Lower-Left Semantics" section.
1396 The new Windows import rules are simpler than before:
1397
1398 A. If the PYTHONCASEOK environment variable exists, same as
1399 before: silently accept the first case-insensitive match of any
1400 kind; raise ImportError if none found.
1401
1402 B. Else search sys.path for the first case-sensitive match; raise
1403 ImportError if none found.
1404
1405 The same rules have been implented on other platforms with case-
1406 insensitive but case-preserving filesystems too (including Cygwin, and
1407 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001408
Tim Peters25a9ce32001-02-19 07:06:36 +00001409- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1410 what it's supposed to do (and does do under NT and 2000) via direct
1411 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001412 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001413 all Win9x systems before.
1414
Tim Peters1eff7962001-03-01 02:31:33 +00001415- Build: Subproject _test (effectively) renamed to _testcapi.
1416
Tim Peters2fe289a2001-03-01 22:19:38 +00001417New platforms
1418
1419- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1420 Thanks to Steven Majewski!
1421
1422- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1423 Tishler!
1424
Guido van Rossum9089b272001-03-02 06:49:50 +00001425- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1426 Schwertberger! See RISCOS/README for more information -- it seems
1427 that because of the bizarre filename conventions on RISCOS, no port
1428 to that platform is easy. Note that the new variable os.endsep is
1429 silently supported in order to make life easier on this platform,
1430 but we don't advertise it because it's not worth for most folks to
1431 care about RISCOS portability.
1432
Tim Peters25a9ce32001-02-19 07:06:36 +00001433
Tim Petersd7b5e882001-01-25 03:36:26 +00001434What's New in Python 2.1 alpha 2?
1435=================================
Tim Peters40ead762001-01-27 05:35:26 +00001436
Tim Petersd7b5e882001-01-25 03:36:26 +00001437Core language, builtins, and interpreter
1438
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001439- Scopes nest. If a name is used in a function or class, but is not
1440 local, the definition in the nearest enclosing function scope will
1441 be used. One consequence of this change is that lambda statements
1442 could reference variables in the namespaces where the lambda is
1443 defined. In some unusual cases, this change will break code.
1444
1445 In all previous version of Python, names were resolved in exactly
1446 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001447 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001448 function A is defined within a function B, the names bound in B are
1449 not visible in A. The new rules make names bound in B visible in A,
1450 unless A contains a name binding that hides the binding in B.
1451
1452 Section 4.1 of the reference manual describes the new scoping rules
1453 in detail. The test script in Lib/test/test_scope.py demonstrates
1454 some of the effects of the change.
1455
1456 The new rules will cause existing code to break if it defines nested
1457 functions where an outer function has local variables with the same
1458 name as globals or builtins used by the inner function. Example:
1459
1460 def munge(str):
1461 def helper(x):
1462 return str(x)
1463 if type(str) != type(''):
1464 str = helper(str)
1465 return str.strip()
1466
1467 Under the old rules, the name str in helper() is bound to the
1468 builtin function str(). Under the new rules, it will be bound to
1469 the argument named str and an error will occur when helper() is
1470 called.
1471
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001472- The compiler will report a SyntaxError if "from ... import *" occurs
1473 in a function or class scope. The language reference has documented
1474 that this case is illegal, but the compiler never checked for it.
1475 The recent introduction of nested scope makes the meaning of this
1476 form of name binding ambiguous. In a future release, the compiler
1477 may allow this form when there is no possibility of ambiguity.
1478
Tim Peters40ead762001-01-27 05:35:26 +00001479- repr(string) is easier to read, now using hex escapes instead of octal,
1480 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1481
1482 >>> "\texample \r\n" + chr(0) + chr(255)
1483 '\texample \r\n\x00\xff' # in 2.1
1484 '\011example \015\012\000\377' # in 2.0
1485
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001486- Functions are now compared and hashed by identity, not by value, since
1487 the func_code attribute is writable.
1488
Fred Drakefb9d7122001-02-01 20:00:40 +00001489- Weak references (PEP 205) have been added. This involves a few
1490 changes in the core, an extension module (_weakref), and a Python
1491 module (weakref). The weakref module is the public interface. It
1492 includes support for "explicit" weak references, proxy objects, and
1493 mappings with weakly held values.
1494
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001495- A 'continue' statement can now appear in a try block within the body
1496 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001497 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001498
Tim Petersd7b5e882001-01-25 03:36:26 +00001499Standard library
1500
Barry Warsaw30dbd142001-01-31 22:14:01 +00001501- mailbox.py now has a new class, PortableUnixMailbox which is
1502 identical to UnixMailbox but uses a more portable scheme for
1503 determining From_ separators. Also, the constructors for all the
1504 classes in this module have a new optional `factory' argument, which
1505 is a callable used when new message classes must be instantiated by
1506 the next() method.
1507
Tim Petersd7b5e882001-01-25 03:36:26 +00001508- random.py is now self-contained, and offers all the functionality of
1509 the now-deprecated whrandom.py. See the docs for details. random.py
1510 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001511 and restoring the internal state of the generator; and jumpahead(n),
1512 for quickly forcing the internal state to be the same as if n calls to
1513 random() had been made. The latter is particularly useful for multi-
1514 threaded programs, creating one instance of the random.Random() class for
1515 each thread, then using .jumpahead() to force each instance to use a
1516 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001517
Tim Peters0de88fc2001-02-01 04:59:18 +00001518- random.py's seed() function is new. For bit-for-bit compatibility with
1519 prior releases, use the whseed function instead. The new seed function
1520 addresses two problems: (1) The old function couldn't produce more than
1521 about 2**24 distinct internal states; the new one about 2**45 (the best
1522 that can be done in the Wichmann-Hill generator). (2) The old function
1523 sometimes produced identical internal states when passed distinct
1524 integers, and there was no simple way to predict when that would happen;
1525 the new one guarantees to produce distinct internal states for all
1526 arguments in [0, 27814431486576L).
1527
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001528- The socket module now supports raw packets on Linux. The socket
1529 family is AF_PACKET.
1530
Tim Peters9ea17ac2001-02-02 05:57:15 +00001531- test_capi.py is a start at running tests of the Python C API. The tests
1532 are implemented by the new Modules/_testmodule.c.
