blob: 1f971cd40c94554dad02d2d604e59c161ce8bf6e [file] [log] [blame]
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 Peters8572b4f2001-05-06 01:05:02 +000020 map(), filter(), reduce()
21 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
22 max(), min()
23 zip()
Tim Petersde9725f2001-05-05 10:06:17 +000024 .join() method of strings
Tim Peters75f8e352001-05-05 11:33:43 +000025 'x in y' and 'x not in y' (PySequence_Contains() in C API)
26 operator.countOf() (PySequence_Count() in C API)
Tim Peters75f8e352001-05-05 11:33:43 +000027
Tim Petersf553f892001-05-01 20:45:31 +000028
Guido van Rossumffe13be2001-04-16 18:46:45 +000029What's New in Python 2.1 (final)?
30=================================
31
32We only changed a few things since the last release candidate, all in
33Python library code:
34
35- A bug in the locale module was fixed that affected locales which
36 define no grouping for numeric formatting.
37
38- A few bugs in the weakref module's implementations of weak
39 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
40 and the test suite was updated to check for these bugs.
41
42- An old bug in the os.path.walk() function (introduced in Python
43 2.0!) was fixed: a non-existent file would cause an exception
44 instead of being ignored.
45
46- Fixed a few bugs in the new symtable module found by Neil Norwitz's
47 PyChecker.
48
49
Guido van Rossum5b08f132001-04-16 02:05:23 +000050What's New in Python 2.1c2?
51===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +000052
Guido van Rossum5b08f132001-04-16 02:05:23 +000053A flurry of small changes, and one showstopper fixed in the nick of
54time made it necessary to release another release candidate. The list
55here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +000056
Guido van Rossum5b08f132001-04-16 02:05:23 +000057Core
Guido van Rossum4fb60362001-04-13 00:46:14 +000058
Guido van Rossum5b08f132001-04-16 02:05:23 +000059- Tim discovered a nasty bug in the dictionary code, caused by
60 PyDict_Next() calling dict_resize(), and the GC code's use of
61 PyDict_Next() violating an assumption in dict_items(). This was
62 fixed with considerable amounts of band-aid, but the net effect is a
63 saner and more robust implementation.
64
65- Made a bunch of symbols static that were accidentally global.
66
67Build and Ports
68
69- The setup.py script didn't check for a new enough version of zlib
70 (1.1.3 is needed). Now it does.
71
72- Changed "make clean" target to also remove shared libraries.
73
74- Added a more general warning about the SGI Irix optimizer to README.
75
76Library
77
78- Fix a bug in urllib.basejoin("http://host", "../file.html") which
79 omitted the slash between host and file.html.
80
81- The mailbox module's _Mailbox class contained a completely broken
82 and undocumented seek() method. Ripped it out.
83
84- Fixed a bunch of typos in various library modules (urllib2, smtpd,
85 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
86
87- Fixed a few last-minute bugs in unittest.
88
89Extensions
90
91- Reverted the patch to the OpenSSL code in socketmodule.c to support
92 RAND_status() and the EGD, and the subsequent patch that tried to
93 fix it for pre-0.9.5 versions; the problem with the patch is that on
94 some systems it issues a warning whenever socket is imported, and
95 that's unacceptable.
96
97Tests
98
99- Fixed the pickle tests to work with "import test.test_pickle".
100
101- Tweaked test_locale.py to actually run the test Windows.
102
103- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
104 not "wb" (which is not a valid mode at all).
105
106- Fix pstats browser crashes. Import readline if it exists to make
107 the user interface nicer.
108
109- Add "import thread" to the top of test modules that import the
110 threading module (test_asynchat and test_threadedtempfile). This
111 prevents test failures caused by a broken threading module resulting
112 from a previously caught failed import.
113
114- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
115 needed on some platforms (e.g. Solaris 8) when the tests are run
116 twice in succession.
117
118- Skip rather than fail test_sunaudiodev if no audio device is found.
119
120
121What's New in Python 2.1c1?
122===========================
123
124This list was significantly updated when 2.1c2 was released; the 2.1c1
125release didn't mention most changes that were actually part of 2.1c1:
126
127Legal
128
129- Copyright was assigned to the Python Software Foundation (PSF) and a
130 PSF license (very similar to the CNRI license) was added.
131
132- The CNRI copyright notice was updated to include 2001.
133
134Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000135
Guido van Rossumc9932722001-04-12 02:31:27 +0000136- After a public outcry, assignment to __debug__ is no longer illegal;
137 instead, a warning is issued. It will become illegal in 2.2.
138
Guido van Rossum5b08f132001-04-16 02:05:23 +0000139- Fixed a core dump with "%#x" % 0, and changed the semantics so that
140 "%#x" now always prepends "0x", even if the value is zero.
141
142- Fixed some nits in the bytecode compiler.
143
144- Fixed core dumps when calling certain kinds of non-functions.
145
146- Fixed various core dumps caused by reference count bugs.
147
148Build and Ports
149
150- Use INSTALL_SCRIPT to install script files.
151
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000152- New port: SCO Unixware 7, by Billy G. Allie.
153
Guido van Rossum5b08f132001-04-16 02:05:23 +0000154- Updated RISCOS port.
155
156- Updated BeOS port and notes.
157
158- Various other porting problems resolved.
159
160Library
161
162- The TERMIOS and SOCKET modules are now truly obsolete and
163 unnecessary. Their symbols are incorporated in the termios and
164 socket modules.
165
166- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
167 better tests for pickling.
168
169- threading: make Condition.wait() robust against KeyboardInterrupt.
170
171- zipfile: add support to zipfile to support opening an archive
172 represented by an open file rather than a file name. Fix bug where
173 the archive was not properly closed. Fixed a bug in this bugfix
174 where flush() was called for a read-only file.
175
176- imputil: added an uninstall() method to the ImportManager.
177
178- Canvas: fixed bugs in lower() and tkraise() methods.
179
180- SocketServer: API change (added overridable close_request() method)
181 so that the TCP server can explicitly close the request.
182
183- pstats: Eric Raymond added a simple interactive statistics browser,
184 invoked when the module is run as a script.
185
186- locale: fixed a problem in format().
187
188- webbrowser: made it work when the BROWSER environment variable has a
189 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
190 KDE 2. Fixed some other nits.
191
192- unittest: changes to allow using a different exception than
193 AssertionError, and added a few more function aliases. Some other
194 small changes.
195
196- urllib, urllib2: fixed redirect problems and a coupleof other nits.
197
198- asynchat: fixed a critical bug in asynchat that slipped through the
199 2.1b2 release. Fixed another rare bug.
200
201- Fix some unqualified except: clauses (always a bad code example).
202
203XML
204
205- pyexpat: new API get_version_string().
206
207- Fixed some minidom bugs.
208
209Extensions
210
211- Fixed a core dump in _weakref. Removed the weakref.mapping()
212 function (it adds nothing to the API).
213
214- Rationalized the use of header files in the readline module, to make
215 it compile (albeit with some warnings) with the very recent readline
216 4.2, without breaking for earlier versions.
217
218- Hopefully fixed a buffering problem in linuxaudiodev.
219
220- Attempted a fix to make the OpenSSL support in the socket module
221 work again with pre-0.9.5 versions of OpenSSL.
222
223Tests
224
225- Added a test case for asynchat and asyncore.
226
227- Removed coupling between tests where one test failing could break
228 another.
229
230Tools
231
232- Ping added an interactive help browser to pydoc, fixed some nits
233 in the rest of the pydoc code, and added some features to his
234 inspect module.
235
236- An updated python-mode.el version 4.1 which integrates Ken
237 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
238 much nicer in XEmacs and Emacs. When stepping through your program
239 with pdb, in either the shell window or the *Python* window, the
240 source file and line will be tracked by an arrow. Very cool!
241
242- IDLE: syntax warnings in interactive mode are changed into errors.
243
244- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000245 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000246
247- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000248
Barry Warsaw11e89c72001-04-11 20:37:57 +0000249
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000250What's New in Python 2.1 beta 2?
