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Tim Petersabf925f2001-09-28 21:53:42 +00001What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +00002Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +00003===========================
4
5Type/class unification and new-style classes
6
Guido van Rossum687ae002001-10-15 22:03:32 +00007- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +00008 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +00009 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000010 remains: the __dict__ of a new-style class is a read-only proxy; you
11 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000012 __defined__ attribute of new-style types no longer exists, for lack
13 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000014 future a __cache__ may be resurrected with a similar function, if I
15 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000016
Tim Peters1c9ca872001-10-04 06:43:12 +000017- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
18 always returned None, even when there was a class docstring).
19
20- doctest now finds and runs docstrings attached to new-style classes,
21 class methods, static methods, and properties.
22
Guido van Rossum9074ef62001-10-16 21:34:49 +000023Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +000024
Guido van Rossuma8bcf802001-10-15 15:53:58 +000025- A very subtle syntactical pitfall in list comprehensions was fixed.
26 For example: [a+b for a in 'abc', for b in 'def']. The comma in
27 this example is a mistake. Previously, this would silently let 'a'
28 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
29 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
30 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
31 Note that [a for a in <singleton>] is a convoluted way to say
32 [<singleton>] anyway, so it's not like any expressiveness is lost.
33
Guido van Rossum9074ef62001-10-16 21:34:49 +000034- getattr(obj, name, default) now only catches AttributeError, as
35 documented, rather than returning the default value for all
36 exceptions (which could mask bugs in a __getattr__ hook, for
37 example).
38
Fred Drake934d2a42001-10-18 18:18:06 +000039- Weak reference objects are now part of the core and offers a C API.
40 A bug which could allow a core dump when binary operations involved
Barry Warsawf6fb1712001-10-19 05:35:40 +000041 proxy reference has been fixed. weekref.ReferenceError is now a
42 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +000043
Guido van Rossum1c486092001-10-19 02:05:35 +000044- unicode(obj) now behaves more like str(obj), accepting arbitrary
45 objects, and calling a __unicode__ method if it exists.
46 unicode(obj, encoding) and unicode(obj, encoding, errors) still
47 require an 8-bit string argument.
48
Barry Warsawf6fb1712001-10-19 05:35:40 +000049- isinstance() now allows any object as the first argument and a
50 class, a type or something with a __bases__ tuple attribute for the
51 second argument. The second argument may also be a tuple of a
52 class, type, or something with __bases__, in which case isinstance()
53 will return true if the first argument is an instance of any of the
54 things contained in the second argument tuple. E.g.
55
56 isinstance(x, (A, B))
57
58 returns true if x is an instance of A or B.
59
Guido van Rossum9074ef62001-10-16 21:34:49 +000060Extension modules
61
62- thread.start_new_thread() now returns the thread ID (previously None).
63
Martin v. Löwis16dc7f42001-09-30 20:32:11 +000064- binascii has now two quopri support functions, a2b_qp and b2a_qp.
65
Guido van Rossumc524d952001-10-19 01:31:59 +000066- readline now supports setting the startup_hook and the
67 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +000068
Guido van Rossumc524d952001-10-19 01:31:59 +000069- os and posix supports chroot(), setgroups() and unsetenv() where
70 available. The stat(), fstat(), statvfs() and fstatvfs() functions
71 now return "pseudo-sequences" -- the various fields can now be
72 accessed as attributes (e.g. os.stat("/").st_mtime) but for
73 backwards compatibility they also behave as a fixed-length sequence.
74 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +000075 attributes.
76
77- time: localtime(), gmtime() and strptime() now return a
78 pseudo-sequence similar to the os.stat() return value, with
79 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +000080
Guido van Rossum9074ef62001-10-16 21:34:49 +000081- Decompression objects in the zlib module now accept an optional
82 second parameter to decompress() that specifies the maximum amount
83 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +000084
Jeremy Hyltoncb441432001-10-19 03:40:19 +000085- optional SSL support in the socket module now exports OpenSSL
86 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
87 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +000088 automatically seed its PRNG. Also, the keyfile and certfile
89 arguments to socket.ssl() are now optional.
90
91- posixmodule (and by extension, the os module on POSIX platforms) now
92 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +000093
Guido van Rossum9074ef62001-10-16 21:34:49 +000094Library
Guido van Rossum3c288632001-10-16 21:13:49 +000095
Tim Peters7402f792001-10-02 03:53:41 +000096- doctest now excludes functions and classes not defined by the module
97 being tested, thanks to Tim Hochberg.
98
Guido van Rossumc4b09b42001-10-04 10:19:00 +000099- profile now produces correct output in situations where an exception
100 raised in Python is cleared by C code (e.g. hasattr()). This used
101 to cause wrong output, including spurious claims of recursive
102 functions and attribution of time spent to the wrong function.
103
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000104 The code and documentation for the derived OldProfile and HotProfile
105 profiling classes was removed. The code hasn't worked for years (if
106 you tried to use them, they raised exceptions). OldProfile
107 intended to reproduce the behavior of the profiler Python used more
108 than 7 years ago, and isn't interesting anymore. HotProfile intended
109 to provide a faster profiler (but producing less information), and
110 that's a worthy goal we intend to meet via a different approach (but
111 without losing information).
112
Tim Peterscce092d2001-10-09 05:31:56 +0000113- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000114 a much better system-specific calibration constant. The constant can
115 now be specified in an instance constructor, or as a Profile class or
116 instance variable, instead of by editing profile.py's source code.
117 Calibration must still be done manually (see the docs for the profile
118 module).
119
120 Note that Profile.calibrate() must be overriden by subclasses.
121 Improving the accuracy required exploiting detailed knowledge of
122 profiler internals; the earlier method abstracted away the details
123 and measured a simplified model instead, but consequently computed
124 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000125
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000126- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000127 which indicates whether output is intended for the header 'Q'
128 encoding.
129
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000130- The SocketServer.ThreadingMixIn class now closes the request after
131 finish_request() returns. (Not when it errors out though.)
132
Barry Warsawf6fb1712001-10-19 05:35:40 +0000133- The nntplib module's NNTP.body() method has grown a `file' argument
134 to allow saving the message body to a file.
135
136- The email package has added a class email.Parser.HeaderParser which
137 only parses headers and does not recurse into the message's body.
138 Also, the module/class MIMEAudio has been added for representing
139 audio data (contributed by Anthony Baxter).
140
141- ftplib should be able to handle files > 2GB.
142
143- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
144 ON, and OFF.
145
Guido van Rossumed554f62001-10-02 23:15:37 +0000146Tools/Demos
147
148- Demo/dns was removed. It no longer serves any purpose; a package
149 derived from it is now maintained by Anthony Baxter, see
150 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000151
Barry Warsawf6fb1712001-10-19 05:35:40 +0000152- The freeze tool has been made more robust, and two new options have
153 been added: -X and -E.
154
Tim Petersabf925f2001-09-28 21:53:42 +0000155Build
156
Barry Warsawf6fb1712001-10-19 05:35:40 +0000157- configure will use CXX in LINKCC if CXX is used to build main() and
158 the system requires to link a C++ main using the C++ compiler.
159
Tim Petersabf925f2001-09-28 21:53:42 +0000160C API
161
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000162- The documentation for the tp_compare slot is updated to require that
163 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
164 not correct. This is not yet enforced but will be enforced in
165 Python 2.3; even later, we may use -2 to indicate errors and +2 for
166 "NotImplemented". Right now, -1 should be used for an error return.
167
Tim Petersd38b1c72001-09-30 05:09:37 +0000168- PyLong_AsLongLong() now accepts int (as well as long) arguments.
169 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
170 as long) arguments.
171
Guido van Rossum3c288632001-10-16 21:13:49 +0000172- PyThread_start_new_thread() now returns a long int giving the thread
173 ID, if one can be calculated; it returns -1 for error, 0 if no
174 thread ID is calculated (this is an incompatible change, but only
175 the thread module used this API). This code has only really been
176 tested on Linux and Windows; other platforms please beware (and
177 report any bugs or strange behavior).
178
Guido van Rossum1c486092001-10-19 02:05:35 +0000179- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
180 input.
181
Tim Petersabf925f2001-09-28 21:53:42 +0000182New platforms
183
184Tests
185
186Windows
187
Tim Peters04cf1d32001-10-09 22:39:40 +0000188- Installer: If you install IDLE, and don't disable file-extension
189 registration, a new "Edit with IDLE" context (right-click) menu entry
190 is created for .py and .pyw files.
191
Tim Peters1ce3cf72001-10-01 17:58:40 +0000192- The signal module now supports SIGBREAK on Windows, thanks to Steven
193 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
194 action remains to call Win32 ExitProcess(). This can be changed via
195 signal.signal(). For example:
196
197 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
198 # (SIGINT) behavior.
199 import signal
200 signal.signal(signal.SIGBREAK,
201 signal.default_int_handler)
202
203 try:
204 while 1:
205 pass
206 except KeyboardInterrupt:
207 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
208 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
209 # program without the possibility for any Python-level cleanup).
210 print "Clean exit"
211
Tim Petersabf925f2001-09-28 21:53:42 +0000212
Tim Petersb07352e2001-09-08 01:25:47 +0000213What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000214Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000215===========================
216
Guido van Rossum808eea72001-09-25 04:15:41 +0000217Type/class unification and new-style classes
218
219- pydoc and inspect are now aware of new-style classes;
220 e.g. help(list) at the interactive prompt now shows proper
221 documentation for all operations on list objects.
222
223- Applications using Jim Fulton's ExtensionClass module can now safely
224 be used with Python 2.2. In particular, Zope 2.4.1 now works with
225 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
226 examples also work again. It is hoped that Gtk and Boost also work
227 with 2.2a4 and beyond. (If you can confirm this, please write
228 webmaster@python.org; if there are still problems, please open a bug
229 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000230
Tim Peters66c1a522001-09-24 21:17:50 +0000231- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
232 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
233 in the constructed property object. fget, fset and fdel weren't
234 discoverable from Python in 2.2a3. __doc__ is new, and allows to
235 associate a docstring with a property.
236
Guido van Rossum808eea72001-09-25 04:15:41 +0000237- Comparison overloading is now more completely implemented. For
238 example, a str subclass instance can properly be compared to a str
239 instance, and it can properly overload comparison. Ditto for most
240 other built-in object types.
241
242- The repr() of new-style classes has changed; instead of <type
243 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
244 *except* for built-in types, which are still rendered as <type
245 'Foo'> (to avoid upsetting existing code that might parse or
246 otherwise rely on repr() of certain type objects).
247
248- The repr() of new-style objects is now always <Foo object at XXX>;
249 previously, it was sometimes <Foo instance at XXX>.
250
251- For new-style classes, what was previously called __getattr__ is now
252 called __getattribute__. This method, if defined, is called for
253 *every* attribute access. A new __getattr__ hook mor similar to the
254 one in classic classes is defined which is called only if regular
255 attribute access raises AttributeError; to catch *all* attribute
256 access, you can use __getattribute__ (for new-style classes). If
257 both are defined, __getattribute__ is called first, and if it raises
258 AttributeError, __getattr__ is called.
259
260- The __class__ attribute of new-style objects can be assigned to.
261 The new class must have the same C-level object layout as the old
262 class.
263
264- The builtin file type can be subclassed now. In the usual pattern,
265 "file" is the name of the builtin type, and file() is a new builtin
266 constructor, with the same signature as the builtin open() function.
267 file() is now the preferred way to open a file.
268
269- Previously, __new__ would only see sequential arguments passed to
270 the type in a constructor call; __init__ would see both sequential
271 and keyword arguments. This made no sense whatsoever any more, so
272 now both __new__ and __init__ see all arguments.
273
274- Previously, hash() applied to an instance of a subclass of str or
275 unicode always returned 0. This has been repaired.
276
277- Previously, an operation on an instance of a subclass of an
278 immutable type (int, long, float, complex, tuple, str, unicode),
279 where the subtype didn't override the operation (and so the
280 operation was handled by the builtin type), could return that
281 instance instead a value of the base type. For example, if s was of
282 a str sublass type, s[:] returned s as-is. Now it returns a str
283 with the same value as s.
284
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000285- Provisional support for pickling new-style objects has been added.
286
Guido van Rossum808eea72001-09-25 04:15:41 +0000287Core
288
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000289- file.writelines() now accepts any iterable object producing strings.
290
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000291- PyUnicode_FromEncodedObject() now works very much like
292 PyObject_Str(obj) in that it tries to use __str__/tp_str
293 on the object if the object is not a string or buffer. This
294 makes unicode() behave like str() when applied to non-string/buffer
295 objects.
296
Martin v. Löwis2777c022001-09-19 13:47:32 +0000297- PyFile_WriteObject now passes Unicode object to the file's write
298 method. As a result, all file-like object which may be the target
299 of a print statement must support Unicode objects, i.e. they must
300 at least convert them into ASCII strings.
