blob: 8b4021f85d5d60e450676ca1be075d9b1251074e [file] [log] [blame]
Tim Petersf553f892001-05-01 20:45:31 +00001What's New in Python 2.2a0?
2===========================
3
4Core
5
Tim Peters61dff2b2001-05-08 15:43:37 +00006- Float (and complex) literals in source code were evaluated to full
7 precision only when running from a .py file; the same code loaded from a
8 .pyc (or .pyo) file could suffer numeric differences starting at about the
9 12th significant decimal digit. For example, on a machine with IEEE-754
10 floating arithmetic,
11
12 x = 9007199254740992.0
13 print long(x)
14
15 printed 9007199254740992 if run directly from .py, but 9007199254740000
16 if from a compiled (.pyc or .pyo) file. This was due to marshal using
17 str(float) instead of repr(float) when building code objects. marshal
18 now uses repr(float) instead, which should reproduce floats to full
19 machine precision (assuming the platform C float<->string I/O conversion
20 functions are of good quality).
21
22 This may cause floating-point results to change in some cases, and
23 usually for the better, but may also cause numerically unstable
24 algorithms to break.
25
Guido van Rossum10315822001-05-01 20:54:30 +000026- Dictionary objects now support the "in" operator: "x in dict" means
27 the same as dict.has_key(x).
28
29- Iterators were added; this is a generalized way of providing values
30 to a for loop. See PEP 234. There's a new built-in function iter()
31 to return an iterator. There's a new protocol to get the next value
32 from an iterator using the next() method (in Python) or the
33 tp_iternext slot (in C). There's a new protocol to get iterators
34 using the __iter__() method (in Python) or the tp_iter slot (in C).
35 Iterating (i.e. a for loop) over a dictionary generates its keys.
36 Iterating over a file generates its lines.
37
Tim Petersf553f892001-05-01 20:45:31 +000038- The following functions were generalized to work nicely with iterator
39 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +000040 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +000041 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
42 max(), min()
Tim Petersde9725f2001-05-05 10:06:17 +000043 .join() method of strings
Tim Peters75f8e352001-05-05 11:33:43 +000044 'x in y' and 'x not in y' (PySequence_Contains() in C API)
45 operator.countOf() (PySequence_Count() in C API)
Tim Peters75f8e352001-05-05 11:33:43 +000046
Tim Peterse63415e2001-05-08 04:38:29 +000047- Comparing dictionary objects via == and != is faster, and now works even
48 if the keys and values don't support comparisons other than ==.
49
Tim Peters95bf9392001-05-10 08:32:44 +000050- Comparing dictionaries in ways other than == and != is slower: there were
51 insecurities in the dict comparison implementation that could cause Python
52 to crash if the element comparison routines for the dict keys and/or
53 values mutated the dicts. Making the code bulletproof slowed it down.
54
Tim Petersf553f892001-05-01 20:45:31 +000055
Guido van Rossumffe13be2001-04-16 18:46:45 +000056What's New in Python 2.1 (final)?
57=================================
58
59We only changed a few things since the last release candidate, all in
60Python library code:
61
62- A bug in the locale module was fixed that affected locales which
63 define no grouping for numeric formatting.
64
65- A few bugs in the weakref module's implementations of weak
66 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
67 and the test suite was updated to check for these bugs.
68
69- An old bug in the os.path.walk() function (introduced in Python
70 2.0!) was fixed: a non-existent file would cause an exception
71 instead of being ignored.
72
73- Fixed a few bugs in the new symtable module found by Neil Norwitz's
74 PyChecker.
75
76
Guido van Rossum5b08f132001-04-16 02:05:23 +000077What's New in Python 2.1c2?
78===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +000079
Guido van Rossum5b08f132001-04-16 02:05:23 +000080A flurry of small changes, and one showstopper fixed in the nick of
81time made it necessary to release another release candidate. The list
82here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +000083
Guido van Rossum5b08f132001-04-16 02:05:23 +000084Core
Guido van Rossum4fb60362001-04-13 00:46:14 +000085
Guido van Rossum5b08f132001-04-16 02:05:23 +000086- Tim discovered a nasty bug in the dictionary code, caused by
87 PyDict_Next() calling dict_resize(), and the GC code's use of
88 PyDict_Next() violating an assumption in dict_items(). This was
89 fixed with considerable amounts of band-aid, but the net effect is a
90 saner and more robust implementation.
91
92- Made a bunch of symbols static that were accidentally global.
93
94Build and Ports
95
96- The setup.py script didn't check for a new enough version of zlib
97 (1.1.3 is needed). Now it does.
98
99- Changed "make clean" target to also remove shared libraries.
