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Tim Petersf553f892001-05-01 20:45:31 +00001What's New in Python 2.2a0?
2===========================
3
4Core
Tim Petersa814db52001-05-14 07:05:58 +00005
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00006- The UTF-16 codec was modified to be more RFC compliant. It will now
7 only remove BOM characters at the start of the string and then
8 only if running in native mode (UTF-16-LE and -BE won't remove a
9 leading BMO character).
10
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000011- Strings now have a new method .decode() to complement the already
12 existing .encode() method. These two methods provide direct access
13 to the corresponding decoders and encoders of the registered codecs.
14
15 To enhance the usability of the .encode() method, the special
16 casing of Unicode object return values was dropped (Unicode objects
17 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +000018
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000019 Both methods will now return whatever the codec in charge of the
20 requested encoding returns as object, e.g. Unicode codecs will
21 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
22 will return u"äöü"). This enables codec writer to create codecs
23 for various simple to use conversions.
24
25 New codecs were added to demonstrate these new features (the .encode()
26 and .decode() columns indicate the type of the returned objects):
27
28 Name | .encode() | .decode() | Description
29 ----------------------------------------------------------------------
30 uu | string | string | UU codec (e.g. for email)
31 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +000032 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000033 zlib | string | string | zlib compression
34 hex | string | string | 2-byte hex codec
35 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
36
Mark Hammond2a0af792001-05-14 03:09:36 +000037- Some operating systems now support the concept of a default Unicode
38 encoding for file system operations. Notably, Windows supports 'mbcs'
39 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +000040 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000041 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000042
43 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000044 functions that return filenames (such as os.listdir()) to return Python
45 string objects pre-encoded using the default file system encoding for
46 the platform. As this encoding is likely to be different from Python's
47 default encoding, converting this name to a Unicode object before passing
48 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000049 would attempt to use its default encoding (generally ASCII) rather than
50 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000051
Tim Petersa814db52001-05-14 07:05:58 +000052 In general, this change simply removes surprises when working with
53 Unicode and the file system, making these operations work as you expect,
54 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +000055 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +000056
Tim Peters61dff2b2001-05-08 15:43:37 +000057- Float (and complex) literals in source code were evaluated to full
58 precision only when running from a .py file; the same code loaded from a
59 .pyc (or .pyo) file could suffer numeric differences starting at about the
60 12th significant decimal digit. For example, on a machine with IEEE-754
61 floating arithmetic,
62
63 x = 9007199254740992.0
64 print long(x)
65
66 printed 9007199254740992 if run directly from .py, but 9007199254740000
67 if from a compiled (.pyc or .pyo) file. This was due to marshal using
68 str(float) instead of repr(float) when building code objects. marshal
69 now uses repr(float) instead, which should reproduce floats to full
70 machine precision (assuming the platform C float<->string I/O conversion
71 functions are of good quality).
72
73 This may cause floating-point results to change in some cases, and
74 usually for the better, but may also cause numerically unstable
75 algorithms to break.
76
Tim Peters2f228e72001-05-13 00:19:31 +000077- The implementation of dicts suffers fewer collisions, which has speed
78 benefits. However, the order in which dict entries appear in dict.keys(),
79 dict.values() and dict.items() may differ from previous releases for a
80 given dict. Nothing is defined about this order, so no program should
81 rely on it. Nevertheless, it's easy to write test cases that rely on the
82 order by accident, typically because of printing the str() or repr() of a
83 dict to an "expected results" file. See Lib/test/test_support.py's new
84 sortdict(dict) function for a simple way to display a dict in sorted
85 order.
86
Tim Peters7a3bfc32001-06-12 01:22:22 +000087- Many other small changes to dicts were made, resulting in faster
88 operation along the most common code paths.
89
Guido van Rossum10315822001-05-01 20:54:30 +000090- Dictionary objects now support the "in" operator: "x in dict" means
91 the same as dict.has_key(x).
92
93- Iterators were added; this is a generalized way of providing values
94 to a for loop. See PEP 234. There's a new built-in function iter()
95 to return an iterator. There's a new protocol to get the next value
96 from an iterator using the next() method (in Python) or the
97 tp_iternext slot (in C). There's a new protocol to get iterators
98 using the __iter__() method (in Python) or the tp_iter slot (in C).
99 Iterating (i.e. a for loop) over a dictionary generates its keys.
100 Iterating over a file generates its lines.
101
Tim Petersf553f892001-05-01 20:45:31 +0000102- The following functions were generalized to work nicely with iterator
103 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000104 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000105 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
106 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000107 join() method of strings
108 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000109 'x in y' and 'x not in y' (PySequence_Contains() in C API)
110 operator.countOf() (PySequence_Count() in C API)
Tim Peters75f8e352001-05-05 11:33:43 +0000111
Tim Petersd85e1022001-05-11 21:51:48 +0000112- Accessing module attributes is significantly faster (for example,
113 random.random or os.path or yourPythonModule.yourAttribute).
114
Tim Peterse63415e2001-05-08 04:38:29 +0000115- Comparing dictionary objects via == and != is faster, and now works even
116 if the keys and values don't support comparisons other than ==.
117
Tim Peters95bf9392001-05-10 08:32:44 +0000118- Comparing dictionaries in ways other than == and != is slower: there were
119 insecurities in the dict comparison implementation that could cause Python
120 to crash if the element comparison routines for the dict keys and/or
121 values mutated the dicts. Making the code bulletproof slowed it down.
122
Tim Peterseb28ef22001-06-02 05:27:19 +0000123- Collisions in dicts are resolved via a new approach, which can help
124 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000125 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000126 faster now. Thanks to Christian Tismer for pointing out the cause and
127 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000128
Tim Petersa814db52001-05-14 07:05:58 +0000129Library
130
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000131- A new function fnmatch.filter to filter lists of file names was added.
132
Barry Warsawffd674d2001-05-22 16:00:10 +0000133- calendar.py uses month and day names based on the current locale.
134
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000135- strop is now *really* obsolete (this was announced before with 1.6),
136 and issues DeprecationWarning when used (except for the four items
137 that are still imported into string.py).
138
Tim Petersa814db52001-05-14 07:05:58 +0000139- Cookie.py now sorts key+value pairs by key in output strings.
140
141- pprint.isrecursive(object) didn't correctly identify recursive objects.
142 Now it does.
143
Tim Peters95b3f782001-05-14 18:39:41 +0000144- pprint functions now much faster for large containers (tuple, list, dict).
145
Tim Peters7b9542a2001-06-10 23:40:19 +0000146- New 'q' and 'Q' format codes in the struct module, corresponding to C
147 types "long long" and "unsigned long long" (on Windows, __int64). In
148 native mode, these can be used only when the platform C compiler supports
149 these types (when HAVE_LONG_LONG is #define'd by the Python config
150 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000151 In standard mode, 'q' and 'Q' are supported on all platforms, and are
152 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000153
Guido van Rossum83213cc2001-06-12 16:48:52 +0000154- The site module installs a new built-in function 'help' that invokes
155 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
156 it displays a message reminding the user to use 'help()' or
157 'help(object)'.
158
Tim Petersa814db52001-05-14 07:05:58 +0000159Tests
160
161- New test_mutants.py runs dict comparisons where the key and value
162 comparison operators mutute the dicts randomly during comparison. This
163 rapidly causes Python to crash under earlier releases (not for the faint
164 of heart: it can also cause Win9x to freeze or reboot!).
165
166- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000167 pprint.isreadable() return sensible results. Also verifies that simple
168 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000169
Tim Peters58e0a8c2001-05-14 22:32:33 +0000170New platforms
171
172- Python should compile and run out of the box using the Borland C
173 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000174
Tim Peters4324aa32001-05-28 22:30:08 +0000175C API
176
177- Removed the unused last_is_sticky argument from the internal
178 _PyTuple_Resize(). If this affects you, you were cheating.
179
180
Guido van Rossumffe13be2001-04-16 18:46:45 +0000181What's New in Python 2.1 (final)?
182=================================
183
184We only changed a few things since the last release candidate, all in
185Python library code:
186
187- A bug in the locale module was fixed that affected locales which
188 define no grouping for numeric formatting.
189
190- A few bugs in the weakref module's implementations of weak
191 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
192 and the test suite was updated to check for these bugs.
193
194- An old bug in the os.path.walk() function (introduced in Python
195 2.0!) was fixed: a non-existent file would cause an exception
196 instead of being ignored.
197
198- Fixed a few bugs in the new symtable module found by Neil Norwitz's
199 PyChecker.
200
201
Guido van Rossum5b08f132001-04-16 02:05:23 +0000202What's New in Python 2.1c2?
