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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
32 zlib | string | string | zlib compression
33 hex | string | string | 2-byte hex codec
34 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
35
Mark Hammond2a0af792001-05-14 03:09:36 +000036- Some operating systems now support the concept of a default Unicode
37 encoding for file system operations. Notably, Windows supports 'mbcs'
38 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +000039 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000040 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000041
42 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000043 functions that return filenames (such as os.listdir()) to return Python
44 string objects pre-encoded using the default file system encoding for
45 the platform. As this encoding is likely to be different from Python's
46 default encoding, converting this name to a Unicode object before passing
47 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000048 would attempt to use its default encoding (generally ASCII) rather than
49 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000050
Tim Petersa814db52001-05-14 07:05:58 +000051 In general, this change simply removes surprises when working with
52 Unicode and the file system, making these operations work as you expect,
53 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +000054 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +000055
Tim Peters61dff2b2001-05-08 15:43:37 +000056- Float (and complex) literals in source code were evaluated to full
57 precision only when running from a .py file; the same code loaded from a
58 .pyc (or .pyo) file could suffer numeric differences starting at about the
59 12th significant decimal digit. For example, on a machine with IEEE-754
60 floating arithmetic,
61
62 x = 9007199254740992.0
63 print long(x)
64
65 printed 9007199254740992 if run directly from .py, but 9007199254740000
66 if from a compiled (.pyc or .pyo) file. This was due to marshal using
67 str(float) instead of repr(float) when building code objects. marshal
68 now uses repr(float) instead, which should reproduce floats to full
69 machine precision (assuming the platform C float<->string I/O conversion
70 functions are of good quality).
71
72 This may cause floating-point results to change in some cases, and
73 usually for the better, but may also cause numerically unstable
74 algorithms to break.
75
Tim Peters2f228e72001-05-13 00:19:31 +000076- The implementation of dicts suffers fewer collisions, which has speed
77 benefits. However, the order in which dict entries appear in dict.keys(),
78 dict.values() and dict.items() may differ from previous releases for a
79 given dict. Nothing is defined about this order, so no program should
80 rely on it. Nevertheless, it's easy to write test cases that rely on the
81 order by accident, typically because of printing the str() or repr() of a
82 dict to an "expected results" file. See Lib/test/test_support.py's new
83 sortdict(dict) function for a simple way to display a dict in sorted
84 order.
85
Guido van Rossum10315822001-05-01 20:54:30 +000086- Dictionary objects now support the "in" operator: "x in dict" means
87 the same as dict.has_key(x).
88
89- Iterators were added; this is a generalized way of providing values
90 to a for loop. See PEP 234. There's a new built-in function iter()
91 to return an iterator. There's a new protocol to get the next value
92 from an iterator using the next() method (in Python) or the
93 tp_iternext slot (in C). There's a new protocol to get iterators
94 using the __iter__() method (in Python) or the tp_iter slot (in C).
95 Iterating (i.e. a for loop) over a dictionary generates its keys.
96 Iterating over a file generates its lines.
97
Tim Petersf553f892001-05-01 20:45:31 +000098- The following functions were generalized to work nicely with iterator
99 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000100 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000101 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
102 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000103 join() method of strings
104 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000105 'x in y' and 'x not in y' (PySequence_Contains() in C API)
106 operator.countOf() (PySequence_Count() in C API)
Tim Peters75f8e352001-05-05 11:33:43 +0000107
Tim Petersd85e1022001-05-11 21:51:48 +0000108- Accessing module attributes is significantly faster (for example,
109 random.random or os.path or yourPythonModule.yourAttribute).
110
Tim Peterse63415e2001-05-08 04:38:29 +0000111- Comparing dictionary objects via == and != is faster, and now works even
112 if the keys and values don't support comparisons other than ==.
113
Tim Peters95bf9392001-05-10 08:32:44 +0000114- Comparing dictionaries in ways other than == and != is slower: there were
115 insecurities in the dict comparison implementation that could cause Python
116 to crash if the element comparison routines for the dict keys and/or
117 values mutated the dicts. Making the code bulletproof slowed it down.
118
Tim Peterseb28ef22001-06-02 05:27:19 +0000119- Collisions in dicts are resolved via a new approach, which can help
120 dramatically in bad cases. For example, looking up every key in a dict
121 d with d.keys() = [i << 16 for i in range(20000)] is approximately 500x
122 faster now. Thanks to Christian Tismer for pointing out the cause and
123 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000124
Tim Petersa814db52001-05-14 07:05:58 +0000125Library
126
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000127- A new function fnmatch.filter to filter lists of file names was added.
128
Barry Warsawffd674d2001-05-22 16:00:10 +0000129- calendar.py uses month and day names based on the current locale.
130
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000131- strop is now *really* obsolete (this was announced before with 1.6),
132 and issues DeprecationWarning when used (except for the four items
133 that are still imported into string.py).
134
Tim Petersa814db52001-05-14 07:05:58 +0000135- Cookie.py now sorts key+value pairs by key in output strings.
136
137- pprint.isrecursive(object) didn't correctly identify recursive objects.
138 Now it does.
139
Tim Peters95b3f782001-05-14 18:39:41 +0000140- pprint functions now much faster for large containers (tuple, list, dict).
141
Tim Petersa814db52001-05-14 07:05:58 +0000142Tests
143
144- New test_mutants.py runs dict comparisons where the key and value
145 comparison operators mutute the dicts randomly during comparison. This
146 rapidly causes Python to crash under earlier releases (not for the faint
147 of heart: it can also cause Win9x to freeze or reboot!).
148
149- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000150 pprint.isreadable() return sensible results. Also verifies that simple
151 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000152
Tim Peters58e0a8c2001-05-14 22:32:33 +0000153New platforms
154
155- Python should compile and run out of the box using the Borland C
156 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000157
Tim Peters4324aa32001-05-28 22:30:08 +0000158C API
159
160- Removed the unused last_is_sticky argument from the internal
161 _PyTuple_Resize(). If this affects you, you were cheating.
162
163
Guido van Rossumffe13be2001-04-16 18:46:45 +0000164What's New in Python 2.1 (final)?
165=================================
166
167We only changed a few things since the last release candidate, all in
168Python library code:
169
170- A bug in the locale module was fixed that affected locales which
171 define no grouping for numeric formatting.
172
173- A few bugs in the weakref module's implementations of weak
174 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
175 and the test suite was updated to check for these bugs.
176
177- An old bug in the os.path.walk() function (introduced in Python
178 2.0!) was fixed: a non-existent file would cause an exception
179 instead of being ignored.
180
181- Fixed a few bugs in the new symtable module found by Neil Norwitz's
182 PyChecker.
183
184
Guido van Rossum5b08f132001-04-16 02:05:23 +0000185What's New in Python 2.1c2?
186===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000187
Guido van Rossum5b08f132001-04-16 02:05:23 +0000188A flurry of small changes, and one showstopper fixed in the nick of
189time made it necessary to release another release candidate. The list
190here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000191
Guido van Rossum5b08f132001-04-16 02:05:23 +0000192Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000193
Guido van Rossum5b08f132001-04-16 02:05:23 +0000194- Tim discovered a nasty bug in the dictionary code, caused by
195 PyDict_Next() calling dict_resize(), and the GC code's use of
196 PyDict_Next() violating an assumption in dict_items(). This was
197 fixed with considerable amounts of band-aid, but the net effect is a
198 saner and more robust implementation.
199
200- Made a bunch of symbols static that were accidentally global.
201
202Build and Ports
203
204- The setup.py script didn't check for a new enough version of zlib
205 (1.1.3 is needed). Now it does.
206
207- Changed "make clean" target to also remove shared libraries.
208
209- Added a more general warning about the SGI Irix optimizer to README.
210
211Library
212
213- Fix a bug in urllib.basejoin("http://host", "../file.html") which
214 omitted the slash between host and file.html.
215
216- The mailbox module's _Mailbox class contained a completely broken
217 and undocumented seek() method. Ripped it out.
218
219- Fixed a bunch of typos in various library modules (urllib2, smtpd,
220 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
221
222- Fixed a few last-minute bugs in unittest.
223
224Extensions
225
226- Reverted the patch to the OpenSSL code in socketmodule.c to support
227 RAND_status() and the EGD, and the subsequent patch that tried to
228 fix it for pre-0.9.5 versions; the problem with the patch is that on
229 some systems it issues a warning whenever socket is imported, and
230 that's unacceptable.
231
232Tests
233
234- Fixed the pickle tests to work with "import test.test_pickle".
235
236- Tweaked test_locale.py to actually run the test Windows.
237
238- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
239 not "wb" (which is not a valid mode at all).
