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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
Guido van Rossum10315822001-05-01 20:54:30 +000087- Dictionary objects now support the "in" operator: "x in dict" means
88 the same as dict.has_key(x).
89
90- Iterators were added; this is a generalized way of providing values
91 to a for loop. See PEP 234. There's a new built-in function iter()
92 to return an iterator. There's a new protocol to get the next value
93 from an iterator using the next() method (in Python) or the
94 tp_iternext slot (in C). There's a new protocol to get iterators
95 using the __iter__() method (in Python) or the tp_iter slot (in C).
96 Iterating (i.e. a for loop) over a dictionary generates its keys.
97 Iterating over a file generates its lines.
98
Tim Petersf553f892001-05-01 20:45:31 +000099- The following functions were generalized to work nicely with iterator
100 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000101 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000102 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
103 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000104 join() method of strings
105 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000106 'x in y' and 'x not in y' (PySequence_Contains() in C API)
107 operator.countOf() (PySequence_Count() in C API)
Tim Peters75f8e352001-05-05 11:33:43 +0000108
Tim Petersd85e1022001-05-11 21:51:48 +0000109- Accessing module attributes is significantly faster (for example,
110 random.random or os.path or yourPythonModule.yourAttribute).
111
Tim Peterse63415e2001-05-08 04:38:29 +0000112- Comparing dictionary objects via == and != is faster, and now works even
113 if the keys and values don't support comparisons other than ==.
114
Tim Peters95bf9392001-05-10 08:32:44 +0000115- Comparing dictionaries in ways other than == and != is slower: there were
116 insecurities in the dict comparison implementation that could cause Python
117 to crash if the element comparison routines for the dict keys and/or
118 values mutated the dicts. Making the code bulletproof slowed it down.
119
Tim Peterseb28ef22001-06-02 05:27:19 +0000120- Collisions in dicts are resolved via a new approach, which can help
121 dramatically in bad cases. For example, looking up every key in a dict
122 d with d.keys() = [i << 16 for i in range(20000)] is approximately 500x
123 faster now. Thanks to Christian Tismer for pointing out the cause and
124 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000125
Tim Petersa814db52001-05-14 07:05:58 +0000126Library
127
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000128- A new function fnmatch.filter to filter lists of file names was added.
129
Barry Warsawffd674d2001-05-22 16:00:10 +0000130- calendar.py uses month and day names based on the current locale.
131
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000132- strop is now *really* obsolete (this was announced before with 1.6),
133 and issues DeprecationWarning when used (except for the four items
134 that are still imported into string.py).
135
Tim Petersa814db52001-05-14 07:05:58 +0000136- Cookie.py now sorts key+value pairs by key in output strings.
137
138- pprint.isrecursive(object) didn't correctly identify recursive objects.
139 Now it does.
140
Tim Peters95b3f782001-05-14 18:39:41 +0000141- pprint functions now much faster for large containers (tuple, list, dict).
142
Tim Peters7b9542a2001-06-10 23:40:19 +0000143- New 'q' and 'Q' format codes in the struct module, corresponding to C
144 types "long long" and "unsigned long long" (on Windows, __int64). In
145 native mode, these can be used only when the platform C compiler supports
146 these types (when HAVE_LONG_LONG is #define'd by the Python config
147 process), and then they inherit the sizes and alignments of the C types.
148 XXX TODO In standard mode, 'q' and 'Q' are supported on all platforms, and
149 XXX TODO are 8-byte integral types.
150
Tim Petersa814db52001-05-14 07:05:58 +0000151Tests
152
153- New test_mutants.py runs dict comparisons where the key and value
154 comparison operators mutute the dicts randomly during comparison. This
155 rapidly causes Python to crash under earlier releases (not for the faint
156 of heart: it can also cause Win9x to freeze or reboot!).
157
158- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000159 pprint.isreadable() return sensible results. Also verifies that simple
160 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000161
Tim Peters58e0a8c2001-05-14 22:32:33 +0000162New platforms
163
164- Python should compile and run out of the box using the Borland C
165 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000166
Tim Peters4324aa32001-05-28 22:30:08 +0000167C API
168
169- Removed the unused last_is_sticky argument from the internal
170 _PyTuple_Resize(). If this affects you, you were cheating.
171
172
Guido van Rossumffe13be2001-04-16 18:46:45 +0000173What's New in Python 2.1 (final)?
174=================================
175
176We only changed a few things since the last release candidate, all in
177Python library code:
178
179- A bug in the locale module was fixed that affected locales which
180 define no grouping for numeric formatting.
181
182- A few bugs in the weakref module's implementations of weak
183 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
184 and the test suite was updated to check for these bugs.
185
186- An old bug in the os.path.walk() function (introduced in Python
187 2.0!) was fixed: a non-existent file would cause an exception
188 instead of being ignored.
189
190- Fixed a few bugs in the new symtable module found by Neil Norwitz's
191 PyChecker.
192
193
Guido van Rossum5b08f132001-04-16 02:05:23 +0000194What's New in Python 2.1c2?
195===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000196
Guido van Rossum5b08f132001-04-16 02:05:23 +0000197A flurry of small changes, and one showstopper fixed in the nick of
198time made it necessary to release another release candidate. The list
199here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000200
Guido van Rossum5b08f132001-04-16 02:05:23 +0000201Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000202
Guido van Rossum5b08f132001-04-16 02:05:23 +0000203- Tim discovered a nasty bug in the dictionary code, caused by
204 PyDict_Next() calling dict_resize(), and the GC code's use of
205 PyDict_Next() violating an assumption in dict_items(). This was
206 fixed with considerable amounts of band-aid, but the net effect is a
207 saner and more robust implementation.
208
209- Made a bunch of symbols static that were accidentally global.
210
211Build and Ports
212
213- The setup.py script didn't check for a new enough version of zlib
214 (1.1.3 is needed). Now it does.
215
216- Changed "make clean" target to also remove shared libraries.
217
218- Added a more general warning about the SGI Irix optimizer to README.
219
220Library
221
222- Fix a bug in urllib.basejoin("http://host", "../file.html") which
223 omitted the slash between host and file.html.
224
225- The mailbox module's _Mailbox class contained a completely broken
226 and undocumented seek() method. Ripped it out.
227
228- Fixed a bunch of typos in various library modules (urllib2, smtpd,
229 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
230
231- Fixed a few last-minute bugs in unittest.
232
233Extensions
234
235- Reverted the patch to the OpenSSL code in socketmodule.c to support
236 RAND_status() and the EGD, and the subsequent patch that tried to
237 fix it for pre-0.9.5 versions; the problem with the patch is that on
238 some systems it issues a warning whenever socket is imported, and
239 that's unacceptable.
240
241Tests
242
243- Fixed the pickle tests to work with "import test.test_pickle".
244
245- Tweaked test_locale.py to actually run the test Windows.
246
247- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
248 not "wb" (which is not a valid mode at all).
249
250- Fix pstats browser crashes. Import readline if it exists to make
251 the user interface nicer.
252
253- Add "import thread" to the top of test modules that import the
254 threading module (test_asynchat and test_threadedtempfile). This
255 prevents test failures caused by a broken threading module resulting
256 from a previously caught failed import.
257
258- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
259 needed on some platforms (e.g. Solaris 8) when the tests are run
260 twice in succession.
261
262- Skip rather than fail test_sunaudiodev if no audio device is found.
263
264
265What's New in Python 2.1c1?
266===========================
267
268This list was significantly updated when 2.1c2 was released; the 2.1c1
269release didn't mention most changes that were actually part of 2.1c1:
270
271Legal
272
273- Copyright was assigned to the Python Software Foundation (PSF) and a
274 PSF license (very similar to the CNRI license) was added.
275
276- The CNRI copyright notice was updated to include 2001.
277
278Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000279
Guido van Rossumc9932722001-04-12 02:31:27 +0000280- After a public outcry, assignment to __debug__ is no longer illegal;
281 instead, a warning is issued. It will become illegal in 2.2.
282
Guido van Rossum5b08f132001-04-16 02:05:23 +0000283- Fixed a core dump with "%#x" % 0, and changed the semantics so that
284 "%#x" now always prepends "0x", even if the value is zero.
285
286- Fixed some nits in the bytecode compiler.
287
288- Fixed core dumps when calling certain kinds of non-functions.
289
290- Fixed various core dumps caused by reference count bugs.
291
292Build and Ports
293
294- Use INSTALL_SCRIPT to install script files.
