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Tim Petersf553f892001-05-01 20:45:31 +00001What's New in Python 2.2a0?
2===========================
3
4Core
Tim Petersa814db52001-05-14 07:05:58 +00005
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00006- The UTF-16 codec was modified to be more RFC compliant. It will now
7 only remove BOM characters at the start of the string and then
8 only if running in native mode (UTF-16-LE and -BE won't remove a
9 leading BMO character).
10
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000011- Strings now have a new method .decode() to complement the already
12 existing .encode() method. These two methods provide direct access
13 to the corresponding decoders and encoders of the registered codecs.
14
15 To enhance the usability of the .encode() method, the special
16 casing of Unicode object return values was dropped (Unicode objects
17 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +000018
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000019 Both methods will now return whatever the codec in charge of the
20 requested encoding returns as object, e.g. Unicode codecs will
21 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
22 will return u"äöü"). This enables codec writer to create codecs
23 for various simple to use conversions.
24
25 New codecs were added to demonstrate these new features (the .encode()
26 and .decode() columns indicate the type of the returned objects):
27
28 Name | .encode() | .decode() | Description
29 ----------------------------------------------------------------------
30 uu | string | string | UU codec (e.g. for email)
31 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +000032 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000033 zlib | string | string | zlib compression
34 hex | string | string | 2-byte hex codec
35 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
36
Mark Hammond2a0af792001-05-14 03:09:36 +000037- Some operating systems now support the concept of a default Unicode
38 encoding for file system operations. Notably, Windows supports 'mbcs'
39 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +000040 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000041 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000042
43 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000044 functions that return filenames (such as os.listdir()) to return Python
45 string objects pre-encoded using the default file system encoding for
46 the platform. As this encoding is likely to be different from Python's
47 default encoding, converting this name to a Unicode object before passing
48 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000049 would attempt to use its default encoding (generally ASCII) rather than
50 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000051
Tim Petersa814db52001-05-14 07:05:58 +000052 In general, this change simply removes surprises when working with
53 Unicode and the file system, making these operations work as you expect,
54 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +000055 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +000056
Tim Peters61dff2b2001-05-08 15:43:37 +000057- Float (and complex) literals in source code were evaluated to full
58 precision only when running from a .py file; the same code loaded from a
59 .pyc (or .pyo) file could suffer numeric differences starting at about the
60 12th significant decimal digit. For example, on a machine with IEEE-754
61 floating arithmetic,
62
63 x = 9007199254740992.0
64 print long(x)
65
66 printed 9007199254740992 if run directly from .py, but 9007199254740000
67 if from a compiled (.pyc or .pyo) file. This was due to marshal using
68 str(float) instead of repr(float) when building code objects. marshal
69 now uses repr(float) instead, which should reproduce floats to full
70 machine precision (assuming the platform C float<->string I/O conversion
71 functions are of good quality).
72
73 This may cause floating-point results to change in some cases, and
74 usually for the better, but may also cause numerically unstable
75 algorithms to break.
76
Tim Peters2f228e72001-05-13 00:19:31 +000077- The implementation of dicts suffers fewer collisions, which has speed
78 benefits. However, the order in which dict entries appear in dict.keys(),
79 dict.values() and dict.items() may differ from previous releases for a
80 given dict. Nothing is defined about this order, so no program should
81 rely on it. Nevertheless, it's easy to write test cases that rely on the
82 order by accident, typically because of printing the str() or repr() of a
83 dict to an "expected results" file. See Lib/test/test_support.py's new
84 sortdict(dict) function for a simple way to display a dict in sorted
85 order.
86
Tim Peters7a3bfc32001-06-12 01:22:22 +000087- Many other small changes to dicts were made, resulting in faster
88 operation along the most common code paths.
89
Guido van Rossum10315822001-05-01 20:54:30 +000090- Dictionary objects now support the "in" operator: "x in dict" means
91 the same as dict.has_key(x).
92
Barry Warsaw51acc8d2001-06-26 20:12:50 +000093- The update() method of dictionaries now accepts generic mapping
94 objects. Specifically the argument object must support the .keys()
95 and __getitem__() methods. This allows you to say, for example,
96 {}.update(UserDict())
97
Guido van Rossum10315822001-05-01 20:54:30 +000098- Iterators were added; this is a generalized way of providing values
99 to a for loop. See PEP 234. There's a new built-in function iter()
100 to return an iterator. There's a new protocol to get the next value
101 from an iterator using the next() method (in Python) or the
102 tp_iternext slot (in C). There's a new protocol to get iterators
103 using the __iter__() method (in Python) or the tp_iter slot (in C).
104 Iterating (i.e. a for loop) over a dictionary generates its keys.
105 Iterating over a file generates its lines.
106
Tim Petersf553f892001-05-01 20:45:31 +0000107- The following functions were generalized to work nicely with iterator
108 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000109 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000110 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
111 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000112 join() method of strings
113 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000114 'x in y' and 'x not in y' (PySequence_Contains() in C API)
115 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000116 right-hand side of assignment statements with multiple targets, such as
117 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000118
Tim Petersd85e1022001-05-11 21:51:48 +0000119- Accessing module attributes is significantly faster (for example,
120 random.random or os.path or yourPythonModule.yourAttribute).
121
Tim Peterse63415e2001-05-08 04:38:29 +0000122- Comparing dictionary objects via == and != is faster, and now works even
123 if the keys and values don't support comparisons other than ==.
124
Tim Peters95bf9392001-05-10 08:32:44 +0000125- Comparing dictionaries in ways other than == and != is slower: there were
126 insecurities in the dict comparison implementation that could cause Python
127 to crash if the element comparison routines for the dict keys and/or
128 values mutated the dicts. Making the code bulletproof slowed it down.
129
Tim Peterseb28ef22001-06-02 05:27:19 +0000130- Collisions in dicts are resolved via a new approach, which can help
131 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000132 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000133 faster now. Thanks to Christian Tismer for pointing out the cause and
134 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000135
Tim Peters52e155e2001-06-16 05:42:57 +0000136- repr() is much faster for large containers (dict, list, tuple).
137
138
Tim Petersa814db52001-05-14 07:05:58 +0000139Library
140
Guido van Rossum643d3912001-07-05 14:46:25 +0000141- The xrange() object is simplified: it no longer supports slicing,
142 repetition, comparisons, efficient 'in' checking, the tolist()
143 method, or the start, stop and step attributes. See PEP 260.
144
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000145- A new function fnmatch.filter to filter lists of file names was added.
146
Barry Warsawffd674d2001-05-22 16:00:10 +0000147- calendar.py uses month and day names based on the current locale.
148
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000149- strop is now *really* obsolete (this was announced before with 1.6),
150 and issues DeprecationWarning when used (except for the four items
151 that are still imported into string.py).
152
Tim Petersa814db52001-05-14 07:05:58 +0000153- Cookie.py now sorts key+value pairs by key in output strings.
154
155- pprint.isrecursive(object) didn't correctly identify recursive objects.
156 Now it does.
157
Tim Peters95b3f782001-05-14 18:39:41 +0000158- pprint functions now much faster for large containers (tuple, list, dict).
159
Tim Peters7b9542a2001-06-10 23:40:19 +0000160- New 'q' and 'Q' format codes in the struct module, corresponding to C
161 types "long long" and "unsigned long long" (on Windows, __int64). In
162 native mode, these can be used only when the platform C compiler supports
163 these types (when HAVE_LONG_LONG is #define'd by the Python config
164 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000165 In standard mode, 'q' and 'Q' are supported on all platforms, and are
166 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000167
Guido van Rossum83213cc2001-06-12 16:48:52 +0000168- The site module installs a new built-in function 'help' that invokes
169 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
170 it displays a message reminding the user to use 'help()' or
171 'help(object)'.
172
Tim Petersa814db52001-05-14 07:05:58 +0000173Tests
174
175- New test_mutants.py runs dict comparisons where the key and value
176 comparison operators mutute the dicts randomly during comparison. This
177 rapidly causes Python to crash under earlier releases (not for the faint
178 of heart: it can also cause Win9x to freeze or reboot!).
179
180- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000181 pprint.isreadable() return sensible results. Also verifies that simple
182 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000183
Tim Peters58e0a8c2001-05-14 22:32:33 +0000184New platforms
185
186- Python should compile and run out of the box using the Borland C
187 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000188
Tim Peters4324aa32001-05-28 22:30:08 +0000189C API
190
191- Removed the unused last_is_sticky argument from the internal
192 _PyTuple_Resize(). If this affects you, you were cheating.
193
194
Guido van Rossumffe13be2001-04-16 18:46:45 +0000195What's New in Python 2.1 (final)?
196=================================
197
198We only changed a few things since the last release candidate, all in
199Python library code:
200
201- A bug in the locale module was fixed that affected locales which
202 define no grouping for numeric formatting.
203
204- A few bugs in the weakref module's implementations of weak
205 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
206 and the test suite was updated to check for these bugs.