100
101- Added a more general warning about the SGI Irix optimizer to README.
102
103Library
104
105- Fix a bug in urllib.basejoin("http://host", "../file.html") which
106 omitted the slash between host and file.html.
107
108- The mailbox module's _Mailbox class contained a completely broken
109 and undocumented seek() method. Ripped it out.
110
111- Fixed a bunch of typos in various library modules (urllib2, smtpd,
112 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
113
114- Fixed a few last-minute bugs in unittest.
115
116Extensions
117
118- Reverted the patch to the OpenSSL code in socketmodule.c to support
119 RAND_status() and the EGD, and the subsequent patch that tried to
120 fix it for pre-0.9.5 versions; the problem with the patch is that on
121 some systems it issues a warning whenever socket is imported, and
122 that's unacceptable.
123
124Tests
125
126- Fixed the pickle tests to work with "import test.test_pickle".
127
128- Tweaked test_locale.py to actually run the test Windows.
129
130- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
131 not "wb" (which is not a valid mode at all).
132
133- Fix pstats browser crashes. Import readline if it exists to make
134 the user interface nicer.
135
136- Add "import thread" to the top of test modules that import the
137 threading module (test_asynchat and test_threadedtempfile). This
138 prevents test failures caused by a broken threading module resulting
139 from a previously caught failed import.
140
141- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
142 needed on some platforms (e.g. Solaris 8) when the tests are run
143 twice in succession.
144
145- Skip rather than fail test_sunaudiodev if no audio device is found.
146
147
148What's New in Python 2.1c1?
149===========================
150
151This list was significantly updated when 2.1c2 was released; the 2.1c1
152release didn't mention most changes that were actually part of 2.1c1:
153
154Legal
155
156- Copyright was assigned to the Python Software Foundation (PSF) and a
157 PSF license (very similar to the CNRI license) was added.
158
159- The CNRI copyright notice was updated to include 2001.
160
161Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000162
Guido van Rossumc9932722001-04-12 02:31:27 +0000163- After a public outcry, assignment to __debug__ is no longer illegal;
164 instead, a warning is issued. It will become illegal in 2.2.
165
Guido van Rossum5b08f132001-04-16 02:05:23 +0000166- Fixed a core dump with "%#x" % 0, and changed the semantics so that
167 "%#x" now always prepends "0x", even if the value is zero.
168
169- Fixed some nits in the bytecode compiler.
170
171- Fixed core dumps when calling certain kinds of non-functions.
172
173- Fixed various core dumps caused by reference count bugs.
174
175Build and Ports
176
177- Use INSTALL_SCRIPT to install script files.
178
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000179- New port: SCO Unixware 7, by Billy G. Allie.
180
Guido van Rossum5b08f132001-04-16 02:05:23 +0000181- Updated RISCOS port.
182
183- Updated BeOS port and notes.
184
185- Various other porting problems resolved.
186
187Library
188
189- The TERMIOS and SOCKET modules are now truly obsolete and
190 unnecessary. Their symbols are incorporated in the termios and
191 socket modules.
192
193- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
194 better tests for pickling.
195
196- threading: make Condition.wait() robust against KeyboardInterrupt.
197
198- zipfile: add support to zipfile to support opening an archive
199 represented by an open file rather than a file name. Fix bug where
200 the archive was not properly closed. Fixed a bug in this bugfix
201 where flush() was called for a read-only file.
202
203- imputil: added an uninstall() method to the ImportManager.
204
205- Canvas: fixed bugs in lower() and tkraise() methods.
206
207- SocketServer: API change (added overridable close_request() method)
208 so that the TCP server can explicitly close the request.
209
210- pstats: Eric Raymond added a simple interactive statistics browser,
211 invoked when the module is run as a script.
212
213- locale: fixed a problem in format().
214
215- webbrowser: made it work when the BROWSER environment variable has a
216 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
217 KDE 2. Fixed some other nits.
218
219- unittest: changes to allow using a different exception than
220 AssertionError, and added a few more function aliases. Some other
221 small changes.
222
223- urllib, urllib2: fixed redirect problems and a coupleof other nits.
224
225- asynchat: fixed a critical bug in asynchat that slipped through the
226 2.1b2 release. Fixed another rare bug.
227
228- Fix some unqualified except: clauses (always a bad code example).
229
230XML
231
232- pyexpat: new API get_version_string().
233
234- Fixed some minidom bugs.
235
236Extensions
237
238- Fixed a core dump in _weakref. Removed the weakref.mapping()
239 function (it adds nothing to the API).
