blob: 83c978c51e31996a2f701b0f2c2d853c343864d6 [file] [log] [blame]
Tim Peters84362bc2001-10-19 17:55:30 +00001What's New in Python 2.2b2?
2XXX Planned XXX Release date: 14-Nov-2001
3===========================
4
5Type/class unification and new-style classes
6
Guido van Rossumc8e56452001-10-22 00:43:43 +00007- Methods of built-in types now properly check for keyword arguments
8 (formerly these were silently ignored). The only built-in methods
9 that take keyword arguments are __call__, __init__ and __new__.
10
Tim Peters84362bc2001-10-19 17:55:30 +000011Core and builtins
12
13Extension modules
14
15Library
16
17Tools/Demos
18
19Build
20
21C API
22
23New platforms
24
25Tests
26
27Windows
28
29
Tim Petersabf925f2001-09-28 21:53:42 +000030What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +000031Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +000032===========================
33
34Type/class unification and new-style classes
35
Guido van Rossum687ae002001-10-15 22:03:32 +000036- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +000037 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +000038 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000039 remains: the __dict__ of a new-style class is a read-only proxy; you
40 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000041 __defined__ attribute of new-style types no longer exists, for lack
42 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000043 future a __cache__ may be resurrected with a similar function, if I
44 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000045
Tim Peters1c9ca872001-10-04 06:43:12 +000046- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
47 always returned None, even when there was a class docstring).
48
49- doctest now finds and runs docstrings attached to new-style classes,
50 class methods, static methods, and properties.
51
Guido van Rossum9074ef62001-10-16 21:34:49 +000052Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +000053
Guido van Rossuma8bcf802001-10-15 15:53:58 +000054- A very subtle syntactical pitfall in list comprehensions was fixed.
55 For example: [a+b for a in 'abc', for b in 'def']. The comma in
56 this example is a mistake. Previously, this would silently let 'a'
57 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
58 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
59 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
60 Note that [a for a in <singleton>] is a convoluted way to say
61 [<singleton>] anyway, so it's not like any expressiveness is lost.
62
Guido van Rossum9074ef62001-10-16 21:34:49 +000063- getattr(obj, name, default) now only catches AttributeError, as
64 documented, rather than returning the default value for all
65 exceptions (which could mask bugs in a __getattr__ hook, for
66 example).
67
Fred Drake934d2a42001-10-18 18:18:06 +000068- Weak reference objects are now part of the core and offers a C API.
69 A bug which could allow a core dump when binary operations involved
Barry Warsawf6fb1712001-10-19 05:35:40 +000070 proxy reference has been fixed. weekref.ReferenceError is now a
71 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +000072
Guido van Rossum1c486092001-10-19 02:05:35 +000073- unicode(obj) now behaves more like str(obj), accepting arbitrary
74 objects, and calling a __unicode__ method if it exists.
75 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +000076 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +000077
Barry Warsawf6fb1712001-10-19 05:35:40 +000078- isinstance() now allows any object as the first argument and a
79 class, a type or something with a __bases__ tuple attribute for the
80 second argument. The second argument may also be a tuple of a
81 class, type, or something with __bases__, in which case isinstance()
82 will return true if the first argument is an instance of any of the
83 things contained in the second argument tuple. E.g.
84
85 isinstance(x, (A, B))
86
87 returns true if x is an instance of A or B.
88
Guido van Rossum9074ef62001-10-16 21:34:49 +000089Extension modules
90
91- thread.start_new_thread() now returns the thread ID (previously None).
92
Martin v. Löwis16dc7f42001-09-30 20:32:11 +000093- binascii has now two quopri support functions, a2b_qp and b2a_qp.
94
Guido van Rossumc524d952001-10-19 01:31:59 +000095- readline now supports setting the startup_hook and the
96 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +000097
Guido van Rossumc524d952001-10-19 01:31:59 +000098- os and posix supports chroot(), setgroups() and unsetenv() where
99 available. The stat(), fstat(), statvfs() and fstatvfs() functions
100 now return "pseudo-sequences" -- the various fields can now be
101 accessed as attributes (e.g. os.stat("/").st_mtime) but for
102 backwards compatibility they also behave as a fixed-length sequence.
103 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000104 attributes.
105
106- time: localtime(), gmtime() and strptime() now return a
107 pseudo-sequence similar to the os.stat() return value, with
108 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000109
Guido van Rossum9074ef62001-10-16 21:34:49 +0000110- Decompression objects in the zlib module now accept an optional
111 second parameter to decompress() that specifies the maximum amount
112 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000113
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000114- optional SSL support in the socket module now exports OpenSSL
115 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
116 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000117 automatically seed its PRNG. Also, the keyfile and certfile
118 arguments to socket.ssl() are now optional.
119
120- posixmodule (and by extension, the os module on POSIX platforms) now
121 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000122
Guido van Rossum9074ef62001-10-16 21:34:49 +0000123Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000124
Tim Peters7402f792001-10-02 03:53:41 +0000125- doctest now excludes functions and classes not defined by the module
126 being tested, thanks to Tim Hochberg.
127
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000128- profile now produces correct output in situations where an exception
129 raised in Python is cleared by C code (e.g. hasattr()). This used
130 to cause wrong output, including spurious claims of recursive
131 functions and attribution of time spent to the wrong function.
132
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000133 The code and documentation for the derived OldProfile and HotProfile
134 profiling classes was removed. The code hasn't worked for years (if
135 you tried to use them, they raised exceptions). OldProfile
136 intended to reproduce the behavior of the profiler Python used more
137 than 7 years ago, and isn't interesting anymore. HotProfile intended
138 to provide a faster profiler (but producing less information), and
139 that's a worthy goal we intend to meet via a different approach (but
140 without losing information).
141
Tim Peterscce092d2001-10-09 05:31:56 +0000142- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000143 a much better system-specific calibration constant. The constant can
144 now be specified in an instance constructor, or as a Profile class or
145 instance variable, instead of by editing profile.py's source code.
146 Calibration must still be done manually (see the docs for the profile
147 module).
148
149 Note that Profile.calibrate() must be overriden by subclasses.
150 Improving the accuracy required exploiting detailed knowledge of
151 profiler internals; the earlier method abstracted away the details
152 and measured a simplified model instead, but consequently computed
153 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000154
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000155- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000156 which indicates whether output is intended for the header 'Q'
157 encoding.
158
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000159- The SocketServer.ThreadingMixIn class now closes the request after
160 finish_request() returns. (Not when it errors out though.)
161
Barry Warsawf6fb1712001-10-19 05:35:40 +0000162- The nntplib module's NNTP.body() method has grown a `file' argument
163 to allow saving the message body to a file.
164
165- The email package has added a class email.Parser.HeaderParser which
166 only parses headers and does not recurse into the message's body.
167 Also, the module/class MIMEAudio has been added for representing
168 audio data (contributed by Anthony Baxter).
169
170- ftplib should be able to handle files > 2GB.
171
172- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
173 ON, and OFF.
174
Guido van Rossumed554f62001-10-02 23:15:37 +0000175Tools/Demos
176
177- Demo/dns was removed. It no longer serves any purpose; a package
178 derived from it is now maintained by Anthony Baxter, see
179 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000180
Barry Warsawf6fb1712001-10-19 05:35:40 +0000181- The freeze tool has been made more robust, and two new options have
182 been added: -X and -E.
183
Tim Petersabf925f2001-09-28 21:53:42 +0000184Build
185
Barry Warsawf6fb1712001-10-19 05:35:40 +0000186- configure will use CXX in LINKCC if CXX is used to build main() and
187 the system requires to link a C++ main using the C++ compiler.
188
Tim Petersabf925f2001-09-28 21:53:42 +0000189C API
190
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000191- The documentation for the tp_compare slot is updated to require that
192 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
193 not correct. This is not yet enforced but will be enforced in
194 Python 2.3; even later, we may use -2 to indicate errors and +2 for
195 "NotImplemented". Right now, -1 should be used for an error return.
196
Tim Petersd38b1c72001-09-30 05:09:37 +0000197- PyLong_AsLongLong() now accepts int (as well as long) arguments.
198 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
199 as long) arguments.
200
Guido van Rossum3c288632001-10-16 21:13:49 +0000201- PyThread_start_new_thread() now returns a long int giving the thread
202 ID, if one can be calculated; it returns -1 for error, 0 if no
203 thread ID is calculated (this is an incompatible change, but only
204 the thread module used this API). This code has only really been
205 tested on Linux and Windows; other platforms please beware (and
206 report any bugs or strange behavior).
207
Guido van Rossum1c486092001-10-19 02:05:35 +0000208- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
209 input.
210
Tim Petersabf925f2001-09-28 21:53:42 +0000211New platforms
212
213Tests
214
215Windows
216
Tim Peters04cf1d32001-10-09 22:39:40 +0000217- Installer: If you install IDLE, and don't disable file-extension
218 registration, a new "Edit with IDLE" context (right-click) menu entry
219 is created for .py and .pyw files.
220
Tim Peters1ce3cf72001-10-01 17:58:40 +0000221- The signal module now supports SIGBREAK on Windows, thanks to Steven
222 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
223 action remains to call Win32 ExitProcess(). This can be changed via
224 signal.signal(). For example:
225
226 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
227 # (SIGINT) behavior.
228 import signal
229 signal.signal(signal.SIGBREAK,
230 signal.default_int_handler)
231
232 try:
233 while 1:
234 pass
235 except KeyboardInterrupt:
236 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
237 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
238 # program without the possibility for any Python-level cleanup).
239 print "Clean exit"
240
Tim Petersabf925f2001-09-28 21:53:42 +0000241
Tim Petersb07352e2001-09-08 01:25:47 +0000242What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000243Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000244===========================
245
Guido van Rossum808eea72001-09-25 04:15:41 +0000246Type/class unification and new-style classes
247
248- pydoc and inspect are now aware of new-style classes;
249 e.g. help(list) at the interactive prompt now shows proper
250 documentation for all operations on list objects.
251
252- Applications using Jim Fulton's ExtensionClass module can now safely
253 be used with Python 2.2. In particular, Zope 2.4.1 now works with
254 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
255 examples also work again. It is hoped that Gtk and Boost also work
256 with 2.2a4 and beyond. (If you can confirm this, please write
257 webmaster@python.org; if there are still problems, please open a bug
258 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000259
Tim Peters66c1a522001-09-24 21:17:50 +0000260- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
261 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
262 in the constructed property object. fget, fset and fdel weren't
263 discoverable from Python in 2.2a3. __doc__ is new, and allows to
264 associate a docstring with a property.
265
Guido van Rossum808eea72001-09-25 04:15:41 +0000266- Comparison overloading is now more completely implemented. For
267 example, a str subclass instance can properly be compared to a str
268 instance, and it can properly overload comparison. Ditto for most
269 other built-in object types.
270
271- The repr() of new-style classes has changed; instead of <type
272 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
273 *except* for built-in types, which are still rendered as <type
274 'Foo'> (to avoid upsetting existing code that might parse or
275 otherwise rely on repr() of certain type objects).
276
277- The repr() of new-style objects is now always <Foo object at XXX>;
278 previously, it was sometimes <Foo instance at XXX>.
279
280- For new-style classes, what was previously called __getattr__ is now
281 called __getattribute__. This method, if defined, is called for
282 *every* attribute access. A new __getattr__ hook mor similar to the
283 one in classic classes is defined which is called only if regular
284 attribute access raises AttributeError; to catch *all* attribute
285 access, you can use __getattribute__ (for new-style classes). If
286 both are defined, __getattribute__ is called first, and if it raises
287 AttributeError, __getattr__ is called.
288
289- The __class__ attribute of new-style objects can be assigned to.
290 The new class must have the same C-level object layout as the old
291 class.
292
293- The builtin file type can be subclassed now. In the usual pattern,
294 "file" is the name of the builtin type, and file() is a new builtin
295 constructor, with the same signature as the builtin open() function.
296 file() is now the preferred way to open a file.
297
298- Previously, __new__ would only see sequential arguments passed to
299 the type in a constructor call; __init__ would see both sequential
300 and keyword arguments. This made no sense whatsoever any more, so
301 now both __new__ and __init__ see all arguments.
302
303- Previously, hash() applied to an instance of a subclass of str or
304 unicode always returned 0. This has been repaired.
305
306- Previously, an operation on an instance of a subclass of an
307 immutable type (int, long, float, complex, tuple, str, unicode),
308 where the subtype didn't override the operation (and so the
309 operation was handled by the builtin type), could return that
310 instance instead a value of the base type. For example, if s was of
311 a str sublass type, s[:] returned s as-is. Now it returns a str
312 with the same value as s.
313
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000314- Provisional support for pickling new-style objects has been added.
315
Guido van Rossum808eea72001-09-25 04:15:41 +0000316Core
317
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000318- file.writelines() now accepts any iterable object producing strings.
319
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000320- PyUnicode_FromEncodedObject() now works very much like
321 PyObject_Str(obj) in that it tries to use __str__/tp_str
322 on the object if the object is not a string or buffer. This
323 makes unicode() behave like str() when applied to non-string/buffer
324 objects.
