blob: b9601175855c87aa573e84b86fd38c0874c67800 [file] [log] [blame]
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).
18
19 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 Peters15d49292001-05-27 07:39:22 +0000119- Collisions in dicts now use polynomial division instead of multiplication
120 to generate the probe sequence, following an idea of Christian Tismer's.
121 This allows all bits of the hash code to come into play. It should have
122 little or no effect on speed in ordinary cases, but can help dramatically
123 in bad cases. For example, looking up every key in a dict d with
124 d.keys() = [i << 16 for i in range(20000)] is approximately 500x faster
125 now.
126
Tim Petersa814db52001-05-14 07:05:58 +0000127Library
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
Guido van Rossumffe13be2001-04-16 18:46:45 +0000158What's New in Python 2.1 (final)?
159=================================
160
161We only changed a few things since the last release candidate, all in
162Python library code:
163
164- A bug in the locale module was fixed that affected locales which
165 define no grouping for numeric formatting.
166
167- A few bugs in the weakref module's implementations of weak
168 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
169 and the test suite was updated to check for these bugs.
170
171- An old bug in the os.path.walk() function (introduced in Python
172 2.0!) was fixed: a non-existent file would cause an exception
173 instead of being ignored.
174
175- Fixed a few bugs in the new symtable module found by Neil Norwitz's
176 PyChecker.
177
178
Guido van Rossum5b08f132001-04-16 02:05:23 +0000179What's New in Python 2.1c2?
180===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000181
Guido van Rossum5b08f132001-04-16 02:05:23 +0000182A flurry of small changes, and one showstopper fixed in the nick of
183time made it necessary to release another release candidate. The list
184here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000185
Guido van Rossum5b08f132001-04-16 02:05:23 +0000186Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000187
Guido van Rossum5b08f132001-04-16 02:05:23 +0000188- Tim discovered a nasty bug in the dictionary code, caused by
189 PyDict_Next() calling dict_resize(), and the GC code's use of
190 PyDict_Next() violating an assumption in dict_items(). This was
191 fixed with considerable amounts of band-aid, but the net effect is a
192 saner and more robust implementation.
193
194- Made a bunch of symbols static that were accidentally global.
195
196Build and Ports
197
198- The setup.py script didn't check for a new enough version of zlib
199 (1.1.3 is needed). Now it does.
200
201- Changed "make clean" target to also remove shared libraries.
202
203- Added a more general warning about the SGI Irix optimizer to README.
204
205Library
206
207- Fix a bug in urllib.basejoin("http://host", "../file.html") which
208 omitted the slash between host and file.html.
209
210- The mailbox module's _Mailbox class contained a completely broken
211 and undocumented seek() method. Ripped it out.
212
213- Fixed a bunch of typos in various library modules (urllib2, smtpd,
214 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
215
216- Fixed a few last-minute bugs in unittest.
217
218Extensions
219
220- Reverted the patch to the OpenSSL code in socketmodule.c to support
221 RAND_status() and the EGD, and the subsequent patch that tried to
222 fix it for pre-0.9.5 versions; the problem with the patch is that on
223 some systems it issues a warning whenever socket is imported, and
224 that's unacceptable.
225
226Tests
227
228- Fixed the pickle tests to work with "import test.test_pickle".
229
230- Tweaked test_locale.py to actually run the test Windows.
231
232- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
233 not "wb" (which is not a valid mode at all).
234
235- Fix pstats browser crashes. Import readline if it exists to make
236 the user interface nicer.
237
238- Add "import thread" to the top of test modules that import the
239 threading module (test_asynchat and test_threadedtempfile). This
240 prevents test failures caused by a broken threading module resulting
241 from a previously caught failed import.
242
243- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
244 needed on some platforms (e.g. Solaris 8) when the tests are run
245 twice in succession.
246
247- Skip rather than fail test_sunaudiodev if no audio device is found.
248
249
250What's New in Python 2.1c1?
251===========================
252
253This list was significantly updated when 2.1c2 was released; the 2.1c1
254release didn't mention most changes that were actually part of 2.1c1:
255
256Legal
257
258- Copyright was assigned to the Python Software Foundation (PSF) and a
259 PSF license (very similar to the CNRI license) was added.
260
261- The CNRI copyright notice was updated to include 2001.
262
263Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000264
Guido van Rossumc9932722001-04-12 02:31:27 +0000265- After a public outcry, assignment to __debug__ is no longer illegal;
266 instead, a warning is issued. It will become illegal in 2.2.
267
Guido van Rossum5b08f132001-04-16 02:05:23 +0000268- Fixed a core dump with "%#x" % 0, and changed the semantics so that
269 "%#x" now always prepends "0x", even if the value is zero.
270
271- Fixed some nits in the bytecode compiler.
272
273- Fixed core dumps when calling certain kinds of non-functions.
274
275- Fixed various core dumps caused by reference count bugs.
276
277Build and Ports
278
279- Use INSTALL_SCRIPT to install script files.
280
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000281- New port: SCO Unixware 7, by Billy G. Allie.
282
Guido van Rossum5b08f132001-04-16 02:05:23 +0000283- Updated RISCOS port.
284
285- Updated BeOS port and notes.
286
287- Various other porting problems resolved.
288
289Library
290
291- The TERMIOS and SOCKET modules are now truly obsolete and
292 unnecessary. Their symbols are incorporated in the termios and
293 socket modules.
294
295- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
296 better tests for pickling.
297
298- threading: make Condition.wait() robust against KeyboardInterrupt.
299
300- zipfile: add support to zipfile to support opening an archive
301 represented by an open file rather than a file name. Fix bug where
302 the archive was not properly closed. Fixed a bug in this bugfix
303 where flush() was called for a read-only file.
304
305- imputil: added an uninstall() method to the ImportManager.
306
307- Canvas: fixed bugs in lower() and tkraise() methods.
308
309- SocketServer: API change (added overridable close_request() method)
310 so that the TCP server can explicitly close the request.
311
312- pstats: Eric Raymond added a simple interactive statistics browser,
313 invoked when the module is run as a script.
314
315- locale: fixed a problem in format().
316
317- webbrowser: made it work when the BROWSER environment variable has a
318 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
319 KDE 2. Fixed some other nits.
320
321- unittest: changes to allow using a different exception than
322 AssertionError, and added a few more function aliases. Some other
323 small changes.
324
325- urllib, urllib2: fixed redirect problems and a coupleof other nits.
326
327- asynchat: fixed a critical bug in asynchat that slipped through the
328 2.1b2 release. Fixed another rare bug.
329
330- Fix some unqualified except: clauses (always a bad code example).
331
332XML
333
334- pyexpat: new API get_version_string().
335
336- Fixed some minidom bugs.
337
338Extensions
339
340- Fixed a core dump in _weakref. Removed the weakref.mapping()
341 function (it adds nothing to the API).
342
343- Rationalized the use of header files in the readline module, to make
344 it compile (albeit with some warnings) with the very recent readline
345 4.2, without breaking for earlier versions.
346
347- Hopefully fixed a buffering problem in linuxaudiodev.
348
349- Attempted a fix to make the OpenSSL support in the socket module
350 work again with pre-0.9.5 versions of OpenSSL.
351
352Tests
353
354- Added a test case for asynchat and asyncore.
355
356- Removed coupling between tests where one test failing could break
357 another.
358
359Tools
360
361- Ping added an interactive help browser to pydoc, fixed some nits
362 in the rest of the pydoc code, and added some features to his
363 inspect module.
364
365- An updated python-mode.el version 4.1 which integrates Ken
366 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
367 much nicer in XEmacs and Emacs. When stepping through your program
368 with pdb, in either the shell window or the *Python* window, the
369 source file and line will be tracked by an arrow. Very cool!
370
371- IDLE: syntax warnings in interactive mode are changed into errors.
372
373- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000374 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000375
376- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000377
Barry Warsaw11e89c72001-04-11 20:37:57 +0000378
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000379What's New in Python 2.1 beta 2?
