blob: 3a15837fc99d37b1587a614d72c2790bd9f25847 [file] [log] [blame]
Tim Petersf553f892001-05-01 20:45:31 +00001What's New in Python 2.2a0?
2===========================
3
4Core
Tim Petersa814db52001-05-14 07:05:58 +00005
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00006- The UTF-16 codec was modified to be more RFC compliant. It will now
7 only remove BOM characters at the start of the string and then
8 only if running in native mode (UTF-16-LE and -BE won't remove a
9 leading BMO character).
10
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000011- Strings now have a new method .decode() to complement the already
12 existing .encode() method. These two methods provide direct access
13 to the corresponding decoders and encoders of the registered codecs.
14
15 To enhance the usability of the .encode() method, the special
16 casing of Unicode object return values was dropped (Unicode objects
17 were auto-magically converted to string using the default encoding).
18
19 Both methods will now return whatever the codec in charge of the
20 requested encoding returns as object, e.g. Unicode codecs will
21 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
22 will return u"äöü"). This enables codec writer to create codecs
23 for various simple to use conversions.
24
25 New codecs were added to demonstrate these new features (the .encode()
26 and .decode() columns indicate the type of the returned objects):
27
28 Name | .encode() | .decode() | Description
29 ----------------------------------------------------------------------
30 uu | string | string | UU codec (e.g. for email)
31 base64 | string | string | base64 codec
32 zlib | string | string | zlib compression
33 hex | string | string | 2-byte hex codec
34 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
35
Mark Hammond2a0af792001-05-14 03:09:36 +000036- Some operating systems now support the concept of a default Unicode
37 encoding for file system operations. Notably, Windows supports 'mbcs'
38 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +000039 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000040 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000041
42 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000043 functions that return filenames (such as os.listdir()) to return Python
44 string objects pre-encoded using the default file system encoding for
45 the platform. As this encoding is likely to be different from Python's
46 default encoding, converting this name to a Unicode object before passing
47 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000048 would attempt to use its default encoding (generally ASCII) rather than
49 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000050
Tim Petersa814db52001-05-14 07:05:58 +000051 In general, this change simply removes surprises when working with
52 Unicode and the file system, making these operations work as you expect,
53 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +000054 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +000055
Tim Peters61dff2b2001-05-08 15:43:37 +000056- Float (and complex) literals in source code were evaluated to full
57 precision only when running from a .py file; the same code loaded from a
58 .pyc (or .pyo) file could suffer numeric differences starting at about the
59 12th significant decimal digit. For example, on a machine with IEEE-754
60 floating arithmetic,
61
62 x = 9007199254740992.0
63 print long(x)
64
65 printed 9007199254740992 if run directly from .py, but 9007199254740000
66 if from a compiled (.pyc or .pyo) file. This was due to marshal using
67 str(float) instead of repr(float) when building code objects. marshal
68 now uses repr(float) instead, which should reproduce floats to full
69 machine precision (assuming the platform C float<->string I/O conversion
70 functions are of good quality).
71
72 This may cause floating-point results to change in some cases, and
73 usually for the better, but may also cause numerically unstable
74 algorithms to break.
75
Tim Peters2f228e72001-05-13 00:19:31 +000076- The implementation of dicts suffers fewer collisions, which has speed
77 benefits. However, the order in which dict entries appear in dict.keys(),
78 dict.values() and dict.items() may differ from previous releases for a
79 given dict. Nothing is defined about this order, so no program should
80 rely on it. Nevertheless, it's easy to write test cases that rely on the
81 order by accident, typically because of printing the str() or repr() of a
82 dict to an "expected results" file. See Lib/test/test_support.py's new
83 sortdict(dict) function for a simple way to display a dict in sorted
84 order.
85
Guido van Rossum10315822001-05-01 20:54:30 +000086- Dictionary objects now support the "in" operator: "x in dict" means
87 the same as dict.has_key(x).
88
89- Iterators were added; this is a generalized way of providing values
90 to a for loop. See PEP 234. There's a new built-in function iter()
91 to return an iterator. There's a new protocol to get the next value
92 from an iterator using the next() method (in Python) or the
93 tp_iternext slot (in C). There's a new protocol to get iterators
94 using the __iter__() method (in Python) or the tp_iter slot (in C).
95 Iterating (i.e. a for loop) over a dictionary generates its keys.
96 Iterating over a file generates its lines.
97
Tim Petersf553f892001-05-01 20:45:31 +000098- The following functions were generalized to work nicely with iterator
99 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000100 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000101 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
102 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000103 join() method of strings
104 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000105 'x in y' and 'x not in y' (PySequence_Contains() in C API)
106 operator.countOf() (PySequence_Count() in C API)
Tim Peters75f8e352001-05-05 11:33:43 +0000107
Tim Petersd85e1022001-05-11 21:51:48 +0000108- Accessing module attributes is significantly faster (for example,
109 random.random or os.path or yourPythonModule.yourAttribute).
110
Tim Peterse63415e2001-05-08 04:38:29 +0000111- Comparing dictionary objects via == and != is faster, and now works even
112 if the keys and values don't support comparisons other than ==.
113
Tim Peters95bf9392001-05-10 08:32:44 +0000114- Comparing dictionaries in ways other than == and != is slower: there were
115 insecurities in the dict comparison implementation that could cause Python
116 to crash if the element comparison routines for the dict keys and/or
117 values mutated the dicts. Making the code bulletproof slowed it down.
118
Tim Petersa814db52001-05-14 07:05:58 +0000119Library
120
Barry Warsawffd674d2001-05-22 16:00:10 +0000121- calendar.py uses month and day names based on the current locale.
122
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000123- strop is now *really* obsolete (this was announced before with 1.6),
124 and issues DeprecationWarning when used (except for the four items
125 that are still imported into string.py).
126
Tim Petersa814db52001-05-14 07:05:58 +0000127- Cookie.py now sorts key+value pairs by key in output strings.
128
129- pprint.isrecursive(object) didn't correctly identify recursive objects.
130 Now it does.
131
Tim Peters95b3f782001-05-14 18:39:41 +0000132- pprint functions now much faster for large containers (tuple, list, dict).
133
Tim Petersa814db52001-05-14 07:05:58 +0000134Tests
135
136- New test_mutants.py runs dict comparisons where the key and value
137 comparison operators mutute the dicts randomly during comparison. This
138 rapidly causes Python to crash under earlier releases (not for the faint
139 of heart: it can also cause Win9x to freeze or reboot!).
140
141- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000142 pprint.isreadable() return sensible results. Also verifies that simple
143 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000144
Tim Peters58e0a8c2001-05-14 22:32:33 +0000145New platforms
146
147- Python should compile and run out of the box using the Borland C
148 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000149
Guido van Rossumffe13be2001-04-16 18:46:45 +0000150What's New in Python 2.1 (final)?
151=================================
152
153We only changed a few things since the last release candidate, all in
154Python library code:
155
156- A bug in the locale module was fixed that affected locales which
157 define no grouping for numeric formatting.
158
159- A few bugs in the weakref module's implementations of weak
160 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
161 and the test suite was updated to check for these bugs.
162
163- An old bug in the os.path.walk() function (introduced in Python
164 2.0!) was fixed: a non-existent file would cause an exception
165 instead of being ignored.
166
167- Fixed a few bugs in the new symtable module found by Neil Norwitz's
168 PyChecker.
169
170
Guido van Rossum5b08f132001-04-16 02:05:23 +0000171What's New in Python 2.1c2?
172===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000173
Guido van Rossum5b08f132001-04-16 02:05:23 +0000174A flurry of small changes, and one showstopper fixed in the nick of
175time made it necessary to release another release candidate. The list
176here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000177
Guido van Rossum5b08f132001-04-16 02:05:23 +0000178Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000179
Guido van Rossum5b08f132001-04-16 02:05:23 +0000180- Tim discovered a nasty bug in the dictionary code, caused by
181 PyDict_Next() calling dict_resize(), and the GC code's use of
182 PyDict_Next() violating an assumption in dict_items(). This was
183 fixed with considerable amounts of band-aid, but the net effect is a
184 saner and more robust implementation.
185
186- Made a bunch of symbols static that were accidentally global.
187
188Build and Ports
189
190- The setup.py script didn't check for a new enough version of zlib
191 (1.1.3 is needed). Now it does.
192
193- Changed "make clean" target to also remove shared libraries.
194
195- Added a more general warning about the SGI Irix optimizer to README.
196
197Library
198
199- Fix a bug in urllib.basejoin("http://host", "../file.html") which
200 omitted the slash between host and file.html.
201
202- The mailbox module's _Mailbox class contained a completely broken
203 and undocumented seek() method. Ripped it out.
204
205- Fixed a bunch of typos in various library modules (urllib2, smtpd,
206 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
207
208- Fixed a few last-minute bugs in unittest.