251================================
252
Guido van Rossum053ae352001-03-22 14:17:21 +0000253(Unlisted are many fixed bugs, more documentation, etc.)
254
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000255Core language, builtins, and interpreter
256
Guido van Rossum053ae352001-03-22 14:17:21 +0000257- The nested scopes work (enabled by "from __future__ import
258 nested_scopes") is completed; in particular, the future now extends
259 into code executed through exec, eval() and execfile(), and into the
260 interactive interpreter.
261
262- When calling a base class method (e.g. BaseClass.__init__(self)),
263 this is now allowed even if self is not strictly spoken a class
264 instance (e.g. when using metaclasses or the Don Beaudry hook).
265
266- Slice objects are now comparable but not hashable; this prevents
267 dict[:] from being accepted but meaningless.
268
269- Complex division is now calculated using less braindead algorithms.
270 This doesn't change semantics except it's more likely to give useful
271 results in extreme cases. Complex repr() now uses full precision
272 like float repr().
273
274- sgmllib.py now calls handle_decl() for simple <!...> declarations.
275
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000276- It is illegal to assign to the name __debug__, which is set when the
277 interpreter starts. It is effectively a compile-time constant.
278
279- A warning will be issued if a global statement for a variable
280 follows a use or assignment of that variable.
281
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000282Standard library
283
Guido van Rossum053ae352001-03-22 14:17:21 +0000284- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
285 inspired by JUnit), is now part of the standard library. You now
286 have a choice of two testing frameworks: unittest requires you to
287 write testcases as separate code, doctest gathers them from
288 docstrings. Both approaches have their advantages and
289 disadvantages.
290
291- A new module Tix was added, which wraps the Tix extension library
292 for Tk. With that module, it is not necessary to statically link
293 Tix with _tkinter, since Tix will be loaded with Tcl's "package
294 require" command. See Demo/tix/.
295
296- tzparse.py is now obsolete.
297
298- In gzip.py, the seek() and tell() methods are removed -- they were
299 non-functional anyway, and it's better if callers can test for their
300 existence with hasattr().
301
302Python/C API
303
304- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
305 that's already in the dictionary during a PyDict_Next() iteration.
306 This used to fail occasionally when a dictionary resize operation
307 could be triggered that would rehash all the keys. All other
308 modifications to the dictionary are still off-limits during a
309 PyDict_Next() iteration!
310
311- New extended APIs related to passing compiler variables around.
312
313- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
314 implement isinstance() and issubclass().
315
316- Py_BuildValue() now has a "D" conversion to create a Python complex
317 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000318
Fred Drake4e262a92001-03-22 18:26:47 +0000319- Extensions types which support weak references must now set the
320 field allocated for the weak reference machinery to NULL themselves;
321 this is done to avoid the cost of checking each object for having a
322 weakly referencable type in PyObject_INIT(), since most types are
323 not weakly referencable.
324
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000325- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
326 free variables and cell variables to and from the frame's f_locals.
327
328- Variants of several functions defined in pythonrun.h have been added
329 to support the nested_scopes future statement. The variants all end
330 in Flags and take an extra argument, a PyCompilerFlags *; examples:
331 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
332 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000333 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000334
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000335Distutils
336
337- the sdist command now writes a PKG-INFO file, as described in PEP 241,
338 into the release tree.
339
Tim Peters0e57abf2001-05-02 07:39:38 +0000340- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000341 (an uninstaller, more customization of the installer's display)
342
343- from Jack Jansen: added Mac-specific code to generate a dialog for
344 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000345 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000346 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000347
348- added 'platforms' and 'keywords' to the set of metadata that can be
349 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000350
351- applied patches from Jason Tishler to make the compiler class work with
352 Cygwin.
353
354
Tim Peters2fe289a2001-03-01 22:19:38 +0000355What's New in Python 2.1 beta 1?
356================================
Tim Petersd66595f2001-02-04 03:09:53 +0000357
358Core language, builtins, and interpreter
359
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000360- Following an outcry from the community about the amount of code
361 broken by the nested scopes feature introduced in 2.1a2, we decided
362 to make this feature optional, and to wait until Python 2.2 (or at
363 least 6 months) to make it standard. The option can be enabled on a
364 per-module basis by adding "from __future__ import nested_scopes" at
365 the beginning of a module (before any other statements, but after
366 comments and an optional docstring). See PEP 236 (Back to the
367 __future__) for a description of the __future__ statement. PEP 227
368 (Statically Nested Scopes) has been updated to reflect this change,
369 and to clarify the semantics in a number of endcases.
370
371- The nested scopes code, when enabled, has been hardened, and most
372 bugs and memory leaks in it have been fixed.
373
374- Compile-time warnings are now generated for a number of conditions
375 that will break or change in meaning when nested scopes are enabled:
376
377 - Using "from...import *" or "exec" without in-clause in a function
378 scope that also defines a lambda or nested function with one or
379 more free (non-local) variables. The presence of the import* or
380 bare exec makes it impossible for the compiler to determine the
381 exact set of local variables in the outer scope, which makes it
382 impossible to determine the bindings for free variables in the
383 inner scope. To avoid the warning about import *, change it into
384 an import of explicitly name object, or move the import* statement
385 to the global scope; to avoid the warning about bare exec, use
386 exec...in... (a good idea anyway -- there's a possibility that
387 bare exec will be deprecated in the future).
388
389 - Use of a global variable in a nested scope with the same name as a
390 local variable in a surrounding scope. This will change in
391 meaning with nested scopes: the name in the inner scope will
392 reference the variable in the outer scope rather than the global
393 of the same name. To avoid the warning, either rename the outer
394 variable, or use a global statement in the inner function.
395
Neil Schemenauera35c6882001-02-27 04:45:05 +0000396- An optional object allocator has been included. This allocator is
397 optimized for Python objects and should be faster and use less memory
398 than the standard system allocator. It is not enabled by default
399 because of possible thread safety problems. The allocator is only
400 protected by the Python interpreter lock and it is possible that some
401 extension modules require a thread safe allocator. The object
402 allocator can be enabled by providing the "--with-pymalloc" option to
403 configure.
404
Tim Petersd66595f2001-02-04 03:09:53 +0000405Standard library
406
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000407- pyexpat now detects the expat version if expat.h defines it. A
408 number of additional handlers are provided, which are only available
409 since expat 1.95. In addition, the methods SetParamEntityParsing and
410 GetInputContext of Parser objects are available with 1.95.x
411 only. Parser objects now provide the ordered_attributes and
412 specified_attributes attributes. A new module expat.model was added,
413 which offers a number of additional constants if 1.95.x is used.
414
415- xml.dom offers the new functions registerDOMImplementation and
416 getDOMImplementation.
417
418- xml.dom.minidom offers a toprettyxml method. A number of DOM
419 conformance issues have been resolved. In particular, Element now
420 has an hasAttributes method, and the handling of namespaces was
421 improved.
422
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000423- Ka-Ping Yee contributed two new modules: inspect.py, a module for
424 getting information about live Python code, and pydoc.py, a module
425 for interactively converting docstrings to HTML or text.
426 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000427 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000428 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
429 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000430
Tim Peters1eff7962001-03-01 02:31:33 +0000431- New library module difflib.py, primarily packaging the SequenceMatcher
432 class at the heart of the popular ndiff.py file-comparison tool.
433
434- doctest.py (a framework for verifying Python code examples in docstrings)
435 is now part of the std library.
436
Tim Petersd66595f2001-02-04 03:09:53 +0000437Windows changes
438
Guido van Rossume3955a82001-03-02 14:05:59 +0000439- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
440 small GUI that lets you browse the module docstrings using your
441 default web browser.
442
Tim Peters1eff7962001-03-01 02:31:33 +0000443- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
444 Platforms) is implemented. See
445
446 http://python.sourceforge.net/peps/pep-0235.html
447
448 for full details, especially the "Current Lower-Left Semantics" section.
449 The new Windows import rules are simpler than before:
450
451 A. If the PYTHONCASEOK environment variable exists, same as
452 before: silently accept the first case-insensitive match of any
453 kind; raise ImportError if none found.