203===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000204
Guido van Rossum5b08f132001-04-16 02:05:23 +0000205A flurry of small changes, and one showstopper fixed in the nick of
206time made it necessary to release another release candidate. The list
207here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000208
Guido van Rossum5b08f132001-04-16 02:05:23 +0000209Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000210
Guido van Rossum5b08f132001-04-16 02:05:23 +0000211- Tim discovered a nasty bug in the dictionary code, caused by
212 PyDict_Next() calling dict_resize(), and the GC code's use of
213 PyDict_Next() violating an assumption in dict_items(). This was
214 fixed with considerable amounts of band-aid, but the net effect is a
215 saner and more robust implementation.
216
217- Made a bunch of symbols static that were accidentally global.
218
219Build and Ports
220
221- The setup.py script didn't check for a new enough version of zlib
222 (1.1.3 is needed). Now it does.
223
224- Changed "make clean" target to also remove shared libraries.
225
226- Added a more general warning about the SGI Irix optimizer to README.
227
228Library
229
230- Fix a bug in urllib.basejoin("http://host", "../file.html") which
231 omitted the slash between host and file.html.
232
233- The mailbox module's _Mailbox class contained a completely broken
234 and undocumented seek() method. Ripped it out.
235
236- Fixed a bunch of typos in various library modules (urllib2, smtpd,
237 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
238
239- Fixed a few last-minute bugs in unittest.
240
241Extensions
242
243- Reverted the patch to the OpenSSL code in socketmodule.c to support
244 RAND_status() and the EGD, and the subsequent patch that tried to
245 fix it for pre-0.9.5 versions; the problem with the patch is that on
246 some systems it issues a warning whenever socket is imported, and
247 that's unacceptable.
248
249Tests
250
251- Fixed the pickle tests to work with "import test.test_pickle".
252
253- Tweaked test_locale.py to actually run the test Windows.
254
255- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
256 not "wb" (which is not a valid mode at all).
257
258- Fix pstats browser crashes. Import readline if it exists to make
259 the user interface nicer.
260
261- Add "import thread" to the top of test modules that import the
262 threading module (test_asynchat and test_threadedtempfile). This
263 prevents test failures caused by a broken threading module resulting
264 from a previously caught failed import.
265
266- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
267 needed on some platforms (e.g. Solaris 8) when the tests are run
268 twice in succession.
269
270- Skip rather than fail test_sunaudiodev if no audio device is found.
271
272
273What's New in Python 2.1c1?
274===========================
275
276This list was significantly updated when 2.1c2 was released; the 2.1c1
277release didn't mention most changes that were actually part of 2.1c1:
278
279Legal
280
281- Copyright was assigned to the Python Software Foundation (PSF) and a
282 PSF license (very similar to the CNRI license) was added.
283
284- The CNRI copyright notice was updated to include 2001.
285
286Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000287
Guido van Rossumc9932722001-04-12 02:31:27 +0000288- After a public outcry, assignment to __debug__ is no longer illegal;
289 instead, a warning is issued. It will become illegal in 2.2.
290
Guido van Rossum5b08f132001-04-16 02:05:23 +0000291- Fixed a core dump with "%#x" % 0, and changed the semantics so that
292 "%#x" now always prepends "0x", even if the value is zero.
293
294- Fixed some nits in the bytecode compiler.
295
296- Fixed core dumps when calling certain kinds of non-functions.
297
298- Fixed various core dumps caused by reference count bugs.
299
300Build and Ports
301
302- Use INSTALL_SCRIPT to install script files.
303
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000304- New port: SCO Unixware 7, by Billy G. Allie.
305
Guido van Rossum5b08f132001-04-16 02:05:23 +0000306- Updated RISCOS port.
307
308- Updated BeOS port and notes.
309
310- Various other porting problems resolved.
311
312Library
313
314- The TERMIOS and SOCKET modules are now truly obsolete and
315 unnecessary. Their symbols are incorporated in the termios and
316 socket modules.
317
318- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
319 better tests for pickling.
320
321- threading: make Condition.wait() robust against KeyboardInterrupt.
322
323- zipfile: add support to zipfile to support opening an archive
324 represented by an open file rather than a file name. Fix bug where
325 the archive was not properly closed. Fixed a bug in this bugfix
326 where flush() was called for a read-only file.
327
328- imputil: added an uninstall() method to the ImportManager.
329
330- Canvas: fixed bugs in lower() and tkraise() methods.
331
332- SocketServer: API change (added overridable close_request() method)
333 so that the TCP server can explicitly close the request.
334
335- pstats: Eric Raymond added a simple interactive statistics browser,
336 invoked when the module is run as a script.
337
338- locale: fixed a problem in format().
339
340- webbrowser: made it work when the BROWSER environment variable has a
341 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
342 KDE 2. Fixed some other nits.
343
344- unittest: changes to allow using a different exception than
345 AssertionError, and added a few more function aliases. Some other
346 small changes.
347
348- urllib, urllib2: fixed redirect problems and a coupleof other nits.
349
350- asynchat: fixed a critical bug in asynchat that slipped through the
351 2.1b2 release. Fixed another rare bug.
352
353- Fix some unqualified except: clauses (always a bad code example).
354
355XML
356
357- pyexpat: new API get_version_string().
358
359- Fixed some minidom bugs.
360
361Extensions
362
363- Fixed a core dump in _weakref. Removed the weakref.mapping()
364 function (it adds nothing to the API).
365
366- Rationalized the use of header files in the readline module, to make
367 it compile (albeit with some warnings) with the very recent readline
368 4.2, without breaking for earlier versions.
369
370- Hopefully fixed a buffering problem in linuxaudiodev.
371
372- Attempted a fix to make the OpenSSL support in the socket module
373 work again with pre-0.9.5 versions of OpenSSL.
374
375Tests
376
377- Added a test case for asynchat and asyncore.
378
379- Removed coupling between tests where one test failing could break
380 another.
381
382Tools
383
384- Ping added an interactive help browser to pydoc, fixed some nits
385 in the rest of the pydoc code, and added some features to his
386 inspect module.
387
388- An updated python-mode.el version 4.1 which integrates Ken
389 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
390 much nicer in XEmacs and Emacs. When stepping through your program
391 with pdb, in either the shell window or the *Python* window, the
392 source file and line will be tracked by an arrow. Very cool!
393
394- IDLE: syntax warnings in interactive mode are changed into errors.
395
396- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000397 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000398
399- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000400
Barry Warsaw11e89c72001-04-11 20:37:57 +0000401
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000402What's New in Python 2.1 beta 2?
403================================
404
Guido van Rossum053ae352001-03-22 14:17:21 +0000405(Unlisted are many fixed bugs, more documentation, etc.)
406
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000407Core language, builtins, and interpreter
408
Guido van Rossum053ae352001-03-22 14:17:21 +0000409- The nested scopes work (enabled by "from __future__ import
410 nested_scopes") is completed; in particular, the future now extends
411 into code executed through exec, eval() and execfile(), and into the
412 interactive interpreter.
413
414- When calling a base class method (e.g. BaseClass.__init__(self)),
415 this is now allowed even if self is not strictly spoken a class
416 instance (e.g. when using metaclasses or the Don Beaudry hook).
417
418- Slice objects are now comparable but not hashable; this prevents
419 dict[:] from being accepted but meaningless.
420
421- Complex division is now calculated using less braindead algorithms.
422 This doesn't change semantics except it's more likely to give useful
423 results in extreme cases. Complex repr() now uses full precision
424 like float repr().
425
426- sgmllib.py now calls handle_decl() for simple <!...> declarations.
427
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000428- It is illegal to assign to the name __debug__, which is set when the
429 interpreter starts. It is effectively a compile-time constant.
430
431- A warning will be issued if a global statement for a variable
432 follows a use or assignment of that variable.
433
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000434Standard library
435
Guido van Rossum053ae352001-03-22 14:17:21 +0000436- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
437 inspired by JUnit), is now part of the standard library. You now
438 have a choice of two testing frameworks: unittest requires you to
439 write testcases as separate code, doctest gathers them from
440 docstrings. Both approaches have their advantages and
441 disadvantages.
442
443- A new module Tix was added, which wraps the Tix extension library
444 for Tk. With that module, it is not necessary to statically link
445 Tix with _tkinter, since Tix will be loaded with Tcl's "package
446 require" command. See Demo/tix/.
447
448- tzparse.py is now obsolete.
449
450- In gzip.py, the seek() and tell() methods are removed -- they were
451 non-functional anyway, and it's better if callers can test for their
452 existence with hasattr().
453
454Python/C API
455
456- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
457 that's already in the dictionary during a PyDict_Next() iteration.
458 This used to fail occasionally when a dictionary resize operation
459 could be triggered that would rehash all the keys. All other
460 modifications to the dictionary are still off-limits during a
461 PyDict_Next() iteration!
462
463- New extended APIs related to passing compiler variables around.
464
465- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
466 implement isinstance() and issubclass().
467
468- Py_BuildValue() now has a "D" conversion to create a Python complex
469 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000470
Fred Drake4e262a92001-03-22 18:26:47 +0000471- Extensions types which support weak references must now set the
472 field allocated for the weak reference machinery to NULL themselves;
473 this is done to avoid the cost of checking each object for having a
474 weakly referencable type in PyObject_INIT(), since most types are
475 not weakly referencable.