207
208- An old bug in the os.path.walk() function (introduced in Python
209 2.0!) was fixed: a non-existent file would cause an exception
210 instead of being ignored.
211
212- Fixed a few bugs in the new symtable module found by Neil Norwitz's
213 PyChecker.
214
215
Guido van Rossum5b08f132001-04-16 02:05:23 +0000216What's New in Python 2.1c2?
217===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000218
Guido van Rossum5b08f132001-04-16 02:05:23 +0000219A flurry of small changes, and one showstopper fixed in the nick of
220time made it necessary to release another release candidate. The list
221here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000222
Guido van Rossum5b08f132001-04-16 02:05:23 +0000223Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000224
Guido van Rossum5b08f132001-04-16 02:05:23 +0000225- Tim discovered a nasty bug in the dictionary code, caused by
226 PyDict_Next() calling dict_resize(), and the GC code's use of
227 PyDict_Next() violating an assumption in dict_items(). This was
228 fixed with considerable amounts of band-aid, but the net effect is a
229 saner and more robust implementation.
230
231- Made a bunch of symbols static that were accidentally global.
232
233Build and Ports
234
235- The setup.py script didn't check for a new enough version of zlib
236 (1.1.3 is needed). Now it does.
237
238- Changed "make clean" target to also remove shared libraries.
239
240- Added a more general warning about the SGI Irix optimizer to README.
241
242Library
243
244- Fix a bug in urllib.basejoin("http://host", "../file.html") which
245 omitted the slash between host and file.html.
246
247- The mailbox module's _Mailbox class contained a completely broken
248 and undocumented seek() method. Ripped it out.
249
250- Fixed a bunch of typos in various library modules (urllib2, smtpd,
251 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
252
253- Fixed a few last-minute bugs in unittest.
254
255Extensions
256
257- Reverted the patch to the OpenSSL code in socketmodule.c to support
258 RAND_status() and the EGD, and the subsequent patch that tried to
259 fix it for pre-0.9.5 versions; the problem with the patch is that on
260 some systems it issues a warning whenever socket is imported, and
261 that's unacceptable.
262
263Tests
264
265- Fixed the pickle tests to work with "import test.test_pickle".
266
267- Tweaked test_locale.py to actually run the test Windows.
268
269- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
270 not "wb" (which is not a valid mode at all).
271
272- Fix pstats browser crashes. Import readline if it exists to make
273 the user interface nicer.
274
275- Add "import thread" to the top of test modules that import the
276 threading module (test_asynchat and test_threadedtempfile). This
277 prevents test failures caused by a broken threading module resulting
278 from a previously caught failed import.
279
280- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
281 needed on some platforms (e.g. Solaris 8) when the tests are run
282 twice in succession.
283
284- Skip rather than fail test_sunaudiodev if no audio device is found.
285
286
287What's New in Python 2.1c1?
288===========================
289
290This list was significantly updated when 2.1c2 was released; the 2.1c1
291release didn't mention most changes that were actually part of 2.1c1:
292
293Legal
294
295- Copyright was assigned to the Python Software Foundation (PSF) and a
296 PSF license (very similar to the CNRI license) was added.
297
298- The CNRI copyright notice was updated to include 2001.
299
300Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000301
Guido van Rossumc9932722001-04-12 02:31:27 +0000302- After a public outcry, assignment to __debug__ is no longer illegal;
303 instead, a warning is issued. It will become illegal in 2.2.
304
Guido van Rossum5b08f132001-04-16 02:05:23 +0000305- Fixed a core dump with "%#x" % 0, and changed the semantics so that
306 "%#x" now always prepends "0x", even if the value is zero.
307
308- Fixed some nits in the bytecode compiler.
309
310- Fixed core dumps when calling certain kinds of non-functions.
311
312- Fixed various core dumps caused by reference count bugs.
313
314Build and Ports
315
316- Use INSTALL_SCRIPT to install script files.
317
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000318- New port: SCO Unixware 7, by Billy G. Allie.
319
Guido van Rossum5b08f132001-04-16 02:05:23 +0000320- Updated RISCOS port.
321
322- Updated BeOS port and notes.
323
324- Various other porting problems resolved.
325
326Library
327
328- The TERMIOS and SOCKET modules are now truly obsolete and
329 unnecessary. Their symbols are incorporated in the termios and
330 socket modules.
331
332- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
333 better tests for pickling.
334
335- threading: make Condition.wait() robust against KeyboardInterrupt.
336
337- zipfile: add support to zipfile to support opening an archive
338 represented by an open file rather than a file name. Fix bug where
339 the archive was not properly closed. Fixed a bug in this bugfix
340 where flush() was called for a read-only file.
341
342- imputil: added an uninstall() method to the ImportManager.
343
344- Canvas: fixed bugs in lower() and tkraise() methods.
345
346- SocketServer: API change (added overridable close_request() method)
347 so that the TCP server can explicitly close the request.
348
349- pstats: Eric Raymond added a simple interactive statistics browser,
350 invoked when the module is run as a script.
351
352- locale: fixed a problem in format().
353
354- webbrowser: made it work when the BROWSER environment variable has a
355 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
356 KDE 2. Fixed some other nits.
357
358- unittest: changes to allow using a different exception than
359 AssertionError, and added a few more function aliases. Some other
360 small changes.
361
362- urllib, urllib2: fixed redirect problems and a coupleof other nits.
363
364- asynchat: fixed a critical bug in asynchat that slipped through the
365 2.1b2 release. Fixed another rare bug.
366
367- Fix some unqualified except: clauses (always a bad code example).
368
369XML
370
371- pyexpat: new API get_version_string().
372
373- Fixed some minidom bugs.
374
375Extensions
376
377- Fixed a core dump in _weakref. Removed the weakref.mapping()
378 function (it adds nothing to the API).
379
380- Rationalized the use of header files in the readline module, to make
381 it compile (albeit with some warnings) with the very recent readline
382 4.2, without breaking for earlier versions.
383
384- Hopefully fixed a buffering problem in linuxaudiodev.
385
386- Attempted a fix to make the OpenSSL support in the socket module
387 work again with pre-0.9.5 versions of OpenSSL.
388
389Tests
390
391- Added a test case for asynchat and asyncore.
392
393- Removed coupling between tests where one test failing could break
394 another.
395
396Tools
397
398- Ping added an interactive help browser to pydoc, fixed some nits
399 in the rest of the pydoc code, and added some features to his
400 inspect module.
401
402- An updated python-mode.el version 4.1 which integrates Ken
403 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
404 much nicer in XEmacs and Emacs. When stepping through your program
405 with pdb, in either the shell window or the *Python* window, the
406 source file and line will be tracked by an arrow. Very cool!
407
408- IDLE: syntax warnings in interactive mode are changed into errors.
409
410- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000411 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000412
413- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000414
Barry Warsaw11e89c72001-04-11 20:37:57 +0000415
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000416What's New in Python 2.1 beta 2?
417================================
418
Guido van Rossum053ae352001-03-22 14:17:21 +0000419(Unlisted are many fixed bugs, more documentation, etc.)
420
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000421Core language, builtins, and interpreter
422
Guido van Rossum053ae352001-03-22 14:17:21 +0000423- The nested scopes work (enabled by "from __future__ import
424 nested_scopes") is completed; in particular, the future now extends
425 into code executed through exec, eval() and execfile(), and into the
426 interactive interpreter.
427
428- When calling a base class method (e.g. BaseClass.__init__(self)),
429 this is now allowed even if self is not strictly spoken a class
430 instance (e.g. when using metaclasses or the Don Beaudry hook).
431
432- Slice objects are now comparable but not hashable; this prevents
433 dict[:] from being accepted but meaningless.
434
435- Complex division is now calculated using less braindead algorithms.
436 This doesn't change semantics except it's more likely to give useful
437 results in extreme cases. Complex repr() now uses full precision
438 like float repr().
439
440- sgmllib.py now calls handle_decl() for simple <!...> declarations.
441
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000442- It is illegal to assign to the name __debug__, which is set when the
443 interpreter starts. It is effectively a compile-time constant.
444
445- A warning will be issued if a global statement for a variable
446 follows a use or assignment of that variable.
447
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000448Standard library
449
Guido van Rossum053ae352001-03-22 14:17:21 +0000450- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
451 inspired by JUnit), is now part of the standard library. You now
452 have a choice of two testing frameworks: unittest requires you to
453 write testcases as separate code, doctest gathers them from
454 docstrings. Both approaches have their advantages and
455 disadvantages.
456
457- A new module Tix was added, which wraps the Tix extension library
458 for Tk. With that module, it is not necessary to statically link
459 Tix with _tkinter, since Tix will be loaded with Tcl's "package
460 require" command. See Demo/tix/.
461
462- tzparse.py is now obsolete.
463
464- In gzip.py, the seek() and tell() methods are removed -- they were
465 non-functional anyway, and it's better if callers can test for their
466 existence with hasattr().
467
468Python/C API
469
470- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
471 that's already in the dictionary during a PyDict_Next() iteration.