240
241- Rationalized the use of header files in the readline module, to make
242 it compile (albeit with some warnings) with the very recent readline
243 4.2, without breaking for earlier versions.
244
245- Hopefully fixed a buffering problem in linuxaudiodev.
246
247- Attempted a fix to make the OpenSSL support in the socket module
248 work again with pre-0.9.5 versions of OpenSSL.
249
250Tests
251
252- Added a test case for asynchat and asyncore.
253
254- Removed coupling between tests where one test failing could break
255 another.
256
257Tools
258
259- Ping added an interactive help browser to pydoc, fixed some nits
260 in the rest of the pydoc code, and added some features to his
261 inspect module.
262
263- An updated python-mode.el version 4.1 which integrates Ken
264 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
265 much nicer in XEmacs and Emacs. When stepping through your program
266 with pdb, in either the shell window or the *Python* window, the
267 source file and line will be tracked by an arrow. Very cool!
268
269- IDLE: syntax warnings in interactive mode are changed into errors.
270
271- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000272 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000273
274- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000275
Barry Warsaw11e89c72001-04-11 20:37:57 +0000276
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000277What's New in Python 2.1 beta 2?
278================================
279
Guido van Rossum053ae352001-03-22 14:17:21 +0000280(Unlisted are many fixed bugs, more documentation, etc.)
281
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000282Core language, builtins, and interpreter
283
Guido van Rossum053ae352001-03-22 14:17:21 +0000284- The nested scopes work (enabled by "from __future__ import
285 nested_scopes") is completed; in particular, the future now extends
286 into code executed through exec, eval() and execfile(), and into the
287 interactive interpreter.
288
289- When calling a base class method (e.g. BaseClass.__init__(self)),
290 this is now allowed even if self is not strictly spoken a class
291 instance (e.g. when using metaclasses or the Don Beaudry hook).
292
293- Slice objects are now comparable but not hashable; this prevents
294 dict[:] from being accepted but meaningless.
295
296- Complex division is now calculated using less braindead algorithms.
297 This doesn't change semantics except it's more likely to give useful
298 results in extreme cases. Complex repr() now uses full precision
299 like float repr().
300
301- sgmllib.py now calls handle_decl() for simple <!...> declarations.
302
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000303- It is illegal to assign to the name __debug__, which is set when the
304 interpreter starts. It is effectively a compile-time constant.
305
306- A warning will be issued if a global statement for a variable
307 follows a use or assignment of that variable.
308
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000309Standard library
310
Guido van Rossum053ae352001-03-22 14:17:21 +0000311- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
312 inspired by JUnit), is now part of the standard library. You now
313 have a choice of two testing frameworks: unittest requires you to
314 write testcases as separate code, doctest gathers them from
315 docstrings. Both approaches have their advantages and
316 disadvantages.
317
318- A new module Tix was added, which wraps the Tix extension library
319 for Tk. With that module, it is not necessary to statically link
320 Tix with _tkinter, since Tix will be loaded with Tcl's "package
321 require" command. See Demo/tix/.
322
323- tzparse.py is now obsolete.
324
325- In gzip.py, the seek() and tell() methods are removed -- they were
326 non-functional anyway, and it's better if callers can test for their
327 existence with hasattr().
328
329Python/C API
330
331- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
332 that's already in the dictionary during a PyDict_Next() iteration.
333 This used to fail occasionally when a dictionary resize operation
334 could be triggered that would rehash all the keys. All other
335 modifications to the dictionary are still off-limits during a
336 PyDict_Next() iteration!
337
338- New extended APIs related to passing compiler variables around.
339
340- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
341 implement isinstance() and issubclass().
342
343- Py_BuildValue() now has a "D" conversion to create a Python complex
344 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000345
Fred Drake4e262a92001-03-22 18:26:47 +0000346- Extensions types which support weak references must now set the
347 field allocated for the weak reference machinery to NULL themselves;
348 this is done to avoid the cost of checking each object for having a
349 weakly referencable type in PyObject_INIT(), since most types are
350 not weakly referencable.
351
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000352- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
353 free variables and cell variables to and from the frame's f_locals.
354
355- Variants of several functions defined in pythonrun.h have been added
356 to support the nested_scopes future statement. The variants all end
357 in Flags and take an extra argument, a PyCompilerFlags *; examples:
358 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
359 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000360 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000361
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000362Distutils
363
364- the sdist command now writes a PKG-INFO file, as described in PEP 241,
365 into the release tree.