295
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000296- New port: SCO Unixware 7, by Billy G. Allie.
297
Guido van Rossum5b08f132001-04-16 02:05:23 +0000298- Updated RISCOS port.
299
300- Updated BeOS port and notes.
301
302- Various other porting problems resolved.
303
304Library
305
306- The TERMIOS and SOCKET modules are now truly obsolete and
307 unnecessary. Their symbols are incorporated in the termios and
308 socket modules.
309
310- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
311 better tests for pickling.
312
313- threading: make Condition.wait() robust against KeyboardInterrupt.
314
315- zipfile: add support to zipfile to support opening an archive
316 represented by an open file rather than a file name. Fix bug where
317 the archive was not properly closed. Fixed a bug in this bugfix
318 where flush() was called for a read-only file.
319
320- imputil: added an uninstall() method to the ImportManager.
321
322- Canvas: fixed bugs in lower() and tkraise() methods.
323
324- SocketServer: API change (added overridable close_request() method)
325 so that the TCP server can explicitly close the request.
326
327- pstats: Eric Raymond added a simple interactive statistics browser,
328 invoked when the module is run as a script.
329
330- locale: fixed a problem in format().
331
332- webbrowser: made it work when the BROWSER environment variable has a
333 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
334 KDE 2. Fixed some other nits.
335
336- unittest: changes to allow using a different exception than
337 AssertionError, and added a few more function aliases. Some other
338 small changes.
339
340- urllib, urllib2: fixed redirect problems and a coupleof other nits.
341
342- asynchat: fixed a critical bug in asynchat that slipped through the
343 2.1b2 release. Fixed another rare bug.
344
345- Fix some unqualified except: clauses (always a bad code example).
346
347XML
348
349- pyexpat: new API get_version_string().
350
351- Fixed some minidom bugs.
352
353Extensions
354
355- Fixed a core dump in _weakref. Removed the weakref.mapping()
356 function (it adds nothing to the API).
357
358- Rationalized the use of header files in the readline module, to make
359 it compile (albeit with some warnings) with the very recent readline
360 4.2, without breaking for earlier versions.
361
362- Hopefully fixed a buffering problem in linuxaudiodev.
363
364- Attempted a fix to make the OpenSSL support in the socket module
365 work again with pre-0.9.5 versions of OpenSSL.
366
367Tests
368
369- Added a test case for asynchat and asyncore.
370
371- Removed coupling between tests where one test failing could break
372 another.
373
374Tools
375
376- Ping added an interactive help browser to pydoc, fixed some nits
377 in the rest of the pydoc code, and added some features to his
378 inspect module.
379
380- An updated python-mode.el version 4.1 which integrates Ken
381 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
382 much nicer in XEmacs and Emacs. When stepping through your program
383 with pdb, in either the shell window or the *Python* window, the
384 source file and line will be tracked by an arrow. Very cool!
385
386- IDLE: syntax warnings in interactive mode are changed into errors.
387
388- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000389 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000390
391- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000392
Barry Warsaw11e89c72001-04-11 20:37:57 +0000393
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000394What's New in Python 2.1 beta 2?
395================================
396
Guido van Rossum053ae352001-03-22 14:17:21 +0000397(Unlisted are many fixed bugs, more documentation, etc.)
398
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000399Core language, builtins, and interpreter
400
Guido van Rossum053ae352001-03-22 14:17:21 +0000401- The nested scopes work (enabled by "from __future__ import
402 nested_scopes") is completed; in particular, the future now extends
403 into code executed through exec, eval() and execfile(), and into the
404 interactive interpreter.
405
406- When calling a base class method (e.g. BaseClass.__init__(self)),
407 this is now allowed even if self is not strictly spoken a class
408 instance (e.g. when using metaclasses or the Don Beaudry hook).
409
410- Slice objects are now comparable but not hashable; this prevents
411 dict[:] from being accepted but meaningless.
412
413- Complex division is now calculated using less braindead algorithms.
414 This doesn't change semantics except it's more likely to give useful
415 results in extreme cases. Complex repr() now uses full precision
416 like float repr().
417
418- sgmllib.py now calls handle_decl() for simple <!...> declarations.
419
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000420- It is illegal to assign to the name __debug__, which is set when the
421 interpreter starts. It is effectively a compile-time constant.
422
423- A warning will be issued if a global statement for a variable
424 follows a use or assignment of that variable.
425
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000426Standard library
427
Guido van Rossum053ae352001-03-22 14:17:21 +0000428- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
429 inspired by JUnit), is now part of the standard library. You now
430 have a choice of two testing frameworks: unittest requires you to
431 write testcases as separate code, doctest gathers them from
432 docstrings. Both approaches have their advantages and
433 disadvantages.
434
435- A new module Tix was added, which wraps the Tix extension library
436 for Tk. With that module, it is not necessary to statically link
437 Tix with _tkinter, since Tix will be loaded with Tcl's "package
438 require" command. See Demo/tix/.
439
440- tzparse.py is now obsolete.
441
442- In gzip.py, the seek() and tell() methods are removed -- they were
443 non-functional anyway, and it's better if callers can test for their
444 existence with hasattr().
445
446Python/C API
447
448- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
449 that's already in the dictionary during a PyDict_Next() iteration.
450 This used to fail occasionally when a dictionary resize operation
451 could be triggered that would rehash all the keys. All other
452 modifications to the dictionary are still off-limits during a
453 PyDict_Next() iteration!
454
455- New extended APIs related to passing compiler variables around.
456
457- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
458 implement isinstance() and issubclass().
459
460- Py_BuildValue() now has a "D" conversion to create a Python complex
461 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000462
Fred Drake4e262a92001-03-22 18:26:47 +0000463- Extensions types which support weak references must now set the
464 field allocated for the weak reference machinery to NULL themselves;
465 this is done to avoid the cost of checking each object for having a
466 weakly referencable type in PyObject_INIT(), since most types are
467 not weakly referencable.
468
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000469- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
470 free variables and cell variables to and from the frame's f_locals.
471
472- Variants of several functions defined in pythonrun.h have been added
473 to support the nested_scopes future statement. The variants all end
474 in Flags and take an extra argument, a PyCompilerFlags *; examples:
475 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
476 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000477 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000478
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000479Distutils
480
481- the sdist command now writes a PKG-INFO file, as described in PEP 241,
482 into the release tree.
483
Tim Peters0e57abf2001-05-02 07:39:38 +0000484- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000485 (an uninstaller, more customization of the installer's display)
486
487- from Jack Jansen: added Mac-specific code to generate a dialog for
488 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000489 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000490 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000491
492- added 'platforms' and 'keywords' to the set of metadata that can be
493 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000494
495- applied patches from Jason Tishler to make the compiler class work with
496 Cygwin.
497
498
Tim Peters2fe289a2001-03-01 22:19:38 +0000499What's New in Python 2.1 beta 1?
500================================
Tim Petersd66595f2001-02-04 03:09:53 +0000501
502Core language, builtins, and interpreter
503
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000504- Following an outcry from the community about the amount of code
505 broken by the nested scopes feature introduced in 2.1a2, we decided
506 to make this feature optional, and to wait until Python 2.2 (or at
507 least 6 months) to make it standard. The option can be enabled on a
508 per-module basis by adding "from __future__ import nested_scopes" at
509 the beginning of a module (before any other statements, but after
510 comments and an optional docstring). See PEP 236 (Back to the
511 __future__) for a description of the __future__ statement. PEP 227
512 (Statically Nested Scopes) has been updated to reflect this change,
513 and to clarify the semantics in a number of endcases.
514
515- The nested scopes code, when enabled, has been hardened, and most
516 bugs and memory leaks in it have been fixed.
517
518- Compile-time warnings are now generated for a number of conditions
519 that will break or change in meaning when nested scopes are enabled:
520
521 - Using "from...import *" or "exec" without in-clause in a function
522 scope that also defines a lambda or nested function with one or
523 more free (non-local) variables. The presence of the import* or
524 bare exec makes it impossible for the compiler to determine the
525 exact set of local variables in the outer scope, which makes it
526 impossible to determine the bindings for free variables in the
527 inner scope. To avoid the warning about import *, change it into
528 an import of explicitly name object, or move the import* statement
529 to the global scope; to avoid the warning about bare exec, use
530 exec...in... (a good idea anyway -- there's a possibility that
531 bare exec will be deprecated in the future).