1533
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001534- A new extension module, _symtable, provides provisional access to the
1535 internal symbol table used by the Python compiler. A higher-level
1536 interface will be added on top of _symtable in a future release.
1537
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001538- Removed the obsolete soundex module.
1539
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001540- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1541 the isSameNode method; NamedNodeMap the get method.
1542
1543- xml.sax.expatreader supports the lexical handler property; it
1544 generates comment, startCDATA, and endCDATA events.
1545
Tim Petersee826f82001-01-31 19:39:44 +00001546Windows changes
1547
1548- Build procedure: the zlib project is built in a different way that
1549 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001550 the zlib binary used. See PCbuild\readme.txt for details. Your old
1551 zlib-related directories can be deleted; you'll need to download fresh
1552 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001553
Tim Peters9ea17ac2001-02-02 05:57:15 +00001554- Build: New subproject _test for the benefit of test_capi.py (see above).
1555
Tim Petersb16c56f2001-02-02 21:24:51 +00001556- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1557 interface to some Python compiler internals).
1558
1559- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001560 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001561
Tim Petersa3a3a032000-11-30 05:22:44 +00001562What's New in Python 2.1 alpha 1?
1563=================================
1564
1565Core language, builtins, and interpreter
1566
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001567- There is a new Unicode companion to the PyObject_Str() API
1568 called PyObject_Unicode(). It behaves in the same way as the
1569 former, but assures that the returned value is an Unicode object
1570 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001571
Guido van Rossumf98eda02001-01-17 15:54:45 +00001572- The comparison operators support "rich comparison overloading" (PEP
1573 207). C extension types can provide a rich comparison function in
1574 the new tp_richcompare slot in the type object. The cmp() function
1575 and the C function PyObject_Compare() first try the new rich
1576 comparison operators before trying the old 3-way comparison. There
1577 is also a new C API PyObject_RichCompare() (which also falls back on
1578 the old 3-way comparison, but does not constrain the outcome of the
1579 rich comparison to a Boolean result).
1580
1581 The rich comparison function takes two objects (at least one of
1582 which is guaranteed to have the type that provided the function) and
1583 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1584 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1585 object, which may be NotImplemented (in which case the tp_compare
1586 slot function is used as a fallback, if defined).
1587
1588 Classes can overload individual comparison operators by defining one
1589 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001590 __ge__. There are no explicit "reflected argument" versions of
1591 these; instead, __lt__ and __gt__ are each other's reflection,
1592 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1593 reflection (similar at the C level). No other implications are
1594 made; in particular, Python does not assume that == is the Boolean
1595 inverse of !=, or that < is the Boolean inverse of >=. This makes
1596 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001597
1598 Classes or types that want to implement (in)equality tests but not
1599 the ordering operators (i.e. unordered types) should implement ==
1600 and !=, and raise an error for the ordering operators.
1601
Guido van Rossuma88479f2001-01-18 14:28:08 +00001602 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001603 Boolean; e.g. a matrix type might want to return a matrix of bits
1604 for A < B, giving elementwise comparisons. Such types should ensure
1605 that any interpretation of their value in a Boolean context raises
1606 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1607 at the C level) to always raise an exception.
1608
Guido van Rossuma88479f2001-01-18 14:28:08 +00001609- Complex numbers use rich comparisons to define == and != but raise
1610 an exception for <, <=, > and >=. Unfortunately, this also means
1611 that cmp() of two complex numbers raises an exception when the two
1612 numbers differ. Since it is not mathematically meaningful to compare
1613 complex numbers except for equality, I hope that this doesn't break
1614 too much code.
1615
Tim Peters3389f192001-02-18 08:48:49 +00001616- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001617 not defined by the language, other than that it's arbitrary but
1618 consistent (see the Reference Manual). An implementation detail changed
1619 in 2.1a1 such that None now compares less than any other object. Code
1620 relying on this new behavior (like code that relied on the previous
1621 behavior) does so at its own risk.
1622
Barry Warsaw573b5412001-01-15 20:43:18 +00001623- Functions and methods now support getting and setting arbitrarily
1624 named attributes (PEP 232). Functions have a new __dict__
1625 (a.k.a. func_dict) which hold the function attributes. Methods get
1626 and set attributes on their underlying im_func. It is a TypeError
1627 to set an attribute on a bound method.
1628
Guido van Rossum051e3352001-01-15 19:11:10 +00001629- The xrange() object implementation has been improved so that
1630 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1631 limitation that in this case len(xrange(sys.maxint)) can't be
1632 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1633 work fine as long as the index i doesn't actually reach 2**31.
1634 (Python uses regular ints for sequence and string indices; fixing
1635 that is much more work.)
1636
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001637- Two changes to from...import:
1638
Guido van Rossumba381232001-02-03 15:06:40 +00001639 1) "from M import X" now works even if (after loading module M)
1640 sys.modules['M'] is not a real module; it's basically a getattr()
1641 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001642
1643 2) "from M import *" now looks for M.__all__ to decide which names to
1644 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1645 filters out names starting with '_' as before. Whether or not
1646 __all__ exists, there's no restriction on the type of M.
1647
Guido van Rossumf61f1662001-01-10 20:13:55 +00001648- File objects have a new method, xreadlines(). This is the fastest
1649 way to iterate over all lines in a file:
1650
1651 for line in file.xreadlines():
1652 ...do something to line...
1653
1654 See the xreadlines module (mentioned below) for how to do this for
1655 other file-like objects.
1656
1657- Even if you don't use file.xreadlines(), you may expect a speedup on
1658 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001659 quite a bit in platform-specific ways: on systems (like Linux) that
1660 support flockfile(), getc_unlocked(), and funlockfile(), those are
1661 used by default. On systems (like Windows) without getc_unlocked(),
1662 a complicated (but still thread-safe) method using fgets() is used by
1663 default.
1664
Tim Petersd52269b2001-01-25 06:23:18 +00001665 You can force use of the fgets() method by #define'ing
1666 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001667 getc_unlocked()).
1668
Tim Petersd52269b2001-01-25 06:23:18 +00001669 You can force fgets() not to be used by #define'ing
1670 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001671 test_bufio.py fails -- and let us know if it does!).