454
455 B. Else search sys.path for the first case-sensitive match; raise
456 ImportError if none found.
457
458 The same rules have been implented on other platforms with case-
459 insensitive but case-preserving filesystems too (including Cygwin, and
460 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000461
Tim Peters25a9ce32001-02-19 07:06:36 +0000462- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
463 what it's supposed to do (and does do under NT and 2000) via direct
464 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000465 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000466 all Win9x systems before.
467
Tim Peters1eff7962001-03-01 02:31:33 +0000468- Build: Subproject _test (effectively) renamed to _testcapi.
469
Tim Peters2fe289a2001-03-01 22:19:38 +0000470New platforms
471
472- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
473 Thanks to Steven Majewski!
474
475- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
476 Tishler!
477
Guido van Rossum9089b272001-03-02 06:49:50 +0000478- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
479 Schwertberger! See RISCOS/README for more information -- it seems
480 that because of the bizarre filename conventions on RISCOS, no port
481 to that platform is easy. Note that the new variable os.endsep is
482 silently supported in order to make life easier on this platform,
483 but we don't advertise it because it's not worth for most folks to
484 care about RISCOS portability.
485
Tim Peters25a9ce32001-02-19 07:06:36 +0000486
Tim Petersd7b5e882001-01-25 03:36:26 +0000487What's New in Python 2.1 alpha 2?
488=================================
Tim Peters40ead762001-01-27 05:35:26 +0000489
Tim Petersd7b5e882001-01-25 03:36:26 +0000490Core language, builtins, and interpreter
491
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000492- Scopes nest. If a name is used in a function or class, but is not
493 local, the definition in the nearest enclosing function scope will
494 be used. One consequence of this change is that lambda statements
495 could reference variables in the namespaces where the lambda is
496 defined. In some unusual cases, this change will break code.
497
498 In all previous version of Python, names were resolved in exactly
499 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000500 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000501 function A is defined within a function B, the names bound in B are
502 not visible in A. The new rules make names bound in B visible in A,
503 unless A contains a name binding that hides the binding in B.
504
505 Section 4.1 of the reference manual describes the new scoping rules
506 in detail. The test script in Lib/test/test_scope.py demonstrates
507 some of the effects of the change.
508
509 The new rules will cause existing code to break if it defines nested
510 functions where an outer function has local variables with the same
511 name as globals or builtins used by the inner function. Example:
512
513 def munge(str):
514 def helper(x):
515 return str(x)
516 if type(str) != type(''):
517 str = helper(str)
518 return str.strip()
519
520 Under the old rules, the name str in helper() is bound to the
521 builtin function str(). Under the new rules, it will be bound to
522 the argument named str and an error will occur when helper() is
523 called.
524
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000525- The compiler will report a SyntaxError if "from ... import *" occurs
526 in a function or class scope. The language reference has documented
527 that this case is illegal, but the compiler never checked for it.
528 The recent introduction of nested scope makes the meaning of this
529 form of name binding ambiguous. In a future release, the compiler
530 may allow this form when there is no possibility of ambiguity.
531
Tim Peters40ead762001-01-27 05:35:26 +0000532- repr(string) is easier to read, now using hex escapes instead of octal,
533 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
534
535 >>> "\texample \r\n" + chr(0) + chr(255)
536 '\texample \r\n\x00\xff' # in 2.1
537 '\011example \015\012\000\377' # in 2.0
538
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000539- Functions are now compared and hashed by identity, not by value, since
540 the func_code attribute is writable.
541
Fred Drakefb9d7122001-02-01 20:00:40 +0000542- Weak references (PEP 205) have been added. This involves a few
543 changes in the core, an extension module (_weakref), and a Python
544 module (weakref). The weakref module is the public interface. It
545 includes support for "explicit" weak references, proxy objects, and
546 mappings with weakly held values.
547
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000548- A 'continue' statement can now appear in a try block within the body
549 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000550 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000551
Tim Petersd7b5e882001-01-25 03:36:26 +0000552Standard library
553
Barry Warsaw30dbd142001-01-31 22:14:01 +0000554- mailbox.py now has a new class, PortableUnixMailbox which is
555 identical to UnixMailbox but uses a more portable scheme for
556 determining From_ separators. Also, the constructors for all the
557 classes in this module have a new optional `factory' argument, which
558 is a callable used when new message classes must be instantiated by
559 the next() method.
560
Tim Petersd7b5e882001-01-25 03:36:26 +0000561- random.py is now self-contained, and offers all the functionality of
562 the now-deprecated whrandom.py. See the docs for details. random.py
563 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000564 and restoring the internal state of the generator; and jumpahead(n),
565 for quickly forcing the internal state to be the same as if n calls to
566 random() had been made. The latter is particularly useful for multi-
567 threaded programs, creating one instance of the random.Random() class for
568 each thread, then using .jumpahead() to force each instance to use a
569 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000570
Tim Peters0de88fc2001-02-01 04:59:18 +0000571- random.py's seed() function is new. For bit-for-bit compatibility with
572 prior releases, use the whseed function instead. The new seed function
573 addresses two problems: (1) The old function couldn't produce more than
574 about 2**24 distinct internal states; the new one about 2**45 (the best
575 that can be done in the Wichmann-Hill generator). (2) The old function
576 sometimes produced identical internal states when passed distinct
577 integers, and there was no simple way to predict when that would happen;
578 the new one guarantees to produce distinct internal states for all
579 arguments in [0, 27814431486576L).
580
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000581- The socket module now supports raw packets on Linux. The socket
582 family is AF_PACKET.
583
Tim Peters9ea17ac2001-02-02 05:57:15 +0000584- test_capi.py is a start at running tests of the Python C API. The tests
585 are implemented by the new Modules/_testmodule.c.
586
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000587- A new extension module, _symtable, provides provisional access to the
588 internal symbol table used by the Python compiler. A higher-level
589 interface will be added on top of _symtable in a future release.
590
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000591- Removed the obsolete soundex module.
592
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000593- xml.dom.minidom now uses the standard DOM exceptions. Node supports
594 the isSameNode method; NamedNodeMap the get method.
595
596- xml.sax.expatreader supports the lexical handler property; it
597 generates comment, startCDATA, and endCDATA events.
598
Tim Petersee826f82001-01-31 19:39:44 +0000599Windows changes
600
601- Build procedure: the zlib project is built in a different way that
602 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000603 the zlib binary used. See PCbuild\readme.txt for details. Your old
604 zlib-related directories can be deleted; you'll need to download fresh
605 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000606
Tim Peters9ea17ac2001-02-02 05:57:15 +0000607- Build: New subproject _test for the benefit of test_capi.py (see above).
608
Tim Petersb16c56f2001-02-02 21:24:51 +0000609- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
610 interface to some Python compiler internals).
611
612- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000613 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000614
Tim Petersa3a3a032000-11-30 05:22:44 +0000615What's New in Python 2.1 alpha 1?
616=================================
617
618Core language, builtins, and interpreter
619
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000620- There is a new Unicode companion to the PyObject_Str() API
621 called PyObject_Unicode(). It behaves in the same way as the
622 former, but assures that the returned value is an Unicode object
623 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000624
Guido van Rossumf98eda02001-01-17 15:54:45 +0000625- The comparison operators support "rich comparison overloading" (PEP
626 207). C extension types can provide a rich comparison function in
627 the new tp_richcompare slot in the type object. The cmp() function
628 and the C function PyObject_Compare() first try the new rich
629 comparison operators before trying the old 3-way comparison. There
630 is also a new C API PyObject_RichCompare() (which also falls back on
631 the old 3-way comparison, but does not constrain the outcome of the
632 rich comparison to a Boolean result).
633
634 The rich comparison function takes two objects (at least one of
635 which is guaranteed to have the type that provided the function) and
636 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
637 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
638 object, which may be NotImplemented (in which case the tp_compare
639 slot function is used as a fallback, if defined).