301
Guido van Rossum624c8af2001-09-18 15:21:04 +0000302- Thread scheduling on Solaris should be improved; it is no longer
303 necessary to insert a small sleep at the start of a thread in order
304 to let other runnable threads be scheduled.
305
Tim Petersb07352e2001-09-08 01:25:47 +0000306Library
307
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000308- StringIO.StringIO instances and cStringIO.StringIO instances support
309 read character buffer compatible objects for their .write() methods.
310 These objects are converted to strings and then handled as such
311 by the instances.
312
Barry Warsaw2f600732001-09-24 04:28:10 +0000313- The "email" package has been added. This is basically a port of the
314 mimelib package <http://sf.net/projects/mimelib> with API changes
315 and some implementations updated to use iterators and generators.
316
Tim Peters8a9c2842001-09-22 21:30:22 +0000317- difflib.ndiff() and difflib.Differ.compare() are generators now. This
318 restores the ability of Tools/scripts/ndiff.py to start producing output
319 before the entire comparison is complete.
320
Barry Warsaw58b072d2001-09-22 04:44:21 +0000321- StringIO.StringIO instances and cStringIO.StringIO instances support
322 iteration just like file objects (i.e. their .readline() method is
323 called for each iteration until it returns an empty string).
324
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000325- The codecs module has grown four new helper APIs to access
326 builtin codecs: getencoder(), getdecoder(), getreader(),
327 getwriter().
328
Guido van Rossum624c8af2001-09-18 15:21:04 +0000329- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
330 simplifies writing XML RPC servers.
331
Barry Warsaw647d5e82001-09-28 17:01:02 +0000332- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000333 after interpretation of symbolic links. On non-Unix systems, this
334 is an alias for os.path.abspath().
335
Tim Peters16a77ad2001-09-08 04:00:12 +0000336- operator.indexOf() (PySequence_Index() in the C API) now works with any
337 iterable object.
338
Guido van Rossum624c8af2001-09-18 15:21:04 +0000339- smtplib now supports various authentication and security features of
340 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000341
Guido van Rossum624c8af2001-09-18 15:21:04 +0000342- hmac: a new module implementing keyed hashing for message
343 authentication.
344
345- mimetypes now recognizes more extensions and file types. At the
346 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000347
Guido van Rossum624c8af2001-09-18 15:21:04 +0000348- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000349 Python 2.2 bytecode generation. It has also been promoted from a
350 Tool to a standard library package. (Tools/compiler still exists as
351 a sample driver.)
352
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000353Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000354
Tim Petersb07352e2001-09-08 01:25:47 +0000355Build
356
Guido van Rossum624c8af2001-09-18 15:21:04 +0000357- Large file support (LFS) is now automatic when the platform supports
358 it; no more manual configuration tweaks are needed. On Linux, at
359 least, it's possible to have a system whose C library supports large
360 files but whose kernel doesn't; in this case, large file support is
361 still enabled but doesn't do you any good unless you upgrade your
362 kernel or share your Python executable with another system whose
363 kernel has large file support.
364
365- The configure script now supplies plausible defaults in a
366 cross-compilation environment. This doesn't mean that the supplied
367 values are always correct, or that cross-compilation now works
368 flawlessly -- but it's a first step (and it shuts up most of
369 autoconf's warnings about AC_TRY_RUN).
370
371- The Unix build is now a bit less chatty, courtesy of the parser
372 generator. The build is completely silent (except for errors) when
373 using "make -s", thanks to a -q option to setup.py.
374
Tim Petersb07352e2001-09-08 01:25:47 +0000375C API
376
Guido van Rossum624c8af2001-09-18 15:21:04 +0000377- The "structmember" API now supports some new flag bits to deny read
378 and/or write access to attributes in restricted execution mode.
379
Tim Petersb07352e2001-09-08 01:25:47 +0000380New platforms
381
Guido van Rossum624c8af2001-09-18 15:21:04 +0000382- Compaq's iPAQ handheld, running the "familiar" Linux distribution
383 (http://familiar.handhelds.org).
384
Tim Petersb07352e2001-09-08 01:25:47 +0000385Tests
386
Tim Peters8a9c2842001-09-22 21:30:22 +0000387- The "classic" standard tests, which work by comparing stdout to
388 an expected-output file under Lib/test/output/, no longer stop at
389 the first mismatch. Instead the test is run to completion, and a
390 variant of ndiff-style comparison is used to report all differences.
391 This is much easier to understand than the previous style of reporting.
392
393- The unittest-based standard tests now use regrtest's test_main()
394 convention, instead of running as a side-effect of merely being
395 imported. This allows these tests to be run in more natural and
396 flexible ways as unittests, outside the regrtest framework.
397
398- regrtest.py is much better integrated with unittest and doctest now,
399 especially in regard to reporting errors.
400
Tim Petersb07352e2001-09-08 01:25:47 +0000401Windows
402
Guido van Rossum624c8af2001-09-18 15:21:04 +0000403- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000404 that support it (NTFS under Windows 2000). See "What's New in
405 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000406
Tim Petersb07352e2001-09-08 01:25:47 +0000407
Tim Petersedc99312001-08-22 21:36:50 +0000408What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000409Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000410===========================
411
412Core
413
Tim Peters9fffa3e2001-09-04 05:14:19 +0000414- Conversion of long to float now raises OverflowError if the long is too
415 big to represent as a C double.
416
Tim Peters32f453e2001-09-03 08:35:41 +0000417- The 3-argument builtin pow() no longer allows a third non-None argument
418 if either of the first two arguments is a float, or if both are of
419 integer types and the second argument is negative (in which latter case
420 the arguments are converted to float, so this is really the same
421 restriction).
422
Tim Peters5d2b77c2001-09-03 05:47:38 +0000423- The builtin dir() now returns more information, and sometimes much
424 more, generally naming all attributes of an object, and all attributes
425 reachable from the object via its class, and from its class's base
426 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
427 an empty list. In 2.2a3,
428
429 >>> dir([])
430 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
431 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
432 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
433 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
434 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
435 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
436 'reverse', 'sort']
437
438 dir(module) continues to return only the module's attributes, though.
439
Tim Petersbdee63f2001-09-02 03:40:59 +0000440- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000441 than raising OverflowError. This is a partial implementation of PEP
442 237. You can use -Wdefault::OverflowWarning to enable a warning for
443 this situation, and -Werror::OverflowWarning to revert to the old
444 OverflowError exception.
445
Guido van Rossum61c345f2001-09-04 03:26:15 +0000446- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000447 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000448 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
449 -Qold, meaning the / operator has its classic meaning and no
450 warnings are issued. Using -Qwarn issues a run-time warning about
451 all uses of classic division for int and long arguments; -Qwarnall
452 also warns about classic division for float and complex arguments
453 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
454 new division by default, but only in the __main__ module. You can
455 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
456 __main__ module new division, and warns about classic division
457 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000458
Tim Petersbdee63f2001-09-02 03:40:59 +0000459- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000460 long, float, str, unicode, and tuple. (The types complex, list and
461 dictionary can also be subclassed; this was introduced earlier.)
462 Note that restrictions apply when subclassing immutable built-in
463 types: you can only affect the value of the instance by overloading
464 __new__. You can add mutable attributes, and the subclass instances
465 will have a __dict__ attribute, but you cannot change the "value"
466 (as implemented by the base class) of an immutable subclass instance
467 once it is created.
468
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000469- The dictionary constructor now takes an optional argument, a
470 mapping-like object, and initializes the dictionary from its
471 (key, value) pairs.
472
Tim Petersbdee63f2001-09-02 03:40:59 +0000473- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000474 "cooperative super calls" in a multiple inheritance setting. For an
475 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
476
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000477- A new built-in type, property, has been added. This enables the
478 creation of "properties". These are attributes implemented by
479 getter and setter functions (or only one of these for read-only or
480 write-only attributes), without the need to override __getattr__.
481 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000482
Tim Petersbdee63f2001-09-02 03:40:59 +0000483- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000484 liberalized, to allow leading zeroes. Examples of literals now
485 legal that were SyntaxErrors before:
486
487 00.0 0e3 0100j 07.5 00000000000000000008.
488
Tim Petersbdee63f2001-09-02 03:40:59 +0000489- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000490 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
491
Tim Petersedc99312001-08-22 21:36:50 +0000492Library
493
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000494- telnetlib includes symbolic names for the options, and support for
495 setting an option negotiation callback.
496
Tim Petersa40c7932001-09-05 22:36:56 +0000497- The new C standard no longer requires that math libraries set errno to
498 ERANGE on overflow. For platform libraries that exploit this new
499 freedom, Python's overflow-checking was wholly broken. A new overflow-
500 checking scheme attempts to repair that, but may not be reliable on all
501 platforms (C doesn't seem to provide anything both useful and portable
502 in this area anymore).
503
Martin v. Löwis44f86962001-09-05 13:44:54 +0000504- Asynchronous timeout actions are available through the new class
505 threading.Timer.
506
Tim Peters78526162001-09-05 00:53:45 +0000507- math.log and math.log10 now return sensible results for even huge
508 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
509
Tim Petersbdee63f2001-09-02 03:40:59 +0000510- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000511 currently held. See the docs for the imp module.
512
Tim Petersbdee63f2001-09-02 03:40:59 +0000513- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000514 dumps containing ints written on platforms where Python ints are 8 bytes.
515 When read on a box where Python ints are 4 bytes, such values are
516 converted to Python longs.
517
Tim Petersbdee63f2001-09-02 03:40:59 +0000518- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000519 code objects is no longer allowed. This plugs a security hole.
520
Steve Purcell6091cd62001-09-06 16:05:17 +0000521- unittest.TestResult instances no longer store references to tracebacks
522 generated by test failures. This prevents unexpected dangling references
523 to objects that should be garbage collected between tests.
524
Tim Petersedc99312001-08-22 21:36:50 +0000525Tools
526
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000527- Tools/scripts/fixdiv.py has been added which can be used to fix
528 division operators as per PEP 238.
529
Tim Petersedc99312001-08-22 21:36:50 +0000530Build
531
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000532- If you are an adventurous person using Mac OS X you may want to look at
533 Mac/OSX. There is a Makefile there that will build Python as a real Mac
534 application, which can be used for experimenting with Carbon or Cocoa.
535 Discussion of this on pythonmac-sig, please.
536
Tim Peters7eea37e2001-09-04 22:08:56 +0000537C API
538
539- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000540
Tim Peters9fffa3e2001-09-04 05:14:19 +0000541- Note that PyLong_AsDouble can fail! This has always been true, but no
542 callers checked for it. It's more likely to fail now, because overflow
543 errors are properly detected now. The proper way to check:
544
545 double x = PyLong_AsDouble(some_long_object);
546 if (x == -1.0 && PyErr_Occurred()) {
547 /* The conversion failed. */
548 }
549
Tim Petersbdee63f2001-09-02 03:40:59 +0000550- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000551 compile but will not participate in GC. To upgrade an extension
552 module:
553
554 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000555
Neil Schemenauer4042c692001-08-30 15:38:01 +0000556 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
557 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000558
Neil Schemenauer4042c692001-08-30 15:38:01 +0000559 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
560 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000561
Neil Schemenauer4042c692001-08-30 15:38:01 +0000562 - remove PyGC_HEAD_SIZE from object size calculations
563
564 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
565
Tim Petersbdee63f2001-09-02 03:40:59 +0000566- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000567 These can be used safely to construct string objects from a
568 sprintf-style format string (similar to the format string supported
569 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000570
Tim Petersedc99312001-08-22 21:36:50 +0000571New platforms
572
Tim Petersb7da0902001-09-02 23:01:43 +0000573- Stephen Hansen contributed patches sufficient to get a clean compile
574 under Borland C (Windows), but he reports problems running it and ran
575 out of time to complete the port. Volunteers? Expect a MemoryError
576 when importing the types module; this is probably shallow, and
577 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000578
Tim Petersedc99312001-08-22 21:36:50 +0000579Tests
580
581Windows
582
Tim Peters6e13a562001-09-06 00:32:15 +0000583- Large file support is now enabled on Win32 platforms as well as on
584 Win64. This means that, for example, you can use f.tell() and f.seek()
585 to manipulate files larger than 2 gigabytes (provided you have enough
586 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000587 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
588 filesize limit, and large file support makes no difference there.
589 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
590 NTFS has no practical limit on file size, and files of any size can be
591 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000592
Tim Petersbdee63f2001-09-02 03:40:59 +0000593- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000594 points to command.com (patch from Brian Quinlan).
595
Tim Petersedc99312001-08-22 21:36:50 +0000596
Tim Peters20f51a72001-07-21 02:31:40 +0000597What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000598Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000599===========================
600
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000601Build
602
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000603- Tim Peters developed a brand new Windows installer using Wise 8.1,
604 generously donated to us by Wise Solutions.
605
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000606- configure supports a new option --enable-unicode, with the values
607 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
608 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000609
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000610- A new configure option --enable-framework builds a Mac OS X framework,
611 which "make frameworkinstall" will install. This provides a starting
612 point for more mac-like functionality, join pythonmac-sig@python.org
613 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000614
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000615- The NeXT platform is no longer supported.