380================================
381
Guido van Rossum053ae352001-03-22 14:17:21 +0000382(Unlisted are many fixed bugs, more documentation, etc.)
383
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000384Core language, builtins, and interpreter
385
Guido van Rossum053ae352001-03-22 14:17:21 +0000386- The nested scopes work (enabled by "from __future__ import
387 nested_scopes") is completed; in particular, the future now extends
388 into code executed through exec, eval() and execfile(), and into the
389 interactive interpreter.
390
391- When calling a base class method (e.g. BaseClass.__init__(self)),
392 this is now allowed even if self is not strictly spoken a class
393 instance (e.g. when using metaclasses or the Don Beaudry hook).
394
395- Slice objects are now comparable but not hashable; this prevents
396 dict[:] from being accepted but meaningless.
397
398- Complex division is now calculated using less braindead algorithms.
399 This doesn't change semantics except it's more likely to give useful
400 results in extreme cases. Complex repr() now uses full precision
401 like float repr().
402
403- sgmllib.py now calls handle_decl() for simple <!...> declarations.
404
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000405- It is illegal to assign to the name __debug__, which is set when the
406 interpreter starts. It is effectively a compile-time constant.
407
408- A warning will be issued if a global statement for a variable
409 follows a use or assignment of that variable.
410
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000411Standard library
412
Guido van Rossum053ae352001-03-22 14:17:21 +0000413- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
414 inspired by JUnit), is now part of the standard library. You now
415 have a choice of two testing frameworks: unittest requires you to
416 write testcases as separate code, doctest gathers them from
417 docstrings. Both approaches have their advantages and
418 disadvantages.
419
420- A new module Tix was added, which wraps the Tix extension library
421 for Tk. With that module, it is not necessary to statically link
422 Tix with _tkinter, since Tix will be loaded with Tcl's "package
423 require" command. See Demo/tix/.
424
425- tzparse.py is now obsolete.
426
427- In gzip.py, the seek() and tell() methods are removed -- they were
428 non-functional anyway, and it's better if callers can test for their
429 existence with hasattr().
430
431Python/C API
432
433- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
434 that's already in the dictionary during a PyDict_Next() iteration.
435 This used to fail occasionally when a dictionary resize operation
436 could be triggered that would rehash all the keys. All other
437 modifications to the dictionary are still off-limits during a
438 PyDict_Next() iteration!
439
440- New extended APIs related to passing compiler variables around.
441
442- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
443 implement isinstance() and issubclass().
444
445- Py_BuildValue() now has a "D" conversion to create a Python complex
446 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000447
Fred Drake4e262a92001-03-22 18:26:47 +0000448- Extensions types which support weak references must now set the
449 field allocated for the weak reference machinery to NULL themselves;
450 this is done to avoid the cost of checking each object for having a
451 weakly referencable type in PyObject_INIT(), since most types are
452 not weakly referencable.
453
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000454- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
455 free variables and cell variables to and from the frame's f_locals.
456
457- Variants of several functions defined in pythonrun.h have been added
458 to support the nested_scopes future statement. The variants all end
459 in Flags and take an extra argument, a PyCompilerFlags *; examples:
460 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
461 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000462 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000463
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000464Distutils
465
466- the sdist command now writes a PKG-INFO file, as described in PEP 241,
467 into the release tree.
468
Tim Peters0e57abf2001-05-02 07:39:38 +0000469- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000470 (an uninstaller, more customization of the installer's display)
471
472- from Jack Jansen: added Mac-specific code to generate a dialog for
473 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000474 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000475 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000476
477- added 'platforms' and 'keywords' to the set of metadata that can be
478 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000479
480- applied patches from Jason Tishler to make the compiler class work with
481 Cygwin.
482
483
Tim Peters2fe289a2001-03-01 22:19:38 +0000484What's New in Python 2.1 beta 1?
485================================
Tim Petersd66595f2001-02-04 03:09:53 +0000486
487Core language, builtins, and interpreter
488
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000489- Following an outcry from the community about the amount of code
490 broken by the nested scopes feature introduced in 2.1a2, we decided
491 to make this feature optional, and to wait until Python 2.2 (or at
492 least 6 months) to make it standard. The option can be enabled on a
493 per-module basis by adding "from __future__ import nested_scopes" at
494 the beginning of a module (before any other statements, but after
495 comments and an optional docstring). See PEP 236 (Back to the
496 __future__) for a description of the __future__ statement. PEP 227
497 (Statically Nested Scopes) has been updated to reflect this change,
498 and to clarify the semantics in a number of endcases.
499
500- The nested scopes code, when enabled, has been hardened, and most
501 bugs and memory leaks in it have been fixed.
502
503- Compile-time warnings are now generated for a number of conditions
504 that will break or change in meaning when nested scopes are enabled:
505
506 - Using "from...import *" or "exec" without in-clause in a function
507 scope that also defines a lambda or nested function with one or
508 more free (non-local) variables. The presence of the import* or
509 bare exec makes it impossible for the compiler to determine the
510 exact set of local variables in the outer scope, which makes it
511 impossible to determine the bindings for free variables in the
512 inner scope. To avoid the warning about import *, change it into
513 an import of explicitly name object, or move the import* statement
514 to the global scope; to avoid the warning about bare exec, use
515 exec...in... (a good idea anyway -- there's a possibility that
516 bare exec will be deprecated in the future).
517
518 - Use of a global variable in a nested scope with the same name as a
519 local variable in a surrounding scope. This will change in
520 meaning with nested scopes: the name in the inner scope will
521 reference the variable in the outer scope rather than the global
522 of the same name. To avoid the warning, either rename the outer
523 variable, or use a global statement in the inner function.
524
Neil Schemenauera35c6882001-02-27 04:45:05 +0000525- An optional object allocator has been included. This allocator is
526 optimized for Python objects and should be faster and use less memory
527 than the standard system allocator. It is not enabled by default
528 because of possible thread safety problems. The allocator is only
529 protected by the Python interpreter lock and it is possible that some
530 extension modules require a thread safe allocator. The object
531 allocator can be enabled by providing the "--with-pymalloc" option to
532 configure.
533
Tim Petersd66595f2001-02-04 03:09:53 +0000534Standard library
535
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000536- pyexpat now detects the expat version if expat.h defines it. A
537 number of additional handlers are provided, which are only available
538 since expat 1.95. In addition, the methods SetParamEntityParsing and
539 GetInputContext of Parser objects are available with 1.95.x
540 only. Parser objects now provide the ordered_attributes and
541 specified_attributes attributes. A new module expat.model was added,
542 which offers a number of additional constants if 1.95.x is used.
543
544- xml.dom offers the new functions registerDOMImplementation and
545 getDOMImplementation.
546
547- xml.dom.minidom offers a toprettyxml method. A number of DOM
548 conformance issues have been resolved. In particular, Element now
549 has an hasAttributes method, and the handling of namespaces was
550 improved.
551
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000552- Ka-Ping Yee contributed two new modules: inspect.py, a module for
553 getting information about live Python code, and pydoc.py, a module
554 for interactively converting docstrings to HTML or text.
555 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000556 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000557 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
558 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000559
Tim Peters1eff7962001-03-01 02:31:33 +0000560- New library module difflib.py, primarily packaging the SequenceMatcher
561 class at the heart of the popular ndiff.py file-comparison tool.
562
563- doctest.py (a framework for verifying Python code examples in docstrings)
564 is now part of the std library.
565
Tim Petersd66595f2001-02-04 03:09:53 +0000566Windows changes
567
Guido van Rossume3955a82001-03-02 14:05:59 +0000568- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
569 small GUI that lets you browse the module docstrings using your
570 default web browser.
571
Tim Peters1eff7962001-03-01 02:31:33 +0000572- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
573 Platforms) is implemented. See
574
575 http://python.sourceforge.net/peps/pep-0235.html
576
577 for full details, especially the "Current Lower-Left Semantics" section.
578 The new Windows import rules are simpler than before:
579
580 A. If the PYTHONCASEOK environment variable exists, same as
581 before: silently accept the first case-insensitive match of any
582 kind; raise ImportError if none found.
