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Tim Petersf553f892001-05-01 20:45:31 +00001What's New in Python 2.2a0?
2===========================
3
4Core
5
Guido van Rossum10315822001-05-01 20:54:30 +00006- Dictionary objects now support the "in" operator: "x in dict" means
7 the same as dict.has_key(x).
8
9- Iterators were added; this is a generalized way of providing values
10 to a for loop. See PEP 234. There's a new built-in function iter()
11 to return an iterator. There's a new protocol to get the next value
12 from an iterator using the next() method (in Python) or the
13 tp_iternext slot (in C). There's a new protocol to get iterators
14 using the __iter__() method (in Python) or the tp_iter slot (in C).
15 Iterating (i.e. a for loop) over a dictionary generates its keys.
16 Iterating over a file generates its lines.
17
Tim Petersf553f892001-05-01 20:45:31 +000018- The following functions were generalized to work nicely with iterator
19 arguments:
Tim Peters0e57abf2001-05-02 07:39:38 +000020 filter()
21 list()
Tim Peters4e9afdc2001-05-03 23:54:49 +000022 map()
Tim Petersc3074532001-05-03 07:00:32 +000023 max()
24 min()
Tim Peters15d81ef2001-05-04 04:39:21 +000025 reduce()
Tim Peters432b42a2001-05-05 04:24:43 +000026 string.join()
Tim Peters6912d4d2001-05-05 03:56:37 +000027 tuple()
Tim Peters2cfe3682001-05-05 05:36:48 +000028 unicode.join()
Tim Peters3e067572001-05-04 04:43:42 +000029 XXX TODO zip()
Tim Peters6912d4d2001-05-05 03:56:37 +000030 XXX TODO 'x in y'
Tim Petersf553f892001-05-01 20:45:31 +000031
Guido van Rossumffe13be2001-04-16 18:46:45 +000032What's New in Python 2.1 (final)?
33=================================
34
35We only changed a few things since the last release candidate, all in
36Python library code:
37
38- A bug in the locale module was fixed that affected locales which
39 define no grouping for numeric formatting.
40
41- A few bugs in the weakref module's implementations of weak
42 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
43 and the test suite was updated to check for these bugs.
44
45- An old bug in the os.path.walk() function (introduced in Python
46 2.0!) was fixed: a non-existent file would cause an exception
47 instead of being ignored.
48
49- Fixed a few bugs in the new symtable module found by Neil Norwitz's
50 PyChecker.
51
52
Guido van Rossum5b08f132001-04-16 02:05:23 +000053What's New in Python 2.1c2?
54===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +000055
Guido van Rossum5b08f132001-04-16 02:05:23 +000056A flurry of small changes, and one showstopper fixed in the nick of
57time made it necessary to release another release candidate. The list
58here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +000059
Guido van Rossum5b08f132001-04-16 02:05:23 +000060Core
Guido van Rossum4fb60362001-04-13 00:46:14 +000061
Guido van Rossum5b08f132001-04-16 02:05:23 +000062- Tim discovered a nasty bug in the dictionary code, caused by
63 PyDict_Next() calling dict_resize(), and the GC code's use of
64 PyDict_Next() violating an assumption in dict_items(). This was
65 fixed with considerable amounts of band-aid, but the net effect is a
66 saner and more robust implementation.
67
68- Made a bunch of symbols static that were accidentally global.
69
70Build and Ports
71
72- The setup.py script didn't check for a new enough version of zlib
73 (1.1.3 is needed). Now it does.
74
75- Changed "make clean" target to also remove shared libraries.
76
77- Added a more general warning about the SGI Irix optimizer to README.
78
79Library
80
81- Fix a bug in urllib.basejoin("http://host", "../file.html") which
82 omitted the slash between host and file.html.
83
84- The mailbox module's _Mailbox class contained a completely broken
85 and undocumented seek() method. Ripped it out.
86
87- Fixed a bunch of typos in various library modules (urllib2, smtpd,
88 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
89
90- Fixed a few last-minute bugs in unittest.
91
92Extensions
93
94- Reverted the patch to the OpenSSL code in socketmodule.c to support
95 RAND_status() and the EGD, and the subsequent patch that tried to
96 fix it for pre-0.9.5 versions; the problem with the patch is that on
97 some systems it issues a warning whenever socket is imported, and
98 that's unacceptable.
99
100Tests
101
102- Fixed the pickle tests to work with "import test.test_pickle".
103
104- Tweaked test_locale.py to actually run the test Windows.
105
106- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
107 not "wb" (which is not a valid mode at all).
108
109- Fix pstats browser crashes. Import readline if it exists to make
110 the user interface nicer.
111
112- Add "import thread" to the top of test modules that import the
113 threading module (test_asynchat and test_threadedtempfile). This
114 prevents test failures caused by a broken threading module resulting
115 from a previously caught failed import.
116
117- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
118 needed on some platforms (e.g. Solaris 8) when the tests are run
119 twice in succession.
120
121- Skip rather than fail test_sunaudiodev if no audio device is found.
122
123
124What's New in Python 2.1c1?
125===========================
126
127This list was significantly updated when 2.1c2 was released; the 2.1c1
128release didn't mention most changes that were actually part of 2.1c1:
129
130Legal
131
132- Copyright was assigned to the Python Software Foundation (PSF) and a
133 PSF license (very similar to the CNRI license) was added.
134
135- The CNRI copyright notice was updated to include 2001.
136
137Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000138
Guido van Rossumc9932722001-04-12 02:31:27 +0000139- After a public outcry, assignment to __debug__ is no longer illegal;
140 instead, a warning is issued. It will become illegal in 2.2.
141
Guido van Rossum5b08f132001-04-16 02:05:23 +0000142- Fixed a core dump with "%#x" % 0, and changed the semantics so that
143 "%#x" now always prepends "0x", even if the value is zero.
144
145- Fixed some nits in the bytecode compiler.
146
147- Fixed core dumps when calling certain kinds of non-functions.
148
149- Fixed various core dumps caused by reference count bugs.
150
151Build and Ports
152
153- Use INSTALL_SCRIPT to install script files.
154
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000155- New port: SCO Unixware 7, by Billy G. Allie.
156
Guido van Rossum5b08f132001-04-16 02:05:23 +0000157- Updated RISCOS port.
158
159- Updated BeOS port and notes.
160
161- Various other porting problems resolved.
162
163Library
164
165- The TERMIOS and SOCKET modules are now truly obsolete and
166 unnecessary. Their symbols are incorporated in the termios and
167 socket modules.
168
169- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
170 better tests for pickling.
171
172- threading: make Condition.wait() robust against KeyboardInterrupt.
173
174- zipfile: add support to zipfile to support opening an archive
175 represented by an open file rather than a file name. Fix bug where
176 the archive was not properly closed. Fixed a bug in this bugfix
177 where flush() was called for a read-only file.
178
179- imputil: added an uninstall() method to the ImportManager.
180
181- Canvas: fixed bugs in lower() and tkraise() methods.
182
183- SocketServer: API change (added overridable close_request() method)
184 so that the TCP server can explicitly close the request.
185
186- pstats: Eric Raymond added a simple interactive statistics browser,
187 invoked when the module is run as a script.
188
189- locale: fixed a problem in format().
190
191- webbrowser: made it work when the BROWSER environment variable has a
192 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
193 KDE 2. Fixed some other nits.
194
195- unittest: changes to allow using a different exception than
196 AssertionError, and added a few more function aliases. Some other
197 small changes.
198
199- urllib, urllib2: fixed redirect problems and a coupleof other nits.
200
201- asynchat: fixed a critical bug in asynchat that slipped through the
202 2.1b2 release. Fixed another rare bug.
203
204- Fix some unqualified except: clauses (always a bad code example).
205
206XML
207
208- pyexpat: new API get_version_string().
209
210- Fixed some minidom bugs.
211
212Extensions
213
214- Fixed a core dump in _weakref. Removed the weakref.mapping()
215 function (it adds nothing to the API).
216
217- Rationalized the use of header files in the readline module, to make
218 it compile (albeit with some warnings) with the very recent readline
219 4.2, without breaking for earlier versions.
220
221- Hopefully fixed a buffering problem in linuxaudiodev.