209
210Extensions
211
212- Reverted the patch to the OpenSSL code in socketmodule.c to support
213 RAND_status() and the EGD, and the subsequent patch that tried to
214 fix it for pre-0.9.5 versions; the problem with the patch is that on
215 some systems it issues a warning whenever socket is imported, and
216 that's unacceptable.
217
218Tests
219
220- Fixed the pickle tests to work with "import test.test_pickle".
221
222- Tweaked test_locale.py to actually run the test Windows.
223
224- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
225 not "wb" (which is not a valid mode at all).
226
227- Fix pstats browser crashes. Import readline if it exists to make
228 the user interface nicer.
229
230- Add "import thread" to the top of test modules that import the
231 threading module (test_asynchat and test_threadedtempfile). This
232 prevents test failures caused by a broken threading module resulting
233 from a previously caught failed import.
234
235- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
236 needed on some platforms (e.g. Solaris 8) when the tests are run
237 twice in succession.
238
239- Skip rather than fail test_sunaudiodev if no audio device is found.
240
241
242What's New in Python 2.1c1?
243===========================
244
245This list was significantly updated when 2.1c2 was released; the 2.1c1
246release didn't mention most changes that were actually part of 2.1c1:
247
248Legal
249
250- Copyright was assigned to the Python Software Foundation (PSF) and a
251 PSF license (very similar to the CNRI license) was added.
252
253- The CNRI copyright notice was updated to include 2001.
254
255Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000256
Guido van Rossumc9932722001-04-12 02:31:27 +0000257- After a public outcry, assignment to __debug__ is no longer illegal;
258 instead, a warning is issued. It will become illegal in 2.2.
259
Guido van Rossum5b08f132001-04-16 02:05:23 +0000260- Fixed a core dump with "%#x" % 0, and changed the semantics so that
261 "%#x" now always prepends "0x", even if the value is zero.
262
263- Fixed some nits in the bytecode compiler.
264
265- Fixed core dumps when calling certain kinds of non-functions.
266
267- Fixed various core dumps caused by reference count bugs.
268
269Build and Ports
270
271- Use INSTALL_SCRIPT to install script files.
272
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000273- New port: SCO Unixware 7, by Billy G. Allie.
274
Guido van Rossum5b08f132001-04-16 02:05:23 +0000275- Updated RISCOS port.
276
277- Updated BeOS port and notes.
278
279- Various other porting problems resolved.
280
281Library
282
283- The TERMIOS and SOCKET modules are now truly obsolete and
284 unnecessary. Their symbols are incorporated in the termios and
285 socket modules.
286
287- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
288 better tests for pickling.
289
290- threading: make Condition.wait() robust against KeyboardInterrupt.
291
292- zipfile: add support to zipfile to support opening an archive
293 represented by an open file rather than a file name. Fix bug where
294 the archive was not properly closed. Fixed a bug in this bugfix
295 where flush() was called for a read-only file.
296
297- imputil: added an uninstall() method to the ImportManager.
298
299- Canvas: fixed bugs in lower() and tkraise() methods.
300
301- SocketServer: API change (added overridable close_request() method)
302 so that the TCP server can explicitly close the request.
303
304- pstats: Eric Raymond added a simple interactive statistics browser,
305 invoked when the module is run as a script.
306
307- locale: fixed a problem in format().
308
309- webbrowser: made it work when the BROWSER environment variable has a
310 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
311 KDE 2. Fixed some other nits.
312
313- unittest: changes to allow using a different exception than
314 AssertionError, and added a few more function aliases. Some other
315 small changes.
316
317- urllib, urllib2: fixed redirect problems and a coupleof other nits.
318
319- asynchat: fixed a critical bug in asynchat that slipped through the
320 2.1b2 release. Fixed another rare bug.
321
322- Fix some unqualified except: clauses (always a bad code example).
323
324XML
325
326- pyexpat: new API get_version_string().
327
328- Fixed some minidom bugs.
329
330Extensions
331
332- Fixed a core dump in _weakref. Removed the weakref.mapping()
333 function (it adds nothing to the API).
334
335- Rationalized the use of header files in the readline module, to make
336 it compile (albeit with some warnings) with the very recent readline
337 4.2, without breaking for earlier versions.
338
339- Hopefully fixed a buffering problem in linuxaudiodev.
340
341- Attempted a fix to make the OpenSSL support in the socket module
342 work again with pre-0.9.5 versions of OpenSSL.
343
344Tests
345
346- Added a test case for asynchat and asyncore.
347
348- Removed coupling between tests where one test failing could break
349 another.
350
351Tools
352
353- Ping added an interactive help browser to pydoc, fixed some nits
354 in the rest of the pydoc code, and added some features to his
355 inspect module.
356
357- An updated python-mode.el version 4.1 which integrates Ken
358 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
359 much nicer in XEmacs and Emacs. When stepping through your program
360 with pdb, in either the shell window or the *Python* window, the
361 source file and line will be tracked by an arrow. Very cool!
362
363- IDLE: syntax warnings in interactive mode are changed into errors.
364
365- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000366 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000367
368- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000369
Barry Warsaw11e89c72001-04-11 20:37:57 +0000370
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000371What's New in Python 2.1 beta 2?
372================================
373
Guido van Rossum053ae352001-03-22 14:17:21 +0000374(Unlisted are many fixed bugs, more documentation, etc.)
375
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000376Core language, builtins, and interpreter
377
Guido van Rossum053ae352001-03-22 14:17:21 +0000378- The nested scopes work (enabled by "from __future__ import
379 nested_scopes") is completed; in particular, the future now extends
380 into code executed through exec, eval() and execfile(), and into the
381 interactive interpreter.
382
383- When calling a base class method (e.g. BaseClass.__init__(self)),
384 this is now allowed even if self is not strictly spoken a class
385 instance (e.g. when using metaclasses or the Don Beaudry hook).
386
387- Slice objects are now comparable but not hashable; this prevents
388 dict[:] from being accepted but meaningless.
389
390- Complex division is now calculated using less braindead algorithms.
391 This doesn't change semantics except it's more likely to give useful
392 results in extreme cases. Complex repr() now uses full precision
393 like float repr().
394
395- sgmllib.py now calls handle_decl() for simple <!...> declarations.
396
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000397- It is illegal to assign to the name __debug__, which is set when the
398 interpreter starts. It is effectively a compile-time constant.
399
400- A warning will be issued if a global statement for a variable
401 follows a use or assignment of that variable.
402
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000403Standard library
404
Guido van Rossum053ae352001-03-22 14:17:21 +0000405- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
406 inspired by JUnit), is now part of the standard library. You now
407 have a choice of two testing frameworks: unittest requires you to
408 write testcases as separate code, doctest gathers them from
409 docstrings. Both approaches have their advantages and
410 disadvantages.
411
412- A new module Tix was added, which wraps the Tix extension library
413 for Tk. With that module, it is not necessary to statically link
414 Tix with _tkinter, since Tix will be loaded with Tcl's "package
415 require" command. See Demo/tix/.
416
417- tzparse.py is now obsolete.
418
419- In gzip.py, the seek() and tell() methods are removed -- they were
420 non-functional anyway, and it's better if callers can test for their
421 existence with hasattr().
422
423Python/C API
424
425- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
426 that's already in the dictionary during a PyDict_Next() iteration.
427 This used to fail occasionally when a dictionary resize operation
428 could be triggered that would rehash all the keys. All other
429 modifications to the dictionary are still off-limits during a
430 PyDict_Next() iteration!
431
432- New extended APIs related to passing compiler variables around.
433
434- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
435 implement isinstance() and issubclass().
436
437- Py_BuildValue() now has a "D" conversion to create a Python complex
438 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000439
Fred Drake4e262a92001-03-22 18:26:47 +0000440- Extensions types which support weak references must now set the
441 field allocated for the weak reference machinery to NULL themselves;
442 this is done to avoid the cost of checking each object for having a
443 weakly referencable type in PyObject_INIT(), since most types are
444 not weakly referencable.
445
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000446- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
447 free variables and cell variables to and from the frame's f_locals.
448
449- Variants of several functions defined in pythonrun.h have been added
450 to support the nested_scopes future statement. The variants all end
451 in Flags and take an extra argument, a PyCompilerFlags *; examples:
452 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
453 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000454 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000455
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000456Distutils
457
458- the sdist command now writes a PKG-INFO file, as described in PEP 241,
459 into the release tree.
460
Tim Peters0e57abf2001-05-02 07:39:38 +0000461- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000462 (an uninstaller, more customization of the installer's display)
463
464- from Jack Jansen: added Mac-specific code to generate a dialog for
465 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000466 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000467 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000468
469- added 'platforms' and 'keywords' to the set of metadata that can be
470 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000471
472- applied patches from Jason Tishler to make the compiler class work with
473 Cygwin.
474
475
Tim Peters2fe289a2001-03-01 22:19:38 +0000476What's New in Python 2.1 beta 1?