640
641 Classes can overload individual comparison operators by defining one
642 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000643 __ge__. There are no explicit "reflected argument" versions of
644 these; instead, __lt__ and __gt__ are each other's reflection,
645 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
646 reflection (similar at the C level). No other implications are
647 made; in particular, Python does not assume that == is the Boolean
648 inverse of !=, or that < is the Boolean inverse of >=. This makes
649 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000650
651 Classes or types that want to implement (in)equality tests but not
652 the ordering operators (i.e. unordered types) should implement ==
653 and !=, and raise an error for the ordering operators.
654
Guido van Rossuma88479f2001-01-18 14:28:08 +0000655 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000656 Boolean; e.g. a matrix type might want to return a matrix of bits
657 for A < B, giving elementwise comparisons. Such types should ensure
658 that any interpretation of their value in a Boolean context raises
659 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
660 at the C level) to always raise an exception.
661
Guido van Rossuma88479f2001-01-18 14:28:08 +0000662- Complex numbers use rich comparisons to define == and != but raise
663 an exception for <, <=, > and >=. Unfortunately, this also means
664 that cmp() of two complex numbers raises an exception when the two
665 numbers differ. Since it is not mathematically meaningful to compare
666 complex numbers except for equality, I hope that this doesn't break
667 too much code.
668
Tim Peters3389f192001-02-18 08:48:49 +0000669- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000670 not defined by the language, other than that it's arbitrary but
671 consistent (see the Reference Manual). An implementation detail changed
672 in 2.1a1 such that None now compares less than any other object. Code
673 relying on this new behavior (like code that relied on the previous
674 behavior) does so at its own risk.
675
Barry Warsaw573b5412001-01-15 20:43:18 +0000676- Functions and methods now support getting and setting arbitrarily
677 named attributes (PEP 232). Functions have a new __dict__
678 (a.k.a. func_dict) which hold the function attributes. Methods get
679 and set attributes on their underlying im_func. It is a TypeError
680 to set an attribute on a bound method.
681
Guido van Rossum051e3352001-01-15 19:11:10 +0000682- The xrange() object implementation has been improved so that
683 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
684 limitation that in this case len(xrange(sys.maxint)) can't be
685 calculated, but the common idiom "for i in xrange(sys.maxint)" will
686 work fine as long as the index i doesn't actually reach 2**31.
687 (Python uses regular ints for sequence and string indices; fixing
688 that is much more work.)
689
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000690- Two changes to from...import:
691
Guido van Rossumba381232001-02-03 15:06:40 +0000692 1) "from M import X" now works even if (after loading module M)
693 sys.modules['M'] is not a real module; it's basically a getattr()
694 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000695
696 2) "from M import *" now looks for M.__all__ to decide which names to
697 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
698 filters out names starting with '_' as before. Whether or not
699 __all__ exists, there's no restriction on the type of M.
700
Guido van Rossumf61f1662001-01-10 20:13:55 +0000701- File objects have a new method, xreadlines(). This is the fastest
702 way to iterate over all lines in a file:
703
704 for line in file.xreadlines():
705 ...do something to line...
706
707 See the xreadlines module (mentioned below) for how to do this for
708 other file-like objects.
709
710- Even if you don't use file.xreadlines(), you may expect a speedup on
711 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000712 quite a bit in platform-specific ways: on systems (like Linux) that
713 support flockfile(), getc_unlocked(), and funlockfile(), those are
714 used by default. On systems (like Windows) without getc_unlocked(),
715 a complicated (but still thread-safe) method using fgets() is used by
716 default.
717
Tim Petersd52269b2001-01-25 06:23:18 +0000718 You can force use of the fgets() method by #define'ing
719 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000720 getc_unlocked()).
721
Tim Petersd52269b2001-01-25 06:23:18 +0000722 You can force fgets() not to be used by #define'ing
723 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000724 test_bufio.py fails -- and let us know if it does!).
725
726- In addition, the fileinput module, while still slower than the other
727 methods on most platforms, has been sped up too, by using
728 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000729
730- Support for run-time warnings has been added, including a new
731 command line option (-W) to specify the disposition of warnings.
732 See the description of the warnings module below.
733
734- Extensive changes have been made to the coercion code. This mostly
735 affects extension modules (which can now implement mixed-type
736 numerical operators without having to use coercion), but
737 occasionally, in boundary cases the coercion semantics have changed
738 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000739 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000740 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000741 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000742
Guido van Rossumf98eda02001-01-17 15:54:45 +0000743- In connection with the coercion changes, a new built-in singleton
744 object, NotImplemented is defined. This can be returned for
745 operations that wish to indicate they are not implemented for a
746 particular combination of arguments. From C, this is
747 Py_NotImplemented.
748
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000749- The interpreter accepts now bytecode files on the command line even
750 if they do not have a .pyc or .pyo extension. On Linux, after executing
751
Martin v. Löwise214baa2001-02-04 22:37:56 +0000752import imp,sys,string
753magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
754reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
755open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000756
757 any byte code file can be used as an executable (i.e. as an argument
758 to execve(2)).
759
Tim Peters9940b802000-12-01 07:59:35 +0000760- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000761 character. In 1.6 and earlier, they never produced a sign,
762 and raised an error if the value of the long was too large
763 to fit in a Python int. In 2.0, they produced a sign if and
764 only if too large to fit in an int. This was inconsistent
765 across platforms (because the size of an int varies across
766 platforms), and inconsistent with hex() and oct(). Example:
767
768 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000769 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000770 'ffffffbe' # in 2.0 and before, on 32-bit machines
771 >>> hex(-0x42L)
772 '-0x42L' # in all versions of Python
773
Tim Peters9940b802000-12-01 07:59:35 +0000774 The behavior of %d formats for negative Python longs remains
775 the same as in 2.0 (although in 1.6 and before, they raised
776 an error if the long didn't fit in a Python int).
777
778 %u formats don't make sense for Python longs, but are allowed
779 and treated the same as %d in 2.1. In 2.0, a negative long
780 formatted via %u produced a sign if and only if too large to
781 fit in an int. In 1.6 and earlier, a negative long formatted
782 via %u raised an error if it was too big to fit in an int.
783
Guido van Rossum3661d392000-12-12 22:10:31 +0000784- Dictionary objects have an odd new method, popitem(). This removes
785 an arbitrary item from the dictionary and returns it (in the form of
786 a (key, value) pair). This can be useful for algorithms that use a
787 dictionary as a bag of "to do" items and repeatedly need to pick one
788 item. Such algorithms normally end up running in quadratic time;
789 using popitem() they can usually be made to run in linear time.
790
Tim Peters36cdad12000-12-29 02:06:45 +0000791Standard library
792
Thomas Woutersfe385252001-01-19 23:16:56 +0000793- In the time module, the time argument to the functions strftime,
794 localtime, gmtime, asctime and ctime is now optional, defaulting to
795 the current time (in the local timezone).
796
Guido van Rossumda91f222001-01-15 16:36:08 +0000797- The ftplib module now defaults to passive mode, which is deemed a
798 more useful default given that clients are often inside firewalls
799 these days. Note that this could break if ftplib is used to connect
800 to a *server* that is inside a firewall, from outside; this is
801 expected to be a very rare situation. To fix that, you can call
802 ftp.set_pasv(0).
803
Martin v. Löwis10a27872001-01-13 09:54:41 +0000804- The module site now treats .pth files not only for path configuration,
805 but also supports extensions to the initialization code: Lines starting
806 with import are executed.
807
Guido van Rossumf61f1662001-01-10 20:13:55 +0000808- There's a new module, warnings, which implements a mechanism for
809 issuing and filtering warnings. There are some new built-in
810 exceptions that serve as warning categories, and a new command line
811 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
812 turns warnings into errors). warnings.warn(message[, category])
813 issues a warning message; this can also be called from C as
814 PyErr_Warn(category, message).
815
816- A new module xreadlines was added. This exports a single factory
817 function, xreadlines(). The intention is that this code is the
818 absolutely fastest way to iterate over all lines in an open
819 file(-like) object:
820
821 import xreadlines
822 for line in xreadlines.xreadlines(file):
823 ...do something to line...