532
533 - Use of a global variable in a nested scope with the same name as a
534 local variable in a surrounding scope. This will change in
535 meaning with nested scopes: the name in the inner scope will
536 reference the variable in the outer scope rather than the global
537 of the same name. To avoid the warning, either rename the outer
538 variable, or use a global statement in the inner function.
539
Neil Schemenauera35c6882001-02-27 04:45:05 +0000540- An optional object allocator has been included. This allocator is
541 optimized for Python objects and should be faster and use less memory
542 than the standard system allocator. It is not enabled by default
543 because of possible thread safety problems. The allocator is only
544 protected by the Python interpreter lock and it is possible that some
545 extension modules require a thread safe allocator. The object
546 allocator can be enabled by providing the "--with-pymalloc" option to
547 configure.
548
Tim Petersd66595f2001-02-04 03:09:53 +0000549Standard library
550
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000551- pyexpat now detects the expat version if expat.h defines it. A
552 number of additional handlers are provided, which are only available
553 since expat 1.95. In addition, the methods SetParamEntityParsing and
554 GetInputContext of Parser objects are available with 1.95.x
555 only. Parser objects now provide the ordered_attributes and
556 specified_attributes attributes. A new module expat.model was added,
557 which offers a number of additional constants if 1.95.x is used.
558
559- xml.dom offers the new functions registerDOMImplementation and
560 getDOMImplementation.
561
562- xml.dom.minidom offers a toprettyxml method. A number of DOM
563 conformance issues have been resolved. In particular, Element now
564 has an hasAttributes method, and the handling of namespaces was
565 improved.
566
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000567- Ka-Ping Yee contributed two new modules: inspect.py, a module for
568 getting information about live Python code, and pydoc.py, a module
569 for interactively converting docstrings to HTML or text.
570 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000571 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000572 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
573 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000574
Tim Peters1eff7962001-03-01 02:31:33 +0000575- New library module difflib.py, primarily packaging the SequenceMatcher
576 class at the heart of the popular ndiff.py file-comparison tool.
577
578- doctest.py (a framework for verifying Python code examples in docstrings)
579 is now part of the std library.
580
Tim Petersd66595f2001-02-04 03:09:53 +0000581Windows changes
582
Guido van Rossume3955a82001-03-02 14:05:59 +0000583- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
584 small GUI that lets you browse the module docstrings using your
585 default web browser.
586
Tim Peters1eff7962001-03-01 02:31:33 +0000587- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
588 Platforms) is implemented. See
589
590 http://python.sourceforge.net/peps/pep-0235.html
591
592 for full details, especially the "Current Lower-Left Semantics" section.
593 The new Windows import rules are simpler than before:
594
595 A. If the PYTHONCASEOK environment variable exists, same as
596 before: silently accept the first case-insensitive match of any
597 kind; raise ImportError if none found.
598
599 B. Else search sys.path for the first case-sensitive match; raise
600 ImportError if none found.
601
602 The same rules have been implented on other platforms with case-
603 insensitive but case-preserving filesystems too (including Cygwin, and
604 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000605
Tim Peters25a9ce32001-02-19 07:06:36 +0000606- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
607 what it's supposed to do (and does do under NT and 2000) via direct
608 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000609 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000610 all Win9x systems before.
611
Tim Peters1eff7962001-03-01 02:31:33 +0000612- Build: Subproject _test (effectively) renamed to _testcapi.
613
Tim Peters2fe289a2001-03-01 22:19:38 +0000614New platforms
615
616- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
617 Thanks to Steven Majewski!
618
619- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
620 Tishler!
621
Guido van Rossum9089b272001-03-02 06:49:50 +0000622- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
623 Schwertberger! See RISCOS/README for more information -- it seems
624 that because of the bizarre filename conventions on RISCOS, no port
625 to that platform is easy. Note that the new variable os.endsep is
626 silently supported in order to make life easier on this platform,
627 but we don't advertise it because it's not worth for most folks to
628 care about RISCOS portability.
629
Tim Peters25a9ce32001-02-19 07:06:36 +0000630
Tim Petersd7b5e882001-01-25 03:36:26 +0000631What's New in Python 2.1 alpha 2?
632=================================
Tim Peters40ead762001-01-27 05:35:26 +0000633
Tim Petersd7b5e882001-01-25 03:36:26 +0000634Core language, builtins, and interpreter
635
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000636- Scopes nest. If a name is used in a function or class, but is not
637 local, the definition in the nearest enclosing function scope will
638 be used. One consequence of this change is that lambda statements
639 could reference variables in the namespaces where the lambda is
640 defined. In some unusual cases, this change will break code.
641
642 In all previous version of Python, names were resolved in exactly
643 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000644 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000645 function A is defined within a function B, the names bound in B are
646 not visible in A. The new rules make names bound in B visible in A,
647 unless A contains a name binding that hides the binding in B.
648
649 Section 4.1 of the reference manual describes the new scoping rules
650 in detail. The test script in Lib/test/test_scope.py demonstrates
651 some of the effects of the change.
652
653 The new rules will cause existing code to break if it defines nested
654 functions where an outer function has local variables with the same
655 name as globals or builtins used by the inner function. Example:
656
657 def munge(str):
658 def helper(x):
659 return str(x)
660 if type(str) != type(''):
661 str = helper(str)
662 return str.strip()
663
664 Under the old rules, the name str in helper() is bound to the
665 builtin function str(). Under the new rules, it will be bound to
666 the argument named str and an error will occur when helper() is
667 called.
668
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000669- The compiler will report a SyntaxError if "from ... import *" occurs
670 in a function or class scope. The language reference has documented
671 that this case is illegal, but the compiler never checked for it.
672 The recent introduction of nested scope makes the meaning of this
673 form of name binding ambiguous. In a future release, the compiler
674 may allow this form when there is no possibility of ambiguity.
675
Tim Peters40ead762001-01-27 05:35:26 +0000676- repr(string) is easier to read, now using hex escapes instead of octal,
677 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
678
679 >>> "\texample \r\n" + chr(0) + chr(255)
680 '\texample \r\n\x00\xff' # in 2.1
681 '\011example \015\012\000\377' # in 2.0
682
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000683- Functions are now compared and hashed by identity, not by value, since
684 the func_code attribute is writable.
685
Fred Drakefb9d7122001-02-01 20:00:40 +0000686- Weak references (PEP 205) have been added. This involves a few
687 changes in the core, an extension module (_weakref), and a Python
688 module (weakref). The weakref module is the public interface. It
689 includes support for "explicit" weak references, proxy objects, and
690 mappings with weakly held values.
691
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000692- A 'continue' statement can now appear in a try block within the body
693 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000694 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000695
Tim Petersd7b5e882001-01-25 03:36:26 +0000696Standard library
697
Barry Warsaw30dbd142001-01-31 22:14:01 +0000698- mailbox.py now has a new class, PortableUnixMailbox which is
699 identical to UnixMailbox but uses a more portable scheme for
700 determining From_ separators. Also, the constructors for all the
701 classes in this module have a new optional `factory' argument, which
702 is a callable used when new message classes must be instantiated by
703 the next() method.
704
Tim Petersd7b5e882001-01-25 03:36:26 +0000705- random.py is now self-contained, and offers all the functionality of
706 the now-deprecated whrandom.py. See the docs for details. random.py
707 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000708 and restoring the internal state of the generator; and jumpahead(n),
709 for quickly forcing the internal state to be the same as if n calls to
710 random() had been made. The latter is particularly useful for multi-
711 threaded programs, creating one instance of the random.Random() class for
712 each thread, then using .jumpahead() to force each instance to use a
713 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000714
Tim Peters0de88fc2001-02-01 04:59:18 +0000715- random.py's seed() function is new. For bit-for-bit compatibility with
716 prior releases, use the whseed function instead. The new seed function
717 addresses two problems: (1) The old function couldn't produce more than
718 about 2**24 distinct internal states; the new one about 2**45 (the best
719 that can be done in the Wichmann-Hill generator). (2) The old function
720 sometimes produced identical internal states when passed distinct
721 integers, and there was no simple way to predict when that would happen;
722 the new one guarantees to produce distinct internal states for all
723 arguments in [0, 27814431486576L).
724
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000725- The socket module now supports raw packets on Linux. The socket
726 family is AF_PACKET.
727
Tim Peters9ea17ac2001-02-02 05:57:15 +0000728- test_capi.py is a start at running tests of the Python C API. The tests
729 are implemented by the new Modules/_testmodule.c.
730
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000731- A new extension module, _symtable, provides provisional access to the
732 internal symbol table used by the Python compiler. A higher-level
733 interface will be added on top of _symtable in a future release.