240
241- Fix pstats browser crashes. Import readline if it exists to make
242 the user interface nicer.
243
244- Add "import thread" to the top of test modules that import the
245 threading module (test_asynchat and test_threadedtempfile). This
246 prevents test failures caused by a broken threading module resulting
247 from a previously caught failed import.
248
249- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
250 needed on some platforms (e.g. Solaris 8) when the tests are run
251 twice in succession.
252
253- Skip rather than fail test_sunaudiodev if no audio device is found.
254
255
256What's New in Python 2.1c1?
257===========================
258
259This list was significantly updated when 2.1c2 was released; the 2.1c1
260release didn't mention most changes that were actually part of 2.1c1:
261
262Legal
263
264- Copyright was assigned to the Python Software Foundation (PSF) and a
265 PSF license (very similar to the CNRI license) was added.
266
267- The CNRI copyright notice was updated to include 2001.
268
269Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000270
Guido van Rossumc9932722001-04-12 02:31:27 +0000271- After a public outcry, assignment to __debug__ is no longer illegal;
272 instead, a warning is issued. It will become illegal in 2.2.
273
Guido van Rossum5b08f132001-04-16 02:05:23 +0000274- Fixed a core dump with "%#x" % 0, and changed the semantics so that
275 "%#x" now always prepends "0x", even if the value is zero.
276
277- Fixed some nits in the bytecode compiler.
278
279- Fixed core dumps when calling certain kinds of non-functions.
280
281- Fixed various core dumps caused by reference count bugs.
282
283Build and Ports
284
285- Use INSTALL_SCRIPT to install script files.
286
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000287- New port: SCO Unixware 7, by Billy G. Allie.
288
Guido van Rossum5b08f132001-04-16 02:05:23 +0000289- Updated RISCOS port.
290
291- Updated BeOS port and notes.
292
293- Various other porting problems resolved.
294
295Library
296
297- The TERMIOS and SOCKET modules are now truly obsolete and
298 unnecessary. Their symbols are incorporated in the termios and
299 socket modules.
300
301- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
302 better tests for pickling.
303
304- threading: make Condition.wait() robust against KeyboardInterrupt.
305
306- zipfile: add support to zipfile to support opening an archive
307 represented by an open file rather than a file name. Fix bug where
308 the archive was not properly closed. Fixed a bug in this bugfix
309 where flush() was called for a read-only file.
310
311- imputil: added an uninstall() method to the ImportManager.
312
313- Canvas: fixed bugs in lower() and tkraise() methods.
314
315- SocketServer: API change (added overridable close_request() method)
316 so that the TCP server can explicitly close the request.
317
318- pstats: Eric Raymond added a simple interactive statistics browser,
319 invoked when the module is run as a script.
320
321- locale: fixed a problem in format().
322
323- webbrowser: made it work when the BROWSER environment variable has a
324 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
325 KDE 2. Fixed some other nits.
326
327- unittest: changes to allow using a different exception than
328 AssertionError, and added a few more function aliases. Some other
329 small changes.
330
331- urllib, urllib2: fixed redirect problems and a coupleof other nits.
332
333- asynchat: fixed a critical bug in asynchat that slipped through the
334 2.1b2 release. Fixed another rare bug.
335
336- Fix some unqualified except: clauses (always a bad code example).
337
338XML
339
340- pyexpat: new API get_version_string().
341
342- Fixed some minidom bugs.
343
344Extensions
345
346- Fixed a core dump in _weakref. Removed the weakref.mapping()
347 function (it adds nothing to the API).
348
349- Rationalized the use of header files in the readline module, to make
350 it compile (albeit with some warnings) with the very recent readline
351 4.2, without breaking for earlier versions.
352
353- Hopefully fixed a buffering problem in linuxaudiodev.
354
355- Attempted a fix to make the OpenSSL support in the socket module
356 work again with pre-0.9.5 versions of OpenSSL.
357
358Tests
359
360- Added a test case for asynchat and asyncore.
361
362- Removed coupling between tests where one test failing could break
363 another.
364
365Tools
366
367- Ping added an interactive help browser to pydoc, fixed some nits
368 in the rest of the pydoc code, and added some features to his
369 inspect module.
370
371- An updated python-mode.el version 4.1 which integrates Ken
372 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
373 much nicer in XEmacs and Emacs. When stepping through your program
374 with pdb, in either the shell window or the *Python* window, the
375 source file and line will be tracked by an arrow. Very cool!
376
377- IDLE: syntax warnings in interactive mode are changed into errors.
378
379- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000380 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000381
382- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000383
Barry Warsaw11e89c72001-04-11 20:37:57 +0000384
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000385What's New in Python 2.1 beta 2?
386================================
387
Guido van Rossum053ae352001-03-22 14:17:21 +0000388(Unlisted are many fixed bugs, more documentation, etc.)
389
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000390Core language, builtins, and interpreter
391
Guido van Rossum053ae352001-03-22 14:17:21 +0000392- The nested scopes work (enabled by "from __future__ import
393 nested_scopes") is completed; in particular, the future now extends
394 into code executed through exec, eval() and execfile(), and into the
395 interactive interpreter.
396
397- When calling a base class method (e.g. BaseClass.__init__(self)),
398 this is now allowed even if self is not strictly spoken a class
399 instance (e.g. when using metaclasses or the Don Beaudry hook).
400
401- Slice objects are now comparable but not hashable; this prevents
402 dict[:] from being accepted but meaningless.
403
404- Complex division is now calculated using less braindead algorithms.
405 This doesn't change semantics except it's more likely to give useful
406 results in extreme cases. Complex repr() now uses full precision
407 like float repr().
408
409- sgmllib.py now calls handle_decl() for simple <!...> declarations.
410
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000411- It is illegal to assign to the name __debug__, which is set when the
412 interpreter starts. It is effectively a compile-time constant.
413
414- A warning will be issued if a global statement for a variable
415 follows a use or assignment of that variable.
416
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000417Standard library
418
Guido van Rossum053ae352001-03-22 14:17:21 +0000419- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
420 inspired by JUnit), is now part of the standard library. You now
421 have a choice of two testing frameworks: unittest requires you to
422 write testcases as separate code, doctest gathers them from
423 docstrings. Both approaches have their advantages and
424 disadvantages.
425
426- A new module Tix was added, which wraps the Tix extension library
427 for Tk. With that module, it is not necessary to statically link
428 Tix with _tkinter, since Tix will be loaded with Tcl's "package
429 require" command. See Demo/tix/.
430
431- tzparse.py is now obsolete.
432
433- In gzip.py, the seek() and tell() methods are removed -- they were
434 non-functional anyway, and it's better if callers can test for their
435 existence with hasattr().
436
437Python/C API
438
439- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
440 that's already in the dictionary during a PyDict_Next() iteration.
441 This used to fail occasionally when a dictionary resize operation
442 could be triggered that would rehash all the keys. All other
443 modifications to the dictionary are still off-limits during a
444 PyDict_Next() iteration!
445
446- New extended APIs related to passing compiler variables around.
447
448- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
449 implement isinstance() and issubclass().
450
451- Py_BuildValue() now has a "D" conversion to create a Python complex
452 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000453
Fred Drake4e262a92001-03-22 18:26:47 +0000454- Extensions types which support weak references must now set the
455 field allocated for the weak reference machinery to NULL themselves;
456 this is done to avoid the cost of checking each object for having a
457 weakly referencable type in PyObject_INIT(), since most types are
458 not weakly referencable.
459
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000460- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
461 free variables and cell variables to and from the frame's f_locals.
462
463- Variants of several functions defined in pythonrun.h have been added
464 to support the nested_scopes future statement. The variants all end
465 in Flags and take an extra argument, a PyCompilerFlags *; examples:
466 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
467 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000468 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000469
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000470Distutils
471
472- the sdist command now writes a PKG-INFO file, as described in PEP 241,
473 into the release tree.
474
Tim Peters0e57abf2001-05-02 07:39:38 +0000475- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000476 (an uninstaller, more customization of the installer's display)
477
478- from Jack Jansen: added Mac-specific code to generate a dialog for
479 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000480 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000481 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000482
483- added 'platforms' and 'keywords' to the set of metadata that can be
484 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000485
486- applied patches from Jason Tishler to make the compiler class work with
487 Cygwin.
488
489
Tim Peters2fe289a2001-03-01 22:19:38 +0000490What's New in Python 2.1 beta 1?