616
617- The `new' module is now statically linked.
618
Tim Peters0afb6092001-08-15 06:06:44 +0000619Tools
620
621- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000622 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000623 the module docstring for details.
624
Tim Peters20f51a72001-07-21 02:31:40 +0000625Tests
626
Tim Peters5e824c32001-08-12 22:25:01 +0000627- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000628 platforms, allowing to give clearer test result output. regrtest
629 also has optional --use/-u switch to run normally disabled tests
630 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000631
Tim Peters20f51a72001-07-21 02:31:40 +0000632- Several new tests in the standard test suite, with special thanks to
633 Nick Mathewson.
634
635Core
636
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000637- The floor division operator // has been added as outlined in PEP
638 238. The / operator still provides classic division (and will until
639 Python 3.0) unless "from __future__ import division" is included, in
640 which case the / operator will provide true division. The operator
641 module provides truediv() and floordiv() functions. Augmented
642 assignment variants are included, as are the equivalent overloadable
643 methods and C API methods. See the PEP for a full discussion:
644 <http://python.sf.net/peps/pep-0238.html>
645
Tim Peters6cd6a822001-08-17 22:11:27 +0000646- Future statements are now effective in simulated interactive shells
647 (like IDLE). This should "just work" by magic, but read Michael
648 Hudson's "Future statements in simulated shells" PEP 264 for full
649 details: <http://python.sf.net/peps/pep-0264.html>.
650
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000651- The type/class unification (PEP 252-253) was integrated into the
652 trunk and is not so tentative any more (the exact specification of
653 some features is still tentative). A lot of work has done on fixing
654 bugs and adding robustness and features (performance still has to
655 come a long way).
656
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000657- Warnings about a mismatch in the Python API during extension import
658 now use the Python warning framework (which makes it possible to
659 write filters for these warnings).
660
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000661- A function's __dict__ (aka func_dict) will now always be a
662 dictionary. It used to be possible to delete it or set it to None,
663 but now both actions raise TypeErrors. It is still legal to set it
664 to a dictionary object. Getting func.__dict__ before any attributes
665 have been assigned now returns an empty dictionary instead of None.
666
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000667- A new command line option, -E, was added which disables the use of
668 all environment variables, or at least those that are specifically
669 significant to Python. Usually those have a name starting with
670 "PYTHON". This was used to fix a problem where the tests fail if
671 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
672 older distribution.
673
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000674Library
675
Tim Peters5e824c32001-08-12 22:25:01 +0000676- New class Differ and new functions ndiff() and restore() in difflib.py.
677 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000678 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000679
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000680- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
681 value using the minimal quoting required for the value; more
682 reliable than using xml.sax.saxutils.escape() for attribute values.
683
684- Readline completion support for cmd.Cmd was added.
685
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000686- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
687
688- Added function threading.BoundedSemaphore()
689
690- Added Ka-Ping Yee's cgitb.py module.
691
692- The `new' module now exposes the CO_xxx flags.
693
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000694New platforms
695
696C API
697
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000698- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
699 which provide a cross-platform implementations for the
700 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
701 the standard sprintf() and vsprintf() C lib APIs, these versions
702 apply bounds checking on the used buffer which enhances protection
703 against buffer overruns.
704
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000705- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000706 and extensions using different Unicode widths is rendered next to
707 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000708 will result in an ImportError. Unicode extensions writers must make
709 sure to check the Unicode width compatibility in their extensions by
710 using at least one of the mangled Unicode APIs in the extension.
711
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000712- Two new flags METH_NOARGS and METH_O are available in method definition
713 tables to simplify implementation of methods with no arguments and a
714 single untyped argument. Calling such methods is more efficient than
715 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
716 deprecated.
717
Tim Petersc1731372001-08-04 08:12:36 +0000718Windows
719
720- "import module" now compiles module.pyw if it exists and nothing else
721 relevant is found.
722
Tim Peters20f51a72001-07-21 02:31:40 +0000723
Guido van Rossum55a78992001-07-17 17:22:32 +0000724What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000725===========================
726
727Core
Tim Petersa814db52001-05-14 07:05:58 +0000728
Tim Peters6d6c1a32001-08-02 04:15:00 +0000729- TENTATIVELY, a large amount of code implementing much of what's
730 described in PEP 252 (Making Types Look More Like Classes) and PEP
731 253 (Subtyping Built-in Types) was added. This will be released
732 with Python 2.2a1. Documentation will be provided separately
733 through http://www.python.org/2.2/. The purpose of releasing this
734 with Python 2.2a1 is to test backwards compatibility. It is
735 possible, though not likely, that a decision is made not to release
736 this code as part of 2.2 final, if any serious backwards
737 incompapatibilities are found during alpha testing that cannot be
738 repaired.
739
Guido van Rossum55a78992001-07-17 17:22:32 +0000740- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000741 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000742 more 'yield' statements. See PEP 255. Since this adds a new
743 keyword to the language, this feature must be enabled by including a
744 future statement: "from __future__ import generators" (see PEP 236).
745 Generators will become a standard feature in a future release
746 (probably 2.3). Without this future statement, 'yield' remains an
747 ordinary identifier, but a warning is issued each time it is used.
748 (These warnings currently don't conform to the warnings framework of
749 PEP 230; we intend to fix this in 2.2a2.)
750
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000751- The UTF-16 codec was modified to be more RFC compliant. It will now
752 only remove BOM characters at the start of the string and then
753 only if running in native mode (UTF-16-LE and -BE won't remove a
754 leading BMO character).
755
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000756- Strings now have a new method .decode() to complement the already
757 existing .encode() method. These two methods provide direct access
758 to the corresponding decoders and encoders of the registered codecs.
759
760 To enhance the usability of the .encode() method, the special
761 casing of Unicode object return values was dropped (Unicode objects
762 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000763
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000764 Both methods will now return whatever the codec in charge of the
765 requested encoding returns as object, e.g. Unicode codecs will
766 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
767 will return u"äöü"). This enables codec writer to create codecs
768 for various simple to use conversions.
769
770 New codecs were added to demonstrate these new features (the .encode()
771 and .decode() columns indicate the type of the returned objects):
772
773 Name | .encode() | .decode() | Description
774 ----------------------------------------------------------------------
775 uu | string | string | UU codec (e.g. for email)
776 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000777 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000778 zlib | string | string | zlib compression
779 hex | string | string | 2-byte hex codec
780 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
781
Mark Hammond2a0af792001-05-14 03:09:36 +0000782- Some operating systems now support the concept of a default Unicode
783 encoding for file system operations. Notably, Windows supports 'mbcs'
784 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000785 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000786 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000787
788 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000789 functions that return filenames (such as os.listdir()) to return Python
790 string objects pre-encoded using the default file system encoding for
791 the platform. As this encoding is likely to be different from Python's
792 default encoding, converting this name to a Unicode object before passing
793 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000794 would attempt to use its default encoding (generally ASCII) rather than
795 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000796
Tim Petersa814db52001-05-14 07:05:58 +0000797 In general, this change simply removes surprises when working with
798 Unicode and the file system, making these operations work as you expect,
799 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000800 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000801
Tim Peters61dff2b2001-05-08 15:43:37 +0000802- Float (and complex) literals in source code were evaluated to full
803 precision only when running from a .py file; the same code loaded from a
804 .pyc (or .pyo) file could suffer numeric differences starting at about the
805 12th significant decimal digit. For example, on a machine with IEEE-754
806 floating arithmetic,
807
808 x = 9007199254740992.0
809 print long(x)
810
811 printed 9007199254740992 if run directly from .py, but 9007199254740000
812 if from a compiled (.pyc or .pyo) file. This was due to marshal using
813 str(float) instead of repr(float) when building code objects. marshal
814 now uses repr(float) instead, which should reproduce floats to full
815 machine precision (assuming the platform C float<->string I/O conversion
816 functions are of good quality).
817
818 This may cause floating-point results to change in some cases, and
819 usually for the better, but may also cause numerically unstable
820 algorithms to break.
821
Tim Peters2f228e72001-05-13 00:19:31 +0000822- The implementation of dicts suffers fewer collisions, which has speed
823 benefits. However, the order in which dict entries appear in dict.keys(),
824 dict.values() and dict.items() may differ from previous releases for a
825 given dict. Nothing is defined about this order, so no program should
826 rely on it. Nevertheless, it's easy to write test cases that rely on the
827 order by accident, typically because of printing the str() or repr() of a
828 dict to an "expected results" file. See Lib/test/test_support.py's new
829 sortdict(dict) function for a simple way to display a dict in sorted
830 order.
831
Tim Peters7a3bfc32001-06-12 01:22:22 +0000832- Many other small changes to dicts were made, resulting in faster
833 operation along the most common code paths.
834
Guido van Rossum10315822001-05-01 20:54:30 +0000835- Dictionary objects now support the "in" operator: "x in dict" means
836 the same as dict.has_key(x).
837
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000838- The update() method of dictionaries now accepts generic mapping
839 objects. Specifically the argument object must support the .keys()
840 and __getitem__() methods. This allows you to say, for example,
841 {}.update(UserDict())
842
Guido van Rossum10315822001-05-01 20:54:30 +0000843- Iterators were added; this is a generalized way of providing values
844 to a for loop. See PEP 234. There's a new built-in function iter()
845 to return an iterator. There's a new protocol to get the next value
846 from an iterator using the next() method (in Python) or the
847 tp_iternext slot (in C). There's a new protocol to get iterators
848 using the __iter__() method (in Python) or the tp_iter slot (in C).
849 Iterating (i.e. a for loop) over a dictionary generates its keys.
850 Iterating over a file generates its lines.
851
Tim Petersf553f892001-05-01 20:45:31 +0000852- The following functions were generalized to work nicely with iterator
853 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000854 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000855 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
856 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000857 join() method of strings
858 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000859 'x in y' and 'x not in y' (PySequence_Contains() in C API)
860 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000861 right-hand side of assignment statements with multiple targets, such as
862 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000863
Tim Petersd85e1022001-05-11 21:51:48 +0000864- Accessing module attributes is significantly faster (for example,
865 random.random or os.path or yourPythonModule.yourAttribute).
866
Tim Peterse63415e2001-05-08 04:38:29 +0000867- Comparing dictionary objects via == and != is faster, and now works even
868 if the keys and values don't support comparisons other than ==.
869
Tim Peters95bf9392001-05-10 08:32:44 +0000870- Comparing dictionaries in ways other than == and != is slower: there were
871 insecurities in the dict comparison implementation that could cause Python
872 to crash if the element comparison routines for the dict keys and/or
873 values mutated the dicts. Making the code bulletproof slowed it down.
874
Tim Peterseb28ef22001-06-02 05:27:19 +0000875- Collisions in dicts are resolved via a new approach, which can help
876 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000877 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000878 faster now. Thanks to Christian Tismer for pointing out the cause and
879 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000880
Tim Peters52e155e2001-06-16 05:42:57 +0000881- repr() is much faster for large containers (dict, list, tuple).
882
883
Tim Petersa814db52001-05-14 07:05:58 +0000884Library
885
Fred Drake960fdf92001-07-20 18:38:26 +0000886- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
887 were added to the string module. These a locale-indenpendent
888 constants, unlike letters, lowercase, and uppercase. These are now
889 use in appropriate locations in the standard library.
890
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000891- The flags used in dlopen calls can now be configured using
892 sys.setdlopenflags and queried using sys.getdlopenflags.
893
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000894- Fredrik Lundh's xmlrpclib is now a standard library module. This
895 provides full client-side XML-RPC support. In addition,
896 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
897 one asyncore-based). Thanks to Eric Raymond for the documentation.
898
Guido van Rossum643d3912001-07-05 14:46:25 +0000899- The xrange() object is simplified: it no longer supports slicing,
900 repetition, comparisons, efficient 'in' checking, the tolist()
901 method, or the start, stop and step attributes. See PEP 260.
902
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000903- A new function fnmatch.filter to filter lists of file names was added.
904
Barry Warsawffd674d2001-05-22 16:00:10 +0000905- calendar.py uses month and day names based on the current locale.
906
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000907- strop is now *really* obsolete (this was announced before with 1.6),
908 and issues DeprecationWarning when used (except for the four items
909 that are still imported into string.py).
910
Tim Petersa814db52001-05-14 07:05:58 +0000911- Cookie.py now sorts key+value pairs by key in output strings.
912
913- pprint.isrecursive(object) didn't correctly identify recursive objects.
914 Now it does.
915
Tim Peters95b3f782001-05-14 18:39:41 +0000916- pprint functions now much faster for large containers (tuple, list, dict).