476
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000477- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
478 free variables and cell variables to and from the frame's f_locals.
479
480- Variants of several functions defined in pythonrun.h have been added
481 to support the nested_scopes future statement. The variants all end
482 in Flags and take an extra argument, a PyCompilerFlags *; examples:
483 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
484 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000485 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000486
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000487Distutils
488
489- the sdist command now writes a PKG-INFO file, as described in PEP 241,
490 into the release tree.
491
Tim Peters0e57abf2001-05-02 07:39:38 +0000492- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000493 (an uninstaller, more customization of the installer's display)
494
495- from Jack Jansen: added Mac-specific code to generate a dialog for
496 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000497 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000498 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000499
500- added 'platforms' and 'keywords' to the set of metadata that can be
501 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000502
503- applied patches from Jason Tishler to make the compiler class work with
504 Cygwin.
505
506
Tim Peters2fe289a2001-03-01 22:19:38 +0000507What's New in Python 2.1 beta 1?
508================================
Tim Petersd66595f2001-02-04 03:09:53 +0000509
510Core language, builtins, and interpreter
511
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000512- Following an outcry from the community about the amount of code
513 broken by the nested scopes feature introduced in 2.1a2, we decided
514 to make this feature optional, and to wait until Python 2.2 (or at
515 least 6 months) to make it standard. The option can be enabled on a
516 per-module basis by adding "from __future__ import nested_scopes" at
517 the beginning of a module (before any other statements, but after
518 comments and an optional docstring). See PEP 236 (Back to the
519 __future__) for a description of the __future__ statement. PEP 227
520 (Statically Nested Scopes) has been updated to reflect this change,
521 and to clarify the semantics in a number of endcases.
522
523- The nested scopes code, when enabled, has been hardened, and most
524 bugs and memory leaks in it have been fixed.
525
526- Compile-time warnings are now generated for a number of conditions
527 that will break or change in meaning when nested scopes are enabled:
528
529 - Using "from...import *" or "exec" without in-clause in a function
530 scope that also defines a lambda or nested function with one or
531 more free (non-local) variables. The presence of the import* or
532 bare exec makes it impossible for the compiler to determine the
533 exact set of local variables in the outer scope, which makes it
534 impossible to determine the bindings for free variables in the
535 inner scope. To avoid the warning about import *, change it into
536 an import of explicitly name object, or move the import* statement
537 to the global scope; to avoid the warning about bare exec, use
538 exec...in... (a good idea anyway -- there's a possibility that
539 bare exec will be deprecated in the future).
540
541 - Use of a global variable in a nested scope with the same name as a
542 local variable in a surrounding scope. This will change in
543 meaning with nested scopes: the name in the inner scope will
544 reference the variable in the outer scope rather than the global
545 of the same name. To avoid the warning, either rename the outer
546 variable, or use a global statement in the inner function.
547
Neil Schemenauera35c6882001-02-27 04:45:05 +0000548- An optional object allocator has been included. This allocator is
549 optimized for Python objects and should be faster and use less memory
550 than the standard system allocator. It is not enabled by default
551 because of possible thread safety problems. The allocator is only
552 protected by the Python interpreter lock and it is possible that some
553 extension modules require a thread safe allocator. The object
554 allocator can be enabled by providing the "--with-pymalloc" option to
555 configure.
556
Tim Petersd66595f2001-02-04 03:09:53 +0000557Standard library
558
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000559- pyexpat now detects the expat version if expat.h defines it. A
560 number of additional handlers are provided, which are only available
561 since expat 1.95. In addition, the methods SetParamEntityParsing and
562 GetInputContext of Parser objects are available with 1.95.x
563 only. Parser objects now provide the ordered_attributes and
564 specified_attributes attributes. A new module expat.model was added,
565 which offers a number of additional constants if 1.95.x is used.
566
567- xml.dom offers the new functions registerDOMImplementation and
568 getDOMImplementation.
569
570- xml.dom.minidom offers a toprettyxml method. A number of DOM
571 conformance issues have been resolved. In particular, Element now
572 has an hasAttributes method, and the handling of namespaces was
573 improved.
574
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000575- Ka-Ping Yee contributed two new modules: inspect.py, a module for
576 getting information about live Python code, and pydoc.py, a module
577 for interactively converting docstrings to HTML or text.
578 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000579 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000580 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
581 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000582
Tim Peters1eff7962001-03-01 02:31:33 +0000583- New library module difflib.py, primarily packaging the SequenceMatcher
584 class at the heart of the popular ndiff.py file-comparison tool.
585
586- doctest.py (a framework for verifying Python code examples in docstrings)
587 is now part of the std library.
588
Tim Petersd66595f2001-02-04 03:09:53 +0000589Windows changes
590
Guido van Rossume3955a82001-03-02 14:05:59 +0000591- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
592 small GUI that lets you browse the module docstrings using your
593 default web browser.
594
Tim Peters1eff7962001-03-01 02:31:33 +0000595- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
596 Platforms) is implemented. See
597
598 http://python.sourceforge.net/peps/pep-0235.html
599
600 for full details, especially the "Current Lower-Left Semantics" section.
601 The new Windows import rules are simpler than before:
602
603 A. If the PYTHONCASEOK environment variable exists, same as
604 before: silently accept the first case-insensitive match of any
605 kind; raise ImportError if none found.
606
607 B. Else search sys.path for the first case-sensitive match; raise
608 ImportError if none found.
609
610 The same rules have been implented on other platforms with case-
611 insensitive but case-preserving filesystems too (including Cygwin, and
612 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000613
Tim Peters25a9ce32001-02-19 07:06:36 +0000614- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
615 what it's supposed to do (and does do under NT and 2000) via direct
616 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000617 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000618 all Win9x systems before.
619
Tim Peters1eff7962001-03-01 02:31:33 +0000620- Build: Subproject _test (effectively) renamed to _testcapi.
621
Tim Peters2fe289a2001-03-01 22:19:38 +0000622New platforms
623
624- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
625 Thanks to Steven Majewski!
626
627- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
628 Tishler!
629
Guido van Rossum9089b272001-03-02 06:49:50 +0000630- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
631 Schwertberger! See RISCOS/README for more information -- it seems
632 that because of the bizarre filename conventions on RISCOS, no port
633 to that platform is easy. Note that the new variable os.endsep is
634 silently supported in order to make life easier on this platform,
635 but we don't advertise it because it's not worth for most folks to
636 care about RISCOS portability.
637
Tim Peters25a9ce32001-02-19 07:06:36 +0000638
Tim Petersd7b5e882001-01-25 03:36:26 +0000639What's New in Python 2.1 alpha 2?
640=================================
Tim Peters40ead762001-01-27 05:35:26 +0000641
Tim Petersd7b5e882001-01-25 03:36:26 +0000642Core language, builtins, and interpreter
643
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000644- Scopes nest. If a name is used in a function or class, but is not
645 local, the definition in the nearest enclosing function scope will
646 be used. One consequence of this change is that lambda statements
647 could reference variables in the namespaces where the lambda is
648 defined. In some unusual cases, this change will break code.
649
650 In all previous version of Python, names were resolved in exactly
651 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000652 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000653 function A is defined within a function B, the names bound in B are
654 not visible in A. The new rules make names bound in B visible in A,
655 unless A contains a name binding that hides the binding in B.
656
657 Section 4.1 of the reference manual describes the new scoping rules
658 in detail. The test script in Lib/test/test_scope.py demonstrates
659 some of the effects of the change.
660
661 The new rules will cause existing code to break if it defines nested
662 functions where an outer function has local variables with the same
663 name as globals or builtins used by the inner function. Example:
664
665 def munge(str):
666 def helper(x):
667 return str(x)
668 if type(str) != type(''):
669 str = helper(str)
670 return str.strip()
671
672 Under the old rules, the name str in helper() is bound to the
673 builtin function str(). Under the new rules, it will be bound to
674 the argument named str and an error will occur when helper() is
675 called.
676
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000677- The compiler will report a SyntaxError if "from ... import *" occurs
678 in a function or class scope. The language reference has documented
679 that this case is illegal, but the compiler never checked for it.
680 The recent introduction of nested scope makes the meaning of this
681 form of name binding ambiguous. In a future release, the compiler
682 may allow this form when there is no possibility of ambiguity.
683
Tim Peters40ead762001-01-27 05:35:26 +0000684- repr(string) is easier to read, now using hex escapes instead of octal,
685 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
686
687 >>> "\texample \r\n" + chr(0) + chr(255)
688 '\texample \r\n\x00\xff' # in 2.1
689 '\011example \015\012\000\377' # in 2.0
690
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000691- Functions are now compared and hashed by identity, not by value, since
692 the func_code attribute is writable.