491================================
Tim Petersd66595f2001-02-04 03:09:53 +0000492
493Core language, builtins, and interpreter
494
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000495- Following an outcry from the community about the amount of code
496 broken by the nested scopes feature introduced in 2.1a2, we decided
497 to make this feature optional, and to wait until Python 2.2 (or at
498 least 6 months) to make it standard. The option can be enabled on a
499 per-module basis by adding "from __future__ import nested_scopes" at
500 the beginning of a module (before any other statements, but after
501 comments and an optional docstring). See PEP 236 (Back to the
502 __future__) for a description of the __future__ statement. PEP 227
503 (Statically Nested Scopes) has been updated to reflect this change,
504 and to clarify the semantics in a number of endcases.
505
506- The nested scopes code, when enabled, has been hardened, and most
507 bugs and memory leaks in it have been fixed.
508
509- Compile-time warnings are now generated for a number of conditions
510 that will break or change in meaning when nested scopes are enabled:
511
512 - Using "from...import *" or "exec" without in-clause in a function
513 scope that also defines a lambda or nested function with one or
514 more free (non-local) variables. The presence of the import* or
515 bare exec makes it impossible for the compiler to determine the
516 exact set of local variables in the outer scope, which makes it
517 impossible to determine the bindings for free variables in the
518 inner scope. To avoid the warning about import *, change it into
519 an import of explicitly name object, or move the import* statement
520 to the global scope; to avoid the warning about bare exec, use
521 exec...in... (a good idea anyway -- there's a possibility that
522 bare exec will be deprecated in the future).
523
524 - Use of a global variable in a nested scope with the same name as a
525 local variable in a surrounding scope. This will change in
526 meaning with nested scopes: the name in the inner scope will
527 reference the variable in the outer scope rather than the global
528 of the same name. To avoid the warning, either rename the outer
529 variable, or use a global statement in the inner function.
530
Neil Schemenauera35c6882001-02-27 04:45:05 +0000531- An optional object allocator has been included. This allocator is
532 optimized for Python objects and should be faster and use less memory
533 than the standard system allocator. It is not enabled by default
534 because of possible thread safety problems. The allocator is only
535 protected by the Python interpreter lock and it is possible that some
536 extension modules require a thread safe allocator. The object
537 allocator can be enabled by providing the "--with-pymalloc" option to
538 configure.
539
Tim Petersd66595f2001-02-04 03:09:53 +0000540Standard library
541
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000542- pyexpat now detects the expat version if expat.h defines it. A
543 number of additional handlers are provided, which are only available
544 since expat 1.95. In addition, the methods SetParamEntityParsing and
545 GetInputContext of Parser objects are available with 1.95.x
546 only. Parser objects now provide the ordered_attributes and
547 specified_attributes attributes. A new module expat.model was added,
548 which offers a number of additional constants if 1.95.x is used.
549
550- xml.dom offers the new functions registerDOMImplementation and
551 getDOMImplementation.
552
553- xml.dom.minidom offers a toprettyxml method. A number of DOM
554 conformance issues have been resolved. In particular, Element now
555 has an hasAttributes method, and the handling of namespaces was
556 improved.
557
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000558- Ka-Ping Yee contributed two new modules: inspect.py, a module for
559 getting information about live Python code, and pydoc.py, a module
560 for interactively converting docstrings to HTML or text.
561 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000562 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000563 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
564 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000565
Tim Peters1eff7962001-03-01 02:31:33 +0000566- New library module difflib.py, primarily packaging the SequenceMatcher
567 class at the heart of the popular ndiff.py file-comparison tool.
568
569- doctest.py (a framework for verifying Python code examples in docstrings)
570 is now part of the std library.
571
Tim Petersd66595f2001-02-04 03:09:53 +0000572Windows changes
573
Guido van Rossume3955a82001-03-02 14:05:59 +0000574- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
575 small GUI that lets you browse the module docstrings using your
576 default web browser.
577
Tim Peters1eff7962001-03-01 02:31:33 +0000578- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
579 Platforms) is implemented. See
580
581 http://python.sourceforge.net/peps/pep-0235.html
582
583 for full details, especially the "Current Lower-Left Semantics" section.
584 The new Windows import rules are simpler than before:
585
586 A. If the PYTHONCASEOK environment variable exists, same as
587 before: silently accept the first case-insensitive match of any
588 kind; raise ImportError if none found.
589
590 B. Else search sys.path for the first case-sensitive match; raise
591 ImportError if none found.
592
593 The same rules have been implented on other platforms with case-
594 insensitive but case-preserving filesystems too (including Cygwin, and
595 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000596
Tim Peters25a9ce32001-02-19 07:06:36 +0000597- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
598 what it's supposed to do (and does do under NT and 2000) via direct
599 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000600 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000601 all Win9x systems before.
602
Tim Peters1eff7962001-03-01 02:31:33 +0000603- Build: Subproject _test (effectively) renamed to _testcapi.
604
Tim Peters2fe289a2001-03-01 22:19:38 +0000605New platforms
606
607- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
608 Thanks to Steven Majewski!
609
610- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
611 Tishler!
612
Guido van Rossum9089b272001-03-02 06:49:50 +0000613- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
614 Schwertberger! See RISCOS/README for more information -- it seems
615 that because of the bizarre filename conventions on RISCOS, no port
616 to that platform is easy. Note that the new variable os.endsep is
617 silently supported in order to make life easier on this platform,
618 but we don't advertise it because it's not worth for most folks to
619 care about RISCOS portability.
620
Tim Peters25a9ce32001-02-19 07:06:36 +0000621
Tim Petersd7b5e882001-01-25 03:36:26 +0000622What's New in Python 2.1 alpha 2?
623=================================
Tim Peters40ead762001-01-27 05:35:26 +0000624
Tim Petersd7b5e882001-01-25 03:36:26 +0000625Core language, builtins, and interpreter
626
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000627- Scopes nest. If a name is used in a function or class, but is not
628 local, the definition in the nearest enclosing function scope will
629 be used. One consequence of this change is that lambda statements
630 could reference variables in the namespaces where the lambda is
631 defined. In some unusual cases, this change will break code.
632
633 In all previous version of Python, names were resolved in exactly
634 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000635 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000636 function A is defined within a function B, the names bound in B are
637 not visible in A. The new rules make names bound in B visible in A,
638 unless A contains a name binding that hides the binding in B.
639
640 Section 4.1 of the reference manual describes the new scoping rules
641 in detail. The test script in Lib/test/test_scope.py demonstrates
642 some of the effects of the change.
643
644 The new rules will cause existing code to break if it defines nested
645 functions where an outer function has local variables with the same
646 name as globals or builtins used by the inner function. Example:
647
648 def munge(str):
649 def helper(x):
650 return str(x)
651 if type(str) != type(''):
652 str = helper(str)
653 return str.strip()
654
655 Under the old rules, the name str in helper() is bound to the
656 builtin function str(). Under the new rules, it will be bound to
657 the argument named str and an error will occur when helper() is
658 called.
659
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000660- The compiler will report a SyntaxError if "from ... import *" occurs
661 in a function or class scope. The language reference has documented
662 that this case is illegal, but the compiler never checked for it.
663 The recent introduction of nested scope makes the meaning of this
664 form of name binding ambiguous. In a future release, the compiler
665 may allow this form when there is no possibility of ambiguity.
666
Tim Peters40ead762001-01-27 05:35:26 +0000667- repr(string) is easier to read, now using hex escapes instead of octal,
668 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
669
670 >>> "\texample \r\n" + chr(0) + chr(255)
671 '\texample \r\n\x00\xff' # in 2.1
672 '\011example \015\012\000\377' # in 2.0
673
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000674- Functions are now compared and hashed by identity, not by value, since
675 the func_code attribute is writable.
676
Fred Drakefb9d7122001-02-01 20:00:40 +0000677- Weak references (PEP 205) have been added. This involves a few
678 changes in the core, an extension module (_weakref), and a Python
679 module (weakref). The weakref module is the public interface. It
680 includes support for "explicit" weak references, proxy objects, and
681 mappings with weakly held values.
682
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000683- A 'continue' statement can now appear in a try block within the body
684 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000685 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000686
Tim Petersd7b5e882001-01-25 03:36:26 +0000687Standard library
688
Barry Warsaw30dbd142001-01-31 22:14:01 +0000689- mailbox.py now has a new class, PortableUnixMailbox which is
690 identical to UnixMailbox but uses a more portable scheme for
691 determining From_ separators. Also, the constructors for all the
692 classes in this module have a new optional `factory' argument, which
693 is a callable used when new message classes must be instantiated by
694 the next() method.