1672
1673- In addition, the fileinput module, while still slower than the other
1674 methods on most platforms, has been sped up too, by using
1675 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001676
1677- Support for run-time warnings has been added, including a new
1678 command line option (-W) to specify the disposition of warnings.
1679 See the description of the warnings module below.
1680
1681- Extensive changes have been made to the coercion code. This mostly
1682 affects extension modules (which can now implement mixed-type
1683 numerical operators without having to use coercion), but
1684 occasionally, in boundary cases the coercion semantics have changed
1685 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001686 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001687 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001688 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001689
Guido van Rossumf98eda02001-01-17 15:54:45 +00001690- In connection with the coercion changes, a new built-in singleton
1691 object, NotImplemented is defined. This can be returned for
1692 operations that wish to indicate they are not implemented for a
1693 particular combination of arguments. From C, this is
1694 Py_NotImplemented.
1695
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001696- The interpreter accepts now bytecode files on the command line even
1697 if they do not have a .pyc or .pyo extension. On Linux, after executing
1698
Martin v. Löwise214baa2001-02-04 22:37:56 +00001699import imp,sys,string
1700magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1701reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1702open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001703
1704 any byte code file can be used as an executable (i.e. as an argument
1705 to execve(2)).
1706
Tim Peters9940b802000-12-01 07:59:35 +00001707- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001708 character. In 1.6 and earlier, they never produced a sign,
1709 and raised an error if the value of the long was too large
1710 to fit in a Python int. In 2.0, they produced a sign if and
1711 only if too large to fit in an int. This was inconsistent
1712 across platforms (because the size of an int varies across
1713 platforms), and inconsistent with hex() and oct(). Example:
1714
1715 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001716 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001717 'ffffffbe' # in 2.0 and before, on 32-bit machines
1718 >>> hex(-0x42L)
1719 '-0x42L' # in all versions of Python
1720
Tim Peters9940b802000-12-01 07:59:35 +00001721 The behavior of %d formats for negative Python longs remains
1722 the same as in 2.0 (although in 1.6 and before, they raised
1723 an error if the long didn't fit in a Python int).
1724
1725 %u formats don't make sense for Python longs, but are allowed
1726 and treated the same as %d in 2.1. In 2.0, a negative long
1727 formatted via %u produced a sign if and only if too large to
1728 fit in an int. In 1.6 and earlier, a negative long formatted
1729 via %u raised an error if it was too big to fit in an int.
1730
Guido van Rossum3661d392000-12-12 22:10:31 +00001731- Dictionary objects have an odd new method, popitem(). This removes
1732 an arbitrary item from the dictionary and returns it (in the form of
1733 a (key, value) pair). This can be useful for algorithms that use a
1734 dictionary as a bag of "to do" items and repeatedly need to pick one
1735 item. Such algorithms normally end up running in quadratic time;
1736 using popitem() they can usually be made to run in linear time.
1737
Tim Peters36cdad12000-12-29 02:06:45 +00001738Standard library
1739
Thomas Woutersfe385252001-01-19 23:16:56 +00001740- In the time module, the time argument to the functions strftime,
1741 localtime, gmtime, asctime and ctime is now optional, defaulting to
1742 the current time (in the local timezone).
1743
Guido van Rossumda91f222001-01-15 16:36:08 +00001744- The ftplib module now defaults to passive mode, which is deemed a
1745 more useful default given that clients are often inside firewalls
1746 these days. Note that this could break if ftplib is used to connect
1747 to a *server* that is inside a firewall, from outside; this is
1748 expected to be a very rare situation. To fix that, you can call
1749 ftp.set_pasv(0).
1750
Martin v. Löwis10a27872001-01-13 09:54:41 +00001751- The module site now treats .pth files not only for path configuration,
1752 but also supports extensions to the initialization code: Lines starting
1753 with import are executed.
1754
Guido van Rossumf61f1662001-01-10 20:13:55 +00001755- There's a new module, warnings, which implements a mechanism for
1756 issuing and filtering warnings. There are some new built-in
1757 exceptions that serve as warning categories, and a new command line
1758 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1759 turns warnings into errors). warnings.warn(message[, category])
1760 issues a warning message; this can also be called from C as
1761 PyErr_Warn(category, message).
1762
1763- A new module xreadlines was added. This exports a single factory
1764 function, xreadlines(). The intention is that this code is the
1765 absolutely fastest way to iterate over all lines in an open
1766 file(-like) object:
1767
1768 import xreadlines
1769 for line in xreadlines.xreadlines(file):
1770 ...do something to line...
1771
1772 This is equivalent to the previous the speed record holder using
1773 file.readlines(sizehint). Note that if file is a real file object
1774 (as opposed to a file-like object), this is equivalent:
1775
1776 for line in file.xreadlines():
1777 ...do something to line...
1778
Tim Peters36cdad12000-12-29 02:06:45 +00001779- The bisect module has new functions bisect_left, insort_left,
1780 bisect_right and insort_right. The old names bisect and insort
1781 are now aliases for bisect_right and insort_right. XXX_right
1782 and XXX_left methods differ in what happens when the new element
1783 compares equal to one or more elements already in the list: the
1784 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001785 right. Code that doesn't care where equal elements end up should
1786 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001787
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001788- The new curses.panel module wraps the panel library that forms part
1789 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1790
Guido van Rossumf61f1662001-01-10 20:13:55 +00001791- The SocketServer module now sets the allow_reuse_address flag by
1792 default in the TCPServer class.
1793
1794- A new function, sys._getframe(), returns the stack frame pointer of
1795 the caller. This is intended only as a building block for
1796 higher-level mechanisms such as string interpolation.
1797
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001798- The pyexpat module supports a number of new handlers, which are
1799 available only in expat 1.2. If invocation of a callback fails, it
1800 will report an additional frame in the traceback. Parser objects
1801 participate now in garbage collection. If expat reports an unknown
1802 encoding, pyexpat will try to use a Python codec; that works only
1803 for single-byte charsets. The parser type objects is exposed as
1804 XMLParserObject.
1805
1806- xml.dom now offers standard definitions for symbolic node type and
1807 exception code constants, and a hierarchy of DOM exceptions. minidom
1808 was adjusted to use them.