583
584 B. Else search sys.path for the first case-sensitive match; raise
585 ImportError if none found.
586
587 The same rules have been implented on other platforms with case-
588 insensitive but case-preserving filesystems too (including Cygwin, and
589 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000590
Tim Peters25a9ce32001-02-19 07:06:36 +0000591- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
592 what it's supposed to do (and does do under NT and 2000) via direct
593 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000594 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000595 all Win9x systems before.
596
Tim Peters1eff7962001-03-01 02:31:33 +0000597- Build: Subproject _test (effectively) renamed to _testcapi.
598
Tim Peters2fe289a2001-03-01 22:19:38 +0000599New platforms
600
601- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
602 Thanks to Steven Majewski!
603
604- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
605 Tishler!
606
Guido van Rossum9089b272001-03-02 06:49:50 +0000607- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
608 Schwertberger! See RISCOS/README for more information -- it seems
609 that because of the bizarre filename conventions on RISCOS, no port
610 to that platform is easy. Note that the new variable os.endsep is
611 silently supported in order to make life easier on this platform,
612 but we don't advertise it because it's not worth for most folks to
613 care about RISCOS portability.
614
Tim Peters25a9ce32001-02-19 07:06:36 +0000615
Tim Petersd7b5e882001-01-25 03:36:26 +0000616What's New in Python 2.1 alpha 2?
617=================================
Tim Peters40ead762001-01-27 05:35:26 +0000618
Tim Petersd7b5e882001-01-25 03:36:26 +0000619Core language, builtins, and interpreter
620
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000621- Scopes nest. If a name is used in a function or class, but is not
622 local, the definition in the nearest enclosing function scope will
623 be used. One consequence of this change is that lambda statements
624 could reference variables in the namespaces where the lambda is
625 defined. In some unusual cases, this change will break code.
626
627 In all previous version of Python, names were resolved in exactly
628 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000629 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000630 function A is defined within a function B, the names bound in B are
631 not visible in A. The new rules make names bound in B visible in A,
632 unless A contains a name binding that hides the binding in B.
633
634 Section 4.1 of the reference manual describes the new scoping rules
635 in detail. The test script in Lib/test/test_scope.py demonstrates
636 some of the effects of the change.
637
638 The new rules will cause existing code to break if it defines nested
639 functions where an outer function has local variables with the same
640 name as globals or builtins used by the inner function. Example:
641
642 def munge(str):
643 def helper(x):
644 return str(x)
645 if type(str) != type(''):
646 str = helper(str)
647 return str.strip()
648
649 Under the old rules, the name str in helper() is bound to the
650 builtin function str(). Under the new rules, it will be bound to
651 the argument named str and an error will occur when helper() is
652 called.
653
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000654- The compiler will report a SyntaxError if "from ... import *" occurs
655 in a function or class scope. The language reference has documented
656 that this case is illegal, but the compiler never checked for it.
657 The recent introduction of nested scope makes the meaning of this
658 form of name binding ambiguous. In a future release, the compiler
659 may allow this form when there is no possibility of ambiguity.
660
Tim Peters40ead762001-01-27 05:35:26 +0000661- repr(string) is easier to read, now using hex escapes instead of octal,
662 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
663
664 >>> "\texample \r\n" + chr(0) + chr(255)
665 '\texample \r\n\x00\xff' # in 2.1
666 '\011example \015\012\000\377' # in 2.0
667
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000668- Functions are now compared and hashed by identity, not by value, since
669 the func_code attribute is writable.
670
Fred Drakefb9d7122001-02-01 20:00:40 +0000671- Weak references (PEP 205) have been added. This involves a few
672 changes in the core, an extension module (_weakref), and a Python
673 module (weakref). The weakref module is the public interface. It
674 includes support for "explicit" weak references, proxy objects, and
675 mappings with weakly held values.
676
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000677- A 'continue' statement can now appear in a try block within the body
678 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000679 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000680
Tim Petersd7b5e882001-01-25 03:36:26 +0000681Standard library
682
Barry Warsaw30dbd142001-01-31 22:14:01 +0000683- mailbox.py now has a new class, PortableUnixMailbox which is
684 identical to UnixMailbox but uses a more portable scheme for
685 determining From_ separators. Also, the constructors for all the
686 classes in this module have a new optional `factory' argument, which
687 is a callable used when new message classes must be instantiated by
688 the next() method.
689
Tim Petersd7b5e882001-01-25 03:36:26 +0000690- random.py is now self-contained, and offers all the functionality of
691 the now-deprecated whrandom.py. See the docs for details. random.py
692 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000693 and restoring the internal state of the generator; and jumpahead(n),
694 for quickly forcing the internal state to be the same as if n calls to
695 random() had been made. The latter is particularly useful for multi-
696 threaded programs, creating one instance of the random.Random() class for
697 each thread, then using .jumpahead() to force each instance to use a
698 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000699
Tim Peters0de88fc2001-02-01 04:59:18 +0000700- random.py's seed() function is new. For bit-for-bit compatibility with
701 prior releases, use the whseed function instead. The new seed function
702 addresses two problems: (1) The old function couldn't produce more than
703 about 2**24 distinct internal states; the new one about 2**45 (the best
704 that can be done in the Wichmann-Hill generator). (2) The old function
705 sometimes produced identical internal states when passed distinct
706 integers, and there was no simple way to predict when that would happen;
707 the new one guarantees to produce distinct internal states for all
708 arguments in [0, 27814431486576L).
709
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000710- The socket module now supports raw packets on Linux. The socket
711 family is AF_PACKET.
712
Tim Peters9ea17ac2001-02-02 05:57:15 +0000713- test_capi.py is a start at running tests of the Python C API. The tests
714 are implemented by the new Modules/_testmodule.c.
715
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000716- A new extension module, _symtable, provides provisional access to the
717 internal symbol table used by the Python compiler. A higher-level
718 interface will be added on top of _symtable in a future release.
719
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000720- Removed the obsolete soundex module.
721
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000722- xml.dom.minidom now uses the standard DOM exceptions. Node supports
723 the isSameNode method; NamedNodeMap the get method.
724
725- xml.sax.expatreader supports the lexical handler property; it
726 generates comment, startCDATA, and endCDATA events.
727
Tim Petersee826f82001-01-31 19:39:44 +0000728Windows changes
729
730- Build procedure: the zlib project is built in a different way that
731 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000732 the zlib binary used. See PCbuild\readme.txt for details. Your old
733 zlib-related directories can be deleted; you'll need to download fresh
734 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000735
Tim Peters9ea17ac2001-02-02 05:57:15 +0000736- Build: New subproject _test for the benefit of test_capi.py (see above).
737
Tim Petersb16c56f2001-02-02 21:24:51 +0000738- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
739 interface to some Python compiler internals).
740
741- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000742 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000743
Tim Petersa3a3a032000-11-30 05:22:44 +0000744What's New in Python 2.1 alpha 1?
745=================================
746
747Core language, builtins, and interpreter
748
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000749- There is a new Unicode companion to the PyObject_Str() API
750 called PyObject_Unicode(). It behaves in the same way as the
751 former, but assures that the returned value is an Unicode object
752 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000753
Guido van Rossumf98eda02001-01-17 15:54:45 +0000754- The comparison operators support "rich comparison overloading" (PEP
755 207). C extension types can provide a rich comparison function in
756 the new tp_richcompare slot in the type object. The cmp() function
757 and the C function PyObject_Compare() first try the new rich
758 comparison operators before trying the old 3-way comparison. There
759 is also a new C API PyObject_RichCompare() (which also falls back on
760 the old 3-way comparison, but does not constrain the outcome of the
761 rich comparison to a Boolean result).
762
763 The rich comparison function takes two objects (at least one of
764 which is guaranteed to have the type that provided the function) and
765 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
766 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
767 object, which may be NotImplemented (in which case the tp_compare
768 slot function is used as a fallback, if defined).