472 This used to fail occasionally when a dictionary resize operation
473 could be triggered that would rehash all the keys. All other
474 modifications to the dictionary are still off-limits during a
475 PyDict_Next() iteration!
476
477- New extended APIs related to passing compiler variables around.
478
479- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
480 implement isinstance() and issubclass().
481
482- Py_BuildValue() now has a "D" conversion to create a Python complex
483 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000484
Fred Drake4e262a92001-03-22 18:26:47 +0000485- Extensions types which support weak references must now set the
486 field allocated for the weak reference machinery to NULL themselves;
487 this is done to avoid the cost of checking each object for having a
488 weakly referencable type in PyObject_INIT(), since most types are
489 not weakly referencable.
490
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000491- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
492 free variables and cell variables to and from the frame's f_locals.
493
494- Variants of several functions defined in pythonrun.h have been added
495 to support the nested_scopes future statement. The variants all end
496 in Flags and take an extra argument, a PyCompilerFlags *; examples:
497 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
498 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000499 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000500
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000501Distutils
502
503- the sdist command now writes a PKG-INFO file, as described in PEP 241,
504 into the release tree.
505
Tim Peters0e57abf2001-05-02 07:39:38 +0000506- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000507 (an uninstaller, more customization of the installer's display)
508
509- from Jack Jansen: added Mac-specific code to generate a dialog for
510 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000511 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000512 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000513
514- added 'platforms' and 'keywords' to the set of metadata that can be
515 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000516
517- applied patches from Jason Tishler to make the compiler class work with
518 Cygwin.
519
520
Tim Peters2fe289a2001-03-01 22:19:38 +0000521What's New in Python 2.1 beta 1?
522================================
Tim Petersd66595f2001-02-04 03:09:53 +0000523
524Core language, builtins, and interpreter
525
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000526- Following an outcry from the community about the amount of code
527 broken by the nested scopes feature introduced in 2.1a2, we decided
528 to make this feature optional, and to wait until Python 2.2 (or at
529 least 6 months) to make it standard. The option can be enabled on a
530 per-module basis by adding "from __future__ import nested_scopes" at
531 the beginning of a module (before any other statements, but after
532 comments and an optional docstring). See PEP 236 (Back to the
533 __future__) for a description of the __future__ statement. PEP 227
534 (Statically Nested Scopes) has been updated to reflect this change,
535 and to clarify the semantics in a number of endcases.
536
537- The nested scopes code, when enabled, has been hardened, and most
538 bugs and memory leaks in it have been fixed.
539
540- Compile-time warnings are now generated for a number of conditions
541 that will break or change in meaning when nested scopes are enabled:
542
543 - Using "from...import *" or "exec" without in-clause in a function
544 scope that also defines a lambda or nested function with one or
545 more free (non-local) variables. The presence of the import* or
546 bare exec makes it impossible for the compiler to determine the
547 exact set of local variables in the outer scope, which makes it
548 impossible to determine the bindings for free variables in the
549 inner scope. To avoid the warning about import *, change it into
550 an import of explicitly name object, or move the import* statement
551 to the global scope; to avoid the warning about bare exec, use
552 exec...in... (a good idea anyway -- there's a possibility that
553 bare exec will be deprecated in the future).
554
555 - Use of a global variable in a nested scope with the same name as a
556 local variable in a surrounding scope. This will change in
557 meaning with nested scopes: the name in the inner scope will
558 reference the variable in the outer scope rather than the global
559 of the same name. To avoid the warning, either rename the outer
560 variable, or use a global statement in the inner function.
561
Neil Schemenauera35c6882001-02-27 04:45:05 +0000562- An optional object allocator has been included. This allocator is
563 optimized for Python objects and should be faster and use less memory
564 than the standard system allocator. It is not enabled by default
565 because of possible thread safety problems. The allocator is only
566 protected by the Python interpreter lock and it is possible that some
567 extension modules require a thread safe allocator. The object
568 allocator can be enabled by providing the "--with-pymalloc" option to
569 configure.
570
Tim Petersd66595f2001-02-04 03:09:53 +0000571Standard library
572
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000573- pyexpat now detects the expat version if expat.h defines it. A
574 number of additional handlers are provided, which are only available
575 since expat 1.95. In addition, the methods SetParamEntityParsing and
576 GetInputContext of Parser objects are available with 1.95.x
577 only. Parser objects now provide the ordered_attributes and
578 specified_attributes attributes. A new module expat.model was added,
579 which offers a number of additional constants if 1.95.x is used.
580
581- xml.dom offers the new functions registerDOMImplementation and
582 getDOMImplementation.
583
584- xml.dom.minidom offers a toprettyxml method. A number of DOM
585 conformance issues have been resolved. In particular, Element now
586 has an hasAttributes method, and the handling of namespaces was
587 improved.
588
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000589- Ka-Ping Yee contributed two new modules: inspect.py, a module for
590 getting information about live Python code, and pydoc.py, a module
591 for interactively converting docstrings to HTML or text.
592 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000593 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000594 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
595 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000596
Tim Peters1eff7962001-03-01 02:31:33 +0000597- New library module difflib.py, primarily packaging the SequenceMatcher
598 class at the heart of the popular ndiff.py file-comparison tool.
599
600- doctest.py (a framework for verifying Python code examples in docstrings)
601 is now part of the std library.
602
Tim Petersd66595f2001-02-04 03:09:53 +0000603Windows changes
604
Guido van Rossume3955a82001-03-02 14:05:59 +0000605- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
606 small GUI that lets you browse the module docstrings using your
607 default web browser.
608
Tim Peters1eff7962001-03-01 02:31:33 +0000609- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
610 Platforms) is implemented. See
611
612 http://python.sourceforge.net/peps/pep-0235.html
613
614 for full details, especially the "Current Lower-Left Semantics" section.
615 The new Windows import rules are simpler than before:
616
617 A. If the PYTHONCASEOK environment variable exists, same as
618 before: silently accept the first case-insensitive match of any
619 kind; raise ImportError if none found.
620
621 B. Else search sys.path for the first case-sensitive match; raise
622 ImportError if none found.
623
624 The same rules have been implented on other platforms with case-
625 insensitive but case-preserving filesystems too (including Cygwin, and
626 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000627
Tim Peters25a9ce32001-02-19 07:06:36 +0000628- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
629 what it's supposed to do (and does do under NT and 2000) via direct
630 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000631 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000632 all Win9x systems before.
633
Tim Peters1eff7962001-03-01 02:31:33 +0000634- Build: Subproject _test (effectively) renamed to _testcapi.
635
Tim Peters2fe289a2001-03-01 22:19:38 +0000636New platforms
637
638- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
639 Thanks to Steven Majewski!
640
641- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
642 Tishler!
643
Guido van Rossum9089b272001-03-02 06:49:50 +0000644- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
645 Schwertberger! See RISCOS/README for more information -- it seems
646 that because of the bizarre filename conventions on RISCOS, no port
647 to that platform is easy. Note that the new variable os.endsep is
648 silently supported in order to make life easier on this platform,
649 but we don't advertise it because it's not worth for most folks to
650 care about RISCOS portability.
651
Tim Peters25a9ce32001-02-19 07:06:36 +0000652
Tim Petersd7b5e882001-01-25 03:36:26 +0000653What's New in Python 2.1 alpha 2?
654=================================
Tim Peters40ead762001-01-27 05:35:26 +0000655
Tim Petersd7b5e882001-01-25 03:36:26 +0000656Core language, builtins, and interpreter
657
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000658- Scopes nest. If a name is used in a function or class, but is not
659 local, the definition in the nearest enclosing function scope will
660 be used. One consequence of this change is that lambda statements
661 could reference variables in the namespaces where the lambda is
662 defined. In some unusual cases, this change will break code.
663
664 In all previous version of Python, names were resolved in exactly
665 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000666 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000667 function A is defined within a function B, the names bound in B are
668 not visible in A. The new rules make names bound in B visible in A,
669 unless A contains a name binding that hides the binding in B.
670
671 Section 4.1 of the reference manual describes the new scoping rules
672 in detail. The test script in Lib/test/test_scope.py demonstrates
673 some of the effects of the change.
674
675 The new rules will cause existing code to break if it defines nested
676 functions where an outer function has local variables with the same
677 name as globals or builtins used by the inner function. Example:
678
679 def munge(str):
680 def helper(x):
681 return str(x)
682 if type(str) != type(''):
683 str = helper(str)
684 return str.strip()
685
686 Under the old rules, the name str in helper() is bound to the
687 builtin function str(). Under the new rules, it will be bound to
688 the argument named str and an error will occur when helper() is
689 called.
690
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000691- The compiler will report a SyntaxError if "from ... import *" occurs
692 in a function or class scope. The language reference has documented
693 that this case is illegal, but the compiler never checked for it.
694 The recent introduction of nested scope makes the meaning of this
695 form of name binding ambiguous. In a future release, the compiler
696 may allow this form when there is no possibility of ambiguity.