917
Tim Peters7b9542a2001-06-10 23:40:19 +0000918- New 'q' and 'Q' format codes in the struct module, corresponding to C
919 types "long long" and "unsigned long long" (on Windows, __int64). In
920 native mode, these can be used only when the platform C compiler supports
921 these types (when HAVE_LONG_LONG is #define'd by the Python config
922 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000923 In standard mode, 'q' and 'Q' are supported on all platforms, and are
924 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000925
Guido van Rossum83213cc2001-06-12 16:48:52 +0000926- The site module installs a new built-in function 'help' that invokes
927 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
928 it displays a message reminding the user to use 'help()' or
929 'help(object)'.
930
Tim Petersa814db52001-05-14 07:05:58 +0000931Tests
932
933- New test_mutants.py runs dict comparisons where the key and value
934 comparison operators mutute the dicts randomly during comparison. This
935 rapidly causes Python to crash under earlier releases (not for the faint
936 of heart: it can also cause Win9x to freeze or reboot!).
937
938- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000939 pprint.isreadable() return sensible results. Also verifies that simple
940 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000941
Tim Peters4324aa32001-05-28 22:30:08 +0000942C API
943
944- Removed the unused last_is_sticky argument from the internal
945 _PyTuple_Resize(). If this affects you, you were cheating.
946
947
Guido van Rossum55a78992001-07-17 17:22:32 +0000948======================================================================
949
950
Guido van Rossumffe13be2001-04-16 18:46:45 +0000951What's New in Python 2.1 (final)?
952=================================
953
954We only changed a few things since the last release candidate, all in
955Python library code:
956
957- A bug in the locale module was fixed that affected locales which
958 define no grouping for numeric formatting.
959
960- A few bugs in the weakref module's implementations of weak
961 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
962 and the test suite was updated to check for these bugs.
963
964- An old bug in the os.path.walk() function (introduced in Python
965 2.0!) was fixed: a non-existent file would cause an exception
966 instead of being ignored.
967
968- Fixed a few bugs in the new symtable module found by Neil Norwitz's
969 PyChecker.
970
971
Guido van Rossum5b08f132001-04-16 02:05:23 +0000972What's New in Python 2.1c2?
973===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000974
Guido van Rossum5b08f132001-04-16 02:05:23 +0000975A flurry of small changes, and one showstopper fixed in the nick of
976time made it necessary to release another release candidate. The list
977here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000978
Guido van Rossum5b08f132001-04-16 02:05:23 +0000979Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000980
Guido van Rossum5b08f132001-04-16 02:05:23 +0000981- Tim discovered a nasty bug in the dictionary code, caused by
982 PyDict_Next() calling dict_resize(), and the GC code's use of
983 PyDict_Next() violating an assumption in dict_items(). This was
984 fixed with considerable amounts of band-aid, but the net effect is a
985 saner and more robust implementation.
986
987- Made a bunch of symbols static that were accidentally global.
988
989Build and Ports
990
991- The setup.py script didn't check for a new enough version of zlib
992 (1.1.3 is needed). Now it does.
993
994- Changed "make clean" target to also remove shared libraries.
995
996- Added a more general warning about the SGI Irix optimizer to README.
997
998Library
999
1000- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1001 omitted the slash between host and file.html.
1002
1003- The mailbox module's _Mailbox class contained a completely broken
1004 and undocumented seek() method. Ripped it out.
1005
1006- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1007 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1008
1009- Fixed a few last-minute bugs in unittest.
1010
1011Extensions
1012
1013- Reverted the patch to the OpenSSL code in socketmodule.c to support
1014 RAND_status() and the EGD, and the subsequent patch that tried to
1015 fix it for pre-0.9.5 versions; the problem with the patch is that on
1016 some systems it issues a warning whenever socket is imported, and
1017 that's unacceptable.
1018
1019Tests
1020
1021- Fixed the pickle tests to work with "import test.test_pickle".
1022
1023- Tweaked test_locale.py to actually run the test Windows.
1024
1025- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1026 not "wb" (which is not a valid mode at all).
1027
1028- Fix pstats browser crashes. Import readline if it exists to make
1029 the user interface nicer.
1030
1031- Add "import thread" to the top of test modules that import the
1032 threading module (test_asynchat and test_threadedtempfile). This
1033 prevents test failures caused by a broken threading module resulting
1034 from a previously caught failed import.
1035
1036- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1037 needed on some platforms (e.g. Solaris 8) when the tests are run
1038 twice in succession.
1039
1040- Skip rather than fail test_sunaudiodev if no audio device is found.
1041
1042
1043What's New in Python 2.1c1?
1044===========================
1045
1046This list was significantly updated when 2.1c2 was released; the 2.1c1
1047release didn't mention most changes that were actually part of 2.1c1:
1048
1049Legal
1050
1051- Copyright was assigned to the Python Software Foundation (PSF) and a
1052 PSF license (very similar to the CNRI license) was added.
1053
1054- The CNRI copyright notice was updated to include 2001.
1055
1056Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001057
Guido van Rossumc9932722001-04-12 02:31:27 +00001058- After a public outcry, assignment to __debug__ is no longer illegal;
1059 instead, a warning is issued. It will become illegal in 2.2.
1060
Guido van Rossum5b08f132001-04-16 02:05:23 +00001061- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1062 "%#x" now always prepends "0x", even if the value is zero.
1063
1064- Fixed some nits in the bytecode compiler.
1065
1066- Fixed core dumps when calling certain kinds of non-functions.
1067
1068- Fixed various core dumps caused by reference count bugs.
1069
1070Build and Ports
1071
1072- Use INSTALL_SCRIPT to install script files.
1073
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001074- New port: SCO Unixware 7, by Billy G. Allie.
1075
Guido van Rossum5b08f132001-04-16 02:05:23 +00001076- Updated RISCOS port.
1077
1078- Updated BeOS port and notes.
1079
1080- Various other porting problems resolved.
1081
1082Library
1083
1084- The TERMIOS and SOCKET modules are now truly obsolete and
1085 unnecessary. Their symbols are incorporated in the termios and
1086 socket modules.
1087
1088- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1089 better tests for pickling.
1090
1091- threading: make Condition.wait() robust against KeyboardInterrupt.
1092
1093- zipfile: add support to zipfile to support opening an archive
1094 represented by an open file rather than a file name. Fix bug where
1095 the archive was not properly closed. Fixed a bug in this bugfix
1096 where flush() was called for a read-only file.
1097
1098- imputil: added an uninstall() method to the ImportManager.
1099
1100- Canvas: fixed bugs in lower() and tkraise() methods.
1101
1102- SocketServer: API change (added overridable close_request() method)
1103 so that the TCP server can explicitly close the request.
1104
1105- pstats: Eric Raymond added a simple interactive statistics browser,
1106 invoked when the module is run as a script.
1107
1108- locale: fixed a problem in format().
1109
1110- webbrowser: made it work when the BROWSER environment variable has a
1111 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1112 KDE 2. Fixed some other nits.
1113
1114- unittest: changes to allow using a different exception than
1115 AssertionError, and added a few more function aliases. Some other
1116 small changes.
1117
1118- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1119
1120- asynchat: fixed a critical bug in asynchat that slipped through the
1121 2.1b2 release. Fixed another rare bug.
1122
1123- Fix some unqualified except: clauses (always a bad code example).
1124
1125XML
1126
1127- pyexpat: new API get_version_string().
1128
1129- Fixed some minidom bugs.
1130
1131Extensions
1132
1133- Fixed a core dump in _weakref. Removed the weakref.mapping()
1134 function (it adds nothing to the API).
1135
1136- Rationalized the use of header files in the readline module, to make
1137 it compile (albeit with some warnings) with the very recent readline
1138 4.2, without breaking for earlier versions.
1139
1140- Hopefully fixed a buffering problem in linuxaudiodev.
1141
1142- Attempted a fix to make the OpenSSL support in the socket module
1143 work again with pre-0.9.5 versions of OpenSSL.
1144
1145Tests
1146
1147- Added a test case for asynchat and asyncore.
1148
1149- Removed coupling between tests where one test failing could break
1150 another.
1151
1152Tools
1153
1154- Ping added an interactive help browser to pydoc, fixed some nits
1155 in the rest of the pydoc code, and added some features to his
1156 inspect module.
1157
1158- An updated python-mode.el version 4.1 which integrates Ken
1159 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1160 much nicer in XEmacs and Emacs. When stepping through your program
1161 with pdb, in either the shell window or the *Python* window, the
1162 source file and line will be tracked by an arrow. Very cool!
1163
1164- IDLE: syntax warnings in interactive mode are changed into errors.
1165
1166- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001167 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001168
1169- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001170
Barry Warsaw11e89c72001-04-11 20:37:57 +00001171
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001172What's New in Python 2.1 beta 2?
1173================================
1174
Guido van Rossum053ae352001-03-22 14:17:21 +00001175(Unlisted are many fixed bugs, more documentation, etc.)
1176
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001177Core language, builtins, and interpreter
1178
Guido van Rossum053ae352001-03-22 14:17:21 +00001179- The nested scopes work (enabled by "from __future__ import
1180 nested_scopes") is completed; in particular, the future now extends
1181 into code executed through exec, eval() and execfile(), and into the
1182 interactive interpreter.
1183
1184- When calling a base class method (e.g. BaseClass.__init__(self)),
1185 this is now allowed even if self is not strictly spoken a class
1186 instance (e.g. when using metaclasses or the Don Beaudry hook).
1187
1188- Slice objects are now comparable but not hashable; this prevents
1189 dict[:] from being accepted but meaningless.
1190
1191- Complex division is now calculated using less braindead algorithms.
1192 This doesn't change semantics except it's more likely to give useful
1193 results in extreme cases. Complex repr() now uses full precision
1194 like float repr().
1195
1196- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1197
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001198- It is illegal to assign to the name __debug__, which is set when the
1199 interpreter starts. It is effectively a compile-time constant.
1200
1201- A warning will be issued if a global statement for a variable
1202 follows a use or assignment of that variable.
1203
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001204Standard library
1205
Guido van Rossum053ae352001-03-22 14:17:21 +00001206- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1207 inspired by JUnit), is now part of the standard library. You now
1208 have a choice of two testing frameworks: unittest requires you to
1209 write testcases as separate code, doctest gathers them from
1210 docstrings. Both approaches have their advantages and
1211 disadvantages.
1212
1213- A new module Tix was added, which wraps the Tix extension library
1214 for Tk. With that module, it is not necessary to statically link
1215 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1216 require" command. See Demo/tix/.
1217
1218- tzparse.py is now obsolete.
1219
1220- In gzip.py, the seek() and tell() methods are removed -- they were
1221 non-functional anyway, and it's better if callers can test for their
1222 existence with hasattr().
1223
1224Python/C API
1225
1226- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1227 that's already in the dictionary during a PyDict_Next() iteration.
1228 This used to fail occasionally when a dictionary resize operation
1229 could be triggered that would rehash all the keys. All other
1230 modifications to the dictionary are still off-limits during a
1231 PyDict_Next() iteration!
1232
1233- New extended APIs related to passing compiler variables around.
1234
1235- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1236 implement isinstance() and issubclass().
1237
1238- Py_BuildValue() now has a "D" conversion to create a Python complex
1239 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001240
Fred Drake4e262a92001-03-22 18:26:47 +00001241- Extensions types which support weak references must now set the
1242 field allocated for the weak reference machinery to NULL themselves;
1243 this is done to avoid the cost of checking each object for having a
1244 weakly referencable type in PyObject_INIT(), since most types are
1245 not weakly referencable.
1246
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001247- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1248 free variables and cell variables to and from the frame's f_locals.
1249
1250- Variants of several functions defined in pythonrun.h have been added
1251 to support the nested_scopes future statement. The variants all end
1252 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1253 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1254 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001255 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001256
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001257Distutils
1258
1259- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1260 into the release tree.
1261
Tim Peters0e57abf2001-05-02 07:39:38 +00001262- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001263 (an uninstaller, more customization of the installer's display)
1264
1265- from Jack Jansen: added Mac-specific code to generate a dialog for
1266 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001267 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001268 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001269
1270- added 'platforms' and 'keywords' to the set of metadata that can be
1271 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001272
1273- applied patches from Jason Tishler to make the compiler class work with
1274 Cygwin.
1275
1276
Tim Peters2fe289a2001-03-01 22:19:38 +00001277What's New in Python 2.1 beta 1?
1278================================
Tim Petersd66595f2001-02-04 03:09:53 +00001279
1280Core language, builtins, and interpreter
1281
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001282- Following an outcry from the community about the amount of code
1283 broken by the nested scopes feature introduced in 2.1a2, we decided
1284 to make this feature optional, and to wait until Python 2.2 (or at
1285 least 6 months) to make it standard. The option can be enabled on a
1286 per-module basis by adding "from __future__ import nested_scopes" at
1287 the beginning of a module (before any other statements, but after
1288 comments and an optional docstring). See PEP 236 (Back to the
1289 __future__) for a description of the __future__ statement. PEP 227
1290 (Statically Nested Scopes) has been updated to reflect this change,
1291 and to clarify the semantics in a number of endcases.
1292
1293- The nested scopes code, when enabled, has been hardened, and most
1294 bugs and memory leaks in it have been fixed.