769
770 Classes can overload individual comparison operators by defining one
771 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000772 __ge__. There are no explicit "reflected argument" versions of
773 these; instead, __lt__ and __gt__ are each other's reflection,
774 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
775 reflection (similar at the C level). No other implications are
776 made; in particular, Python does not assume that == is the Boolean
777 inverse of !=, or that < is the Boolean inverse of >=. This makes
778 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000779
780 Classes or types that want to implement (in)equality tests but not
781 the ordering operators (i.e. unordered types) should implement ==
782 and !=, and raise an error for the ordering operators.
783
Guido van Rossuma88479f2001-01-18 14:28:08 +0000784 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000785 Boolean; e.g. a matrix type might want to return a matrix of bits
786 for A < B, giving elementwise comparisons. Such types should ensure
787 that any interpretation of their value in a Boolean context raises
788 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
789 at the C level) to always raise an exception.
790
Guido van Rossuma88479f2001-01-18 14:28:08 +0000791- Complex numbers use rich comparisons to define == and != but raise
792 an exception for <, <=, > and >=. Unfortunately, this also means
793 that cmp() of two complex numbers raises an exception when the two
794 numbers differ. Since it is not mathematically meaningful to compare
795 complex numbers except for equality, I hope that this doesn't break
796 too much code.
797
Tim Peters3389f192001-02-18 08:48:49 +0000798- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000799 not defined by the language, other than that it's arbitrary but
800 consistent (see the Reference Manual). An implementation detail changed
801 in 2.1a1 such that None now compares less than any other object. Code
802 relying on this new behavior (like code that relied on the previous
803 behavior) does so at its own risk.
804
Barry Warsaw573b5412001-01-15 20:43:18 +0000805- Functions and methods now support getting and setting arbitrarily
806 named attributes (PEP 232). Functions have a new __dict__
807 (a.k.a. func_dict) which hold the function attributes. Methods get
808 and set attributes on their underlying im_func. It is a TypeError
809 to set an attribute on a bound method.
810
Guido van Rossum051e3352001-01-15 19:11:10 +0000811- The xrange() object implementation has been improved so that
812 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
813 limitation that in this case len(xrange(sys.maxint)) can't be
814 calculated, but the common idiom "for i in xrange(sys.maxint)" will
815 work fine as long as the index i doesn't actually reach 2**31.
816 (Python uses regular ints for sequence and string indices; fixing
817 that is much more work.)
818
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000819- Two changes to from...import:
820
Guido van Rossumba381232001-02-03 15:06:40 +0000821 1) "from M import X" now works even if (after loading module M)
822 sys.modules['M'] is not a real module; it's basically a getattr()
823 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000824
825 2) "from M import *" now looks for M.__all__ to decide which names to
826 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
827 filters out names starting with '_' as before. Whether or not
828 __all__ exists, there's no restriction on the type of M.
829
Guido van Rossumf61f1662001-01-10 20:13:55 +0000830- File objects have a new method, xreadlines(). This is the fastest
831 way to iterate over all lines in a file:
832
833 for line in file.xreadlines():
834 ...do something to line...
835
836 See the xreadlines module (mentioned below) for how to do this for
837 other file-like objects.
838
839- Even if you don't use file.xreadlines(), you may expect a speedup on
840 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000841 quite a bit in platform-specific ways: on systems (like Linux) that
842 support flockfile(), getc_unlocked(), and funlockfile(), those are
843 used by default. On systems (like Windows) without getc_unlocked(),
844 a complicated (but still thread-safe) method using fgets() is used by
845 default.
846
Tim Petersd52269b2001-01-25 06:23:18 +0000847 You can force use of the fgets() method by #define'ing
848 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000849 getc_unlocked()).
850
Tim Petersd52269b2001-01-25 06:23:18 +0000851 You can force fgets() not to be used by #define'ing
852 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000853 test_bufio.py fails -- and let us know if it does!).
854
855- In addition, the fileinput module, while still slower than the other
856 methods on most platforms, has been sped up too, by using
857 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000858
859- Support for run-time warnings has been added, including a new
860 command line option (-W) to specify the disposition of warnings.
861 See the description of the warnings module below.
862
863- Extensive changes have been made to the coercion code. This mostly
864 affects extension modules (which can now implement mixed-type
865 numerical operators without having to use coercion), but
866 occasionally, in boundary cases the coercion semantics have changed
867 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000868 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000869 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000870 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000871
Guido van Rossumf98eda02001-01-17 15:54:45 +0000872- In connection with the coercion changes, a new built-in singleton
873 object, NotImplemented is defined. This can be returned for
874 operations that wish to indicate they are not implemented for a
875 particular combination of arguments. From C, this is
876 Py_NotImplemented.
877
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000878- The interpreter accepts now bytecode files on the command line even
879 if they do not have a .pyc or .pyo extension. On Linux, after executing
880
Martin v. Löwise214baa2001-02-04 22:37:56 +0000881import imp,sys,string
882magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
883reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
884open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000885
886 any byte code file can be used as an executable (i.e. as an argument
887 to execve(2)).
888
Tim Peters9940b802000-12-01 07:59:35 +0000889- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000890 character. In 1.6 and earlier, they never produced a sign,
891 and raised an error if the value of the long was too large
892 to fit in a Python int. In 2.0, they produced a sign if and
893 only if too large to fit in an int. This was inconsistent
894 across platforms (because the size of an int varies across
895 platforms), and inconsistent with hex() and oct(). Example:
896
897 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000898 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000899 'ffffffbe' # in 2.0 and before, on 32-bit machines
900 >>> hex(-0x42L)
901 '-0x42L' # in all versions of Python
902
Tim Peters9940b802000-12-01 07:59:35 +0000903 The behavior of %d formats for negative Python longs remains
904 the same as in 2.0 (although in 1.6 and before, they raised
905 an error if the long didn't fit in a Python int).
906
907 %u formats don't make sense for Python longs, but are allowed
908 and treated the same as %d in 2.1. In 2.0, a negative long
909 formatted via %u produced a sign if and only if too large to
910 fit in an int. In 1.6 and earlier, a negative long formatted
911 via %u raised an error if it was too big to fit in an int.
912
Guido van Rossum3661d392000-12-12 22:10:31 +0000913- Dictionary objects have an odd new method, popitem(). This removes
914 an arbitrary item from the dictionary and returns it (in the form of
915 a (key, value) pair). This can be useful for algorithms that use a
916 dictionary as a bag of "to do" items and repeatedly need to pick one
917 item. Such algorithms normally end up running in quadratic time;
918 using popitem() they can usually be made to run in linear time.
919
Tim Peters36cdad12000-12-29 02:06:45 +0000920Standard library
921
Thomas Woutersfe385252001-01-19 23:16:56 +0000922- In the time module, the time argument to the functions strftime,
923 localtime, gmtime, asctime and ctime is now optional, defaulting to
924 the current time (in the local timezone).
925
Guido van Rossumda91f222001-01-15 16:36:08 +0000926- The ftplib module now defaults to passive mode, which is deemed a
927 more useful default given that clients are often inside firewalls
928 these days. Note that this could break if ftplib is used to connect
929 to a *server* that is inside a firewall, from outside; this is
930 expected to be a very rare situation. To fix that, you can call
931 ftp.set_pasv(0).
932
Martin v. Löwis10a27872001-01-13 09:54:41 +0000933- The module site now treats .pth files not only for path configuration,
934 but also supports extensions to the initialization code: Lines starting
935 with import are executed.
936
Guido van Rossumf61f1662001-01-10 20:13:55 +0000937- There's a new module, warnings, which implements a mechanism for
938 issuing and filtering warnings. There are some new built-in
939 exceptions that serve as warning categories, and a new command line
940 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
941 turns warnings into errors). warnings.warn(message[, category])
942 issues a warning message; this can also be called from C as
943 PyErr_Warn(category, message).
944
945- A new module xreadlines was added. This exports a single factory
946 function, xreadlines(). The intention is that this code is the
947 absolutely fastest way to iterate over all lines in an open
948 file(-like) object:
949
950 import xreadlines
951 for line in xreadlines.xreadlines(file):
952 ...do something to line...