325
Martin v. Löwis2777c022001-09-19 13:47:32 +0000326- PyFile_WriteObject now passes Unicode object to the file's write
327 method. As a result, all file-like object which may be the target
328 of a print statement must support Unicode objects, i.e. they must
329 at least convert them into ASCII strings.
330
Guido van Rossum624c8af2001-09-18 15:21:04 +0000331- Thread scheduling on Solaris should be improved; it is no longer
332 necessary to insert a small sleep at the start of a thread in order
333 to let other runnable threads be scheduled.
334
Tim Petersb07352e2001-09-08 01:25:47 +0000335Library
336
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000337- StringIO.StringIO instances and cStringIO.StringIO instances support
338 read character buffer compatible objects for their .write() methods.
339 These objects are converted to strings and then handled as such
340 by the instances.
341
Barry Warsaw2f600732001-09-24 04:28:10 +0000342- The "email" package has been added. This is basically a port of the
343 mimelib package <http://sf.net/projects/mimelib> with API changes
344 and some implementations updated to use iterators and generators.
345
Tim Peters8a9c2842001-09-22 21:30:22 +0000346- difflib.ndiff() and difflib.Differ.compare() are generators now. This
347 restores the ability of Tools/scripts/ndiff.py to start producing output
348 before the entire comparison is complete.
349
Barry Warsaw58b072d2001-09-22 04:44:21 +0000350- StringIO.StringIO instances and cStringIO.StringIO instances support
351 iteration just like file objects (i.e. their .readline() method is
352 called for each iteration until it returns an empty string).
353
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000354- The codecs module has grown four new helper APIs to access
355 builtin codecs: getencoder(), getdecoder(), getreader(),
356 getwriter().
357
Guido van Rossum624c8af2001-09-18 15:21:04 +0000358- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
359 simplifies writing XML RPC servers.
360
Barry Warsaw647d5e82001-09-28 17:01:02 +0000361- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000362 after interpretation of symbolic links. On non-Unix systems, this
363 is an alias for os.path.abspath().
364
Tim Peters16a77ad2001-09-08 04:00:12 +0000365- operator.indexOf() (PySequence_Index() in the C API) now works with any
366 iterable object.
367
Guido van Rossum624c8af2001-09-18 15:21:04 +0000368- smtplib now supports various authentication and security features of
369 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000370
Guido van Rossum624c8af2001-09-18 15:21:04 +0000371- hmac: a new module implementing keyed hashing for message
372 authentication.
373
374- mimetypes now recognizes more extensions and file types. At the
375 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000376
Guido van Rossum624c8af2001-09-18 15:21:04 +0000377- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000378 Python 2.2 bytecode generation. It has also been promoted from a
379 Tool to a standard library package. (Tools/compiler still exists as
380 a sample driver.)
381
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000382Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000383
Tim Petersb07352e2001-09-08 01:25:47 +0000384Build
385
Guido van Rossum624c8af2001-09-18 15:21:04 +0000386- Large file support (LFS) is now automatic when the platform supports
387 it; no more manual configuration tweaks are needed. On Linux, at
388 least, it's possible to have a system whose C library supports large
389 files but whose kernel doesn't; in this case, large file support is
390 still enabled but doesn't do you any good unless you upgrade your
391 kernel or share your Python executable with another system whose
392 kernel has large file support.
393
394- The configure script now supplies plausible defaults in a
395 cross-compilation environment. This doesn't mean that the supplied
396 values are always correct, or that cross-compilation now works
397 flawlessly -- but it's a first step (and it shuts up most of
398 autoconf's warnings about AC_TRY_RUN).
399
400- The Unix build is now a bit less chatty, courtesy of the parser
401 generator. The build is completely silent (except for errors) when
402 using "make -s", thanks to a -q option to setup.py.
403
Tim Petersb07352e2001-09-08 01:25:47 +0000404C API
405
Guido van Rossum624c8af2001-09-18 15:21:04 +0000406- The "structmember" API now supports some new flag bits to deny read
407 and/or write access to attributes in restricted execution mode.
408
Tim Petersb07352e2001-09-08 01:25:47 +0000409New platforms
410
Guido van Rossum624c8af2001-09-18 15:21:04 +0000411- Compaq's iPAQ handheld, running the "familiar" Linux distribution
412 (http://familiar.handhelds.org).
413
Tim Petersb07352e2001-09-08 01:25:47 +0000414Tests
415
Tim Peters8a9c2842001-09-22 21:30:22 +0000416- The "classic" standard tests, which work by comparing stdout to
417 an expected-output file under Lib/test/output/, no longer stop at
418 the first mismatch. Instead the test is run to completion, and a
419 variant of ndiff-style comparison is used to report all differences.
420 This is much easier to understand than the previous style of reporting.
421
422- The unittest-based standard tests now use regrtest's test_main()
423 convention, instead of running as a side-effect of merely being
424 imported. This allows these tests to be run in more natural and
425 flexible ways as unittests, outside the regrtest framework.
426
427- regrtest.py is much better integrated with unittest and doctest now,
428 especially in regard to reporting errors.
429
Tim Petersb07352e2001-09-08 01:25:47 +0000430Windows
431
Guido van Rossum624c8af2001-09-18 15:21:04 +0000432- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000433 that support it (NTFS under Windows 2000). See "What's New in
434 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000435
Tim Petersb07352e2001-09-08 01:25:47 +0000436
Tim Petersedc99312001-08-22 21:36:50 +0000437What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000438Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000439===========================
440
441Core
442
Tim Peters9fffa3e2001-09-04 05:14:19 +0000443- Conversion of long to float now raises OverflowError if the long is too
444 big to represent as a C double.
445
Tim Peters32f453e2001-09-03 08:35:41 +0000446- The 3-argument builtin pow() no longer allows a third non-None argument
447 if either of the first two arguments is a float, or if both are of
448 integer types and the second argument is negative (in which latter case
449 the arguments are converted to float, so this is really the same
450 restriction).
451
Tim Peters5d2b77c2001-09-03 05:47:38 +0000452- The builtin dir() now returns more information, and sometimes much
453 more, generally naming all attributes of an object, and all attributes
454 reachable from the object via its class, and from its class's base
455 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
456 an empty list. In 2.2a3,
457
458 >>> dir([])
459 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
460 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
461 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
462 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
463 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
464 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
465 'reverse', 'sort']
466
467 dir(module) continues to return only the module's attributes, though.
468
Tim Petersbdee63f2001-09-02 03:40:59 +0000469- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000470 than raising OverflowError. This is a partial implementation of PEP
471 237. You can use -Wdefault::OverflowWarning to enable a warning for
472 this situation, and -Werror::OverflowWarning to revert to the old
473 OverflowError exception.
474
Guido van Rossum61c345f2001-09-04 03:26:15 +0000475- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000476 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000477 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
478 -Qold, meaning the / operator has its classic meaning and no
479 warnings are issued. Using -Qwarn issues a run-time warning about
480 all uses of classic division for int and long arguments; -Qwarnall
481 also warns about classic division for float and complex arguments
482 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
483 new division by default, but only in the __main__ module. You can
484 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
485 __main__ module new division, and warns about classic division
486 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000487
Tim Petersbdee63f2001-09-02 03:40:59 +0000488- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000489 long, float, str, unicode, and tuple. (The types complex, list and
490 dictionary can also be subclassed; this was introduced earlier.)
491 Note that restrictions apply when subclassing immutable built-in
492 types: you can only affect the value of the instance by overloading
493 __new__. You can add mutable attributes, and the subclass instances
494 will have a __dict__ attribute, but you cannot change the "value"
495 (as implemented by the base class) of an immutable subclass instance
496 once it is created.
497
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000498- The dictionary constructor now takes an optional argument, a
499 mapping-like object, and initializes the dictionary from its
500 (key, value) pairs.
501
Tim Petersbdee63f2001-09-02 03:40:59 +0000502- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000503 "cooperative super calls" in a multiple inheritance setting. For an
504 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
505
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000506- A new built-in type, property, has been added. This enables the
507 creation of "properties". These are attributes implemented by
508 getter and setter functions (or only one of these for read-only or
509 write-only attributes), without the need to override __getattr__.
510 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000511
Tim Petersbdee63f2001-09-02 03:40:59 +0000512- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000513 liberalized, to allow leading zeroes. Examples of literals now
514 legal that were SyntaxErrors before:
515
516 00.0 0e3 0100j 07.5 00000000000000000008.
517
Tim Petersbdee63f2001-09-02 03:40:59 +0000518- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000519 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
520
Tim Petersedc99312001-08-22 21:36:50 +0000521Library
522
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000523- telnetlib includes symbolic names for the options, and support for
524 setting an option negotiation callback.
525
Tim Petersa40c7932001-09-05 22:36:56 +0000526- The new C standard no longer requires that math libraries set errno to
527 ERANGE on overflow. For platform libraries that exploit this new
528 freedom, Python's overflow-checking was wholly broken. A new overflow-
529 checking scheme attempts to repair that, but may not be reliable on all
530 platforms (C doesn't seem to provide anything both useful and portable
531 in this area anymore).
532
Martin v. Löwis44f86962001-09-05 13:44:54 +0000533- Asynchronous timeout actions are available through the new class
534 threading.Timer.
535
Tim Peters78526162001-09-05 00:53:45 +0000536- math.log and math.log10 now return sensible results for even huge
537 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
538
Tim Petersbdee63f2001-09-02 03:40:59 +0000539- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000540 currently held. See the docs for the imp module.
541
Tim Petersbdee63f2001-09-02 03:40:59 +0000542- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000543 dumps containing ints written on platforms where Python ints are 8 bytes.
544 When read on a box where Python ints are 4 bytes, such values are
545 converted to Python longs.
546
Tim Petersbdee63f2001-09-02 03:40:59 +0000547- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000548 code objects is no longer allowed. This plugs a security hole.
549
Steve Purcell6091cd62001-09-06 16:05:17 +0000550- unittest.TestResult instances no longer store references to tracebacks
551 generated by test failures. This prevents unexpected dangling references
552 to objects that should be garbage collected between tests.
553
Tim Petersedc99312001-08-22 21:36:50 +0000554Tools
555
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000556- Tools/scripts/fixdiv.py has been added which can be used to fix
557 division operators as per PEP 238.
558
Tim Petersedc99312001-08-22 21:36:50 +0000559Build
560
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000561- If you are an adventurous person using Mac OS X you may want to look at
562 Mac/OSX. There is a Makefile there that will build Python as a real Mac
563 application, which can be used for experimenting with Carbon or Cocoa.
564 Discussion of this on pythonmac-sig, please.
565
Tim Peters7eea37e2001-09-04 22:08:56 +0000566C API
567
568- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000569
Tim Peters9fffa3e2001-09-04 05:14:19 +0000570- Note that PyLong_AsDouble can fail! This has always been true, but no
571 callers checked for it. It's more likely to fail now, because overflow
572 errors are properly detected now. The proper way to check:
573
574 double x = PyLong_AsDouble(some_long_object);
575 if (x == -1.0 && PyErr_Occurred()) {
576 /* The conversion failed. */
577 }
578
Tim Petersbdee63f2001-09-02 03:40:59 +0000579- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000580 compile but will not participate in GC. To upgrade an extension
581 module:
582
583 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000584
Neil Schemenauer4042c692001-08-30 15:38:01 +0000585 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
586 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000587
Neil Schemenauer4042c692001-08-30 15:38:01 +0000588 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
589 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000590
Neil Schemenauer4042c692001-08-30 15:38:01 +0000591 - remove PyGC_HEAD_SIZE from object size calculations
592
593 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
594
Tim Petersbdee63f2001-09-02 03:40:59 +0000595- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000596 These can be used safely to construct string objects from a
597 sprintf-style format string (similar to the format string supported
598 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000599
Tim Petersedc99312001-08-22 21:36:50 +0000600New platforms
601
Tim Petersb7da0902001-09-02 23:01:43 +0000602- Stephen Hansen contributed patches sufficient to get a clean compile
603 under Borland C (Windows), but he reports problems running it and ran
604 out of time to complete the port. Volunteers? Expect a MemoryError
605 when importing the types module; this is probably shallow, and
606 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000607
Tim Petersedc99312001-08-22 21:36:50 +0000608Tests
609
610Windows
611
Tim Peters6e13a562001-09-06 00:32:15 +0000612- Large file support is now enabled on Win32 platforms as well as on
613 Win64. This means that, for example, you can use f.tell() and f.seek()
614 to manipulate files larger than 2 gigabytes (provided you have enough
615 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000616 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
617 filesize limit, and large file support makes no difference there.
618 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
619 NTFS has no practical limit on file size, and files of any size can be
620 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000621
Tim Petersbdee63f2001-09-02 03:40:59 +0000622- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000623 points to command.com (patch from Brian Quinlan).
624
Tim Petersedc99312001-08-22 21:36:50 +0000625
Tim Peters20f51a72001-07-21 02:31:40 +0000626What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000627Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000628===========================
629
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000630Build
631
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000632- Tim Peters developed a brand new Windows installer using Wise 8.1,
633 generously donated to us by Wise Solutions.