222
223- Attempted a fix to make the OpenSSL support in the socket module
224 work again with pre-0.9.5 versions of OpenSSL.
225
226Tests
227
228- Added a test case for asynchat and asyncore.
229
230- Removed coupling between tests where one test failing could break
231 another.
232
233Tools
234
235- Ping added an interactive help browser to pydoc, fixed some nits
236 in the rest of the pydoc code, and added some features to his
237 inspect module.
238
239- An updated python-mode.el version 4.1 which integrates Ken
240 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
241 much nicer in XEmacs and Emacs. When stepping through your program
242 with pdb, in either the shell window or the *Python* window, the
243 source file and line will be tracked by an arrow. Very cool!
244
245- IDLE: syntax warnings in interactive mode are changed into errors.
246
247- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000248 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000249
250- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000251
Barry Warsaw11e89c72001-04-11 20:37:57 +0000252
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000253What's New in Python 2.1 beta 2?
254================================
255
Guido van Rossum053ae352001-03-22 14:17:21 +0000256(Unlisted are many fixed bugs, more documentation, etc.)
257
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000258Core language, builtins, and interpreter
259
Guido van Rossum053ae352001-03-22 14:17:21 +0000260- The nested scopes work (enabled by "from __future__ import
261 nested_scopes") is completed; in particular, the future now extends
262 into code executed through exec, eval() and execfile(), and into the
263 interactive interpreter.
264
265- When calling a base class method (e.g. BaseClass.__init__(self)),
266 this is now allowed even if self is not strictly spoken a class
267 instance (e.g. when using metaclasses or the Don Beaudry hook).
268
269- Slice objects are now comparable but not hashable; this prevents
270 dict[:] from being accepted but meaningless.
271
272- Complex division is now calculated using less braindead algorithms.
273 This doesn't change semantics except it's more likely to give useful
274 results in extreme cases. Complex repr() now uses full precision
275 like float repr().
276
277- sgmllib.py now calls handle_decl() for simple <!...> declarations.
278
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000279- It is illegal to assign to the name __debug__, which is set when the
280 interpreter starts. It is effectively a compile-time constant.
281
282- A warning will be issued if a global statement for a variable
283 follows a use or assignment of that variable.
284
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000285Standard library
286
Guido van Rossum053ae352001-03-22 14:17:21 +0000287- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
288 inspired by JUnit), is now part of the standard library. You now
289 have a choice of two testing frameworks: unittest requires you to
290 write testcases as separate code, doctest gathers them from
291 docstrings. Both approaches have their advantages and
292 disadvantages.
293
294- A new module Tix was added, which wraps the Tix extension library
295 for Tk. With that module, it is not necessary to statically link
296 Tix with _tkinter, since Tix will be loaded with Tcl's "package
297 require" command. See Demo/tix/.
298
299- tzparse.py is now obsolete.
300
301- In gzip.py, the seek() and tell() methods are removed -- they were
302 non-functional anyway, and it's better if callers can test for their
303 existence with hasattr().
304
305Python/C API
306
307- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
308 that's already in the dictionary during a PyDict_Next() iteration.
309 This used to fail occasionally when a dictionary resize operation
310 could be triggered that would rehash all the keys. All other
311 modifications to the dictionary are still off-limits during a
312 PyDict_Next() iteration!
313
314- New extended APIs related to passing compiler variables around.
315
316- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
317 implement isinstance() and issubclass().
318
319- Py_BuildValue() now has a "D" conversion to create a Python complex
320 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000321
Fred Drake4e262a92001-03-22 18:26:47 +0000322- Extensions types which support weak references must now set the
323 field allocated for the weak reference machinery to NULL themselves;
324 this is done to avoid the cost of checking each object for having a
325 weakly referencable type in PyObject_INIT(), since most types are
326 not weakly referencable.
327
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000328- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
329 free variables and cell variables to and from the frame's f_locals.
330
331- Variants of several functions defined in pythonrun.h have been added
332 to support the nested_scopes future statement. The variants all end
333 in Flags and take an extra argument, a PyCompilerFlags *; examples:
334 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
335 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000336 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000337
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000338Distutils
339
340- the sdist command now writes a PKG-INFO file, as described in PEP 241,
341 into the release tree.
342
Tim Peters0e57abf2001-05-02 07:39:38 +0000343- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000344 (an uninstaller, more customization of the installer's display)
345
346- from Jack Jansen: added Mac-specific code to generate a dialog for
347 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000348 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000349 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000350
351- added 'platforms' and 'keywords' to the set of metadata that can be
352 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000353
354- applied patches from Jason Tishler to make the compiler class work with
355 Cygwin.
356
357
Tim Peters2fe289a2001-03-01 22:19:38 +0000358What's New in Python 2.1 beta 1?
359================================
Tim Petersd66595f2001-02-04 03:09:53 +0000360
361Core language, builtins, and interpreter
362
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000363- Following an outcry from the community about the amount of code
364 broken by the nested scopes feature introduced in 2.1a2, we decided
365 to make this feature optional, and to wait until Python 2.2 (or at
366 least 6 months) to make it standard. The option can be enabled on a
367 per-module basis by adding "from __future__ import nested_scopes" at
368 the beginning of a module (before any other statements, but after
369 comments and an optional docstring). See PEP 236 (Back to the
370 __future__) for a description of the __future__ statement. PEP 227
371 (Statically Nested Scopes) has been updated to reflect this change,
372 and to clarify the semantics in a number of endcases.
373
374- The nested scopes code, when enabled, has been hardened, and most
375 bugs and memory leaks in it have been fixed.
376
377- Compile-time warnings are now generated for a number of conditions
378 that will break or change in meaning when nested scopes are enabled:
379
380 - Using "from...import *" or "exec" without in-clause in a function
381 scope that also defines a lambda or nested function with one or
382 more free (non-local) variables. The presence of the import* or
383 bare exec makes it impossible for the compiler to determine the
384 exact set of local variables in the outer scope, which makes it
385 impossible to determine the bindings for free variables in the
386 inner scope. To avoid the warning about import *, change it into
387 an import of explicitly name object, or move the import* statement
388 to the global scope; to avoid the warning about bare exec, use
389 exec...in... (a good idea anyway -- there's a possibility that
390 bare exec will be deprecated in the future).
391
392 - Use of a global variable in a nested scope with the same name as a
393 local variable in a surrounding scope. This will change in
394 meaning with nested scopes: the name in the inner scope will
395 reference the variable in the outer scope rather than the global
396 of the same name. To avoid the warning, either rename the outer
397 variable, or use a global statement in the inner function.
398
Neil Schemenauera35c6882001-02-27 04:45:05 +0000399- An optional object allocator has been included. This allocator is
400 optimized for Python objects and should be faster and use less memory
401 than the standard system allocator. It is not enabled by default
402 because of possible thread safety problems. The allocator is only
403 protected by the Python interpreter lock and it is possible that some
404 extension modules require a thread safe allocator. The object
405 allocator can be enabled by providing the "--with-pymalloc" option to
406 configure.
407
Tim Petersd66595f2001-02-04 03:09:53 +0000408Standard library
409
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000410- pyexpat now detects the expat version if expat.h defines it. A
411 number of additional handlers are provided, which are only available
412 since expat 1.95. In addition, the methods SetParamEntityParsing and
413 GetInputContext of Parser objects are available with 1.95.x
414 only. Parser objects now provide the ordered_attributes and
415 specified_attributes attributes. A new module expat.model was added,
416 which offers a number of additional constants if 1.95.x is used.
417
418- xml.dom offers the new functions registerDOMImplementation and
419 getDOMImplementation.
420
421- xml.dom.minidom offers a toprettyxml method. A number of DOM
422 conformance issues have been resolved. In particular, Element now
423 has an hasAttributes method, and the handling of namespaces was
424 improved.
425
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000426- Ka-Ping Yee contributed two new modules: inspect.py, a module for
427 getting information about live Python code, and pydoc.py, a module
428 for interactively converting docstrings to HTML or text.
429 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000430 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000431 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
432 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000433
Tim Peters1eff7962001-03-01 02:31:33 +0000434- New library module difflib.py, primarily packaging the SequenceMatcher
435 class at the heart of the popular ndiff.py file-comparison tool.