953
954 This is equivalent to the previous the speed record holder using
955 file.readlines(sizehint). Note that if file is a real file object
956 (as opposed to a file-like object), this is equivalent:
957
958 for line in file.xreadlines():
959 ...do something to line...
960
Tim Peters36cdad12000-12-29 02:06:45 +0000961- The bisect module has new functions bisect_left, insort_left,
962 bisect_right and insort_right. The old names bisect and insort
963 are now aliases for bisect_right and insort_right. XXX_right
964 and XXX_left methods differ in what happens when the new element
965 compares equal to one or more elements already in the list: the
966 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000967 right. Code that doesn't care where equal elements end up should
968 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000969
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000970- The new curses.panel module wraps the panel library that forms part
971 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
972
Guido van Rossumf61f1662001-01-10 20:13:55 +0000973- The SocketServer module now sets the allow_reuse_address flag by
974 default in the TCPServer class.
975
976- A new function, sys._getframe(), returns the stack frame pointer of
977 the caller. This is intended only as a building block for
978 higher-level mechanisms such as string interpolation.
979
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000980- The pyexpat module supports a number of new handlers, which are
981 available only in expat 1.2. If invocation of a callback fails, it
982 will report an additional frame in the traceback. Parser objects
983 participate now in garbage collection. If expat reports an unknown
984 encoding, pyexpat will try to use a Python codec; that works only
985 for single-byte charsets. The parser type objects is exposed as
986 XMLParserObject.
987
988- xml.dom now offers standard definitions for symbolic node type and
989 exception code constants, and a hierarchy of DOM exceptions. minidom
990 was adjusted to use them.
991
992- The conformance of xml.dom.minidom to the DOM specification was
993 improved. It detects a number of additional error cases; the
994 previous/next relationship works even when the tree is modified;
995 Node supports the normalize() method; NamedNodeMap, DocumentType and
996 DOMImplementation classes were added; Element supports the
997 hasAttribute and hasAttributeNS methods; and Text supports the splitText
998 method.
999
Guido van Rossumf61f1662001-01-10 20:13:55 +00001000Build issues
1001
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001002- For Unix (and Unix-compatible) builds, configuration and building of
1003 extension modules is now greatly automated. Rather than having to
1004 edit the Modules/Setup file to indicate which modules should be
1005 built and where their include files and libraries are, a
1006 distutils-based setup.py script now takes care of building most
1007 extension modules. All extension modules built this way are built
1008 as shared libraries. Only a few modules that must be linked
1009 statically are still listed in the Setup file; you won't need to
1010 edit their configuration.
1011
1012- Python should now build out of the box on Cygwin. If it doesn't,
1013 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001014
1015- Python now always uses its own (renamed) implementation of getopt()
1016 -- there's too much variation among C library getopt()
1017 implementations.
1018
1019- C++ compilers are better supported; the CXX macro is always set to a
1020 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001021
Tim Petersd92dfe02000-12-12 01:18:41 +00001022Windows changes
1023
1024- select module: By default under Windows, a select() call
1025 can specify no more than 64 sockets. Python now boosts
1026 this Microsoft default to 512. If you need even more than
1027 that, see the MS docs (you'll need to #define FD_SETSIZE
1028 and recompile Python from source).
1029
Guido van Rossumf61f1662001-01-10 20:13:55 +00001030- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1031 subdirectory is no more!
1032
Tim Petersa3a3a032000-11-30 05:22:44 +00001033
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001034What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001035=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001036
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001037Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001038changes are in the file HISTORY. If you are making the jump directly
1039from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1040HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001041
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001042Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1043the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1044http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001045
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001046--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001047
1048======================================================================
1049
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001050What's new in 2.0 (since release candidate 1)?
1051==============================================
1052
1053Standard library
1054
1055- The copy_reg module was modified to clarify its intended use: to
1056 register pickle support for extension types, not for classes.
1057 pickle() will raise a TypeError if it is passed a class.
1058
1059- Fixed a bug in gettext's "normalize and expand" code that prevented
1060 it from finding an existing .mo file.
1061
1062- Restored support for HTTP/0.9 servers in httplib.
1063
Tim Peters989b7b92000-10-16 20:24:53 +00001064- The math module was changed to stop raising OverflowError in case of
1065 underflow, and return 0 instead in underflow cases. Whether Python
1066 used to raise OverflowError in case of underflow was platform-
1067 dependent (it did when the platform math library set errno to ERANGE
1068 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001069
1070- Fixed a bug in StringIO that occurred when the file position was not
1071 at the end of the file and write() was called with enough data to
1072 extend past the end of the file.
1073
1074- Fixed a bug that caused Tkinter error messages to get lost on
1075 Windows. The bug was fixed by replacing direct use of
1076 interp->result with Tcl_GetStringResult(interp).
1077
1078- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1079 redirect response.
1080
1081- Several changes were made to distutils: Some debugging code was
1082 removed from util. Fixed the installer used when an external zip
1083 program (like WinZip) is not found; the source code for this
1084 installer is in Misc/distutils. check_lib() was modified to behave
1085 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1086 test for whether installed modules are on sys.path was changed to
1087 use both normcase() and normpath().
1088
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001089- Several minor bugs were fixed in the xml package (the minidom,
1090 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001091
1092- The regression test driver (regrtest.py) behavior when invoked with
1093 -l changed: It now reports a count of objects that are recognized as
1094 garbage but not freed by the garbage collector.
1095
Tim Peters989b7b92000-10-16 20:24:53 +00001096- The regression test for the math module was changed to test
1097 exceptional behavior when the test is run in verbose mode. Python
1098 cannot yet guarantee consistent exception behavior across platforms,
1099 so the exception part of test_math is run only in verbose mode, and
1100 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001101
1102Internals
1103
1104- PyOS_CheckStack() has been disabled on Win64, where it caused
1105 test_sre to fail.
1106
1107Build issues
1108
1109- Changed compiler flags, so that gcc is always invoked with -Wall and
1110 -Wstrict-prototypes. Users compiling Python with GCC should see
1111 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001112 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001113 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001114
Tim Petersa3a3a032000-11-30 05:22:44 +00001115- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001116
1117Tools and other miscellany
1118
1119- The compiler in Tools/compiler was updated to support the new
1120 language features introduced in 2.0: extended print statement, list
1121 comprehensions, and augmented assignments. The new compiler should
1122 also be backwards compatible with Python 1.5.2; the compiler will
1123 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001124 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001125
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001126What's new in 2.0 release candidate 1 (since beta 2)?
1127=====================================================
1128
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001129What is release candidate 1?
1130
1131We believe that release candidate 1 will fix all known bugs that we
1132intend to fix for the 2.0 final release. This release should be a bit
1133more stable than the previous betas. We would like to see even more
1134widespread testing before the final release, so we are producing this
1135release candidate. The final release will be exactly the same unless
1136any show-stopping (or brown bag) bugs are found by testers of the
1137release candidate.
1138
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001139All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001140to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001141
1142Core language, builtins, and interpreter
1143
1144- A bug that caused crashes when __coerce__ was used with augmented
1145 assignment, e.g. +=, was fixed.
1146
1147- Raise ZeroDivisionError when raising zero to a negative number,
1148 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1149 power operator and the result of math.pow(0.0, -2.0) will vary by
1150 platform. On Linux, it raises a ValueError.
1151
1152- A bug in Unicode string interpolation was fixed that occasionally
1153 caused errors with formats including "%%". For example, the
1154 following expression "%% %s" % u"abc" no longer raises a TypeError.
1155
1156- Compilation of deeply nested expressions raises MemoryError instead
1157 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1158
1159- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1160 rendering them useless. They are now written in binary mode again.
1161
1162Standard library
1163
1164- Keyword arguments are now accepted for most pattern and match object
1165 methods in SRE, the standard regular expression engine.
1166
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001167- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001168 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001169
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001170- Several bugs in the Unicode handling and error handling in _tkinter
1171 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001172
1173- Fix memory management errors in Merge() and Tkapp_Call() routines.