1295
1296- Compile-time warnings are now generated for a number of conditions
1297 that will break or change in meaning when nested scopes are enabled:
1298
1299 - Using "from...import *" or "exec" without in-clause in a function
1300 scope that also defines a lambda or nested function with one or
1301 more free (non-local) variables. The presence of the import* or
1302 bare exec makes it impossible for the compiler to determine the
1303 exact set of local variables in the outer scope, which makes it
1304 impossible to determine the bindings for free variables in the
1305 inner scope. To avoid the warning about import *, change it into
1306 an import of explicitly name object, or move the import* statement
1307 to the global scope; to avoid the warning about bare exec, use
1308 exec...in... (a good idea anyway -- there's a possibility that
1309 bare exec will be deprecated in the future).
1310
1311 - Use of a global variable in a nested scope with the same name as a
1312 local variable in a surrounding scope. This will change in
1313 meaning with nested scopes: the name in the inner scope will
1314 reference the variable in the outer scope rather than the global
1315 of the same name. To avoid the warning, either rename the outer
1316 variable, or use a global statement in the inner function.
1317
Neil Schemenauera35c6882001-02-27 04:45:05 +00001318- An optional object allocator has been included. This allocator is
1319 optimized for Python objects and should be faster and use less memory
1320 than the standard system allocator. It is not enabled by default
1321 because of possible thread safety problems. The allocator is only
1322 protected by the Python interpreter lock and it is possible that some
1323 extension modules require a thread safe allocator. The object
1324 allocator can be enabled by providing the "--with-pymalloc" option to
1325 configure.
1326
Tim Petersd66595f2001-02-04 03:09:53 +00001327Standard library
1328
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001329- pyexpat now detects the expat version if expat.h defines it. A
1330 number of additional handlers are provided, which are only available
1331 since expat 1.95. In addition, the methods SetParamEntityParsing and
1332 GetInputContext of Parser objects are available with 1.95.x
1333 only. Parser objects now provide the ordered_attributes and
1334 specified_attributes attributes. A new module expat.model was added,
1335 which offers a number of additional constants if 1.95.x is used.
1336
1337- xml.dom offers the new functions registerDOMImplementation and
1338 getDOMImplementation.
1339
1340- xml.dom.minidom offers a toprettyxml method. A number of DOM
1341 conformance issues have been resolved. In particular, Element now
1342 has an hasAttributes method, and the handling of namespaces was
1343 improved.
1344
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001345- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1346 getting information about live Python code, and pydoc.py, a module
1347 for interactively converting docstrings to HTML or text.
1348 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001349 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001350 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1351 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001352
Tim Peters1eff7962001-03-01 02:31:33 +00001353- New library module difflib.py, primarily packaging the SequenceMatcher
1354 class at the heart of the popular ndiff.py file-comparison tool.
1355
1356- doctest.py (a framework for verifying Python code examples in docstrings)
1357 is now part of the std library.
1358
Tim Petersd66595f2001-02-04 03:09:53 +00001359Windows changes
1360
Guido van Rossume3955a82001-03-02 14:05:59 +00001361- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1362 small GUI that lets you browse the module docstrings using your
1363 default web browser.
1364
Tim Peters1eff7962001-03-01 02:31:33 +00001365- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1366 Platforms) is implemented. See
1367
1368 http://python.sourceforge.net/peps/pep-0235.html
1369
1370 for full details, especially the "Current Lower-Left Semantics" section.
1371 The new Windows import rules are simpler than before:
1372
1373 A. If the PYTHONCASEOK environment variable exists, same as
1374 before: silently accept the first case-insensitive match of any
1375 kind; raise ImportError if none found.
1376
1377 B. Else search sys.path for the first case-sensitive match; raise
1378 ImportError if none found.
1379
1380 The same rules have been implented on other platforms with case-
1381 insensitive but case-preserving filesystems too (including Cygwin, and
1382 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001383
Tim Peters25a9ce32001-02-19 07:06:36 +00001384- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1385 what it's supposed to do (and does do under NT and 2000) via direct
1386 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001387 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001388 all Win9x systems before.
1389
Tim Peters1eff7962001-03-01 02:31:33 +00001390- Build: Subproject _test (effectively) renamed to _testcapi.
1391
Tim Peters2fe289a2001-03-01 22:19:38 +00001392New platforms
1393
1394- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1395 Thanks to Steven Majewski!
1396
1397- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1398 Tishler!
1399
Guido van Rossum9089b272001-03-02 06:49:50 +00001400- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1401 Schwertberger! See RISCOS/README for more information -- it seems
1402 that because of the bizarre filename conventions on RISCOS, no port
1403 to that platform is easy. Note that the new variable os.endsep is
1404 silently supported in order to make life easier on this platform,
1405 but we don't advertise it because it's not worth for most folks to
1406 care about RISCOS portability.
1407
Tim Peters25a9ce32001-02-19 07:06:36 +00001408
Tim Petersd7b5e882001-01-25 03:36:26 +00001409What's New in Python 2.1 alpha 2?
1410=================================
Tim Peters40ead762001-01-27 05:35:26 +00001411
Tim Petersd7b5e882001-01-25 03:36:26 +00001412Core language, builtins, and interpreter
1413
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001414- Scopes nest. If a name is used in a function or class, but is not
1415 local, the definition in the nearest enclosing function scope will
1416 be used. One consequence of this change is that lambda statements
1417 could reference variables in the namespaces where the lambda is
1418 defined. In some unusual cases, this change will break code.
1419
1420 In all previous version of Python, names were resolved in exactly
1421 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001422 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001423 function A is defined within a function B, the names bound in B are
1424 not visible in A. The new rules make names bound in B visible in A,
1425 unless A contains a name binding that hides the binding in B.
1426
1427 Section 4.1 of the reference manual describes the new scoping rules
1428 in detail. The test script in Lib/test/test_scope.py demonstrates
1429 some of the effects of the change.
1430
1431 The new rules will cause existing code to break if it defines nested
1432 functions where an outer function has local variables with the same
1433 name as globals or builtins used by the inner function. Example:
1434
1435 def munge(str):
1436 def helper(x):
1437 return str(x)
1438 if type(str) != type(''):
1439 str = helper(str)
1440 return str.strip()
1441
1442 Under the old rules, the name str in helper() is bound to the
1443 builtin function str(). Under the new rules, it will be bound to
1444 the argument named str and an error will occur when helper() is
1445 called.
1446
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001447- The compiler will report a SyntaxError if "from ... import *" occurs
1448 in a function or class scope. The language reference has documented
1449 that this case is illegal, but the compiler never checked for it.
1450 The recent introduction of nested scope makes the meaning of this
1451 form of name binding ambiguous. In a future release, the compiler
1452 may allow this form when there is no possibility of ambiguity.
1453
Tim Peters40ead762001-01-27 05:35:26 +00001454- repr(string) is easier to read, now using hex escapes instead of octal,
1455 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1456
1457 >>> "\texample \r\n" + chr(0) + chr(255)
1458 '\texample \r\n\x00\xff' # in 2.1
1459 '\011example \015\012\000\377' # in 2.0
1460
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001461- Functions are now compared and hashed by identity, not by value, since
1462 the func_code attribute is writable.
1463
Fred Drakefb9d7122001-02-01 20:00:40 +00001464- Weak references (PEP 205) have been added. This involves a few
1465 changes in the core, an extension module (_weakref), and a Python
1466 module (weakref). The weakref module is the public interface. It
1467 includes support for "explicit" weak references, proxy objects, and
1468 mappings with weakly held values.
1469
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001470- A 'continue' statement can now appear in a try block within the body
1471 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001472 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001473
Tim Petersd7b5e882001-01-25 03:36:26 +00001474Standard library
1475
Barry Warsaw30dbd142001-01-31 22:14:01 +00001476- mailbox.py now has a new class, PortableUnixMailbox which is
1477 identical to UnixMailbox but uses a more portable scheme for
1478 determining From_ separators. Also, the constructors for all the
1479 classes in this module have a new optional `factory' argument, which
1480 is a callable used when new message classes must be instantiated by
1481 the next() method.
1482
Tim Petersd7b5e882001-01-25 03:36:26 +00001483- random.py is now self-contained, and offers all the functionality of
1484 the now-deprecated whrandom.py. See the docs for details. random.py
1485 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001486 and restoring the internal state of the generator; and jumpahead(n),
1487 for quickly forcing the internal state to be the same as if n calls to
1488 random() had been made. The latter is particularly useful for multi-
1489 threaded programs, creating one instance of the random.Random() class for
1490 each thread, then using .jumpahead() to force each instance to use a
1491 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001492
Tim Peters0de88fc2001-02-01 04:59:18 +00001493- random.py's seed() function is new. For bit-for-bit compatibility with
1494 prior releases, use the whseed function instead. The new seed function
1495 addresses two problems: (1) The old function couldn't produce more than
1496 about 2**24 distinct internal states; the new one about 2**45 (the best
1497 that can be done in the Wichmann-Hill generator). (2) The old function
1498 sometimes produced identical internal states when passed distinct
1499 integers, and there was no simple way to predict when that would happen;
1500 the new one guarantees to produce distinct internal states for all
1501 arguments in [0, 27814431486576L).
1502
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001503- The socket module now supports raw packets on Linux. The socket
1504 family is AF_PACKET.
1505
Tim Peters9ea17ac2001-02-02 05:57:15 +00001506- test_capi.py is a start at running tests of the Python C API. The tests
1507 are implemented by the new Modules/_testmodule.c.
1508
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001509- A new extension module, _symtable, provides provisional access to the
1510 internal symbol table used by the Python compiler. A higher-level
1511 interface will be added on top of _symtable in a future release.
1512
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001513- Removed the obsolete soundex module.
1514
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001515- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1516 the isSameNode method; NamedNodeMap the get method.
1517
1518- xml.sax.expatreader supports the lexical handler property; it
1519 generates comment, startCDATA, and endCDATA events.
1520
Tim Petersee826f82001-01-31 19:39:44 +00001521Windows changes
1522
1523- Build procedure: the zlib project is built in a different way that
1524 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001525 the zlib binary used. See PCbuild\readme.txt for details. Your old
1526 zlib-related directories can be deleted; you'll need to download fresh
1527 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001528
Tim Peters9ea17ac2001-02-02 05:57:15 +00001529- Build: New subproject _test for the benefit of test_capi.py (see above).
1530
Tim Petersb16c56f2001-02-02 21:24:51 +00001531- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1532 interface to some Python compiler internals).
1533
1534- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001535 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001536
Tim Petersa3a3a032000-11-30 05:22:44 +00001537What's New in Python 2.1 alpha 1?
1538=================================
1539
1540Core language, builtins, and interpreter
1541
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001542- There is a new Unicode companion to the PyObject_Str() API
1543 called PyObject_Unicode(). It behaves in the same way as the
1544 former, but assures that the returned value is an Unicode object
1545 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001546
Guido van Rossumf98eda02001-01-17 15:54:45 +00001547- The comparison operators support "rich comparison overloading" (PEP
1548 207). C extension types can provide a rich comparison function in
1549 the new tp_richcompare slot in the type object. The cmp() function
1550 and the C function PyObject_Compare() first try the new rich
1551 comparison operators before trying the old 3-way comparison. There
1552 is also a new C API PyObject_RichCompare() (which also falls back on
1553 the old 3-way comparison, but does not constrain the outcome of the
1554 rich comparison to a Boolean result).
1555
1556 The rich comparison function takes two objects (at least one of
1557 which is guaranteed to have the type that provided the function) and
1558 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1559 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1560 object, which may be NotImplemented (in which case the tp_compare
1561 slot function is used as a fallback, if defined).
1562
1563 Classes can overload individual comparison operators by defining one
1564 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001565 __ge__. There are no explicit "reflected argument" versions of
1566 these; instead, __lt__ and __gt__ are each other's reflection,
1567 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1568 reflection (similar at the C level). No other implications are
1569 made; in particular, Python does not assume that == is the Boolean
1570 inverse of !=, or that < is the Boolean inverse of >=. This makes
1571 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001572
1573 Classes or types that want to implement (in)equality tests but not
1574 the ordering operators (i.e. unordered types) should implement ==
1575 and !=, and raise an error for the ordering operators.
1576
Guido van Rossuma88479f2001-01-18 14:28:08 +00001577 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001578 Boolean; e.g. a matrix type might want to return a matrix of bits
1579 for A < B, giving elementwise comparisons. Such types should ensure
1580 that any interpretation of their value in a Boolean context raises
1581 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1582 at the C level) to always raise an exception.
1583
Guido van Rossuma88479f2001-01-18 14:28:08 +00001584- Complex numbers use rich comparisons to define == and != but raise
1585 an exception for <, <=, > and >=. Unfortunately, this also means
1586 that cmp() of two complex numbers raises an exception when the two
1587 numbers differ. Since it is not mathematically meaningful to compare
1588 complex numbers except for equality, I hope that this doesn't break
1589 too much code.