1809
1810- The conformance of xml.dom.minidom to the DOM specification was
1811 improved. It detects a number of additional error cases; the
1812 previous/next relationship works even when the tree is modified;
1813 Node supports the normalize() method; NamedNodeMap, DocumentType and
1814 DOMImplementation classes were added; Element supports the
1815 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1816 method.
1817
Guido van Rossumf61f1662001-01-10 20:13:55 +00001818Build issues
1819
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001820- For Unix (and Unix-compatible) builds, configuration and building of
1821 extension modules is now greatly automated. Rather than having to
1822 edit the Modules/Setup file to indicate which modules should be
1823 built and where their include files and libraries are, a
1824 distutils-based setup.py script now takes care of building most
1825 extension modules. All extension modules built this way are built
1826 as shared libraries. Only a few modules that must be linked
1827 statically are still listed in the Setup file; you won't need to
1828 edit their configuration.
1829
1830- Python should now build out of the box on Cygwin. If it doesn't,
1831 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001832
1833- Python now always uses its own (renamed) implementation of getopt()
1834 -- there's too much variation among C library getopt()
1835 implementations.
1836
1837- C++ compilers are better supported; the CXX macro is always set to a
1838 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001839
Tim Petersd92dfe02000-12-12 01:18:41 +00001840Windows changes
1841
1842- select module: By default under Windows, a select() call
1843 can specify no more than 64 sockets. Python now boosts
1844 this Microsoft default to 512. If you need even more than
1845 that, see the MS docs (you'll need to #define FD_SETSIZE
1846 and recompile Python from source).
1847
Guido van Rossumf61f1662001-01-10 20:13:55 +00001848- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1849 subdirectory is no more!
1850
Tim Petersa3a3a032000-11-30 05:22:44 +00001851
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001852What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001853=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001854
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001855Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001856changes are in the file HISTORY. If you are making the jump directly
1857from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1858HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001859
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001860Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1861the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1862http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001863
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001864--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001865
1866======================================================================
1867
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001868What's new in 2.0 (since release candidate 1)?
1869==============================================
1870
1871Standard library
1872
1873- The copy_reg module was modified to clarify its intended use: to
1874 register pickle support for extension types, not for classes.
1875 pickle() will raise a TypeError if it is passed a class.
1876
1877- Fixed a bug in gettext's "normalize and expand" code that prevented
1878 it from finding an existing .mo file.
1879
1880- Restored support for HTTP/0.9 servers in httplib.
1881
Tim Peters989b7b92000-10-16 20:24:53 +00001882- The math module was changed to stop raising OverflowError in case of
1883 underflow, and return 0 instead in underflow cases. Whether Python
1884 used to raise OverflowError in case of underflow was platform-
1885 dependent (it did when the platform math library set errno to ERANGE
1886 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001887
1888- Fixed a bug in StringIO that occurred when the file position was not
1889 at the end of the file and write() was called with enough data to
1890 extend past the end of the file.
1891
1892- Fixed a bug that caused Tkinter error messages to get lost on
1893 Windows. The bug was fixed by replacing direct use of
1894 interp->result with Tcl_GetStringResult(interp).
1895
1896- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1897 redirect response.
1898
1899- Several changes were made to distutils: Some debugging code was
1900 removed from util. Fixed the installer used when an external zip
1901 program (like WinZip) is not found; the source code for this
1902 installer is in Misc/distutils. check_lib() was modified to behave
1903 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1904 test for whether installed modules are on sys.path was changed to
1905 use both normcase() and normpath().
1906
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001907- Several minor bugs were fixed in the xml package (the minidom,
1908 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001909
1910- The regression test driver (regrtest.py) behavior when invoked with
1911 -l changed: It now reports a count of objects that are recognized as
1912 garbage but not freed by the garbage collector.
1913
Tim Peters989b7b92000-10-16 20:24:53 +00001914- The regression test for the math module was changed to test
1915 exceptional behavior when the test is run in verbose mode. Python
1916 cannot yet guarantee consistent exception behavior across platforms,
1917 so the exception part of test_math is run only in verbose mode, and
1918 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001919
1920Internals
1921
1922- PyOS_CheckStack() has been disabled on Win64, where it caused
1923 test_sre to fail.
1924
1925Build issues
1926
1927- Changed compiler flags, so that gcc is always invoked with -Wall and
1928 -Wstrict-prototypes. Users compiling Python with GCC should see
1929 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001930 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001931 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001932
Tim Petersa3a3a032000-11-30 05:22:44 +00001933- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001934
1935Tools and other miscellany
1936
1937- The compiler in Tools/compiler was updated to support the new
1938 language features introduced in 2.0: extended print statement, list
1939 comprehensions, and augmented assignments. The new compiler should
1940 also be backwards compatible with Python 1.5.2; the compiler will
1941 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001942 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001943
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001944What's new in 2.0 release candidate 1 (since beta 2)?
1945=====================================================
1946
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001947What is release candidate 1?
1948
1949We believe that release candidate 1 will fix all known bugs that we
1950intend to fix for the 2.0 final release. This release should be a bit
1951more stable than the previous betas. We would like to see even more
1952widespread testing before the final release, so we are producing this
1953release candidate. The final release will be exactly the same unless
1954any show-stopping (or brown bag) bugs are found by testers of the
1955release candidate.
1956
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001957All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001958to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001959
1960Core language, builtins, and interpreter
1961
1962- A bug that caused crashes when __coerce__ was used with augmented
1963 assignment, e.g. +=, was fixed.
1964
1965- Raise ZeroDivisionError when raising zero to a negative number,
1966 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1967 power operator and the result of math.pow(0.0, -2.0) will vary by
1968 platform. On Linux, it raises a ValueError.
1969
1970- A bug in Unicode string interpolation was fixed that occasionally
1971 caused errors with formats including "%%". For example, the
1972 following expression "%% %s" % u"abc" no longer raises a TypeError.
1973
1974- Compilation of deeply nested expressions raises MemoryError instead
1975 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1976
1977- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1978 rendering them useless. They are now written in binary mode again.