1174
1175- Several changes were made to cStringIO to make it compatible with
1176 the file-like object interface and with StringIO. If operations are
1177 performed on a closed object, an exception is raised. The truncate
1178 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001179 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001180
1181- There were many changes made to the linuxaudiodev module and its
1182 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001183 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001184
1185 Note that this module is named poorly, because it should work
1186 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001187 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001188
1189 The module now raises exceptions when errors occur instead of
1190 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1191 audio) and defines a getptr() method that calls the
1192 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1193
1194- The library_version attribute, introduced in an earlier beta, was
1195 removed because it can not be supported with early versions of the C
1196 readline library, which provides no way to determine the version at
1197 compile-time.
1198
1199- The binascii module is now enabled on Win64.
1200
Tim Peters46446d62000-10-09 21:19:31 +00001201- tokenize.py no longer suffers "recursion depth" errors when parsing
1202 programs with very long string literals.
1203
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001204Internals
1205
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001206- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001207 which is called when the interpreter starts up to determine where
1208 the standard library is installed. These vulnerabilities affect all
1209 previous versions of Python and can be exploited by setting very
1210 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1211 setuid Python script, although use of the wrapper in
1212 Misc/setuid-prog.c will eliminate the vulnerability.
1213
1214- Fixed garbage collection bugs in instance creation that were
1215 triggered when errors occurred during initialization. The solution,
1216 applied in cPickle and in PyInstance_New(), is to call
1217 PyObject_GC_Init() after the initialization of the object's
1218 container attributes is complete.
1219
1220- pyexpat adds definitions of PyModule_AddStringConstant and
1221 PyModule_AddObject if the Python version is less than 2.0, which
1222 provides compatibility with PyXML on Python 1.5.2.
1223
1224- If the platform has a bogus definition for LONG_BIT (the number of
1225 bits in a long), an error will be reported at compile time.
1226
1227- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1228 collection crashes and possibly other, unreported crashes.
1229
1230- Fixed a memory leak in _PyUnicode_Fini().
1231
1232Build issues
1233
1234- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001235 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001236 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001237
1238- The mmap.PAGESIZE constant is now initialized using sysconf when
1239 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1240
1241- The md5 file should now compile on all platforms.
1242
1243- The select module now compiles on platforms that do not define
1244 POLLRDNORM and related constants.
1245
1246- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001247 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001248
Jeremy Hylton10921202000-10-09 18:34:12 +00001249- BeOS: A number of changes were made to the build and installation
1250 process. ar-fake now operates on a directory of object files.
1251 dl_export.h is gone, and its macros now appear on the mwcc command
1252 line during build on PPC BeOS.
1253
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001254- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001255 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001256
1257- Cygwin: Support for shared libraries, Tkinter, and sockets.
1258
1259- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1260
1261Tools and other miscellany
1262
1263- Removed debugging prints from main used with freeze.
1264
Tim Peters46446d62000-10-09 21:19:31 +00001265- IDLE auto-indent no longer crashes when it encounters Unicode
1266 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001267
1268What's new in 2.0 beta 2 (since beta 1)?
1269========================================
1270
1271Core language, builtins, and interpreter
1272
Tim Peters482c0212000-09-26 06:33:09 +00001273- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001274 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001275
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001276- Add -h and -V command line options to print the usage message and
1277 Python version number and exit immediately.
1278
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001279- eval() and exec accept Unicode objects as code parameters.
1280
1281- getattr() and setattr() now also accept Unicode objects for the
1282 attribute name, which are converted to strings using the default
1283 encoding before lookup.
1284
1285- Multiplication on string and Unicode now does proper bounds
1286 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1287 string is too long."
1288
1289- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001290 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001291
Jeremy Hylton1b618592000-09-26 05:32:36 +00001292
1293Standard library and extensions
1294
Guido van Rossum5b08f132001-04-16 02:05:23 +00001295- socket module: the OpenSSL code now adds support for RAND_status()
1296 and EGD (Entropy Gathering Device).
1297
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001298- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001299 argument checking; it still takes no arguments.
1300
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001301- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001302
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001303- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001304
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001305- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001306
1307- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001308 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001309
1310- copy: Copy Unicode objects atomically.
1311
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001312- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001313
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001314- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001315
Fred Drake67233bc2000-09-26 16:40:27 +00001316- dbm: Add get() and setdefault() methods to dbm object. Add constant
1317 `library' to module that names the library used. Added doc strings
1318 and method names to error messages. Uses configure to determine
1319 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1320 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001321
1322- distutils: Update to version 0.9.3.
1323
1324- dl: Add several dl.RTLD_ constants.
1325
1326- fpectl: Now supported on FreeBSD.
1327
1328- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1329 found by the collector will be saved in gc.garbage. This is useful
1330 for debugging a program that creates reference cycles.
1331
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001332- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001333 of HTTP class. Do not close socket on zero-length response. Do not
1334 crash when server sends invalid content-length header.
1335
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001336- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001337
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001338- marshal: When reading a short, sign-extend on platforms where shorts
1339 are bigger than 16 bits. When reading a long, repair the unportable
1340 sign extension that was being done for 64-bit machines. (It assumed
1341 that signed right shift sign-extends.)
1342
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001343- operator: Add contains(), invert(), __invert__() as aliases for
1344 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001345
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001346- os: Add support for popen2() and popen3() on all platforms where
1347 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001348
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001349- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001350 clicking on a file in Explorer (or passing the file name to the
1351 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001352
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001353- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001354 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001355
1356- pickle: Now raises ValueError when an invalid pickle that contains
1357 a non-string repr where a string repr was expected. This behavior
1358 matches cPickle.
1359
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001360- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001361
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001362- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001363
1364- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001365 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001366 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001367
1368- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001369 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001370
1371- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001372 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001373 few cycles during startup since the first call to
1374 setdefaultencoding() will initialize the codec registry and the
1375 encodings package.
1376
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001377- socket: Support for size hint in readlines() method of object returned
1378 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001379
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001380- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001381 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001382 is followed by whitespace.
1383
Tim Petersa3a3a032000-11-30 05:22:44 +00001384- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001385
1386- struct: Check ranges for bytes and shorts.
1387
1388- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001389 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001390
1391- Tkinter: Image objects are now guaranteed to have unique ids. Set
1392 event.delta to zero if Tk version doesn't support mousewheel.
1393 Removed some debugging prints.
1394
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001395- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001396
Fred Drake67233bc2000-09-26 16:40:27 +00001397- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001398 which works around a bug in Norton AntiVirus 2000 that leads directly
1399 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001400
1401- xml: New version detection code allows PyXML to override standard
1402 XML package if PyXML version is greater than 0.6.1.
1403
Fred Drake64bb3802000-09-26 16:21:35 +00001404- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1405 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1406 tree only for nodes which are sufficiently interesting to a specific
1407 application. Does not provide the HTML-specific extensions. Still
1408 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001409
Fred Drake64bb3802000-09-26 16:21:35 +00001410- xml.sax: SAX 2 support for Python, including all the handler
1411 interfaces needed to process XML 1.0 compliant XML. Some
1412 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001413
Fred Drake64bb3802000-09-26 16:21:35 +00001414- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1415 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001416
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001417
Jeremy Hylton1b618592000-09-26 05:32:36 +00001418C API
1419
1420- Add three new convenience functions for module initialization --
1421 PyModule_AddObject(), PyModule_AddIntConstant(), and
1422 PyModule_AddStringConstant().
1423
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001424- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001425 removed and add #error to Python.h if NULL isn't defined after
1426 #include of stdio.h.
1427
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001428- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001429 backwards compatibility (at the source level) with old extensions.
1430
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001431- A wrapper API was added for signal() and sigaction(). Instead of
1432 either function, always use PyOS_getsig() to get a signal handler
1433 and PyOS_setsig() to set one. A new convenience typedef
1434 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001435
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001436- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001437 internal data buffer and size of a string object -- or the default
1438 encoded version of a Unicode object.
1439
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001440- PyString_Size() and PyString_AsString() accept Unicode objects.