1590
Tim Peters3389f192001-02-18 08:48:49 +00001591- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001592 not defined by the language, other than that it's arbitrary but
1593 consistent (see the Reference Manual). An implementation detail changed
1594 in 2.1a1 such that None now compares less than any other object. Code
1595 relying on this new behavior (like code that relied on the previous
1596 behavior) does so at its own risk.
1597
Barry Warsaw573b5412001-01-15 20:43:18 +00001598- Functions and methods now support getting and setting arbitrarily
1599 named attributes (PEP 232). Functions have a new __dict__
1600 (a.k.a. func_dict) which hold the function attributes. Methods get
1601 and set attributes on their underlying im_func. It is a TypeError
1602 to set an attribute on a bound method.
1603
Guido van Rossum051e3352001-01-15 19:11:10 +00001604- The xrange() object implementation has been improved so that
1605 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1606 limitation that in this case len(xrange(sys.maxint)) can't be
1607 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1608 work fine as long as the index i doesn't actually reach 2**31.
1609 (Python uses regular ints for sequence and string indices; fixing
1610 that is much more work.)
1611
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001612- Two changes to from...import:
1613
Guido van Rossumba381232001-02-03 15:06:40 +00001614 1) "from M import X" now works even if (after loading module M)
1615 sys.modules['M'] is not a real module; it's basically a getattr()
1616 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001617
1618 2) "from M import *" now looks for M.__all__ to decide which names to
1619 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1620 filters out names starting with '_' as before. Whether or not
1621 __all__ exists, there's no restriction on the type of M.
1622
Guido van Rossumf61f1662001-01-10 20:13:55 +00001623- File objects have a new method, xreadlines(). This is the fastest
1624 way to iterate over all lines in a file:
1625
1626 for line in file.xreadlines():
1627 ...do something to line...
1628
1629 See the xreadlines module (mentioned below) for how to do this for
1630 other file-like objects.
1631
1632- Even if you don't use file.xreadlines(), you may expect a speedup on
1633 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001634 quite a bit in platform-specific ways: on systems (like Linux) that
1635 support flockfile(), getc_unlocked(), and funlockfile(), those are
1636 used by default. On systems (like Windows) without getc_unlocked(),
1637 a complicated (but still thread-safe) method using fgets() is used by
1638 default.
1639
Tim Petersd52269b2001-01-25 06:23:18 +00001640 You can force use of the fgets() method by #define'ing
1641 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001642 getc_unlocked()).
1643
Tim Petersd52269b2001-01-25 06:23:18 +00001644 You can force fgets() not to be used by #define'ing
1645 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001646 test_bufio.py fails -- and let us know if it does!).
1647
1648- In addition, the fileinput module, while still slower than the other
1649 methods on most platforms, has been sped up too, by using
1650 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001651
1652- Support for run-time warnings has been added, including a new
1653 command line option (-W) to specify the disposition of warnings.
1654 See the description of the warnings module below.
1655
1656- Extensive changes have been made to the coercion code. This mostly
1657 affects extension modules (which can now implement mixed-type
1658 numerical operators without having to use coercion), but
1659 occasionally, in boundary cases the coercion semantics have changed
1660 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001661 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001662 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001663 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001664
Guido van Rossumf98eda02001-01-17 15:54:45 +00001665- In connection with the coercion changes, a new built-in singleton
1666 object, NotImplemented is defined. This can be returned for
1667 operations that wish to indicate they are not implemented for a
1668 particular combination of arguments. From C, this is
1669 Py_NotImplemented.
1670
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001671- The interpreter accepts now bytecode files on the command line even
1672 if they do not have a .pyc or .pyo extension. On Linux, after executing
1673
Martin v. Löwise214baa2001-02-04 22:37:56 +00001674import imp,sys,string
1675magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1676reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1677open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001678
1679 any byte code file can be used as an executable (i.e. as an argument
1680 to execve(2)).
1681
Tim Peters9940b802000-12-01 07:59:35 +00001682- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001683 character. In 1.6 and earlier, they never produced a sign,
1684 and raised an error if the value of the long was too large
1685 to fit in a Python int. In 2.0, they produced a sign if and
1686 only if too large to fit in an int. This was inconsistent
1687 across platforms (because the size of an int varies across
1688 platforms), and inconsistent with hex() and oct(). Example:
1689
1690 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001691 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001692 'ffffffbe' # in 2.0 and before, on 32-bit machines
1693 >>> hex(-0x42L)
1694 '-0x42L' # in all versions of Python
1695
Tim Peters9940b802000-12-01 07:59:35 +00001696 The behavior of %d formats for negative Python longs remains
1697 the same as in 2.0 (although in 1.6 and before, they raised
1698 an error if the long didn't fit in a Python int).
1699
1700 %u formats don't make sense for Python longs, but are allowed
1701 and treated the same as %d in 2.1. In 2.0, a negative long
1702 formatted via %u produced a sign if and only if too large to
1703 fit in an int. In 1.6 and earlier, a negative long formatted
1704 via %u raised an error if it was too big to fit in an int.
1705
Guido van Rossum3661d392000-12-12 22:10:31 +00001706- Dictionary objects have an odd new method, popitem(). This removes
1707 an arbitrary item from the dictionary and returns it (in the form of
1708 a (key, value) pair). This can be useful for algorithms that use a
1709 dictionary as a bag of "to do" items and repeatedly need to pick one
1710 item. Such algorithms normally end up running in quadratic time;
1711 using popitem() they can usually be made to run in linear time.
1712
Tim Peters36cdad12000-12-29 02:06:45 +00001713Standard library
1714
Thomas Woutersfe385252001-01-19 23:16:56 +00001715- In the time module, the time argument to the functions strftime,
1716 localtime, gmtime, asctime and ctime is now optional, defaulting to
1717 the current time (in the local timezone).
1718
Guido van Rossumda91f222001-01-15 16:36:08 +00001719- The ftplib module now defaults to passive mode, which is deemed a
1720 more useful default given that clients are often inside firewalls
1721 these days. Note that this could break if ftplib is used to connect
1722 to a *server* that is inside a firewall, from outside; this is
1723 expected to be a very rare situation. To fix that, you can call
1724 ftp.set_pasv(0).
1725
Martin v. Löwis10a27872001-01-13 09:54:41 +00001726- The module site now treats .pth files not only for path configuration,
1727 but also supports extensions to the initialization code: Lines starting
1728 with import are executed.
1729
Guido van Rossumf61f1662001-01-10 20:13:55 +00001730- There's a new module, warnings, which implements a mechanism for
1731 issuing and filtering warnings. There are some new built-in
1732 exceptions that serve as warning categories, and a new command line
1733 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1734 turns warnings into errors). warnings.warn(message[, category])
1735 issues a warning message; this can also be called from C as
1736 PyErr_Warn(category, message).
1737
1738- A new module xreadlines was added. This exports a single factory
1739 function, xreadlines(). The intention is that this code is the
1740 absolutely fastest way to iterate over all lines in an open
1741 file(-like) object:
1742
1743 import xreadlines
1744 for line in xreadlines.xreadlines(file):
1745 ...do something to line...
1746
1747 This is equivalent to the previous the speed record holder using
1748 file.readlines(sizehint). Note that if file is a real file object
1749 (as opposed to a file-like object), this is equivalent:
1750
1751 for line in file.xreadlines():
1752 ...do something to line...
1753
Tim Peters36cdad12000-12-29 02:06:45 +00001754- The bisect module has new functions bisect_left, insort_left,
1755 bisect_right and insort_right. The old names bisect and insort
1756 are now aliases for bisect_right and insort_right. XXX_right
1757 and XXX_left methods differ in what happens when the new element
1758 compares equal to one or more elements already in the list: the
1759 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001760 right. Code that doesn't care where equal elements end up should
1761 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001762
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001763- The new curses.panel module wraps the panel library that forms part
1764 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1765
Guido van Rossumf61f1662001-01-10 20:13:55 +00001766- The SocketServer module now sets the allow_reuse_address flag by
1767 default in the TCPServer class.
1768
1769- A new function, sys._getframe(), returns the stack frame pointer of
1770 the caller. This is intended only as a building block for
1771 higher-level mechanisms such as string interpolation.
1772
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001773- The pyexpat module supports a number of new handlers, which are
1774 available only in expat 1.2. If invocation of a callback fails, it
1775 will report an additional frame in the traceback. Parser objects
1776 participate now in garbage collection. If expat reports an unknown
1777 encoding, pyexpat will try to use a Python codec; that works only
1778 for single-byte charsets. The parser type objects is exposed as
1779 XMLParserObject.
1780
1781- xml.dom now offers standard definitions for symbolic node type and
1782 exception code constants, and a hierarchy of DOM exceptions. minidom
1783 was adjusted to use them.
1784
1785- The conformance of xml.dom.minidom to the DOM specification was
1786 improved. It detects a number of additional error cases; the
1787 previous/next relationship works even when the tree is modified;
1788 Node supports the normalize() method; NamedNodeMap, DocumentType and
1789 DOMImplementation classes were added; Element supports the
1790 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1791 method.
1792
Guido van Rossumf61f1662001-01-10 20:13:55 +00001793Build issues
1794
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001795- For Unix (and Unix-compatible) builds, configuration and building of
1796 extension modules is now greatly automated. Rather than having to
1797 edit the Modules/Setup file to indicate which modules should be
1798 built and where their include files and libraries are, a
1799 distutils-based setup.py script now takes care of building most
1800 extension modules. All extension modules built this way are built
1801 as shared libraries. Only a few modules that must be linked
1802 statically are still listed in the Setup file; you won't need to
1803 edit their configuration.
1804
1805- Python should now build out of the box on Cygwin. If it doesn't,
1806 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001807
1808- Python now always uses its own (renamed) implementation of getopt()
1809 -- there's too much variation among C library getopt()
1810 implementations.
1811
1812- C++ compilers are better supported; the CXX macro is always set to a
1813 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001814
Tim Petersd92dfe02000-12-12 01:18:41 +00001815Windows changes
1816
1817- select module: By default under Windows, a select() call
1818 can specify no more than 64 sockets. Python now boosts
1819 this Microsoft default to 512. If you need even more than
1820 that, see the MS docs (you'll need to #define FD_SETSIZE
1821 and recompile Python from source).
1822
Guido van Rossumf61f1662001-01-10 20:13:55 +00001823- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1824 subdirectory is no more!
1825
Tim Petersa3a3a032000-11-30 05:22:44 +00001826
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001827What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001828=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001829
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001830Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001831changes are in the file HISTORY. If you are making the jump directly
1832from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1833HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001834
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001835Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1836the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1837http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001838
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001839--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001840
1841======================================================================
1842
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001843What's new in 2.0 (since release candidate 1)?
1844==============================================
1845
1846Standard library
1847
1848- The copy_reg module was modified to clarify its intended use: to
1849 register pickle support for extension types, not for classes.
1850 pickle() will raise a TypeError if it is passed a class.
1851
1852- Fixed a bug in gettext's "normalize and expand" code that prevented
1853 it from finding an existing .mo file.
1854
1855- Restored support for HTTP/0.9 servers in httplib.
1856
Tim Peters989b7b92000-10-16 20:24:53 +00001857- The math module was changed to stop raising OverflowError in case of
1858 underflow, and return 0 instead in underflow cases. Whether Python
1859 used to raise OverflowError in case of underflow was platform-
1860 dependent (it did when the platform math library set errno to ERANGE
1861 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001862
1863- Fixed a bug in StringIO that occurred when the file position was not
1864 at the end of the file and write() was called with enough data to
1865 extend past the end of the file.
1866
1867- Fixed a bug that caused Tkinter error messages to get lost on
1868 Windows. The bug was fixed by replacing direct use of
1869 interp->result with Tcl_GetStringResult(interp).
1870
1871- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1872 redirect response.
1873
1874- Several changes were made to distutils: Some debugging code was
1875 removed from util. Fixed the installer used when an external zip
1876 program (like WinZip) is not found; the source code for this
1877 installer is in Misc/distutils. check_lib() was modified to behave
1878 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1879 test for whether installed modules are on sys.path was changed to
1880 use both normcase() and normpath().
1881
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001882- Several minor bugs were fixed in the xml package (the minidom,
1883 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001884
1885- The regression test driver (regrtest.py) behavior when invoked with
1886 -l changed: It now reports a count of objects that are recognized as
1887 garbage but not freed by the garbage collector.
1888
Tim Peters989b7b92000-10-16 20:24:53 +00001889- The regression test for the math module was changed to test
1890 exceptional behavior when the test is run in verbose mode. Python
1891 cannot yet guarantee consistent exception behavior across platforms,
1892 so the exception part of test_math is run only in verbose mode, and
1893 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001894
1895Internals
1896
1897- PyOS_CheckStack() has been disabled on Win64, where it caused
1898 test_sre to fail.