824
825 This is equivalent to the previous the speed record holder using
826 file.readlines(sizehint). Note that if file is a real file object
827 (as opposed to a file-like object), this is equivalent:
828
829 for line in file.xreadlines():
830 ...do something to line...
831
Tim Peters36cdad12000-12-29 02:06:45 +0000832- The bisect module has new functions bisect_left, insort_left,
833 bisect_right and insort_right. The old names bisect and insort
834 are now aliases for bisect_right and insort_right. XXX_right
835 and XXX_left methods differ in what happens when the new element
836 compares equal to one or more elements already in the list: the
837 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000838 right. Code that doesn't care where equal elements end up should
839 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000840
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000841- The new curses.panel module wraps the panel library that forms part
842 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
843
Guido van Rossumf61f1662001-01-10 20:13:55 +0000844- The SocketServer module now sets the allow_reuse_address flag by
845 default in the TCPServer class.
846
847- A new function, sys._getframe(), returns the stack frame pointer of
848 the caller. This is intended only as a building block for
849 higher-level mechanisms such as string interpolation.
850
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000851- The pyexpat module supports a number of new handlers, which are
852 available only in expat 1.2. If invocation of a callback fails, it
853 will report an additional frame in the traceback. Parser objects
854 participate now in garbage collection. If expat reports an unknown
855 encoding, pyexpat will try to use a Python codec; that works only
856 for single-byte charsets. The parser type objects is exposed as
857 XMLParserObject.
858
859- xml.dom now offers standard definitions for symbolic node type and
860 exception code constants, and a hierarchy of DOM exceptions. minidom
861 was adjusted to use them.
862
863- The conformance of xml.dom.minidom to the DOM specification was
864 improved. It detects a number of additional error cases; the
865 previous/next relationship works even when the tree is modified;
866 Node supports the normalize() method; NamedNodeMap, DocumentType and
867 DOMImplementation classes were added; Element supports the
868 hasAttribute and hasAttributeNS methods; and Text supports the splitText
869 method.
870
Guido van Rossumf61f1662001-01-10 20:13:55 +0000871Build issues
872
Guido van Rossum1e33bdc2001-01-23 03:17:00 +0000873- For Unix (and Unix-compatible) builds, configuration and building of
874 extension modules is now greatly automated. Rather than having to
875 edit the Modules/Setup file to indicate which modules should be
876 built and where their include files and libraries are, a
877 distutils-based setup.py script now takes care of building most
878 extension modules. All extension modules built this way are built
879 as shared libraries. Only a few modules that must be linked
880 statically are still listed in the Setup file; you won't need to
881 edit their configuration.
882
883- Python should now build out of the box on Cygwin. If it doesn't,
884 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000885
886- Python now always uses its own (renamed) implementation of getopt()
887 -- there's too much variation among C library getopt()
888 implementations.
889
890- C++ compilers are better supported; the CXX macro is always set to a
891 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +0000892
Tim Petersd92dfe02000-12-12 01:18:41 +0000893Windows changes
894
895- select module: By default under Windows, a select() call
896 can specify no more than 64 sockets. Python now boosts
897 this Microsoft default to 512. If you need even more than
898 that, see the MS docs (you'll need to #define FD_SETSIZE
899 and recompile Python from source).
900
Guido van Rossumf61f1662001-01-10 20:13:55 +0000901- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
902 subdirectory is no more!
903
Tim Petersa3a3a032000-11-30 05:22:44 +0000904
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000905What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +0000906=========================
Guido van Rossum61000331997-08-15 04:39:58 +0000907
Guido van Rossum8ed602b2000-09-01 22:34:33 +0000908Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000909changes are in the file HISTORY. If you are making the jump directly
910from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
911HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +0000912
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000913Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
914the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
915http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +0000916
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000917--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +0000918
919======================================================================
920
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000921What's new in 2.0 (since release candidate 1)?
922==============================================
923
924Standard library
925
926- The copy_reg module was modified to clarify its intended use: to
927 register pickle support for extension types, not for classes.
928 pickle() will raise a TypeError if it is passed a class.
929
930- Fixed a bug in gettext's "normalize and expand" code that prevented
931 it from finding an existing .mo file.
932
933- Restored support for HTTP/0.9 servers in httplib.
934
Tim Peters989b7b92000-10-16 20:24:53 +0000935- The math module was changed to stop raising OverflowError in case of
936 underflow, and return 0 instead in underflow cases. Whether Python
937 used to raise OverflowError in case of underflow was platform-
938 dependent (it did when the platform math library set errno to ERANGE
939 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000940
941- Fixed a bug in StringIO that occurred when the file position was not
942 at the end of the file and write() was called with enough data to
943 extend past the end of the file.
944
945- Fixed a bug that caused Tkinter error messages to get lost on
946 Windows. The bug was fixed by replacing direct use of
947 interp->result with Tcl_GetStringResult(interp).
948
949- Fixed bug in urllib2 that caused it to fail when it received an HTTP
950 redirect response.
951
952- Several changes were made to distutils: Some debugging code was
953 removed from util. Fixed the installer used when an external zip
954 program (like WinZip) is not found; the source code for this
955 installer is in Misc/distutils. check_lib() was modified to behave
956 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
957 test for whether installed modules are on sys.path was changed to
958 use both normcase() and normpath().
959
Jeremy Hyltond867a2c2000-10-16 20:41:38 +0000960- Several minor bugs were fixed in the xml package (the minidom,
961 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000962
963- The regression test driver (regrtest.py) behavior when invoked with
964 -l changed: It now reports a count of objects that are recognized as
965 garbage but not freed by the garbage collector.
966
Tim Peters989b7b92000-10-16 20:24:53 +0000967- The regression test for the math module was changed to test
968 exceptional behavior when the test is run in verbose mode. Python
969 cannot yet guarantee consistent exception behavior across platforms,
970 so the exception part of test_math is run only in verbose mode, and
971 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000972
973Internals
974
975- PyOS_CheckStack() has been disabled on Win64, where it caused
976 test_sre to fail.
977
978Build issues
979
980- Changed compiler flags, so that gcc is always invoked with -Wall and
981 -Wstrict-prototypes. Users compiling Python with GCC should see
982 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +0000983 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +0000984 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000985
Tim Petersa3a3a032000-11-30 05:22:44 +0000986- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000987
988Tools and other miscellany
989
990- The compiler in Tools/compiler was updated to support the new
991 language features introduced in 2.0: extended print statement, list
992 comprehensions, and augmented assignments. The new compiler should
993 also be backwards compatible with Python 1.5.2; the compiler will
994 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +0000995 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000996
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000997What's new in 2.0 release candidate 1 (since beta 2)?
998=====================================================
999
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001000What is release candidate 1?
1001
1002We believe that release candidate 1 will fix all known bugs that we
1003intend to fix for the 2.0 final release. This release should be a bit
1004more stable than the previous betas. We would like to see even more
1005widespread testing before the final release, so we are producing this
1006release candidate. The final release will be exactly the same unless
1007any show-stopping (or brown bag) bugs are found by testers of the
1008release candidate.
1009
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001010All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001011to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001012
1013Core language, builtins, and interpreter
1014
1015- A bug that caused crashes when __coerce__ was used with augmented
1016 assignment, e.g. +=, was fixed.
1017
1018- Raise ZeroDivisionError when raising zero to a negative number,
1019 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1020 power operator and the result of math.pow(0.0, -2.0) will vary by
1021 platform. On Linux, it raises a ValueError.
1022
1023- A bug in Unicode string interpolation was fixed that occasionally
1024 caused errors with formats including "%%". For example, the
1025 following expression "%% %s" % u"abc" no longer raises a TypeError.
1026
1027- Compilation of deeply nested expressions raises MemoryError instead
1028 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1029
1030- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1031 rendering them useless. They are now written in binary mode again.
1032
1033Standard library
1034
1035- Keyword arguments are now accepted for most pattern and match object
1036 methods in SRE, the standard regular expression engine.
1037
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001038- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001039 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001040
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001041- Several bugs in the Unicode handling and error handling in _tkinter
1042 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001043
1044- Fix memory management errors in Merge() and Tkapp_Call() routines.