436
437- doctest.py (a framework for verifying Python code examples in docstrings)
438 is now part of the std library.
439
Tim Petersd66595f2001-02-04 03:09:53 +0000440Windows changes
441
Guido van Rossume3955a82001-03-02 14:05:59 +0000442- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
443 small GUI that lets you browse the module docstrings using your
444 default web browser.
445
Tim Peters1eff7962001-03-01 02:31:33 +0000446- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
447 Platforms) is implemented. See
448
449 http://python.sourceforge.net/peps/pep-0235.html
450
451 for full details, especially the "Current Lower-Left Semantics" section.
452 The new Windows import rules are simpler than before:
453
454 A. If the PYTHONCASEOK environment variable exists, same as
455 before: silently accept the first case-insensitive match of any
456 kind; raise ImportError if none found.
457
458 B. Else search sys.path for the first case-sensitive match; raise
459 ImportError if none found.
460
461 The same rules have been implented on other platforms with case-
462 insensitive but case-preserving filesystems too (including Cygwin, and
463 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000464
Tim Peters25a9ce32001-02-19 07:06:36 +0000465- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
466 what it's supposed to do (and does do under NT and 2000) via direct
467 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000468 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000469 all Win9x systems before.
470
Tim Peters1eff7962001-03-01 02:31:33 +0000471- Build: Subproject _test (effectively) renamed to _testcapi.
472
Tim Peters2fe289a2001-03-01 22:19:38 +0000473New platforms
474
475- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
476 Thanks to Steven Majewski!
477
478- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
479 Tishler!
480
Guido van Rossum9089b272001-03-02 06:49:50 +0000481- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
482 Schwertberger! See RISCOS/README for more information -- it seems
483 that because of the bizarre filename conventions on RISCOS, no port
484 to that platform is easy. Note that the new variable os.endsep is
485 silently supported in order to make life easier on this platform,
486 but we don't advertise it because it's not worth for most folks to
487 care about RISCOS portability.
488
Tim Peters25a9ce32001-02-19 07:06:36 +0000489
Tim Petersd7b5e882001-01-25 03:36:26 +0000490What's New in Python 2.1 alpha 2?
491=================================
Tim Peters40ead762001-01-27 05:35:26 +0000492
Tim Petersd7b5e882001-01-25 03:36:26 +0000493Core language, builtins, and interpreter
494
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000495- Scopes nest. If a name is used in a function or class, but is not
496 local, the definition in the nearest enclosing function scope will
497 be used. One consequence of this change is that lambda statements
498 could reference variables in the namespaces where the lambda is
499 defined. In some unusual cases, this change will break code.
500
501 In all previous version of Python, names were resolved in exactly
502 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000503 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000504 function A is defined within a function B, the names bound in B are
505 not visible in A. The new rules make names bound in B visible in A,
506 unless A contains a name binding that hides the binding in B.
507
508 Section 4.1 of the reference manual describes the new scoping rules
509 in detail. The test script in Lib/test/test_scope.py demonstrates
510 some of the effects of the change.
511
512 The new rules will cause existing code to break if it defines nested
513 functions where an outer function has local variables with the same
514 name as globals or builtins used by the inner function. Example:
515
516 def munge(str):
517 def helper(x):
518 return str(x)
519 if type(str) != type(''):
520 str = helper(str)
521 return str.strip()
522
523 Under the old rules, the name str in helper() is bound to the
524 builtin function str(). Under the new rules, it will be bound to
525 the argument named str and an error will occur when helper() is
526 called.
527
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000528- The compiler will report a SyntaxError if "from ... import *" occurs
529 in a function or class scope. The language reference has documented
530 that this case is illegal, but the compiler never checked for it.
531 The recent introduction of nested scope makes the meaning of this
532 form of name binding ambiguous. In a future release, the compiler
533 may allow this form when there is no possibility of ambiguity.
534
Tim Peters40ead762001-01-27 05:35:26 +0000535- repr(string) is easier to read, now using hex escapes instead of octal,
536 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
537
538 >>> "\texample \r\n" + chr(0) + chr(255)
539 '\texample \r\n\x00\xff' # in 2.1
540 '\011example \015\012\000\377' # in 2.0
541
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000542- Functions are now compared and hashed by identity, not by value, since
543 the func_code attribute is writable.
544
Fred Drakefb9d7122001-02-01 20:00:40 +0000545- Weak references (PEP 205) have been added. This involves a few
546 changes in the core, an extension module (_weakref), and a Python
547 module (weakref). The weakref module is the public interface. It
548 includes support for "explicit" weak references, proxy objects, and
549 mappings with weakly held values.
550
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000551- A 'continue' statement can now appear in a try block within the body
552 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000553 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000554
Tim Petersd7b5e882001-01-25 03:36:26 +0000555Standard library
556
Barry Warsaw30dbd142001-01-31 22:14:01 +0000557- mailbox.py now has a new class, PortableUnixMailbox which is
558 identical to UnixMailbox but uses a more portable scheme for
559 determining From_ separators. Also, the constructors for all the
560 classes in this module have a new optional `factory' argument, which
561 is a callable used when new message classes must be instantiated by
562 the next() method.
563
Tim Petersd7b5e882001-01-25 03:36:26 +0000564- random.py is now self-contained, and offers all the functionality of
565 the now-deprecated whrandom.py. See the docs for details. random.py
566 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000567 and restoring the internal state of the generator; and jumpahead(n),
568 for quickly forcing the internal state to be the same as if n calls to
569 random() had been made. The latter is particularly useful for multi-
570 threaded programs, creating one instance of the random.Random() class for
571 each thread, then using .jumpahead() to force each instance to use a
572 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000573
Tim Peters0de88fc2001-02-01 04:59:18 +0000574- random.py's seed() function is new. For bit-for-bit compatibility with
575 prior releases, use the whseed function instead. The new seed function
576 addresses two problems: (1) The old function couldn't produce more than
577 about 2**24 distinct internal states; the new one about 2**45 (the best
578 that can be done in the Wichmann-Hill generator). (2) The old function
579 sometimes produced identical internal states when passed distinct
580 integers, and there was no simple way to predict when that would happen;
581 the new one guarantees to produce distinct internal states for all
582 arguments in [0, 27814431486576L).
583
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000584- The socket module now supports raw packets on Linux. The socket
585 family is AF_PACKET.
586
Tim Peters9ea17ac2001-02-02 05:57:15 +0000587- test_capi.py is a start at running tests of the Python C API. The tests
588 are implemented by the new Modules/_testmodule.c.
589
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000590- A new extension module, _symtable, provides provisional access to the
591 internal symbol table used by the Python compiler. A higher-level
592 interface will be added on top of _symtable in a future release.
593
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000594- Removed the obsolete soundex module.
595
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000596- xml.dom.minidom now uses the standard DOM exceptions. Node supports
597 the isSameNode method; NamedNodeMap the get method.
598
599- xml.sax.expatreader supports the lexical handler property; it
600 generates comment, startCDATA, and endCDATA events.
601
Tim Petersee826f82001-01-31 19:39:44 +0000602Windows changes
603
604- Build procedure: the zlib project is built in a different way that
605 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000606 the zlib binary used. See PCbuild\readme.txt for details. Your old
607 zlib-related directories can be deleted; you'll need to download fresh
608 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000609
Tim Peters9ea17ac2001-02-02 05:57:15 +0000610- Build: New subproject _test for the benefit of test_capi.py (see above).
611
Tim Petersb16c56f2001-02-02 21:24:51 +0000612- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
613 interface to some Python compiler internals).
614
615- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000616 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000617
Tim Petersa3a3a032000-11-30 05:22:44 +0000618What's New in Python 2.1 alpha 1?
619=================================
620
621Core language, builtins, and interpreter
622
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000623- There is a new Unicode companion to the PyObject_Str() API
624 called PyObject_Unicode(). It behaves in the same way as the
625 former, but assures that the returned value is an Unicode object
626 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000627
Guido van Rossumf98eda02001-01-17 15:54:45 +0000628- The comparison operators support "rich comparison overloading" (PEP
629 207). C extension types can provide a rich comparison function in
630 the new tp_richcompare slot in the type object. The cmp() function
631 and the C function PyObject_Compare() first try the new rich
632 comparison operators before trying the old 3-way comparison. There
633 is also a new C API PyObject_RichCompare() (which also falls back on
634 the old 3-way comparison, but does not constrain the outcome of the
635 rich comparison to a Boolean result).