366
Tim Peters0e57abf2001-05-02 07:39:38 +0000367- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000368 (an uninstaller, more customization of the installer's display)
369
370- from Jack Jansen: added Mac-specific code to generate a dialog for
371 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000372 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000373 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000374
375- added 'platforms' and 'keywords' to the set of metadata that can be
376 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000377
378- applied patches from Jason Tishler to make the compiler class work with
379 Cygwin.
380
381
Tim Peters2fe289a2001-03-01 22:19:38 +0000382What's New in Python 2.1 beta 1?
383================================
Tim Petersd66595f2001-02-04 03:09:53 +0000384
385Core language, builtins, and interpreter
386
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000387- Following an outcry from the community about the amount of code
388 broken by the nested scopes feature introduced in 2.1a2, we decided
389 to make this feature optional, and to wait until Python 2.2 (or at
390 least 6 months) to make it standard. The option can be enabled on a
391 per-module basis by adding "from __future__ import nested_scopes" at
392 the beginning of a module (before any other statements, but after
393 comments and an optional docstring). See PEP 236 (Back to the
394 __future__) for a description of the __future__ statement. PEP 227
395 (Statically Nested Scopes) has been updated to reflect this change,
396 and to clarify the semantics in a number of endcases.
397
398- The nested scopes code, when enabled, has been hardened, and most
399 bugs and memory leaks in it have been fixed.
400
401- Compile-time warnings are now generated for a number of conditions
402 that will break or change in meaning when nested scopes are enabled:
403
404 - Using "from...import *" or "exec" without in-clause in a function
405 scope that also defines a lambda or nested function with one or
406 more free (non-local) variables. The presence of the import* or
407 bare exec makes it impossible for the compiler to determine the
408 exact set of local variables in the outer scope, which makes it
409 impossible to determine the bindings for free variables in the
410 inner scope. To avoid the warning about import *, change it into
411 an import of explicitly name object, or move the import* statement
412 to the global scope; to avoid the warning about bare exec, use
413 exec...in... (a good idea anyway -- there's a possibility that
414 bare exec will be deprecated in the future).
415
416 - Use of a global variable in a nested scope with the same name as a
417 local variable in a surrounding scope. This will change in
418 meaning with nested scopes: the name in the inner scope will
419 reference the variable in the outer scope rather than the global
420 of the same name. To avoid the warning, either rename the outer
421 variable, or use a global statement in the inner function.
422
Neil Schemenauera35c6882001-02-27 04:45:05 +0000423- An optional object allocator has been included. This allocator is
424 optimized for Python objects and should be faster and use less memory
425 than the standard system allocator. It is not enabled by default
426 because of possible thread safety problems. The allocator is only
427 protected by the Python interpreter lock and it is possible that some
428 extension modules require a thread safe allocator. The object
429 allocator can be enabled by providing the "--with-pymalloc" option to
430 configure.
431
Tim Petersd66595f2001-02-04 03:09:53 +0000432Standard library
433
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000434- pyexpat now detects the expat version if expat.h defines it. A
435 number of additional handlers are provided, which are only available
436 since expat 1.95. In addition, the methods SetParamEntityParsing and
437 GetInputContext of Parser objects are available with 1.95.x
438 only. Parser objects now provide the ordered_attributes and
439 specified_attributes attributes. A new module expat.model was added,
440 which offers a number of additional constants if 1.95.x is used.
441
442- xml.dom offers the new functions registerDOMImplementation and
443 getDOMImplementation.
444
445- xml.dom.minidom offers a toprettyxml method. A number of DOM
446 conformance issues have been resolved. In particular, Element now
447 has an hasAttributes method, and the handling of namespaces was
448 improved.
449
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000450- Ka-Ping Yee contributed two new modules: inspect.py, a module for
451 getting information about live Python code, and pydoc.py, a module
452 for interactively converting docstrings to HTML or text.
453 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000454 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000455 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
456 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000457
Tim Peters1eff7962001-03-01 02:31:33 +0000458- New library module difflib.py, primarily packaging the SequenceMatcher
459 class at the heart of the popular ndiff.py file-comparison tool.
460
461- doctest.py (a framework for verifying Python code examples in docstrings)
462 is now part of the std library.
463
Tim Petersd66595f2001-02-04 03:09:53 +0000464Windows changes
465
Guido van Rossume3955a82001-03-02 14:05:59 +0000466- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
467 small GUI that lets you browse the module docstrings using your
468 default web browser.
469
Tim Peters1eff7962001-03-01 02:31:33 +0000470- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
471 Platforms) is implemented. See
472
473 http://python.sourceforge.net/peps/pep-0235.html
474
475 for full details, especially the "Current Lower-Left Semantics" section.
476 The new Windows import rules are simpler than before:
477
478 A. If the PYTHONCASEOK environment variable exists, same as
479 before: silently accept the first case-insensitive match of any
480 kind; raise ImportError if none found.