695
Tim Petersd7b5e882001-01-25 03:36:26 +0000696- random.py is now self-contained, and offers all the functionality of
697 the now-deprecated whrandom.py. See the docs for details. random.py
698 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000699 and restoring the internal state of the generator; and jumpahead(n),
700 for quickly forcing the internal state to be the same as if n calls to
701 random() had been made. The latter is particularly useful for multi-
702 threaded programs, creating one instance of the random.Random() class for
703 each thread, then using .jumpahead() to force each instance to use a
704 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000705
Tim Peters0de88fc2001-02-01 04:59:18 +0000706- random.py's seed() function is new. For bit-for-bit compatibility with
707 prior releases, use the whseed function instead. The new seed function
708 addresses two problems: (1) The old function couldn't produce more than
709 about 2**24 distinct internal states; the new one about 2**45 (the best
710 that can be done in the Wichmann-Hill generator). (2) The old function
711 sometimes produced identical internal states when passed distinct
712 integers, and there was no simple way to predict when that would happen;
713 the new one guarantees to produce distinct internal states for all
714 arguments in [0, 27814431486576L).
715
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000716- The socket module now supports raw packets on Linux. The socket
717 family is AF_PACKET.
718
Tim Peters9ea17ac2001-02-02 05:57:15 +0000719- test_capi.py is a start at running tests of the Python C API. The tests
720 are implemented by the new Modules/_testmodule.c.
721
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000722- A new extension module, _symtable, provides provisional access to the
723 internal symbol table used by the Python compiler. A higher-level
724 interface will be added on top of _symtable in a future release.
725
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000726- Removed the obsolete soundex module.
727
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000728- xml.dom.minidom now uses the standard DOM exceptions. Node supports
729 the isSameNode method; NamedNodeMap the get method.
730
731- xml.sax.expatreader supports the lexical handler property; it
732 generates comment, startCDATA, and endCDATA events.
733
Tim Petersee826f82001-01-31 19:39:44 +0000734Windows changes
735
736- Build procedure: the zlib project is built in a different way that
737 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000738 the zlib binary used. See PCbuild\readme.txt for details. Your old
739 zlib-related directories can be deleted; you'll need to download fresh
740 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000741
Tim Peters9ea17ac2001-02-02 05:57:15 +0000742- Build: New subproject _test for the benefit of test_capi.py (see above).
743
Tim Petersb16c56f2001-02-02 21:24:51 +0000744- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
745 interface to some Python compiler internals).
746
747- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000748 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000749
Tim Petersa3a3a032000-11-30 05:22:44 +0000750What's New in Python 2.1 alpha 1?
751=================================
752
753Core language, builtins, and interpreter
754
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000755- There is a new Unicode companion to the PyObject_Str() API
756 called PyObject_Unicode(). It behaves in the same way as the
757 former, but assures that the returned value is an Unicode object
758 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000759
Guido van Rossumf98eda02001-01-17 15:54:45 +0000760- The comparison operators support "rich comparison overloading" (PEP
761 207). C extension types can provide a rich comparison function in
762 the new tp_richcompare slot in the type object. The cmp() function
763 and the C function PyObject_Compare() first try the new rich
764 comparison operators before trying the old 3-way comparison. There
765 is also a new C API PyObject_RichCompare() (which also falls back on
766 the old 3-way comparison, but does not constrain the outcome of the
767 rich comparison to a Boolean result).
768
769 The rich comparison function takes two objects (at least one of
770 which is guaranteed to have the type that provided the function) and
771 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
772 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
773 object, which may be NotImplemented (in which case the tp_compare
774 slot function is used as a fallback, if defined).
775
776 Classes can overload individual comparison operators by defining one
777 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000778 __ge__. There are no explicit "reflected argument" versions of
779 these; instead, __lt__ and __gt__ are each other's reflection,
780 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
781 reflection (similar at the C level). No other implications are
782 made; in particular, Python does not assume that == is the Boolean
783 inverse of !=, or that < is the Boolean inverse of >=. This makes
784 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000785
786 Classes or types that want to implement (in)equality tests but not
787 the ordering operators (i.e. unordered types) should implement ==
788 and !=, and raise an error for the ordering operators.
789
Guido van Rossuma88479f2001-01-18 14:28:08 +0000790 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000791 Boolean; e.g. a matrix type might want to return a matrix of bits
792 for A < B, giving elementwise comparisons. Such types should ensure
793 that any interpretation of their value in a Boolean context raises
794 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
795 at the C level) to always raise an exception.
796
Guido van Rossuma88479f2001-01-18 14:28:08 +0000797- Complex numbers use rich comparisons to define == and != but raise
798 an exception for <, <=, > and >=. Unfortunately, this also means
799 that cmp() of two complex numbers raises an exception when the two
800 numbers differ. Since it is not mathematically meaningful to compare
801 complex numbers except for equality, I hope that this doesn't break
802 too much code.
803
Tim Peters3389f192001-02-18 08:48:49 +0000804- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000805 not defined by the language, other than that it's arbitrary but
806 consistent (see the Reference Manual). An implementation detail changed
807 in 2.1a1 such that None now compares less than any other object. Code
808 relying on this new behavior (like code that relied on the previous
809 behavior) does so at its own risk.
810
Barry Warsaw573b5412001-01-15 20:43:18 +0000811- Functions and methods now support getting and setting arbitrarily
812 named attributes (PEP 232). Functions have a new __dict__
813 (a.k.a. func_dict) which hold the function attributes. Methods get
814 and set attributes on their underlying im_func. It is a TypeError
815 to set an attribute on a bound method.
816
Guido van Rossum051e3352001-01-15 19:11:10 +0000817- The xrange() object implementation has been improved so that
818 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
819 limitation that in this case len(xrange(sys.maxint)) can't be
820 calculated, but the common idiom "for i in xrange(sys.maxint)" will
821 work fine as long as the index i doesn't actually reach 2**31.
822 (Python uses regular ints for sequence and string indices; fixing
823 that is much more work.)
824
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000825- Two changes to from...import:
826
Guido van Rossumba381232001-02-03 15:06:40 +0000827 1) "from M import X" now works even if (after loading module M)
828 sys.modules['M'] is not a real module; it's basically a getattr()
829 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000830
831 2) "from M import *" now looks for M.__all__ to decide which names to
832 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
833 filters out names starting with '_' as before. Whether or not
834 __all__ exists, there's no restriction on the type of M.
835
Guido van Rossumf61f1662001-01-10 20:13:55 +0000836- File objects have a new method, xreadlines(). This is the fastest
837 way to iterate over all lines in a file:
838
839 for line in file.xreadlines():
840 ...do something to line...
841
842 See the xreadlines module (mentioned below) for how to do this for
843 other file-like objects.
844
845- Even if you don't use file.xreadlines(), you may expect a speedup on
846 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000847 quite a bit in platform-specific ways: on systems (like Linux) that
848 support flockfile(), getc_unlocked(), and funlockfile(), those are
849 used by default. On systems (like Windows) without getc_unlocked(),
850 a complicated (but still thread-safe) method using fgets() is used by
851 default.
852
Tim Petersd52269b2001-01-25 06:23:18 +0000853 You can force use of the fgets() method by #define'ing
854 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000855 getc_unlocked()).
856
Tim Petersd52269b2001-01-25 06:23:18 +0000857 You can force fgets() not to be used by #define'ing
858 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000859 test_bufio.py fails -- and let us know if it does!).
860
861- In addition, the fileinput module, while still slower than the other
862 methods on most platforms, has been sped up too, by using
863 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000864
865- Support for run-time warnings has been added, including a new
866 command line option (-W) to specify the disposition of warnings.
867 See the description of the warnings module below.
868
869- Extensive changes have been made to the coercion code. This mostly
870 affects extension modules (which can now implement mixed-type
871 numerical operators without having to use coercion), but
872 occasionally, in boundary cases the coercion semantics have changed
873 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000874 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000875 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000876 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000877
Guido van Rossumf98eda02001-01-17 15:54:45 +0000878- In connection with the coercion changes, a new built-in singleton
879 object, NotImplemented is defined. This can be returned for
880 operations that wish to indicate they are not implemented for a
881 particular combination of arguments. From C, this is
882 Py_NotImplemented.
883
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000884- The interpreter accepts now bytecode files on the command line even
885 if they do not have a .pyc or .pyo extension. On Linux, after executing
886
Martin v. Löwise214baa2001-02-04 22:37:56 +0000887import imp,sys,string
888magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
889reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
890open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000891
892 any byte code file can be used as an executable (i.e. as an argument
893 to execve(2)).
894
Tim Peters9940b802000-12-01 07:59:35 +0000895- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000896 character. In 1.6 and earlier, they never produced a sign,
897 and raised an error if the value of the long was too large
898 to fit in a Python int. In 2.0, they produced a sign if and
899 only if too large to fit in an int. This was inconsistent
900 across platforms (because the size of an int varies across
901 platforms), and inconsistent with hex() and oct(). Example:
902
903 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000904 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000905 'ffffffbe' # in 2.0 and before, on 32-bit machines
906 >>> hex(-0x42L)
907 '-0x42L' # in all versions of Python
908
Tim Peters9940b802000-12-01 07:59:35 +0000909 The behavior of %d formats for negative Python longs remains
910 the same as in 2.0 (although in 1.6 and before, they raised
911 an error if the long didn't fit in a Python int).