1441
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001442- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001443 exists). INT_MAX and LONG_MAX will always be defined, even if
1444 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001445
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001446- PyFloat_FromString takes a second argument, pend, that was
1447 effectively useless. It is now officially useless but preserved for
1448 backwards compatibility. If the pend argument is not NULL, *pend is
1449 set to NULL.
1450
1451- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1452 for the attribute name. See note on getattr() above.
1453
1454- A few bug fixes to argument processing for Unicode.
1455 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1456 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1457 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001458 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001459
1460- Py_BuildValue accepts B format (for bgen-generated code).
1461
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001462
Jeremy Hylton1b618592000-09-26 05:32:36 +00001463Internals
1464
1465- On Unix, fix code for finding Python installation directory so that
1466 it works when argv[0] is a relative path.
1467
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001468- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001469 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001470 rather than by generating a copy of the object.
1471
Tim Peters482c0212000-09-26 06:33:09 +00001472- Several of the internal Unicode tables are much smaller now, and
1473 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001474
Jeremy Hylton97693b02000-09-26 17:42:51 +00001475- In the garbage collector: Fixed bug in collection of tuples. Fixed
1476 bug that caused some instances to be removed from the container set
1477 while they were still live. Fixed parsing in gc.set_debug() for
1478 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001479
1480- Fixed refcount problem in instance deallocation that only occurred
1481 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1482
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001483- On Windows, getpythonregpath is now protected against null data in
1484 registry key.
1485
1486- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001487 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001488
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001489
Jeremy Hylton1b618592000-09-26 05:32:36 +00001490Build and platform-specific issues
1491
1492- Better support of GNU Pth via --with-pth configure option.
1493
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001494- Python/C API now properly exposed to dynamically-loaded extension
1495 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001496
1497- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1498 Don't define MS_SYNC to be zero when it is undefined. Added missing
1499 prototypes in posixmodule.c.
1500
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001501- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001502 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001503
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001504- Fix largefile support on older NetBSD systems and OpenBSD by adding
1505 define for TELL64.
1506
1507
1508Tools and other miscellany
1509
1510- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1511
1512- freeze: The modulefinder now works with 2.0 opcodes.
1513
Tim Petersa3a3a032000-11-30 05:22:44 +00001514- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001515 Move hackery of sys.argv until after the Tk instance has been
1516 created, which allows the application-specific Tkinter
1517 initialization to be executed if present; also pass an explicit
1518 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001519
Jeremy Hylton1b618592000-09-26 05:32:36 +00001520
1521What's new in 2.0 beta 1?
1522=========================
1523
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001524Source Incompatibilities
1525------------------------
1526
1527None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1528such as single-argument append(), connect() and bind(), and changes to
1529str(long) and repr(float).
1530
1531
1532Binary Incompatibilities
1533------------------------
1534
1535- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1536with Python 2.0; these extensions will have to be rebuilt for Python
15372.0.
1538
1539- On Windows, attempting to import a third party extension built for
1540Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1541can do about this. Check your PYTHONPATH environment variable!
1542
1543- Python bytecode files (*.pyc and *.pyo) are not compatible between
1544releases.
1545
1546
1547Overview of Changes Since 1.6
1548-----------------------------
1549
1550There are many new modules (including brand new XML support through
1551the xml package, and i18n support through the gettext module); a list
1552of all new modules is included below. Lots of bugs have been fixed.
1553
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001554The process for making major new changes to the language has changed
1555since Python 1.6. Enhancements must now be documented by a Python
1556Enhancement Proposal (PEP) before they can be accepted.
1557
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001558There are several important syntax enhancements, described in more
1559detail below:
1560
1561 - Augmented assignment, e.g. x += 1
1562
1563 - List comprehensions, e.g. [x**2 for x in range(10)]
1564
1565 - Extended import statement, e.g. import Module as Name
1566
1567 - Extended print statement, e.g. print >> file, "Hello"
1568
1569Other important changes:
1570
1571 - Optional collection of cyclical garbage
1572
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001573Python Enhancement Proposal (PEP)
1574---------------------------------
1575
1576PEP stands for Python Enhancement Proposal. A PEP is a design
1577document providing information to the Python community, or describing
1578a new feature for Python. The PEP should provide a concise technical
1579specification of the feature and a rationale for the feature.
1580
1581We intend PEPs to be the primary mechanisms for proposing new
1582features, for collecting community input on an issue, and for
1583documenting the design decisions that have gone into Python. The PEP
1584author is responsible for building consensus within the community and
1585documenting dissenting opinions.
1586
1587The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001588
1589Augmented Assignment
1590--------------------
1591
1592This must have been the most-requested feature of the past years!
1593Eleven new assignment operators were added:
1594
Guido van Rossume905e952000-09-05 12:42:46 +00001595 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001596
1597For example,
1598
1599 A += B
1600
1601is similar to
1602
1603 A = A + B
1604
1605except that A is evaluated only once (relevant when A is something
1606like dict[index].attr).
1607
1608However, if A is a mutable object, A may be modified in place. Thus,
1609if A is a number or a string, A += B has the same effect as A = A+B
1610(except A is only evaluated once); but if a is a list, A += B has the
1611same effect as A.extend(B)!
1612
1613Classes and built-in object types can override the new operators in
1614order to implement the in-place behavior; the not-in-place behavior is
1615used automatically as a fallback when an object doesn't implement the
1616in-place behavior. For classes, the method name is derived from the
1617method name for the corresponding not-in-place operator by inserting
1618an 'i' in front of the name, e.g. __iadd__ implements in-place
1619__add__.
1620
1621Augmented assignment was implemented by Thomas Wouters.
1622
1623
1624List Comprehensions
1625-------------------
1626
1627This is a flexible new notation for lists whose elements are computed
1628from another list (or lists). The simplest form is:
1629
1630 [<expression> for <variable> in <sequence>]
1631
Guido van Rossum56db0952000-09-06 23:34:25 +00001632For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001633This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001634
1635You can also add a condition:
1636
1637 [<expression> for <variable> in <sequence> if <condition>]
1638
1639For example, [w for w in words if w == w.lower()] would yield the list
1640of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001641than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001642
1643You can also have nested for loops and more than one 'if' clause. For
1644example, here's a function that flattens a sequence of sequences::
1645
1646 def flatten(seq):
1647 return [x for subseq in seq for x in subseq]
1648
1649 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1650
1651This prints
1652
1653 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1654
1655List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001656Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001657
1658
1659Extended Import Statement
1660-------------------------
1661
1662Many people have asked for a way to import a module under a different
1663name. This can be accomplished like this:
1664
1665 import foo
1666 bar = foo
1667 del foo
1668
1669but this common idiom gets old quickly. A simple extension of the
1670import statement now allows this to be written as follows:
1671
1672 import foo as bar
1673
1674There's also a variant for 'from ... import':
1675
1676 from foo import bar as spam
1677
1678This also works with packages; e.g. you can write this:
1679
1680 import test.regrtest as regrtest
1681
1682Note that 'as' is not a new keyword -- it is recognized only in this
1683context (this is only possible because the syntax for the import
1684statement doesn't involve expressions).
1685
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001686Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001687
1688
1689Extended Print Statement
1690------------------------
1691
1692Easily the most controversial new feature, this extension to the print
1693statement adds an option to make the output go to a different file
1694than the default sys.stdout.
1695
1696For example, to write an error message to sys.stderr, you can now
1697write:
1698
1699 print >> sys.stderr, "Error: bad dog!"
1700
1701As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001702evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001703
1704 print >> None, "Hello world"
1705
1706is equivalent to
1707
1708 print "Hello world"
1709
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001710Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001711
1712
1713Optional Collection of Cyclical Garbage
1714---------------------------------------
1715
1716Python is now equipped with a garbage collector that can hunt down
1717cyclical references between Python objects. It's no replacement for
1718reference counting; in fact, it depends on the reference counts being
1719correct, and decides that a set of objects belong to a cycle if all
1720their reference counts can be accounted for from their references to
1721each other. This devious scheme was first proposed by Eric Tiedemann,
1722and brought to implementation by Neil Schemenauer.