477================================
Tim Petersd66595f2001-02-04 03:09:53 +0000478
479Core language, builtins, and interpreter
480
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000481- Following an outcry from the community about the amount of code
482 broken by the nested scopes feature introduced in 2.1a2, we decided
483 to make this feature optional, and to wait until Python 2.2 (or at
484 least 6 months) to make it standard. The option can be enabled on a
485 per-module basis by adding "from __future__ import nested_scopes" at
486 the beginning of a module (before any other statements, but after
487 comments and an optional docstring). See PEP 236 (Back to the
488 __future__) for a description of the __future__ statement. PEP 227
489 (Statically Nested Scopes) has been updated to reflect this change,
490 and to clarify the semantics in a number of endcases.
491
492- The nested scopes code, when enabled, has been hardened, and most
493 bugs and memory leaks in it have been fixed.
494
495- Compile-time warnings are now generated for a number of conditions
496 that will break or change in meaning when nested scopes are enabled:
497
498 - Using "from...import *" or "exec" without in-clause in a function
499 scope that also defines a lambda or nested function with one or
500 more free (non-local) variables. The presence of the import* or
501 bare exec makes it impossible for the compiler to determine the
502 exact set of local variables in the outer scope, which makes it
503 impossible to determine the bindings for free variables in the
504 inner scope. To avoid the warning about import *, change it into
505 an import of explicitly name object, or move the import* statement
506 to the global scope; to avoid the warning about bare exec, use
507 exec...in... (a good idea anyway -- there's a possibility that
508 bare exec will be deprecated in the future).
509
510 - Use of a global variable in a nested scope with the same name as a
511 local variable in a surrounding scope. This will change in
512 meaning with nested scopes: the name in the inner scope will
513 reference the variable in the outer scope rather than the global
514 of the same name. To avoid the warning, either rename the outer
515 variable, or use a global statement in the inner function.
516
Neil Schemenauera35c6882001-02-27 04:45:05 +0000517- An optional object allocator has been included. This allocator is
518 optimized for Python objects and should be faster and use less memory
519 than the standard system allocator. It is not enabled by default
520 because of possible thread safety problems. The allocator is only
521 protected by the Python interpreter lock and it is possible that some
522 extension modules require a thread safe allocator. The object
523 allocator can be enabled by providing the "--with-pymalloc" option to
524 configure.
525
Tim Petersd66595f2001-02-04 03:09:53 +0000526Standard library
527
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000528- pyexpat now detects the expat version if expat.h defines it. A
529 number of additional handlers are provided, which are only available
530 since expat 1.95. In addition, the methods SetParamEntityParsing and
531 GetInputContext of Parser objects are available with 1.95.x
532 only. Parser objects now provide the ordered_attributes and
533 specified_attributes attributes. A new module expat.model was added,
534 which offers a number of additional constants if 1.95.x is used.
535
536- xml.dom offers the new functions registerDOMImplementation and
537 getDOMImplementation.
538
539- xml.dom.minidom offers a toprettyxml method. A number of DOM
540 conformance issues have been resolved. In particular, Element now
541 has an hasAttributes method, and the handling of namespaces was
542 improved.
543
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000544- Ka-Ping Yee contributed two new modules: inspect.py, a module for
545 getting information about live Python code, and pydoc.py, a module
546 for interactively converting docstrings to HTML or text.
547 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000548 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000549 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
550 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000551
Tim Peters1eff7962001-03-01 02:31:33 +0000552- New library module difflib.py, primarily packaging the SequenceMatcher
553 class at the heart of the popular ndiff.py file-comparison tool.
554
555- doctest.py (a framework for verifying Python code examples in docstrings)
556 is now part of the std library.
557
Tim Petersd66595f2001-02-04 03:09:53 +0000558Windows changes
559
Guido van Rossume3955a82001-03-02 14:05:59 +0000560- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
561 small GUI that lets you browse the module docstrings using your
562 default web browser.
563
Tim Peters1eff7962001-03-01 02:31:33 +0000564- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
565 Platforms) is implemented. See
566
567 http://python.sourceforge.net/peps/pep-0235.html
568
569 for full details, especially the "Current Lower-Left Semantics" section.
570 The new Windows import rules are simpler than before:
571
572 A. If the PYTHONCASEOK environment variable exists, same as
573 before: silently accept the first case-insensitive match of any
574 kind; raise ImportError if none found.
575
576 B. Else search sys.path for the first case-sensitive match; raise
577 ImportError if none found.
578
579 The same rules have been implented on other platforms with case-
580 insensitive but case-preserving filesystems too (including Cygwin, and
581 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000582
Tim Peters25a9ce32001-02-19 07:06:36 +0000583- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
584 what it's supposed to do (and does do under NT and 2000) via direct
585 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000586 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000587 all Win9x systems before.
588
Tim Peters1eff7962001-03-01 02:31:33 +0000589- Build: Subproject _test (effectively) renamed to _testcapi.
590
Tim Peters2fe289a2001-03-01 22:19:38 +0000591New platforms
592
593- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
594 Thanks to Steven Majewski!
595
596- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
597 Tishler!
598
Guido van Rossum9089b272001-03-02 06:49:50 +0000599- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
600 Schwertberger! See RISCOS/README for more information -- it seems
601 that because of the bizarre filename conventions on RISCOS, no port
602 to that platform is easy. Note that the new variable os.endsep is
603 silently supported in order to make life easier on this platform,
604 but we don't advertise it because it's not worth for most folks to
605 care about RISCOS portability.
606
Tim Peters25a9ce32001-02-19 07:06:36 +0000607
Tim Petersd7b5e882001-01-25 03:36:26 +0000608What's New in Python 2.1 alpha 2?
609=================================
Tim Peters40ead762001-01-27 05:35:26 +0000610
Tim Petersd7b5e882001-01-25 03:36:26 +0000611Core language, builtins, and interpreter
612
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000613- Scopes nest. If a name is used in a function or class, but is not
614 local, the definition in the nearest enclosing function scope will
615 be used. One consequence of this change is that lambda statements
616 could reference variables in the namespaces where the lambda is
617 defined. In some unusual cases, this change will break code.
618
619 In all previous version of Python, names were resolved in exactly
620 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000621 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000622 function A is defined within a function B, the names bound in B are
623 not visible in A. The new rules make names bound in B visible in A,
624 unless A contains a name binding that hides the binding in B.
625
626 Section 4.1 of the reference manual describes the new scoping rules
627 in detail. The test script in Lib/test/test_scope.py demonstrates
628 some of the effects of the change.
629
630 The new rules will cause existing code to break if it defines nested
631 functions where an outer function has local variables with the same
632 name as globals or builtins used by the inner function. Example:
633
634 def munge(str):
635 def helper(x):
636 return str(x)
637 if type(str) != type(''):
638 str = helper(str)
639 return str.strip()
640
641 Under the old rules, the name str in helper() is bound to the
642 builtin function str(). Under the new rules, it will be bound to
643 the argument named str and an error will occur when helper() is
644 called.
645
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000646- The compiler will report a SyntaxError if "from ... import *" occurs
647 in a function or class scope. The language reference has documented
648 that this case is illegal, but the compiler never checked for it.
649 The recent introduction of nested scope makes the meaning of this
650 form of name binding ambiguous. In a future release, the compiler
651 may allow this form when there is no possibility of ambiguity.
652
Tim Peters40ead762001-01-27 05:35:26 +0000653- repr(string) is easier to read, now using hex escapes instead of octal,
654 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
655
656 >>> "\texample \r\n" + chr(0) + chr(255)
657 '\texample \r\n\x00\xff' # in 2.1
658 '\011example \015\012\000\377' # in 2.0
659
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000660- Functions are now compared and hashed by identity, not by value, since
661 the func_code attribute is writable.
662
Fred Drakefb9d7122001-02-01 20:00:40 +0000663- Weak references (PEP 205) have been added. This involves a few
664 changes in the core, an extension module (_weakref), and a Python
665 module (weakref). The weakref module is the public interface. It
666 includes support for "explicit" weak references, proxy objects, and
667 mappings with weakly held values.
668
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000669- A 'continue' statement can now appear in a try block within the body
670 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000671 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000672
Tim Petersd7b5e882001-01-25 03:36:26 +0000673Standard library
674
Barry Warsaw30dbd142001-01-31 22:14:01 +0000675- mailbox.py now has a new class, PortableUnixMailbox which is
676 identical to UnixMailbox but uses a more portable scheme for
677 determining From_ separators. Also, the constructors for all the
678 classes in this module have a new optional `factory' argument, which
679 is a callable used when new message classes must be instantiated by
680 the next() method.