1899
1900Build issues
1901
1902- Changed compiler flags, so that gcc is always invoked with -Wall and
1903 -Wstrict-prototypes. Users compiling Python with GCC should see
1904 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001905 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001906 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001907
Tim Petersa3a3a032000-11-30 05:22:44 +00001908- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001909
1910Tools and other miscellany
1911
1912- The compiler in Tools/compiler was updated to support the new
1913 language features introduced in 2.0: extended print statement, list
1914 comprehensions, and augmented assignments. The new compiler should
1915 also be backwards compatible with Python 1.5.2; the compiler will
1916 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001917 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001918
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001919What's new in 2.0 release candidate 1 (since beta 2)?
1920=====================================================
1921
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001922What is release candidate 1?
1923
1924We believe that release candidate 1 will fix all known bugs that we
1925intend to fix for the 2.0 final release. This release should be a bit
1926more stable than the previous betas. We would like to see even more
1927widespread testing before the final release, so we are producing this
1928release candidate. The final release will be exactly the same unless
1929any show-stopping (or brown bag) bugs are found by testers of the
1930release candidate.
1931
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001932All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001933to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001934
1935Core language, builtins, and interpreter
1936
1937- A bug that caused crashes when __coerce__ was used with augmented
1938 assignment, e.g. +=, was fixed.
1939
1940- Raise ZeroDivisionError when raising zero to a negative number,
1941 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1942 power operator and the result of math.pow(0.0, -2.0) will vary by
1943 platform. On Linux, it raises a ValueError.
1944
1945- A bug in Unicode string interpolation was fixed that occasionally
1946 caused errors with formats including "%%". For example, the
1947 following expression "%% %s" % u"abc" no longer raises a TypeError.
1948
1949- Compilation of deeply nested expressions raises MemoryError instead
1950 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1951
1952- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1953 rendering them useless. They are now written in binary mode again.
1954
1955Standard library
1956
1957- Keyword arguments are now accepted for most pattern and match object
1958 methods in SRE, the standard regular expression engine.
1959
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001960- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001961 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001962
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001963- Several bugs in the Unicode handling and error handling in _tkinter
1964 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001965
1966- Fix memory management errors in Merge() and Tkapp_Call() routines.
1967
1968- Several changes were made to cStringIO to make it compatible with
1969 the file-like object interface and with StringIO. If operations are
1970 performed on a closed object, an exception is raised. The truncate
1971 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001972 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001973
1974- There were many changes made to the linuxaudiodev module and its
1975 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001976 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001977
1978 Note that this module is named poorly, because it should work
1979 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001980 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001981
1982 The module now raises exceptions when errors occur instead of
1983 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1984 audio) and defines a getptr() method that calls the
1985 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1986
1987- The library_version attribute, introduced in an earlier beta, was
1988 removed because it can not be supported with early versions of the C
1989 readline library, which provides no way to determine the version at
1990 compile-time.
1991
1992- The binascii module is now enabled on Win64.
1993
Tim Peters46446d62000-10-09 21:19:31 +00001994- tokenize.py no longer suffers "recursion depth" errors when parsing
1995 programs with very long string literals.
1996
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001997Internals
1998
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001999- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002000 which is called when the interpreter starts up to determine where
2001 the standard library is installed. These vulnerabilities affect all
2002 previous versions of Python and can be exploited by setting very
2003 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2004 setuid Python script, although use of the wrapper in
2005 Misc/setuid-prog.c will eliminate the vulnerability.
2006
2007- Fixed garbage collection bugs in instance creation that were
2008 triggered when errors occurred during initialization. The solution,
2009 applied in cPickle and in PyInstance_New(), is to call
2010 PyObject_GC_Init() after the initialization of the object's
2011 container attributes is complete.
2012
2013- pyexpat adds definitions of PyModule_AddStringConstant and
2014 PyModule_AddObject if the Python version is less than 2.0, which
2015 provides compatibility with PyXML on Python 1.5.2.
2016
2017- If the platform has a bogus definition for LONG_BIT (the number of
2018 bits in a long), an error will be reported at compile time.
2019
2020- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2021 collection crashes and possibly other, unreported crashes.
2022
2023- Fixed a memory leak in _PyUnicode_Fini().
2024
2025Build issues
2026
2027- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002028 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002029 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002030
2031- The mmap.PAGESIZE constant is now initialized using sysconf when
2032 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2033
2034- The md5 file should now compile on all platforms.
2035
2036- The select module now compiles on platforms that do not define
2037 POLLRDNORM and related constants.
2038
2039- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002040 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002041
Jeremy Hylton10921202000-10-09 18:34:12 +00002042- BeOS: A number of changes were made to the build and installation
2043 process. ar-fake now operates on a directory of object files.
2044 dl_export.h is gone, and its macros now appear on the mwcc command
2045 line during build on PPC BeOS.
2046
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002047- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002048 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002049
2050- Cygwin: Support for shared libraries, Tkinter, and sockets.
2051
2052- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2053
2054Tools and other miscellany
2055
2056- Removed debugging prints from main used with freeze.
2057
Tim Peters46446d62000-10-09 21:19:31 +00002058- IDLE auto-indent no longer crashes when it encounters Unicode
2059 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002060
2061What's new in 2.0 beta 2 (since beta 1)?
2062========================================
2063
2064Core language, builtins, and interpreter
2065
Tim Peters482c0212000-09-26 06:33:09 +00002066- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002067 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002068
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002069- Add -h and -V command line options to print the usage message and
2070 Python version number and exit immediately.
2071
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002072- eval() and exec accept Unicode objects as code parameters.
2073
2074- getattr() and setattr() now also accept Unicode objects for the
2075 attribute name, which are converted to strings using the default
2076 encoding before lookup.
2077
2078- Multiplication on string and Unicode now does proper bounds
2079 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2080 string is too long."
2081
2082- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002083 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002084
Jeremy Hylton1b618592000-09-26 05:32:36 +00002085
2086Standard library and extensions
2087
Guido van Rossum5b08f132001-04-16 02:05:23 +00002088- socket module: the OpenSSL code now adds support for RAND_status()
2089 and EGD (Entropy Gathering Device).
2090
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002091- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002092 argument checking; it still takes no arguments.
2093
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002094- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002095
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002096- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002097
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002098- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002099
2100- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002101 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002102
2103- copy: Copy Unicode objects atomically.
2104
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002105- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002106
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002107- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002108
Fred Drake67233bc2000-09-26 16:40:27 +00002109- dbm: Add get() and setdefault() methods to dbm object. Add constant
2110 `library' to module that names the library used. Added doc strings
2111 and method names to error messages. Uses configure to determine
2112 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2113 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002114
2115- distutils: Update to version 0.9.3.
2116
2117- dl: Add several dl.RTLD_ constants.
2118
2119- fpectl: Now supported on FreeBSD.
2120
2121- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2122 found by the collector will be saved in gc.garbage. This is useful
2123 for debugging a program that creates reference cycles.
2124
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002125- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002126 of HTTP class. Do not close socket on zero-length response. Do not
2127 crash when server sends invalid content-length header.
2128
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002129- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002130
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002131- marshal: When reading a short, sign-extend on platforms where shorts
2132 are bigger than 16 bits. When reading a long, repair the unportable
2133 sign extension that was being done for 64-bit machines. (It assumed
2134 that signed right shift sign-extends.)
2135
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002136- operator: Add contains(), invert(), __invert__() as aliases for
2137 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002138
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002139- os: Add support for popen2() and popen3() on all platforms where
2140 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002141
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002142- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002143 clicking on a file in Explorer (or passing the file name to the
2144 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002145
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002146- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002147 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002148
2149- pickle: Now raises ValueError when an invalid pickle that contains
2150 a non-string repr where a string repr was expected. This behavior
2151 matches cPickle.
2152
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002153- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002154
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002155- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002156
2157- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002158 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002159 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002160
2161- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002162 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002163
2164- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002165 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002166 few cycles during startup since the first call to
2167 setdefaultencoding() will initialize the codec registry and the
2168 encodings package.
2169
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002170- socket: Support for size hint in readlines() method of object returned
2171 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002172
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002173- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002174 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002175 is followed by whitespace.
2176
Tim Petersa3a3a032000-11-30 05:22:44 +00002177- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002178
2179- struct: Check ranges for bytes and shorts.
2180
2181- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002182 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002183
2184- Tkinter: Image objects are now guaranteed to have unique ids. Set
2185 event.delta to zero if Tk version doesn't support mousewheel.
2186 Removed some debugging prints.
2187
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002188- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002189
Fred Drake67233bc2000-09-26 16:40:27 +00002190- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002191 which works around a bug in Norton AntiVirus 2000 that leads directly
2192 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002193
2194- xml: New version detection code allows PyXML to override standard
2195 XML package if PyXML version is greater than 0.6.1.
2196
Fred Drake64bb3802000-09-26 16:21:35 +00002197- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2198 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2199 tree only for nodes which are sufficiently interesting to a specific
2200 application. Does not provide the HTML-specific extensions. Still
2201 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002202
Fred Drake64bb3802000-09-26 16:21:35 +00002203- xml.sax: SAX 2 support for Python, including all the handler
2204 interfaces needed to process XML 1.0 compliant XML. Some
2205 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002206
Fred Drake64bb3802000-09-26 16:21:35 +00002207- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2208 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002209
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002210
Jeremy Hylton1b618592000-09-26 05:32:36 +00002211C API
2212
2213- Add three new convenience functions for module initialization --
2214 PyModule_AddObject(), PyModule_AddIntConstant(), and
2215 PyModule_AddStringConstant().
2216
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002217- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002218 removed and add #error to Python.h if NULL isn't defined after
2219 #include of stdio.h.
2220
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002221- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002222 backwards compatibility (at the source level) with old extensions.
2223
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002224- A wrapper API was added for signal() and sigaction(). Instead of
2225 either function, always use PyOS_getsig() to get a signal handler
2226 and PyOS_setsig() to set one. A new convenience typedef
2227 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002228
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002229- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002230 internal data buffer and size of a string object -- or the default
2231 encoded version of a Unicode object.
2232
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002233- PyString_Size() and PyString_AsString() accept Unicode objects.
2234
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002235- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002236 exists). INT_MAX and LONG_MAX will always be defined, even if
2237 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002238
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002239- PyFloat_FromString takes a second argument, pend, that was
2240 effectively useless. It is now officially useless but preserved for
2241 backwards compatibility. If the pend argument is not NULL, *pend is
2242 set to NULL.
2243
2244- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2245 for the attribute name. See note on getattr() above.
2246
2247- A few bug fixes to argument processing for Unicode.
2248 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2249 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2250 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002251 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002252
2253- Py_BuildValue accepts B format (for bgen-generated code).
2254
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002255
Jeremy Hylton1b618592000-09-26 05:32:36 +00002256Internals
2257
2258- On Unix, fix code for finding Python installation directory so that
2259 it works when argv[0] is a relative path.
2260
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002261- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002262 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002263 rather than by generating a copy of the object.
2264
Tim Peters482c0212000-09-26 06:33:09 +00002265- Several of the internal Unicode tables are much smaller now, and
2266 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002267
Jeremy Hylton97693b02000-09-26 17:42:51 +00002268- In the garbage collector: Fixed bug in collection of tuples. Fixed
2269 bug that caused some instances to be removed from the container set
2270 while they were still live. Fixed parsing in gc.set_debug() for
2271 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002272
2273- Fixed refcount problem in instance deallocation that only occurred
2274 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2275
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002276- On Windows, getpythonregpath is now protected against null data in
2277 registry key.
2278
2279- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002280 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002281
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002282
Jeremy Hylton1b618592000-09-26 05:32:36 +00002283Build and platform-specific issues
2284
2285- Better support of GNU Pth via --with-pth configure option.
2286
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002287- Python/C API now properly exposed to dynamically-loaded extension
2288 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002289
2290- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2291 Don't define MS_SYNC to be zero when it is undefined. Added missing
2292 prototypes in posixmodule.c.
2293
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002294- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002295 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002296
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002297- Fix largefile support on older NetBSD systems and OpenBSD by adding
2298 define for TELL64.
2299
2300
2301Tools and other miscellany
2302
2303- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2304
2305- freeze: The modulefinder now works with 2.0 opcodes.
2306
Tim Petersa3a3a032000-11-30 05:22:44 +00002307- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002308 Move hackery of sys.argv until after the Tk instance has been
2309 created, which allows the application-specific Tkinter
2310 initialization to be executed if present; also pass an explicit
2311 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002312
Jeremy Hylton1b618592000-09-26 05:32:36 +00002313
2314What's new in 2.0 beta 1?
2315=========================
2316
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002317Source Incompatibilities
2318------------------------
2319
2320None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2321such as single-argument append(), connect() and bind(), and changes to
2322str(long) and repr(float).
2323
2324
2325Binary Incompatibilities
2326------------------------
2327
2328- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2329with Python 2.0; these extensions will have to be rebuilt for Python
23302.0.
2331
2332- On Windows, attempting to import a third party extension built for
2333Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2334can do about this. Check your PYTHONPATH environment variable!