634
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000635- configure supports a new option --enable-unicode, with the values
636 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
637 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000638
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000639- A new configure option --enable-framework builds a Mac OS X framework,
640 which "make frameworkinstall" will install. This provides a starting
641 point for more mac-like functionality, join pythonmac-sig@python.org
642 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000643
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000644- The NeXT platform is no longer supported.
645
646- The `new' module is now statically linked.
647
Tim Peters0afb6092001-08-15 06:06:44 +0000648Tools
649
650- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000651 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000652 the module docstring for details.
653
Tim Peters20f51a72001-07-21 02:31:40 +0000654Tests
655
Tim Peters5e824c32001-08-12 22:25:01 +0000656- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000657 platforms, allowing to give clearer test result output. regrtest
658 also has optional --use/-u switch to run normally disabled tests
659 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000660
Tim Peters20f51a72001-07-21 02:31:40 +0000661- Several new tests in the standard test suite, with special thanks to
662 Nick Mathewson.
663
664Core
665
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000666- The floor division operator // has been added as outlined in PEP
667 238. The / operator still provides classic division (and will until
668 Python 3.0) unless "from __future__ import division" is included, in
669 which case the / operator will provide true division. The operator
670 module provides truediv() and floordiv() functions. Augmented
671 assignment variants are included, as are the equivalent overloadable
672 methods and C API methods. See the PEP for a full discussion:
673 <http://python.sf.net/peps/pep-0238.html>
674
Tim Peters6cd6a822001-08-17 22:11:27 +0000675- Future statements are now effective in simulated interactive shells
676 (like IDLE). This should "just work" by magic, but read Michael
677 Hudson's "Future statements in simulated shells" PEP 264 for full
678 details: <http://python.sf.net/peps/pep-0264.html>.
679
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000680- The type/class unification (PEP 252-253) was integrated into the
681 trunk and is not so tentative any more (the exact specification of
682 some features is still tentative). A lot of work has done on fixing
683 bugs and adding robustness and features (performance still has to
684 come a long way).
685
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000686- Warnings about a mismatch in the Python API during extension import
687 now use the Python warning framework (which makes it possible to
688 write filters for these warnings).
689
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000690- A function's __dict__ (aka func_dict) will now always be a
691 dictionary. It used to be possible to delete it or set it to None,
692 but now both actions raise TypeErrors. It is still legal to set it
693 to a dictionary object. Getting func.__dict__ before any attributes
694 have been assigned now returns an empty dictionary instead of None.
695
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000696- A new command line option, -E, was added which disables the use of
697 all environment variables, or at least those that are specifically
698 significant to Python. Usually those have a name starting with
699 "PYTHON". This was used to fix a problem where the tests fail if
700 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
701 older distribution.
702
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000703Library
704
Tim Peters5e824c32001-08-12 22:25:01 +0000705- New class Differ and new functions ndiff() and restore() in difflib.py.
706 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000707 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000708
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000709- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
710 value using the minimal quoting required for the value; more
711 reliable than using xml.sax.saxutils.escape() for attribute values.
712
713- Readline completion support for cmd.Cmd was added.
714
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000715- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
716
717- Added function threading.BoundedSemaphore()
718
719- Added Ka-Ping Yee's cgitb.py module.
720
721- The `new' module now exposes the CO_xxx flags.
722
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000723New platforms
724
725C API
726
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000727- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
728 which provide a cross-platform implementations for the
729 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
730 the standard sprintf() and vsprintf() C lib APIs, these versions
731 apply bounds checking on the used buffer which enhances protection
732 against buffer overruns.
733
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000734- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000735 and extensions using different Unicode widths is rendered next to
736 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000737 will result in an ImportError. Unicode extensions writers must make
738 sure to check the Unicode width compatibility in their extensions by
739 using at least one of the mangled Unicode APIs in the extension.
740
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000741- Two new flags METH_NOARGS and METH_O are available in method definition
742 tables to simplify implementation of methods with no arguments and a
743 single untyped argument. Calling such methods is more efficient than
744 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
745 deprecated.
746
Tim Petersc1731372001-08-04 08:12:36 +0000747Windows
748
749- "import module" now compiles module.pyw if it exists and nothing else
750 relevant is found.
751
Tim Peters20f51a72001-07-21 02:31:40 +0000752
Guido van Rossum55a78992001-07-17 17:22:32 +0000753What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000754===========================
755
756Core
Tim Petersa814db52001-05-14 07:05:58 +0000757
Tim Peters6d6c1a32001-08-02 04:15:00 +0000758- TENTATIVELY, a large amount of code implementing much of what's
759 described in PEP 252 (Making Types Look More Like Classes) and PEP
760 253 (Subtyping Built-in Types) was added. This will be released
761 with Python 2.2a1. Documentation will be provided separately
762 through http://www.python.org/2.2/. The purpose of releasing this
763 with Python 2.2a1 is to test backwards compatibility. It is
764 possible, though not likely, that a decision is made not to release
765 this code as part of 2.2 final, if any serious backwards
766 incompapatibilities are found during alpha testing that cannot be
767 repaired.
768
Guido van Rossum55a78992001-07-17 17:22:32 +0000769- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000770 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000771 more 'yield' statements. See PEP 255. Since this adds a new
772 keyword to the language, this feature must be enabled by including a
773 future statement: "from __future__ import generators" (see PEP 236).
774 Generators will become a standard feature in a future release
775 (probably 2.3). Without this future statement, 'yield' remains an
776 ordinary identifier, but a warning is issued each time it is used.
777 (These warnings currently don't conform to the warnings framework of
778 PEP 230; we intend to fix this in 2.2a2.)
779
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000780- The UTF-16 codec was modified to be more RFC compliant. It will now
781 only remove BOM characters at the start of the string and then
782 only if running in native mode (UTF-16-LE and -BE won't remove a
783 leading BMO character).
784
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000785- Strings now have a new method .decode() to complement the already
786 existing .encode() method. These two methods provide direct access
787 to the corresponding decoders and encoders of the registered codecs.
788
789 To enhance the usability of the .encode() method, the special
790 casing of Unicode object return values was dropped (Unicode objects
791 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000792
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000793 Both methods will now return whatever the codec in charge of the
794 requested encoding returns as object, e.g. Unicode codecs will
795 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
796 will return u"äöü"). This enables codec writer to create codecs
797 for various simple to use conversions.
798
799 New codecs were added to demonstrate these new features (the .encode()
800 and .decode() columns indicate the type of the returned objects):
801
802 Name | .encode() | .decode() | Description
803 ----------------------------------------------------------------------
804 uu | string | string | UU codec (e.g. for email)
805 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000806 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000807 zlib | string | string | zlib compression
808 hex | string | string | 2-byte hex codec
809 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
810
Mark Hammond2a0af792001-05-14 03:09:36 +0000811- Some operating systems now support the concept of a default Unicode
812 encoding for file system operations. Notably, Windows supports 'mbcs'
813 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000814 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000815 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000816
817 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000818 functions that return filenames (such as os.listdir()) to return Python
819 string objects pre-encoded using the default file system encoding for
820 the platform. As this encoding is likely to be different from Python's
821 default encoding, converting this name to a Unicode object before passing
822 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000823 would attempt to use its default encoding (generally ASCII) rather than
824 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000825
Tim Petersa814db52001-05-14 07:05:58 +0000826 In general, this change simply removes surprises when working with
827 Unicode and the file system, making these operations work as you expect,
828 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000829 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000830
Tim Peters61dff2b2001-05-08 15:43:37 +0000831- Float (and complex) literals in source code were evaluated to full
832 precision only when running from a .py file; the same code loaded from a
833 .pyc (or .pyo) file could suffer numeric differences starting at about the
834 12th significant decimal digit. For example, on a machine with IEEE-754
835 floating arithmetic,
836
837 x = 9007199254740992.0
838 print long(x)
839
840 printed 9007199254740992 if run directly from .py, but 9007199254740000
841 if from a compiled (.pyc or .pyo) file. This was due to marshal using
842 str(float) instead of repr(float) when building code objects. marshal
843 now uses repr(float) instead, which should reproduce floats to full
844 machine precision (assuming the platform C float<->string I/O conversion
845 functions are of good quality).
846
847 This may cause floating-point results to change in some cases, and
848 usually for the better, but may also cause numerically unstable
849 algorithms to break.
850
Tim Peters2f228e72001-05-13 00:19:31 +0000851- The implementation of dicts suffers fewer collisions, which has speed
852 benefits. However, the order in which dict entries appear in dict.keys(),
853 dict.values() and dict.items() may differ from previous releases for a
854 given dict. Nothing is defined about this order, so no program should
855 rely on it. Nevertheless, it's easy to write test cases that rely on the
856 order by accident, typically because of printing the str() or repr() of a
857 dict to an "expected results" file. See Lib/test/test_support.py's new
858 sortdict(dict) function for a simple way to display a dict in sorted
859 order.
860
Tim Peters7a3bfc32001-06-12 01:22:22 +0000861- Many other small changes to dicts were made, resulting in faster
862 operation along the most common code paths.
863
Guido van Rossum10315822001-05-01 20:54:30 +0000864- Dictionary objects now support the "in" operator: "x in dict" means
865 the same as dict.has_key(x).
866
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000867- The update() method of dictionaries now accepts generic mapping
868 objects. Specifically the argument object must support the .keys()
869 and __getitem__() methods. This allows you to say, for example,
870 {}.update(UserDict())
871
Guido van Rossum10315822001-05-01 20:54:30 +0000872- Iterators were added; this is a generalized way of providing values
873 to a for loop. See PEP 234. There's a new built-in function iter()
874 to return an iterator. There's a new protocol to get the next value
875 from an iterator using the next() method (in Python) or the
876 tp_iternext slot (in C). There's a new protocol to get iterators
877 using the __iter__() method (in Python) or the tp_iter slot (in C).
878 Iterating (i.e. a for loop) over a dictionary generates its keys.
879 Iterating over a file generates its lines.
880
Tim Petersf553f892001-05-01 20:45:31 +0000881- The following functions were generalized to work nicely with iterator
882 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000883 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000884 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
885 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000886 join() method of strings
887 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000888 'x in y' and 'x not in y' (PySequence_Contains() in C API)
889 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000890 right-hand side of assignment statements with multiple targets, such as
891 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000892
Tim Petersd85e1022001-05-11 21:51:48 +0000893- Accessing module attributes is significantly faster (for example,
894 random.random or os.path or yourPythonModule.yourAttribute).
895
Tim Peterse63415e2001-05-08 04:38:29 +0000896- Comparing dictionary objects via == and != is faster, and now works even
897 if the keys and values don't support comparisons other than ==.
898
Tim Peters95bf9392001-05-10 08:32:44 +0000899- Comparing dictionaries in ways other than == and != is slower: there were
900 insecurities in the dict comparison implementation that could cause Python
901 to crash if the element comparison routines for the dict keys and/or
902 values mutated the dicts. Making the code bulletproof slowed it down.
903
Tim Peterseb28ef22001-06-02 05:27:19 +0000904- Collisions in dicts are resolved via a new approach, which can help
905 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000906 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000907 faster now. Thanks to Christian Tismer for pointing out the cause and
908 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000909
Tim Peters52e155e2001-06-16 05:42:57 +0000910- repr() is much faster for large containers (dict, list, tuple).
911
912
Tim Petersa814db52001-05-14 07:05:58 +0000913Library
914
Fred Drake960fdf92001-07-20 18:38:26 +0000915- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
916 were added to the string module. These a locale-indenpendent
917 constants, unlike letters, lowercase, and uppercase. These are now
918 use in appropriate locations in the standard library.
919
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000920- The flags used in dlopen calls can now be configured using
921 sys.setdlopenflags and queried using sys.getdlopenflags.
922
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000923- Fredrik Lundh's xmlrpclib is now a standard library module. This
924 provides full client-side XML-RPC support. In addition,
925 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
926 one asyncore-based). Thanks to Eric Raymond for the documentation.
927
Guido van Rossum643d3912001-07-05 14:46:25 +0000928- The xrange() object is simplified: it no longer supports slicing,
929 repetition, comparisons, efficient 'in' checking, the tolist()
930 method, or the start, stop and step attributes. See PEP 260.
931
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000932- A new function fnmatch.filter to filter lists of file names was added.
933
Barry Warsawffd674d2001-05-22 16:00:10 +0000934- calendar.py uses month and day names based on the current locale.
935
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000936- strop is now *really* obsolete (this was announced before with 1.6),
937 and issues DeprecationWarning when used (except for the four items
938 that are still imported into string.py).
939
Tim Petersa814db52001-05-14 07:05:58 +0000940- Cookie.py now sorts key+value pairs by key in output strings.
941
942- pprint.isrecursive(object) didn't correctly identify recursive objects.
943 Now it does.
944
Tim Peters95b3f782001-05-14 18:39:41 +0000945- pprint functions now much faster for large containers (tuple, list, dict).