681
Tim Petersd7b5e882001-01-25 03:36:26 +0000682- random.py is now self-contained, and offers all the functionality of
683 the now-deprecated whrandom.py. See the docs for details. random.py
684 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000685 and restoring the internal state of the generator; and jumpahead(n),
686 for quickly forcing the internal state to be the same as if n calls to
687 random() had been made. The latter is particularly useful for multi-
688 threaded programs, creating one instance of the random.Random() class for
689 each thread, then using .jumpahead() to force each instance to use a
690 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000691
Tim Peters0de88fc2001-02-01 04:59:18 +0000692- random.py's seed() function is new. For bit-for-bit compatibility with
693 prior releases, use the whseed function instead. The new seed function
694 addresses two problems: (1) The old function couldn't produce more than
695 about 2**24 distinct internal states; the new one about 2**45 (the best
696 that can be done in the Wichmann-Hill generator). (2) The old function
697 sometimes produced identical internal states when passed distinct
698 integers, and there was no simple way to predict when that would happen;
699 the new one guarantees to produce distinct internal states for all
700 arguments in [0, 27814431486576L).
701
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000702- The socket module now supports raw packets on Linux. The socket
703 family is AF_PACKET.
704
Tim Peters9ea17ac2001-02-02 05:57:15 +0000705- test_capi.py is a start at running tests of the Python C API. The tests
706 are implemented by the new Modules/_testmodule.c.
707
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000708- A new extension module, _symtable, provides provisional access to the
709 internal symbol table used by the Python compiler. A higher-level
710 interface will be added on top of _symtable in a future release.
711
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000712- Removed the obsolete soundex module.
713
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000714- xml.dom.minidom now uses the standard DOM exceptions. Node supports
715 the isSameNode method; NamedNodeMap the get method.
716
717- xml.sax.expatreader supports the lexical handler property; it
718 generates comment, startCDATA, and endCDATA events.
719
Tim Petersee826f82001-01-31 19:39:44 +0000720Windows changes
721
722- Build procedure: the zlib project is built in a different way that
723 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000724 the zlib binary used. See PCbuild\readme.txt for details. Your old
725 zlib-related directories can be deleted; you'll need to download fresh
726 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000727
Tim Peters9ea17ac2001-02-02 05:57:15 +0000728- Build: New subproject _test for the benefit of test_capi.py (see above).
729
Tim Petersb16c56f2001-02-02 21:24:51 +0000730- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
731 interface to some Python compiler internals).
732
733- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000734 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000735
Tim Petersa3a3a032000-11-30 05:22:44 +0000736What's New in Python 2.1 alpha 1?
737=================================
738
739Core language, builtins, and interpreter
740
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000741- There is a new Unicode companion to the PyObject_Str() API
742 called PyObject_Unicode(). It behaves in the same way as the
743 former, but assures that the returned value is an Unicode object
744 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000745
Guido van Rossumf98eda02001-01-17 15:54:45 +0000746- The comparison operators support "rich comparison overloading" (PEP
747 207). C extension types can provide a rich comparison function in
748 the new tp_richcompare slot in the type object. The cmp() function
749 and the C function PyObject_Compare() first try the new rich
750 comparison operators before trying the old 3-way comparison. There
751 is also a new C API PyObject_RichCompare() (which also falls back on
752 the old 3-way comparison, but does not constrain the outcome of the
753 rich comparison to a Boolean result).
754
755 The rich comparison function takes two objects (at least one of
756 which is guaranteed to have the type that provided the function) and
757 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
758 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
759 object, which may be NotImplemented (in which case the tp_compare
760 slot function is used as a fallback, if defined).
761
762 Classes can overload individual comparison operators by defining one
763 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000764 __ge__. There are no explicit "reflected argument" versions of
765 these; instead, __lt__ and __gt__ are each other's reflection,
766 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
767 reflection (similar at the C level). No other implications are
768 made; in particular, Python does not assume that == is the Boolean
769 inverse of !=, or that < is the Boolean inverse of >=. This makes
770 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000771
772 Classes or types that want to implement (in)equality tests but not
773 the ordering operators (i.e. unordered types) should implement ==
774 and !=, and raise an error for the ordering operators.
775
Guido van Rossuma88479f2001-01-18 14:28:08 +0000776 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000777 Boolean; e.g. a matrix type might want to return a matrix of bits
778 for A < B, giving elementwise comparisons. Such types should ensure
779 that any interpretation of their value in a Boolean context raises
780 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
781 at the C level) to always raise an exception.
782
Guido van Rossuma88479f2001-01-18 14:28:08 +0000783- Complex numbers use rich comparisons to define == and != but raise
784 an exception for <, <=, > and >=. Unfortunately, this also means
785 that cmp() of two complex numbers raises an exception when the two
786 numbers differ. Since it is not mathematically meaningful to compare
787 complex numbers except for equality, I hope that this doesn't break
788 too much code.
789
Tim Peters3389f192001-02-18 08:48:49 +0000790- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000791 not defined by the language, other than that it's arbitrary but
792 consistent (see the Reference Manual). An implementation detail changed
793 in 2.1a1 such that None now compares less than any other object. Code
794 relying on this new behavior (like code that relied on the previous
795 behavior) does so at its own risk.
796
Barry Warsaw573b5412001-01-15 20:43:18 +0000797- Functions and methods now support getting and setting arbitrarily
798 named attributes (PEP 232). Functions have a new __dict__
799 (a.k.a. func_dict) which hold the function attributes. Methods get
800 and set attributes on their underlying im_func. It is a TypeError
801 to set an attribute on a bound method.
802
Guido van Rossum051e3352001-01-15 19:11:10 +0000803- The xrange() object implementation has been improved so that
804 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
805 limitation that in this case len(xrange(sys.maxint)) can't be
806 calculated, but the common idiom "for i in xrange(sys.maxint)" will
807 work fine as long as the index i doesn't actually reach 2**31.
808 (Python uses regular ints for sequence and string indices; fixing
809 that is much more work.)
810
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000811- Two changes to from...import:
812
Guido van Rossumba381232001-02-03 15:06:40 +0000813 1) "from M import X" now works even if (after loading module M)
814 sys.modules['M'] is not a real module; it's basically a getattr()
815 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000816
817 2) "from M import *" now looks for M.__all__ to decide which names to
818 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
819 filters out names starting with '_' as before. Whether or not
820 __all__ exists, there's no restriction on the type of M.
821
Guido van Rossumf61f1662001-01-10 20:13:55 +0000822- File objects have a new method, xreadlines(). This is the fastest
823 way to iterate over all lines in a file:
824
825 for line in file.xreadlines():
826 ...do something to line...
827
828 See the xreadlines module (mentioned below) for how to do this for
829 other file-like objects.
830
831- Even if you don't use file.xreadlines(), you may expect a speedup on
832 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000833 quite a bit in platform-specific ways: on systems (like Linux) that
834 support flockfile(), getc_unlocked(), and funlockfile(), those are
835 used by default. On systems (like Windows) without getc_unlocked(),
836 a complicated (but still thread-safe) method using fgets() is used by
837 default.
838
Tim Petersd52269b2001-01-25 06:23:18 +0000839 You can force use of the fgets() method by #define'ing
840 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000841 getc_unlocked()).
842
Tim Petersd52269b2001-01-25 06:23:18 +0000843 You can force fgets() not to be used by #define'ing
844 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000845 test_bufio.py fails -- and let us know if it does!).
846
847- In addition, the fileinput module, while still slower than the other
848 methods on most platforms, has been sped up too, by using
849 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000850
851- Support for run-time warnings has been added, including a new
852 command line option (-W) to specify the disposition of warnings.
853 See the description of the warnings module below.
854
855- Extensive changes have been made to the coercion code. This mostly
856 affects extension modules (which can now implement mixed-type
857 numerical operators without having to use coercion), but
858 occasionally, in boundary cases the coercion semantics have changed
859 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000860 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000861 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000862 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000863
Guido van Rossumf98eda02001-01-17 15:54:45 +0000864- In connection with the coercion changes, a new built-in singleton
865 object, NotImplemented is defined. This can be returned for
866 operations that wish to indicate they are not implemented for a
867 particular combination of arguments. From C, this is
868 Py_NotImplemented.
869
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000870- The interpreter accepts now bytecode files on the command line even
871 if they do not have a .pyc or .pyo extension. On Linux, after executing
872
Martin v. Löwise214baa2001-02-04 22:37:56 +0000873import imp,sys,string
874magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
875reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
876open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000877
878 any byte code file can be used as an executable (i.e. as an argument
879 to execve(2)).