734
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000735- Removed the obsolete soundex module.
736
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000737- xml.dom.minidom now uses the standard DOM exceptions. Node supports
738 the isSameNode method; NamedNodeMap the get method.
739
740- xml.sax.expatreader supports the lexical handler property; it
741 generates comment, startCDATA, and endCDATA events.
742
Tim Petersee826f82001-01-31 19:39:44 +0000743Windows changes
744
745- Build procedure: the zlib project is built in a different way that
746 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000747 the zlib binary used. See PCbuild\readme.txt for details. Your old
748 zlib-related directories can be deleted; you'll need to download fresh
749 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000750
Tim Peters9ea17ac2001-02-02 05:57:15 +0000751- Build: New subproject _test for the benefit of test_capi.py (see above).
752
Tim Petersb16c56f2001-02-02 21:24:51 +0000753- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
754 interface to some Python compiler internals).
755
756- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000757 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000758
Tim Petersa3a3a032000-11-30 05:22:44 +0000759What's New in Python 2.1 alpha 1?
760=================================
761
762Core language, builtins, and interpreter
763
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000764- There is a new Unicode companion to the PyObject_Str() API
765 called PyObject_Unicode(). It behaves in the same way as the
766 former, but assures that the returned value is an Unicode object
767 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000768
Guido van Rossumf98eda02001-01-17 15:54:45 +0000769- The comparison operators support "rich comparison overloading" (PEP
770 207). C extension types can provide a rich comparison function in
771 the new tp_richcompare slot in the type object. The cmp() function
772 and the C function PyObject_Compare() first try the new rich
773 comparison operators before trying the old 3-way comparison. There
774 is also a new C API PyObject_RichCompare() (which also falls back on
775 the old 3-way comparison, but does not constrain the outcome of the
776 rich comparison to a Boolean result).
777
778 The rich comparison function takes two objects (at least one of
779 which is guaranteed to have the type that provided the function) and
780 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
781 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
782 object, which may be NotImplemented (in which case the tp_compare
783 slot function is used as a fallback, if defined).
784
785 Classes can overload individual comparison operators by defining one
786 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000787 __ge__. There are no explicit "reflected argument" versions of
788 these; instead, __lt__ and __gt__ are each other's reflection,
789 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
790 reflection (similar at the C level). No other implications are
791 made; in particular, Python does not assume that == is the Boolean
792 inverse of !=, or that < is the Boolean inverse of >=. This makes
793 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000794
795 Classes or types that want to implement (in)equality tests but not
796 the ordering operators (i.e. unordered types) should implement ==
797 and !=, and raise an error for the ordering operators.
798
Guido van Rossuma88479f2001-01-18 14:28:08 +0000799 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000800 Boolean; e.g. a matrix type might want to return a matrix of bits
801 for A < B, giving elementwise comparisons. Such types should ensure
802 that any interpretation of their value in a Boolean context raises
803 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
804 at the C level) to always raise an exception.
805
Guido van Rossuma88479f2001-01-18 14:28:08 +0000806- Complex numbers use rich comparisons to define == and != but raise
807 an exception for <, <=, > and >=. Unfortunately, this also means
808 that cmp() of two complex numbers raises an exception when the two
809 numbers differ. Since it is not mathematically meaningful to compare
810 complex numbers except for equality, I hope that this doesn't break
811 too much code.
812
Tim Peters3389f192001-02-18 08:48:49 +0000813- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000814 not defined by the language, other than that it's arbitrary but
815 consistent (see the Reference Manual). An implementation detail changed
816 in 2.1a1 such that None now compares less than any other object. Code
817 relying on this new behavior (like code that relied on the previous
818 behavior) does so at its own risk.
819
Barry Warsaw573b5412001-01-15 20:43:18 +0000820- Functions and methods now support getting and setting arbitrarily
821 named attributes (PEP 232). Functions have a new __dict__
822 (a.k.a. func_dict) which hold the function attributes. Methods get
823 and set attributes on their underlying im_func. It is a TypeError
824 to set an attribute on a bound method.
825
Guido van Rossum051e3352001-01-15 19:11:10 +0000826- The xrange() object implementation has been improved so that
827 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
828 limitation that in this case len(xrange(sys.maxint)) can't be
829 calculated, but the common idiom "for i in xrange(sys.maxint)" will
830 work fine as long as the index i doesn't actually reach 2**31.
831 (Python uses regular ints for sequence and string indices; fixing
832 that is much more work.)
833
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000834- Two changes to from...import:
835
Guido van Rossumba381232001-02-03 15:06:40 +0000836 1) "from M import X" now works even if (after loading module M)
837 sys.modules['M'] is not a real module; it's basically a getattr()
838 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000839
840 2) "from M import *" now looks for M.__all__ to decide which names to
841 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
842 filters out names starting with '_' as before. Whether or not
843 __all__ exists, there's no restriction on the type of M.
844
Guido van Rossumf61f1662001-01-10 20:13:55 +0000845- File objects have a new method, xreadlines(). This is the fastest
846 way to iterate over all lines in a file:
847
848 for line in file.xreadlines():
849 ...do something to line...
850
851 See the xreadlines module (mentioned below) for how to do this for
852 other file-like objects.
853
854- Even if you don't use file.xreadlines(), you may expect a speedup on
855 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000856 quite a bit in platform-specific ways: on systems (like Linux) that
857 support flockfile(), getc_unlocked(), and funlockfile(), those are
858 used by default. On systems (like Windows) without getc_unlocked(),
859 a complicated (but still thread-safe) method using fgets() is used by
860 default.
861
Tim Petersd52269b2001-01-25 06:23:18 +0000862 You can force use of the fgets() method by #define'ing
863 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000864 getc_unlocked()).
865
Tim Petersd52269b2001-01-25 06:23:18 +0000866 You can force fgets() not to be used by #define'ing
867 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000868 test_bufio.py fails -- and let us know if it does!).
869
870- In addition, the fileinput module, while still slower than the other
871 methods on most platforms, has been sped up too, by using
872 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000873
874- Support for run-time warnings has been added, including a new
875 command line option (-W) to specify the disposition of warnings.
876 See the description of the warnings module below.
877
878- Extensive changes have been made to the coercion code. This mostly
879 affects extension modules (which can now implement mixed-type
880 numerical operators without having to use coercion), but
881 occasionally, in boundary cases the coercion semantics have changed
882 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000883 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000884 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000885 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000886
Guido van Rossumf98eda02001-01-17 15:54:45 +0000887- In connection with the coercion changes, a new built-in singleton
888 object, NotImplemented is defined. This can be returned for
889 operations that wish to indicate they are not implemented for a
890 particular combination of arguments. From C, this is
891 Py_NotImplemented.
892
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000893- The interpreter accepts now bytecode files on the command line even
894 if they do not have a .pyc or .pyo extension. On Linux, after executing
895
Martin v. Löwise214baa2001-02-04 22:37:56 +0000896import imp,sys,string
897magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
898reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
899open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000900
901 any byte code file can be used as an executable (i.e. as an argument
902 to execve(2)).
903
Tim Peters9940b802000-12-01 07:59:35 +0000904- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000905 character. In 1.6 and earlier, they never produced a sign,
906 and raised an error if the value of the long was too large
907 to fit in a Python int. In 2.0, they produced a sign if and
908 only if too large to fit in an int. This was inconsistent
909 across platforms (because the size of an int varies across
910 platforms), and inconsistent with hex() and oct(). Example:
911
912 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000913 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000914 'ffffffbe' # in 2.0 and before, on 32-bit machines
915 >>> hex(-0x42L)
916 '-0x42L' # in all versions of Python
917
Tim Peters9940b802000-12-01 07:59:35 +0000918 The behavior of %d formats for negative Python longs remains
919 the same as in 2.0 (although in 1.6 and before, they raised
920 an error if the long didn't fit in a Python int).
921
922 %u formats don't make sense for Python longs, but are allowed
923 and treated the same as %d in 2.1. In 2.0, a negative long
924 formatted via %u produced a sign if and only if too large to
925 fit in an int. In 1.6 and earlier, a negative long formatted
926 via %u raised an error if it was too big to fit in an int.
927
Guido van Rossum3661d392000-12-12 22:10:31 +0000928- Dictionary objects have an odd new method, popitem(). This removes
929 an arbitrary item from the dictionary and returns it (in the form of
930 a (key, value) pair). This can be useful for algorithms that use a
931 dictionary as a bag of "to do" items and repeatedly need to pick one
932 item. Such algorithms normally end up running in quadratic time;
933 using popitem() they can usually be made to run in linear time.