1045
1046- Several changes were made to cStringIO to make it compatible with
1047 the file-like object interface and with StringIO. If operations are
1048 performed on a closed object, an exception is raised. The truncate
1049 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001050 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001051
1052- There were many changes made to the linuxaudiodev module and its
1053 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001054 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001055
1056 Note that this module is named poorly, because it should work
1057 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001058 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001059
1060 The module now raises exceptions when errors occur instead of
1061 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1062 audio) and defines a getptr() method that calls the
1063 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1064
1065- The library_version attribute, introduced in an earlier beta, was
1066 removed because it can not be supported with early versions of the C
1067 readline library, which provides no way to determine the version at
1068 compile-time.
1069
1070- The binascii module is now enabled on Win64.
1071
Tim Peters46446d62000-10-09 21:19:31 +00001072- tokenize.py no longer suffers "recursion depth" errors when parsing
1073 programs with very long string literals.
1074
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001075Internals
1076
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001077- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001078 which is called when the interpreter starts up to determine where
1079 the standard library is installed. These vulnerabilities affect all
1080 previous versions of Python and can be exploited by setting very
1081 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1082 setuid Python script, although use of the wrapper in
1083 Misc/setuid-prog.c will eliminate the vulnerability.
1084
1085- Fixed garbage collection bugs in instance creation that were
1086 triggered when errors occurred during initialization. The solution,
1087 applied in cPickle and in PyInstance_New(), is to call
1088 PyObject_GC_Init() after the initialization of the object's
1089 container attributes is complete.
1090
1091- pyexpat adds definitions of PyModule_AddStringConstant and
1092 PyModule_AddObject if the Python version is less than 2.0, which
1093 provides compatibility with PyXML on Python 1.5.2.
1094
1095- If the platform has a bogus definition for LONG_BIT (the number of
1096 bits in a long), an error will be reported at compile time.
1097
1098- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1099 collection crashes and possibly other, unreported crashes.
1100
1101- Fixed a memory leak in _PyUnicode_Fini().
1102
1103Build issues
1104
1105- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001106 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001107 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001108
1109- The mmap.PAGESIZE constant is now initialized using sysconf when
1110 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1111
1112- The md5 file should now compile on all platforms.
1113
1114- The select module now compiles on platforms that do not define
1115 POLLRDNORM and related constants.
1116
1117- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001118 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001119
Jeremy Hylton10921202000-10-09 18:34:12 +00001120- BeOS: A number of changes were made to the build and installation
1121 process. ar-fake now operates on a directory of object files.
1122 dl_export.h is gone, and its macros now appear on the mwcc command
1123 line during build on PPC BeOS.
1124
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001125- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001126 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001127
1128- Cygwin: Support for shared libraries, Tkinter, and sockets.
1129
1130- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1131
1132Tools and other miscellany
1133
1134- Removed debugging prints from main used with freeze.
1135
Tim Peters46446d62000-10-09 21:19:31 +00001136- IDLE auto-indent no longer crashes when it encounters Unicode
1137 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001138
1139What's new in 2.0 beta 2 (since beta 1)?
1140========================================
1141
1142Core language, builtins, and interpreter
1143
Tim Peters482c0212000-09-26 06:33:09 +00001144- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001145 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001146
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001147- Add -h and -V command line options to print the usage message and
1148 Python version number and exit immediately.
1149
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001150- eval() and exec accept Unicode objects as code parameters.
1151
1152- getattr() and setattr() now also accept Unicode objects for the
1153 attribute name, which are converted to strings using the default
1154 encoding before lookup.
1155
1156- Multiplication on string and Unicode now does proper bounds
1157 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1158 string is too long."
1159
1160- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001161 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001162
Jeremy Hylton1b618592000-09-26 05:32:36 +00001163
1164Standard library and extensions
1165
Guido van Rossum5b08f132001-04-16 02:05:23 +00001166- socket module: the OpenSSL code now adds support for RAND_status()
1167 and EGD (Entropy Gathering Device).
1168
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001169- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001170 argument checking; it still takes no arguments.
1171
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001172- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001173
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001174- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001175
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001176- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001177
1178- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001179 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001180
1181- copy: Copy Unicode objects atomically.
1182
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001183- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001184
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001185- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001186
Fred Drake67233bc2000-09-26 16:40:27 +00001187- dbm: Add get() and setdefault() methods to dbm object. Add constant
1188 `library' to module that names the library used. Added doc strings
1189 and method names to error messages. Uses configure to determine
1190 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1191 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001192
1193- distutils: Update to version 0.9.3.
1194
1195- dl: Add several dl.RTLD_ constants.
1196
1197- fpectl: Now supported on FreeBSD.
1198
1199- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1200 found by the collector will be saved in gc.garbage. This is useful
1201 for debugging a program that creates reference cycles.
1202
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001203- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001204 of HTTP class. Do not close socket on zero-length response. Do not
1205 crash when server sends invalid content-length header.
1206
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001207- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001208
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001209- marshal: When reading a short, sign-extend on platforms where shorts
1210 are bigger than 16 bits. When reading a long, repair the unportable
1211 sign extension that was being done for 64-bit machines. (It assumed
1212 that signed right shift sign-extends.)
1213
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001214- operator: Add contains(), invert(), __invert__() as aliases for
1215 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001216
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001217- os: Add support for popen2() and popen3() on all platforms where
1218 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001219
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001220- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001221 clicking on a file in Explorer (or passing the file name to the
1222 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001223
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001224- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001225 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001226
1227- pickle: Now raises ValueError when an invalid pickle that contains
1228 a non-string repr where a string repr was expected. This behavior
1229 matches cPickle.
1230
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001231- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001232
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001233- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001234
1235- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001236 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001237 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001238
1239- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001240 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001241
1242- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001243 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001244 few cycles during startup since the first call to
1245 setdefaultencoding() will initialize the codec registry and the
1246 encodings package.
1247
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001248- socket: Support for size hint in readlines() method of object returned
1249 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001250
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001251- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001252 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001253 is followed by whitespace.
1254
Tim Petersa3a3a032000-11-30 05:22:44 +00001255- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001256
1257- struct: Check ranges for bytes and shorts.
1258
1259- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001260 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001261
1262- Tkinter: Image objects are now guaranteed to have unique ids. Set
1263 event.delta to zero if Tk version doesn't support mousewheel.
1264 Removed some debugging prints.
1265
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001266- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001267
Fred Drake67233bc2000-09-26 16:40:27 +00001268- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001269 which works around a bug in Norton AntiVirus 2000 that leads directly
1270 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001271
1272- xml: New version detection code allows PyXML to override standard
1273 XML package if PyXML version is greater than 0.6.1.
1274
Fred Drake64bb3802000-09-26 16:21:35 +00001275- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1276 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1277 tree only for nodes which are sufficiently interesting to a specific
1278 application. Does not provide the HTML-specific extensions. Still
1279 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001280
Fred Drake64bb3802000-09-26 16:21:35 +00001281- xml.sax: SAX 2 support for Python, including all the handler
1282 interfaces needed to process XML 1.0 compliant XML. Some
1283 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001284
Fred Drake64bb3802000-09-26 16:21:35 +00001285- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1286 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001287
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001288
Jeremy Hylton1b618592000-09-26 05:32:36 +00001289C API
1290
1291- Add three new convenience functions for module initialization --
1292 PyModule_AddObject(), PyModule_AddIntConstant(), and
1293 PyModule_AddStringConstant().
1294
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001295- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001296 removed and add #error to Python.h if NULL isn't defined after
1297 #include of stdio.h.
1298
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001299- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001300 backwards compatibility (at the source level) with old extensions.
1301
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001302- A wrapper API was added for signal() and sigaction(). Instead of
1303 either function, always use PyOS_getsig() to get a signal handler
1304 and PyOS_setsig() to set one. A new convenience typedef
1305 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001306
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001307- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001308 internal data buffer and size of a string object -- or the default
1309 encoded version of a Unicode object.
1310
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001311- PyString_Size() and PyString_AsString() accept Unicode objects.