481
482 B. Else search sys.path for the first case-sensitive match; raise
483 ImportError if none found.
484
485 The same rules have been implented on other platforms with case-
486 insensitive but case-preserving filesystems too (including Cygwin, and
487 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000488
Tim Peters25a9ce32001-02-19 07:06:36 +0000489- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
490 what it's supposed to do (and does do under NT and 2000) via direct
491 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000492 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000493 all Win9x systems before.
494
Tim Peters1eff7962001-03-01 02:31:33 +0000495- Build: Subproject _test (effectively) renamed to _testcapi.
496
Tim Peters2fe289a2001-03-01 22:19:38 +0000497New platforms
498
499- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
500 Thanks to Steven Majewski!
501
502- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
503 Tishler!
504
Guido van Rossum9089b272001-03-02 06:49:50 +0000505- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
506 Schwertberger! See RISCOS/README for more information -- it seems
507 that because of the bizarre filename conventions on RISCOS, no port
508 to that platform is easy. Note that the new variable os.endsep is
509 silently supported in order to make life easier on this platform,
510 but we don't advertise it because it's not worth for most folks to
511 care about RISCOS portability.
512
Tim Peters25a9ce32001-02-19 07:06:36 +0000513
Tim Petersd7b5e882001-01-25 03:36:26 +0000514What's New in Python 2.1 alpha 2?
515=================================
Tim Peters40ead762001-01-27 05:35:26 +0000516
Tim Petersd7b5e882001-01-25 03:36:26 +0000517Core language, builtins, and interpreter
518
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000519- Scopes nest. If a name is used in a function or class, but is not
520 local, the definition in the nearest enclosing function scope will
521 be used. One consequence of this change is that lambda statements
522 could reference variables in the namespaces where the lambda is
523 defined. In some unusual cases, this change will break code.
524
525 In all previous version of Python, names were resolved in exactly
526 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000527 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000528 function A is defined within a function B, the names bound in B are
529 not visible in A. The new rules make names bound in B visible in A,
530 unless A contains a name binding that hides the binding in B.
531
532 Section 4.1 of the reference manual describes the new scoping rules
533 in detail. The test script in Lib/test/test_scope.py demonstrates
534 some of the effects of the change.
535
536 The new rules will cause existing code to break if it defines nested
537 functions where an outer function has local variables with the same
538 name as globals or builtins used by the inner function. Example:
539
540 def munge(str):
541 def helper(x):
542 return str(x)
543 if type(str) != type(''):
544 str = helper(str)
545 return str.strip()
546
547 Under the old rules, the name str in helper() is bound to the
548 builtin function str(). Under the new rules, it will be bound to
549 the argument named str and an error will occur when helper() is
550 called.
551
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000552- The compiler will report a SyntaxError if "from ... import *" occurs
553 in a function or class scope. The language reference has documented
554 that this case is illegal, but the compiler never checked for it.
555 The recent introduction of nested scope makes the meaning of this
556 form of name binding ambiguous. In a future release, the compiler
557 may allow this form when there is no possibility of ambiguity.
558
Tim Peters40ead762001-01-27 05:35:26 +0000559- repr(string) is easier to read, now using hex escapes instead of octal,
560 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
561
562 >>> "\texample \r\n" + chr(0) + chr(255)
563 '\texample \r\n\x00\xff' # in 2.1
564 '\011example \015\012\000\377' # in 2.0
565
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000566- Functions are now compared and hashed by identity, not by value, since
567 the func_code attribute is writable.
568
Fred Drakefb9d7122001-02-01 20:00:40 +0000569- Weak references (PEP 205) have been added. This involves a few
570 changes in the core, an extension module (_weakref), and a Python
571 module (weakref). The weakref module is the public interface. It
572 includes support for "explicit" weak references, proxy objects, and
573 mappings with weakly held values.
574
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000575- A 'continue' statement can now appear in a try block within the body
576 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000577 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000578
Tim Petersd7b5e882001-01-25 03:36:26 +0000579Standard library
580
Barry Warsaw30dbd142001-01-31 22:14:01 +0000581- mailbox.py now has a new class, PortableUnixMailbox which is
582 identical to UnixMailbox but uses a more portable scheme for
583 determining From_ separators. Also, the constructors for all the
584 classes in this module have a new optional `factory' argument, which
585 is a callable used when new message classes must be instantiated by
586 the next() method.