697
Tim Peters40ead762001-01-27 05:35:26 +0000698- repr(string) is easier to read, now using hex escapes instead of octal,
699 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
700
701 >>> "\texample \r\n" + chr(0) + chr(255)
702 '\texample \r\n\x00\xff' # in 2.1
703 '\011example \015\012\000\377' # in 2.0
704
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000705- Functions are now compared and hashed by identity, not by value, since
706 the func_code attribute is writable.
707
Fred Drakefb9d7122001-02-01 20:00:40 +0000708- Weak references (PEP 205) have been added. This involves a few
709 changes in the core, an extension module (_weakref), and a Python
710 module (weakref). The weakref module is the public interface. It
711 includes support for "explicit" weak references, proxy objects, and
712 mappings with weakly held values.
713
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000714- A 'continue' statement can now appear in a try block within the body
715 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000716 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000717
Tim Petersd7b5e882001-01-25 03:36:26 +0000718Standard library
719
Barry Warsaw30dbd142001-01-31 22:14:01 +0000720- mailbox.py now has a new class, PortableUnixMailbox which is
721 identical to UnixMailbox but uses a more portable scheme for
722 determining From_ separators. Also, the constructors for all the
723 classes in this module have a new optional `factory' argument, which
724 is a callable used when new message classes must be instantiated by
725 the next() method.
726
Tim Petersd7b5e882001-01-25 03:36:26 +0000727- random.py is now self-contained, and offers all the functionality of
728 the now-deprecated whrandom.py. See the docs for details. random.py
729 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000730 and restoring the internal state of the generator; and jumpahead(n),
731 for quickly forcing the internal state to be the same as if n calls to
732 random() had been made. The latter is particularly useful for multi-
733 threaded programs, creating one instance of the random.Random() class for
734 each thread, then using .jumpahead() to force each instance to use a
735 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000736
Tim Peters0de88fc2001-02-01 04:59:18 +0000737- random.py's seed() function is new. For bit-for-bit compatibility with
738 prior releases, use the whseed function instead. The new seed function
739 addresses two problems: (1) The old function couldn't produce more than
740 about 2**24 distinct internal states; the new one about 2**45 (the best
741 that can be done in the Wichmann-Hill generator). (2) The old function
742 sometimes produced identical internal states when passed distinct
743 integers, and there was no simple way to predict when that would happen;
744 the new one guarantees to produce distinct internal states for all
745 arguments in [0, 27814431486576L).
746
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000747- The socket module now supports raw packets on Linux. The socket
748 family is AF_PACKET.
749
Tim Peters9ea17ac2001-02-02 05:57:15 +0000750- test_capi.py is a start at running tests of the Python C API. The tests
751 are implemented by the new Modules/_testmodule.c.
752
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000753- A new extension module, _symtable, provides provisional access to the
754 internal symbol table used by the Python compiler. A higher-level
755 interface will be added on top of _symtable in a future release.
756
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000757- Removed the obsolete soundex module.
758
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000759- xml.dom.minidom now uses the standard DOM exceptions. Node supports
760 the isSameNode method; NamedNodeMap the get method.
761
762- xml.sax.expatreader supports the lexical handler property; it
763 generates comment, startCDATA, and endCDATA events.
764
Tim Petersee826f82001-01-31 19:39:44 +0000765Windows changes
766
767- Build procedure: the zlib project is built in a different way that
768 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000769 the zlib binary used. See PCbuild\readme.txt for details. Your old
770 zlib-related directories can be deleted; you'll need to download fresh
771 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000772
Tim Peters9ea17ac2001-02-02 05:57:15 +0000773- Build: New subproject _test for the benefit of test_capi.py (see above).
774
Tim Petersb16c56f2001-02-02 21:24:51 +0000775- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
776 interface to some Python compiler internals).
777
778- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000779 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000780
Tim Petersa3a3a032000-11-30 05:22:44 +0000781What's New in Python 2.1 alpha 1?
782=================================
783
784Core language, builtins, and interpreter
785
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000786- There is a new Unicode companion to the PyObject_Str() API
787 called PyObject_Unicode(). It behaves in the same way as the
788 former, but assures that the returned value is an Unicode object
789 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000790
Guido van Rossumf98eda02001-01-17 15:54:45 +0000791- The comparison operators support "rich comparison overloading" (PEP
792 207). C extension types can provide a rich comparison function in
793 the new tp_richcompare slot in the type object. The cmp() function
794 and the C function PyObject_Compare() first try the new rich
795 comparison operators before trying the old 3-way comparison. There
796 is also a new C API PyObject_RichCompare() (which also falls back on
797 the old 3-way comparison, but does not constrain the outcome of the
798 rich comparison to a Boolean result).
799
800 The rich comparison function takes two objects (at least one of
801 which is guaranteed to have the type that provided the function) and
802 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
803 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
804 object, which may be NotImplemented (in which case the tp_compare
805 slot function is used as a fallback, if defined).
806
807 Classes can overload individual comparison operators by defining one
808 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000809 __ge__. There are no explicit "reflected argument" versions of
810 these; instead, __lt__ and __gt__ are each other's reflection,
811 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
812 reflection (similar at the C level). No other implications are
813 made; in particular, Python does not assume that == is the Boolean
814 inverse of !=, or that < is the Boolean inverse of >=. This makes
815 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000816
817 Classes or types that want to implement (in)equality tests but not
818 the ordering operators (i.e. unordered types) should implement ==
819 and !=, and raise an error for the ordering operators.
820
Guido van Rossuma88479f2001-01-18 14:28:08 +0000821 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000822 Boolean; e.g. a matrix type might want to return a matrix of bits
823 for A < B, giving elementwise comparisons. Such types should ensure
824 that any interpretation of their value in a Boolean context raises
825 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
826 at the C level) to always raise an exception.
827
Guido van Rossuma88479f2001-01-18 14:28:08 +0000828- Complex numbers use rich comparisons to define == and != but raise
829 an exception for <, <=, > and >=. Unfortunately, this also means
830 that cmp() of two complex numbers raises an exception when the two
831 numbers differ. Since it is not mathematically meaningful to compare
832 complex numbers except for equality, I hope that this doesn't break
833 too much code.
834
Tim Peters3389f192001-02-18 08:48:49 +0000835- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000836 not defined by the language, other than that it's arbitrary but
837 consistent (see the Reference Manual). An implementation detail changed
838 in 2.1a1 such that None now compares less than any other object. Code
839 relying on this new behavior (like code that relied on the previous
840 behavior) does so at its own risk.
841
Barry Warsaw573b5412001-01-15 20:43:18 +0000842- Functions and methods now support getting and setting arbitrarily
843 named attributes (PEP 232). Functions have a new __dict__
844 (a.k.a. func_dict) which hold the function attributes. Methods get
845 and set attributes on their underlying im_func. It is a TypeError
846 to set an attribute on a bound method.
847
Guido van Rossum051e3352001-01-15 19:11:10 +0000848- The xrange() object implementation has been improved so that
849 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
850 limitation that in this case len(xrange(sys.maxint)) can't be
851 calculated, but the common idiom "for i in xrange(sys.maxint)" will
852 work fine as long as the index i doesn't actually reach 2**31.
853 (Python uses regular ints for sequence and string indices; fixing
854 that is much more work.)
855
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000856- Two changes to from...import:
857
Guido van Rossumba381232001-02-03 15:06:40 +0000858 1) "from M import X" now works even if (after loading module M)
859 sys.modules['M'] is not a real module; it's basically a getattr()
860 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000861
862 2) "from M import *" now looks for M.__all__ to decide which names to
863 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
864 filters out names starting with '_' as before. Whether or not
865 __all__ exists, there's no restriction on the type of M.
866
Guido van Rossumf61f1662001-01-10 20:13:55 +0000867- File objects have a new method, xreadlines(). This is the fastest
868 way to iterate over all lines in a file:
869
870 for line in file.xreadlines():
871 ...do something to line...
872
873 See the xreadlines module (mentioned below) for how to do this for
874 other file-like objects.
875
876- Even if you don't use file.xreadlines(), you may expect a speedup on
877 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000878 quite a bit in platform-specific ways: on systems (like Linux) that
879 support flockfile(), getc_unlocked(), and funlockfile(), those are
880 used by default. On systems (like Windows) without getc_unlocked(),
881 a complicated (but still thread-safe) method using fgets() is used by
882 default.
883
Tim Petersd52269b2001-01-25 06:23:18 +0000884 You can force use of the fgets() method by #define'ing
885 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000886 getc_unlocked()).
887
Tim Petersd52269b2001-01-25 06:23:18 +0000888 You can force fgets() not to be used by #define'ing
889 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000890 test_bufio.py fails -- and let us know if it does!).
891
892- In addition, the fileinput module, while still slower than the other
893 methods on most platforms, has been sped up too, by using
894 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000895
896- Support for run-time warnings has been added, including a new
897 command line option (-W) to specify the disposition of warnings.