912
913 %u formats don't make sense for Python longs, but are allowed
914 and treated the same as %d in 2.1. In 2.0, a negative long
915 formatted via %u produced a sign if and only if too large to
916 fit in an int. In 1.6 and earlier, a negative long formatted
917 via %u raised an error if it was too big to fit in an int.
918
Guido van Rossum3661d392000-12-12 22:10:31 +0000919- Dictionary objects have an odd new method, popitem(). This removes
920 an arbitrary item from the dictionary and returns it (in the form of
921 a (key, value) pair). This can be useful for algorithms that use a
922 dictionary as a bag of "to do" items and repeatedly need to pick one
923 item. Such algorithms normally end up running in quadratic time;
924 using popitem() they can usually be made to run in linear time.
925
Tim Peters36cdad12000-12-29 02:06:45 +0000926Standard library
927
Thomas Woutersfe385252001-01-19 23:16:56 +0000928- In the time module, the time argument to the functions strftime,
929 localtime, gmtime, asctime and ctime is now optional, defaulting to
930 the current time (in the local timezone).
931
Guido van Rossumda91f222001-01-15 16:36:08 +0000932- The ftplib module now defaults to passive mode, which is deemed a
933 more useful default given that clients are often inside firewalls
934 these days. Note that this could break if ftplib is used to connect
935 to a *server* that is inside a firewall, from outside; this is
936 expected to be a very rare situation. To fix that, you can call
937 ftp.set_pasv(0).
938
Martin v. Löwis10a27872001-01-13 09:54:41 +0000939- The module site now treats .pth files not only for path configuration,
940 but also supports extensions to the initialization code: Lines starting
941 with import are executed.
942
Guido van Rossumf61f1662001-01-10 20:13:55 +0000943- There's a new module, warnings, which implements a mechanism for
944 issuing and filtering warnings. There are some new built-in
945 exceptions that serve as warning categories, and a new command line
946 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
947 turns warnings into errors). warnings.warn(message[, category])
948 issues a warning message; this can also be called from C as
949 PyErr_Warn(category, message).
950
951- A new module xreadlines was added. This exports a single factory
952 function, xreadlines(). The intention is that this code is the
953 absolutely fastest way to iterate over all lines in an open
954 file(-like) object:
955
956 import xreadlines
957 for line in xreadlines.xreadlines(file):
958 ...do something to line...
959
960 This is equivalent to the previous the speed record holder using
961 file.readlines(sizehint). Note that if file is a real file object
962 (as opposed to a file-like object), this is equivalent:
963
964 for line in file.xreadlines():
965 ...do something to line...
966
Tim Peters36cdad12000-12-29 02:06:45 +0000967- The bisect module has new functions bisect_left, insort_left,
968 bisect_right and insort_right. The old names bisect and insort
969 are now aliases for bisect_right and insort_right. XXX_right
970 and XXX_left methods differ in what happens when the new element
971 compares equal to one or more elements already in the list: the
972 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000973 right. Code that doesn't care where equal elements end up should
974 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000975
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000976- The new curses.panel module wraps the panel library that forms part
977 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
978
Guido van Rossumf61f1662001-01-10 20:13:55 +0000979- The SocketServer module now sets the allow_reuse_address flag by
980 default in the TCPServer class.
981
982- A new function, sys._getframe(), returns the stack frame pointer of
983 the caller. This is intended only as a building block for
984 higher-level mechanisms such as string interpolation.
985
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000986- The pyexpat module supports a number of new handlers, which are
987 available only in expat 1.2. If invocation of a callback fails, it
988 will report an additional frame in the traceback. Parser objects
989 participate now in garbage collection. If expat reports an unknown
990 encoding, pyexpat will try to use a Python codec; that works only
991 for single-byte charsets. The parser type objects is exposed as
992 XMLParserObject.
993
994- xml.dom now offers standard definitions for symbolic node type and
995 exception code constants, and a hierarchy of DOM exceptions. minidom
996 was adjusted to use them.
997
998- The conformance of xml.dom.minidom to the DOM specification was
999 improved. It detects a number of additional error cases; the
1000 previous/next relationship works even when the tree is modified;
1001 Node supports the normalize() method; NamedNodeMap, DocumentType and
1002 DOMImplementation classes were added; Element supports the
1003 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1004 method.
1005
Guido van Rossumf61f1662001-01-10 20:13:55 +00001006Build issues
1007
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001008- For Unix (and Unix-compatible) builds, configuration and building of
1009 extension modules is now greatly automated. Rather than having to
1010 edit the Modules/Setup file to indicate which modules should be
1011 built and where their include files and libraries are, a
1012 distutils-based setup.py script now takes care of building most
1013 extension modules. All extension modules built this way are built
1014 as shared libraries. Only a few modules that must be linked
1015 statically are still listed in the Setup file; you won't need to
1016 edit their configuration.
1017
1018- Python should now build out of the box on Cygwin. If it doesn't,
1019 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001020
1021- Python now always uses its own (renamed) implementation of getopt()
1022 -- there's too much variation among C library getopt()
1023 implementations.
1024
1025- C++ compilers are better supported; the CXX macro is always set to a
1026 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001027
Tim Petersd92dfe02000-12-12 01:18:41 +00001028Windows changes
1029
1030- select module: By default under Windows, a select() call
1031 can specify no more than 64 sockets. Python now boosts
1032 this Microsoft default to 512. If you need even more than
1033 that, see the MS docs (you'll need to #define FD_SETSIZE
1034 and recompile Python from source).
1035
Guido van Rossumf61f1662001-01-10 20:13:55 +00001036- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1037 subdirectory is no more!
1038
Tim Petersa3a3a032000-11-30 05:22:44 +00001039
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001040What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001041=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001042
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001043Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001044changes are in the file HISTORY. If you are making the jump directly
1045from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1046HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001047
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001048Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1049the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1050http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001051
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001052--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001053
1054======================================================================
1055
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001056What's new in 2.0 (since release candidate 1)?
1057==============================================
1058
1059Standard library
1060
1061- The copy_reg module was modified to clarify its intended use: to
1062 register pickle support for extension types, not for classes.
1063 pickle() will raise a TypeError if it is passed a class.
1064
1065- Fixed a bug in gettext's "normalize and expand" code that prevented
1066 it from finding an existing .mo file.
1067
1068- Restored support for HTTP/0.9 servers in httplib.
1069
Tim Peters989b7b92000-10-16 20:24:53 +00001070- The math module was changed to stop raising OverflowError in case of
1071 underflow, and return 0 instead in underflow cases. Whether Python
1072 used to raise OverflowError in case of underflow was platform-
1073 dependent (it did when the platform math library set errno to ERANGE
1074 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001075
1076- Fixed a bug in StringIO that occurred when the file position was not
1077 at the end of the file and write() was called with enough data to
1078 extend past the end of the file.
1079
1080- Fixed a bug that caused Tkinter error messages to get lost on
1081 Windows. The bug was fixed by replacing direct use of
1082 interp->result with Tcl_GetStringResult(interp).
1083
1084- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1085 redirect response.
1086
1087- Several changes were made to distutils: Some debugging code was
1088 removed from util. Fixed the installer used when an external zip
1089 program (like WinZip) is not found; the source code for this
1090 installer is in Misc/distutils. check_lib() was modified to behave
1091 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1092 test for whether installed modules are on sys.path was changed to
1093 use both normcase() and normpath().
1094
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001095- Several minor bugs were fixed in the xml package (the minidom,
1096 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001097
1098- The regression test driver (regrtest.py) behavior when invoked with
1099 -l changed: It now reports a count of objects that are recognized as
1100 garbage but not freed by the garbage collector.
1101
Tim Peters989b7b92000-10-16 20:24:53 +00001102- The regression test for the math module was changed to test
1103 exceptional behavior when the test is run in verbose mode. Python
1104 cannot yet guarantee consistent exception behavior across platforms,
1105 so the exception part of test_math is run only in verbose mode, and
1106 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001107
1108Internals
1109
1110- PyOS_CheckStack() has been disabled on Win64, where it caused
1111 test_sre to fail.