946
Tim Peters7b9542a2001-06-10 23:40:19 +0000947- New 'q' and 'Q' format codes in the struct module, corresponding to C
948 types "long long" and "unsigned long long" (on Windows, __int64). In
949 native mode, these can be used only when the platform C compiler supports
950 these types (when HAVE_LONG_LONG is #define'd by the Python config
951 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000952 In standard mode, 'q' and 'Q' are supported on all platforms, and are
953 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000954
Guido van Rossum83213cc2001-06-12 16:48:52 +0000955- The site module installs a new built-in function 'help' that invokes
956 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
957 it displays a message reminding the user to use 'help()' or
958 'help(object)'.
959
Tim Petersa814db52001-05-14 07:05:58 +0000960Tests
961
962- New test_mutants.py runs dict comparisons where the key and value
963 comparison operators mutute the dicts randomly during comparison. This
964 rapidly causes Python to crash under earlier releases (not for the faint
965 of heart: it can also cause Win9x to freeze or reboot!).
966
967- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000968 pprint.isreadable() return sensible results. Also verifies that simple
969 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000970
Tim Peters4324aa32001-05-28 22:30:08 +0000971C API
972
973- Removed the unused last_is_sticky argument from the internal
974 _PyTuple_Resize(). If this affects you, you were cheating.
975
976
Guido van Rossum55a78992001-07-17 17:22:32 +0000977======================================================================
978
979
Guido van Rossumffe13be2001-04-16 18:46:45 +0000980What's New in Python 2.1 (final)?
981=================================
982
983We only changed a few things since the last release candidate, all in
984Python library code:
985
986- A bug in the locale module was fixed that affected locales which
987 define no grouping for numeric formatting.
988
989- A few bugs in the weakref module's implementations of weak
990 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
991 and the test suite was updated to check for these bugs.
992
993- An old bug in the os.path.walk() function (introduced in Python
994 2.0!) was fixed: a non-existent file would cause an exception
995 instead of being ignored.
996
997- Fixed a few bugs in the new symtable module found by Neil Norwitz's
998 PyChecker.
999
1000
Guido van Rossum5b08f132001-04-16 02:05:23 +00001001What's New in Python 2.1c2?
1002===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001003
Guido van Rossum5b08f132001-04-16 02:05:23 +00001004A flurry of small changes, and one showstopper fixed in the nick of
1005time made it necessary to release another release candidate. The list
1006here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001007
Guido van Rossum5b08f132001-04-16 02:05:23 +00001008Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001009
Guido van Rossum5b08f132001-04-16 02:05:23 +00001010- Tim discovered a nasty bug in the dictionary code, caused by
1011 PyDict_Next() calling dict_resize(), and the GC code's use of
1012 PyDict_Next() violating an assumption in dict_items(). This was
1013 fixed with considerable amounts of band-aid, but the net effect is a
1014 saner and more robust implementation.
1015
1016- Made a bunch of symbols static that were accidentally global.
1017
1018Build and Ports
1019
1020- The setup.py script didn't check for a new enough version of zlib
1021 (1.1.3 is needed). Now it does.
1022
1023- Changed "make clean" target to also remove shared libraries.
1024
1025- Added a more general warning about the SGI Irix optimizer to README.
1026
1027Library
1028
1029- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1030 omitted the slash between host and file.html.
1031
1032- The mailbox module's _Mailbox class contained a completely broken
1033 and undocumented seek() method. Ripped it out.
1034
1035- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1036 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1037
1038- Fixed a few last-minute bugs in unittest.
1039
1040Extensions
1041
1042- Reverted the patch to the OpenSSL code in socketmodule.c to support
1043 RAND_status() and the EGD, and the subsequent patch that tried to
1044 fix it for pre-0.9.5 versions; the problem with the patch is that on
1045 some systems it issues a warning whenever socket is imported, and
1046 that's unacceptable.
1047
1048Tests
1049
1050- Fixed the pickle tests to work with "import test.test_pickle".
1051
1052- Tweaked test_locale.py to actually run the test Windows.
1053
1054- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1055 not "wb" (which is not a valid mode at all).
1056
1057- Fix pstats browser crashes. Import readline if it exists to make
1058 the user interface nicer.
1059
1060- Add "import thread" to the top of test modules that import the
1061 threading module (test_asynchat and test_threadedtempfile). This
1062 prevents test failures caused by a broken threading module resulting
1063 from a previously caught failed import.
1064
1065- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1066 needed on some platforms (e.g. Solaris 8) when the tests are run
1067 twice in succession.
1068
1069- Skip rather than fail test_sunaudiodev if no audio device is found.
1070
1071
1072What's New in Python 2.1c1?
1073===========================
1074
1075This list was significantly updated when 2.1c2 was released; the 2.1c1
1076release didn't mention most changes that were actually part of 2.1c1:
1077
1078Legal
1079
1080- Copyright was assigned to the Python Software Foundation (PSF) and a
1081 PSF license (very similar to the CNRI license) was added.
1082
1083- The CNRI copyright notice was updated to include 2001.
1084
1085Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001086
Guido van Rossumc9932722001-04-12 02:31:27 +00001087- After a public outcry, assignment to __debug__ is no longer illegal;
1088 instead, a warning is issued. It will become illegal in 2.2.
1089
Guido van Rossum5b08f132001-04-16 02:05:23 +00001090- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1091 "%#x" now always prepends "0x", even if the value is zero.
1092
1093- Fixed some nits in the bytecode compiler.
1094
1095- Fixed core dumps when calling certain kinds of non-functions.
1096
1097- Fixed various core dumps caused by reference count bugs.
1098
1099Build and Ports
1100
1101- Use INSTALL_SCRIPT to install script files.
1102
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001103- New port: SCO Unixware 7, by Billy G. Allie.
1104
Guido van Rossum5b08f132001-04-16 02:05:23 +00001105- Updated RISCOS port.
1106
1107- Updated BeOS port and notes.
1108
1109- Various other porting problems resolved.
1110
1111Library
1112
1113- The TERMIOS and SOCKET modules are now truly obsolete and
1114 unnecessary. Their symbols are incorporated in the termios and
1115 socket modules.
1116
1117- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1118 better tests for pickling.
1119
1120- threading: make Condition.wait() robust against KeyboardInterrupt.
1121
1122- zipfile: add support to zipfile to support opening an archive
1123 represented by an open file rather than a file name. Fix bug where
1124 the archive was not properly closed. Fixed a bug in this bugfix
1125 where flush() was called for a read-only file.
1126
1127- imputil: added an uninstall() method to the ImportManager.
1128
1129- Canvas: fixed bugs in lower() and tkraise() methods.
1130
1131- SocketServer: API change (added overridable close_request() method)
1132 so that the TCP server can explicitly close the request.
1133
1134- pstats: Eric Raymond added a simple interactive statistics browser,
1135 invoked when the module is run as a script.
1136
1137- locale: fixed a problem in format().
1138
1139- webbrowser: made it work when the BROWSER environment variable has a
1140 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1141 KDE 2. Fixed some other nits.
1142
1143- unittest: changes to allow using a different exception than
1144 AssertionError, and added a few more function aliases. Some other
1145 small changes.
1146
1147- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1148
1149- asynchat: fixed a critical bug in asynchat that slipped through the
1150 2.1b2 release. Fixed another rare bug.
1151
1152- Fix some unqualified except: clauses (always a bad code example).
1153
1154XML
1155
1156- pyexpat: new API get_version_string().
1157
1158- Fixed some minidom bugs.
1159
1160Extensions
1161
1162- Fixed a core dump in _weakref. Removed the weakref.mapping()
1163 function (it adds nothing to the API).
1164
1165- Rationalized the use of header files in the readline module, to make
1166 it compile (albeit with some warnings) with the very recent readline
1167 4.2, without breaking for earlier versions.
1168
1169- Hopefully fixed a buffering problem in linuxaudiodev.
1170
1171- Attempted a fix to make the OpenSSL support in the socket module
1172 work again with pre-0.9.5 versions of OpenSSL.
1173
1174Tests
1175
1176- Added a test case for asynchat and asyncore.
1177
1178- Removed coupling between tests where one test failing could break
1179 another.
1180
1181Tools
1182
1183- Ping added an interactive help browser to pydoc, fixed some nits
1184 in the rest of the pydoc code, and added some features to his
1185 inspect module.
1186
1187- An updated python-mode.el version 4.1 which integrates Ken
1188 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1189 much nicer in XEmacs and Emacs. When stepping through your program
1190 with pdb, in either the shell window or the *Python* window, the
1191 source file and line will be tracked by an arrow. Very cool!
1192
1193- IDLE: syntax warnings in interactive mode are changed into errors.
1194
1195- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001196 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001197
1198- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001199
Barry Warsaw11e89c72001-04-11 20:37:57 +00001200
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001201What's New in Python 2.1 beta 2?
1202================================
1203
Guido van Rossum053ae352001-03-22 14:17:21 +00001204(Unlisted are many fixed bugs, more documentation, etc.)
1205
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001206Core language, builtins, and interpreter
1207
Guido van Rossum053ae352001-03-22 14:17:21 +00001208- The nested scopes work (enabled by "from __future__ import
1209 nested_scopes") is completed; in particular, the future now extends
1210 into code executed through exec, eval() and execfile(), and into the
1211 interactive interpreter.
1212
1213- When calling a base class method (e.g. BaseClass.__init__(self)),
1214 this is now allowed even if self is not strictly spoken a class
1215 instance (e.g. when using metaclasses or the Don Beaudry hook).
1216
1217- Slice objects are now comparable but not hashable; this prevents
1218 dict[:] from being accepted but meaningless.
1219
1220- Complex division is now calculated using less braindead algorithms.
1221 This doesn't change semantics except it's more likely to give useful
1222 results in extreme cases. Complex repr() now uses full precision
1223 like float repr().
1224
1225- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1226
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001227- It is illegal to assign to the name __debug__, which is set when the
1228 interpreter starts. It is effectively a compile-time constant.
1229
1230- A warning will be issued if a global statement for a variable
1231 follows a use or assignment of that variable.
1232
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001233Standard library
1234
Guido van Rossum053ae352001-03-22 14:17:21 +00001235- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1236 inspired by JUnit), is now part of the standard library. You now
1237 have a choice of two testing frameworks: unittest requires you to
1238 write testcases as separate code, doctest gathers them from
1239 docstrings. Both approaches have their advantages and
1240 disadvantages.
1241
1242- A new module Tix was added, which wraps the Tix extension library
1243 for Tk. With that module, it is not necessary to statically link
1244 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1245 require" command. See Demo/tix/.
1246
1247- tzparse.py is now obsolete.
1248
1249- In gzip.py, the seek() and tell() methods are removed -- they were
1250 non-functional anyway, and it's better if callers can test for their
1251 existence with hasattr().
1252
1253Python/C API
1254
1255- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1256 that's already in the dictionary during a PyDict_Next() iteration.
1257 This used to fail occasionally when a dictionary resize operation
1258 could be triggered that would rehash all the keys. All other
1259 modifications to the dictionary are still off-limits during a
1260 PyDict_Next() iteration!
1261
1262- New extended APIs related to passing compiler variables around.
1263
1264- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1265 implement isinstance() and issubclass().
1266
1267- Py_BuildValue() now has a "D" conversion to create a Python complex
1268 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001269
Fred Drake4e262a92001-03-22 18:26:47 +00001270- Extensions types which support weak references must now set the
1271 field allocated for the weak reference machinery to NULL themselves;
1272 this is done to avoid the cost of checking each object for having a
1273 weakly referencable type in PyObject_INIT(), since most types are
1274 not weakly referencable.
1275
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001276- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1277 free variables and cell variables to and from the frame's f_locals.
1278
1279- Variants of several functions defined in pythonrun.h have been added
1280 to support the nested_scopes future statement. The variants all end
1281 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1282 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1283 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001284 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001285
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001286Distutils
1287
1288- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1289 into the release tree.
1290
Tim Peters0e57abf2001-05-02 07:39:38 +00001291- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001292 (an uninstaller, more customization of the installer's display)
1293
1294- from Jack Jansen: added Mac-specific code to generate a dialog for
1295 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001296 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001297 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001298
1299- added 'platforms' and 'keywords' to the set of metadata that can be
1300 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001301
1302- applied patches from Jason Tishler to make the compiler class work with
1303 Cygwin.
1304
1305
Tim Peters2fe289a2001-03-01 22:19:38 +00001306What's New in Python 2.1 beta 1?
1307================================
Tim Petersd66595f2001-02-04 03:09:53 +00001308
1309Core language, builtins, and interpreter
1310
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001311- Following an outcry from the community about the amount of code
1312 broken by the nested scopes feature introduced in 2.1a2, we decided
1313 to make this feature optional, and to wait until Python 2.2 (or at
1314 least 6 months) to make it standard. The option can be enabled on a
1315 per-module basis by adding "from __future__ import nested_scopes" at
1316 the beginning of a module (before any other statements, but after
1317 comments and an optional docstring). See PEP 236 (Back to the
1318 __future__) for a description of the __future__ statement. PEP 227
1319 (Statically Nested Scopes) has been updated to reflect this change,
1320 and to clarify the semantics in a number of endcases.