898 See the description of the warnings module below.
899
900- Extensive changes have been made to the coercion code. This mostly
901 affects extension modules (which can now implement mixed-type
902 numerical operators without having to use coercion), but
903 occasionally, in boundary cases the coercion semantics have changed
904 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000905 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000906 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000907 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000908
Guido van Rossumf98eda02001-01-17 15:54:45 +0000909- In connection with the coercion changes, a new built-in singleton
910 object, NotImplemented is defined. This can be returned for
911 operations that wish to indicate they are not implemented for a
912 particular combination of arguments. From C, this is
913 Py_NotImplemented.
914
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000915- The interpreter accepts now bytecode files on the command line even
916 if they do not have a .pyc or .pyo extension. On Linux, after executing
917
Martin v. Löwise214baa2001-02-04 22:37:56 +0000918import imp,sys,string
919magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
920reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
921open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000922
923 any byte code file can be used as an executable (i.e. as an argument
924 to execve(2)).
925
Tim Peters9940b802000-12-01 07:59:35 +0000926- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000927 character. In 1.6 and earlier, they never produced a sign,
928 and raised an error if the value of the long was too large
929 to fit in a Python int. In 2.0, they produced a sign if and
930 only if too large to fit in an int. This was inconsistent
931 across platforms (because the size of an int varies across
932 platforms), and inconsistent with hex() and oct(). Example:
933
934 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000935 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000936 'ffffffbe' # in 2.0 and before, on 32-bit machines
937 >>> hex(-0x42L)
938 '-0x42L' # in all versions of Python
939
Tim Peters9940b802000-12-01 07:59:35 +0000940 The behavior of %d formats for negative Python longs remains
941 the same as in 2.0 (although in 1.6 and before, they raised
942 an error if the long didn't fit in a Python int).
943
944 %u formats don't make sense for Python longs, but are allowed
945 and treated the same as %d in 2.1. In 2.0, a negative long
946 formatted via %u produced a sign if and only if too large to
947 fit in an int. In 1.6 and earlier, a negative long formatted
948 via %u raised an error if it was too big to fit in an int.
949
Guido van Rossum3661d392000-12-12 22:10:31 +0000950- Dictionary objects have an odd new method, popitem(). This removes
951 an arbitrary item from the dictionary and returns it (in the form of
952 a (key, value) pair). This can be useful for algorithms that use a
953 dictionary as a bag of "to do" items and repeatedly need to pick one
954 item. Such algorithms normally end up running in quadratic time;
955 using popitem() they can usually be made to run in linear time.
956
Tim Peters36cdad12000-12-29 02:06:45 +0000957Standard library
958
Thomas Woutersfe385252001-01-19 23:16:56 +0000959- In the time module, the time argument to the functions strftime,
960 localtime, gmtime, asctime and ctime is now optional, defaulting to
961 the current time (in the local timezone).
962
Guido van Rossumda91f222001-01-15 16:36:08 +0000963- The ftplib module now defaults to passive mode, which is deemed a
964 more useful default given that clients are often inside firewalls
965 these days. Note that this could break if ftplib is used to connect
966 to a *server* that is inside a firewall, from outside; this is
967 expected to be a very rare situation. To fix that, you can call
968 ftp.set_pasv(0).
969
Martin v. Löwis10a27872001-01-13 09:54:41 +0000970- The module site now treats .pth files not only for path configuration,
971 but also supports extensions to the initialization code: Lines starting
972 with import are executed.
973
Guido van Rossumf61f1662001-01-10 20:13:55 +0000974- There's a new module, warnings, which implements a mechanism for
975 issuing and filtering warnings. There are some new built-in
976 exceptions that serve as warning categories, and a new command line
977 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
978 turns warnings into errors). warnings.warn(message[, category])
979 issues a warning message; this can also be called from C as
980 PyErr_Warn(category, message).
981
982- A new module xreadlines was added. This exports a single factory
983 function, xreadlines(). The intention is that this code is the
984 absolutely fastest way to iterate over all lines in an open
985 file(-like) object:
986
987 import xreadlines
988 for line in xreadlines.xreadlines(file):
989 ...do something to line...
990
991 This is equivalent to the previous the speed record holder using
992 file.readlines(sizehint). Note that if file is a real file object
993 (as opposed to a file-like object), this is equivalent:
994
995 for line in file.xreadlines():
996 ...do something to line...
997
Tim Peters36cdad12000-12-29 02:06:45 +0000998- The bisect module has new functions bisect_left, insort_left,
999 bisect_right and insort_right. The old names bisect and insort
1000 are now aliases for bisect_right and insort_right. XXX_right
1001 and XXX_left methods differ in what happens when the new element
1002 compares equal to one or more elements already in the list: the
1003 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001004 right. Code that doesn't care where equal elements end up should
1005 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001006
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001007- The new curses.panel module wraps the panel library that forms part
1008 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1009
Guido van Rossumf61f1662001-01-10 20:13:55 +00001010- The SocketServer module now sets the allow_reuse_address flag by
1011 default in the TCPServer class.
1012
1013- A new function, sys._getframe(), returns the stack frame pointer of
1014 the caller. This is intended only as a building block for
1015 higher-level mechanisms such as string interpolation.
1016
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001017- The pyexpat module supports a number of new handlers, which are
1018 available only in expat 1.2. If invocation of a callback fails, it
1019 will report an additional frame in the traceback. Parser objects
1020 participate now in garbage collection. If expat reports an unknown
1021 encoding, pyexpat will try to use a Python codec; that works only
1022 for single-byte charsets. The parser type objects is exposed as
1023 XMLParserObject.
1024
1025- xml.dom now offers standard definitions for symbolic node type and
1026 exception code constants, and a hierarchy of DOM exceptions. minidom
1027 was adjusted to use them.
1028
1029- The conformance of xml.dom.minidom to the DOM specification was
1030 improved. It detects a number of additional error cases; the
1031 previous/next relationship works even when the tree is modified;
1032 Node supports the normalize() method; NamedNodeMap, DocumentType and
1033 DOMImplementation classes were added; Element supports the
1034 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1035 method.
1036
Guido van Rossumf61f1662001-01-10 20:13:55 +00001037Build issues
1038
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001039- For Unix (and Unix-compatible) builds, configuration and building of
1040 extension modules is now greatly automated. Rather than having to
1041 edit the Modules/Setup file to indicate which modules should be
1042 built and where their include files and libraries are, a
1043 distutils-based setup.py script now takes care of building most
1044 extension modules. All extension modules built this way are built
1045 as shared libraries. Only a few modules that must be linked
1046 statically are still listed in the Setup file; you won't need to
1047 edit their configuration.
1048
1049- Python should now build out of the box on Cygwin. If it doesn't,
1050 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001051
1052- Python now always uses its own (renamed) implementation of getopt()
1053 -- there's too much variation among C library getopt()
1054 implementations.
1055
1056- C++ compilers are better supported; the CXX macro is always set to a
1057 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001058
Tim Petersd92dfe02000-12-12 01:18:41 +00001059Windows changes
1060
1061- select module: By default under Windows, a select() call
1062 can specify no more than 64 sockets. Python now boosts
1063 this Microsoft default to 512. If you need even more than
1064 that, see the MS docs (you'll need to #define FD_SETSIZE
1065 and recompile Python from source).
1066
Guido van Rossumf61f1662001-01-10 20:13:55 +00001067- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1068 subdirectory is no more!
1069
Tim Petersa3a3a032000-11-30 05:22:44 +00001070
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001071What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001072=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001073
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001074Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001075changes are in the file HISTORY. If you are making the jump directly
1076from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1077HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001078
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001079Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1080the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1081http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001082
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001083--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001084
1085======================================================================
1086
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001087What's new in 2.0 (since release candidate 1)?
1088==============================================
1089
1090Standard library
1091
1092- The copy_reg module was modified to clarify its intended use: to
1093 register pickle support for extension types, not for classes.
1094 pickle() will raise a TypeError if it is passed a class.
1095
1096- Fixed a bug in gettext's "normalize and expand" code that prevented
1097 it from finding an existing .mo file.
1098
1099- Restored support for HTTP/0.9 servers in httplib.
1100
Tim Peters989b7b92000-10-16 20:24:53 +00001101- The math module was changed to stop raising OverflowError in case of
1102 underflow, and return 0 instead in underflow cases. Whether Python
1103 used to raise OverflowError in case of underflow was platform-
1104 dependent (it did when the platform math library set errno to ERANGE
1105 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001106
1107- Fixed a bug in StringIO that occurred when the file position was not
1108 at the end of the file and write() was called with enough data to
1109 extend past the end of the file.
1110
1111- Fixed a bug that caused Tkinter error messages to get lost on
1112 Windows. The bug was fixed by replacing direct use of
1113 interp->result with Tcl_GetStringResult(interp).
1114
1115- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1116 redirect response.
1117
1118- Several changes were made to distutils: Some debugging code was
1119 removed from util. Fixed the installer used when an external zip
1120 program (like WinZip) is not found; the source code for this
1121 installer is in Misc/distutils. check_lib() was modified to behave
1122 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1123 test for whether installed modules are on sys.path was changed to
1124 use both normcase() and normpath().