1112
1113Build issues
1114
1115- Changed compiler flags, so that gcc is always invoked with -Wall and
1116 -Wstrict-prototypes. Users compiling Python with GCC should see
1117 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001118 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001119 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001120
Tim Petersa3a3a032000-11-30 05:22:44 +00001121- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001122
1123Tools and other miscellany
1124
1125- The compiler in Tools/compiler was updated to support the new
1126 language features introduced in 2.0: extended print statement, list
1127 comprehensions, and augmented assignments. The new compiler should
1128 also be backwards compatible with Python 1.5.2; the compiler will
1129 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001130 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001131
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001132What's new in 2.0 release candidate 1 (since beta 2)?
1133=====================================================
1134
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001135What is release candidate 1?
1136
1137We believe that release candidate 1 will fix all known bugs that we
1138intend to fix for the 2.0 final release. This release should be a bit
1139more stable than the previous betas. We would like to see even more
1140widespread testing before the final release, so we are producing this
1141release candidate. The final release will be exactly the same unless
1142any show-stopping (or brown bag) bugs are found by testers of the
1143release candidate.
1144
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001145All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001146to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001147
1148Core language, builtins, and interpreter
1149
1150- A bug that caused crashes when __coerce__ was used with augmented
1151 assignment, e.g. +=, was fixed.
1152
1153- Raise ZeroDivisionError when raising zero to a negative number,
1154 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1155 power operator and the result of math.pow(0.0, -2.0) will vary by
1156 platform. On Linux, it raises a ValueError.
1157
1158- A bug in Unicode string interpolation was fixed that occasionally
1159 caused errors with formats including "%%". For example, the
1160 following expression "%% %s" % u"abc" no longer raises a TypeError.
1161
1162- Compilation of deeply nested expressions raises MemoryError instead
1163 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1164
1165- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1166 rendering them useless. They are now written in binary mode again.
1167
1168Standard library
1169
1170- Keyword arguments are now accepted for most pattern and match object
1171 methods in SRE, the standard regular expression engine.
1172
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001173- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001174 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001175
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001176- Several bugs in the Unicode handling and error handling in _tkinter
1177 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001178
1179- Fix memory management errors in Merge() and Tkapp_Call() routines.
1180
1181- Several changes were made to cStringIO to make it compatible with
1182 the file-like object interface and with StringIO. If operations are
1183 performed on a closed object, an exception is raised. The truncate
1184 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001185 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001186
1187- There were many changes made to the linuxaudiodev module and its
1188 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001189 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001190
1191 Note that this module is named poorly, because it should work
1192 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001193 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001194
1195 The module now raises exceptions when errors occur instead of
1196 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1197 audio) and defines a getptr() method that calls the
1198 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1199
1200- The library_version attribute, introduced in an earlier beta, was
1201 removed because it can not be supported with early versions of the C
1202 readline library, which provides no way to determine the version at
1203 compile-time.
1204
1205- The binascii module is now enabled on Win64.
1206
Tim Peters46446d62000-10-09 21:19:31 +00001207- tokenize.py no longer suffers "recursion depth" errors when parsing
1208 programs with very long string literals.
1209
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001210Internals
1211
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001212- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001213 which is called when the interpreter starts up to determine where
1214 the standard library is installed. These vulnerabilities affect all
1215 previous versions of Python and can be exploited by setting very
1216 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1217 setuid Python script, although use of the wrapper in
1218 Misc/setuid-prog.c will eliminate the vulnerability.
1219
1220- Fixed garbage collection bugs in instance creation that were
1221 triggered when errors occurred during initialization. The solution,
1222 applied in cPickle and in PyInstance_New(), is to call
1223 PyObject_GC_Init() after the initialization of the object's
1224 container attributes is complete.
1225
1226- pyexpat adds definitions of PyModule_AddStringConstant and
1227 PyModule_AddObject if the Python version is less than 2.0, which
1228 provides compatibility with PyXML on Python 1.5.2.
1229
1230- If the platform has a bogus definition for LONG_BIT (the number of
1231 bits in a long), an error will be reported at compile time.
1232
1233- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1234 collection crashes and possibly other, unreported crashes.
1235
1236- Fixed a memory leak in _PyUnicode_Fini().
1237
1238Build issues
1239
1240- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001241 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001242 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001243
1244- The mmap.PAGESIZE constant is now initialized using sysconf when
1245 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1246
1247- The md5 file should now compile on all platforms.
1248
1249- The select module now compiles on platforms that do not define
1250 POLLRDNORM and related constants.
1251
1252- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001253 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001254
Jeremy Hylton10921202000-10-09 18:34:12 +00001255- BeOS: A number of changes were made to the build and installation
1256 process. ar-fake now operates on a directory of object files.
1257 dl_export.h is gone, and its macros now appear on the mwcc command
1258 line during build on PPC BeOS.
1259
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001260- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001261 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001262
1263- Cygwin: Support for shared libraries, Tkinter, and sockets.
1264
1265- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1266
1267Tools and other miscellany
1268
1269- Removed debugging prints from main used with freeze.
1270
Tim Peters46446d62000-10-09 21:19:31 +00001271- IDLE auto-indent no longer crashes when it encounters Unicode
1272 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001273
1274What's new in 2.0 beta 2 (since beta 1)?
1275========================================
1276
1277Core language, builtins, and interpreter
1278
Tim Peters482c0212000-09-26 06:33:09 +00001279- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001280 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001281
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001282- Add -h and -V command line options to print the usage message and
1283 Python version number and exit immediately.
1284
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001285- eval() and exec accept Unicode objects as code parameters.
1286
1287- getattr() and setattr() now also accept Unicode objects for the
1288 attribute name, which are converted to strings using the default
1289 encoding before lookup.
1290
1291- Multiplication on string and Unicode now does proper bounds
1292 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1293 string is too long."
1294
1295- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001296 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001297
Jeremy Hylton1b618592000-09-26 05:32:36 +00001298
1299Standard library and extensions
1300
Guido van Rossum5b08f132001-04-16 02:05:23 +00001301- socket module: the OpenSSL code now adds support for RAND_status()
1302 and EGD (Entropy Gathering Device).
1303
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001304- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001305 argument checking; it still takes no arguments.
1306
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001307- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001308
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001309- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001310
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001311- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001312
1313- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001314 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001315
1316- copy: Copy Unicode objects atomically.
1317
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001318- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001319
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001320- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001321
Fred Drake67233bc2000-09-26 16:40:27 +00001322- dbm: Add get() and setdefault() methods to dbm object. Add constant
1323 `library' to module that names the library used. Added doc strings
1324 and method names to error messages. Uses configure to determine
1325 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1326 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001327
1328- distutils: Update to version 0.9.3.
1329
1330- dl: Add several dl.RTLD_ constants.
1331
1332- fpectl: Now supported on FreeBSD.
1333
1334- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1335 found by the collector will be saved in gc.garbage. This is useful
1336 for debugging a program that creates reference cycles.
1337
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001338- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001339 of HTTP class. Do not close socket on zero-length response. Do not
1340 crash when server sends invalid content-length header.
1341
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001342- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001343
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001344- marshal: When reading a short, sign-extend on platforms where shorts
1345 are bigger than 16 bits. When reading a long, repair the unportable
1346 sign extension that was being done for 64-bit machines. (It assumed
1347 that signed right shift sign-extends.)
1348
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001349- operator: Add contains(), invert(), __invert__() as aliases for
1350 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001351
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001352- os: Add support for popen2() and popen3() on all platforms where
1353 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001354
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001355- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001356 clicking on a file in Explorer (or passing the file name to the
1357 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001358
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001359- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001360 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001361
1362- pickle: Now raises ValueError when an invalid pickle that contains
1363 a non-string repr where a string repr was expected. This behavior
1364 matches cPickle.
1365
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001366- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001367
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001368- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001369
1370- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001371 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001372 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001373
1374- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001375 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001376
1377- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001378 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001379 few cycles during startup since the first call to
1380 setdefaultencoding() will initialize the codec registry and the
1381 encodings package.
1382
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001383- socket: Support for size hint in readlines() method of object returned
1384 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001385
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001386- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001387 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001388 is followed by whitespace.
1389
Tim Petersa3a3a032000-11-30 05:22:44 +00001390- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001391
1392- struct: Check ranges for bytes and shorts.
1393
1394- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001395 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001396
1397- Tkinter: Image objects are now guaranteed to have unique ids. Set
1398 event.delta to zero if Tk version doesn't support mousewheel.