693
Fred Drakefb9d7122001-02-01 20:00:40 +0000694- Weak references (PEP 205) have been added. This involves a few
695 changes in the core, an extension module (_weakref), and a Python
696 module (weakref). The weakref module is the public interface. It
697 includes support for "explicit" weak references, proxy objects, and
698 mappings with weakly held values.
699
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000700- A 'continue' statement can now appear in a try block within the body
701 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000702 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000703
Tim Petersd7b5e882001-01-25 03:36:26 +0000704Standard library
705
Barry Warsaw30dbd142001-01-31 22:14:01 +0000706- mailbox.py now has a new class, PortableUnixMailbox which is
707 identical to UnixMailbox but uses a more portable scheme for
708 determining From_ separators. Also, the constructors for all the
709 classes in this module have a new optional `factory' argument, which
710 is a callable used when new message classes must be instantiated by
711 the next() method.
712
Tim Petersd7b5e882001-01-25 03:36:26 +0000713- random.py is now self-contained, and offers all the functionality of
714 the now-deprecated whrandom.py. See the docs for details. random.py
715 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000716 and restoring the internal state of the generator; and jumpahead(n),
717 for quickly forcing the internal state to be the same as if n calls to
718 random() had been made. The latter is particularly useful for multi-
719 threaded programs, creating one instance of the random.Random() class for
720 each thread, then using .jumpahead() to force each instance to use a
721 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000722
Tim Peters0de88fc2001-02-01 04:59:18 +0000723- random.py's seed() function is new. For bit-for-bit compatibility with
724 prior releases, use the whseed function instead. The new seed function
725 addresses two problems: (1) The old function couldn't produce more than
726 about 2**24 distinct internal states; the new one about 2**45 (the best
727 that can be done in the Wichmann-Hill generator). (2) The old function
728 sometimes produced identical internal states when passed distinct
729 integers, and there was no simple way to predict when that would happen;
730 the new one guarantees to produce distinct internal states for all
731 arguments in [0, 27814431486576L).
732
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000733- The socket module now supports raw packets on Linux. The socket
734 family is AF_PACKET.
735
Tim Peters9ea17ac2001-02-02 05:57:15 +0000736- test_capi.py is a start at running tests of the Python C API. The tests
737 are implemented by the new Modules/_testmodule.c.
738
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000739- A new extension module, _symtable, provides provisional access to the
740 internal symbol table used by the Python compiler. A higher-level
741 interface will be added on top of _symtable in a future release.
742
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000743- Removed the obsolete soundex module.
744
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000745- xml.dom.minidom now uses the standard DOM exceptions. Node supports
746 the isSameNode method; NamedNodeMap the get method.
747
748- xml.sax.expatreader supports the lexical handler property; it
749 generates comment, startCDATA, and endCDATA events.
750
Tim Petersee826f82001-01-31 19:39:44 +0000751Windows changes
752
753- Build procedure: the zlib project is built in a different way that
754 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000755 the zlib binary used. See PCbuild\readme.txt for details. Your old
756 zlib-related directories can be deleted; you'll need to download fresh
757 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000758
Tim Peters9ea17ac2001-02-02 05:57:15 +0000759- Build: New subproject _test for the benefit of test_capi.py (see above).
760
Tim Petersb16c56f2001-02-02 21:24:51 +0000761- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
762 interface to some Python compiler internals).
763
764- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000765 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000766
Tim Petersa3a3a032000-11-30 05:22:44 +0000767What's New in Python 2.1 alpha 1?
768=================================
769
770Core language, builtins, and interpreter
771
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000772- There is a new Unicode companion to the PyObject_Str() API
773 called PyObject_Unicode(). It behaves in the same way as the
774 former, but assures that the returned value is an Unicode object
775 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000776
Guido van Rossumf98eda02001-01-17 15:54:45 +0000777- The comparison operators support "rich comparison overloading" (PEP
778 207). C extension types can provide a rich comparison function in
779 the new tp_richcompare slot in the type object. The cmp() function
780 and the C function PyObject_Compare() first try the new rich
781 comparison operators before trying the old 3-way comparison. There
782 is also a new C API PyObject_RichCompare() (which also falls back on
783 the old 3-way comparison, but does not constrain the outcome of the
784 rich comparison to a Boolean result).
785
786 The rich comparison function takes two objects (at least one of
787 which is guaranteed to have the type that provided the function) and
788 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
789 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
790 object, which may be NotImplemented (in which case the tp_compare
791 slot function is used as a fallback, if defined).
792
793 Classes can overload individual comparison operators by defining one
794 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000795 __ge__. There are no explicit "reflected argument" versions of
796 these; instead, __lt__ and __gt__ are each other's reflection,
797 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
798 reflection (similar at the C level). No other implications are
799 made; in particular, Python does not assume that == is the Boolean
800 inverse of !=, or that < is the Boolean inverse of >=. This makes
801 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000802
803 Classes or types that want to implement (in)equality tests but not
804 the ordering operators (i.e. unordered types) should implement ==
805 and !=, and raise an error for the ordering operators.
806
Guido van Rossuma88479f2001-01-18 14:28:08 +0000807 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000808 Boolean; e.g. a matrix type might want to return a matrix of bits
809 for A < B, giving elementwise comparisons. Such types should ensure
810 that any interpretation of their value in a Boolean context raises
811 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
812 at the C level) to always raise an exception.
813
Guido van Rossuma88479f2001-01-18 14:28:08 +0000814- Complex numbers use rich comparisons to define == and != but raise
815 an exception for <, <=, > and >=. Unfortunately, this also means
816 that cmp() of two complex numbers raises an exception when the two
817 numbers differ. Since it is not mathematically meaningful to compare
818 complex numbers except for equality, I hope that this doesn't break
819 too much code.
820
Tim Peters3389f192001-02-18 08:48:49 +0000821- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000822 not defined by the language, other than that it's arbitrary but
823 consistent (see the Reference Manual). An implementation detail changed
824 in 2.1a1 such that None now compares less than any other object. Code
825 relying on this new behavior (like code that relied on the previous
826 behavior) does so at its own risk.
827
Barry Warsaw573b5412001-01-15 20:43:18 +0000828- Functions and methods now support getting and setting arbitrarily
829 named attributes (PEP 232). Functions have a new __dict__
830 (a.k.a. func_dict) which hold the function attributes. Methods get
831 and set attributes on their underlying im_func. It is a TypeError
832 to set an attribute on a bound method.
833
Guido van Rossum051e3352001-01-15 19:11:10 +0000834- The xrange() object implementation has been improved so that
835 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
836 limitation that in this case len(xrange(sys.maxint)) can't be
837 calculated, but the common idiom "for i in xrange(sys.maxint)" will
838 work fine as long as the index i doesn't actually reach 2**31.
839 (Python uses regular ints for sequence and string indices; fixing
840 that is much more work.)
841
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000842- Two changes to from...import:
843
Guido van Rossumba381232001-02-03 15:06:40 +0000844 1) "from M import X" now works even if (after loading module M)
845 sys.modules['M'] is not a real module; it's basically a getattr()
846 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000847
848 2) "from M import *" now looks for M.__all__ to decide which names to
849 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
850 filters out names starting with '_' as before. Whether or not
851 __all__ exists, there's no restriction on the type of M.
852
Guido van Rossumf61f1662001-01-10 20:13:55 +0000853- File objects have a new method, xreadlines(). This is the fastest
854 way to iterate over all lines in a file:
855
856 for line in file.xreadlines():
857 ...do something to line...
858
859 See the xreadlines module (mentioned below) for how to do this for
860 other file-like objects.
861
862- Even if you don't use file.xreadlines(), you may expect a speedup on
863 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000864 quite a bit in platform-specific ways: on systems (like Linux) that
865 support flockfile(), getc_unlocked(), and funlockfile(), those are
866 used by default. On systems (like Windows) without getc_unlocked(),
867 a complicated (but still thread-safe) method using fgets() is used by
868 default.
869
Tim Petersd52269b2001-01-25 06:23:18 +0000870 You can force use of the fgets() method by #define'ing
871 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000872 getc_unlocked()).
873
Tim Petersd52269b2001-01-25 06:23:18 +0000874 You can force fgets() not to be used by #define'ing
875 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000876 test_bufio.py fails -- and let us know if it does!).
877
878- In addition, the fileinput module, while still slower than the other
879 methods on most platforms, has been sped up too, by using
880 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000881
882- Support for run-time warnings has been added, including a new
883 command line option (-W) to specify the disposition of warnings.
884 See the description of the warnings module below.
885
886- Extensive changes have been made to the coercion code. This mostly
887 affects extension modules (which can now implement mixed-type
888 numerical operators without having to use coercion), but
889 occasionally, in boundary cases the coercion semantics have changed
890 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000891 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000892 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000893 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000894
Guido van Rossumf98eda02001-01-17 15:54:45 +0000895- In connection with the coercion changes, a new built-in singleton
896 object, NotImplemented is defined. This can be returned for
897 operations that wish to indicate they are not implemented for a
898 particular combination of arguments. From C, this is
899 Py_NotImplemented.
900
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000901- The interpreter accepts now bytecode files on the command line even
902 if they do not have a .pyc or .pyo extension. On Linux, after executing
903
Martin v. Löwise214baa2001-02-04 22:37:56 +0000904import imp,sys,string
905magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
906reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
907open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000908
909 any byte code file can be used as an executable (i.e. as an argument
910 to execve(2)).