1125
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001126- Several minor bugs were fixed in the xml package (the minidom,
1127 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001128
1129- The regression test driver (regrtest.py) behavior when invoked with
1130 -l changed: It now reports a count of objects that are recognized as
1131 garbage but not freed by the garbage collector.
1132
Tim Peters989b7b92000-10-16 20:24:53 +00001133- The regression test for the math module was changed to test
1134 exceptional behavior when the test is run in verbose mode. Python
1135 cannot yet guarantee consistent exception behavior across platforms,
1136 so the exception part of test_math is run only in verbose mode, and
1137 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001138
1139Internals
1140
1141- PyOS_CheckStack() has been disabled on Win64, where it caused
1142 test_sre to fail.
1143
1144Build issues
1145
1146- Changed compiler flags, so that gcc is always invoked with -Wall and
1147 -Wstrict-prototypes. Users compiling Python with GCC should see
1148 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001149 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001150 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001151
Tim Petersa3a3a032000-11-30 05:22:44 +00001152- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001153
1154Tools and other miscellany
1155
1156- The compiler in Tools/compiler was updated to support the new
1157 language features introduced in 2.0: extended print statement, list
1158 comprehensions, and augmented assignments. The new compiler should
1159 also be backwards compatible with Python 1.5.2; the compiler will
1160 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001161 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001162
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001163What's new in 2.0 release candidate 1 (since beta 2)?
1164=====================================================
1165
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001166What is release candidate 1?
1167
1168We believe that release candidate 1 will fix all known bugs that we
1169intend to fix for the 2.0 final release. This release should be a bit
1170more stable than the previous betas. We would like to see even more
1171widespread testing before the final release, so we are producing this
1172release candidate. The final release will be exactly the same unless
1173any show-stopping (or brown bag) bugs are found by testers of the
1174release candidate.
1175
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001176All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001177to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001178
1179Core language, builtins, and interpreter
1180
1181- A bug that caused crashes when __coerce__ was used with augmented
1182 assignment, e.g. +=, was fixed.
1183
1184- Raise ZeroDivisionError when raising zero to a negative number,
1185 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1186 power operator and the result of math.pow(0.0, -2.0) will vary by
1187 platform. On Linux, it raises a ValueError.
1188
1189- A bug in Unicode string interpolation was fixed that occasionally
1190 caused errors with formats including "%%". For example, the
1191 following expression "%% %s" % u"abc" no longer raises a TypeError.
1192
1193- Compilation of deeply nested expressions raises MemoryError instead
1194 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1195
1196- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1197 rendering them useless. They are now written in binary mode again.
1198
1199Standard library
1200
1201- Keyword arguments are now accepted for most pattern and match object
1202 methods in SRE, the standard regular expression engine.
1203
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001204- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001205 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001206
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001207- Several bugs in the Unicode handling and error handling in _tkinter
1208 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001209
1210- Fix memory management errors in Merge() and Tkapp_Call() routines.
1211
1212- Several changes were made to cStringIO to make it compatible with
1213 the file-like object interface and with StringIO. If operations are
1214 performed on a closed object, an exception is raised. The truncate
1215 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001216 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001217
1218- There were many changes made to the linuxaudiodev module and its
1219 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001220 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001221
1222 Note that this module is named poorly, because it should work
1223 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001224 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001225
1226 The module now raises exceptions when errors occur instead of
1227 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1228 audio) and defines a getptr() method that calls the
1229 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1230
1231- The library_version attribute, introduced in an earlier beta, was
1232 removed because it can not be supported with early versions of the C
1233 readline library, which provides no way to determine the version at
1234 compile-time.
1235
1236- The binascii module is now enabled on Win64.
1237
Tim Peters46446d62000-10-09 21:19:31 +00001238- tokenize.py no longer suffers "recursion depth" errors when parsing
1239 programs with very long string literals.
1240
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001241Internals
1242
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001243- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001244 which is called when the interpreter starts up to determine where
1245 the standard library is installed. These vulnerabilities affect all
1246 previous versions of Python and can be exploited by setting very
1247 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1248 setuid Python script, although use of the wrapper in
1249 Misc/setuid-prog.c will eliminate the vulnerability.
1250
1251- Fixed garbage collection bugs in instance creation that were
1252 triggered when errors occurred during initialization. The solution,
1253 applied in cPickle and in PyInstance_New(), is to call
1254 PyObject_GC_Init() after the initialization of the object's
1255 container attributes is complete.
1256
1257- pyexpat adds definitions of PyModule_AddStringConstant and
1258 PyModule_AddObject if the Python version is less than 2.0, which
1259 provides compatibility with PyXML on Python 1.5.2.
1260
1261- If the platform has a bogus definition for LONG_BIT (the number of
1262 bits in a long), an error will be reported at compile time.
1263
1264- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1265 collection crashes and possibly other, unreported crashes.
1266
1267- Fixed a memory leak in _PyUnicode_Fini().
1268
1269Build issues
1270
1271- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001272 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001273 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001274
1275- The mmap.PAGESIZE constant is now initialized using sysconf when
1276 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1277
1278- The md5 file should now compile on all platforms.
1279
1280- The select module now compiles on platforms that do not define
1281 POLLRDNORM and related constants.
1282
1283- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001284 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001285
Jeremy Hylton10921202000-10-09 18:34:12 +00001286- BeOS: A number of changes were made to the build and installation
1287 process. ar-fake now operates on a directory of object files.
1288 dl_export.h is gone, and its macros now appear on the mwcc command
1289 line during build on PPC BeOS.
1290
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001291- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001292 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001293
1294- Cygwin: Support for shared libraries, Tkinter, and sockets.
1295
1296- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1297
1298Tools and other miscellany
1299
1300- Removed debugging prints from main used with freeze.
1301
Tim Peters46446d62000-10-09 21:19:31 +00001302- IDLE auto-indent no longer crashes when it encounters Unicode
1303 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001304
1305What's new in 2.0 beta 2 (since beta 1)?
1306========================================
1307
1308Core language, builtins, and interpreter
1309
Tim Peters482c0212000-09-26 06:33:09 +00001310- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001311 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001312
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001313- Add -h and -V command line options to print the usage message and
1314 Python version number and exit immediately.
1315
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001316- eval() and exec accept Unicode objects as code parameters.
1317
1318- getattr() and setattr() now also accept Unicode objects for the
1319 attribute name, which are converted to strings using the default
1320 encoding before lookup.
1321
1322- Multiplication on string and Unicode now does proper bounds
1323 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1324 string is too long."
1325
1326- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001327 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001328
Jeremy Hylton1b618592000-09-26 05:32:36 +00001329
1330Standard library and extensions
1331
Guido van Rossum5b08f132001-04-16 02:05:23 +00001332- socket module: the OpenSSL code now adds support for RAND_status()
1333 and EGD (Entropy Gathering Device).
1334
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001335- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001336 argument checking; it still takes no arguments.
1337
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001338- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001339
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001340- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001341
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001342- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001343
1344- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001345 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001346
1347- copy: Copy Unicode objects atomically.
1348
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001349- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001350
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001351- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001352
Fred Drake67233bc2000-09-26 16:40:27 +00001353- dbm: Add get() and setdefault() methods to dbm object. Add constant
1354 `library' to module that names the library used. Added doc strings
1355 and method names to error messages. Uses configure to determine
1356 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1357 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001358
1359- distutils: Update to version 0.9.3.
1360
1361- dl: Add several dl.RTLD_ constants.
1362
1363- fpectl: Now supported on FreeBSD.
1364
1365- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1366 found by the collector will be saved in gc.garbage. This is useful
1367 for debugging a program that creates reference cycles.
1368
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001369- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001370 of HTTP class. Do not close socket on zero-length response. Do not
1371 crash when server sends invalid content-length header.
1372
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001373- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001374
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001375- marshal: When reading a short, sign-extend on platforms where shorts
1376 are bigger than 16 bits. When reading a long, repair the unportable
1377 sign extension that was being done for 64-bit machines. (It assumed
1378 that signed right shift sign-extends.)
1379
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001380- operator: Add contains(), invert(), __invert__() as aliases for
1381 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001382
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001383- os: Add support for popen2() and popen3() on all platforms where
1384 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001385
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001386- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001387 clicking on a file in Explorer (or passing the file name to the
1388 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001389
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001390- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001391 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001392
1393- pickle: Now raises ValueError when an invalid pickle that contains
1394 a non-string repr where a string repr was expected. This behavior
1395 matches cPickle.
1396
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001397- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001398
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001399- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001400
1401- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001402 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001403 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001404
1405- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001406 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001407
1408- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001409 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001410 few cycles during startup since the first call to
1411 setdefaultencoding() will initialize the codec registry and the
1412 encodings package.
1413
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001414- socket: Support for size hint in readlines() method of object returned
1415 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001416
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001417- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001418 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001419 is followed by whitespace.
1420
Tim Petersa3a3a032000-11-30 05:22:44 +00001421- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001422
1423- struct: Check ranges for bytes and shorts.