1979
1980Standard library
1981
1982- Keyword arguments are now accepted for most pattern and match object
1983 methods in SRE, the standard regular expression engine.
1984
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001985- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001986 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001987
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001988- Several bugs in the Unicode handling and error handling in _tkinter
1989 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001990
1991- Fix memory management errors in Merge() and Tkapp_Call() routines.
1992
1993- Several changes were made to cStringIO to make it compatible with
1994 the file-like object interface and with StringIO. If operations are
1995 performed on a closed object, an exception is raised. The truncate
1996 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001997 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001998
1999- There were many changes made to the linuxaudiodev module and its
2000 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002001 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002002
2003 Note that this module is named poorly, because it should work
2004 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002005 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002006
2007 The module now raises exceptions when errors occur instead of
2008 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2009 audio) and defines a getptr() method that calls the
2010 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2011
2012- The library_version attribute, introduced in an earlier beta, was
2013 removed because it can not be supported with early versions of the C
2014 readline library, which provides no way to determine the version at
2015 compile-time.
2016
2017- The binascii module is now enabled on Win64.
2018
Tim Peters46446d62000-10-09 21:19:31 +00002019- tokenize.py no longer suffers "recursion depth" errors when parsing
2020 programs with very long string literals.
2021
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002022Internals
2023
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002024- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002025 which is called when the interpreter starts up to determine where
2026 the standard library is installed. These vulnerabilities affect all
2027 previous versions of Python and can be exploited by setting very
2028 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2029 setuid Python script, although use of the wrapper in
2030 Misc/setuid-prog.c will eliminate the vulnerability.
2031
2032- Fixed garbage collection bugs in instance creation that were
2033 triggered when errors occurred during initialization. The solution,
2034 applied in cPickle and in PyInstance_New(), is to call
2035 PyObject_GC_Init() after the initialization of the object's
2036 container attributes is complete.
2037
2038- pyexpat adds definitions of PyModule_AddStringConstant and
2039 PyModule_AddObject if the Python version is less than 2.0, which
2040 provides compatibility with PyXML on Python 1.5.2.
2041
2042- If the platform has a bogus definition for LONG_BIT (the number of
2043 bits in a long), an error will be reported at compile time.
2044
2045- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2046 collection crashes and possibly other, unreported crashes.
2047
2048- Fixed a memory leak in _PyUnicode_Fini().
2049
2050Build issues
2051
2052- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002053 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002054 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002055
2056- The mmap.PAGESIZE constant is now initialized using sysconf when
2057 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2058
2059- The md5 file should now compile on all platforms.
2060
2061- The select module now compiles on platforms that do not define
2062 POLLRDNORM and related constants.
2063
2064- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002065 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002066
Jeremy Hylton10921202000-10-09 18:34:12 +00002067- BeOS: A number of changes were made to the build and installation
2068 process. ar-fake now operates on a directory of object files.
2069 dl_export.h is gone, and its macros now appear on the mwcc command
2070 line during build on PPC BeOS.
2071
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002072- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002073 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002074
2075- Cygwin: Support for shared libraries, Tkinter, and sockets.
2076
2077- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2078
2079Tools and other miscellany
2080
2081- Removed debugging prints from main used with freeze.
2082
Tim Peters46446d62000-10-09 21:19:31 +00002083- IDLE auto-indent no longer crashes when it encounters Unicode
2084 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002085
2086What's new in 2.0 beta 2 (since beta 1)?
2087========================================
2088
2089Core language, builtins, and interpreter
2090
Tim Peters482c0212000-09-26 06:33:09 +00002091- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002092 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002093
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002094- Add -h and -V command line options to print the usage message and
2095 Python version number and exit immediately.
2096
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002097- eval() and exec accept Unicode objects as code parameters.
2098
2099- getattr() and setattr() now also accept Unicode objects for the
2100 attribute name, which are converted to strings using the default
2101 encoding before lookup.
2102
2103- Multiplication on string and Unicode now does proper bounds
2104 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2105 string is too long."
2106
2107- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002108 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002109
Jeremy Hylton1b618592000-09-26 05:32:36 +00002110
2111Standard library and extensions
2112
Guido van Rossum5b08f132001-04-16 02:05:23 +00002113- socket module: the OpenSSL code now adds support for RAND_status()
2114 and EGD (Entropy Gathering Device).
2115
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002116- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002117 argument checking; it still takes no arguments.
2118
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002119- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002120
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002121- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002122
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002123- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002124
2125- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002126 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002127
2128- copy: Copy Unicode objects atomically.
2129
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002130- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002131
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002132- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002133
Fred Drake67233bc2000-09-26 16:40:27 +00002134- dbm: Add get() and setdefault() methods to dbm object. Add constant
2135 `library' to module that names the library used. Added doc strings
2136 and method names to error messages. Uses configure to determine
2137 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2138 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002139
2140- distutils: Update to version 0.9.3.
2141
2142- dl: Add several dl.RTLD_ constants.
2143
2144- fpectl: Now supported on FreeBSD.
2145
2146- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2147 found by the collector will be saved in gc.garbage. This is useful
2148 for debugging a program that creates reference cycles.
2149
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002150- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002151 of HTTP class. Do not close socket on zero-length response. Do not
2152 crash when server sends invalid content-length header.
2153
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002154- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002155
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002156- marshal: When reading a short, sign-extend on platforms where shorts
2157 are bigger than 16 bits. When reading a long, repair the unportable
2158 sign extension that was being done for 64-bit machines. (It assumed
2159 that signed right shift sign-extends.)
2160
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002161- operator: Add contains(), invert(), __invert__() as aliases for
2162 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002163
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002164- os: Add support for popen2() and popen3() on all platforms where
2165 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002166
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002167- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002168 clicking on a file in Explorer (or passing the file name to the
2169 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002170
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002171- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002172 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002173
2174- pickle: Now raises ValueError when an invalid pickle that contains
2175 a non-string repr where a string repr was expected. This behavior
2176 matches cPickle.
2177
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002178- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002179
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002180- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002181
2182- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002183 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002184 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002185
2186- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002187 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002188
2189- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002190 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002191 few cycles during startup since the first call to
2192 setdefaultencoding() will initialize the codec registry and the
2193 encodings package.