1312
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001313- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001314 exists). INT_MAX and LONG_MAX will always be defined, even if
1315 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001316
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001317- PyFloat_FromString takes a second argument, pend, that was
1318 effectively useless. It is now officially useless but preserved for
1319 backwards compatibility. If the pend argument is not NULL, *pend is
1320 set to NULL.
1321
1322- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1323 for the attribute name. See note on getattr() above.
1324
1325- A few bug fixes to argument processing for Unicode.
1326 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1327 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1328 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001329 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001330
1331- Py_BuildValue accepts B format (for bgen-generated code).
1332
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001333
Jeremy Hylton1b618592000-09-26 05:32:36 +00001334Internals
1335
1336- On Unix, fix code for finding Python installation directory so that
1337 it works when argv[0] is a relative path.
1338
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001339- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001340 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001341 rather than by generating a copy of the object.
1342
Tim Peters482c0212000-09-26 06:33:09 +00001343- Several of the internal Unicode tables are much smaller now, and
1344 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001345
Jeremy Hylton97693b02000-09-26 17:42:51 +00001346- In the garbage collector: Fixed bug in collection of tuples. Fixed
1347 bug that caused some instances to be removed from the container set
1348 while they were still live. Fixed parsing in gc.set_debug() for
1349 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001350
1351- Fixed refcount problem in instance deallocation that only occurred
1352 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1353
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001354- On Windows, getpythonregpath is now protected against null data in
1355 registry key.
1356
1357- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001358 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001359
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001360
Jeremy Hylton1b618592000-09-26 05:32:36 +00001361Build and platform-specific issues
1362
1363- Better support of GNU Pth via --with-pth configure option.
1364
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001365- Python/C API now properly exposed to dynamically-loaded extension
1366 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001367
1368- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1369 Don't define MS_SYNC to be zero when it is undefined. Added missing
1370 prototypes in posixmodule.c.
1371
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001372- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001373 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001374
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001375- Fix largefile support on older NetBSD systems and OpenBSD by adding
1376 define for TELL64.
1377
1378
1379Tools and other miscellany
1380
1381- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1382
1383- freeze: The modulefinder now works with 2.0 opcodes.
1384
Tim Petersa3a3a032000-11-30 05:22:44 +00001385- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001386 Move hackery of sys.argv until after the Tk instance has been
1387 created, which allows the application-specific Tkinter
1388 initialization to be executed if present; also pass an explicit
1389 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001390
Jeremy Hylton1b618592000-09-26 05:32:36 +00001391
1392What's new in 2.0 beta 1?
1393=========================
1394
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001395Source Incompatibilities
1396------------------------
1397
1398None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1399such as single-argument append(), connect() and bind(), and changes to
1400str(long) and repr(float).
1401
1402
1403Binary Incompatibilities
1404------------------------
1405
1406- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1407with Python 2.0; these extensions will have to be rebuilt for Python
14082.0.
1409
1410- On Windows, attempting to import a third party extension built for
1411Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1412can do about this. Check your PYTHONPATH environment variable!
1413
1414- Python bytecode files (*.pyc and *.pyo) are not compatible between
1415releases.
1416
1417
1418Overview of Changes Since 1.6
1419-----------------------------
1420
1421There are many new modules (including brand new XML support through
1422the xml package, and i18n support through the gettext module); a list
1423of all new modules is included below. Lots of bugs have been fixed.
1424
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001425The process for making major new changes to the language has changed
1426since Python 1.6. Enhancements must now be documented by a Python
1427Enhancement Proposal (PEP) before they can be accepted.
1428
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001429There are several important syntax enhancements, described in more
1430detail below:
1431
1432 - Augmented assignment, e.g. x += 1
1433
1434 - List comprehensions, e.g. [x**2 for x in range(10)]
1435
1436 - Extended import statement, e.g. import Module as Name
1437
1438 - Extended print statement, e.g. print >> file, "Hello"
1439
1440Other important changes:
1441
1442 - Optional collection of cyclical garbage
1443
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001444Python Enhancement Proposal (PEP)
1445---------------------------------
1446
1447PEP stands for Python Enhancement Proposal. A PEP is a design
1448document providing information to the Python community, or describing
1449a new feature for Python. The PEP should provide a concise technical
1450specification of the feature and a rationale for the feature.
1451
1452We intend PEPs to be the primary mechanisms for proposing new
1453features, for collecting community input on an issue, and for
1454documenting the design decisions that have gone into Python. The PEP
1455author is responsible for building consensus within the community and
1456documenting dissenting opinions.
1457
1458The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001459
1460Augmented Assignment
1461--------------------
1462
1463This must have been the most-requested feature of the past years!
1464Eleven new assignment operators were added:
1465
Guido van Rossume905e952000-09-05 12:42:46 +00001466 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001467
1468For example,
1469
1470 A += B
1471
1472is similar to
1473
1474 A = A + B
1475
1476except that A is evaluated only once (relevant when A is something
1477like dict[index].attr).
1478
1479However, if A is a mutable object, A may be modified in place. Thus,
1480if A is a number or a string, A += B has the same effect as A = A+B
1481(except A is only evaluated once); but if a is a list, A += B has the
1482same effect as A.extend(B)!
1483
1484Classes and built-in object types can override the new operators in
1485order to implement the in-place behavior; the not-in-place behavior is
1486used automatically as a fallback when an object doesn't implement the
1487in-place behavior. For classes, the method name is derived from the
1488method name for the corresponding not-in-place operator by inserting
1489an 'i' in front of the name, e.g. __iadd__ implements in-place
1490__add__.
1491
1492Augmented assignment was implemented by Thomas Wouters.
1493
1494
1495List Comprehensions
1496-------------------
1497
1498This is a flexible new notation for lists whose elements are computed
1499from another list (or lists). The simplest form is:
1500
1501 [<expression> for <variable> in <sequence>]
1502
Guido van Rossum56db0952000-09-06 23:34:25 +00001503For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001504This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001505
1506You can also add a condition:
1507
1508 [<expression> for <variable> in <sequence> if <condition>]
1509
1510For example, [w for w in words if w == w.lower()] would yield the list
1511of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001512than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001513
1514You can also have nested for loops and more than one 'if' clause. For
1515example, here's a function that flattens a sequence of sequences::
1516
1517 def flatten(seq):
1518 return [x for subseq in seq for x in subseq]
1519
1520 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1521
1522This prints
1523
1524 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1525
1526List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001527Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001528
1529
1530Extended Import Statement
1531-------------------------
1532
1533Many people have asked for a way to import a module under a different
1534name. This can be accomplished like this:
1535
1536 import foo
1537 bar = foo
1538 del foo
1539
1540but this common idiom gets old quickly. A simple extension of the
1541import statement now allows this to be written as follows:
1542
1543 import foo as bar
1544
1545There's also a variant for 'from ... import':
1546
1547 from foo import bar as spam
1548
1549This also works with packages; e.g. you can write this:
1550
1551 import test.regrtest as regrtest
1552
1553Note that 'as' is not a new keyword -- it is recognized only in this
1554context (this is only possible because the syntax for the import
1555statement doesn't involve expressions).
1556
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001557Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001558
1559
1560Extended Print Statement
1561------------------------
1562
1563Easily the most controversial new feature, this extension to the print
1564statement adds an option to make the output go to a different file
1565than the default sys.stdout.
1566
1567For example, to write an error message to sys.stderr, you can now
1568write:
1569
1570 print >> sys.stderr, "Error: bad dog!"
1571
1572As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001573evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001574
1575 print >> None, "Hello world"
1576
1577is equivalent to
1578
1579 print "Hello world"
1580
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001581Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001582
1583
1584Optional Collection of Cyclical Garbage
1585---------------------------------------
1586
1587Python is now equipped with a garbage collector that can hunt down
1588cyclical references between Python objects. It's no replacement for
1589reference counting; in fact, it depends on the reference counts being
1590correct, and decides that a set of objects belong to a cycle if all
1591their reference counts can be accounted for from their references to
1592each other. This devious scheme was first proposed by Eric Tiedemann,
1593and brought to implementation by Neil Schemenauer.