1321
1322- The nested scopes code, when enabled, has been hardened, and most
1323 bugs and memory leaks in it have been fixed.
1324
1325- Compile-time warnings are now generated for a number of conditions
1326 that will break or change in meaning when nested scopes are enabled:
1327
1328 - Using "from...import *" or "exec" without in-clause in a function
1329 scope that also defines a lambda or nested function with one or
1330 more free (non-local) variables. The presence of the import* or
1331 bare exec makes it impossible for the compiler to determine the
1332 exact set of local variables in the outer scope, which makes it
1333 impossible to determine the bindings for free variables in the
1334 inner scope. To avoid the warning about import *, change it into
1335 an import of explicitly name object, or move the import* statement
1336 to the global scope; to avoid the warning about bare exec, use
1337 exec...in... (a good idea anyway -- there's a possibility that
1338 bare exec will be deprecated in the future).
1339
1340 - Use of a global variable in a nested scope with the same name as a
1341 local variable in a surrounding scope. This will change in
1342 meaning with nested scopes: the name in the inner scope will
1343 reference the variable in the outer scope rather than the global
1344 of the same name. To avoid the warning, either rename the outer
1345 variable, or use a global statement in the inner function.
1346
Neil Schemenauera35c6882001-02-27 04:45:05 +00001347- An optional object allocator has been included. This allocator is
1348 optimized for Python objects and should be faster and use less memory
1349 than the standard system allocator. It is not enabled by default
1350 because of possible thread safety problems. The allocator is only
1351 protected by the Python interpreter lock and it is possible that some
1352 extension modules require a thread safe allocator. The object
1353 allocator can be enabled by providing the "--with-pymalloc" option to
1354 configure.
1355
Tim Petersd66595f2001-02-04 03:09:53 +00001356Standard library
1357
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001358- pyexpat now detects the expat version if expat.h defines it. A
1359 number of additional handlers are provided, which are only available
1360 since expat 1.95. In addition, the methods SetParamEntityParsing and
1361 GetInputContext of Parser objects are available with 1.95.x
1362 only. Parser objects now provide the ordered_attributes and
1363 specified_attributes attributes. A new module expat.model was added,
1364 which offers a number of additional constants if 1.95.x is used.
1365
1366- xml.dom offers the new functions registerDOMImplementation and
1367 getDOMImplementation.
1368
1369- xml.dom.minidom offers a toprettyxml method. A number of DOM
1370 conformance issues have been resolved. In particular, Element now
1371 has an hasAttributes method, and the handling of namespaces was
1372 improved.
1373
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001374- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1375 getting information about live Python code, and pydoc.py, a module
1376 for interactively converting docstrings to HTML or text.
1377 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001378 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001379 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1380 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001381
Tim Peters1eff7962001-03-01 02:31:33 +00001382- New library module difflib.py, primarily packaging the SequenceMatcher
1383 class at the heart of the popular ndiff.py file-comparison tool.
1384
1385- doctest.py (a framework for verifying Python code examples in docstrings)
1386 is now part of the std library.
1387
Tim Petersd66595f2001-02-04 03:09:53 +00001388Windows changes
1389
Guido van Rossume3955a82001-03-02 14:05:59 +00001390- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1391 small GUI that lets you browse the module docstrings using your
1392 default web browser.
1393
Tim Peters1eff7962001-03-01 02:31:33 +00001394- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1395 Platforms) is implemented. See
1396
1397 http://python.sourceforge.net/peps/pep-0235.html
1398
1399 for full details, especially the "Current Lower-Left Semantics" section.
1400 The new Windows import rules are simpler than before:
1401
1402 A. If the PYTHONCASEOK environment variable exists, same as
1403 before: silently accept the first case-insensitive match of any
1404 kind; raise ImportError if none found.
1405
1406 B. Else search sys.path for the first case-sensitive match; raise
1407 ImportError if none found.
1408
1409 The same rules have been implented on other platforms with case-
1410 insensitive but case-preserving filesystems too (including Cygwin, and
1411 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001412
Tim Peters25a9ce32001-02-19 07:06:36 +00001413- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1414 what it's supposed to do (and does do under NT and 2000) via direct
1415 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001416 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001417 all Win9x systems before.
1418
Tim Peters1eff7962001-03-01 02:31:33 +00001419- Build: Subproject _test (effectively) renamed to _testcapi.
1420
Tim Peters2fe289a2001-03-01 22:19:38 +00001421New platforms
1422
1423- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1424 Thanks to Steven Majewski!
1425
1426- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1427 Tishler!
1428
Guido van Rossum9089b272001-03-02 06:49:50 +00001429- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1430 Schwertberger! See RISCOS/README for more information -- it seems
1431 that because of the bizarre filename conventions on RISCOS, no port
1432 to that platform is easy. Note that the new variable os.endsep is
1433 silently supported in order to make life easier on this platform,
1434 but we don't advertise it because it's not worth for most folks to
1435 care about RISCOS portability.
1436
Tim Peters25a9ce32001-02-19 07:06:36 +00001437
Tim Petersd7b5e882001-01-25 03:36:26 +00001438What's New in Python 2.1 alpha 2?
1439=================================
Tim Peters40ead762001-01-27 05:35:26 +00001440
Tim Petersd7b5e882001-01-25 03:36:26 +00001441Core language, builtins, and interpreter
1442
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001443- Scopes nest. If a name is used in a function or class, but is not
1444 local, the definition in the nearest enclosing function scope will
1445 be used. One consequence of this change is that lambda statements
1446 could reference variables in the namespaces where the lambda is
1447 defined. In some unusual cases, this change will break code.
1448
1449 In all previous version of Python, names were resolved in exactly
1450 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001451 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001452 function A is defined within a function B, the names bound in B are
1453 not visible in A. The new rules make names bound in B visible in A,
1454 unless A contains a name binding that hides the binding in B.
1455
1456 Section 4.1 of the reference manual describes the new scoping rules
1457 in detail. The test script in Lib/test/test_scope.py demonstrates
1458 some of the effects of the change.
1459
1460 The new rules will cause existing code to break if it defines nested
1461 functions where an outer function has local variables with the same
1462 name as globals or builtins used by the inner function. Example:
1463
1464 def munge(str):
1465 def helper(x):
1466 return str(x)
1467 if type(str) != type(''):
1468 str = helper(str)
1469 return str.strip()
1470
1471 Under the old rules, the name str in helper() is bound to the
1472 builtin function str(). Under the new rules, it will be bound to
1473 the argument named str and an error will occur when helper() is
1474 called.
1475
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001476- The compiler will report a SyntaxError if "from ... import *" occurs
1477 in a function or class scope. The language reference has documented
1478 that this case is illegal, but the compiler never checked for it.
1479 The recent introduction of nested scope makes the meaning of this
1480 form of name binding ambiguous. In a future release, the compiler
1481 may allow this form when there is no possibility of ambiguity.
1482
Tim Peters40ead762001-01-27 05:35:26 +00001483- repr(string) is easier to read, now using hex escapes instead of octal,
1484 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1485
1486 >>> "\texample \r\n" + chr(0) + chr(255)
1487 '\texample \r\n\x00\xff' # in 2.1
1488 '\011example \015\012\000\377' # in 2.0
1489
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001490- Functions are now compared and hashed by identity, not by value, since
1491 the func_code attribute is writable.
1492
Fred Drakefb9d7122001-02-01 20:00:40 +00001493- Weak references (PEP 205) have been added. This involves a few
1494 changes in the core, an extension module (_weakref), and a Python
1495 module (weakref). The weakref module is the public interface. It
1496 includes support for "explicit" weak references, proxy objects, and
1497 mappings with weakly held values.
1498
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001499- A 'continue' statement can now appear in a try block within the body
1500 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001501 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001502
Tim Petersd7b5e882001-01-25 03:36:26 +00001503Standard library
1504
Barry Warsaw30dbd142001-01-31 22:14:01 +00001505- mailbox.py now has a new class, PortableUnixMailbox which is
1506 identical to UnixMailbox but uses a more portable scheme for
1507 determining From_ separators. Also, the constructors for all the
1508 classes in this module have a new optional `factory' argument, which
1509 is a callable used when new message classes must be instantiated by
1510 the next() method.
1511
Tim Petersd7b5e882001-01-25 03:36:26 +00001512- random.py is now self-contained, and offers all the functionality of
1513 the now-deprecated whrandom.py. See the docs for details. random.py
1514 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001515 and restoring the internal state of the generator; and jumpahead(n),
1516 for quickly forcing the internal state to be the same as if n calls to
1517 random() had been made. The latter is particularly useful for multi-
1518 threaded programs, creating one instance of the random.Random() class for
1519 each thread, then using .jumpahead() to force each instance to use a
1520 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001521
Tim Peters0de88fc2001-02-01 04:59:18 +00001522- random.py's seed() function is new. For bit-for-bit compatibility with
1523 prior releases, use the whseed function instead. The new seed function
1524 addresses two problems: (1) The old function couldn't produce more than
1525 about 2**24 distinct internal states; the new one about 2**45 (the best
1526 that can be done in the Wichmann-Hill generator). (2) The old function
1527 sometimes produced identical internal states when passed distinct
1528 integers, and there was no simple way to predict when that would happen;
1529 the new one guarantees to produce distinct internal states for all
1530 arguments in [0, 27814431486576L).
1531
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001532- The socket module now supports raw packets on Linux. The socket
1533 family is AF_PACKET.
1534
Tim Peters9ea17ac2001-02-02 05:57:15 +00001535- test_capi.py is a start at running tests of the Python C API. The tests
1536 are implemented by the new Modules/_testmodule.c.
1537
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001538- A new extension module, _symtable, provides provisional access to the
1539 internal symbol table used by the Python compiler. A higher-level
1540 interface will be added on top of _symtable in a future release.
1541
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001542- Removed the obsolete soundex module.
1543
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001544- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1545 the isSameNode method; NamedNodeMap the get method.
1546
1547- xml.sax.expatreader supports the lexical handler property; it
1548 generates comment, startCDATA, and endCDATA events.
1549
Tim Petersee826f82001-01-31 19:39:44 +00001550Windows changes
1551
1552- Build procedure: the zlib project is built in a different way that
1553 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001554 the zlib binary used. See PCbuild\readme.txt for details. Your old
1555 zlib-related directories can be deleted; you'll need to download fresh
1556 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001557
Tim Peters9ea17ac2001-02-02 05:57:15 +00001558- Build: New subproject _test for the benefit of test_capi.py (see above).
1559
Tim Petersb16c56f2001-02-02 21:24:51 +00001560- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1561 interface to some Python compiler internals).
1562
1563- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001564 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001565
Tim Petersa3a3a032000-11-30 05:22:44 +00001566What's New in Python 2.1 alpha 1?
1567=================================
1568
1569Core language, builtins, and interpreter
1570
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001571- There is a new Unicode companion to the PyObject_Str() API
1572 called PyObject_Unicode(). It behaves in the same way as the
1573 former, but assures that the returned value is an Unicode object
1574 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001575
Guido van Rossumf98eda02001-01-17 15:54:45 +00001576- The comparison operators support "rich comparison overloading" (PEP
1577 207). C extension types can provide a rich comparison function in
1578 the new tp_richcompare slot in the type object. The cmp() function
1579 and the C function PyObject_Compare() first try the new rich
1580 comparison operators before trying the old 3-way comparison. There
1581 is also a new C API PyObject_RichCompare() (which also falls back on
1582 the old 3-way comparison, but does not constrain the outcome of the
1583 rich comparison to a Boolean result).
1584
1585 The rich comparison function takes two objects (at least one of
1586 which is guaranteed to have the type that provided the function) and
1587 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1588 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1589 object, which may be NotImplemented (in which case the tp_compare
1590 slot function is used as a fallback, if defined).
1591
1592 Classes can overload individual comparison operators by defining one
1593 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001594 __ge__. There are no explicit "reflected argument" versions of
1595 these; instead, __lt__ and __gt__ are each other's reflection,
1596 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1597 reflection (similar at the C level). No other implications are
1598 made; in particular, Python does not assume that == is the Boolean
1599 inverse of !=, or that < is the Boolean inverse of >=. This makes
1600 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001601
1602 Classes or types that want to implement (in)equality tests but not
1603 the ordering operators (i.e. unordered types) should implement ==
1604 and !=, and raise an error for the ordering operators.
1605
Guido van Rossuma88479f2001-01-18 14:28:08 +00001606 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001607 Boolean; e.g. a matrix type might want to return a matrix of bits
1608 for A < B, giving elementwise comparisons. Such types should ensure
1609 that any interpretation of their value in a Boolean context raises
1610 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1611 at the C level) to always raise an exception.