911
Tim Peters9940b802000-12-01 07:59:35 +0000912- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000913 character. In 1.6 and earlier, they never produced a sign,
914 and raised an error if the value of the long was too large
915 to fit in a Python int. In 2.0, they produced a sign if and
916 only if too large to fit in an int. This was inconsistent
917 across platforms (because the size of an int varies across
918 platforms), and inconsistent with hex() and oct(). Example:
919
920 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000921 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000922 'ffffffbe' # in 2.0 and before, on 32-bit machines
923 >>> hex(-0x42L)
924 '-0x42L' # in all versions of Python
925
Tim Peters9940b802000-12-01 07:59:35 +0000926 The behavior of %d formats for negative Python longs remains
927 the same as in 2.0 (although in 1.6 and before, they raised
928 an error if the long didn't fit in a Python int).
929
930 %u formats don't make sense for Python longs, but are allowed
931 and treated the same as %d in 2.1. In 2.0, a negative long
932 formatted via %u produced a sign if and only if too large to
933 fit in an int. In 1.6 and earlier, a negative long formatted
934 via %u raised an error if it was too big to fit in an int.
935
Guido van Rossum3661d392000-12-12 22:10:31 +0000936- Dictionary objects have an odd new method, popitem(). This removes
937 an arbitrary item from the dictionary and returns it (in the form of
938 a (key, value) pair). This can be useful for algorithms that use a
939 dictionary as a bag of "to do" items and repeatedly need to pick one
940 item. Such algorithms normally end up running in quadratic time;
941 using popitem() they can usually be made to run in linear time.
942
Tim Peters36cdad12000-12-29 02:06:45 +0000943Standard library
944
Thomas Woutersfe385252001-01-19 23:16:56 +0000945- In the time module, the time argument to the functions strftime,
946 localtime, gmtime, asctime and ctime is now optional, defaulting to
947 the current time (in the local timezone).
948
Guido van Rossumda91f222001-01-15 16:36:08 +0000949- The ftplib module now defaults to passive mode, which is deemed a
950 more useful default given that clients are often inside firewalls
951 these days. Note that this could break if ftplib is used to connect
952 to a *server* that is inside a firewall, from outside; this is
953 expected to be a very rare situation. To fix that, you can call
954 ftp.set_pasv(0).
955
Martin v. Löwis10a27872001-01-13 09:54:41 +0000956- The module site now treats .pth files not only for path configuration,
957 but also supports extensions to the initialization code: Lines starting
958 with import are executed.
959
Guido van Rossumf61f1662001-01-10 20:13:55 +0000960- There's a new module, warnings, which implements a mechanism for
961 issuing and filtering warnings. There are some new built-in
962 exceptions that serve as warning categories, and a new command line
963 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
964 turns warnings into errors). warnings.warn(message[, category])
965 issues a warning message; this can also be called from C as
966 PyErr_Warn(category, message).
967
968- A new module xreadlines was added. This exports a single factory
969 function, xreadlines(). The intention is that this code is the
970 absolutely fastest way to iterate over all lines in an open
971 file(-like) object:
972
973 import xreadlines
974 for line in xreadlines.xreadlines(file):
975 ...do something to line...
976
977 This is equivalent to the previous the speed record holder using
978 file.readlines(sizehint). Note that if file is a real file object
979 (as opposed to a file-like object), this is equivalent:
980
981 for line in file.xreadlines():
982 ...do something to line...
983
Tim Peters36cdad12000-12-29 02:06:45 +0000984- The bisect module has new functions bisect_left, insort_left,
985 bisect_right and insort_right. The old names bisect and insort
986 are now aliases for bisect_right and insort_right. XXX_right
987 and XXX_left methods differ in what happens when the new element
988 compares equal to one or more elements already in the list: the
989 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000990 right. Code that doesn't care where equal elements end up should
991 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000992
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000993- The new curses.panel module wraps the panel library that forms part
994 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
995
Guido van Rossumf61f1662001-01-10 20:13:55 +0000996- The SocketServer module now sets the allow_reuse_address flag by
997 default in the TCPServer class.
998
999- A new function, sys._getframe(), returns the stack frame pointer of
1000 the caller. This is intended only as a building block for
1001 higher-level mechanisms such as string interpolation.
1002
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001003- The pyexpat module supports a number of new handlers, which are
1004 available only in expat 1.2. If invocation of a callback fails, it
1005 will report an additional frame in the traceback. Parser objects
1006 participate now in garbage collection. If expat reports an unknown
1007 encoding, pyexpat will try to use a Python codec; that works only
1008 for single-byte charsets. The parser type objects is exposed as
1009 XMLParserObject.
1010
1011- xml.dom now offers standard definitions for symbolic node type and
1012 exception code constants, and a hierarchy of DOM exceptions. minidom
1013 was adjusted to use them.
1014
1015- The conformance of xml.dom.minidom to the DOM specification was
1016 improved. It detects a number of additional error cases; the
1017 previous/next relationship works even when the tree is modified;
1018 Node supports the normalize() method; NamedNodeMap, DocumentType and
1019 DOMImplementation classes were added; Element supports the
1020 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1021 method.
1022
Guido van Rossumf61f1662001-01-10 20:13:55 +00001023Build issues
1024
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001025- For Unix (and Unix-compatible) builds, configuration and building of
1026 extension modules is now greatly automated. Rather than having to
1027 edit the Modules/Setup file to indicate which modules should be
1028 built and where their include files and libraries are, a
1029 distutils-based setup.py script now takes care of building most
1030 extension modules. All extension modules built this way are built
1031 as shared libraries. Only a few modules that must be linked
1032 statically are still listed in the Setup file; you won't need to
1033 edit their configuration.
1034
1035- Python should now build out of the box on Cygwin. If it doesn't,
1036 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001037
1038- Python now always uses its own (renamed) implementation of getopt()
1039 -- there's too much variation among C library getopt()
1040 implementations.
1041
1042- C++ compilers are better supported; the CXX macro is always set to a
1043 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001044
Tim Petersd92dfe02000-12-12 01:18:41 +00001045Windows changes
1046
1047- select module: By default under Windows, a select() call
1048 can specify no more than 64 sockets. Python now boosts
1049 this Microsoft default to 512. If you need even more than
1050 that, see the MS docs (you'll need to #define FD_SETSIZE
1051 and recompile Python from source).
1052
Guido van Rossumf61f1662001-01-10 20:13:55 +00001053- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1054 subdirectory is no more!
1055
Tim Petersa3a3a032000-11-30 05:22:44 +00001056
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001057What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001058=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001059
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001060Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001061changes are in the file HISTORY. If you are making the jump directly
1062from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1063HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001064
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001065Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1066the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1067http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001068
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001069--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001070
1071======================================================================
1072
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001073What's new in 2.0 (since release candidate 1)?
1074==============================================
1075
1076Standard library
1077
1078- The copy_reg module was modified to clarify its intended use: to
1079 register pickle support for extension types, not for classes.
1080 pickle() will raise a TypeError if it is passed a class.
1081
1082- Fixed a bug in gettext's "normalize and expand" code that prevented
1083 it from finding an existing .mo file.
1084
1085- Restored support for HTTP/0.9 servers in httplib.
1086
Tim Peters989b7b92000-10-16 20:24:53 +00001087- The math module was changed to stop raising OverflowError in case of
1088 underflow, and return 0 instead in underflow cases. Whether Python
1089 used to raise OverflowError in case of underflow was platform-
1090 dependent (it did when the platform math library set errno to ERANGE
1091 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001092
1093- Fixed a bug in StringIO that occurred when the file position was not
1094 at the end of the file and write() was called with enough data to
1095 extend past the end of the file.
1096
1097- Fixed a bug that caused Tkinter error messages to get lost on
1098 Windows. The bug was fixed by replacing direct use of
1099 interp->result with Tcl_GetStringResult(interp).
1100
1101- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1102 redirect response.
1103
1104- Several changes were made to distutils: Some debugging code was
1105 removed from util. Fixed the installer used when an external zip
1106 program (like WinZip) is not found; the source code for this
1107 installer is in Misc/distutils. check_lib() was modified to behave
1108 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1109 test for whether installed modules are on sys.path was changed to
1110 use both normcase() and normpath().
1111
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001112- Several minor bugs were fixed in the xml package (the minidom,
1113 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001114
1115- The regression test driver (regrtest.py) behavior when invoked with
1116 -l changed: It now reports a count of objects that are recognized as
1117 garbage but not freed by the garbage collector.