636
637 The rich comparison function takes two objects (at least one of
638 which is guaranteed to have the type that provided the function) and
639 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
640 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
641 object, which may be NotImplemented (in which case the tp_compare
642 slot function is used as a fallback, if defined).
643
644 Classes can overload individual comparison operators by defining one
645 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000646 __ge__. There are no explicit "reflected argument" versions of
647 these; instead, __lt__ and __gt__ are each other's reflection,
648 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
649 reflection (similar at the C level). No other implications are
650 made; in particular, Python does not assume that == is the Boolean
651 inverse of !=, or that < is the Boolean inverse of >=. This makes
652 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000653
654 Classes or types that want to implement (in)equality tests but not
655 the ordering operators (i.e. unordered types) should implement ==
656 and !=, and raise an error for the ordering operators.
657
Guido van Rossuma88479f2001-01-18 14:28:08 +0000658 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000659 Boolean; e.g. a matrix type might want to return a matrix of bits
660 for A < B, giving elementwise comparisons. Such types should ensure
661 that any interpretation of their value in a Boolean context raises
662 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
663 at the C level) to always raise an exception.
664
Guido van Rossuma88479f2001-01-18 14:28:08 +0000665- Complex numbers use rich comparisons to define == and != but raise
666 an exception for <, <=, > and >=. Unfortunately, this also means
667 that cmp() of two complex numbers raises an exception when the two
668 numbers differ. Since it is not mathematically meaningful to compare
669 complex numbers except for equality, I hope that this doesn't break
670 too much code.
671
Tim Peters3389f192001-02-18 08:48:49 +0000672- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000673 not defined by the language, other than that it's arbitrary but
674 consistent (see the Reference Manual). An implementation detail changed
675 in 2.1a1 such that None now compares less than any other object. Code
676 relying on this new behavior (like code that relied on the previous
677 behavior) does so at its own risk.
678
Barry Warsaw573b5412001-01-15 20:43:18 +0000679- Functions and methods now support getting and setting arbitrarily
680 named attributes (PEP 232). Functions have a new __dict__
681 (a.k.a. func_dict) which hold the function attributes. Methods get
682 and set attributes on their underlying im_func. It is a TypeError
683 to set an attribute on a bound method.
684
Guido van Rossum051e3352001-01-15 19:11:10 +0000685- The xrange() object implementation has been improved so that
686 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
687 limitation that in this case len(xrange(sys.maxint)) can't be
688 calculated, but the common idiom "for i in xrange(sys.maxint)" will
689 work fine as long as the index i doesn't actually reach 2**31.
690 (Python uses regular ints for sequence and string indices; fixing
691 that is much more work.)
692
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000693- Two changes to from...import:
694
Guido van Rossumba381232001-02-03 15:06:40 +0000695 1) "from M import X" now works even if (after loading module M)
696 sys.modules['M'] is not a real module; it's basically a getattr()
697 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000698
699 2) "from M import *" now looks for M.__all__ to decide which names to
700 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
701 filters out names starting with '_' as before. Whether or not
702 __all__ exists, there's no restriction on the type of M.
703
Guido van Rossumf61f1662001-01-10 20:13:55 +0000704- File objects have a new method, xreadlines(). This is the fastest
705 way to iterate over all lines in a file:
706
707 for line in file.xreadlines():
708 ...do something to line...
709
710 See the xreadlines module (mentioned below) for how to do this for
711 other file-like objects.
712
713- Even if you don't use file.xreadlines(), you may expect a speedup on
714 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000715 quite a bit in platform-specific ways: on systems (like Linux) that
716 support flockfile(), getc_unlocked(), and funlockfile(), those are
717 used by default. On systems (like Windows) without getc_unlocked(),
718 a complicated (but still thread-safe) method using fgets() is used by
719 default.
720
Tim Petersd52269b2001-01-25 06:23:18 +0000721 You can force use of the fgets() method by #define'ing
722 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000723 getc_unlocked()).
724
Tim Petersd52269b2001-01-25 06:23:18 +0000725 You can force fgets() not to be used by #define'ing
726 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000727 test_bufio.py fails -- and let us know if it does!).
728
729- In addition, the fileinput module, while still slower than the other
730 methods on most platforms, has been sped up too, by using
731 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000732
733- Support for run-time warnings has been added, including a new
734 command line option (-W) to specify the disposition of warnings.
735 See the description of the warnings module below.
736
737- Extensive changes have been made to the coercion code. This mostly
738 affects extension modules (which can now implement mixed-type
739 numerical operators without having to use coercion), but
740 occasionally, in boundary cases the coercion semantics have changed
741 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000742 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000743 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000744 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000745
Guido van Rossumf98eda02001-01-17 15:54:45 +0000746- In connection with the coercion changes, a new built-in singleton
747 object, NotImplemented is defined. This can be returned for
748 operations that wish to indicate they are not implemented for a
749 particular combination of arguments. From C, this is
750 Py_NotImplemented.
751
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000752- The interpreter accepts now bytecode files on the command line even
753 if they do not have a .pyc or .pyo extension. On Linux, after executing
754
Martin v. Löwise214baa2001-02-04 22:37:56 +0000755import imp,sys,string
756magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
757reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
758open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000759
760 any byte code file can be used as an executable (i.e. as an argument
761 to execve(2)).
762
Tim Peters9940b802000-12-01 07:59:35 +0000763- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000764 character. In 1.6 and earlier, they never produced a sign,
765 and raised an error if the value of the long was too large
766 to fit in a Python int. In 2.0, they produced a sign if and
767 only if too large to fit in an int. This was inconsistent
768 across platforms (because the size of an int varies across
769 platforms), and inconsistent with hex() and oct(). Example:
770
771 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000772 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000773 'ffffffbe' # in 2.0 and before, on 32-bit machines
774 >>> hex(-0x42L)
775 '-0x42L' # in all versions of Python
776
Tim Peters9940b802000-12-01 07:59:35 +0000777 The behavior of %d formats for negative Python longs remains
778 the same as in 2.0 (although in 1.6 and before, they raised
779 an error if the long didn't fit in a Python int).
780
781 %u formats don't make sense for Python longs, but are allowed
782 and treated the same as %d in 2.1. In 2.0, a negative long
783 formatted via %u produced a sign if and only if too large to
784 fit in an int. In 1.6 and earlier, a negative long formatted
785 via %u raised an error if it was too big to fit in an int.
786
Guido van Rossum3661d392000-12-12 22:10:31 +0000787- Dictionary objects have an odd new method, popitem(). This removes
788 an arbitrary item from the dictionary and returns it (in the form of
789 a (key, value) pair). This can be useful for algorithms that use a
790 dictionary as a bag of "to do" items and repeatedly need to pick one
791 item. Such algorithms normally end up running in quadratic time;
792 using popitem() they can usually be made to run in linear time.
793
Tim Peters36cdad12000-12-29 02:06:45 +0000794Standard library
795
Thomas Woutersfe385252001-01-19 23:16:56 +0000796- In the time module, the time argument to the functions strftime,
797 localtime, gmtime, asctime and ctime is now optional, defaulting to
798 the current time (in the local timezone).
799
Guido van Rossumda91f222001-01-15 16:36:08 +0000800- The ftplib module now defaults to passive mode, which is deemed a
801 more useful default given that clients are often inside firewalls
802 these days. Note that this could break if ftplib is used to connect
803 to a *server* that is inside a firewall, from outside; this is
804 expected to be a very rare situation. To fix that, you can call
805 ftp.set_pasv(0).
806
Martin v. Löwis10a27872001-01-13 09:54:41 +0000807- The module site now treats .pth files not only for path configuration,
808 but also supports extensions to the initialization code: Lines starting
809 with import are executed.