2194
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002195- socket: Support for size hint in readlines() method of object returned
2196 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002197
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002198- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002199 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002200 is followed by whitespace.
2201
Tim Petersa3a3a032000-11-30 05:22:44 +00002202- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002203
2204- struct: Check ranges for bytes and shorts.
2205
2206- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002207 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002208
2209- Tkinter: Image objects are now guaranteed to have unique ids. Set
2210 event.delta to zero if Tk version doesn't support mousewheel.
2211 Removed some debugging prints.
2212
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002213- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002214
Fred Drake67233bc2000-09-26 16:40:27 +00002215- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002216 which works around a bug in Norton AntiVirus 2000 that leads directly
2217 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002218
2219- xml: New version detection code allows PyXML to override standard
2220 XML package if PyXML version is greater than 0.6.1.
2221
Fred Drake64bb3802000-09-26 16:21:35 +00002222- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2223 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2224 tree only for nodes which are sufficiently interesting to a specific
2225 application. Does not provide the HTML-specific extensions. Still
2226 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002227
Fred Drake64bb3802000-09-26 16:21:35 +00002228- xml.sax: SAX 2 support for Python, including all the handler
2229 interfaces needed to process XML 1.0 compliant XML. Some
2230 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002231
Fred Drake64bb3802000-09-26 16:21:35 +00002232- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2233 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002234
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002235
Jeremy Hylton1b618592000-09-26 05:32:36 +00002236C API
2237
2238- Add three new convenience functions for module initialization --
2239 PyModule_AddObject(), PyModule_AddIntConstant(), and
2240 PyModule_AddStringConstant().
2241
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002242- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002243 removed and add #error to Python.h if NULL isn't defined after
2244 #include of stdio.h.
2245
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002246- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002247 backwards compatibility (at the source level) with old extensions.
2248
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002249- A wrapper API was added for signal() and sigaction(). Instead of
2250 either function, always use PyOS_getsig() to get a signal handler
2251 and PyOS_setsig() to set one. A new convenience typedef
2252 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002253
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002254- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002255 internal data buffer and size of a string object -- or the default
2256 encoded version of a Unicode object.
2257
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002258- PyString_Size() and PyString_AsString() accept Unicode objects.
2259
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002260- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002261 exists). INT_MAX and LONG_MAX will always be defined, even if
2262 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002263
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002264- PyFloat_FromString takes a second argument, pend, that was
2265 effectively useless. It is now officially useless but preserved for
2266 backwards compatibility. If the pend argument is not NULL, *pend is
2267 set to NULL.
2268
2269- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2270 for the attribute name. See note on getattr() above.
2271
2272- A few bug fixes to argument processing for Unicode.
2273 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2274 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2275 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002276 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002277
2278- Py_BuildValue accepts B format (for bgen-generated code).
2279
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002280
Jeremy Hylton1b618592000-09-26 05:32:36 +00002281Internals
2282
2283- On Unix, fix code for finding Python installation directory so that
2284 it works when argv[0] is a relative path.
2285
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002286- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002287 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002288 rather than by generating a copy of the object.
2289
Tim Peters482c0212000-09-26 06:33:09 +00002290- Several of the internal Unicode tables are much smaller now, and
2291 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002292
Jeremy Hylton97693b02000-09-26 17:42:51 +00002293- In the garbage collector: Fixed bug in collection of tuples. Fixed
2294 bug that caused some instances to be removed from the container set
2295 while they were still live. Fixed parsing in gc.set_debug() for
2296 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002297
2298- Fixed refcount problem in instance deallocation that only occurred
2299 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2300
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002301- On Windows, getpythonregpath is now protected against null data in
2302 registry key.
2303
2304- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002305 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002306
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002307
Jeremy Hylton1b618592000-09-26 05:32:36 +00002308Build and platform-specific issues
2309
2310- Better support of GNU Pth via --with-pth configure option.
2311
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002312- Python/C API now properly exposed to dynamically-loaded extension
2313 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002314
2315- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2316 Don't define MS_SYNC to be zero when it is undefined. Added missing
2317 prototypes in posixmodule.c.
2318
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002319- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002320 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002321
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002322- Fix largefile support on older NetBSD systems and OpenBSD by adding
2323 define for TELL64.
2324
2325
2326Tools and other miscellany
2327
2328- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2329
2330- freeze: The modulefinder now works with 2.0 opcodes.
2331
Tim Petersa3a3a032000-11-30 05:22:44 +00002332- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002333 Move hackery of sys.argv until after the Tk instance has been
2334 created, which allows the application-specific Tkinter
2335 initialization to be executed if present; also pass an explicit
2336 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002337
Jeremy Hylton1b618592000-09-26 05:32:36 +00002338
2339What's new in 2.0 beta 1?
2340=========================
2341
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002342Source Incompatibilities
2343------------------------
2344
2345None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2346such as single-argument append(), connect() and bind(), and changes to
2347str(long) and repr(float).
2348
2349
2350Binary Incompatibilities
2351------------------------
2352
2353- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2354with Python 2.0; these extensions will have to be rebuilt for Python
23552.0.
2356
2357- On Windows, attempting to import a third party extension built for
2358Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2359can do about this. Check your PYTHONPATH environment variable!
2360
2361- Python bytecode files (*.pyc and *.pyo) are not compatible between
2362releases.
2363
2364
2365Overview of Changes Since 1.6
2366-----------------------------
2367
2368There are many new modules (including brand new XML support through
2369the xml package, and i18n support through the gettext module); a list
2370of all new modules is included below. Lots of bugs have been fixed.
2371
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002372The process for making major new changes to the language has changed
2373since Python 1.6. Enhancements must now be documented by a Python
2374Enhancement Proposal (PEP) before they can be accepted.