587
Tim Petersd7b5e882001-01-25 03:36:26 +0000588- random.py is now self-contained, and offers all the functionality of
589 the now-deprecated whrandom.py. See the docs for details. random.py
590 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000591 and restoring the internal state of the generator; and jumpahead(n),
592 for quickly forcing the internal state to be the same as if n calls to
593 random() had been made. The latter is particularly useful for multi-
594 threaded programs, creating one instance of the random.Random() class for
595 each thread, then using .jumpahead() to force each instance to use a
596 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000597
Tim Peters0de88fc2001-02-01 04:59:18 +0000598- random.py's seed() function is new. For bit-for-bit compatibility with
599 prior releases, use the whseed function instead. The new seed function
600 addresses two problems: (1) The old function couldn't produce more than
601 about 2**24 distinct internal states; the new one about 2**45 (the best
602 that can be done in the Wichmann-Hill generator). (2) The old function
603 sometimes produced identical internal states when passed distinct
604 integers, and there was no simple way to predict when that would happen;
605 the new one guarantees to produce distinct internal states for all
606 arguments in [0, 27814431486576L).
607
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000608- The socket module now supports raw packets on Linux. The socket
609 family is AF_PACKET.
610
Tim Peters9ea17ac2001-02-02 05:57:15 +0000611- test_capi.py is a start at running tests of the Python C API. The tests
612 are implemented by the new Modules/_testmodule.c.
613
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000614- A new extension module, _symtable, provides provisional access to the
615 internal symbol table used by the Python compiler. A higher-level
616 interface will be added on top of _symtable in a future release.
617
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000618- Removed the obsolete soundex module.
619
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000620- xml.dom.minidom now uses the standard DOM exceptions. Node supports
621 the isSameNode method; NamedNodeMap the get method.
622
623- xml.sax.expatreader supports the lexical handler property; it
624 generates comment, startCDATA, and endCDATA events.
625
Tim Petersee826f82001-01-31 19:39:44 +0000626Windows changes
627
628- Build procedure: the zlib project is built in a different way that
629 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000630 the zlib binary used. See PCbuild\readme.txt for details. Your old
631 zlib-related directories can be deleted; you'll need to download fresh
632 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000633
Tim Peters9ea17ac2001-02-02 05:57:15 +0000634- Build: New subproject _test for the benefit of test_capi.py (see above).
635
Tim Petersb16c56f2001-02-02 21:24:51 +0000636- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
637 interface to some Python compiler internals).
638
639- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000640 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000641
Tim Petersa3a3a032000-11-30 05:22:44 +0000642What's New in Python 2.1 alpha 1?
643=================================
644
645Core language, builtins, and interpreter
646
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000647- There is a new Unicode companion to the PyObject_Str() API
648 called PyObject_Unicode(). It behaves in the same way as the
649 former, but assures that the returned value is an Unicode object
650 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000651
Guido van Rossumf98eda02001-01-17 15:54:45 +0000652- The comparison operators support "rich comparison overloading" (PEP
653 207). C extension types can provide a rich comparison function in
654 the new tp_richcompare slot in the type object. The cmp() function
655 and the C function PyObject_Compare() first try the new rich
656 comparison operators before trying the old 3-way comparison. There
657 is also a new C API PyObject_RichCompare() (which also falls back on
658 the old 3-way comparison, but does not constrain the outcome of the
659 rich comparison to a Boolean result).
660
661 The rich comparison function takes two objects (at least one of
662 which is guaranteed to have the type that provided the function) and
663 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
664 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
665 object, which may be NotImplemented (in which case the tp_compare
666 slot function is used as a fallback, if defined).
667
668 Classes can overload individual comparison operators by defining one
669 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000670 __ge__. There are no explicit "reflected argument" versions of
671 these; instead, __lt__ and __gt__ are each other's reflection,
672 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
673 reflection (similar at the C level). No other implications are
674 made; in particular, Python does not assume that == is the Boolean
675 inverse of !=, or that < is the Boolean inverse of >=. This makes
676 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000677
678 Classes or types that want to implement (in)equality tests but not
679 the ordering operators (i.e. unordered types) should implement ==
680 and !=, and raise an error for the ordering operators.
681
Guido van Rossuma88479f2001-01-18 14:28:08 +0000682 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000683 Boolean; e.g. a matrix type might want to return a matrix of bits
684 for A < B, giving elementwise comparisons. Such types should ensure
685 that any interpretation of their value in a Boolean context raises
686 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
687 at the C level) to always raise an exception.
688
Guido van Rossuma88479f2001-01-18 14:28:08 +0000689- Complex numbers use rich comparisons to define == and != but raise
690 an exception for <, <=, > and >=. Unfortunately, this also means
691 that cmp() of two complex numbers raises an exception when the two
692 numbers differ. Since it is not mathematically meaningful to compare
693 complex numbers except for equality, I hope that this doesn't break
694 too much code.