810
Guido van Rossumf61f1662001-01-10 20:13:55 +0000811- There's a new module, warnings, which implements a mechanism for
812 issuing and filtering warnings. There are some new built-in
813 exceptions that serve as warning categories, and a new command line
814 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
815 turns warnings into errors). warnings.warn(message[, category])
816 issues a warning message; this can also be called from C as
817 PyErr_Warn(category, message).
818
819- A new module xreadlines was added. This exports a single factory
820 function, xreadlines(). The intention is that this code is the
821 absolutely fastest way to iterate over all lines in an open
822 file(-like) object:
823
824 import xreadlines
825 for line in xreadlines.xreadlines(file):
826 ...do something to line...
827
828 This is equivalent to the previous the speed record holder using
829 file.readlines(sizehint). Note that if file is a real file object
830 (as opposed to a file-like object), this is equivalent:
831
832 for line in file.xreadlines():
833 ...do something to line...
834
Tim Peters36cdad12000-12-29 02:06:45 +0000835- The bisect module has new functions bisect_left, insort_left,
836 bisect_right and insort_right. The old names bisect and insort
837 are now aliases for bisect_right and insort_right. XXX_right
838 and XXX_left methods differ in what happens when the new element
839 compares equal to one or more elements already in the list: the
840 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000841 right. Code that doesn't care where equal elements end up should
842 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000843
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000844- The new curses.panel module wraps the panel library that forms part
845 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
846
Guido van Rossumf61f1662001-01-10 20:13:55 +0000847- The SocketServer module now sets the allow_reuse_address flag by
848 default in the TCPServer class.
849
850- A new function, sys._getframe(), returns the stack frame pointer of
851 the caller. This is intended only as a building block for
852 higher-level mechanisms such as string interpolation.
853
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000854- The pyexpat module supports a number of new handlers, which are
855 available only in expat 1.2. If invocation of a callback fails, it
856 will report an additional frame in the traceback. Parser objects
857 participate now in garbage collection. If expat reports an unknown
858 encoding, pyexpat will try to use a Python codec; that works only
859 for single-byte charsets. The parser type objects is exposed as
860 XMLParserObject.
861
862- xml.dom now offers standard definitions for symbolic node type and
863 exception code constants, and a hierarchy of DOM exceptions. minidom
864 was adjusted to use them.
865
866- The conformance of xml.dom.minidom to the DOM specification was
867 improved. It detects a number of additional error cases; the
868 previous/next relationship works even when the tree is modified;
869 Node supports the normalize() method; NamedNodeMap, DocumentType and
870 DOMImplementation classes were added; Element supports the
871 hasAttribute and hasAttributeNS methods; and Text supports the splitText
872 method.
873
Guido van Rossumf61f1662001-01-10 20:13:55 +0000874Build issues
875
Guido van Rossum1e33bdc2001-01-23 03:17:00 +0000876- For Unix (and Unix-compatible) builds, configuration and building of
877 extension modules is now greatly automated. Rather than having to
878 edit the Modules/Setup file to indicate which modules should be
879 built and where their include files and libraries are, a
880 distutils-based setup.py script now takes care of building most
881 extension modules. All extension modules built this way are built
882 as shared libraries. Only a few modules that must be linked
883 statically are still listed in the Setup file; you won't need to
884 edit their configuration.
885
886- Python should now build out of the box on Cygwin. If it doesn't,
887 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000888
889- Python now always uses its own (renamed) implementation of getopt()
890 -- there's too much variation among C library getopt()
891 implementations.
892
893- C++ compilers are better supported; the CXX macro is always set to a
894 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +0000895
Tim Petersd92dfe02000-12-12 01:18:41 +0000896Windows changes
897
898- select module: By default under Windows, a select() call
899 can specify no more than 64 sockets. Python now boosts
900 this Microsoft default to 512. If you need even more than
901 that, see the MS docs (you'll need to #define FD_SETSIZE
902 and recompile Python from source).
903
Guido van Rossumf61f1662001-01-10 20:13:55 +0000904- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
905 subdirectory is no more!
906
Tim Petersa3a3a032000-11-30 05:22:44 +0000907
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000908What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +0000909=========================
Guido van Rossum61000331997-08-15 04:39:58 +0000910
Guido van Rossum8ed602b2000-09-01 22:34:33 +0000911Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000912changes are in the file HISTORY. If you are making the jump directly
913from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
914HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +0000915
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000916Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
917the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
918http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +0000919
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000920--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +0000921
922======================================================================
923
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000924What's new in 2.0 (since release candidate 1)?
925==============================================
926
927Standard library
928
929- The copy_reg module was modified to clarify its intended use: to
930 register pickle support for extension types, not for classes.
931 pickle() will raise a TypeError if it is passed a class.
932
933- Fixed a bug in gettext's "normalize and expand" code that prevented
934 it from finding an existing .mo file.
935
936- Restored support for HTTP/0.9 servers in httplib.
937
Tim Peters989b7b92000-10-16 20:24:53 +0000938- The math module was changed to stop raising OverflowError in case of
939 underflow, and return 0 instead in underflow cases. Whether Python
940 used to raise OverflowError in case of underflow was platform-
941 dependent (it did when the platform math library set errno to ERANGE
942 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000943
944- Fixed a bug in StringIO that occurred when the file position was not
945 at the end of the file and write() was called with enough data to
946 extend past the end of the file.
947
948- Fixed a bug that caused Tkinter error messages to get lost on
949 Windows. The bug was fixed by replacing direct use of
950 interp->result with Tcl_GetStringResult(interp).
951
952- Fixed bug in urllib2 that caused it to fail when it received an HTTP
953 redirect response.
954
955- Several changes were made to distutils: Some debugging code was
956 removed from util. Fixed the installer used when an external zip
957 program (like WinZip) is not found; the source code for this
958 installer is in Misc/distutils. check_lib() was modified to behave
959 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
960 test for whether installed modules are on sys.path was changed to
961 use both normcase() and normpath().
962
Jeremy Hyltond867a2c2000-10-16 20:41:38 +0000963- Several minor bugs were fixed in the xml package (the minidom,
964 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000965
966- The regression test driver (regrtest.py) behavior when invoked with
967 -l changed: It now reports a count of objects that are recognized as
968 garbage but not freed by the garbage collector.
969
Tim Peters989b7b92000-10-16 20:24:53 +0000970- The regression test for the math module was changed to test
971 exceptional behavior when the test is run in verbose mode. Python
972 cannot yet guarantee consistent exception behavior across platforms,
973 so the exception part of test_math is run only in verbose mode, and
974 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000975
976Internals
977
978- PyOS_CheckStack() has been disabled on Win64, where it caused
979 test_sre to fail.
980
981Build issues
982
983- Changed compiler flags, so that gcc is always invoked with -Wall and
984 -Wstrict-prototypes. Users compiling Python with GCC should see
985 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +0000986 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +0000987 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000988
Tim Petersa3a3a032000-11-30 05:22:44 +0000989- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000990
991Tools and other miscellany
992
993- The compiler in Tools/compiler was updated to support the new
994 language features introduced in 2.0: extended print statement, list
995 comprehensions, and augmented assignments. The new compiler should
996 also be backwards compatible with Python 1.5.2; the compiler will
997 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +0000998 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000999
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001000What's new in 2.0 release candidate 1 (since beta 2)?
1001=====================================================
1002
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001003What is release candidate 1?
1004
1005We believe that release candidate 1 will fix all known bugs that we
1006intend to fix for the 2.0 final release. This release should be a bit
1007more stable than the previous betas. We would like to see even more
1008widespread testing before the final release, so we are producing this
1009release candidate. The final release will be exactly the same unless
1010any show-stopping (or brown bag) bugs are found by testers of the
1011release candidate.
1012
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001013All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001014to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001015
1016Core language, builtins, and interpreter
1017
1018- A bug that caused crashes when __coerce__ was used with augmented
1019 assignment, e.g. +=, was fixed.
1020
1021- Raise ZeroDivisionError when raising zero to a negative number,
1022 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1023 power operator and the result of math.pow(0.0, -2.0) will vary by
1024 platform. On Linux, it raises a ValueError.
1025
1026- A bug in Unicode string interpolation was fixed that occasionally
1027 caused errors with formats including "%%". For example, the
1028 following expression "%% %s" % u"abc" no longer raises a TypeError.