1399 Removed some debugging prints.
1400
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001401- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001402
Fred Drake67233bc2000-09-26 16:40:27 +00001403- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001404 which works around a bug in Norton AntiVirus 2000 that leads directly
1405 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001406
1407- xml: New version detection code allows PyXML to override standard
1408 XML package if PyXML version is greater than 0.6.1.
1409
Fred Drake64bb3802000-09-26 16:21:35 +00001410- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1411 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1412 tree only for nodes which are sufficiently interesting to a specific
1413 application. Does not provide the HTML-specific extensions. Still
1414 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001415
Fred Drake64bb3802000-09-26 16:21:35 +00001416- xml.sax: SAX 2 support for Python, including all the handler
1417 interfaces needed to process XML 1.0 compliant XML. Some
1418 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001419
Fred Drake64bb3802000-09-26 16:21:35 +00001420- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1421 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001422
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001423
Jeremy Hylton1b618592000-09-26 05:32:36 +00001424C API
1425
1426- Add three new convenience functions for module initialization --
1427 PyModule_AddObject(), PyModule_AddIntConstant(), and
1428 PyModule_AddStringConstant().
1429
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001430- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001431 removed and add #error to Python.h if NULL isn't defined after
1432 #include of stdio.h.
1433
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001434- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001435 backwards compatibility (at the source level) with old extensions.
1436
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001437- A wrapper API was added for signal() and sigaction(). Instead of
1438 either function, always use PyOS_getsig() to get a signal handler
1439 and PyOS_setsig() to set one. A new convenience typedef
1440 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001441
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001442- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001443 internal data buffer and size of a string object -- or the default
1444 encoded version of a Unicode object.
1445
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001446- PyString_Size() and PyString_AsString() accept Unicode objects.
1447
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001448- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001449 exists). INT_MAX and LONG_MAX will always be defined, even if
1450 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001451
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001452- PyFloat_FromString takes a second argument, pend, that was
1453 effectively useless. It is now officially useless but preserved for
1454 backwards compatibility. If the pend argument is not NULL, *pend is
1455 set to NULL.
1456
1457- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1458 for the attribute name. See note on getattr() above.
1459
1460- A few bug fixes to argument processing for Unicode.
1461 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1462 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1463 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001464 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001465
1466- Py_BuildValue accepts B format (for bgen-generated code).
1467
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001468
Jeremy Hylton1b618592000-09-26 05:32:36 +00001469Internals
1470
1471- On Unix, fix code for finding Python installation directory so that
1472 it works when argv[0] is a relative path.
1473
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001474- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001475 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001476 rather than by generating a copy of the object.
1477
Tim Peters482c0212000-09-26 06:33:09 +00001478- Several of the internal Unicode tables are much smaller now, and
1479 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001480
Jeremy Hylton97693b02000-09-26 17:42:51 +00001481- In the garbage collector: Fixed bug in collection of tuples. Fixed
1482 bug that caused some instances to be removed from the container set
1483 while they were still live. Fixed parsing in gc.set_debug() for
1484 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001485
1486- Fixed refcount problem in instance deallocation that only occurred
1487 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1488
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001489- On Windows, getpythonregpath is now protected against null data in
1490 registry key.
1491
1492- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001493 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001494
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001495
Jeremy Hylton1b618592000-09-26 05:32:36 +00001496Build and platform-specific issues
1497
1498- Better support of GNU Pth via --with-pth configure option.
1499
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001500- Python/C API now properly exposed to dynamically-loaded extension
1501 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001502
1503- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1504 Don't define MS_SYNC to be zero when it is undefined. Added missing
1505 prototypes in posixmodule.c.
1506
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001507- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001508 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001509
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001510- Fix largefile support on older NetBSD systems and OpenBSD by adding
1511 define for TELL64.
1512
1513
1514Tools and other miscellany
1515
1516- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1517
1518- freeze: The modulefinder now works with 2.0 opcodes.
1519
Tim Petersa3a3a032000-11-30 05:22:44 +00001520- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001521 Move hackery of sys.argv until after the Tk instance has been
1522 created, which allows the application-specific Tkinter
1523 initialization to be executed if present; also pass an explicit
1524 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001525
Jeremy Hylton1b618592000-09-26 05:32:36 +00001526
1527What's new in 2.0 beta 1?
1528=========================
1529
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001530Source Incompatibilities
1531------------------------
1532
1533None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1534such as single-argument append(), connect() and bind(), and changes to
1535str(long) and repr(float).
1536
1537
1538Binary Incompatibilities
1539------------------------
1540
1541- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1542with Python 2.0; these extensions will have to be rebuilt for Python
15432.0.
1544
1545- On Windows, attempting to import a third party extension built for
1546Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1547can do about this. Check your PYTHONPATH environment variable!
1548
1549- Python bytecode files (*.pyc and *.pyo) are not compatible between
1550releases.
1551
1552
1553Overview of Changes Since 1.6
1554-----------------------------
1555
1556There are many new modules (including brand new XML support through
1557the xml package, and i18n support through the gettext module); a list
1558of all new modules is included below. Lots of bugs have been fixed.
1559
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001560The process for making major new changes to the language has changed
1561since Python 1.6. Enhancements must now be documented by a Python
1562Enhancement Proposal (PEP) before they can be accepted.
1563
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001564There are several important syntax enhancements, described in more
1565detail below:
1566
1567 - Augmented assignment, e.g. x += 1
1568
1569 - List comprehensions, e.g. [x**2 for x in range(10)]
1570
1571 - Extended import statement, e.g. import Module as Name
1572
1573 - Extended print statement, e.g. print >> file, "Hello"
1574
1575Other important changes:
1576
1577 - Optional collection of cyclical garbage
1578
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001579Python Enhancement Proposal (PEP)
1580---------------------------------
1581
1582PEP stands for Python Enhancement Proposal. A PEP is a design
1583document providing information to the Python community, or describing
1584a new feature for Python. The PEP should provide a concise technical
1585specification of the feature and a rationale for the feature.
1586
1587We intend PEPs to be the primary mechanisms for proposing new
1588features, for collecting community input on an issue, and for
1589documenting the design decisions that have gone into Python. The PEP
1590author is responsible for building consensus within the community and
1591documenting dissenting opinions.
1592
1593The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001594
1595Augmented Assignment
1596--------------------
1597
1598This must have been the most-requested feature of the past years!
1599Eleven new assignment operators were added:
1600
Guido van Rossume905e952000-09-05 12:42:46 +00001601 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001602
1603For example,
1604
1605 A += B
1606
1607is similar to
1608
1609 A = A + B
1610
1611except that A is evaluated only once (relevant when A is something
1612like dict[index].attr).
1613
1614However, if A is a mutable object, A may be modified in place. Thus,
1615if A is a number or a string, A += B has the same effect as A = A+B
1616(except A is only evaluated once); but if a is a list, A += B has the
1617same effect as A.extend(B)!
1618
1619Classes and built-in object types can override the new operators in
1620order to implement the in-place behavior; the not-in-place behavior is
1621used automatically as a fallback when an object doesn't implement the
1622in-place behavior. For classes, the method name is derived from the
1623method name for the corresponding not-in-place operator by inserting
1624an 'i' in front of the name, e.g. __iadd__ implements in-place
1625__add__.
1626
1627Augmented assignment was implemented by Thomas Wouters.
1628
1629
1630List Comprehensions
1631-------------------
1632
1633This is a flexible new notation for lists whose elements are computed
1634from another list (or lists). The simplest form is:
1635
1636 [<expression> for <variable> in <sequence>]
1637
Guido van Rossum56db0952000-09-06 23:34:25 +00001638For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001639This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001640
1641You can also add a condition:
1642
1643 [<expression> for <variable> in <sequence> if <condition>]
1644
1645For example, [w for w in words if w == w.lower()] would yield the list
1646of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001647than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001648
1649You can also have nested for loops and more than one 'if' clause. For
1650example, here's a function that flattens a sequence of sequences::
1651
1652 def flatten(seq):
1653 return [x for subseq in seq for x in subseq]
1654
1655 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1656
1657This prints
1658
1659 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1660
1661List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001662Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001663
1664
1665Extended Import Statement
1666-------------------------
1667
1668Many people have asked for a way to import a module under a different
1669name. This can be accomplished like this:
1670
1671 import foo
1672 bar = foo
1673 del foo
1674
1675but this common idiom gets old quickly. A simple extension of the
1676import statement now allows this to be written as follows:
1677
1678 import foo as bar
1679
1680There's also a variant for 'from ... import':
1681
1682 from foo import bar as spam
1683
1684This also works with packages; e.g. you can write this:
1685
1686 import test.regrtest as regrtest
1687
1688Note that 'as' is not a new keyword -- it is recognized only in this
1689context (this is only possible because the syntax for the import
1690statement doesn't involve expressions).
1691
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001692Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001693
1694
1695Extended Print Statement
1696------------------------
1697
1698Easily the most controversial new feature, this extension to the print
1699statement adds an option to make the output go to a different file
1700than the default sys.stdout.
1701
1702For example, to write an error message to sys.stderr, you can now
1703write:
1704
1705 print >> sys.stderr, "Error: bad dog!"