880
Tim Peters9940b802000-12-01 07:59:35 +0000881- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000882 character. In 1.6 and earlier, they never produced a sign,
883 and raised an error if the value of the long was too large
884 to fit in a Python int. In 2.0, they produced a sign if and
885 only if too large to fit in an int. This was inconsistent
886 across platforms (because the size of an int varies across
887 platforms), and inconsistent with hex() and oct(). Example:
888
889 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000890 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000891 'ffffffbe' # in 2.0 and before, on 32-bit machines
892 >>> hex(-0x42L)
893 '-0x42L' # in all versions of Python
894
Tim Peters9940b802000-12-01 07:59:35 +0000895 The behavior of %d formats for negative Python longs remains
896 the same as in 2.0 (although in 1.6 and before, they raised
897 an error if the long didn't fit in a Python int).
898
899 %u formats don't make sense for Python longs, but are allowed
900 and treated the same as %d in 2.1. In 2.0, a negative long
901 formatted via %u produced a sign if and only if too large to
902 fit in an int. In 1.6 and earlier, a negative long formatted
903 via %u raised an error if it was too big to fit in an int.
904
Guido van Rossum3661d392000-12-12 22:10:31 +0000905- Dictionary objects have an odd new method, popitem(). This removes
906 an arbitrary item from the dictionary and returns it (in the form of
907 a (key, value) pair). This can be useful for algorithms that use a
908 dictionary as a bag of "to do" items and repeatedly need to pick one
909 item. Such algorithms normally end up running in quadratic time;
910 using popitem() they can usually be made to run in linear time.
911
Tim Peters36cdad12000-12-29 02:06:45 +0000912Standard library
913
Thomas Woutersfe385252001-01-19 23:16:56 +0000914- In the time module, the time argument to the functions strftime,
915 localtime, gmtime, asctime and ctime is now optional, defaulting to
916 the current time (in the local timezone).
917
Guido van Rossumda91f222001-01-15 16:36:08 +0000918- The ftplib module now defaults to passive mode, which is deemed a
919 more useful default given that clients are often inside firewalls
920 these days. Note that this could break if ftplib is used to connect
921 to a *server* that is inside a firewall, from outside; this is
922 expected to be a very rare situation. To fix that, you can call
923 ftp.set_pasv(0).
924
Martin v. Löwis10a27872001-01-13 09:54:41 +0000925- The module site now treats .pth files not only for path configuration,
926 but also supports extensions to the initialization code: Lines starting
927 with import are executed.
928
Guido van Rossumf61f1662001-01-10 20:13:55 +0000929- There's a new module, warnings, which implements a mechanism for
930 issuing and filtering warnings. There are some new built-in
931 exceptions that serve as warning categories, and a new command line
932 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
933 turns warnings into errors). warnings.warn(message[, category])
934 issues a warning message; this can also be called from C as
935 PyErr_Warn(category, message).
936
937- A new module xreadlines was added. This exports a single factory
938 function, xreadlines(). The intention is that this code is the
939 absolutely fastest way to iterate over all lines in an open
940 file(-like) object:
941
942 import xreadlines
943 for line in xreadlines.xreadlines(file):
944 ...do something to line...
945
946 This is equivalent to the previous the speed record holder using
947 file.readlines(sizehint). Note that if file is a real file object
948 (as opposed to a file-like object), this is equivalent:
949
950 for line in file.xreadlines():
951 ...do something to line...
952
Tim Peters36cdad12000-12-29 02:06:45 +0000953- The bisect module has new functions bisect_left, insort_left,
954 bisect_right and insort_right. The old names bisect and insort
955 are now aliases for bisect_right and insort_right. XXX_right
956 and XXX_left methods differ in what happens when the new element
957 compares equal to one or more elements already in the list: the
958 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000959 right. Code that doesn't care where equal elements end up should
960 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000961
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000962- The new curses.panel module wraps the panel library that forms part
963 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
964
Guido van Rossumf61f1662001-01-10 20:13:55 +0000965- The SocketServer module now sets the allow_reuse_address flag by
966 default in the TCPServer class.
967
968- A new function, sys._getframe(), returns the stack frame pointer of
969 the caller. This is intended only as a building block for
970 higher-level mechanisms such as string interpolation.
971
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000972- The pyexpat module supports a number of new handlers, which are
973 available only in expat 1.2. If invocation of a callback fails, it
974 will report an additional frame in the traceback. Parser objects
975 participate now in garbage collection. If expat reports an unknown
976 encoding, pyexpat will try to use a Python codec; that works only
977 for single-byte charsets. The parser type objects is exposed as
978 XMLParserObject.
979
980- xml.dom now offers standard definitions for symbolic node type and
981 exception code constants, and a hierarchy of DOM exceptions. minidom
982 was adjusted to use them.
983
984- The conformance of xml.dom.minidom to the DOM specification was
985 improved. It detects a number of additional error cases; the
986 previous/next relationship works even when the tree is modified;
987 Node supports the normalize() method; NamedNodeMap, DocumentType and
988 DOMImplementation classes were added; Element supports the
989 hasAttribute and hasAttributeNS methods; and Text supports the splitText
990 method.
991
Guido van Rossumf61f1662001-01-10 20:13:55 +0000992Build issues
993
Guido van Rossum1e33bdc2001-01-23 03:17:00 +0000994- For Unix (and Unix-compatible) builds, configuration and building of
995 extension modules is now greatly automated. Rather than having to
996 edit the Modules/Setup file to indicate which modules should be
997 built and where their include files and libraries are, a
998 distutils-based setup.py script now takes care of building most
999 extension modules. All extension modules built this way are built
1000 as shared libraries. Only a few modules that must be linked
1001 statically are still listed in the Setup file; you won't need to
1002 edit their configuration.
1003
1004- Python should now build out of the box on Cygwin. If it doesn't,
1005 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001006
1007- Python now always uses its own (renamed) implementation of getopt()
1008 -- there's too much variation among C library getopt()
1009 implementations.
1010
1011- C++ compilers are better supported; the CXX macro is always set to a
1012 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001013
Tim Petersd92dfe02000-12-12 01:18:41 +00001014Windows changes
1015
1016- select module: By default under Windows, a select() call
1017 can specify no more than 64 sockets. Python now boosts
1018 this Microsoft default to 512. If you need even more than
1019 that, see the MS docs (you'll need to #define FD_SETSIZE
1020 and recompile Python from source).
1021
Guido van Rossumf61f1662001-01-10 20:13:55 +00001022- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1023 subdirectory is no more!
1024
Tim Petersa3a3a032000-11-30 05:22:44 +00001025
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001026What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001027=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001028
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001029Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001030changes are in the file HISTORY. If you are making the jump directly
1031from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1032HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001033
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001034Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1035the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1036http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001037
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001038--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001039
1040======================================================================
1041
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001042What's new in 2.0 (since release candidate 1)?
1043==============================================
1044
1045Standard library
1046
1047- The copy_reg module was modified to clarify its intended use: to
1048 register pickle support for extension types, not for classes.
1049 pickle() will raise a TypeError if it is passed a class.
1050
1051- Fixed a bug in gettext's "normalize and expand" code that prevented
1052 it from finding an existing .mo file.
1053
1054- Restored support for HTTP/0.9 servers in httplib.
1055
Tim Peters989b7b92000-10-16 20:24:53 +00001056- The math module was changed to stop raising OverflowError in case of
1057 underflow, and return 0 instead in underflow cases. Whether Python
1058 used to raise OverflowError in case of underflow was platform-
1059 dependent (it did when the platform math library set errno to ERANGE
1060 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001061
1062- Fixed a bug in StringIO that occurred when the file position was not
1063 at the end of the file and write() was called with enough data to
1064 extend past the end of the file.
1065
1066- Fixed a bug that caused Tkinter error messages to get lost on
1067 Windows. The bug was fixed by replacing direct use of
1068 interp->result with Tcl_GetStringResult(interp).
1069
1070- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1071 redirect response.
1072
1073- Several changes were made to distutils: Some debugging code was
1074 removed from util. Fixed the installer used when an external zip
1075 program (like WinZip) is not found; the source code for this
1076 installer is in Misc/distutils. check_lib() was modified to behave
1077 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1078 test for whether installed modules are on sys.path was changed to
1079 use both normcase() and normpath().
1080
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001081- Several minor bugs were fixed in the xml package (the minidom,
1082 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001083
1084- The regression test driver (regrtest.py) behavior when invoked with
1085 -l changed: It now reports a count of objects that are recognized as
1086 garbage but not freed by the garbage collector.
1087
Tim Peters989b7b92000-10-16 20:24:53 +00001088- The regression test for the math module was changed to test
1089 exceptional behavior when the test is run in verbose mode. Python
1090 cannot yet guarantee consistent exception behavior across platforms,
1091 so the exception part of test_math is run only in verbose mode, and
1092 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001093
1094Internals
1095
1096- PyOS_CheckStack() has been disabled on Win64, where it caused
1097 test_sre to fail.