1612
Guido van Rossuma88479f2001-01-18 14:28:08 +00001613- Complex numbers use rich comparisons to define == and != but raise
1614 an exception for <, <=, > and >=. Unfortunately, this also means
1615 that cmp() of two complex numbers raises an exception when the two
1616 numbers differ. Since it is not mathematically meaningful to compare
1617 complex numbers except for equality, I hope that this doesn't break
1618 too much code.
1619
Tim Peters3389f192001-02-18 08:48:49 +00001620- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001621 not defined by the language, other than that it's arbitrary but
1622 consistent (see the Reference Manual). An implementation detail changed
1623 in 2.1a1 such that None now compares less than any other object. Code
1624 relying on this new behavior (like code that relied on the previous
1625 behavior) does so at its own risk.
1626
Barry Warsaw573b5412001-01-15 20:43:18 +00001627- Functions and methods now support getting and setting arbitrarily
1628 named attributes (PEP 232). Functions have a new __dict__
1629 (a.k.a. func_dict) which hold the function attributes. Methods get
1630 and set attributes on their underlying im_func. It is a TypeError
1631 to set an attribute on a bound method.
1632
Guido van Rossum051e3352001-01-15 19:11:10 +00001633- The xrange() object implementation has been improved so that
1634 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1635 limitation that in this case len(xrange(sys.maxint)) can't be
1636 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1637 work fine as long as the index i doesn't actually reach 2**31.
1638 (Python uses regular ints for sequence and string indices; fixing
1639 that is much more work.)
1640
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001641- Two changes to from...import:
1642
Guido van Rossumba381232001-02-03 15:06:40 +00001643 1) "from M import X" now works even if (after loading module M)
1644 sys.modules['M'] is not a real module; it's basically a getattr()
1645 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001646
1647 2) "from M import *" now looks for M.__all__ to decide which names to
1648 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1649 filters out names starting with '_' as before. Whether or not
1650 __all__ exists, there's no restriction on the type of M.
1651
Guido van Rossumf61f1662001-01-10 20:13:55 +00001652- File objects have a new method, xreadlines(). This is the fastest
1653 way to iterate over all lines in a file:
1654
1655 for line in file.xreadlines():
1656 ...do something to line...
1657
1658 See the xreadlines module (mentioned below) for how to do this for
1659 other file-like objects.
1660
1661- Even if you don't use file.xreadlines(), you may expect a speedup on
1662 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001663 quite a bit in platform-specific ways: on systems (like Linux) that
1664 support flockfile(), getc_unlocked(), and funlockfile(), those are
1665 used by default. On systems (like Windows) without getc_unlocked(),
1666 a complicated (but still thread-safe) method using fgets() is used by
1667 default.
1668
Tim Petersd52269b2001-01-25 06:23:18 +00001669 You can force use of the fgets() method by #define'ing
1670 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001671 getc_unlocked()).
1672
Tim Petersd52269b2001-01-25 06:23:18 +00001673 You can force fgets() not to be used by #define'ing
1674 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001675 test_bufio.py fails -- and let us know if it does!).
1676
1677- In addition, the fileinput module, while still slower than the other
1678 methods on most platforms, has been sped up too, by using
1679 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001680
1681- Support for run-time warnings has been added, including a new
1682 command line option (-W) to specify the disposition of warnings.
1683 See the description of the warnings module below.
1684
1685- Extensive changes have been made to the coercion code. This mostly
1686 affects extension modules (which can now implement mixed-type
1687 numerical operators without having to use coercion), but
1688 occasionally, in boundary cases the coercion semantics have changed
1689 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001690 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001691 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001692 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001693
Guido van Rossumf98eda02001-01-17 15:54:45 +00001694- In connection with the coercion changes, a new built-in singleton
1695 object, NotImplemented is defined. This can be returned for
1696 operations that wish to indicate they are not implemented for a
1697 particular combination of arguments. From C, this is
1698 Py_NotImplemented.
1699
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001700- The interpreter accepts now bytecode files on the command line even
1701 if they do not have a .pyc or .pyo extension. On Linux, after executing
1702
Martin v. Löwise214baa2001-02-04 22:37:56 +00001703import imp,sys,string
1704magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1705reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1706open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001707
1708 any byte code file can be used as an executable (i.e. as an argument
1709 to execve(2)).
1710
Tim Peters9940b802000-12-01 07:59:35 +00001711- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001712 character. In 1.6 and earlier, they never produced a sign,
1713 and raised an error if the value of the long was too large
1714 to fit in a Python int. In 2.0, they produced a sign if and
1715 only if too large to fit in an int. This was inconsistent
1716 across platforms (because the size of an int varies across
1717 platforms), and inconsistent with hex() and oct(). Example:
1718
1719 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001720 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001721 'ffffffbe' # in 2.0 and before, on 32-bit machines
1722 >>> hex(-0x42L)
1723 '-0x42L' # in all versions of Python
1724
Tim Peters9940b802000-12-01 07:59:35 +00001725 The behavior of %d formats for negative Python longs remains
1726 the same as in 2.0 (although in 1.6 and before, they raised
1727 an error if the long didn't fit in a Python int).
1728
1729 %u formats don't make sense for Python longs, but are allowed
1730 and treated the same as %d in 2.1. In 2.0, a negative long
1731 formatted via %u produced a sign if and only if too large to
1732 fit in an int. In 1.6 and earlier, a negative long formatted
1733 via %u raised an error if it was too big to fit in an int.
1734
Guido van Rossum3661d392000-12-12 22:10:31 +00001735- Dictionary objects have an odd new method, popitem(). This removes
1736 an arbitrary item from the dictionary and returns it (in the form of
1737 a (key, value) pair). This can be useful for algorithms that use a
1738 dictionary as a bag of "to do" items and repeatedly need to pick one
1739 item. Such algorithms normally end up running in quadratic time;
1740 using popitem() they can usually be made to run in linear time.
1741
Tim Peters36cdad12000-12-29 02:06:45 +00001742Standard library
1743
Thomas Woutersfe385252001-01-19 23:16:56 +00001744- In the time module, the time argument to the functions strftime,
1745 localtime, gmtime, asctime and ctime is now optional, defaulting to
1746 the current time (in the local timezone).
1747
Guido van Rossumda91f222001-01-15 16:36:08 +00001748- The ftplib module now defaults to passive mode, which is deemed a
1749 more useful default given that clients are often inside firewalls
1750 these days. Note that this could break if ftplib is used to connect
1751 to a *server* that is inside a firewall, from outside; this is
1752 expected to be a very rare situation. To fix that, you can call
1753 ftp.set_pasv(0).
1754
Martin v. Löwis10a27872001-01-13 09:54:41 +00001755- The module site now treats .pth files not only for path configuration,
1756 but also supports extensions to the initialization code: Lines starting
1757 with import are executed.
1758
Guido van Rossumf61f1662001-01-10 20:13:55 +00001759- There's a new module, warnings, which implements a mechanism for
1760 issuing and filtering warnings. There are some new built-in
1761 exceptions that serve as warning categories, and a new command line
1762 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1763 turns warnings into errors). warnings.warn(message[, category])
1764 issues a warning message; this can also be called from C as
1765 PyErr_Warn(category, message).
1766
1767- A new module xreadlines was added. This exports a single factory
1768 function, xreadlines(). The intention is that this code is the
1769 absolutely fastest way to iterate over all lines in an open
1770 file(-like) object:
1771
1772 import xreadlines
1773 for line in xreadlines.xreadlines(file):
1774 ...do something to line...
1775
1776 This is equivalent to the previous the speed record holder using
1777 file.readlines(sizehint). Note that if file is a real file object
1778 (as opposed to a file-like object), this is equivalent:
1779
1780 for line in file.xreadlines():
1781 ...do something to line...
1782
Tim Peters36cdad12000-12-29 02:06:45 +00001783- The bisect module has new functions bisect_left, insort_left,
1784 bisect_right and insort_right. The old names bisect and insort
1785 are now aliases for bisect_right and insort_right. XXX_right
1786 and XXX_left methods differ in what happens when the new element
1787 compares equal to one or more elements already in the list: the
1788 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001789 right. Code that doesn't care where equal elements end up should
1790 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001791
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001792- The new curses.panel module wraps the panel library that forms part
1793 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1794
Guido van Rossumf61f1662001-01-10 20:13:55 +00001795- The SocketServer module now sets the allow_reuse_address flag by
1796 default in the TCPServer class.
1797
1798- A new function, sys._getframe(), returns the stack frame pointer of
1799 the caller. This is intended only as a building block for
1800 higher-level mechanisms such as string interpolation.
1801
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001802- The pyexpat module supports a number of new handlers, which are
1803 available only in expat 1.2. If invocation of a callback fails, it
1804 will report an additional frame in the traceback. Parser objects
1805 participate now in garbage collection. If expat reports an unknown
1806 encoding, pyexpat will try to use a Python codec; that works only
1807 for single-byte charsets. The parser type objects is exposed as
1808 XMLParserObject.
1809
1810- xml.dom now offers standard definitions for symbolic node type and
1811 exception code constants, and a hierarchy of DOM exceptions. minidom
1812 was adjusted to use them.
1813
1814- The conformance of xml.dom.minidom to the DOM specification was
1815 improved. It detects a number of additional error cases; the
1816 previous/next relationship works even when the tree is modified;
1817 Node supports the normalize() method; NamedNodeMap, DocumentType and
1818 DOMImplementation classes were added; Element supports the
1819 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1820 method.
1821
Guido van Rossumf61f1662001-01-10 20:13:55 +00001822Build issues
1823
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001824- For Unix (and Unix-compatible) builds, configuration and building of
1825 extension modules is now greatly automated. Rather than having to
1826 edit the Modules/Setup file to indicate which modules should be
1827 built and where their include files and libraries are, a
1828 distutils-based setup.py script now takes care of building most
1829 extension modules. All extension modules built this way are built
1830 as shared libraries. Only a few modules that must be linked
1831 statically are still listed in the Setup file; you won't need to
1832 edit their configuration.
1833
1834- Python should now build out of the box on Cygwin. If it doesn't,
1835 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001836
1837- Python now always uses its own (renamed) implementation of getopt()
1838 -- there's too much variation among C library getopt()
1839 implementations.
1840
1841- C++ compilers are better supported; the CXX macro is always set to a
1842 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001843
Tim Petersd92dfe02000-12-12 01:18:41 +00001844Windows changes
1845
1846- select module: By default under Windows, a select() call
1847 can specify no more than 64 sockets. Python now boosts
1848 this Microsoft default to 512. If you need even more than
1849 that, see the MS docs (you'll need to #define FD_SETSIZE
1850 and recompile Python from source).
1851
Guido van Rossumf61f1662001-01-10 20:13:55 +00001852- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1853 subdirectory is no more!
1854
Tim Petersa3a3a032000-11-30 05:22:44 +00001855
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001856What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001857=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001858
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001859Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001860changes are in the file HISTORY. If you are making the jump directly
1861from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1862HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001863
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001864Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1865the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1866http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001867
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001868--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001869
1870======================================================================
1871
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001872What's new in 2.0 (since release candidate 1)?
1873==============================================
1874
1875Standard library
1876
1877- The copy_reg module was modified to clarify its intended use: to
1878 register pickle support for extension types, not for classes.
1879 pickle() will raise a TypeError if it is passed a class.
1880
1881- Fixed a bug in gettext's "normalize and expand" code that prevented
1882 it from finding an existing .mo file.
1883
1884- Restored support for HTTP/0.9 servers in httplib.
1885
Tim Peters989b7b92000-10-16 20:24:53 +00001886- The math module was changed to stop raising OverflowError in case of
1887 underflow, and return 0 instead in underflow cases. Whether Python
1888 used to raise OverflowError in case of underflow was platform-
1889 dependent (it did when the platform math library set errno to ERANGE
1890 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001891
1892- Fixed a bug in StringIO that occurred when the file position was not
1893 at the end of the file and write() was called with enough data to
1894 extend past the end of the file.
1895
1896- Fixed a bug that caused Tkinter error messages to get lost on
1897 Windows. The bug was fixed by replacing direct use of
1898 interp->result with Tcl_GetStringResult(interp).
1899
1900- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1901 redirect response.
1902
1903- Several changes were made to distutils: Some debugging code was
1904 removed from util. Fixed the installer used when an external zip
1905 program (like WinZip) is not found; the source code for this
1906 installer is in Misc/distutils. check_lib() was modified to behave
1907 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1908 test for whether installed modules are on sys.path was changed to
1909 use both normcase() and normpath().
1910
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001911- Several minor bugs were fixed in the xml package (the minidom,
1912 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001913
1914- The regression test driver (regrtest.py) behavior when invoked with
1915 -l changed: It now reports a count of objects that are recognized as
1916 garbage but not freed by the garbage collector.
1917
Tim Peters989b7b92000-10-16 20:24:53 +00001918- The regression test for the math module was changed to test
1919 exceptional behavior when the test is run in verbose mode. Python
1920 cannot yet guarantee consistent exception behavior across platforms,
1921 so the exception part of test_math is run only in verbose mode, and
1922 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001923
1924Internals
1925
1926- PyOS_CheckStack() has been disabled on Win64, where it caused
1927 test_sre to fail.