934
Tim Peters36cdad12000-12-29 02:06:45 +0000935Standard library
936
Thomas Woutersfe385252001-01-19 23:16:56 +0000937- In the time module, the time argument to the functions strftime,
938 localtime, gmtime, asctime and ctime is now optional, defaulting to
939 the current time (in the local timezone).
940
Guido van Rossumda91f222001-01-15 16:36:08 +0000941- The ftplib module now defaults to passive mode, which is deemed a
942 more useful default given that clients are often inside firewalls
943 these days. Note that this could break if ftplib is used to connect
944 to a *server* that is inside a firewall, from outside; this is
945 expected to be a very rare situation. To fix that, you can call
946 ftp.set_pasv(0).
947
Martin v. Löwis10a27872001-01-13 09:54:41 +0000948- The module site now treats .pth files not only for path configuration,
949 but also supports extensions to the initialization code: Lines starting
950 with import are executed.
951
Guido van Rossumf61f1662001-01-10 20:13:55 +0000952- There's a new module, warnings, which implements a mechanism for
953 issuing and filtering warnings. There are some new built-in
954 exceptions that serve as warning categories, and a new command line
955 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
956 turns warnings into errors). warnings.warn(message[, category])
957 issues a warning message; this can also be called from C as
958 PyErr_Warn(category, message).
959
960- A new module xreadlines was added. This exports a single factory
961 function, xreadlines(). The intention is that this code is the
962 absolutely fastest way to iterate over all lines in an open
963 file(-like) object:
964
965 import xreadlines
966 for line in xreadlines.xreadlines(file):
967 ...do something to line...
968
969 This is equivalent to the previous the speed record holder using
970 file.readlines(sizehint). Note that if file is a real file object
971 (as opposed to a file-like object), this is equivalent:
972
973 for line in file.xreadlines():
974 ...do something to line...
975
Tim Peters36cdad12000-12-29 02:06:45 +0000976- The bisect module has new functions bisect_left, insort_left,
977 bisect_right and insort_right. The old names bisect and insort
978 are now aliases for bisect_right and insort_right. XXX_right
979 and XXX_left methods differ in what happens when the new element
980 compares equal to one or more elements already in the list: the
981 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000982 right. Code that doesn't care where equal elements end up should
983 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000984
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000985- The new curses.panel module wraps the panel library that forms part
986 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
987
Guido van Rossumf61f1662001-01-10 20:13:55 +0000988- The SocketServer module now sets the allow_reuse_address flag by
989 default in the TCPServer class.
990
991- A new function, sys._getframe(), returns the stack frame pointer of
992 the caller. This is intended only as a building block for
993 higher-level mechanisms such as string interpolation.
994
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000995- The pyexpat module supports a number of new handlers, which are
996 available only in expat 1.2. If invocation of a callback fails, it
997 will report an additional frame in the traceback. Parser objects
998 participate now in garbage collection. If expat reports an unknown
999 encoding, pyexpat will try to use a Python codec; that works only
1000 for single-byte charsets. The parser type objects is exposed as
1001 XMLParserObject.
1002
1003- xml.dom now offers standard definitions for symbolic node type and
1004 exception code constants, and a hierarchy of DOM exceptions. minidom
1005 was adjusted to use them.
1006
1007- The conformance of xml.dom.minidom to the DOM specification was
1008 improved. It detects a number of additional error cases; the
1009 previous/next relationship works even when the tree is modified;
1010 Node supports the normalize() method; NamedNodeMap, DocumentType and
1011 DOMImplementation classes were added; Element supports the
1012 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1013 method.
1014
Guido van Rossumf61f1662001-01-10 20:13:55 +00001015Build issues
1016
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001017- For Unix (and Unix-compatible) builds, configuration and building of
1018 extension modules is now greatly automated. Rather than having to
1019 edit the Modules/Setup file to indicate which modules should be
1020 built and where their include files and libraries are, a
1021 distutils-based setup.py script now takes care of building most
1022 extension modules. All extension modules built this way are built
1023 as shared libraries. Only a few modules that must be linked
1024 statically are still listed in the Setup file; you won't need to
1025 edit their configuration.
1026
1027- Python should now build out of the box on Cygwin. If it doesn't,
1028 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001029
1030- Python now always uses its own (renamed) implementation of getopt()
1031 -- there's too much variation among C library getopt()
1032 implementations.
1033
1034- C++ compilers are better supported; the CXX macro is always set to a
1035 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001036
Tim Petersd92dfe02000-12-12 01:18:41 +00001037Windows changes
1038
1039- select module: By default under Windows, a select() call
1040 can specify no more than 64 sockets. Python now boosts
1041 this Microsoft default to 512. If you need even more than
1042 that, see the MS docs (you'll need to #define FD_SETSIZE
1043 and recompile Python from source).
1044
Guido van Rossumf61f1662001-01-10 20:13:55 +00001045- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1046 subdirectory is no more!
1047
Tim Petersa3a3a032000-11-30 05:22:44 +00001048
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001049What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001050=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001051
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001052Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001053changes are in the file HISTORY. If you are making the jump directly
1054from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1055HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001056
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001057Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1058the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1059http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001060
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001061--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001062
1063======================================================================
1064
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001065What's new in 2.0 (since release candidate 1)?
1066==============================================
1067
1068Standard library
1069
1070- The copy_reg module was modified to clarify its intended use: to
1071 register pickle support for extension types, not for classes.
1072 pickle() will raise a TypeError if it is passed a class.
1073
1074- Fixed a bug in gettext's "normalize and expand" code that prevented
1075 it from finding an existing .mo file.
1076
1077- Restored support for HTTP/0.9 servers in httplib.
1078
Tim Peters989b7b92000-10-16 20:24:53 +00001079- The math module was changed to stop raising OverflowError in case of
1080 underflow, and return 0 instead in underflow cases. Whether Python
1081 used to raise OverflowError in case of underflow was platform-
1082 dependent (it did when the platform math library set errno to ERANGE
1083 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001084
1085- Fixed a bug in StringIO that occurred when the file position was not
1086 at the end of the file and write() was called with enough data to
1087 extend past the end of the file.
1088
1089- Fixed a bug that caused Tkinter error messages to get lost on
1090 Windows. The bug was fixed by replacing direct use of
1091 interp->result with Tcl_GetStringResult(interp).
1092
1093- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1094 redirect response.
1095
1096- Several changes were made to distutils: Some debugging code was
1097 removed from util. Fixed the installer used when an external zip
1098 program (like WinZip) is not found; the source code for this
1099 installer is in Misc/distutils. check_lib() was modified to behave
1100 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1101 test for whether installed modules are on sys.path was changed to
1102 use both normcase() and normpath().
1103
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001104- Several minor bugs were fixed in the xml package (the minidom,
1105 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001106
1107- The regression test driver (regrtest.py) behavior when invoked with
1108 -l changed: It now reports a count of objects that are recognized as
1109 garbage but not freed by the garbage collector.
1110
Tim Peters989b7b92000-10-16 20:24:53 +00001111- The regression test for the math module was changed to test
1112 exceptional behavior when the test is run in verbose mode. Python
1113 cannot yet guarantee consistent exception behavior across platforms,
1114 so the exception part of test_math is run only in verbose mode, and
1115 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001116
1117Internals
1118
1119- PyOS_CheckStack() has been disabled on Win64, where it caused
1120 test_sre to fail.
1121
1122Build issues
1123
1124- Changed compiler flags, so that gcc is always invoked with -Wall and
1125 -Wstrict-prototypes. Users compiling Python with GCC should see
1126 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001127 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001128 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001129
Tim Petersa3a3a032000-11-30 05:22:44 +00001130- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001131
1132Tools and other miscellany
1133
1134- The compiler in Tools/compiler was updated to support the new
1135 language features introduced in 2.0: extended print statement, list
1136 comprehensions, and augmented assignments. The new compiler should
1137 also be backwards compatible with Python 1.5.2; the compiler will
1138 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001139 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001140
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001141What's new in 2.0 release candidate 1 (since beta 2)?
1142=====================================================
1143
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001144What is release candidate 1?
1145
1146We believe that release candidate 1 will fix all known bugs that we
1147intend to fix for the 2.0 final release. This release should be a bit
1148more stable than the previous betas. We would like to see even more
1149widespread testing before the final release, so we are producing this
1150release candidate. The final release will be exactly the same unless
1151any show-stopping (or brown bag) bugs are found by testers of the
1152release candidate.