695
Tim Peters3389f192001-02-18 08:48:49 +0000696- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000697 not defined by the language, other than that it's arbitrary but
698 consistent (see the Reference Manual). An implementation detail changed
699 in 2.1a1 such that None now compares less than any other object. Code
700 relying on this new behavior (like code that relied on the previous
701 behavior) does so at its own risk.
702
Barry Warsaw573b5412001-01-15 20:43:18 +0000703- Functions and methods now support getting and setting arbitrarily
704 named attributes (PEP 232). Functions have a new __dict__
705 (a.k.a. func_dict) which hold the function attributes. Methods get
706 and set attributes on their underlying im_func. It is a TypeError
707 to set an attribute on a bound method.
708
Guido van Rossum051e3352001-01-15 19:11:10 +0000709- The xrange() object implementation has been improved so that
710 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
711 limitation that in this case len(xrange(sys.maxint)) can't be
712 calculated, but the common idiom "for i in xrange(sys.maxint)" will
713 work fine as long as the index i doesn't actually reach 2**31.
714 (Python uses regular ints for sequence and string indices; fixing
715 that is much more work.)
716
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000717- Two changes to from...import:
718
Guido van Rossumba381232001-02-03 15:06:40 +0000719 1) "from M import X" now works even if (after loading module M)
720 sys.modules['M'] is not a real module; it's basically a getattr()
721 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000722
723 2) "from M import *" now looks for M.__all__ to decide which names to
724 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
725 filters out names starting with '_' as before. Whether or not
726 __all__ exists, there's no restriction on the type of M.
727
Guido van Rossumf61f1662001-01-10 20:13:55 +0000728- File objects have a new method, xreadlines(). This is the fastest
729 way to iterate over all lines in a file:
730
731 for line in file.xreadlines():
732 ...do something to line...
733
734 See the xreadlines module (mentioned below) for how to do this for
735 other file-like objects.
736
737- Even if you don't use file.xreadlines(), you may expect a speedup on
738 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000739 quite a bit in platform-specific ways: on systems (like Linux) that
740 support flockfile(), getc_unlocked(), and funlockfile(), those are
741 used by default. On systems (like Windows) without getc_unlocked(),
742 a complicated (but still thread-safe) method using fgets() is used by
743 default.
744
Tim Petersd52269b2001-01-25 06:23:18 +0000745 You can force use of the fgets() method by #define'ing
746 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000747 getc_unlocked()).
748
Tim Petersd52269b2001-01-25 06:23:18 +0000749 You can force fgets() not to be used by #define'ing
750 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000751 test_bufio.py fails -- and let us know if it does!).
752
753- In addition, the fileinput module, while still slower than the other
754 methods on most platforms, has been sped up too, by using
755 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000756
757- Support for run-time warnings has been added, including a new
758 command line option (-W) to specify the disposition of warnings.
759 See the description of the warnings module below.
760
761- Extensive changes have been made to the coercion code. This mostly
762 affects extension modules (which can now implement mixed-type
763 numerical operators without having to use coercion), but
764 occasionally, in boundary cases the coercion semantics have changed
765 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000766 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000767 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000768 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000769
Guido van Rossumf98eda02001-01-17 15:54:45 +0000770- In connection with the coercion changes, a new built-in singleton
771 object, NotImplemented is defined. This can be returned for
772 operations that wish to indicate they are not implemented for a
773 particular combination of arguments. From C, this is
774 Py_NotImplemented.
775
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000776- The interpreter accepts now bytecode files on the command line even
777 if they do not have a .pyc or .pyo extension. On Linux, after executing
778
Martin v. Löwise214baa2001-02-04 22:37:56 +0000779import imp,sys,string
780magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
781reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
782open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000783
784 any byte code file can be used as an executable (i.e. as an argument
785 to execve(2)).
786
Tim Peters9940b802000-12-01 07:59:35 +0000787- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000788 character. In 1.6 and earlier, they never produced a sign,
789 and raised an error if the value of the long was too large
790 to fit in a Python int. In 2.0, they produced a sign if and
791 only if too large to fit in an int. This was inconsistent
792 across platforms (because the size of an int varies across
793 platforms), and inconsistent with hex() and oct(). Example:
794
795 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000796 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000797 'ffffffbe' # in 2.0 and before, on 32-bit machines
798 >>> hex(-0x42L)
799 '-0x42L' # in all versions of Python
800
Tim Peters9940b802000-12-01 07:59:35 +0000801 The behavior of %d formats for negative Python longs remains
802 the same as in 2.0 (although in 1.6 and before, they raised
803 an error if the long didn't fit in a Python int).