1723
1724There's a module "gc" that lets you control some parameters of the
1725garbage collection. There's also an option to the configure script
1726that lets you enable or disable the garbage collection. In 2.0b1,
1727it's on by default, so that we (hopefully) can collect decent user
1728experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001729performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001730off by default in the final 2.0 release.
1731
1732
1733Smaller Changes
1734---------------
1735
1736A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1737map(None, seq1, seq2, ...) when the sequences have the same length;
1738i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1739the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001740zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001741
1742sys.version_info is a tuple (major, minor, micro, level, serial).
1743
1744Dictionaries have an odd new method, setdefault(key, default).
1745dict.setdefault(key, default) returns dict[key] if it exists; if not,
1746it sets dict[key] to default and returns that value. Thus:
1747
1748 dict.setdefault(key, []).append(item)
1749
1750does the same work as this common idiom:
1751
1752 if not dict.has_key(key):
1753 dict[key] = []
1754 dict[key].append(item)
1755
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001756There are two new variants of SyntaxError that are raised for
1757indentation-related errors: IndentationError and TabError.
1758
1759Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1760escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001761
1762The limits on the size of expressions and file in Python source code
1763have been raised from 2**16 to 2**32. Previous versions of Python
1764were limited because the maximum argument size the Python VM accepted
1765was 2**16. This limited the size of object constructor expressions,
1766e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1767limit was raised thanks to a patch by Charles Waldman that effectively
1768fixes the problem. It is now much more likely that you will be
1769limited by available memory than by an arbitrary limit in Python.
1770
1771The interpreter's maximum recursion depth can be modified by Python
1772programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1773limit is the maximum number of recursive calls that can be made by
1774Python code. The limit exists to prevent infinite recursion from
1775overflowing the C stack and causing a core dump. The default value is
17761000. The maximum safe value for a particular platform can be found
1777by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001778
1779New Modules and Packages
1780------------------------
1781
1782atexit - for registering functions to be called when Python exits.
1783
1784imputil - Greg Stein's alternative API for writing custom import
1785hooks.
1786
1787pyexpat - an interface to the Expat XML parser, contributed by Paul
1788Prescod.
1789
1790xml - a new package with XML support code organized (so far) in three
1791subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1792would fill a volume. There's a special feature whereby a
1793user-installed package named _xmlplus overrides the standard
1794xmlpackage; this is intended to give the XML SIG a hook to distribute
1795backwards-compatible updates to the standard xml package.
1796
1797webbrowser - a platform-independent API to launch a web browser.
1798
1799
Guido van Rossume905e952000-09-05 12:42:46 +00001800Changed Modules
1801---------------
1802
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001803array -- new methods for array objects: count, extend, index, pop, and
1804remove
1805
1806binascii -- new functions b2a_hex and a2b_hex that convert between
1807binary data and its hex representation
1808
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001809calendar -- Many new functions that support features including control
1810over which day of the week is the first day, returning strings instead
1811of printing them. Also new symbolic constants for days of week,
1812e.g. MONDAY, ..., SUNDAY.
1813
1814cgi -- FieldStorage objects have a getvalue method that works like a
1815dictionary's get method and returns the value attribute of the object.
1816
1817ConfigParser -- The parser object has new methods has_option,
1818remove_section, remove_option, set, and write. They allow the module
1819to be used for writing config files as well as reading them.
1820
1821ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001822optionally support the RFC 959 REST command.
1823
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001824gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001825
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001826httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1827the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001828
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001829locale -- implement getdefaultlocale for Win32 and Macintosh
1830
1831marshal -- no longer dumps core when marshaling deeply nested or
1832recursive data structures
1833
1834os -- new functions isatty, seteuid, setegid, setreuid, setregid
1835
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001836os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1837support under Unix.
1838
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001839os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001840
1841os.path -- fix semantics of os.path.commonprefix
1842
1843smtplib -- support for sending very long messages
1844
1845socket -- new function getfqdn()
1846
1847readline -- new functions to read, write and truncate history files.
1848The readline section of the library reference manual contains an
1849example.
1850
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001851select -- add interface to poll system call
1852
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001853shutil -- new copyfileobj function
1854
1855SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1856HTTP server.
1857
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001858Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001859
1860urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001861e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001862
1863whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001864
1865
1866Obsolete Modules
1867----------------
1868
1869None. However note that 1.6 made a whole slew of modules obsolete:
1870stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1871poly, zmod, strop, util, whatsound.
1872
1873
1874Changed, New, Obsolete Tools
1875----------------------------
1876
Tim Peters8b092332000-09-05 20:15:25 +00001877None.
Guido van Rossume905e952000-09-05 12:42:46 +00001878
1879
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001880C-level Changes
1881---------------
1882
1883Several cleanup jobs were carried out throughout the source code.
1884
1885All C code was converted to ANSI C; we got rid of all uses of the
1886Py_PROTO() macro, which makes the header files a lot more readable.
1887
1888Most of the portability hacks were moved to a new header file,
1889pyport.h; several other new header files were added and some old
1890header files were removed, in an attempt to create a more rational set
1891of header files. (Few of these ever need to be included explicitly;
1892they are all included by Python.h.)
1893
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001894Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001895and Win64, especially for the new Intel Itanium processor. Mick also
1896added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001897
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001898The C APIs to return an object's size have been update to consistently
1899use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1900previous versions, the abstract interfaces used PyXXX_Length and the
1901concrete interfaces used PyXXX_Size. The old names,
1902e.g. PyObject_Length, are still available for backwards compatibility
1903at the API level, but are deprecated.
1904
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001905The PyOS_CheckStack function has been implemented on Windows by
1906Fredrik Lundh. It prevents Python from failing with a stack overflow
1907on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001908
1909The GC changes resulted in creation of two new slots on object,
1910tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001911the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001912
1913The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001914C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001915
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001916PyErr_Format has been updated to automatically calculate the size of
1917the buffer needed to hold the formatted result string. This change
1918prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001919
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001920New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001921
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001922PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1923that are the same as their non-Ex counterparts except they take an
1924extra flag argument that tells them to close the file when done.
1925
1926XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001927
Tim Peters8b092332000-09-05 20:15:25 +00001928
1929Windows Changes
1930---------------
1931
1932New popen2/popen3/peopen4 in os module (see Changed Modules above).
1933
1934os.popen is much more usable on Windows 95 and 98. See Microsoft
1935Knowledge Base article Q150956. The Win9x workaround described there
1936is implemented by the new w9xpopen.exe helper in the root of your
1937Python installation. Note that Python uses this internally; it is not
1938a standalone program.
1939
1940Administrator privileges are no longer required to install Python
1941on Windows NT or Windows 2000. If you have administrator privileges,
1942Python's registry info will be written under HKEY_LOCAL_MACHINE.
1943Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001944under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001945uses of Python, but will prevent some advanced uses from working
1946(for example, running a Python script as an NT service, or possibly
1947from CGI).
1948
1949[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1950installer; instead, it installs the needed Tcl/Tk files directly in the
1951Python directory. If you already have a Tcl/Tk installation, this
1952wastes some disk space (about 4 Megs) but avoids problems with
1953conflicting Tcl/Tk installations, and makes it much easier for Python
1954to ensure that Tcl/Tk can find all its files.
1955
1956[This was new in 1.6] The Windows installer now installs by default in
1957\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1958
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001959
1960Updates to the changes between 1.5.2 and 1.6
1961--------------------------------------------
1962
1963The 1.6 NEWS file can't be changed after the release is done, so here
1964is some late-breaking news:
1965
1966New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1967and changes to getlocale() and setlocale().
1968
1969The new module is now enabled per default.
1970
1971It is not true that the encodings codecs cannot be used for normal
1972strings: the string.encode() (which is also present on 8-bit strings
1973!) allows using them for 8-bit strings too, e.g. to convert files from
1974cp1252 (Windows) to latin-1 or vice-versa.
1975
1976Japanese codecs are available from Tamito KAJIYAMA:
1977http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1978
1979
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001980======================================================================