1153
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001154All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001155to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001156
1157Core language, builtins, and interpreter
1158
1159- A bug that caused crashes when __coerce__ was used with augmented
1160 assignment, e.g. +=, was fixed.
1161
1162- Raise ZeroDivisionError when raising zero to a negative number,
1163 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1164 power operator and the result of math.pow(0.0, -2.0) will vary by
1165 platform. On Linux, it raises a ValueError.
1166
1167- A bug in Unicode string interpolation was fixed that occasionally
1168 caused errors with formats including "%%". For example, the
1169 following expression "%% %s" % u"abc" no longer raises a TypeError.
1170
1171- Compilation of deeply nested expressions raises MemoryError instead
1172 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1173
1174- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1175 rendering them useless. They are now written in binary mode again.
1176
1177Standard library
1178
1179- Keyword arguments are now accepted for most pattern and match object
1180 methods in SRE, the standard regular expression engine.
1181
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001182- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001183 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001184
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001185- Several bugs in the Unicode handling and error handling in _tkinter
1186 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001187
1188- Fix memory management errors in Merge() and Tkapp_Call() routines.
1189
1190- Several changes were made to cStringIO to make it compatible with
1191 the file-like object interface and with StringIO. If operations are
1192 performed on a closed object, an exception is raised. The truncate
1193 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001194 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001195
1196- There were many changes made to the linuxaudiodev module and its
1197 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001198 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001199
1200 Note that this module is named poorly, because it should work
1201 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001202 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001203
1204 The module now raises exceptions when errors occur instead of
1205 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1206 audio) and defines a getptr() method that calls the
1207 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1208
1209- The library_version attribute, introduced in an earlier beta, was
1210 removed because it can not be supported with early versions of the C
1211 readline library, which provides no way to determine the version at
1212 compile-time.
1213
1214- The binascii module is now enabled on Win64.
1215
Tim Peters46446d62000-10-09 21:19:31 +00001216- tokenize.py no longer suffers "recursion depth" errors when parsing
1217 programs with very long string literals.
1218
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001219Internals
1220
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001221- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001222 which is called when the interpreter starts up to determine where
1223 the standard library is installed. These vulnerabilities affect all
1224 previous versions of Python and can be exploited by setting very
1225 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1226 setuid Python script, although use of the wrapper in
1227 Misc/setuid-prog.c will eliminate the vulnerability.
1228
1229- Fixed garbage collection bugs in instance creation that were
1230 triggered when errors occurred during initialization. The solution,
1231 applied in cPickle and in PyInstance_New(), is to call
1232 PyObject_GC_Init() after the initialization of the object's
1233 container attributes is complete.
1234
1235- pyexpat adds definitions of PyModule_AddStringConstant and
1236 PyModule_AddObject if the Python version is less than 2.0, which
1237 provides compatibility with PyXML on Python 1.5.2.
1238
1239- If the platform has a bogus definition for LONG_BIT (the number of
1240 bits in a long), an error will be reported at compile time.
1241
1242- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1243 collection crashes and possibly other, unreported crashes.
1244
1245- Fixed a memory leak in _PyUnicode_Fini().
1246
1247Build issues
1248
1249- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001250 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001251 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001252
1253- The mmap.PAGESIZE constant is now initialized using sysconf when
1254 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1255
1256- The md5 file should now compile on all platforms.
1257
1258- The select module now compiles on platforms that do not define
1259 POLLRDNORM and related constants.
1260
1261- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001262 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001263
Jeremy Hylton10921202000-10-09 18:34:12 +00001264- BeOS: A number of changes were made to the build and installation
1265 process. ar-fake now operates on a directory of object files.
1266 dl_export.h is gone, and its macros now appear on the mwcc command
1267 line during build on PPC BeOS.
1268
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001269- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001270 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001271
1272- Cygwin: Support for shared libraries, Tkinter, and sockets.
1273
1274- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1275
1276Tools and other miscellany
1277
1278- Removed debugging prints from main used with freeze.
1279
Tim Peters46446d62000-10-09 21:19:31 +00001280- IDLE auto-indent no longer crashes when it encounters Unicode
1281 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001282
1283What's new in 2.0 beta 2 (since beta 1)?
1284========================================
1285
1286Core language, builtins, and interpreter
1287
Tim Peters482c0212000-09-26 06:33:09 +00001288- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001289 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001290
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001291- Add -h and -V command line options to print the usage message and
1292 Python version number and exit immediately.
1293
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001294- eval() and exec accept Unicode objects as code parameters.
1295
1296- getattr() and setattr() now also accept Unicode objects for the
1297 attribute name, which are converted to strings using the default
1298 encoding before lookup.
1299
1300- Multiplication on string and Unicode now does proper bounds
1301 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1302 string is too long."
1303
1304- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001305 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001306
Jeremy Hylton1b618592000-09-26 05:32:36 +00001307
1308Standard library and extensions
1309
Guido van Rossum5b08f132001-04-16 02:05:23 +00001310- socket module: the OpenSSL code now adds support for RAND_status()
1311 and EGD (Entropy Gathering Device).
1312
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001313- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001314 argument checking; it still takes no arguments.
1315
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001316- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001317
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001318- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001319
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001320- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001321
1322- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001323 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001324
1325- copy: Copy Unicode objects atomically.
1326
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001327- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001328
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001329- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001330
Fred Drake67233bc2000-09-26 16:40:27 +00001331- dbm: Add get() and setdefault() methods to dbm object. Add constant
1332 `library' to module that names the library used. Added doc strings
1333 and method names to error messages. Uses configure to determine
1334 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1335 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001336
1337- distutils: Update to version 0.9.3.
1338
1339- dl: Add several dl.RTLD_ constants.
1340
1341- fpectl: Now supported on FreeBSD.
1342
1343- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1344 found by the collector will be saved in gc.garbage. This is useful
1345 for debugging a program that creates reference cycles.
1346
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001347- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001348 of HTTP class. Do not close socket on zero-length response. Do not
1349 crash when server sends invalid content-length header.
1350
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001351- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001352
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001353- marshal: When reading a short, sign-extend on platforms where shorts
1354 are bigger than 16 bits. When reading a long, repair the unportable
1355 sign extension that was being done for 64-bit machines. (It assumed
1356 that signed right shift sign-extends.)
1357
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001358- operator: Add contains(), invert(), __invert__() as aliases for
1359 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001360
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001361- os: Add support for popen2() and popen3() on all platforms where
1362 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001363
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001364- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001365 clicking on a file in Explorer (or passing the file name to the
1366 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001367
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001368- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001369 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001370
1371- pickle: Now raises ValueError when an invalid pickle that contains
1372 a non-string repr where a string repr was expected. This behavior
1373 matches cPickle.
1374
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001375- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001376
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001377- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001378
1379- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001380 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001381 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001382
1383- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001384 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001385
1386- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001387 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001388 few cycles during startup since the first call to
1389 setdefaultencoding() will initialize the codec registry and the
1390 encodings package.
1391
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001392- socket: Support for size hint in readlines() method of object returned
1393 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001394
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001395- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001396 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001397 is followed by whitespace.
1398
Tim Petersa3a3a032000-11-30 05:22:44 +00001399- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001400
1401- struct: Check ranges for bytes and shorts.
1402
1403- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001404 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001405
1406- Tkinter: Image objects are now guaranteed to have unique ids. Set
1407 event.delta to zero if Tk version doesn't support mousewheel.
1408 Removed some debugging prints.
1409
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001410- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001411
Fred Drake67233bc2000-09-26 16:40:27 +00001412- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001413 which works around a bug in Norton AntiVirus 2000 that leads directly
1414 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001415
1416- xml: New version detection code allows PyXML to override standard
1417 XML package if PyXML version is greater than 0.6.1.
1418
Fred Drake64bb3802000-09-26 16:21:35 +00001419- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1420 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1421 tree only for nodes which are sufficiently interesting to a specific
1422 application. Does not provide the HTML-specific extensions. Still
1423 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001424
Fred Drake64bb3802000-09-26 16:21:35 +00001425- xml.sax: SAX 2 support for Python, including all the handler
1426 interfaces needed to process XML 1.0 compliant XML. Some
1427 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001428
Fred Drake64bb3802000-09-26 16:21:35 +00001429- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1430 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001431
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001432
Jeremy Hylton1b618592000-09-26 05:32:36 +00001433C API
1434
1435- Add three new convenience functions for module initialization --
1436 PyModule_AddObject(), PyModule_AddIntConstant(), and
1437 PyModule_AddStringConstant().
1438
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001439- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001440 removed and add #error to Python.h if NULL isn't defined after
1441 #include of stdio.h.