1928
1929Build issues
1930
1931- Changed compiler flags, so that gcc is always invoked with -Wall and
1932 -Wstrict-prototypes. Users compiling Python with GCC should see
1933 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001934 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001935 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001936
Tim Petersa3a3a032000-11-30 05:22:44 +00001937- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001938
1939Tools and other miscellany
1940
1941- The compiler in Tools/compiler was updated to support the new
1942 language features introduced in 2.0: extended print statement, list
1943 comprehensions, and augmented assignments. The new compiler should
1944 also be backwards compatible with Python 1.5.2; the compiler will
1945 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001946 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001947
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001948What's new in 2.0 release candidate 1 (since beta 2)?
1949=====================================================
1950
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001951What is release candidate 1?
1952
1953We believe that release candidate 1 will fix all known bugs that we
1954intend to fix for the 2.0 final release. This release should be a bit
1955more stable than the previous betas. We would like to see even more
1956widespread testing before the final release, so we are producing this
1957release candidate. The final release will be exactly the same unless
1958any show-stopping (or brown bag) bugs are found by testers of the
1959release candidate.
1960
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001961All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001962to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001963
1964Core language, builtins, and interpreter
1965
1966- A bug that caused crashes when __coerce__ was used with augmented
1967 assignment, e.g. +=, was fixed.
1968
1969- Raise ZeroDivisionError when raising zero to a negative number,
1970 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1971 power operator and the result of math.pow(0.0, -2.0) will vary by
1972 platform. On Linux, it raises a ValueError.
1973
1974- A bug in Unicode string interpolation was fixed that occasionally
1975 caused errors with formats including "%%". For example, the
1976 following expression "%% %s" % u"abc" no longer raises a TypeError.
1977
1978- Compilation of deeply nested expressions raises MemoryError instead
1979 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1980
1981- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1982 rendering them useless. They are now written in binary mode again.
1983
1984Standard library
1985
1986- Keyword arguments are now accepted for most pattern and match object
1987 methods in SRE, the standard regular expression engine.
1988
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001989- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001990 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001991
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001992- Several bugs in the Unicode handling and error handling in _tkinter
1993 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001994
1995- Fix memory management errors in Merge() and Tkapp_Call() routines.
1996
1997- Several changes were made to cStringIO to make it compatible with
1998 the file-like object interface and with StringIO. If operations are
1999 performed on a closed object, an exception is raised. The truncate
2000 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002001 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002002
2003- There were many changes made to the linuxaudiodev module and its
2004 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002005 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002006
2007 Note that this module is named poorly, because it should work
2008 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002009 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002010
2011 The module now raises exceptions when errors occur instead of
2012 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2013 audio) and defines a getptr() method that calls the
2014 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2015
2016- The library_version attribute, introduced in an earlier beta, was
2017 removed because it can not be supported with early versions of the C
2018 readline library, which provides no way to determine the version at
2019 compile-time.
2020
2021- The binascii module is now enabled on Win64.
2022
Tim Peters46446d62000-10-09 21:19:31 +00002023- tokenize.py no longer suffers "recursion depth" errors when parsing
2024 programs with very long string literals.
2025
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002026Internals
2027
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002028- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002029 which is called when the interpreter starts up to determine where
2030 the standard library is installed. These vulnerabilities affect all
2031 previous versions of Python and can be exploited by setting very
2032 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2033 setuid Python script, although use of the wrapper in
2034 Misc/setuid-prog.c will eliminate the vulnerability.
2035
2036- Fixed garbage collection bugs in instance creation that were
2037 triggered when errors occurred during initialization. The solution,
2038 applied in cPickle and in PyInstance_New(), is to call
2039 PyObject_GC_Init() after the initialization of the object's
2040 container attributes is complete.
2041
2042- pyexpat adds definitions of PyModule_AddStringConstant and
2043 PyModule_AddObject if the Python version is less than 2.0, which
2044 provides compatibility with PyXML on Python 1.5.2.
2045
2046- If the platform has a bogus definition for LONG_BIT (the number of
2047 bits in a long), an error will be reported at compile time.
2048
2049- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2050 collection crashes and possibly other, unreported crashes.
2051
2052- Fixed a memory leak in _PyUnicode_Fini().
2053
2054Build issues
2055
2056- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002057 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002058 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002059
2060- The mmap.PAGESIZE constant is now initialized using sysconf when
2061 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2062
2063- The md5 file should now compile on all platforms.
2064
2065- The select module now compiles on platforms that do not define
2066 POLLRDNORM and related constants.
2067
2068- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002069 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002070
Jeremy Hylton10921202000-10-09 18:34:12 +00002071- BeOS: A number of changes were made to the build and installation
2072 process. ar-fake now operates on a directory of object files.
2073 dl_export.h is gone, and its macros now appear on the mwcc command
2074 line during build on PPC BeOS.
2075
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002076- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002077 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002078
2079- Cygwin: Support for shared libraries, Tkinter, and sockets.
2080
2081- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2082
2083Tools and other miscellany
2084
2085- Removed debugging prints from main used with freeze.
2086
Tim Peters46446d62000-10-09 21:19:31 +00002087- IDLE auto-indent no longer crashes when it encounters Unicode
2088 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002089
2090What's new in 2.0 beta 2 (since beta 1)?
2091========================================
2092
2093Core language, builtins, and interpreter
2094
Tim Peters482c0212000-09-26 06:33:09 +00002095- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002096 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002097
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002098- Add -h and -V command line options to print the usage message and
2099 Python version number and exit immediately.
2100
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002101- eval() and exec accept Unicode objects as code parameters.
2102
2103- getattr() and setattr() now also accept Unicode objects for the
2104 attribute name, which are converted to strings using the default
2105 encoding before lookup.
2106
2107- Multiplication on string and Unicode now does proper bounds
2108 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2109 string is too long."
2110
2111- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002112 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002113
Jeremy Hylton1b618592000-09-26 05:32:36 +00002114
2115Standard library and extensions
2116
Guido van Rossum5b08f132001-04-16 02:05:23 +00002117- socket module: the OpenSSL code now adds support for RAND_status()
2118 and EGD (Entropy Gathering Device).
2119
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002120- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002121 argument checking; it still takes no arguments.
2122
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002123- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002124
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002125- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002126
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002127- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002128
2129- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002130 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002131
2132- copy: Copy Unicode objects atomically.
2133
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002134- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002135
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002136- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002137
Fred Drake67233bc2000-09-26 16:40:27 +00002138- dbm: Add get() and setdefault() methods to dbm object. Add constant
2139 `library' to module that names the library used. Added doc strings
2140 and method names to error messages. Uses configure to determine
2141 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2142 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002143
2144- distutils: Update to version 0.9.3.
2145
2146- dl: Add several dl.RTLD_ constants.
2147
2148- fpectl: Now supported on FreeBSD.
2149
2150- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2151 found by the collector will be saved in gc.garbage. This is useful
2152 for debugging a program that creates reference cycles.
2153
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002154- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002155 of HTTP class. Do not close socket on zero-length response. Do not
2156 crash when server sends invalid content-length header.
2157
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002158- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002159
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002160- marshal: When reading a short, sign-extend on platforms where shorts
2161 are bigger than 16 bits. When reading a long, repair the unportable
2162 sign extension that was being done for 64-bit machines. (It assumed
2163 that signed right shift sign-extends.)
2164
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002165- operator: Add contains(), invert(), __invert__() as aliases for
2166 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002167
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002168- os: Add support for popen2() and popen3() on all platforms where
2169 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002170
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002171- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002172 clicking on a file in Explorer (or passing the file name to the
2173 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002174
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002175- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002176 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002177
2178- pickle: Now raises ValueError when an invalid pickle that contains
2179 a non-string repr where a string repr was expected. This behavior
2180 matches cPickle.
2181
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002182- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002183
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002184- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002185
2186- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002187 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002188 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002189
2190- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002191 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002192
2193- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002194 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002195 few cycles during startup since the first call to
2196 setdefaultencoding() will initialize the codec registry and the
2197 encodings package.
2198
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002199- socket: Support for size hint in readlines() method of object returned
2200 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002201
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002202- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002203 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002204 is followed by whitespace.
2205
Tim Petersa3a3a032000-11-30 05:22:44 +00002206- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002207
2208- struct: Check ranges for bytes and shorts.
2209
2210- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002211 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002212
2213- Tkinter: Image objects are now guaranteed to have unique ids. Set
2214 event.delta to zero if Tk version doesn't support mousewheel.
2215 Removed some debugging prints.
2216
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002217- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002218
Fred Drake67233bc2000-09-26 16:40:27 +00002219- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002220 which works around a bug in Norton AntiVirus 2000 that leads directly
2221 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002222
2223- xml: New version detection code allows PyXML to override standard
2224 XML package if PyXML version is greater than 0.6.1.
2225
Fred Drake64bb3802000-09-26 16:21:35 +00002226- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2227 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2228 tree only for nodes which are sufficiently interesting to a specific
2229 application. Does not provide the HTML-specific extensions. Still
2230 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002231
Fred Drake64bb3802000-09-26 16:21:35 +00002232- xml.sax: SAX 2 support for Python, including all the handler
2233 interfaces needed to process XML 1.0 compliant XML. Some
2234 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002235
Fred Drake64bb3802000-09-26 16:21:35 +00002236- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2237 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002238
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002239
Jeremy Hylton1b618592000-09-26 05:32:36 +00002240C API
2241
2242- Add three new convenience functions for module initialization --
2243 PyModule_AddObject(), PyModule_AddIntConstant(), and
2244 PyModule_AddStringConstant().
2245
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002246- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002247 removed and add #error to Python.h if NULL isn't defined after
2248 #include of stdio.h.
2249
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002250- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002251 backwards compatibility (at the source level) with old extensions.
2252
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002253- A wrapper API was added for signal() and sigaction(). Instead of
2254 either function, always use PyOS_getsig() to get a signal handler
2255 and PyOS_setsig() to set one. A new convenience typedef
2256 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002257
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002258- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002259 internal data buffer and size of a string object -- or the default
2260 encoded version of a Unicode object.
2261
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002262- PyString_Size() and PyString_AsString() accept Unicode objects.
2263
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002264- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002265 exists). INT_MAX and LONG_MAX will always be defined, even if
2266 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002267
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002268- PyFloat_FromString takes a second argument, pend, that was
2269 effectively useless. It is now officially useless but preserved for
2270 backwards compatibility. If the pend argument is not NULL, *pend is
2271 set to NULL.
2272
2273- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2274 for the attribute name. See note on getattr() above.
2275
2276- A few bug fixes to argument processing for Unicode.
2277 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2278 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2279 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002280 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002281
2282- Py_BuildValue accepts B format (for bgen-generated code).
2283
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002284
Jeremy Hylton1b618592000-09-26 05:32:36 +00002285Internals
2286
2287- On Unix, fix code for finding Python installation directory so that
2288 it works when argv[0] is a relative path.
2289
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002290- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002291 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002292 rather than by generating a copy of the object.
2293
Tim Peters482c0212000-09-26 06:33:09 +00002294- Several of the internal Unicode tables are much smaller now, and
2295 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002296
Jeremy Hylton97693b02000-09-26 17:42:51 +00002297- In the garbage collector: Fixed bug in collection of tuples. Fixed
2298 bug that caused some instances to be removed from the container set
2299 while they were still live. Fixed parsing in gc.set_debug() for
2300 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002301
2302- Fixed refcount problem in instance deallocation that only occurred
2303 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2304
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002305- On Windows, getpythonregpath is now protected against null data in
2306 registry key.
2307
2308- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002309 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002310
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002311
Jeremy Hylton1b618592000-09-26 05:32:36 +00002312Build and platform-specific issues
2313
2314- Better support of GNU Pth via --with-pth configure option.
2315
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002316- Python/C API now properly exposed to dynamically-loaded extension
2317 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002318
2319- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2320 Don't define MS_SYNC to be zero when it is undefined. Added missing
2321 prototypes in posixmodule.c.
2322
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002323- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002324 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002325
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002326- Fix largefile support on older NetBSD systems and OpenBSD by adding
2327 define for TELL64.
2328
2329
2330Tools and other miscellany
2331
2332- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2333
2334- freeze: The modulefinder now works with 2.0 opcodes.
2335
Tim Petersa3a3a032000-11-30 05:22:44 +00002336- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002337 Move hackery of sys.argv until after the Tk instance has been
2338 created, which allows the application-specific Tkinter
2339 initialization to be executed if present; also pass an explicit
2340 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002341
Jeremy Hylton1b618592000-09-26 05:32:36 +00002342
2343What's new in 2.0 beta 1?
2344=========================
2345
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002346Source Incompatibilities
2347------------------------
2348
2349None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2350such as single-argument append(), connect() and bind(), and changes to
2351str(long) and repr(float).
2352
2353
2354Binary Incompatibilities
2355------------------------
2356
2357- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2358with Python 2.0; these extensions will have to be rebuilt for Python
23592.0.
2360
2361- On Windows, attempting to import a third party extension built for
2362Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2363can do about this. Check your PYTHONPATH environment variable!