1029
1030- Compilation of deeply nested expressions raises MemoryError instead
1031 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1032
1033- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1034 rendering them useless. They are now written in binary mode again.
1035
1036Standard library
1037
1038- Keyword arguments are now accepted for most pattern and match object
1039 methods in SRE, the standard regular expression engine.
1040
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001041- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001042 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001043
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001044- Several bugs in the Unicode handling and error handling in _tkinter
1045 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001046
1047- Fix memory management errors in Merge() and Tkapp_Call() routines.
1048
1049- Several changes were made to cStringIO to make it compatible with
1050 the file-like object interface and with StringIO. If operations are
1051 performed on a closed object, an exception is raised. The truncate
1052 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001053 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001054
1055- There were many changes made to the linuxaudiodev module and its
1056 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001057 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001058
1059 Note that this module is named poorly, because it should work
1060 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001061 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001062
1063 The module now raises exceptions when errors occur instead of
1064 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1065 audio) and defines a getptr() method that calls the
1066 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1067
1068- The library_version attribute, introduced in an earlier beta, was
1069 removed because it can not be supported with early versions of the C
1070 readline library, which provides no way to determine the version at
1071 compile-time.
1072
1073- The binascii module is now enabled on Win64.
1074
Tim Peters46446d62000-10-09 21:19:31 +00001075- tokenize.py no longer suffers "recursion depth" errors when parsing
1076 programs with very long string literals.
1077
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001078Internals
1079
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001080- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001081 which is called when the interpreter starts up to determine where
1082 the standard library is installed. These vulnerabilities affect all
1083 previous versions of Python and can be exploited by setting very
1084 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1085 setuid Python script, although use of the wrapper in
1086 Misc/setuid-prog.c will eliminate the vulnerability.
1087
1088- Fixed garbage collection bugs in instance creation that were
1089 triggered when errors occurred during initialization. The solution,
1090 applied in cPickle and in PyInstance_New(), is to call
1091 PyObject_GC_Init() after the initialization of the object's
1092 container attributes is complete.
1093
1094- pyexpat adds definitions of PyModule_AddStringConstant and
1095 PyModule_AddObject if the Python version is less than 2.0, which
1096 provides compatibility with PyXML on Python 1.5.2.
1097
1098- If the platform has a bogus definition for LONG_BIT (the number of
1099 bits in a long), an error will be reported at compile time.
1100
1101- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1102 collection crashes and possibly other, unreported crashes.
1103
1104- Fixed a memory leak in _PyUnicode_Fini().
1105
1106Build issues
1107
1108- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001109 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001110 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001111
1112- The mmap.PAGESIZE constant is now initialized using sysconf when
1113 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1114
1115- The md5 file should now compile on all platforms.
1116
1117- The select module now compiles on platforms that do not define
1118 POLLRDNORM and related constants.
1119
1120- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001121 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001122
Jeremy Hylton10921202000-10-09 18:34:12 +00001123- BeOS: A number of changes were made to the build and installation
1124 process. ar-fake now operates on a directory of object files.
1125 dl_export.h is gone, and its macros now appear on the mwcc command
1126 line during build on PPC BeOS.
1127
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001128- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001129 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001130
1131- Cygwin: Support for shared libraries, Tkinter, and sockets.
1132
1133- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1134
1135Tools and other miscellany
1136
1137- Removed debugging prints from main used with freeze.
1138
Tim Peters46446d62000-10-09 21:19:31 +00001139- IDLE auto-indent no longer crashes when it encounters Unicode
1140 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001141
1142What's new in 2.0 beta 2 (since beta 1)?
1143========================================
1144
1145Core language, builtins, and interpreter
1146
Tim Peters482c0212000-09-26 06:33:09 +00001147- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001148 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001149
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001150- Add -h and -V command line options to print the usage message and
1151 Python version number and exit immediately.
1152
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001153- eval() and exec accept Unicode objects as code parameters.
1154
1155- getattr() and setattr() now also accept Unicode objects for the
1156 attribute name, which are converted to strings using the default
1157 encoding before lookup.
1158
1159- Multiplication on string and Unicode now does proper bounds
1160 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1161 string is too long."
1162
1163- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001164 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001165
Jeremy Hylton1b618592000-09-26 05:32:36 +00001166
1167Standard library and extensions
1168
Guido van Rossum5b08f132001-04-16 02:05:23 +00001169- socket module: the OpenSSL code now adds support for RAND_status()
1170 and EGD (Entropy Gathering Device).
1171
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001172- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001173 argument checking; it still takes no arguments.
1174
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001175- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001176
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001177- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001178
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001179- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001180
1181- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001182 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001183
1184- copy: Copy Unicode objects atomically.
1185
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001186- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001187
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001188- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001189
Fred Drake67233bc2000-09-26 16:40:27 +00001190- dbm: Add get() and setdefault() methods to dbm object. Add constant
1191 `library' to module that names the library used. Added doc strings
1192 and method names to error messages. Uses configure to determine
1193 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1194 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001195
1196- distutils: Update to version 0.9.3.
1197
1198- dl: Add several dl.RTLD_ constants.
1199
1200- fpectl: Now supported on FreeBSD.
1201
1202- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1203 found by the collector will be saved in gc.garbage. This is useful
1204 for debugging a program that creates reference cycles.
1205
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001206- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001207 of HTTP class. Do not close socket on zero-length response. Do not
1208 crash when server sends invalid content-length header.
1209
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001210- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001211
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001212- marshal: When reading a short, sign-extend on platforms where shorts
1213 are bigger than 16 bits. When reading a long, repair the unportable
1214 sign extension that was being done for 64-bit machines. (It assumed
1215 that signed right shift sign-extends.)
1216
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001217- operator: Add contains(), invert(), __invert__() as aliases for
1218 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001219
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001220- os: Add support for popen2() and popen3() on all platforms where
1221 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001222
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001223- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001224 clicking on a file in Explorer (or passing the file name to the
1225 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001226
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001227- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001228 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001229
1230- pickle: Now raises ValueError when an invalid pickle that contains
1231 a non-string repr where a string repr was expected. This behavior
1232 matches cPickle.
1233
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001234- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001235
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001236- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001237
1238- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001239 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001240 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001241
1242- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001243 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001244
1245- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001246 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001247 few cycles during startup since the first call to
1248 setdefaultencoding() will initialize the codec registry and the
1249 encodings package.
1250
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001251- socket: Support for size hint in readlines() method of object returned
1252 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001253
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001254- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001255 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001256 is followed by whitespace.
1257
Tim Petersa3a3a032000-11-30 05:22:44 +00001258- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001259
1260- struct: Check ranges for bytes and shorts.
1261
1262- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001263 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001264
1265- Tkinter: Image objects are now guaranteed to have unique ids. Set
1266 event.delta to zero if Tk version doesn't support mousewheel.
1267 Removed some debugging prints.
1268
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001269- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001270
Fred Drake67233bc2000-09-26 16:40:27 +00001271- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001272 which works around a bug in Norton AntiVirus 2000 that leads directly
1273 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001274
1275- xml: New version detection code allows PyXML to override standard
1276 XML package if PyXML version is greater than 0.6.1.
1277
Fred Drake64bb3802000-09-26 16:21:35 +00001278- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1279 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1280 tree only for nodes which are sufficiently interesting to a specific
1281 application. Does not provide the HTML-specific extensions. Still
1282 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001283
Fred Drake64bb3802000-09-26 16:21:35 +00001284- xml.sax: SAX 2 support for Python, including all the handler
1285 interfaces needed to process XML 1.0 compliant XML. Some
1286 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001287
Fred Drake64bb3802000-09-26 16:21:35 +00001288- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1289 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001290
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001291
Jeremy Hylton1b618592000-09-26 05:32:36 +00001292C API
1293
1294- Add three new convenience functions for module initialization --
1295 PyModule_AddObject(), PyModule_AddIntConstant(), and
1296 PyModule_AddStringConstant().
1297
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001298- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001299 removed and add #error to Python.h if NULL isn't defined after
1300 #include of stdio.h.
1301
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001302- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001303 backwards compatibility (at the source level) with old extensions.