2375
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002376There are several important syntax enhancements, described in more
2377detail below:
2378
2379 - Augmented assignment, e.g. x += 1
2380
2381 - List comprehensions, e.g. [x**2 for x in range(10)]
2382
2383 - Extended import statement, e.g. import Module as Name
2384
2385 - Extended print statement, e.g. print >> file, "Hello"
2386
2387Other important changes:
2388
2389 - Optional collection of cyclical garbage
2390
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002391Python Enhancement Proposal (PEP)
2392---------------------------------
2393
2394PEP stands for Python Enhancement Proposal. A PEP is a design
2395document providing information to the Python community, or describing
2396a new feature for Python. The PEP should provide a concise technical
2397specification of the feature and a rationale for the feature.
2398
2399We intend PEPs to be the primary mechanisms for proposing new
2400features, for collecting community input on an issue, and for
2401documenting the design decisions that have gone into Python. The PEP
2402author is responsible for building consensus within the community and
2403documenting dissenting opinions.
2404
2405The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002406
2407Augmented Assignment
2408--------------------
2409
2410This must have been the most-requested feature of the past years!
2411Eleven new assignment operators were added:
2412
Guido van Rossume905e952000-09-05 12:42:46 +00002413 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002414
2415For example,
2416
2417 A += B
2418
2419is similar to
2420
2421 A = A + B
2422
2423except that A is evaluated only once (relevant when A is something
2424like dict[index].attr).
2425
2426However, if A is a mutable object, A may be modified in place. Thus,
2427if A is a number or a string, A += B has the same effect as A = A+B
2428(except A is only evaluated once); but if a is a list, A += B has the
2429same effect as A.extend(B)!
2430
2431Classes and built-in object types can override the new operators in
2432order to implement the in-place behavior; the not-in-place behavior is
2433used automatically as a fallback when an object doesn't implement the
2434in-place behavior. For classes, the method name is derived from the
2435method name for the corresponding not-in-place operator by inserting
2436an 'i' in front of the name, e.g. __iadd__ implements in-place
2437__add__.
2438
2439Augmented assignment was implemented by Thomas Wouters.
2440
2441
2442List Comprehensions
2443-------------------
2444
2445This is a flexible new notation for lists whose elements are computed
2446from another list (or lists). The simplest form is:
2447
2448 [<expression> for <variable> in <sequence>]
2449
Guido van Rossum56db0952000-09-06 23:34:25 +00002450For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002451This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002452
2453You can also add a condition:
2454
2455 [<expression> for <variable> in <sequence> if <condition>]
2456
2457For example, [w for w in words if w == w.lower()] would yield the list
2458of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002459than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002460
2461You can also have nested for loops and more than one 'if' clause. For
2462example, here's a function that flattens a sequence of sequences::
2463
2464 def flatten(seq):
2465 return [x for subseq in seq for x in subseq]
2466
2467 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2468
2469This prints
2470
2471 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2472
2473List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002474Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002475
2476
2477Extended Import Statement
2478-------------------------
2479
2480Many people have asked for a way to import a module under a different
2481name. This can be accomplished like this:
2482
2483 import foo
2484 bar = foo
2485 del foo
2486
2487but this common idiom gets old quickly. A simple extension of the
2488import statement now allows this to be written as follows:
2489
2490 import foo as bar
2491
2492There's also a variant for 'from ... import':
2493
2494 from foo import bar as spam
2495
2496This also works with packages; e.g. you can write this:
2497
2498 import test.regrtest as regrtest
2499
2500Note that 'as' is not a new keyword -- it is recognized only in this
2501context (this is only possible because the syntax for the import
2502statement doesn't involve expressions).
2503
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002504Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002505
2506
2507Extended Print Statement
2508------------------------
2509
2510Easily the most controversial new feature, this extension to the print
2511statement adds an option to make the output go to a different file
2512than the default sys.stdout.
2513
2514For example, to write an error message to sys.stderr, you can now
2515write:
2516
2517 print >> sys.stderr, "Error: bad dog!"
2518
2519As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002520evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002521
2522 print >> None, "Hello world"
2523
2524is equivalent to
2525
2526 print "Hello world"
2527
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002528Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002529
2530
2531Optional Collection of Cyclical Garbage
2532---------------------------------------
2533
2534Python is now equipped with a garbage collector that can hunt down
2535cyclical references between Python objects. It's no replacement for
2536reference counting; in fact, it depends on the reference counts being
2537correct, and decides that a set of objects belong to a cycle if all
2538their reference counts can be accounted for from their references to
2539each other. This devious scheme was first proposed by Eric Tiedemann,
2540and brought to implementation by Neil Schemenauer.
2541
2542There's a module "gc" that lets you control some parameters of the
2543garbage collection. There's also an option to the configure script
2544that lets you enable or disable the garbage collection. In 2.0b1,
2545it's on by default, so that we (hopefully) can collect decent user
2546experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002547performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002548off by default in the final 2.0 release.
2549
2550
2551Smaller Changes
2552---------------
2553
2554A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2555map(None, seq1, seq2, ...) when the sequences have the same length;
2556i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2557the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002558zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002559
2560sys.version_info is a tuple (major, minor, micro, level, serial).
2561
2562Dictionaries have an odd new method, setdefault(key, default).
2563dict.setdefault(key, default) returns dict[key] if it exists; if not,
2564it sets dict[key] to default and returns that value. Thus:
2565
2566 dict.setdefault(key, []).append(item)
2567
2568does the same work as this common idiom:
2569
2570 if not dict.has_key(key):
2571 dict[key] = []
2572 dict[key].append(item)
2573
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002574There are two new variants of SyntaxError that are raised for
2575indentation-related errors: IndentationError and TabError.
2576
2577Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2578escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002579
2580The limits on the size of expressions and file in Python source code
2581have been raised from 2**16 to 2**32. Previous versions of Python
2582were limited because the maximum argument size the Python VM accepted
2583was 2**16. This limited the size of object constructor expressions,
2584e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2585limit was raised thanks to a patch by Charles Waldman that effectively
2586fixes the problem. It is now much more likely that you will be
2587limited by available memory than by an arbitrary limit in Python.
2588
2589The interpreter's maximum recursion depth can be modified by Python
2590programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2591limit is the maximum number of recursive calls that can be made by
2592Python code. The limit exists to prevent infinite recursion from
2593overflowing the C stack and causing a core dump. The default value is
25941000. The maximum safe value for a particular platform can be found
2595by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002596
2597New Modules and Packages
2598------------------------
2599
2600atexit - for registering functions to be called when Python exits.