1118
Tim Peters989b7b92000-10-16 20:24:53 +00001119- The regression test for the math module was changed to test
1120 exceptional behavior when the test is run in verbose mode. Python
1121 cannot yet guarantee consistent exception behavior across platforms,
1122 so the exception part of test_math is run only in verbose mode, and
1123 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001124
1125Internals
1126
1127- PyOS_CheckStack() has been disabled on Win64, where it caused
1128 test_sre to fail.
1129
1130Build issues
1131
1132- Changed compiler flags, so that gcc is always invoked with -Wall and
1133 -Wstrict-prototypes. Users compiling Python with GCC should see
1134 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001135 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001136 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001137
Tim Petersa3a3a032000-11-30 05:22:44 +00001138- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001139
1140Tools and other miscellany
1141
1142- The compiler in Tools/compiler was updated to support the new
1143 language features introduced in 2.0: extended print statement, list
1144 comprehensions, and augmented assignments. The new compiler should
1145 also be backwards compatible with Python 1.5.2; the compiler will
1146 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001147 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001148
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001149What's new in 2.0 release candidate 1 (since beta 2)?
1150=====================================================
1151
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001152What is release candidate 1?
1153
1154We believe that release candidate 1 will fix all known bugs that we
1155intend to fix for the 2.0 final release. This release should be a bit
1156more stable than the previous betas. We would like to see even more
1157widespread testing before the final release, so we are producing this
1158release candidate. The final release will be exactly the same unless
1159any show-stopping (or brown bag) bugs are found by testers of the
1160release candidate.
1161
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001162All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001163to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001164
1165Core language, builtins, and interpreter
1166
1167- A bug that caused crashes when __coerce__ was used with augmented
1168 assignment, e.g. +=, was fixed.
1169
1170- Raise ZeroDivisionError when raising zero to a negative number,
1171 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1172 power operator and the result of math.pow(0.0, -2.0) will vary by
1173 platform. On Linux, it raises a ValueError.
1174
1175- A bug in Unicode string interpolation was fixed that occasionally
1176 caused errors with formats including "%%". For example, the
1177 following expression "%% %s" % u"abc" no longer raises a TypeError.
1178
1179- Compilation of deeply nested expressions raises MemoryError instead
1180 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1181
1182- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1183 rendering them useless. They are now written in binary mode again.
1184
1185Standard library
1186
1187- Keyword arguments are now accepted for most pattern and match object
1188 methods in SRE, the standard regular expression engine.
1189
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001190- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001191 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001192
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001193- Several bugs in the Unicode handling and error handling in _tkinter
1194 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001195
1196- Fix memory management errors in Merge() and Tkapp_Call() routines.
1197
1198- Several changes were made to cStringIO to make it compatible with
1199 the file-like object interface and with StringIO. If operations are
1200 performed on a closed object, an exception is raised. The truncate
1201 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001202 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001203
1204- There were many changes made to the linuxaudiodev module and its
1205 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001206 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001207
1208 Note that this module is named poorly, because it should work
1209 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001210 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001211
1212 The module now raises exceptions when errors occur instead of
1213 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1214 audio) and defines a getptr() method that calls the
1215 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1216
1217- The library_version attribute, introduced in an earlier beta, was
1218 removed because it can not be supported with early versions of the C
1219 readline library, which provides no way to determine the version at
1220 compile-time.
1221
1222- The binascii module is now enabled on Win64.
1223
Tim Peters46446d62000-10-09 21:19:31 +00001224- tokenize.py no longer suffers "recursion depth" errors when parsing
1225 programs with very long string literals.
1226
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001227Internals
1228
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001229- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001230 which is called when the interpreter starts up to determine where
1231 the standard library is installed. These vulnerabilities affect all
1232 previous versions of Python and can be exploited by setting very
1233 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1234 setuid Python script, although use of the wrapper in
1235 Misc/setuid-prog.c will eliminate the vulnerability.
1236
1237- Fixed garbage collection bugs in instance creation that were
1238 triggered when errors occurred during initialization. The solution,
1239 applied in cPickle and in PyInstance_New(), is to call
1240 PyObject_GC_Init() after the initialization of the object's
1241 container attributes is complete.
1242
1243- pyexpat adds definitions of PyModule_AddStringConstant and
1244 PyModule_AddObject if the Python version is less than 2.0, which
1245 provides compatibility with PyXML on Python 1.5.2.
1246
1247- If the platform has a bogus definition for LONG_BIT (the number of
1248 bits in a long), an error will be reported at compile time.
1249
1250- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1251 collection crashes and possibly other, unreported crashes.
1252
1253- Fixed a memory leak in _PyUnicode_Fini().
1254
1255Build issues
1256
1257- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001258 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001259 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001260
1261- The mmap.PAGESIZE constant is now initialized using sysconf when
1262 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1263
1264- The md5 file should now compile on all platforms.
1265
1266- The select module now compiles on platforms that do not define
1267 POLLRDNORM and related constants.
1268
1269- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001270 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001271
Jeremy Hylton10921202000-10-09 18:34:12 +00001272- BeOS: A number of changes were made to the build and installation
1273 process. ar-fake now operates on a directory of object files.
1274 dl_export.h is gone, and its macros now appear on the mwcc command
1275 line during build on PPC BeOS.
1276
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001277- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001278 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001279
1280- Cygwin: Support for shared libraries, Tkinter, and sockets.
1281
1282- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1283
1284Tools and other miscellany
1285
1286- Removed debugging prints from main used with freeze.
1287
Tim Peters46446d62000-10-09 21:19:31 +00001288- IDLE auto-indent no longer crashes when it encounters Unicode
1289 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001290
1291What's new in 2.0 beta 2 (since beta 1)?
1292========================================
1293
1294Core language, builtins, and interpreter
1295
Tim Peters482c0212000-09-26 06:33:09 +00001296- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001297 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001298
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001299- Add -h and -V command line options to print the usage message and
1300 Python version number and exit immediately.
1301
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001302- eval() and exec accept Unicode objects as code parameters.
1303
1304- getattr() and setattr() now also accept Unicode objects for the
1305 attribute name, which are converted to strings using the default
1306 encoding before lookup.
1307
1308- Multiplication on string and Unicode now does proper bounds
1309 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1310 string is too long."
1311
1312- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001313 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001314
Jeremy Hylton1b618592000-09-26 05:32:36 +00001315
1316Standard library and extensions
1317
Guido van Rossum5b08f132001-04-16 02:05:23 +00001318- socket module: the OpenSSL code now adds support for RAND_status()
1319 and EGD (Entropy Gathering Device).
1320
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001321- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001322 argument checking; it still takes no arguments.
1323
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001324- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001325
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001326- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001327
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001328- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001329
1330- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001331 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001332
1333- copy: Copy Unicode objects atomically.
1334
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001335- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001336
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001337- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001338
Fred Drake67233bc2000-09-26 16:40:27 +00001339- dbm: Add get() and setdefault() methods to dbm object. Add constant
1340 `library' to module that names the library used. Added doc strings
1341 and method names to error messages. Uses configure to determine
1342 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1343 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001344
1345- distutils: Update to version 0.9.3.
1346
1347- dl: Add several dl.RTLD_ constants.
1348
1349- fpectl: Now supported on FreeBSD.
1350
1351- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1352 found by the collector will be saved in gc.garbage. This is useful
1353 for debugging a program that creates reference cycles.
1354
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001355- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001356 of HTTP class. Do not close socket on zero-length response. Do not
1357 crash when server sends invalid content-length header.
1358
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001359- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001360
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001361- marshal: When reading a short, sign-extend on platforms where shorts
1362 are bigger than 16 bits. When reading a long, repair the unportable
1363 sign extension that was being done for 64-bit machines. (It assumed
1364 that signed right shift sign-extends.)
1365
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001366- operator: Add contains(), invert(), __invert__() as aliases for
1367 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001368
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001369- os: Add support for popen2() and popen3() on all platforms where
1370 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001371
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001372- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001373 clicking on a file in Explorer (or passing the file name to the
1374 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001375
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001376- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001377 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001378
1379- pickle: Now raises ValueError when an invalid pickle that contains
1380 a non-string repr where a string repr was expected. This behavior
1381 matches cPickle.
1382
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001383- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001384
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001385- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001386
1387- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001388 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001389 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001390
1391- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001392 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001393
1394- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001395 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001396 few cycles during startup since the first call to
1397 setdefaultencoding() will initialize the codec registry and the
1398 encodings package.
1399
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001400- socket: Support for size hint in readlines() method of object returned
1401 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001402
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001403- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001404 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001405 is followed by whitespace.
1406
Tim Petersa3a3a032000-11-30 05:22:44 +00001407- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001408
1409- struct: Check ranges for bytes and shorts.
1410
1411- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001412 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001413
1414- Tkinter: Image objects are now guaranteed to have unique ids. Set
1415 event.delta to zero if Tk version doesn't support mousewheel.