1304
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001305- A wrapper API was added for signal() and sigaction(). Instead of
1306 either function, always use PyOS_getsig() to get a signal handler
1307 and PyOS_setsig() to set one. A new convenience typedef
1308 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001309
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001310- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001311 internal data buffer and size of a string object -- or the default
1312 encoded version of a Unicode object.
1313
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001314- PyString_Size() and PyString_AsString() accept Unicode objects.
1315
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001316- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001317 exists). INT_MAX and LONG_MAX will always be defined, even if
1318 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001319
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001320- PyFloat_FromString takes a second argument, pend, that was
1321 effectively useless. It is now officially useless but preserved for
1322 backwards compatibility. If the pend argument is not NULL, *pend is
1323 set to NULL.
1324
1325- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1326 for the attribute name. See note on getattr() above.
1327
1328- A few bug fixes to argument processing for Unicode.
1329 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1330 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1331 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001332 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001333
1334- Py_BuildValue accepts B format (for bgen-generated code).
1335
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001336
Jeremy Hylton1b618592000-09-26 05:32:36 +00001337Internals
1338
1339- On Unix, fix code for finding Python installation directory so that
1340 it works when argv[0] is a relative path.
1341
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001342- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001343 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001344 rather than by generating a copy of the object.
1345
Tim Peters482c0212000-09-26 06:33:09 +00001346- Several of the internal Unicode tables are much smaller now, and
1347 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001348
Jeremy Hylton97693b02000-09-26 17:42:51 +00001349- In the garbage collector: Fixed bug in collection of tuples. Fixed
1350 bug that caused some instances to be removed from the container set
1351 while they were still live. Fixed parsing in gc.set_debug() for
1352 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001353
1354- Fixed refcount problem in instance deallocation that only occurred
1355 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1356
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001357- On Windows, getpythonregpath is now protected against null data in
1358 registry key.
1359
1360- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001361 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001362
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001363
Jeremy Hylton1b618592000-09-26 05:32:36 +00001364Build and platform-specific issues
1365
1366- Better support of GNU Pth via --with-pth configure option.
1367
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001368- Python/C API now properly exposed to dynamically-loaded extension
1369 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001370
1371- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1372 Don't define MS_SYNC to be zero when it is undefined. Added missing
1373 prototypes in posixmodule.c.
1374
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001375- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001376 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001377
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001378- Fix largefile support on older NetBSD systems and OpenBSD by adding
1379 define for TELL64.
1380
1381
1382Tools and other miscellany
1383
1384- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1385
1386- freeze: The modulefinder now works with 2.0 opcodes.
1387
Tim Petersa3a3a032000-11-30 05:22:44 +00001388- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001389 Move hackery of sys.argv until after the Tk instance has been
1390 created, which allows the application-specific Tkinter
1391 initialization to be executed if present; also pass an explicit
1392 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001393
Jeremy Hylton1b618592000-09-26 05:32:36 +00001394
1395What's new in 2.0 beta 1?
1396=========================
1397
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001398Source Incompatibilities
1399------------------------
1400
1401None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1402such as single-argument append(), connect() and bind(), and changes to
1403str(long) and repr(float).
1404
1405
1406Binary Incompatibilities
1407------------------------
1408
1409- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1410with Python 2.0; these extensions will have to be rebuilt for Python
14112.0.
1412
1413- On Windows, attempting to import a third party extension built for
1414Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1415can do about this. Check your PYTHONPATH environment variable!
1416
1417- Python bytecode files (*.pyc and *.pyo) are not compatible between
1418releases.
1419
1420
1421Overview of Changes Since 1.6
1422-----------------------------
1423
1424There are many new modules (including brand new XML support through
1425the xml package, and i18n support through the gettext module); a list
1426of all new modules is included below. Lots of bugs have been fixed.
1427
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001428The process for making major new changes to the language has changed
1429since Python 1.6. Enhancements must now be documented by a Python
1430Enhancement Proposal (PEP) before they can be accepted.
1431
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001432There are several important syntax enhancements, described in more
1433detail below:
1434
1435 - Augmented assignment, e.g. x += 1
1436
1437 - List comprehensions, e.g. [x**2 for x in range(10)]
1438
1439 - Extended import statement, e.g. import Module as Name
1440
1441 - Extended print statement, e.g. print >> file, "Hello"
1442
1443Other important changes:
1444
1445 - Optional collection of cyclical garbage
1446
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001447Python Enhancement Proposal (PEP)
1448---------------------------------
1449
1450PEP stands for Python Enhancement Proposal. A PEP is a design
1451document providing information to the Python community, or describing
1452a new feature for Python. The PEP should provide a concise technical
1453specification of the feature and a rationale for the feature.
1454
1455We intend PEPs to be the primary mechanisms for proposing new
1456features, for collecting community input on an issue, and for
1457documenting the design decisions that have gone into Python. The PEP
1458author is responsible for building consensus within the community and
1459documenting dissenting opinions.
1460
1461The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001462
1463Augmented Assignment
1464--------------------
1465
1466This must have been the most-requested feature of the past years!
1467Eleven new assignment operators were added:
1468
Guido van Rossume905e952000-09-05 12:42:46 +00001469 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001470
1471For example,
1472
1473 A += B
1474
1475is similar to
1476
1477 A = A + B
1478
1479except that A is evaluated only once (relevant when A is something
1480like dict[index].attr).
1481
1482However, if A is a mutable object, A may be modified in place. Thus,
1483if A is a number or a string, A += B has the same effect as A = A+B
1484(except A is only evaluated once); but if a is a list, A += B has the
1485same effect as A.extend(B)!
1486
1487Classes and built-in object types can override the new operators in
1488order to implement the in-place behavior; the not-in-place behavior is
1489used automatically as a fallback when an object doesn't implement the
1490in-place behavior. For classes, the method name is derived from the
1491method name for the corresponding not-in-place operator by inserting
1492an 'i' in front of the name, e.g. __iadd__ implements in-place
1493__add__.
1494
1495Augmented assignment was implemented by Thomas Wouters.
1496
1497
1498List Comprehensions
1499-------------------
1500
1501This is a flexible new notation for lists whose elements are computed
1502from another list (or lists). The simplest form is:
1503
1504 [<expression> for <variable> in <sequence>]
1505
Guido van Rossum56db0952000-09-06 23:34:25 +00001506For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001507This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001508
1509You can also add a condition:
1510
1511 [<expression> for <variable> in <sequence> if <condition>]
1512
1513For example, [w for w in words if w == w.lower()] would yield the list
1514of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001515than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001516
1517You can also have nested for loops and more than one 'if' clause. For
1518example, here's a function that flattens a sequence of sequences::
1519
1520 def flatten(seq):
1521 return [x for subseq in seq for x in subseq]
1522
1523 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1524
1525This prints
1526
1527 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1528
1529List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001530Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001531
1532
1533Extended Import Statement
1534-------------------------
1535
1536Many people have asked for a way to import a module under a different
1537name. This can be accomplished like this:
1538
1539 import foo
1540 bar = foo
1541 del foo
1542
1543but this common idiom gets old quickly. A simple extension of the
1544import statement now allows this to be written as follows:
1545
1546 import foo as bar
1547
1548There's also a variant for 'from ... import':
1549
1550 from foo import bar as spam
1551
1552This also works with packages; e.g. you can write this:
1553
1554 import test.regrtest as regrtest
1555
1556Note that 'as' is not a new keyword -- it is recognized only in this
1557context (this is only possible because the syntax for the import
1558statement doesn't involve expressions).
1559
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001560Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001561
1562
1563Extended Print Statement
1564------------------------
1565
1566Easily the most controversial new feature, this extension to the print
1567statement adds an option to make the output go to a different file
1568than the default sys.stdout.
1569
1570For example, to write an error message to sys.stderr, you can now
1571write:
1572
1573 print >> sys.stderr, "Error: bad dog!"
1574
1575As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001576evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001577
1578 print >> None, "Hello world"
1579
1580is equivalent to
1581
1582 print "Hello world"
1583
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001584Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001585
1586
1587Optional Collection of Cyclical Garbage
1588---------------------------------------
1589
1590Python is now equipped with a garbage collector that can hunt down
1591cyclical references between Python objects. It's no replacement for
1592reference counting; in fact, it depends on the reference counts being
1593correct, and decides that a set of objects belong to a cycle if all
1594their reference counts can be accounted for from their references to
1595each other. This devious scheme was first proposed by Eric Tiedemann,
1596and brought to implementation by Neil Schemenauer.