1424
1425- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001426 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001427
1428- Tkinter: Image objects are now guaranteed to have unique ids. Set
1429 event.delta to zero if Tk version doesn't support mousewheel.
1430 Removed some debugging prints.
1431
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001432- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001433
Fred Drake67233bc2000-09-26 16:40:27 +00001434- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001435 which works around a bug in Norton AntiVirus 2000 that leads directly
1436 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001437
1438- xml: New version detection code allows PyXML to override standard
1439 XML package if PyXML version is greater than 0.6.1.
1440
Fred Drake64bb3802000-09-26 16:21:35 +00001441- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1442 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1443 tree only for nodes which are sufficiently interesting to a specific
1444 application. Does not provide the HTML-specific extensions. Still
1445 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001446
Fred Drake64bb3802000-09-26 16:21:35 +00001447- xml.sax: SAX 2 support for Python, including all the handler
1448 interfaces needed to process XML 1.0 compliant XML. Some
1449 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001450
Fred Drake64bb3802000-09-26 16:21:35 +00001451- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1452 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001453
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001454
Jeremy Hylton1b618592000-09-26 05:32:36 +00001455C API
1456
1457- Add three new convenience functions for module initialization --
1458 PyModule_AddObject(), PyModule_AddIntConstant(), and
1459 PyModule_AddStringConstant().
1460
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001461- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001462 removed and add #error to Python.h if NULL isn't defined after
1463 #include of stdio.h.
1464
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001465- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001466 backwards compatibility (at the source level) with old extensions.
1467
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001468- A wrapper API was added for signal() and sigaction(). Instead of
1469 either function, always use PyOS_getsig() to get a signal handler
1470 and PyOS_setsig() to set one. A new convenience typedef
1471 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001472
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001473- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001474 internal data buffer and size of a string object -- or the default
1475 encoded version of a Unicode object.
1476
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001477- PyString_Size() and PyString_AsString() accept Unicode objects.
1478
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001479- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001480 exists). INT_MAX and LONG_MAX will always be defined, even if
1481 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001482
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001483- PyFloat_FromString takes a second argument, pend, that was
1484 effectively useless. It is now officially useless but preserved for
1485 backwards compatibility. If the pend argument is not NULL, *pend is
1486 set to NULL.
1487
1488- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1489 for the attribute name. See note on getattr() above.
1490
1491- A few bug fixes to argument processing for Unicode.
1492 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1493 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1494 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001495 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001496
1497- Py_BuildValue accepts B format (for bgen-generated code).
1498
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001499
Jeremy Hylton1b618592000-09-26 05:32:36 +00001500Internals
1501
1502- On Unix, fix code for finding Python installation directory so that
1503 it works when argv[0] is a relative path.
1504
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001505- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001506 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001507 rather than by generating a copy of the object.
1508
Tim Peters482c0212000-09-26 06:33:09 +00001509- Several of the internal Unicode tables are much smaller now, and
1510 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001511
Jeremy Hylton97693b02000-09-26 17:42:51 +00001512- In the garbage collector: Fixed bug in collection of tuples. Fixed
1513 bug that caused some instances to be removed from the container set
1514 while they were still live. Fixed parsing in gc.set_debug() for
1515 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001516
1517- Fixed refcount problem in instance deallocation that only occurred
1518 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1519
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001520- On Windows, getpythonregpath is now protected against null data in
1521 registry key.
1522
1523- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001524 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001525
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001526
Jeremy Hylton1b618592000-09-26 05:32:36 +00001527Build and platform-specific issues
1528
1529- Better support of GNU Pth via --with-pth configure option.
1530
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001531- Python/C API now properly exposed to dynamically-loaded extension
1532 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001533
1534- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1535 Don't define MS_SYNC to be zero when it is undefined. Added missing
1536 prototypes in posixmodule.c.
1537
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001538- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001539 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001540
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001541- Fix largefile support on older NetBSD systems and OpenBSD by adding
1542 define for TELL64.
1543
1544
1545Tools and other miscellany
1546
1547- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1548
1549- freeze: The modulefinder now works with 2.0 opcodes.
1550
Tim Petersa3a3a032000-11-30 05:22:44 +00001551- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001552 Move hackery of sys.argv until after the Tk instance has been
1553 created, which allows the application-specific Tkinter
1554 initialization to be executed if present; also pass an explicit
1555 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001556
Jeremy Hylton1b618592000-09-26 05:32:36 +00001557
1558What's new in 2.0 beta 1?
1559=========================
1560
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001561Source Incompatibilities
1562------------------------
1563
1564None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1565such as single-argument append(), connect() and bind(), and changes to
1566str(long) and repr(float).
1567
1568
1569Binary Incompatibilities
1570------------------------
1571
1572- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1573with Python 2.0; these extensions will have to be rebuilt for Python
15742.0.
1575
1576- On Windows, attempting to import a third party extension built for
1577Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1578can do about this. Check your PYTHONPATH environment variable!
1579
1580- Python bytecode files (*.pyc and *.pyo) are not compatible between
1581releases.
1582
1583
1584Overview of Changes Since 1.6
1585-----------------------------
1586
1587There are many new modules (including brand new XML support through
1588the xml package, and i18n support through the gettext module); a list
1589of all new modules is included below. Lots of bugs have been fixed.
1590
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001591The process for making major new changes to the language has changed
1592since Python 1.6. Enhancements must now be documented by a Python
1593Enhancement Proposal (PEP) before they can be accepted.
1594
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001595There are several important syntax enhancements, described in more
1596detail below:
1597
1598 - Augmented assignment, e.g. x += 1
1599
1600 - List comprehensions, e.g. [x**2 for x in range(10)]
1601
1602 - Extended import statement, e.g. import Module as Name
1603
1604 - Extended print statement, e.g. print >> file, "Hello"
1605
1606Other important changes:
1607
1608 - Optional collection of cyclical garbage
1609
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001610Python Enhancement Proposal (PEP)
1611---------------------------------
1612
1613PEP stands for Python Enhancement Proposal. A PEP is a design
1614document providing information to the Python community, or describing
1615a new feature for Python. The PEP should provide a concise technical
1616specification of the feature and a rationale for the feature.
1617
1618We intend PEPs to be the primary mechanisms for proposing new
1619features, for collecting community input on an issue, and for
1620documenting the design decisions that have gone into Python. The PEP
1621author is responsible for building consensus within the community and
1622documenting dissenting opinions.
1623
1624The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001625
1626Augmented Assignment
1627--------------------
1628
1629This must have been the most-requested feature of the past years!
1630Eleven new assignment operators were added:
1631
Guido van Rossume905e952000-09-05 12:42:46 +00001632 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001633
1634For example,
1635
1636 A += B
1637
1638is similar to
1639
1640 A = A + B
1641
1642except that A is evaluated only once (relevant when A is something
1643like dict[index].attr).
1644
1645However, if A is a mutable object, A may be modified in place. Thus,
1646if A is a number or a string, A += B has the same effect as A = A+B
1647(except A is only evaluated once); but if a is a list, A += B has the
1648same effect as A.extend(B)!
1649
1650Classes and built-in object types can override the new operators in
1651order to implement the in-place behavior; the not-in-place behavior is
1652used automatically as a fallback when an object doesn't implement the
1653in-place behavior. For classes, the method name is derived from the
1654method name for the corresponding not-in-place operator by inserting
1655an 'i' in front of the name, e.g. __iadd__ implements in-place
1656__add__.
1657
1658Augmented assignment was implemented by Thomas Wouters.
1659
1660
1661List Comprehensions
1662-------------------
1663
1664This is a flexible new notation for lists whose elements are computed
1665from another list (or lists). The simplest form is:
1666
1667 [<expression> for <variable> in <sequence>]
1668
Guido van Rossum56db0952000-09-06 23:34:25 +00001669For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001670This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001671
1672You can also add a condition:
1673
1674 [<expression> for <variable> in <sequence> if <condition>]
1675
1676For example, [w for w in words if w == w.lower()] would yield the list
1677of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001678than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001679
1680You can also have nested for loops and more than one 'if' clause. For
1681example, here's a function that flattens a sequence of sequences::
1682
1683 def flatten(seq):
1684 return [x for subseq in seq for x in subseq]
1685
1686 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1687
1688This prints
1689
1690 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1691
1692List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001693Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001694
1695
1696Extended Import Statement
1697-------------------------
1698
1699Many people have asked for a way to import a module under a different
1700name. This can be accomplished like this:
1701
1702 import foo
1703 bar = foo
1704 del foo
1705
1706but this common idiom gets old quickly. A simple extension of the
1707import statement now allows this to be written as follows:
1708
1709 import foo as bar
1710
1711There's also a variant for 'from ... import':
1712
1713 from foo import bar as spam
1714
1715This also works with packages; e.g. you can write this:
1716
1717 import test.regrtest as regrtest
1718
1719Note that 'as' is not a new keyword -- it is recognized only in this
1720context (this is only possible because the syntax for the import
1721statement doesn't involve expressions).