1416 Removed some debugging prints.
1417
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001418- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001419
Fred Drake67233bc2000-09-26 16:40:27 +00001420- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001421 which works around a bug in Norton AntiVirus 2000 that leads directly
1422 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001423
1424- xml: New version detection code allows PyXML to override standard
1425 XML package if PyXML version is greater than 0.6.1.
1426
Fred Drake64bb3802000-09-26 16:21:35 +00001427- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1428 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1429 tree only for nodes which are sufficiently interesting to a specific
1430 application. Does not provide the HTML-specific extensions. Still
1431 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001432
Fred Drake64bb3802000-09-26 16:21:35 +00001433- xml.sax: SAX 2 support for Python, including all the handler
1434 interfaces needed to process XML 1.0 compliant XML. Some
1435 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001436
Fred Drake64bb3802000-09-26 16:21:35 +00001437- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1438 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001439
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001440
Jeremy Hylton1b618592000-09-26 05:32:36 +00001441C API
1442
1443- Add three new convenience functions for module initialization --
1444 PyModule_AddObject(), PyModule_AddIntConstant(), and
1445 PyModule_AddStringConstant().
1446
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001447- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001448 removed and add #error to Python.h if NULL isn't defined after
1449 #include of stdio.h.
1450
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001451- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001452 backwards compatibility (at the source level) with old extensions.
1453
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001454- A wrapper API was added for signal() and sigaction(). Instead of
1455 either function, always use PyOS_getsig() to get a signal handler
1456 and PyOS_setsig() to set one. A new convenience typedef
1457 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001458
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001459- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001460 internal data buffer and size of a string object -- or the default
1461 encoded version of a Unicode object.
1462
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001463- PyString_Size() and PyString_AsString() accept Unicode objects.
1464
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001465- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001466 exists). INT_MAX and LONG_MAX will always be defined, even if
1467 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001468
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001469- PyFloat_FromString takes a second argument, pend, that was
1470 effectively useless. It is now officially useless but preserved for
1471 backwards compatibility. If the pend argument is not NULL, *pend is
1472 set to NULL.
1473
1474- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1475 for the attribute name. See note on getattr() above.
1476
1477- A few bug fixes to argument processing for Unicode.
1478 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1479 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1480 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001481 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001482
1483- Py_BuildValue accepts B format (for bgen-generated code).
1484
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001485
Jeremy Hylton1b618592000-09-26 05:32:36 +00001486Internals
1487
1488- On Unix, fix code for finding Python installation directory so that
1489 it works when argv[0] is a relative path.
1490
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001491- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001492 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001493 rather than by generating a copy of the object.
1494
Tim Peters482c0212000-09-26 06:33:09 +00001495- Several of the internal Unicode tables are much smaller now, and
1496 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001497
Jeremy Hylton97693b02000-09-26 17:42:51 +00001498- In the garbage collector: Fixed bug in collection of tuples. Fixed
1499 bug that caused some instances to be removed from the container set
1500 while they were still live. Fixed parsing in gc.set_debug() for
1501 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001502
1503- Fixed refcount problem in instance deallocation that only occurred
1504 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1505
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001506- On Windows, getpythonregpath is now protected against null data in
1507 registry key.
1508
1509- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001510 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001511
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001512
Jeremy Hylton1b618592000-09-26 05:32:36 +00001513Build and platform-specific issues
1514
1515- Better support of GNU Pth via --with-pth configure option.
1516
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001517- Python/C API now properly exposed to dynamically-loaded extension
1518 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001519
1520- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1521 Don't define MS_SYNC to be zero when it is undefined. Added missing
1522 prototypes in posixmodule.c.
1523
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001524- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001525 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001526
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001527- Fix largefile support on older NetBSD systems and OpenBSD by adding
1528 define for TELL64.
1529
1530
1531Tools and other miscellany
1532
1533- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1534
1535- freeze: The modulefinder now works with 2.0 opcodes.
1536
Tim Petersa3a3a032000-11-30 05:22:44 +00001537- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001538 Move hackery of sys.argv until after the Tk instance has been
1539 created, which allows the application-specific Tkinter
1540 initialization to be executed if present; also pass an explicit
1541 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001542
Jeremy Hylton1b618592000-09-26 05:32:36 +00001543
1544What's new in 2.0 beta 1?
1545=========================
1546
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001547Source Incompatibilities
1548------------------------
1549
1550None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1551such as single-argument append(), connect() and bind(), and changes to
1552str(long) and repr(float).
1553
1554
1555Binary Incompatibilities
1556------------------------
1557
1558- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1559with Python 2.0; these extensions will have to be rebuilt for Python
15602.0.
1561
1562- On Windows, attempting to import a third party extension built for
1563Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1564can do about this. Check your PYTHONPATH environment variable!
1565
1566- Python bytecode files (*.pyc and *.pyo) are not compatible between
1567releases.
1568
1569
1570Overview of Changes Since 1.6
1571-----------------------------
1572
1573There are many new modules (including brand new XML support through
1574the xml package, and i18n support through the gettext module); a list
1575of all new modules is included below. Lots of bugs have been fixed.
1576
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001577The process for making major new changes to the language has changed
1578since Python 1.6. Enhancements must now be documented by a Python
1579Enhancement Proposal (PEP) before they can be accepted.
1580
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001581There are several important syntax enhancements, described in more
1582detail below:
1583
1584 - Augmented assignment, e.g. x += 1
1585
1586 - List comprehensions, e.g. [x**2 for x in range(10)]
1587
1588 - Extended import statement, e.g. import Module as Name
1589
1590 - Extended print statement, e.g. print >> file, "Hello"
1591
1592Other important changes:
1593
1594 - Optional collection of cyclical garbage
1595
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001596Python Enhancement Proposal (PEP)
1597---------------------------------
1598
1599PEP stands for Python Enhancement Proposal. A PEP is a design
1600document providing information to the Python community, or describing
1601a new feature for Python. The PEP should provide a concise technical
1602specification of the feature and a rationale for the feature.
1603
1604We intend PEPs to be the primary mechanisms for proposing new
1605features, for collecting community input on an issue, and for
1606documenting the design decisions that have gone into Python. The PEP
1607author is responsible for building consensus within the community and
1608documenting dissenting opinions.
1609
1610The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001611
1612Augmented Assignment
1613--------------------
1614
1615This must have been the most-requested feature of the past years!
1616Eleven new assignment operators were added:
1617
Guido van Rossume905e952000-09-05 12:42:46 +00001618 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001619
1620For example,
1621
1622 A += B
1623
1624is similar to
1625
1626 A = A + B
1627
1628except that A is evaluated only once (relevant when A is something
1629like dict[index].attr).
1630
1631However, if A is a mutable object, A may be modified in place. Thus,
1632if A is a number or a string, A += B has the same effect as A = A+B
1633(except A is only evaluated once); but if a is a list, A += B has the
1634same effect as A.extend(B)!
1635
1636Classes and built-in object types can override the new operators in
1637order to implement the in-place behavior; the not-in-place behavior is
1638used automatically as a fallback when an object doesn't implement the
1639in-place behavior. For classes, the method name is derived from the
1640method name for the corresponding not-in-place operator by inserting
1641an 'i' in front of the name, e.g. __iadd__ implements in-place
1642__add__.
1643
1644Augmented assignment was implemented by Thomas Wouters.
1645
1646
1647List Comprehensions
1648-------------------
1649
1650This is a flexible new notation for lists whose elements are computed
1651from another list (or lists). The simplest form is:
1652
1653 [<expression> for <variable> in <sequence>]
1654
Guido van Rossum56db0952000-09-06 23:34:25 +00001655For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001656This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001657
1658You can also add a condition:
1659
1660 [<expression> for <variable> in <sequence> if <condition>]
1661
1662For example, [w for w in words if w == w.lower()] would yield the list
1663of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001664than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001665
1666You can also have nested for loops and more than one 'if' clause. For
1667example, here's a function that flattens a sequence of sequences::
1668
1669 def flatten(seq):
1670 return [x for subseq in seq for x in subseq]
1671
1672 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1673
1674This prints
1675
1676 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1677
1678List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001679Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001680
1681
1682Extended Import Statement
1683-------------------------
1684
1685Many people have asked for a way to import a module under a different
1686name. This can be accomplished like this:
1687
1688 import foo
1689 bar = foo
1690 del foo
1691
1692but this common idiom gets old quickly. A simple extension of the
1693import statement now allows this to be written as follows:
1694
1695 import foo as bar
1696
1697There's also a variant for 'from ... import':
1698
1699 from foo import bar as spam
1700
1701This also works with packages; e.g. you can write this:
1702
1703 import test.regrtest as regrtest
1704
1705Note that 'as' is not a new keyword -- it is recognized only in this
1706context (this is only possible because the syntax for the import
1707statement doesn't involve expressions).