2601
2602imputil - Greg Stein's alternative API for writing custom import
2603hooks.
2604
2605pyexpat - an interface to the Expat XML parser, contributed by Paul
2606Prescod.
2607
2608xml - a new package with XML support code organized (so far) in three
2609subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2610would fill a volume. There's a special feature whereby a
2611user-installed package named _xmlplus overrides the standard
2612xmlpackage; this is intended to give the XML SIG a hook to distribute
2613backwards-compatible updates to the standard xml package.
2614
2615webbrowser - a platform-independent API to launch a web browser.
2616
2617
Guido van Rossume905e952000-09-05 12:42:46 +00002618Changed Modules
2619---------------
2620
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002621array -- new methods for array objects: count, extend, index, pop, and
2622remove
2623
2624binascii -- new functions b2a_hex and a2b_hex that convert between
2625binary data and its hex representation
2626
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002627calendar -- Many new functions that support features including control
2628over which day of the week is the first day, returning strings instead
2629of printing them. Also new symbolic constants for days of week,
2630e.g. MONDAY, ..., SUNDAY.
2631
2632cgi -- FieldStorage objects have a getvalue method that works like a
2633dictionary's get method and returns the value attribute of the object.
2634
2635ConfigParser -- The parser object has new methods has_option,
2636remove_section, remove_option, set, and write. They allow the module
2637to be used for writing config files as well as reading them.
2638
2639ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002640optionally support the RFC 959 REST command.
2641
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002642gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002643
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002644httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2645the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002646
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002647locale -- implement getdefaultlocale for Win32 and Macintosh
2648
2649marshal -- no longer dumps core when marshaling deeply nested or
2650recursive data structures
2651
2652os -- new functions isatty, seteuid, setegid, setreuid, setregid
2653
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002654os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2655support under Unix.
2656
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002657os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002658
2659os.path -- fix semantics of os.path.commonprefix
2660
2661smtplib -- support for sending very long messages
2662
2663socket -- new function getfqdn()
2664
2665readline -- new functions to read, write and truncate history files.
2666The readline section of the library reference manual contains an
2667example.
2668
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002669select -- add interface to poll system call
2670
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002671shutil -- new copyfileobj function
2672
2673SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2674HTTP server.
2675
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002676Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002677
2678urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002679e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002680
2681whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002682
2683
2684Obsolete Modules
2685----------------
2686
2687None. However note that 1.6 made a whole slew of modules obsolete:
2688stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2689poly, zmod, strop, util, whatsound.
2690
2691
2692Changed, New, Obsolete Tools
2693----------------------------
2694
Tim Peters8b092332000-09-05 20:15:25 +00002695None.
Guido van Rossume905e952000-09-05 12:42:46 +00002696
2697
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002698C-level Changes
2699---------------
2700
2701Several cleanup jobs were carried out throughout the source code.
2702
2703All C code was converted to ANSI C; we got rid of all uses of the
2704Py_PROTO() macro, which makes the header files a lot more readable.
2705
2706Most of the portability hacks were moved to a new header file,
2707pyport.h; several other new header files were added and some old
2708header files were removed, in an attempt to create a more rational set
2709of header files. (Few of these ever need to be included explicitly;
2710they are all included by Python.h.)
2711
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002712Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002713and Win64, especially for the new Intel Itanium processor. Mick also
2714added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002715
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002716The C APIs to return an object's size have been update to consistently
2717use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2718previous versions, the abstract interfaces used PyXXX_Length and the
2719concrete interfaces used PyXXX_Size. The old names,
2720e.g. PyObject_Length, are still available for backwards compatibility
2721at the API level, but are deprecated.
2722
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002723The PyOS_CheckStack function has been implemented on Windows by
2724Fredrik Lundh. It prevents Python from failing with a stack overflow
2725on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002726
2727The GC changes resulted in creation of two new slots on object,
2728tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002729the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002730
2731The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002732C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002733
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002734PyErr_Format has been updated to automatically calculate the size of
2735the buffer needed to hold the formatted result string. This change
2736prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002737
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002738New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002739
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002740PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2741that are the same as their non-Ex counterparts except they take an
2742extra flag argument that tells them to close the file when done.
2743
2744XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002745
Tim Peters8b092332000-09-05 20:15:25 +00002746
2747Windows Changes
2748---------------
2749
2750New popen2/popen3/peopen4 in os module (see Changed Modules above).
2751
2752os.popen is much more usable on Windows 95 and 98. See Microsoft
2753Knowledge Base article Q150956. The Win9x workaround described there
2754is implemented by the new w9xpopen.exe helper in the root of your
2755Python installation. Note that Python uses this internally; it is not
2756a standalone program.
2757
2758Administrator privileges are no longer required to install Python
2759on Windows NT or Windows 2000. If you have administrator privileges,
2760Python's registry info will be written under HKEY_LOCAL_MACHINE.
2761Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002762under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002763uses of Python, but will prevent some advanced uses from working
2764(for example, running a Python script as an NT service, or possibly
2765from CGI).
2766
2767[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2768installer; instead, it installs the needed Tcl/Tk files directly in the
2769Python directory. If you already have a Tcl/Tk installation, this
2770wastes some disk space (about 4 Megs) but avoids problems with
2771conflicting Tcl/Tk installations, and makes it much easier for Python
2772to ensure that Tcl/Tk can find all its files.
2773
2774[This was new in 1.6] The Windows installer now installs by default in
2775\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2776
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002777
2778Updates to the changes between 1.5.2 and 1.6
2779--------------------------------------------
2780
2781The 1.6 NEWS file can't be changed after the release is done, so here
2782is some late-breaking news:
2783
2784New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2785and changes to getlocale() and setlocale().
2786
2787The new module is now enabled per default.
2788
2789It is not true that the encodings codecs cannot be used for normal
2790strings: the string.encode() (which is also present on 8-bit strings
2791!) allows using them for 8-bit strings too, e.g. to convert files from
2792cp1252 (Windows) to latin-1 or vice-versa.
2793
2794Japanese codecs are available from Tamito KAJIYAMA:
2795http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2796
2797
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002798======================================================================