1706
1707As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001708evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001709
1710 print >> None, "Hello world"
1711
1712is equivalent to
1713
1714 print "Hello world"
1715
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001716Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001717
1718
1719Optional Collection of Cyclical Garbage
1720---------------------------------------
1721
1722Python is now equipped with a garbage collector that can hunt down
1723cyclical references between Python objects. It's no replacement for
1724reference counting; in fact, it depends on the reference counts being
1725correct, and decides that a set of objects belong to a cycle if all
1726their reference counts can be accounted for from their references to
1727each other. This devious scheme was first proposed by Eric Tiedemann,
1728and brought to implementation by Neil Schemenauer.
1729
1730There's a module "gc" that lets you control some parameters of the
1731garbage collection. There's also an option to the configure script
1732that lets you enable or disable the garbage collection. In 2.0b1,
1733it's on by default, so that we (hopefully) can collect decent user
1734experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001735performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001736off by default in the final 2.0 release.
1737
1738
1739Smaller Changes
1740---------------
1741
1742A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1743map(None, seq1, seq2, ...) when the sequences have the same length;
1744i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1745the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001746zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001747
1748sys.version_info is a tuple (major, minor, micro, level, serial).
1749
1750Dictionaries have an odd new method, setdefault(key, default).
1751dict.setdefault(key, default) returns dict[key] if it exists; if not,
1752it sets dict[key] to default and returns that value. Thus:
1753
1754 dict.setdefault(key, []).append(item)
1755
1756does the same work as this common idiom:
1757
1758 if not dict.has_key(key):
1759 dict[key] = []
1760 dict[key].append(item)
1761
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001762There are two new variants of SyntaxError that are raised for
1763indentation-related errors: IndentationError and TabError.
1764
1765Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1766escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001767
1768The limits on the size of expressions and file in Python source code
1769have been raised from 2**16 to 2**32. Previous versions of Python
1770were limited because the maximum argument size the Python VM accepted
1771was 2**16. This limited the size of object constructor expressions,
1772e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1773limit was raised thanks to a patch by Charles Waldman that effectively
1774fixes the problem. It is now much more likely that you will be
1775limited by available memory than by an arbitrary limit in Python.
1776
1777The interpreter's maximum recursion depth can be modified by Python
1778programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1779limit is the maximum number of recursive calls that can be made by
1780Python code. The limit exists to prevent infinite recursion from
1781overflowing the C stack and causing a core dump. The default value is
17821000. The maximum safe value for a particular platform can be found
1783by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001784
1785New Modules and Packages
1786------------------------
1787
1788atexit - for registering functions to be called when Python exits.
1789
1790imputil - Greg Stein's alternative API for writing custom import
1791hooks.
1792
1793pyexpat - an interface to the Expat XML parser, contributed by Paul
1794Prescod.
1795
1796xml - a new package with XML support code organized (so far) in three
1797subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1798would fill a volume. There's a special feature whereby a
1799user-installed package named _xmlplus overrides the standard
1800xmlpackage; this is intended to give the XML SIG a hook to distribute
1801backwards-compatible updates to the standard xml package.
1802
1803webbrowser - a platform-independent API to launch a web browser.
1804
1805
Guido van Rossume905e952000-09-05 12:42:46 +00001806Changed Modules
1807---------------
1808
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001809array -- new methods for array objects: count, extend, index, pop, and
1810remove
1811
1812binascii -- new functions b2a_hex and a2b_hex that convert between
1813binary data and its hex representation
1814
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001815calendar -- Many new functions that support features including control
1816over which day of the week is the first day, returning strings instead
1817of printing them. Also new symbolic constants for days of week,
1818e.g. MONDAY, ..., SUNDAY.
1819
1820cgi -- FieldStorage objects have a getvalue method that works like a
1821dictionary's get method and returns the value attribute of the object.
1822
1823ConfigParser -- The parser object has new methods has_option,
1824remove_section, remove_option, set, and write. They allow the module
1825to be used for writing config files as well as reading them.
1826
1827ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001828optionally support the RFC 959 REST command.
1829
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001830gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001831
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001832httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1833the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001834
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001835locale -- implement getdefaultlocale for Win32 and Macintosh
1836
1837marshal -- no longer dumps core when marshaling deeply nested or
1838recursive data structures
1839
1840os -- new functions isatty, seteuid, setegid, setreuid, setregid
1841
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001842os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1843support under Unix.
1844
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001845os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001846
1847os.path -- fix semantics of os.path.commonprefix
1848
1849smtplib -- support for sending very long messages
1850
1851socket -- new function getfqdn()
1852
1853readline -- new functions to read, write and truncate history files.
1854The readline section of the library reference manual contains an
1855example.
1856
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001857select -- add interface to poll system call
1858
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001859shutil -- new copyfileobj function
1860
1861SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1862HTTP server.
1863
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001864Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001865
1866urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001867e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001868
1869whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001870
1871
1872Obsolete Modules
1873----------------
1874
1875None. However note that 1.6 made a whole slew of modules obsolete:
1876stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1877poly, zmod, strop, util, whatsound.
1878
1879
1880Changed, New, Obsolete Tools
1881----------------------------
1882
Tim Peters8b092332000-09-05 20:15:25 +00001883None.
Guido van Rossume905e952000-09-05 12:42:46 +00001884
1885
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001886C-level Changes
1887---------------
1888
1889Several cleanup jobs were carried out throughout the source code.
1890
1891All C code was converted to ANSI C; we got rid of all uses of the
1892Py_PROTO() macro, which makes the header files a lot more readable.
1893
1894Most of the portability hacks were moved to a new header file,
1895pyport.h; several other new header files were added and some old
1896header files were removed, in an attempt to create a more rational set
1897of header files. (Few of these ever need to be included explicitly;
1898they are all included by Python.h.)
1899
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001900Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001901and Win64, especially for the new Intel Itanium processor. Mick also
1902added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001903
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001904The C APIs to return an object's size have been update to consistently
1905use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1906previous versions, the abstract interfaces used PyXXX_Length and the
1907concrete interfaces used PyXXX_Size. The old names,
1908e.g. PyObject_Length, are still available for backwards compatibility
1909at the API level, but are deprecated.
1910
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001911The PyOS_CheckStack function has been implemented on Windows by
1912Fredrik Lundh. It prevents Python from failing with a stack overflow
1913on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001914
1915The GC changes resulted in creation of two new slots on object,
1916tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001917the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001918
1919The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001920C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001921
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001922PyErr_Format has been updated to automatically calculate the size of
1923the buffer needed to hold the formatted result string. This change
1924prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001925
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001926New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001927
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001928PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1929that are the same as their non-Ex counterparts except they take an
1930extra flag argument that tells them to close the file when done.
1931
1932XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001933
Tim Peters8b092332000-09-05 20:15:25 +00001934
1935Windows Changes
1936---------------
1937
1938New popen2/popen3/peopen4 in os module (see Changed Modules above).
1939
1940os.popen is much more usable on Windows 95 and 98. See Microsoft
1941Knowledge Base article Q150956. The Win9x workaround described there
1942is implemented by the new w9xpopen.exe helper in the root of your
1943Python installation. Note that Python uses this internally; it is not
1944a standalone program.
1945
1946Administrator privileges are no longer required to install Python
1947on Windows NT or Windows 2000. If you have administrator privileges,
1948Python's registry info will be written under HKEY_LOCAL_MACHINE.
1949Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001950under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001951uses of Python, but will prevent some advanced uses from working
1952(for example, running a Python script as an NT service, or possibly
1953from CGI).
1954
1955[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1956installer; instead, it installs the needed Tcl/Tk files directly in the
1957Python directory. If you already have a Tcl/Tk installation, this
1958wastes some disk space (about 4 Megs) but avoids problems with
1959conflicting Tcl/Tk installations, and makes it much easier for Python
1960to ensure that Tcl/Tk can find all its files.
1961
1962[This was new in 1.6] The Windows installer now installs by default in
1963\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1964
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001965
1966Updates to the changes between 1.5.2 and 1.6
1967--------------------------------------------
1968
1969The 1.6 NEWS file can't be changed after the release is done, so here
1970is some late-breaking news:
1971
1972New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1973and changes to getlocale() and setlocale().
1974
1975The new module is now enabled per default.
1976
1977It is not true that the encodings codecs cannot be used for normal
1978strings: the string.encode() (which is also present on 8-bit strings
1979!) allows using them for 8-bit strings too, e.g. to convert files from
1980cp1252 (Windows) to latin-1 or vice-versa.
1981
1982Japanese codecs are available from Tamito KAJIYAMA:
1983http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1984
1985
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001986======================================================================