1708
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001709Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001710
1711
1712Extended Print Statement
1713------------------------
1714
1715Easily the most controversial new feature, this extension to the print
1716statement adds an option to make the output go to a different file
1717than the default sys.stdout.
1718
1719For example, to write an error message to sys.stderr, you can now
1720write:
1721
1722 print >> sys.stderr, "Error: bad dog!"
1723
1724As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001725evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001726
1727 print >> None, "Hello world"
1728
1729is equivalent to
1730
1731 print "Hello world"
1732
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001733Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001734
1735
1736Optional Collection of Cyclical Garbage
1737---------------------------------------
1738
1739Python is now equipped with a garbage collector that can hunt down
1740cyclical references between Python objects. It's no replacement for
1741reference counting; in fact, it depends on the reference counts being
1742correct, and decides that a set of objects belong to a cycle if all
1743their reference counts can be accounted for from their references to
1744each other. This devious scheme was first proposed by Eric Tiedemann,
1745and brought to implementation by Neil Schemenauer.
1746
1747There's a module "gc" that lets you control some parameters of the
1748garbage collection. There's also an option to the configure script
1749that lets you enable or disable the garbage collection. In 2.0b1,
1750it's on by default, so that we (hopefully) can collect decent user
1751experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001752performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001753off by default in the final 2.0 release.
1754
1755
1756Smaller Changes
1757---------------
1758
1759A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1760map(None, seq1, seq2, ...) when the sequences have the same length;
1761i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1762the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001763zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001764
1765sys.version_info is a tuple (major, minor, micro, level, serial).
1766
1767Dictionaries have an odd new method, setdefault(key, default).
1768dict.setdefault(key, default) returns dict[key] if it exists; if not,
1769it sets dict[key] to default and returns that value. Thus:
1770
1771 dict.setdefault(key, []).append(item)
1772
1773does the same work as this common idiom:
1774
1775 if not dict.has_key(key):
1776 dict[key] = []
1777 dict[key].append(item)
1778
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001779There are two new variants of SyntaxError that are raised for
1780indentation-related errors: IndentationError and TabError.
1781
1782Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1783escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001784
1785The limits on the size of expressions and file in Python source code
1786have been raised from 2**16 to 2**32. Previous versions of Python
1787were limited because the maximum argument size the Python VM accepted
1788was 2**16. This limited the size of object constructor expressions,
1789e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1790limit was raised thanks to a patch by Charles Waldman that effectively
1791fixes the problem. It is now much more likely that you will be
1792limited by available memory than by an arbitrary limit in Python.
1793
1794The interpreter's maximum recursion depth can be modified by Python
1795programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1796limit is the maximum number of recursive calls that can be made by
1797Python code. The limit exists to prevent infinite recursion from
1798overflowing the C stack and causing a core dump. The default value is
17991000. The maximum safe value for a particular platform can be found
1800by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001801
1802New Modules and Packages
1803------------------------
1804
1805atexit - for registering functions to be called when Python exits.
1806
1807imputil - Greg Stein's alternative API for writing custom import
1808hooks.
1809
1810pyexpat - an interface to the Expat XML parser, contributed by Paul
1811Prescod.
1812
1813xml - a new package with XML support code organized (so far) in three
1814subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1815would fill a volume. There's a special feature whereby a
1816user-installed package named _xmlplus overrides the standard
1817xmlpackage; this is intended to give the XML SIG a hook to distribute
1818backwards-compatible updates to the standard xml package.
1819
1820webbrowser - a platform-independent API to launch a web browser.
1821
1822
Guido van Rossume905e952000-09-05 12:42:46 +00001823Changed Modules
1824---------------
1825
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001826array -- new methods for array objects: count, extend, index, pop, and
1827remove
1828
1829binascii -- new functions b2a_hex and a2b_hex that convert between
1830binary data and its hex representation
1831
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001832calendar -- Many new functions that support features including control
1833over which day of the week is the first day, returning strings instead
1834of printing them. Also new symbolic constants for days of week,
1835e.g. MONDAY, ..., SUNDAY.
1836
1837cgi -- FieldStorage objects have a getvalue method that works like a
1838dictionary's get method and returns the value attribute of the object.
1839
1840ConfigParser -- The parser object has new methods has_option,
1841remove_section, remove_option, set, and write. They allow the module
1842to be used for writing config files as well as reading them.
1843
1844ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001845optionally support the RFC 959 REST command.
1846
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001847gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001848
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001849httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1850the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001851
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001852locale -- implement getdefaultlocale for Win32 and Macintosh
1853
1854marshal -- no longer dumps core when marshaling deeply nested or
1855recursive data structures
1856
1857os -- new functions isatty, seteuid, setegid, setreuid, setregid
1858
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001859os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1860support under Unix.
1861
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001862os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001863
1864os.path -- fix semantics of os.path.commonprefix
1865
1866smtplib -- support for sending very long messages
1867
1868socket -- new function getfqdn()
1869
1870readline -- new functions to read, write and truncate history files.
1871The readline section of the library reference manual contains an
1872example.
1873
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001874select -- add interface to poll system call
1875
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001876shutil -- new copyfileobj function
1877
1878SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1879HTTP server.
1880
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001881Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001882
1883urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001884e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001885
1886whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001887
1888
1889Obsolete Modules
1890----------------
1891
1892None. However note that 1.6 made a whole slew of modules obsolete:
1893stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1894poly, zmod, strop, util, whatsound.
1895
1896
1897Changed, New, Obsolete Tools
1898----------------------------
1899
Tim Peters8b092332000-09-05 20:15:25 +00001900None.
Guido van Rossume905e952000-09-05 12:42:46 +00001901
1902
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001903C-level Changes
1904---------------
1905
1906Several cleanup jobs were carried out throughout the source code.
1907
1908All C code was converted to ANSI C; we got rid of all uses of the
1909Py_PROTO() macro, which makes the header files a lot more readable.
1910
1911Most of the portability hacks were moved to a new header file,
1912pyport.h; several other new header files were added and some old
1913header files were removed, in an attempt to create a more rational set
1914of header files. (Few of these ever need to be included explicitly;
1915they are all included by Python.h.)
1916
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001917Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001918and Win64, especially for the new Intel Itanium processor. Mick also
1919added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001920
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001921The C APIs to return an object's size have been update to consistently
1922use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1923previous versions, the abstract interfaces used PyXXX_Length and the
1924concrete interfaces used PyXXX_Size. The old names,
1925e.g. PyObject_Length, are still available for backwards compatibility
1926at the API level, but are deprecated.
1927
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001928The PyOS_CheckStack function has been implemented on Windows by
1929Fredrik Lundh. It prevents Python from failing with a stack overflow
1930on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001931
1932The GC changes resulted in creation of two new slots on object,
1933tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001934the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001935
1936The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001937C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001938
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001939PyErr_Format has been updated to automatically calculate the size of
1940the buffer needed to hold the formatted result string. This change
1941prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001942
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001943New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001944
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001945PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1946that are the same as their non-Ex counterparts except they take an
1947extra flag argument that tells them to close the file when done.
1948
1949XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001950
Tim Peters8b092332000-09-05 20:15:25 +00001951
1952Windows Changes
1953---------------
1954
1955New popen2/popen3/peopen4 in os module (see Changed Modules above).
1956
1957os.popen is much more usable on Windows 95 and 98. See Microsoft
1958Knowledge Base article Q150956. The Win9x workaround described there
1959is implemented by the new w9xpopen.exe helper in the root of your
1960Python installation. Note that Python uses this internally; it is not
1961a standalone program.
1962
1963Administrator privileges are no longer required to install Python
1964on Windows NT or Windows 2000. If you have administrator privileges,
1965Python's registry info will be written under HKEY_LOCAL_MACHINE.
1966Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001967under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001968uses of Python, but will prevent some advanced uses from working
1969(for example, running a Python script as an NT service, or possibly
1970from CGI).
1971
1972[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1973installer; instead, it installs the needed Tcl/Tk files directly in the
1974Python directory. If you already have a Tcl/Tk installation, this
1975wastes some disk space (about 4 Megs) but avoids problems with
1976conflicting Tcl/Tk installations, and makes it much easier for Python
1977to ensure that Tcl/Tk can find all its files.
1978
1979[This was new in 1.6] The Windows installer now installs by default in
1980\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1981
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001982
1983Updates to the changes between 1.5.2 and 1.6
1984--------------------------------------------
1985
1986The 1.6 NEWS file can't be changed after the release is done, so here
1987is some late-breaking news:
1988
1989New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1990and changes to getlocale() and setlocale().
1991
1992The new module is now enabled per default.
1993
1994It is not true that the encodings codecs cannot be used for normal
1995strings: the string.encode() (which is also present on 8-bit strings
1996!) allows using them for 8-bit strings too, e.g. to convert files from
1997cp1252 (Windows) to latin-1 or vice-versa.
1998
1999Japanese codecs are available from Tamito KAJIYAMA:
2000http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2001
2002
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002003======================================================================