1597
1598There's a module "gc" that lets you control some parameters of the
1599garbage collection. There's also an option to the configure script
1600that lets you enable or disable the garbage collection. In 2.0b1,
1601it's on by default, so that we (hopefully) can collect decent user
1602experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001603performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001604off by default in the final 2.0 release.
1605
1606
1607Smaller Changes
1608---------------
1609
1610A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1611map(None, seq1, seq2, ...) when the sequences have the same length;
1612i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1613the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001614zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001615
1616sys.version_info is a tuple (major, minor, micro, level, serial).
1617
1618Dictionaries have an odd new method, setdefault(key, default).
1619dict.setdefault(key, default) returns dict[key] if it exists; if not,
1620it sets dict[key] to default and returns that value. Thus:
1621
1622 dict.setdefault(key, []).append(item)
1623
1624does the same work as this common idiom:
1625
1626 if not dict.has_key(key):
1627 dict[key] = []
1628 dict[key].append(item)
1629
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001630There are two new variants of SyntaxError that are raised for
1631indentation-related errors: IndentationError and TabError.
1632
1633Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1634escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001635
1636The limits on the size of expressions and file in Python source code
1637have been raised from 2**16 to 2**32. Previous versions of Python
1638were limited because the maximum argument size the Python VM accepted
1639was 2**16. This limited the size of object constructor expressions,
1640e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1641limit was raised thanks to a patch by Charles Waldman that effectively
1642fixes the problem. It is now much more likely that you will be
1643limited by available memory than by an arbitrary limit in Python.
1644
1645The interpreter's maximum recursion depth can be modified by Python
1646programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1647limit is the maximum number of recursive calls that can be made by
1648Python code. The limit exists to prevent infinite recursion from
1649overflowing the C stack and causing a core dump. The default value is
16501000. The maximum safe value for a particular platform can be found
1651by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001652
1653New Modules and Packages
1654------------------------
1655
1656atexit - for registering functions to be called when Python exits.
1657
1658imputil - Greg Stein's alternative API for writing custom import
1659hooks.
1660
1661pyexpat - an interface to the Expat XML parser, contributed by Paul
1662Prescod.
1663
1664xml - a new package with XML support code organized (so far) in three
1665subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1666would fill a volume. There's a special feature whereby a
1667user-installed package named _xmlplus overrides the standard
1668xmlpackage; this is intended to give the XML SIG a hook to distribute
1669backwards-compatible updates to the standard xml package.
1670
1671webbrowser - a platform-independent API to launch a web browser.
1672
1673
Guido van Rossume905e952000-09-05 12:42:46 +00001674Changed Modules
1675---------------
1676
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001677array -- new methods for array objects: count, extend, index, pop, and
1678remove
1679
1680binascii -- new functions b2a_hex and a2b_hex that convert between
1681binary data and its hex representation
1682
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001683calendar -- Many new functions that support features including control
1684over which day of the week is the first day, returning strings instead
1685of printing them. Also new symbolic constants for days of week,
1686e.g. MONDAY, ..., SUNDAY.
1687
1688cgi -- FieldStorage objects have a getvalue method that works like a
1689dictionary's get method and returns the value attribute of the object.
1690
1691ConfigParser -- The parser object has new methods has_option,
1692remove_section, remove_option, set, and write. They allow the module
1693to be used for writing config files as well as reading them.
1694
1695ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001696optionally support the RFC 959 REST command.
1697
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001698gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001699
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001700httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1701the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001702
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001703locale -- implement getdefaultlocale for Win32 and Macintosh
1704
1705marshal -- no longer dumps core when marshaling deeply nested or
1706recursive data structures
1707
1708os -- new functions isatty, seteuid, setegid, setreuid, setregid
1709
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001710os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1711support under Unix.
1712
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001713os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001714
1715os.path -- fix semantics of os.path.commonprefix
1716
1717smtplib -- support for sending very long messages
1718
1719socket -- new function getfqdn()
1720
1721readline -- new functions to read, write and truncate history files.
1722The readline section of the library reference manual contains an
1723example.
1724
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001725select -- add interface to poll system call
1726
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001727shutil -- new copyfileobj function
1728
1729SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1730HTTP server.
1731
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001732Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001733
1734urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001735e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001736
1737whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001738
1739
1740Obsolete Modules
1741----------------
1742
1743None. However note that 1.6 made a whole slew of modules obsolete:
1744stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1745poly, zmod, strop, util, whatsound.
1746
1747
1748Changed, New, Obsolete Tools
1749----------------------------
1750
Tim Peters8b092332000-09-05 20:15:25 +00001751None.
Guido van Rossume905e952000-09-05 12:42:46 +00001752
1753
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001754C-level Changes
1755---------------
1756
1757Several cleanup jobs were carried out throughout the source code.
1758
1759All C code was converted to ANSI C; we got rid of all uses of the
1760Py_PROTO() macro, which makes the header files a lot more readable.
1761
1762Most of the portability hacks were moved to a new header file,
1763pyport.h; several other new header files were added and some old
1764header files were removed, in an attempt to create a more rational set
1765of header files. (Few of these ever need to be included explicitly;
1766they are all included by Python.h.)
1767
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001768Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001769and Win64, especially for the new Intel Itanium processor. Mick also
1770added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001771
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001772The C APIs to return an object's size have been update to consistently
1773use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1774previous versions, the abstract interfaces used PyXXX_Length and the
1775concrete interfaces used PyXXX_Size. The old names,
1776e.g. PyObject_Length, are still available for backwards compatibility
1777at the API level, but are deprecated.
1778
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001779The PyOS_CheckStack function has been implemented on Windows by
1780Fredrik Lundh. It prevents Python from failing with a stack overflow
1781on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001782
1783The GC changes resulted in creation of two new slots on object,
1784tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001785the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001786
1787The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001788C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001789
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001790PyErr_Format has been updated to automatically calculate the size of
1791the buffer needed to hold the formatted result string. This change
1792prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001793
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001794New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001795
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001796PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1797that are the same as their non-Ex counterparts except they take an
1798extra flag argument that tells them to close the file when done.
1799
1800XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001801
Tim Peters8b092332000-09-05 20:15:25 +00001802
1803Windows Changes
1804---------------
1805
1806New popen2/popen3/peopen4 in os module (see Changed Modules above).
1807
1808os.popen is much more usable on Windows 95 and 98. See Microsoft
1809Knowledge Base article Q150956. The Win9x workaround described there
1810is implemented by the new w9xpopen.exe helper in the root of your
1811Python installation. Note that Python uses this internally; it is not
1812a standalone program.
1813
1814Administrator privileges are no longer required to install Python
1815on Windows NT or Windows 2000. If you have administrator privileges,
1816Python's registry info will be written under HKEY_LOCAL_MACHINE.
1817Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001818under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001819uses of Python, but will prevent some advanced uses from working
1820(for example, running a Python script as an NT service, or possibly
1821from CGI).
1822
1823[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1824installer; instead, it installs the needed Tcl/Tk files directly in the
1825Python directory. If you already have a Tcl/Tk installation, this
1826wastes some disk space (about 4 Megs) but avoids problems with
1827conflicting Tcl/Tk installations, and makes it much easier for Python
1828to ensure that Tcl/Tk can find all its files.
1829
1830[This was new in 1.6] The Windows installer now installs by default in
1831\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1832
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001833
1834Updates to the changes between 1.5.2 and 1.6
1835--------------------------------------------
1836
1837The 1.6 NEWS file can't be changed after the release is done, so here
1838is some late-breaking news:
1839
1840New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1841and changes to getlocale() and setlocale().
1842
1843The new module is now enabled per default.
1844
1845It is not true that the encodings codecs cannot be used for normal
1846strings: the string.encode() (which is also present on 8-bit strings
1847!) allows using them for 8-bit strings too, e.g. to convert files from
1848cp1252 (Windows) to latin-1 or vice-versa.
1849
1850Japanese codecs are available from Tamito KAJIYAMA:
1851http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1852
1853
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001854======================================================================