1098
1099Build issues
1100
1101- Changed compiler flags, so that gcc is always invoked with -Wall and
1102 -Wstrict-prototypes. Users compiling Python with GCC should see
1103 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001104 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001105 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001106
Tim Petersa3a3a032000-11-30 05:22:44 +00001107- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001108
1109Tools and other miscellany
1110
1111- The compiler in Tools/compiler was updated to support the new
1112 language features introduced in 2.0: extended print statement, list
1113 comprehensions, and augmented assignments. The new compiler should
1114 also be backwards compatible with Python 1.5.2; the compiler will
1115 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001116 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001117
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001118What's new in 2.0 release candidate 1 (since beta 2)?
1119=====================================================
1120
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001121What is release candidate 1?
1122
1123We believe that release candidate 1 will fix all known bugs that we
1124intend to fix for the 2.0 final release. This release should be a bit
1125more stable than the previous betas. We would like to see even more
1126widespread testing before the final release, so we are producing this
1127release candidate. The final release will be exactly the same unless
1128any show-stopping (or brown bag) bugs are found by testers of the
1129release candidate.
1130
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001131All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001132to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001133
1134Core language, builtins, and interpreter
1135
1136- A bug that caused crashes when __coerce__ was used with augmented
1137 assignment, e.g. +=, was fixed.
1138
1139- Raise ZeroDivisionError when raising zero to a negative number,
1140 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1141 power operator and the result of math.pow(0.0, -2.0) will vary by
1142 platform. On Linux, it raises a ValueError.
1143
1144- A bug in Unicode string interpolation was fixed that occasionally
1145 caused errors with formats including "%%". For example, the
1146 following expression "%% %s" % u"abc" no longer raises a TypeError.
1147
1148- Compilation of deeply nested expressions raises MemoryError instead
1149 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1150
1151- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1152 rendering them useless. They are now written in binary mode again.
1153
1154Standard library
1155
1156- Keyword arguments are now accepted for most pattern and match object
1157 methods in SRE, the standard regular expression engine.
1158
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001159- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001160 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001161
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001162- Several bugs in the Unicode handling and error handling in _tkinter
1163 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001164
1165- Fix memory management errors in Merge() and Tkapp_Call() routines.
1166
1167- Several changes were made to cStringIO to make it compatible with
1168 the file-like object interface and with StringIO. If operations are
1169 performed on a closed object, an exception is raised. The truncate
1170 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001171 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001172
1173- There were many changes made to the linuxaudiodev module and its
1174 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001175 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001176
1177 Note that this module is named poorly, because it should work
1178 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001179 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001180
1181 The module now raises exceptions when errors occur instead of
1182 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1183 audio) and defines a getptr() method that calls the
1184 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1185
1186- The library_version attribute, introduced in an earlier beta, was
1187 removed because it can not be supported with early versions of the C
1188 readline library, which provides no way to determine the version at
1189 compile-time.
1190
1191- The binascii module is now enabled on Win64.
1192
Tim Peters46446d62000-10-09 21:19:31 +00001193- tokenize.py no longer suffers "recursion depth" errors when parsing
1194 programs with very long string literals.
1195
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001196Internals
1197
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001198- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001199 which is called when the interpreter starts up to determine where
1200 the standard library is installed. These vulnerabilities affect all
1201 previous versions of Python and can be exploited by setting very
1202 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1203 setuid Python script, although use of the wrapper in
1204 Misc/setuid-prog.c will eliminate the vulnerability.
1205
1206- Fixed garbage collection bugs in instance creation that were
1207 triggered when errors occurred during initialization. The solution,
1208 applied in cPickle and in PyInstance_New(), is to call
1209 PyObject_GC_Init() after the initialization of the object's
1210 container attributes is complete.
1211
1212- pyexpat adds definitions of PyModule_AddStringConstant and
1213 PyModule_AddObject if the Python version is less than 2.0, which
1214 provides compatibility with PyXML on Python 1.5.2.
1215
1216- If the platform has a bogus definition for LONG_BIT (the number of
1217 bits in a long), an error will be reported at compile time.
1218
1219- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1220 collection crashes and possibly other, unreported crashes.
1221
1222- Fixed a memory leak in _PyUnicode_Fini().
1223
1224Build issues
1225
1226- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001227 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001228 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001229
1230- The mmap.PAGESIZE constant is now initialized using sysconf when
1231 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1232
1233- The md5 file should now compile on all platforms.
1234
1235- The select module now compiles on platforms that do not define
1236 POLLRDNORM and related constants.
1237
1238- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001239 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001240
Jeremy Hylton10921202000-10-09 18:34:12 +00001241- BeOS: A number of changes were made to the build and installation
1242 process. ar-fake now operates on a directory of object files.
1243 dl_export.h is gone, and its macros now appear on the mwcc command
1244 line during build on PPC BeOS.
1245
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001246- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001247 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001248
1249- Cygwin: Support for shared libraries, Tkinter, and sockets.
1250
1251- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1252
1253Tools and other miscellany
1254
1255- Removed debugging prints from main used with freeze.
1256
Tim Peters46446d62000-10-09 21:19:31 +00001257- IDLE auto-indent no longer crashes when it encounters Unicode
1258 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001259
1260What's new in 2.0 beta 2 (since beta 1)?
1261========================================
1262
1263Core language, builtins, and interpreter
1264
Tim Peters482c0212000-09-26 06:33:09 +00001265- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001266 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001267
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001268- Add -h and -V command line options to print the usage message and
1269 Python version number and exit immediately.
1270
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001271- eval() and exec accept Unicode objects as code parameters.
1272
1273- getattr() and setattr() now also accept Unicode objects for the
1274 attribute name, which are converted to strings using the default
1275 encoding before lookup.
1276
1277- Multiplication on string and Unicode now does proper bounds
1278 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1279 string is too long."
1280
1281- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001282 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001283
Jeremy Hylton1b618592000-09-26 05:32:36 +00001284
1285Standard library and extensions
1286
Guido van Rossum5b08f132001-04-16 02:05:23 +00001287- socket module: the OpenSSL code now adds support for RAND_status()
1288 and EGD (Entropy Gathering Device).
1289
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001290- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001291 argument checking; it still takes no arguments.
1292
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001293- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001294
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001295- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001296
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001297- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001298
1299- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001300 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001301
1302- copy: Copy Unicode objects atomically.
1303
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001304- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001305
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001306- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001307
Fred Drake67233bc2000-09-26 16:40:27 +00001308- dbm: Add get() and setdefault() methods to dbm object. Add constant
1309 `library' to module that names the library used. Added doc strings
1310 and method names to error messages. Uses configure to determine
1311 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1312 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001313
1314- distutils: Update to version 0.9.3.
1315
1316- dl: Add several dl.RTLD_ constants.
1317
1318- fpectl: Now supported on FreeBSD.
1319
1320- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1321 found by the collector will be saved in gc.garbage. This is useful
1322 for debugging a program that creates reference cycles.
1323
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001324- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001325 of HTTP class. Do not close socket on zero-length response. Do not
1326 crash when server sends invalid content-length header.
1327
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001328- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001329
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001330- marshal: When reading a short, sign-extend on platforms where shorts
1331 are bigger than 16 bits. When reading a long, repair the unportable
1332 sign extension that was being done for 64-bit machines. (It assumed
1333 that signed right shift sign-extends.)
1334
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001335- operator: Add contains(), invert(), __invert__() as aliases for
1336 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001337
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001338- os: Add support for popen2() and popen3() on all platforms where
1339 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001340
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001341- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001342 clicking on a file in Explorer (or passing the file name to the
1343 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001344
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001345- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001346 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001347
1348- pickle: Now raises ValueError when an invalid pickle that contains
1349 a non-string repr where a string repr was expected. This behavior
1350 matches cPickle.
1351
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001352- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001353
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001354- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001355
1356- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001357 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001358 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001359
1360- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001361 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001362
1363- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001364 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001365 few cycles during startup since the first call to
1366 setdefaultencoding() will initialize the codec registry and the
1367 encodings package.
1368
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001369- socket: Support for size hint in readlines() method of object returned
1370 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001371
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001372- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001373 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001374 is followed by whitespace.
1375
Tim Petersa3a3a032000-11-30 05:22:44 +00001376- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001377
1378- struct: Check ranges for bytes and shorts.
1379
1380- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001381 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001382
1383- Tkinter: Image objects are now guaranteed to have unique ids. Set
1384 event.delta to zero if Tk version doesn't support mousewheel.