1442
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001443- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001444 backwards compatibility (at the source level) with old extensions.
1445
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001446- A wrapper API was added for signal() and sigaction(). Instead of
1447 either function, always use PyOS_getsig() to get a signal handler
1448 and PyOS_setsig() to set one. A new convenience typedef
1449 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001450
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001451- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001452 internal data buffer and size of a string object -- or the default
1453 encoded version of a Unicode object.
1454
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001455- PyString_Size() and PyString_AsString() accept Unicode objects.
1456
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001457- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001458 exists). INT_MAX and LONG_MAX will always be defined, even if
1459 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001460
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001461- PyFloat_FromString takes a second argument, pend, that was
1462 effectively useless. It is now officially useless but preserved for
1463 backwards compatibility. If the pend argument is not NULL, *pend is
1464 set to NULL.
1465
1466- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1467 for the attribute name. See note on getattr() above.
1468
1469- A few bug fixes to argument processing for Unicode.
1470 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1471 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1472 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001473 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001474
1475- Py_BuildValue accepts B format (for bgen-generated code).
1476
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001477
Jeremy Hylton1b618592000-09-26 05:32:36 +00001478Internals
1479
1480- On Unix, fix code for finding Python installation directory so that
1481 it works when argv[0] is a relative path.
1482
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001483- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001484 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001485 rather than by generating a copy of the object.
1486
Tim Peters482c0212000-09-26 06:33:09 +00001487- Several of the internal Unicode tables are much smaller now, and
1488 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001489
Jeremy Hylton97693b02000-09-26 17:42:51 +00001490- In the garbage collector: Fixed bug in collection of tuples. Fixed
1491 bug that caused some instances to be removed from the container set
1492 while they were still live. Fixed parsing in gc.set_debug() for
1493 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001494
1495- Fixed refcount problem in instance deallocation that only occurred
1496 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1497
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001498- On Windows, getpythonregpath is now protected against null data in
1499 registry key.
1500
1501- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001502 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001503
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001504
Jeremy Hylton1b618592000-09-26 05:32:36 +00001505Build and platform-specific issues
1506
1507- Better support of GNU Pth via --with-pth configure option.
1508
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001509- Python/C API now properly exposed to dynamically-loaded extension
1510 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001511
1512- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1513 Don't define MS_SYNC to be zero when it is undefined. Added missing
1514 prototypes in posixmodule.c.
1515
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001516- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001517 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001518
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001519- Fix largefile support on older NetBSD systems and OpenBSD by adding
1520 define for TELL64.
1521
1522
1523Tools and other miscellany
1524
1525- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1526
1527- freeze: The modulefinder now works with 2.0 opcodes.
1528
Tim Petersa3a3a032000-11-30 05:22:44 +00001529- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001530 Move hackery of sys.argv until after the Tk instance has been
1531 created, which allows the application-specific Tkinter
1532 initialization to be executed if present; also pass an explicit
1533 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001534
Jeremy Hylton1b618592000-09-26 05:32:36 +00001535
1536What's new in 2.0 beta 1?
1537=========================
1538
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001539Source Incompatibilities
1540------------------------
1541
1542None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1543such as single-argument append(), connect() and bind(), and changes to
1544str(long) and repr(float).
1545
1546
1547Binary Incompatibilities
1548------------------------
1549
1550- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1551with Python 2.0; these extensions will have to be rebuilt for Python
15522.0.
1553
1554- On Windows, attempting to import a third party extension built for
1555Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1556can do about this. Check your PYTHONPATH environment variable!
1557
1558- Python bytecode files (*.pyc and *.pyo) are not compatible between
1559releases.
1560
1561
1562Overview of Changes Since 1.6
1563-----------------------------
1564
1565There are many new modules (including brand new XML support through
1566the xml package, and i18n support through the gettext module); a list
1567of all new modules is included below. Lots of bugs have been fixed.
1568
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001569The process for making major new changes to the language has changed
1570since Python 1.6. Enhancements must now be documented by a Python
1571Enhancement Proposal (PEP) before they can be accepted.
1572
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001573There are several important syntax enhancements, described in more
1574detail below:
1575
1576 - Augmented assignment, e.g. x += 1
1577
1578 - List comprehensions, e.g. [x**2 for x in range(10)]
1579
1580 - Extended import statement, e.g. import Module as Name
1581
1582 - Extended print statement, e.g. print >> file, "Hello"
1583
1584Other important changes:
1585
1586 - Optional collection of cyclical garbage
1587
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001588Python Enhancement Proposal (PEP)
1589---------------------------------
1590
1591PEP stands for Python Enhancement Proposal. A PEP is a design
1592document providing information to the Python community, or describing
1593a new feature for Python. The PEP should provide a concise technical
1594specification of the feature and a rationale for the feature.
1595
1596We intend PEPs to be the primary mechanisms for proposing new
1597features, for collecting community input on an issue, and for
1598documenting the design decisions that have gone into Python. The PEP
1599author is responsible for building consensus within the community and
1600documenting dissenting opinions.
1601
1602The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001603
1604Augmented Assignment
1605--------------------
1606
1607This must have been the most-requested feature of the past years!
1608Eleven new assignment operators were added:
1609
Guido van Rossume905e952000-09-05 12:42:46 +00001610 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001611
1612For example,
1613
1614 A += B
1615
1616is similar to
1617
1618 A = A + B
1619
1620except that A is evaluated only once (relevant when A is something
1621like dict[index].attr).
1622
1623However, if A is a mutable object, A may be modified in place. Thus,
1624if A is a number or a string, A += B has the same effect as A = A+B
1625(except A is only evaluated once); but if a is a list, A += B has the
1626same effect as A.extend(B)!
1627
1628Classes and built-in object types can override the new operators in
1629order to implement the in-place behavior; the not-in-place behavior is
1630used automatically as a fallback when an object doesn't implement the
1631in-place behavior. For classes, the method name is derived from the
1632method name for the corresponding not-in-place operator by inserting
1633an 'i' in front of the name, e.g. __iadd__ implements in-place
1634__add__.
1635
1636Augmented assignment was implemented by Thomas Wouters.
1637
1638
1639List Comprehensions
1640-------------------
1641
1642This is a flexible new notation for lists whose elements are computed
1643from another list (or lists). The simplest form is:
1644
1645 [<expression> for <variable> in <sequence>]
1646
Guido van Rossum56db0952000-09-06 23:34:25 +00001647For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001648This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001649
1650You can also add a condition:
1651
1652 [<expression> for <variable> in <sequence> if <condition>]
1653
1654For example, [w for w in words if w == w.lower()] would yield the list
1655of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001656than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001657
1658You can also have nested for loops and more than one 'if' clause. For
1659example, here's a function that flattens a sequence of sequences::
1660
1661 def flatten(seq):
1662 return [x for subseq in seq for x in subseq]
1663
1664 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1665
1666This prints
1667
1668 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1669
1670List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001671Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001672
1673
1674Extended Import Statement
1675-------------------------
1676
1677Many people have asked for a way to import a module under a different
1678name. This can be accomplished like this:
1679
1680 import foo
1681 bar = foo
1682 del foo
1683
1684but this common idiom gets old quickly. A simple extension of the
1685import statement now allows this to be written as follows:
1686
1687 import foo as bar
1688
1689There's also a variant for 'from ... import':
1690
1691 from foo import bar as spam
1692
1693This also works with packages; e.g. you can write this:
1694
1695 import test.regrtest as regrtest
1696
1697Note that 'as' is not a new keyword -- it is recognized only in this
1698context (this is only possible because the syntax for the import
1699statement doesn't involve expressions).
1700
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001701Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001702
1703
1704Extended Print Statement
1705------------------------
1706
1707Easily the most controversial new feature, this extension to the print
1708statement adds an option to make the output go to a different file
1709than the default sys.stdout.
1710
1711For example, to write an error message to sys.stderr, you can now
1712write:
1713
1714 print >> sys.stderr, "Error: bad dog!"