2364
2365- Python bytecode files (*.pyc and *.pyo) are not compatible between
2366releases.
2367
2368
2369Overview of Changes Since 1.6
2370-----------------------------
2371
2372There are many new modules (including brand new XML support through
2373the xml package, and i18n support through the gettext module); a list
2374of all new modules is included below. Lots of bugs have been fixed.
2375
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002376The process for making major new changes to the language has changed
2377since Python 1.6. Enhancements must now be documented by a Python
2378Enhancement Proposal (PEP) before they can be accepted.
2379
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002380There are several important syntax enhancements, described in more
2381detail below:
2382
2383 - Augmented assignment, e.g. x += 1
2384
2385 - List comprehensions, e.g. [x**2 for x in range(10)]
2386
2387 - Extended import statement, e.g. import Module as Name
2388
2389 - Extended print statement, e.g. print >> file, "Hello"
2390
2391Other important changes:
2392
2393 - Optional collection of cyclical garbage
2394
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002395Python Enhancement Proposal (PEP)
2396---------------------------------
2397
2398PEP stands for Python Enhancement Proposal. A PEP is a design
2399document providing information to the Python community, or describing
2400a new feature for Python. The PEP should provide a concise technical
2401specification of the feature and a rationale for the feature.
2402
2403We intend PEPs to be the primary mechanisms for proposing new
2404features, for collecting community input on an issue, and for
2405documenting the design decisions that have gone into Python. The PEP
2406author is responsible for building consensus within the community and
2407documenting dissenting opinions.
2408
2409The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002410
2411Augmented Assignment
2412--------------------
2413
2414This must have been the most-requested feature of the past years!
2415Eleven new assignment operators were added:
2416
Guido van Rossume905e952000-09-05 12:42:46 +00002417 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002418
2419For example,
2420
2421 A += B
2422
2423is similar to
2424
2425 A = A + B
2426
2427except that A is evaluated only once (relevant when A is something
2428like dict[index].attr).
2429
2430However, if A is a mutable object, A may be modified in place. Thus,
2431if A is a number or a string, A += B has the same effect as A = A+B
2432(except A is only evaluated once); but if a is a list, A += B has the
2433same effect as A.extend(B)!
2434
2435Classes and built-in object types can override the new operators in
2436order to implement the in-place behavior; the not-in-place behavior is
2437used automatically as a fallback when an object doesn't implement the
2438in-place behavior. For classes, the method name is derived from the
2439method name for the corresponding not-in-place operator by inserting
2440an 'i' in front of the name, e.g. __iadd__ implements in-place
2441__add__.
2442
2443Augmented assignment was implemented by Thomas Wouters.
2444
2445
2446List Comprehensions
2447-------------------
2448
2449This is a flexible new notation for lists whose elements are computed
2450from another list (or lists). The simplest form is:
2451
2452 [<expression> for <variable> in <sequence>]
2453
Guido van Rossum56db0952000-09-06 23:34:25 +00002454For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002455This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002456
2457You can also add a condition:
2458
2459 [<expression> for <variable> in <sequence> if <condition>]
2460
2461For example, [w for w in words if w == w.lower()] would yield the list
2462of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002463than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002464
2465You can also have nested for loops and more than one 'if' clause. For
2466example, here's a function that flattens a sequence of sequences::
2467
2468 def flatten(seq):
2469 return [x for subseq in seq for x in subseq]
2470
2471 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2472
2473This prints
2474
2475 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2476
2477List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002478Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002479
2480
2481Extended Import Statement
2482-------------------------
2483
2484Many people have asked for a way to import a module under a different
2485name. This can be accomplished like this:
2486
2487 import foo
2488 bar = foo
2489 del foo
2490
2491but this common idiom gets old quickly. A simple extension of the
2492import statement now allows this to be written as follows:
2493
2494 import foo as bar
2495
2496There's also a variant for 'from ... import':
2497
2498 from foo import bar as spam
2499
2500This also works with packages; e.g. you can write this:
2501
2502 import test.regrtest as regrtest
2503
2504Note that 'as' is not a new keyword -- it is recognized only in this
2505context (this is only possible because the syntax for the import
2506statement doesn't involve expressions).
2507
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002508Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002509
2510
2511Extended Print Statement
2512------------------------
2513
2514Easily the most controversial new feature, this extension to the print
2515statement adds an option to make the output go to a different file
2516than the default sys.stdout.
2517
2518For example, to write an error message to sys.stderr, you can now
2519write:
2520
2521 print >> sys.stderr, "Error: bad dog!"
2522
2523As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002524evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002525
2526 print >> None, "Hello world"
2527
2528is equivalent to
2529
2530 print "Hello world"
2531
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002532Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002533
2534
2535Optional Collection of Cyclical Garbage
2536---------------------------------------
2537
2538Python is now equipped with a garbage collector that can hunt down
2539cyclical references between Python objects. It's no replacement for
2540reference counting; in fact, it depends on the reference counts being
2541correct, and decides that a set of objects belong to a cycle if all
2542their reference counts can be accounted for from their references to
2543each other. This devious scheme was first proposed by Eric Tiedemann,
2544and brought to implementation by Neil Schemenauer.
2545
2546There's a module "gc" that lets you control some parameters of the
2547garbage collection. There's also an option to the configure script
2548that lets you enable or disable the garbage collection. In 2.0b1,
2549it's on by default, so that we (hopefully) can collect decent user
2550experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002551performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002552off by default in the final 2.0 release.
2553
2554
2555Smaller Changes
2556---------------
2557
2558A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2559map(None, seq1, seq2, ...) when the sequences have the same length;
2560i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2561the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002562zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002563
2564sys.version_info is a tuple (major, minor, micro, level, serial).
2565
2566Dictionaries have an odd new method, setdefault(key, default).
2567dict.setdefault(key, default) returns dict[key] if it exists; if not,
2568it sets dict[key] to default and returns that value. Thus:
2569
2570 dict.setdefault(key, []).append(item)
2571
2572does the same work as this common idiom:
2573
2574 if not dict.has_key(key):
2575 dict[key] = []
2576 dict[key].append(item)
2577
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002578There are two new variants of SyntaxError that are raised for
2579indentation-related errors: IndentationError and TabError.
2580
2581Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2582escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002583
2584The limits on the size of expressions and file in Python source code
2585have been raised from 2**16 to 2**32. Previous versions of Python
2586were limited because the maximum argument size the Python VM accepted
2587was 2**16. This limited the size of object constructor expressions,
2588e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2589limit was raised thanks to a patch by Charles Waldman that effectively
2590fixes the problem. It is now much more likely that you will be
2591limited by available memory than by an arbitrary limit in Python.
2592
2593The interpreter's maximum recursion depth can be modified by Python
2594programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2595limit is the maximum number of recursive calls that can be made by
2596Python code. The limit exists to prevent infinite recursion from
2597overflowing the C stack and causing a core dump. The default value is
25981000. The maximum safe value for a particular platform can be found
2599by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002600
2601New Modules and Packages
2602------------------------
2603
2604atexit - for registering functions to be called when Python exits.
2605
2606imputil - Greg Stein's alternative API for writing custom import
2607hooks.
2608
2609pyexpat - an interface to the Expat XML parser, contributed by Paul
2610Prescod.
2611
2612xml - a new package with XML support code organized (so far) in three
2613subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2614would fill a volume. There's a special feature whereby a
2615user-installed package named _xmlplus overrides the standard
2616xmlpackage; this is intended to give the XML SIG a hook to distribute
2617backwards-compatible updates to the standard xml package.
2618
2619webbrowser - a platform-independent API to launch a web browser.
2620
2621
Guido van Rossume905e952000-09-05 12:42:46 +00002622Changed Modules
2623---------------
2624
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002625array -- new methods for array objects: count, extend, index, pop, and
2626remove
2627
2628binascii -- new functions b2a_hex and a2b_hex that convert between
2629binary data and its hex representation
2630
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002631calendar -- Many new functions that support features including control
2632over which day of the week is the first day, returning strings instead
2633of printing them. Also new symbolic constants for days of week,
2634e.g. MONDAY, ..., SUNDAY.
2635
2636cgi -- FieldStorage objects have a getvalue method that works like a
2637dictionary's get method and returns the value attribute of the object.
2638
2639ConfigParser -- The parser object has new methods has_option,
2640remove_section, remove_option, set, and write. They allow the module
2641to be used for writing config files as well as reading them.
2642
2643ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002644optionally support the RFC 959 REST command.
2645
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002646gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002647
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002648httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2649the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002650
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002651locale -- implement getdefaultlocale for Win32 and Macintosh
2652
2653marshal -- no longer dumps core when marshaling deeply nested or
2654recursive data structures
2655
2656os -- new functions isatty, seteuid, setegid, setreuid, setregid
2657
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002658os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2659support under Unix.
2660
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002661os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002662
2663os.path -- fix semantics of os.path.commonprefix
2664
2665smtplib -- support for sending very long messages
2666
2667socket -- new function getfqdn()
2668
2669readline -- new functions to read, write and truncate history files.
2670The readline section of the library reference manual contains an
2671example.
2672
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002673select -- add interface to poll system call
2674
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002675shutil -- new copyfileobj function
2676
2677SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2678HTTP server.
2679
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002680Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002681
2682urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002683e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002684
2685whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002686
2687
2688Obsolete Modules
2689----------------
2690
2691None. However note that 1.6 made a whole slew of modules obsolete:
2692stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2693poly, zmod, strop, util, whatsound.
2694
2695
2696Changed, New, Obsolete Tools
2697----------------------------
2698
Tim Peters8b092332000-09-05 20:15:25 +00002699None.
Guido van Rossume905e952000-09-05 12:42:46 +00002700
2701
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002702C-level Changes
2703---------------
2704
2705Several cleanup jobs were carried out throughout the source code.
2706
2707All C code was converted to ANSI C; we got rid of all uses of the
2708Py_PROTO() macro, which makes the header files a lot more readable.
2709
2710Most of the portability hacks were moved to a new header file,
2711pyport.h; several other new header files were added and some old
2712header files were removed, in an attempt to create a more rational set
2713of header files. (Few of these ever need to be included explicitly;
2714they are all included by Python.h.)
2715
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002716Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002717and Win64, especially for the new Intel Itanium processor. Mick also
2718added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002719
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002720The C APIs to return an object's size have been update to consistently
2721use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2722previous versions, the abstract interfaces used PyXXX_Length and the
2723concrete interfaces used PyXXX_Size. The old names,
2724e.g. PyObject_Length, are still available for backwards compatibility
2725at the API level, but are deprecated.
2726
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002727The PyOS_CheckStack function has been implemented on Windows by
2728Fredrik Lundh. It prevents Python from failing with a stack overflow
2729on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002730
2731The GC changes resulted in creation of two new slots on object,
2732tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002733the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002734
2735The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002736C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002737
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002738PyErr_Format has been updated to automatically calculate the size of
2739the buffer needed to hold the formatted result string. This change
2740prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002741
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002742New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002743
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002744PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2745that are the same as their non-Ex counterparts except they take an
2746extra flag argument that tells them to close the file when done.
2747
2748XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002749
Tim Peters8b092332000-09-05 20:15:25 +00002750
2751Windows Changes
2752---------------
2753
2754New popen2/popen3/peopen4 in os module (see Changed Modules above).
2755
2756os.popen is much more usable on Windows 95 and 98. See Microsoft
2757Knowledge Base article Q150956. The Win9x workaround described there
2758is implemented by the new w9xpopen.exe helper in the root of your
2759Python installation. Note that Python uses this internally; it is not
2760a standalone program.
2761
2762Administrator privileges are no longer required to install Python
2763on Windows NT or Windows 2000. If you have administrator privileges,
2764Python's registry info will be written under HKEY_LOCAL_MACHINE.
2765Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002766under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002767uses of Python, but will prevent some advanced uses from working
2768(for example, running a Python script as an NT service, or possibly
2769from CGI).
2770
2771[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2772installer; instead, it installs the needed Tcl/Tk files directly in the
2773Python directory. If you already have a Tcl/Tk installation, this
2774wastes some disk space (about 4 Megs) but avoids problems with
2775conflicting Tcl/Tk installations, and makes it much easier for Python
2776to ensure that Tcl/Tk can find all its files.
2777
2778[This was new in 1.6] The Windows installer now installs by default in
2779\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2780
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002781
2782Updates to the changes between 1.5.2 and 1.6
2783--------------------------------------------
2784
2785The 1.6 NEWS file can't be changed after the release is done, so here
2786is some late-breaking news:
2787
2788New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2789and changes to getlocale() and setlocale().
2790
2791The new module is now enabled per default.
2792
2793It is not true that the encodings codecs cannot be used for normal
2794strings: the string.encode() (which is also present on 8-bit strings
2795!) allows using them for 8-bit strings too, e.g. to convert files from
2796cp1252 (Windows) to latin-1 or vice-versa.
2797
2798Japanese codecs are available from Tamito KAJIYAMA:
2799http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2800
2801
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002802======================================================================