2335
2336- Python bytecode files (*.pyc and *.pyo) are not compatible between
2337releases.
2338
2339
2340Overview of Changes Since 1.6
2341-----------------------------
2342
2343There are many new modules (including brand new XML support through
2344the xml package, and i18n support through the gettext module); a list
2345of all new modules is included below. Lots of bugs have been fixed.
2346
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002347The process for making major new changes to the language has changed
2348since Python 1.6. Enhancements must now be documented by a Python
2349Enhancement Proposal (PEP) before they can be accepted.
2350
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002351There are several important syntax enhancements, described in more
2352detail below:
2353
2354 - Augmented assignment, e.g. x += 1
2355
2356 - List comprehensions, e.g. [x**2 for x in range(10)]
2357
2358 - Extended import statement, e.g. import Module as Name
2359
2360 - Extended print statement, e.g. print >> file, "Hello"
2361
2362Other important changes:
2363
2364 - Optional collection of cyclical garbage
2365
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002366Python Enhancement Proposal (PEP)
2367---------------------------------
2368
2369PEP stands for Python Enhancement Proposal. A PEP is a design
2370document providing information to the Python community, or describing
2371a new feature for Python. The PEP should provide a concise technical
2372specification of the feature and a rationale for the feature.
2373
2374We intend PEPs to be the primary mechanisms for proposing new
2375features, for collecting community input on an issue, and for
2376documenting the design decisions that have gone into Python. The PEP
2377author is responsible for building consensus within the community and
2378documenting dissenting opinions.
2379
2380The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002381
2382Augmented Assignment
2383--------------------
2384
2385This must have been the most-requested feature of the past years!
2386Eleven new assignment operators were added:
2387
Guido van Rossume905e952000-09-05 12:42:46 +00002388 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002389
2390For example,
2391
2392 A += B
2393
2394is similar to
2395
2396 A = A + B
2397
2398except that A is evaluated only once (relevant when A is something
2399like dict[index].attr).
2400
2401However, if A is a mutable object, A may be modified in place. Thus,
2402if A is a number or a string, A += B has the same effect as A = A+B
2403(except A is only evaluated once); but if a is a list, A += B has the
2404same effect as A.extend(B)!
2405
2406Classes and built-in object types can override the new operators in
2407order to implement the in-place behavior; the not-in-place behavior is
2408used automatically as a fallback when an object doesn't implement the
2409in-place behavior. For classes, the method name is derived from the
2410method name for the corresponding not-in-place operator by inserting
2411an 'i' in front of the name, e.g. __iadd__ implements in-place
2412__add__.
2413
2414Augmented assignment was implemented by Thomas Wouters.
2415
2416
2417List Comprehensions
2418-------------------
2419
2420This is a flexible new notation for lists whose elements are computed
2421from another list (or lists). The simplest form is:
2422
2423 [<expression> for <variable> in <sequence>]
2424
Guido van Rossum56db0952000-09-06 23:34:25 +00002425For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002426This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002427
2428You can also add a condition:
2429
2430 [<expression> for <variable> in <sequence> if <condition>]
2431
2432For example, [w for w in words if w == w.lower()] would yield the list
2433of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002434than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002435
2436You can also have nested for loops and more than one 'if' clause. For
2437example, here's a function that flattens a sequence of sequences::
2438
2439 def flatten(seq):
2440 return [x for subseq in seq for x in subseq]
2441
2442 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2443
2444This prints
2445
2446 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2447
2448List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002449Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002450
2451
2452Extended Import Statement
2453-------------------------
2454
2455Many people have asked for a way to import a module under a different
2456name. This can be accomplished like this:
2457
2458 import foo
2459 bar = foo
2460 del foo
2461
2462but this common idiom gets old quickly. A simple extension of the
2463import statement now allows this to be written as follows:
2464
2465 import foo as bar
2466
2467There's also a variant for 'from ... import':
2468
2469 from foo import bar as spam
2470
2471This also works with packages; e.g. you can write this:
2472
2473 import test.regrtest as regrtest
2474
2475Note that 'as' is not a new keyword -- it is recognized only in this
2476context (this is only possible because the syntax for the import
2477statement doesn't involve expressions).
2478
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002479Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002480
2481
2482Extended Print Statement
2483------------------------
2484
2485Easily the most controversial new feature, this extension to the print
2486statement adds an option to make the output go to a different file
2487than the default sys.stdout.
2488
2489For example, to write an error message to sys.stderr, you can now
2490write:
2491
2492 print >> sys.stderr, "Error: bad dog!"
2493
2494As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002495evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002496
2497 print >> None, "Hello world"
2498
2499is equivalent to
2500
2501 print "Hello world"
2502
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002503Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002504
2505
2506Optional Collection of Cyclical Garbage
2507---------------------------------------
2508
2509Python is now equipped with a garbage collector that can hunt down
2510cyclical references between Python objects. It's no replacement for
2511reference counting; in fact, it depends on the reference counts being
2512correct, and decides that a set of objects belong to a cycle if all
2513their reference counts can be accounted for from their references to
2514each other. This devious scheme was first proposed by Eric Tiedemann,
2515and brought to implementation by Neil Schemenauer.
2516
2517There's a module "gc" that lets you control some parameters of the
2518garbage collection. There's also an option to the configure script
2519that lets you enable or disable the garbage collection. In 2.0b1,
2520it's on by default, so that we (hopefully) can collect decent user
2521experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002522performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002523off by default in the final 2.0 release.
2524
2525
2526Smaller Changes
2527---------------
2528
2529A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2530map(None, seq1, seq2, ...) when the sequences have the same length;
2531i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2532the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002533zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002534
2535sys.version_info is a tuple (major, minor, micro, level, serial).
2536
2537Dictionaries have an odd new method, setdefault(key, default).
2538dict.setdefault(key, default) returns dict[key] if it exists; if not,
2539it sets dict[key] to default and returns that value. Thus:
2540
2541 dict.setdefault(key, []).append(item)
2542
2543does the same work as this common idiom:
2544
2545 if not dict.has_key(key):
2546 dict[key] = []
2547 dict[key].append(item)
2548
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002549There are two new variants of SyntaxError that are raised for
2550indentation-related errors: IndentationError and TabError.
2551
2552Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2553escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002554
2555The limits on the size of expressions and file in Python source code
2556have been raised from 2**16 to 2**32. Previous versions of Python
2557were limited because the maximum argument size the Python VM accepted
2558was 2**16. This limited the size of object constructor expressions,
2559e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2560limit was raised thanks to a patch by Charles Waldman that effectively
2561fixes the problem. It is now much more likely that you will be
2562limited by available memory than by an arbitrary limit in Python.
2563
2564The interpreter's maximum recursion depth can be modified by Python
2565programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2566limit is the maximum number of recursive calls that can be made by
2567Python code. The limit exists to prevent infinite recursion from
2568overflowing the C stack and causing a core dump. The default value is
25691000. The maximum safe value for a particular platform can be found
2570by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002571
2572New Modules and Packages
2573------------------------
2574
2575atexit - for registering functions to be called when Python exits.
2576
2577imputil - Greg Stein's alternative API for writing custom import
2578hooks.
2579
2580pyexpat - an interface to the Expat XML parser, contributed by Paul
2581Prescod.
2582
2583xml - a new package with XML support code organized (so far) in three
2584subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2585would fill a volume. There's a special feature whereby a
2586user-installed package named _xmlplus overrides the standard
2587xmlpackage; this is intended to give the XML SIG a hook to distribute
2588backwards-compatible updates to the standard xml package.
2589
2590webbrowser - a platform-independent API to launch a web browser.
2591
2592
Guido van Rossume905e952000-09-05 12:42:46 +00002593Changed Modules
2594---------------
2595
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002596array -- new methods for array objects: count, extend, index, pop, and
2597remove
2598
2599binascii -- new functions b2a_hex and a2b_hex that convert between
2600binary data and its hex representation
2601
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002602calendar -- Many new functions that support features including control
2603over which day of the week is the first day, returning strings instead
2604of printing them. Also new symbolic constants for days of week,
2605e.g. MONDAY, ..., SUNDAY.
2606
2607cgi -- FieldStorage objects have a getvalue method that works like a
2608dictionary's get method and returns the value attribute of the object.
2609
2610ConfigParser -- The parser object has new methods has_option,
2611remove_section, remove_option, set, and write. They allow the module
2612to be used for writing config files as well as reading them.
2613
2614ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002615optionally support the RFC 959 REST command.
2616
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002617gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002618
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002619httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2620the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002621
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002622locale -- implement getdefaultlocale for Win32 and Macintosh
2623
2624marshal -- no longer dumps core when marshaling deeply nested or
2625recursive data structures
2626
2627os -- new functions isatty, seteuid, setegid, setreuid, setregid
2628
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002629os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2630support under Unix.
2631
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002632os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002633
2634os.path -- fix semantics of os.path.commonprefix
2635
2636smtplib -- support for sending very long messages
2637
2638socket -- new function getfqdn()
2639
2640readline -- new functions to read, write and truncate history files.
2641The readline section of the library reference manual contains an
2642example.
2643
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002644select -- add interface to poll system call
2645
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002646shutil -- new copyfileobj function
2647
2648SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2649HTTP server.
2650
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002651Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002652
2653urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002654e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002655
2656whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002657
2658
2659Obsolete Modules
2660----------------
2661
2662None. However note that 1.6 made a whole slew of modules obsolete:
2663stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2664poly, zmod, strop, util, whatsound.
2665
2666
2667Changed, New, Obsolete Tools
2668----------------------------
2669
Tim Peters8b092332000-09-05 20:15:25 +00002670None.
Guido van Rossume905e952000-09-05 12:42:46 +00002671
2672
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002673C-level Changes
2674---------------
2675
2676Several cleanup jobs were carried out throughout the source code.
2677
2678All C code was converted to ANSI C; we got rid of all uses of the
2679Py_PROTO() macro, which makes the header files a lot more readable.
2680
2681Most of the portability hacks were moved to a new header file,
2682pyport.h; several other new header files were added and some old
2683header files were removed, in an attempt to create a more rational set
2684of header files. (Few of these ever need to be included explicitly;
2685they are all included by Python.h.)
2686
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002687Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002688and Win64, especially for the new Intel Itanium processor. Mick also
2689added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002690
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002691The C APIs to return an object's size have been update to consistently
2692use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2693previous versions, the abstract interfaces used PyXXX_Length and the
2694concrete interfaces used PyXXX_Size. The old names,
2695e.g. PyObject_Length, are still available for backwards compatibility
2696at the API level, but are deprecated.
2697
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002698The PyOS_CheckStack function has been implemented on Windows by
2699Fredrik Lundh. It prevents Python from failing with a stack overflow
2700on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002701
2702The GC changes resulted in creation of two new slots on object,
2703tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002704the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002705
2706The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002707C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002708
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002709PyErr_Format has been updated to automatically calculate the size of
2710the buffer needed to hold the formatted result string. This change
2711prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002712
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002713New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002714
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002715PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2716that are the same as their non-Ex counterparts except they take an
2717extra flag argument that tells them to close the file when done.
2718
2719XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002720
Tim Peters8b092332000-09-05 20:15:25 +00002721
2722Windows Changes
2723---------------
2724
2725New popen2/popen3/peopen4 in os module (see Changed Modules above).
2726
2727os.popen is much more usable on Windows 95 and 98. See Microsoft
2728Knowledge Base article Q150956. The Win9x workaround described there
2729is implemented by the new w9xpopen.exe helper in the root of your
2730Python installation. Note that Python uses this internally; it is not
2731a standalone program.
2732
2733Administrator privileges are no longer required to install Python
2734on Windows NT or Windows 2000. If you have administrator privileges,
2735Python's registry info will be written under HKEY_LOCAL_MACHINE.
2736Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002737under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002738uses of Python, but will prevent some advanced uses from working
2739(for example, running a Python script as an NT service, or possibly
2740from CGI).
2741
2742[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2743installer; instead, it installs the needed Tcl/Tk files directly in the
2744Python directory. If you already have a Tcl/Tk installation, this
2745wastes some disk space (about 4 Megs) but avoids problems with
2746conflicting Tcl/Tk installations, and makes it much easier for Python
2747to ensure that Tcl/Tk can find all its files.
2748
2749[This was new in 1.6] The Windows installer now installs by default in
2750\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2751
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002752
2753Updates to the changes between 1.5.2 and 1.6
2754--------------------------------------------
2755
2756The 1.6 NEWS file can't be changed after the release is done, so here
2757is some late-breaking news:
2758
2759New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2760and changes to getlocale() and setlocale().
2761
2762The new module is now enabled per default.
2763
2764It is not true that the encodings codecs cannot be used for normal
2765strings: the string.encode() (which is also present on 8-bit strings
2766!) allows using them for 8-bit strings too, e.g. to convert files from
2767cp1252 (Windows) to latin-1 or vice-versa.
2768
2769Japanese codecs are available from Tamito KAJIYAMA:
2770http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2771
2772
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002773======================================================================