1385 Removed some debugging prints.
1386
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001387- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001388
Fred Drake67233bc2000-09-26 16:40:27 +00001389- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001390 which works around a bug in Norton AntiVirus 2000 that leads directly
1391 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001392
1393- xml: New version detection code allows PyXML to override standard
1394 XML package if PyXML version is greater than 0.6.1.
1395
Fred Drake64bb3802000-09-26 16:21:35 +00001396- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1397 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1398 tree only for nodes which are sufficiently interesting to a specific
1399 application. Does not provide the HTML-specific extensions. Still
1400 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001401
Fred Drake64bb3802000-09-26 16:21:35 +00001402- xml.sax: SAX 2 support for Python, including all the handler
1403 interfaces needed to process XML 1.0 compliant XML. Some
1404 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001405
Fred Drake64bb3802000-09-26 16:21:35 +00001406- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1407 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001408
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001409
Jeremy Hylton1b618592000-09-26 05:32:36 +00001410C API
1411
1412- Add three new convenience functions for module initialization --
1413 PyModule_AddObject(), PyModule_AddIntConstant(), and
1414 PyModule_AddStringConstant().
1415
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001416- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001417 removed and add #error to Python.h if NULL isn't defined after
1418 #include of stdio.h.
1419
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001420- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001421 backwards compatibility (at the source level) with old extensions.
1422
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001423- A wrapper API was added for signal() and sigaction(). Instead of
1424 either function, always use PyOS_getsig() to get a signal handler
1425 and PyOS_setsig() to set one. A new convenience typedef
1426 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001427
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001428- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001429 internal data buffer and size of a string object -- or the default
1430 encoded version of a Unicode object.
1431
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001432- PyString_Size() and PyString_AsString() accept Unicode objects.
1433
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001434- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001435 exists). INT_MAX and LONG_MAX will always be defined, even if
1436 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001437
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001438- PyFloat_FromString takes a second argument, pend, that was
1439 effectively useless. It is now officially useless but preserved for
1440 backwards compatibility. If the pend argument is not NULL, *pend is
1441 set to NULL.
1442
1443- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1444 for the attribute name. See note on getattr() above.
1445
1446- A few bug fixes to argument processing for Unicode.
1447 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1448 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1449 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001450 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001451
1452- Py_BuildValue accepts B format (for bgen-generated code).
1453
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001454
Jeremy Hylton1b618592000-09-26 05:32:36 +00001455Internals
1456
1457- On Unix, fix code for finding Python installation directory so that
1458 it works when argv[0] is a relative path.
1459
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001460- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001461 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001462 rather than by generating a copy of the object.
1463
Tim Peters482c0212000-09-26 06:33:09 +00001464- Several of the internal Unicode tables are much smaller now, and
1465 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001466
Jeremy Hylton97693b02000-09-26 17:42:51 +00001467- In the garbage collector: Fixed bug in collection of tuples. Fixed
1468 bug that caused some instances to be removed from the container set
1469 while they were still live. Fixed parsing in gc.set_debug() for
1470 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001471
1472- Fixed refcount problem in instance deallocation that only occurred
1473 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1474
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001475- On Windows, getpythonregpath is now protected against null data in
1476 registry key.
1477
1478- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001479 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001480
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001481
Jeremy Hylton1b618592000-09-26 05:32:36 +00001482Build and platform-specific issues
1483
1484- Better support of GNU Pth via --with-pth configure option.
1485
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001486- Python/C API now properly exposed to dynamically-loaded extension
1487 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001488
1489- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1490 Don't define MS_SYNC to be zero when it is undefined. Added missing
1491 prototypes in posixmodule.c.
1492
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001493- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001494 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001495
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001496- Fix largefile support on older NetBSD systems and OpenBSD by adding
1497 define for TELL64.
1498
1499
1500Tools and other miscellany
1501
1502- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1503
1504- freeze: The modulefinder now works with 2.0 opcodes.
1505
Tim Petersa3a3a032000-11-30 05:22:44 +00001506- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001507 Move hackery of sys.argv until after the Tk instance has been
1508 created, which allows the application-specific Tkinter
1509 initialization to be executed if present; also pass an explicit
1510 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001511
Jeremy Hylton1b618592000-09-26 05:32:36 +00001512
1513What's new in 2.0 beta 1?
1514=========================
1515
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001516Source Incompatibilities
1517------------------------
1518
1519None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1520such as single-argument append(), connect() and bind(), and changes to
1521str(long) and repr(float).
1522
1523
1524Binary Incompatibilities
1525------------------------
1526
1527- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1528with Python 2.0; these extensions will have to be rebuilt for Python
15292.0.
1530
1531- On Windows, attempting to import a third party extension built for
1532Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1533can do about this. Check your PYTHONPATH environment variable!
1534
1535- Python bytecode files (*.pyc and *.pyo) are not compatible between
1536releases.
1537
1538
1539Overview of Changes Since 1.6
1540-----------------------------
1541
1542There are many new modules (including brand new XML support through
1543the xml package, and i18n support through the gettext module); a list
1544of all new modules is included below. Lots of bugs have been fixed.
1545
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001546The process for making major new changes to the language has changed
1547since Python 1.6. Enhancements must now be documented by a Python
1548Enhancement Proposal (PEP) before they can be accepted.
1549
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001550There are several important syntax enhancements, described in more
1551detail below:
1552
1553 - Augmented assignment, e.g. x += 1
1554
1555 - List comprehensions, e.g. [x**2 for x in range(10)]
1556
1557 - Extended import statement, e.g. import Module as Name
1558
1559 - Extended print statement, e.g. print >> file, "Hello"
1560
1561Other important changes:
1562
1563 - Optional collection of cyclical garbage
1564
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001565Python Enhancement Proposal (PEP)
1566---------------------------------
1567
1568PEP stands for Python Enhancement Proposal. A PEP is a design
1569document providing information to the Python community, or describing
1570a new feature for Python. The PEP should provide a concise technical
1571specification of the feature and a rationale for the feature.
1572
1573We intend PEPs to be the primary mechanisms for proposing new
1574features, for collecting community input on an issue, and for
1575documenting the design decisions that have gone into Python. The PEP
1576author is responsible for building consensus within the community and
1577documenting dissenting opinions.
1578
1579The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001580
1581Augmented Assignment
1582--------------------
1583
1584This must have been the most-requested feature of the past years!
1585Eleven new assignment operators were added:
1586
Guido van Rossume905e952000-09-05 12:42:46 +00001587 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001588
1589For example,
1590
1591 A += B
1592
1593is similar to
1594
1595 A = A + B
1596
1597except that A is evaluated only once (relevant when A is something
1598like dict[index].attr).
1599
1600However, if A is a mutable object, A may be modified in place. Thus,
1601if A is a number or a string, A += B has the same effect as A = A+B
1602(except A is only evaluated once); but if a is a list, A += B has the
1603same effect as A.extend(B)!
1604
1605Classes and built-in object types can override the new operators in
1606order to implement the in-place behavior; the not-in-place behavior is
1607used automatically as a fallback when an object doesn't implement the
1608in-place behavior. For classes, the method name is derived from the
1609method name for the corresponding not-in-place operator by inserting
1610an 'i' in front of the name, e.g. __iadd__ implements in-place
1611__add__.
1612
1613Augmented assignment was implemented by Thomas Wouters.
1614
1615
1616List Comprehensions
1617-------------------
1618
1619This is a flexible new notation for lists whose elements are computed
1620from another list (or lists). The simplest form is:
1621
1622 [<expression> for <variable> in <sequence>]
1623
Guido van Rossum56db0952000-09-06 23:34:25 +00001624For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001625This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001626
1627You can also add a condition:
1628
1629 [<expression> for <variable> in <sequence> if <condition>]
1630
1631For example, [w for w in words if w == w.lower()] would yield the list
1632of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001633than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001634
1635You can also have nested for loops and more than one 'if' clause. For
1636example, here's a function that flattens a sequence of sequences::
1637
1638 def flatten(seq):
1639 return [x for subseq in seq for x in subseq]
1640
1641 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1642
1643This prints
1644
1645 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1646
1647List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001648Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001649
1650
1651Extended Import Statement
1652-------------------------
1653
1654Many people have asked for a way to import a module under a different
1655name. This can be accomplished like this:
1656
1657 import foo
1658 bar = foo
1659 del foo
1660
1661but this common idiom gets old quickly. A simple extension of the
1662import statement now allows this to be written as follows:
1663
1664 import foo as bar
1665
1666There's also a variant for 'from ... import':
1667
1668 from foo import bar as spam
1669
1670This also works with packages; e.g. you can write this:
1671
1672 import test.regrtest as regrtest
1673
1674Note that 'as' is not a new keyword -- it is recognized only in this
1675context (this is only possible because the syntax for the import
1676statement doesn't involve expressions).
1677
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001678Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001679
1680
1681Extended Print Statement
1682------------------------
1683
1684Easily the most controversial new feature, this extension to the print
1685statement adds an option to make the output go to a different file
1686than the default sys.stdout.