1594
1595There's a module "gc" that lets you control some parameters of the
1596garbage collection. There's also an option to the configure script
1597that lets you enable or disable the garbage collection. In 2.0b1,
1598it's on by default, so that we (hopefully) can collect decent user
1599experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001600performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001601off by default in the final 2.0 release.
1602
1603
1604Smaller Changes
1605---------------
1606
1607A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1608map(None, seq1, seq2, ...) when the sequences have the same length;
1609i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1610the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001611zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001612
1613sys.version_info is a tuple (major, minor, micro, level, serial).
1614
1615Dictionaries have an odd new method, setdefault(key, default).
1616dict.setdefault(key, default) returns dict[key] if it exists; if not,
1617it sets dict[key] to default and returns that value. Thus:
1618
1619 dict.setdefault(key, []).append(item)
1620
1621does the same work as this common idiom:
1622
1623 if not dict.has_key(key):
1624 dict[key] = []
1625 dict[key].append(item)
1626
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001627There are two new variants of SyntaxError that are raised for
1628indentation-related errors: IndentationError and TabError.
1629
1630Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1631escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001632
1633The limits on the size of expressions and file in Python source code
1634have been raised from 2**16 to 2**32. Previous versions of Python
1635were limited because the maximum argument size the Python VM accepted
1636was 2**16. This limited the size of object constructor expressions,
1637e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1638limit was raised thanks to a patch by Charles Waldman that effectively
1639fixes the problem. It is now much more likely that you will be
1640limited by available memory than by an arbitrary limit in Python.
1641
1642The interpreter's maximum recursion depth can be modified by Python
1643programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1644limit is the maximum number of recursive calls that can be made by
1645Python code. The limit exists to prevent infinite recursion from
1646overflowing the C stack and causing a core dump. The default value is
16471000. The maximum safe value for a particular platform can be found
1648by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001649
1650New Modules and Packages
1651------------------------
1652
1653atexit - for registering functions to be called when Python exits.
1654
1655imputil - Greg Stein's alternative API for writing custom import
1656hooks.
1657
1658pyexpat - an interface to the Expat XML parser, contributed by Paul
1659Prescod.
1660
1661xml - a new package with XML support code organized (so far) in three
1662subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1663would fill a volume. There's a special feature whereby a
1664user-installed package named _xmlplus overrides the standard
1665xmlpackage; this is intended to give the XML SIG a hook to distribute
1666backwards-compatible updates to the standard xml package.
1667
1668webbrowser - a platform-independent API to launch a web browser.
1669
1670
Guido van Rossume905e952000-09-05 12:42:46 +00001671Changed Modules
1672---------------
1673
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001674array -- new methods for array objects: count, extend, index, pop, and
1675remove
1676
1677binascii -- new functions b2a_hex and a2b_hex that convert between
1678binary data and its hex representation
1679
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001680calendar -- Many new functions that support features including control
1681over which day of the week is the first day, returning strings instead
1682of printing them. Also new symbolic constants for days of week,
1683e.g. MONDAY, ..., SUNDAY.
1684
1685cgi -- FieldStorage objects have a getvalue method that works like a
1686dictionary's get method and returns the value attribute of the object.
1687
1688ConfigParser -- The parser object has new methods has_option,
1689remove_section, remove_option, set, and write. They allow the module
1690to be used for writing config files as well as reading them.
1691
1692ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001693optionally support the RFC 959 REST command.
1694
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001695gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001696
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001697httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1698the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001699
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001700locale -- implement getdefaultlocale for Win32 and Macintosh
1701
1702marshal -- no longer dumps core when marshaling deeply nested or
1703recursive data structures
1704
1705os -- new functions isatty, seteuid, setegid, setreuid, setregid
1706
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001707os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1708support under Unix.
1709
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001710os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001711
1712os.path -- fix semantics of os.path.commonprefix
1713
1714smtplib -- support for sending very long messages
1715
1716socket -- new function getfqdn()
1717
1718readline -- new functions to read, write and truncate history files.
1719The readline section of the library reference manual contains an
1720example.
1721
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001722select -- add interface to poll system call
1723
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001724shutil -- new copyfileobj function
1725
1726SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1727HTTP server.
1728
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001729Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001730
1731urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001732e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001733
1734whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001735
1736
1737Obsolete Modules
1738----------------
1739
1740None. However note that 1.6 made a whole slew of modules obsolete:
1741stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1742poly, zmod, strop, util, whatsound.
1743
1744
1745Changed, New, Obsolete Tools
1746----------------------------
1747
Tim Peters8b092332000-09-05 20:15:25 +00001748None.
Guido van Rossume905e952000-09-05 12:42:46 +00001749
1750
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001751C-level Changes
1752---------------
1753
1754Several cleanup jobs were carried out throughout the source code.
1755
1756All C code was converted to ANSI C; we got rid of all uses of the
1757Py_PROTO() macro, which makes the header files a lot more readable.
1758
1759Most of the portability hacks were moved to a new header file,
1760pyport.h; several other new header files were added and some old
1761header files were removed, in an attempt to create a more rational set
1762of header files. (Few of these ever need to be included explicitly;
1763they are all included by Python.h.)
1764
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001765Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001766and Win64, especially for the new Intel Itanium processor. Mick also
1767added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001768
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001769The C APIs to return an object's size have been update to consistently
1770use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1771previous versions, the abstract interfaces used PyXXX_Length and the
1772concrete interfaces used PyXXX_Size. The old names,
1773e.g. PyObject_Length, are still available for backwards compatibility
1774at the API level, but are deprecated.
1775
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001776The PyOS_CheckStack function has been implemented on Windows by
1777Fredrik Lundh. It prevents Python from failing with a stack overflow
1778on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001779
1780The GC changes resulted in creation of two new slots on object,
1781tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001782the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001783
1784The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001785C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001786
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001787PyErr_Format has been updated to automatically calculate the size of
1788the buffer needed to hold the formatted result string. This change
1789prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001790
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001791New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001792
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001793PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1794that are the same as their non-Ex counterparts except they take an
1795extra flag argument that tells them to close the file when done.
1796
1797XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001798
Tim Peters8b092332000-09-05 20:15:25 +00001799
1800Windows Changes
1801---------------
1802
1803New popen2/popen3/peopen4 in os module (see Changed Modules above).
1804
1805os.popen is much more usable on Windows 95 and 98. See Microsoft
1806Knowledge Base article Q150956. The Win9x workaround described there
1807is implemented by the new w9xpopen.exe helper in the root of your
1808Python installation. Note that Python uses this internally; it is not
1809a standalone program.
1810
1811Administrator privileges are no longer required to install Python
1812on Windows NT or Windows 2000. If you have administrator privileges,
1813Python's registry info will be written under HKEY_LOCAL_MACHINE.
1814Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001815under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001816uses of Python, but will prevent some advanced uses from working
1817(for example, running a Python script as an NT service, or possibly
1818from CGI).
1819
1820[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1821installer; instead, it installs the needed Tcl/Tk files directly in the
1822Python directory. If you already have a Tcl/Tk installation, this
1823wastes some disk space (about 4 Megs) but avoids problems with
1824conflicting Tcl/Tk installations, and makes it much easier for Python
1825to ensure that Tcl/Tk can find all its files.
1826
1827[This was new in 1.6] The Windows installer now installs by default in
1828\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1829
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001830
1831Updates to the changes between 1.5.2 and 1.6
1832--------------------------------------------
1833
1834The 1.6 NEWS file can't be changed after the release is done, so here
1835is some late-breaking news:
1836
1837New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1838and changes to getlocale() and setlocale().
1839
1840The new module is now enabled per default.
1841
1842It is not true that the encodings codecs cannot be used for normal
1843strings: the string.encode() (which is also present on 8-bit strings
1844!) allows using them for 8-bit strings too, e.g. to convert files from
1845cp1252 (Windows) to latin-1 or vice-versa.
1846
1847Japanese codecs are available from Tamito KAJIYAMA:
1848http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1849
1850
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001851======================================================================