1722
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001723Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001724
1725
1726Extended Print Statement
1727------------------------
1728
1729Easily the most controversial new feature, this extension to the print
1730statement adds an option to make the output go to a different file
1731than the default sys.stdout.
1732
1733For example, to write an error message to sys.stderr, you can now
1734write:
1735
1736 print >> sys.stderr, "Error: bad dog!"
1737
1738As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001739evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001740
1741 print >> None, "Hello world"
1742
1743is equivalent to
1744
1745 print "Hello world"
1746
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001747Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001748
1749
1750Optional Collection of Cyclical Garbage
1751---------------------------------------
1752
1753Python is now equipped with a garbage collector that can hunt down
1754cyclical references between Python objects. It's no replacement for
1755reference counting; in fact, it depends on the reference counts being
1756correct, and decides that a set of objects belong to a cycle if all
1757their reference counts can be accounted for from their references to
1758each other. This devious scheme was first proposed by Eric Tiedemann,
1759and brought to implementation by Neil Schemenauer.
1760
1761There's a module "gc" that lets you control some parameters of the
1762garbage collection. There's also an option to the configure script
1763that lets you enable or disable the garbage collection. In 2.0b1,
1764it's on by default, so that we (hopefully) can collect decent user
1765experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001766performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001767off by default in the final 2.0 release.
1768
1769
1770Smaller Changes
1771---------------
1772
1773A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1774map(None, seq1, seq2, ...) when the sequences have the same length;
1775i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1776the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001777zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001778
1779sys.version_info is a tuple (major, minor, micro, level, serial).
1780
1781Dictionaries have an odd new method, setdefault(key, default).
1782dict.setdefault(key, default) returns dict[key] if it exists; if not,
1783it sets dict[key] to default and returns that value. Thus:
1784
1785 dict.setdefault(key, []).append(item)
1786
1787does the same work as this common idiom:
1788
1789 if not dict.has_key(key):
1790 dict[key] = []
1791 dict[key].append(item)
1792
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001793There are two new variants of SyntaxError that are raised for
1794indentation-related errors: IndentationError and TabError.
1795
1796Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1797escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001798
1799The limits on the size of expressions and file in Python source code
1800have been raised from 2**16 to 2**32. Previous versions of Python
1801were limited because the maximum argument size the Python VM accepted
1802was 2**16. This limited the size of object constructor expressions,
1803e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1804limit was raised thanks to a patch by Charles Waldman that effectively
1805fixes the problem. It is now much more likely that you will be
1806limited by available memory than by an arbitrary limit in Python.
1807
1808The interpreter's maximum recursion depth can be modified by Python
1809programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1810limit is the maximum number of recursive calls that can be made by
1811Python code. The limit exists to prevent infinite recursion from
1812overflowing the C stack and causing a core dump. The default value is
18131000. The maximum safe value for a particular platform can be found
1814by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001815
1816New Modules and Packages
1817------------------------
1818
1819atexit - for registering functions to be called when Python exits.
1820
1821imputil - Greg Stein's alternative API for writing custom import
1822hooks.
1823
1824pyexpat - an interface to the Expat XML parser, contributed by Paul
1825Prescod.
1826
1827xml - a new package with XML support code organized (so far) in three
1828subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1829would fill a volume. There's a special feature whereby a
1830user-installed package named _xmlplus overrides the standard
1831xmlpackage; this is intended to give the XML SIG a hook to distribute
1832backwards-compatible updates to the standard xml package.
1833
1834webbrowser - a platform-independent API to launch a web browser.
1835
1836
Guido van Rossume905e952000-09-05 12:42:46 +00001837Changed Modules
1838---------------
1839
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001840array -- new methods for array objects: count, extend, index, pop, and
1841remove
1842
1843binascii -- new functions b2a_hex and a2b_hex that convert between
1844binary data and its hex representation
1845
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001846calendar -- Many new functions that support features including control
1847over which day of the week is the first day, returning strings instead
1848of printing them. Also new symbolic constants for days of week,
1849e.g. MONDAY, ..., SUNDAY.
1850
1851cgi -- FieldStorage objects have a getvalue method that works like a
1852dictionary's get method and returns the value attribute of the object.
1853
1854ConfigParser -- The parser object has new methods has_option,
1855remove_section, remove_option, set, and write. They allow the module
1856to be used for writing config files as well as reading them.
1857
1858ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001859optionally support the RFC 959 REST command.
1860
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001861gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001862
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001863httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1864the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001865
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001866locale -- implement getdefaultlocale for Win32 and Macintosh
1867
1868marshal -- no longer dumps core when marshaling deeply nested or
1869recursive data structures
1870
1871os -- new functions isatty, seteuid, setegid, setreuid, setregid
1872
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001873os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1874support under Unix.
1875
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001876os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001877
1878os.path -- fix semantics of os.path.commonprefix
1879
1880smtplib -- support for sending very long messages
1881
1882socket -- new function getfqdn()
1883
1884readline -- new functions to read, write and truncate history files.
1885The readline section of the library reference manual contains an
1886example.
1887
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001888select -- add interface to poll system call
1889
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001890shutil -- new copyfileobj function
1891
1892SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1893HTTP server.
1894
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001895Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001896
1897urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001898e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001899
1900whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001901
1902
1903Obsolete Modules
1904----------------
1905
1906None. However note that 1.6 made a whole slew of modules obsolete:
1907stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1908poly, zmod, strop, util, whatsound.
1909
1910
1911Changed, New, Obsolete Tools
1912----------------------------
1913
Tim Peters8b092332000-09-05 20:15:25 +00001914None.
Guido van Rossume905e952000-09-05 12:42:46 +00001915
1916
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001917C-level Changes
1918---------------
1919
1920Several cleanup jobs were carried out throughout the source code.
1921
1922All C code was converted to ANSI C; we got rid of all uses of the
1923Py_PROTO() macro, which makes the header files a lot more readable.
1924
1925Most of the portability hacks were moved to a new header file,
1926pyport.h; several other new header files were added and some old
1927header files were removed, in an attempt to create a more rational set
1928of header files. (Few of these ever need to be included explicitly;
1929they are all included by Python.h.)
1930
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001931Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001932and Win64, especially for the new Intel Itanium processor. Mick also
1933added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001934
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001935The C APIs to return an object's size have been update to consistently
1936use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1937previous versions, the abstract interfaces used PyXXX_Length and the
1938concrete interfaces used PyXXX_Size. The old names,
1939e.g. PyObject_Length, are still available for backwards compatibility
1940at the API level, but are deprecated.
1941
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001942The PyOS_CheckStack function has been implemented on Windows by
1943Fredrik Lundh. It prevents Python from failing with a stack overflow
1944on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001945
1946The GC changes resulted in creation of two new slots on object,
1947tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001948the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001949
1950The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001951C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001952
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001953PyErr_Format has been updated to automatically calculate the size of
1954the buffer needed to hold the formatted result string. This change
1955prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001956
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001957New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001958
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001959PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1960that are the same as their non-Ex counterparts except they take an
1961extra flag argument that tells them to close the file when done.
1962
1963XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001964
Tim Peters8b092332000-09-05 20:15:25 +00001965
1966Windows Changes
1967---------------
1968
1969New popen2/popen3/peopen4 in os module (see Changed Modules above).
1970
1971os.popen is much more usable on Windows 95 and 98. See Microsoft
1972Knowledge Base article Q150956. The Win9x workaround described there
1973is implemented by the new w9xpopen.exe helper in the root of your
1974Python installation. Note that Python uses this internally; it is not
1975a standalone program.
1976
1977Administrator privileges are no longer required to install Python
1978on Windows NT or Windows 2000. If you have administrator privileges,
1979Python's registry info will be written under HKEY_LOCAL_MACHINE.
1980Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001981under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001982uses of Python, but will prevent some advanced uses from working
1983(for example, running a Python script as an NT service, or possibly
1984from CGI).
1985
1986[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1987installer; instead, it installs the needed Tcl/Tk files directly in the
1988Python directory. If you already have a Tcl/Tk installation, this
1989wastes some disk space (about 4 Megs) but avoids problems with
1990conflicting Tcl/Tk installations, and makes it much easier for Python
1991to ensure that Tcl/Tk can find all its files.
1992
1993[This was new in 1.6] The Windows installer now installs by default in
1994\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1995
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001996
1997Updates to the changes between 1.5.2 and 1.6
1998--------------------------------------------
1999
2000The 1.6 NEWS file can't be changed after the release is done, so here
2001is some late-breaking news:
2002
2003New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2004and changes to getlocale() and setlocale().
2005
2006The new module is now enabled per default.
2007
2008It is not true that the encodings codecs cannot be used for normal
2009strings: the string.encode() (which is also present on 8-bit strings
2010!) allows using them for 8-bit strings too, e.g. to convert files from
2011cp1252 (Windows) to latin-1 or vice-versa.
2012
2013Japanese codecs are available from Tamito KAJIYAMA:
2014http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2015
2016
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002017======================================================================