1687
1688For example, to write an error message to sys.stderr, you can now
1689write:
1690
1691 print >> sys.stderr, "Error: bad dog!"
1692
1693As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001694evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001695
1696 print >> None, "Hello world"
1697
1698is equivalent to
1699
1700 print "Hello world"
1701
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001702Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001703
1704
1705Optional Collection of Cyclical Garbage
1706---------------------------------------
1707
1708Python is now equipped with a garbage collector that can hunt down
1709cyclical references between Python objects. It's no replacement for
1710reference counting; in fact, it depends on the reference counts being
1711correct, and decides that a set of objects belong to a cycle if all
1712their reference counts can be accounted for from their references to
1713each other. This devious scheme was first proposed by Eric Tiedemann,
1714and brought to implementation by Neil Schemenauer.
1715
1716There's a module "gc" that lets you control some parameters of the
1717garbage collection. There's also an option to the configure script
1718that lets you enable or disable the garbage collection. In 2.0b1,
1719it's on by default, so that we (hopefully) can collect decent user
1720experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001721performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001722off by default in the final 2.0 release.
1723
1724
1725Smaller Changes
1726---------------
1727
1728A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1729map(None, seq1, seq2, ...) when the sequences have the same length;
1730i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1731the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001732zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001733
1734sys.version_info is a tuple (major, minor, micro, level, serial).
1735
1736Dictionaries have an odd new method, setdefault(key, default).
1737dict.setdefault(key, default) returns dict[key] if it exists; if not,
1738it sets dict[key] to default and returns that value. Thus:
1739
1740 dict.setdefault(key, []).append(item)
1741
1742does the same work as this common idiom:
1743
1744 if not dict.has_key(key):
1745 dict[key] = []
1746 dict[key].append(item)
1747
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001748There are two new variants of SyntaxError that are raised for
1749indentation-related errors: IndentationError and TabError.
1750
1751Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1752escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001753
1754The limits on the size of expressions and file in Python source code
1755have been raised from 2**16 to 2**32. Previous versions of Python
1756were limited because the maximum argument size the Python VM accepted
1757was 2**16. This limited the size of object constructor expressions,
1758e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1759limit was raised thanks to a patch by Charles Waldman that effectively
1760fixes the problem. It is now much more likely that you will be
1761limited by available memory than by an arbitrary limit in Python.
1762
1763The interpreter's maximum recursion depth can be modified by Python
1764programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1765limit is the maximum number of recursive calls that can be made by
1766Python code. The limit exists to prevent infinite recursion from
1767overflowing the C stack and causing a core dump. The default value is
17681000. The maximum safe value for a particular platform can be found
1769by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001770
1771New Modules and Packages
1772------------------------
1773
1774atexit - for registering functions to be called when Python exits.
1775
1776imputil - Greg Stein's alternative API for writing custom import
1777hooks.
1778
1779pyexpat - an interface to the Expat XML parser, contributed by Paul
1780Prescod.
1781
1782xml - a new package with XML support code organized (so far) in three
1783subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1784would fill a volume. There's a special feature whereby a
1785user-installed package named _xmlplus overrides the standard
1786xmlpackage; this is intended to give the XML SIG a hook to distribute
1787backwards-compatible updates to the standard xml package.
1788
1789webbrowser - a platform-independent API to launch a web browser.
1790
1791
Guido van Rossume905e952000-09-05 12:42:46 +00001792Changed Modules
1793---------------
1794
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001795array -- new methods for array objects: count, extend, index, pop, and
1796remove
1797
1798binascii -- new functions b2a_hex and a2b_hex that convert between
1799binary data and its hex representation
1800
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001801calendar -- Many new functions that support features including control
1802over which day of the week is the first day, returning strings instead
1803of printing them. Also new symbolic constants for days of week,
1804e.g. MONDAY, ..., SUNDAY.
1805
1806cgi -- FieldStorage objects have a getvalue method that works like a
1807dictionary's get method and returns the value attribute of the object.
1808
1809ConfigParser -- The parser object has new methods has_option,
1810remove_section, remove_option, set, and write. They allow the module
1811to be used for writing config files as well as reading them.
1812
1813ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001814optionally support the RFC 959 REST command.
1815
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001816gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001817
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001818httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1819the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001820
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001821locale -- implement getdefaultlocale for Win32 and Macintosh
1822
1823marshal -- no longer dumps core when marshaling deeply nested or
1824recursive data structures
1825
1826os -- new functions isatty, seteuid, setegid, setreuid, setregid
1827
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001828os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1829support under Unix.
1830
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001831os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001832
1833os.path -- fix semantics of os.path.commonprefix
1834
1835smtplib -- support for sending very long messages
1836
1837socket -- new function getfqdn()
1838
1839readline -- new functions to read, write and truncate history files.
1840The readline section of the library reference manual contains an
1841example.
1842
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001843select -- add interface to poll system call
1844
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001845shutil -- new copyfileobj function
1846
1847SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1848HTTP server.
1849
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001850Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001851
1852urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001853e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001854
1855whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001856
1857
1858Obsolete Modules
1859----------------
1860
1861None. However note that 1.6 made a whole slew of modules obsolete:
1862stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1863poly, zmod, strop, util, whatsound.
1864
1865
1866Changed, New, Obsolete Tools
1867----------------------------
1868
Tim Peters8b092332000-09-05 20:15:25 +00001869None.
Guido van Rossume905e952000-09-05 12:42:46 +00001870
1871
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001872C-level Changes
1873---------------
1874
1875Several cleanup jobs were carried out throughout the source code.
1876
1877All C code was converted to ANSI C; we got rid of all uses of the
1878Py_PROTO() macro, which makes the header files a lot more readable.
1879
1880Most of the portability hacks were moved to a new header file,
1881pyport.h; several other new header files were added and some old
1882header files were removed, in an attempt to create a more rational set
1883of header files. (Few of these ever need to be included explicitly;
1884they are all included by Python.h.)
1885
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001886Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001887and Win64, especially for the new Intel Itanium processor. Mick also
1888added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001889
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001890The C APIs to return an object's size have been update to consistently
1891use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1892previous versions, the abstract interfaces used PyXXX_Length and the
1893concrete interfaces used PyXXX_Size. The old names,
1894e.g. PyObject_Length, are still available for backwards compatibility
1895at the API level, but are deprecated.
1896
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001897The PyOS_CheckStack function has been implemented on Windows by
1898Fredrik Lundh. It prevents Python from failing with a stack overflow
1899on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001900
1901The GC changes resulted in creation of two new slots on object,
1902tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001903the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001904
1905The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001906C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001907
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001908PyErr_Format has been updated to automatically calculate the size of
1909the buffer needed to hold the formatted result string. This change
1910prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001911
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001912New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001913
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001914PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1915that are the same as their non-Ex counterparts except they take an
1916extra flag argument that tells them to close the file when done.
1917
1918XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001919
Tim Peters8b092332000-09-05 20:15:25 +00001920
1921Windows Changes
1922---------------
1923
1924New popen2/popen3/peopen4 in os module (see Changed Modules above).
1925
1926os.popen is much more usable on Windows 95 and 98. See Microsoft
1927Knowledge Base article Q150956. The Win9x workaround described there
1928is implemented by the new w9xpopen.exe helper in the root of your
1929Python installation. Note that Python uses this internally; it is not
1930a standalone program.
1931
1932Administrator privileges are no longer required to install Python
1933on Windows NT or Windows 2000. If you have administrator privileges,
1934Python's registry info will be written under HKEY_LOCAL_MACHINE.
1935Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001936under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001937uses of Python, but will prevent some advanced uses from working
1938(for example, running a Python script as an NT service, or possibly
1939from CGI).
1940
1941[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1942installer; instead, it installs the needed Tcl/Tk files directly in the
1943Python directory. If you already have a Tcl/Tk installation, this
1944wastes some disk space (about 4 Megs) but avoids problems with
1945conflicting Tcl/Tk installations, and makes it much easier for Python
1946to ensure that Tcl/Tk can find all its files.
1947
1948[This was new in 1.6] The Windows installer now installs by default in
1949\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1950
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001951
1952Updates to the changes between 1.5.2 and 1.6
1953--------------------------------------------
1954
1955The 1.6 NEWS file can't be changed after the release is done, so here
1956is some late-breaking news:
1957
1958New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1959and changes to getlocale() and setlocale().
1960
1961The new module is now enabled per default.
1962
1963It is not true that the encodings codecs cannot be used for normal
1964strings: the string.encode() (which is also present on 8-bit strings
1965!) allows using them for 8-bit strings too, e.g. to convert files from
1966cp1252 (Windows) to latin-1 or vice-versa.
1967
1968Japanese codecs are available from Tamito KAJIYAMA:
1969http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1970
1971
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001972======================================================================