1715
1716As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001717evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001718
1719 print >> None, "Hello world"
1720
1721is equivalent to
1722
1723 print "Hello world"
1724
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001725Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001726
1727
1728Optional Collection of Cyclical Garbage
1729---------------------------------------
1730
1731Python is now equipped with a garbage collector that can hunt down
1732cyclical references between Python objects. It's no replacement for
1733reference counting; in fact, it depends on the reference counts being
1734correct, and decides that a set of objects belong to a cycle if all
1735their reference counts can be accounted for from their references to
1736each other. This devious scheme was first proposed by Eric Tiedemann,
1737and brought to implementation by Neil Schemenauer.
1738
1739There's a module "gc" that lets you control some parameters of the
1740garbage collection. There's also an option to the configure script
1741that lets you enable or disable the garbage collection. In 2.0b1,
1742it's on by default, so that we (hopefully) can collect decent user
1743experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001744performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001745off by default in the final 2.0 release.
1746
1747
1748Smaller Changes
1749---------------
1750
1751A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1752map(None, seq1, seq2, ...) when the sequences have the same length;
1753i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1754the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001755zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001756
1757sys.version_info is a tuple (major, minor, micro, level, serial).
1758
1759Dictionaries have an odd new method, setdefault(key, default).
1760dict.setdefault(key, default) returns dict[key] if it exists; if not,
1761it sets dict[key] to default and returns that value. Thus:
1762
1763 dict.setdefault(key, []).append(item)
1764
1765does the same work as this common idiom:
1766
1767 if not dict.has_key(key):
1768 dict[key] = []
1769 dict[key].append(item)
1770
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001771There are two new variants of SyntaxError that are raised for
1772indentation-related errors: IndentationError and TabError.
1773
1774Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1775escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001776
1777The limits on the size of expressions and file in Python source code
1778have been raised from 2**16 to 2**32. Previous versions of Python
1779were limited because the maximum argument size the Python VM accepted
1780was 2**16. This limited the size of object constructor expressions,
1781e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1782limit was raised thanks to a patch by Charles Waldman that effectively
1783fixes the problem. It is now much more likely that you will be
1784limited by available memory than by an arbitrary limit in Python.
1785
1786The interpreter's maximum recursion depth can be modified by Python
1787programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1788limit is the maximum number of recursive calls that can be made by
1789Python code. The limit exists to prevent infinite recursion from
1790overflowing the C stack and causing a core dump. The default value is
17911000. The maximum safe value for a particular platform can be found
1792by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001793
1794New Modules and Packages
1795------------------------
1796
1797atexit - for registering functions to be called when Python exits.
1798
1799imputil - Greg Stein's alternative API for writing custom import
1800hooks.
1801
1802pyexpat - an interface to the Expat XML parser, contributed by Paul
1803Prescod.
1804
1805xml - a new package with XML support code organized (so far) in three
1806subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1807would fill a volume. There's a special feature whereby a
1808user-installed package named _xmlplus overrides the standard
1809xmlpackage; this is intended to give the XML SIG a hook to distribute
1810backwards-compatible updates to the standard xml package.
1811
1812webbrowser - a platform-independent API to launch a web browser.
1813
1814
Guido van Rossume905e952000-09-05 12:42:46 +00001815Changed Modules
1816---------------
1817
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001818array -- new methods for array objects: count, extend, index, pop, and
1819remove
1820
1821binascii -- new functions b2a_hex and a2b_hex that convert between
1822binary data and its hex representation
1823
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001824calendar -- Many new functions that support features including control
1825over which day of the week is the first day, returning strings instead
1826of printing them. Also new symbolic constants for days of week,
1827e.g. MONDAY, ..., SUNDAY.
1828
1829cgi -- FieldStorage objects have a getvalue method that works like a
1830dictionary's get method and returns the value attribute of the object.
1831
1832ConfigParser -- The parser object has new methods has_option,
1833remove_section, remove_option, set, and write. They allow the module
1834to be used for writing config files as well as reading them.
1835
1836ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001837optionally support the RFC 959 REST command.
1838
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001839gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001840
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001841httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1842the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001843
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001844locale -- implement getdefaultlocale for Win32 and Macintosh
1845
1846marshal -- no longer dumps core when marshaling deeply nested or
1847recursive data structures
1848
1849os -- new functions isatty, seteuid, setegid, setreuid, setregid
1850
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001851os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1852support under Unix.
1853
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001854os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001855
1856os.path -- fix semantics of os.path.commonprefix
1857
1858smtplib -- support for sending very long messages
1859
1860socket -- new function getfqdn()
1861
1862readline -- new functions to read, write and truncate history files.
1863The readline section of the library reference manual contains an
1864example.
1865
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001866select -- add interface to poll system call
1867
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001868shutil -- new copyfileobj function
1869
1870SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1871HTTP server.
1872
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001873Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001874
1875urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001876e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001877
1878whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001879
1880
1881Obsolete Modules
1882----------------
1883
1884None. However note that 1.6 made a whole slew of modules obsolete:
1885stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1886poly, zmod, strop, util, whatsound.
1887
1888
1889Changed, New, Obsolete Tools
1890----------------------------
1891
Tim Peters8b092332000-09-05 20:15:25 +00001892None.
Guido van Rossume905e952000-09-05 12:42:46 +00001893
1894
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001895C-level Changes
1896---------------
1897
1898Several cleanup jobs were carried out throughout the source code.
1899
1900All C code was converted to ANSI C; we got rid of all uses of the
1901Py_PROTO() macro, which makes the header files a lot more readable.
1902
1903Most of the portability hacks were moved to a new header file,
1904pyport.h; several other new header files were added and some old
1905header files were removed, in an attempt to create a more rational set
1906of header files. (Few of these ever need to be included explicitly;
1907they are all included by Python.h.)
1908
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001909Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001910and Win64, especially for the new Intel Itanium processor. Mick also
1911added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001912
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001913The C APIs to return an object's size have been update to consistently
1914use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1915previous versions, the abstract interfaces used PyXXX_Length and the
1916concrete interfaces used PyXXX_Size. The old names,
1917e.g. PyObject_Length, are still available for backwards compatibility
1918at the API level, but are deprecated.
1919
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001920The PyOS_CheckStack function has been implemented on Windows by
1921Fredrik Lundh. It prevents Python from failing with a stack overflow
1922on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001923
1924The GC changes resulted in creation of two new slots on object,
1925tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001926the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001927
1928The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001929C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001930
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001931PyErr_Format has been updated to automatically calculate the size of
1932the buffer needed to hold the formatted result string. This change
1933prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001934
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001935New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001936
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001937PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1938that are the same as their non-Ex counterparts except they take an
1939extra flag argument that tells them to close the file when done.
1940
1941XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001942
Tim Peters8b092332000-09-05 20:15:25 +00001943
1944Windows Changes
1945---------------
1946
1947New popen2/popen3/peopen4 in os module (see Changed Modules above).
1948
1949os.popen is much more usable on Windows 95 and 98. See Microsoft
1950Knowledge Base article Q150956. The Win9x workaround described there
1951is implemented by the new w9xpopen.exe helper in the root of your
1952Python installation. Note that Python uses this internally; it is not
1953a standalone program.
1954
1955Administrator privileges are no longer required to install Python
1956on Windows NT or Windows 2000. If you have administrator privileges,
1957Python's registry info will be written under HKEY_LOCAL_MACHINE.
1958Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001959under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001960uses of Python, but will prevent some advanced uses from working
1961(for example, running a Python script as an NT service, or possibly
1962from CGI).
1963
1964[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1965installer; instead, it installs the needed Tcl/Tk files directly in the
1966Python directory. If you already have a Tcl/Tk installation, this
1967wastes some disk space (about 4 Megs) but avoids problems with
1968conflicting Tcl/Tk installations, and makes it much easier for Python
1969to ensure that Tcl/Tk can find all its files.
1970
1971[This was new in 1.6] The Windows installer now installs by default in
1972\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1973
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001974
1975Updates to the changes between 1.5.2 and 1.6
1976--------------------------------------------
1977
1978The 1.6 NEWS file can't be changed after the release is done, so here
1979is some late-breaking news:
1980
1981New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1982and changes to getlocale() and setlocale().
1983
1984The new module is now enabled per default.
1985
1986It is not true that the encodings codecs cannot be used for normal
1987strings: the string.encode() (which is also present on 8-bit strings
1988!) allows using them for 8-bit strings too, e.g. to convert files from
1989cp1252 (Windows) to latin-1 or vice-versa.
1990
1991Japanese codecs are available from Tamito KAJIYAMA:
1992http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1993
1994
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001995======================================================================