804
805 %u formats don't make sense for Python longs, but are allowed
806 and treated the same as %d in 2.1. In 2.0, a negative long
807 formatted via %u produced a sign if and only if too large to
808 fit in an int. In 1.6 and earlier, a negative long formatted
809 via %u raised an error if it was too big to fit in an int.
810
Guido van Rossum3661d392000-12-12 22:10:31 +0000811- Dictionary objects have an odd new method, popitem(). This removes
812 an arbitrary item from the dictionary and returns it (in the form of
813 a (key, value) pair). This can be useful for algorithms that use a
814 dictionary as a bag of "to do" items and repeatedly need to pick one
815 item. Such algorithms normally end up running in quadratic time;
816 using popitem() they can usually be made to run in linear time.
817
Tim Peters36cdad12000-12-29 02:06:45 +0000818Standard library
819
Thomas Woutersfe385252001-01-19 23:16:56 +0000820- In the time module, the time argument to the functions strftime,
821 localtime, gmtime, asctime and ctime is now optional, defaulting to
822 the current time (in the local timezone).
823
Guido van Rossumda91f222001-01-15 16:36:08 +0000824- The ftplib module now defaults to passive mode, which is deemed a
825 more useful default given that clients are often inside firewalls
826 these days. Note that this could break if ftplib is used to connect
827 to a *server* that is inside a firewall, from outside; this is
828 expected to be a very rare situation. To fix that, you can call
829 ftp.set_pasv(0).
830
Martin v. Löwis10a27872001-01-13 09:54:41 +0000831- The module site now treats .pth files not only for path configuration,
832 but also supports extensions to the initialization code: Lines starting
833 with import are executed.
834
Guido van Rossumf61f1662001-01-10 20:13:55 +0000835- There's a new module, warnings, which implements a mechanism for
836 issuing and filtering warnings. There are some new built-in
837 exceptions that serve as warning categories, and a new command line
838 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
839 turns warnings into errors). warnings.warn(message[, category])
840 issues a warning message; this can also be called from C as
841 PyErr_Warn(category, message).
842
843- A new module xreadlines was added. This exports a single factory
844 function, xreadlines(). The intention is that this code is the
845 absolutely fastest way to iterate over all lines in an open
846 file(-like) object:
847
848 import xreadlines
849 for line in xreadlines.xreadlines(file):
850 ...do something to line...
851
852 This is equivalent to the previous the speed record holder using
853 file.readlines(sizehint). Note that if file is a real file object
854 (as opposed to a file-like object), this is equivalent:
855
856 for line in file.xreadlines():
857 ...do something to line...
858
Tim Peters36cdad12000-12-29 02:06:45 +0000859- The bisect module has new functions bisect_left, insort_left,
860 bisect_right and insort_right. The old names bisect and insort
861 are now aliases for bisect_right and insort_right. XXX_right
862 and XXX_left methods differ in what happens when the new element
863 compares equal to one or more elements already in the list: the
864 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000865 right. Code that doesn't care where equal elements end up should
866 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000867
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000868- The new curses.panel module wraps the panel library that forms part
869 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
870
Guido van Rossumf61f1662001-01-10 20:13:55 +0000871- The SocketServer module now sets the allow_reuse_address flag by
872 default in the TCPServer class.
873
874- A new function, sys._getframe(), returns the stack frame pointer of
875 the caller. This is intended only as a building block for
876 higher-level mechanisms such as string interpolation.
877
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000878- The pyexpat module supports a number of new handlers, which are
879 available only in expat 1.2. If invocation of a callback fails, it
880 will report an additional frame in the traceback. Parser objects
881 participate now in garbage collection. If expat reports an unknown
882 encoding, pyexpat will try to use a Python codec; that works only
883 for single-byte charsets. The parser type objects is exposed as
884 XMLParserObject.
885
886- xml.dom now offers standard definitions for symbolic node type and
887 exception code constants, and a hierarchy of DOM exceptions. minidom
888 was adjusted to use them.
889
890- The conformance of xml.dom.minidom to the DOM specification was
891 improved. It detects a number of additional error cases; the
892 previous/next relationship works even when the tree is modified;
893 Node supports the normalize() method; NamedNodeMap, DocumentType and
894 DOMImplementation classes were added; Element supports the
895 hasAttribute and hasAttributeNS methods; and Text supports the splitText
896 method.
897
Guido van Rossumf61f1662001-01-10 20:13:55 +0000898Build issues
899
Guido van Rossum1e33bdc2001-01-23 03:17:00 +0000900- For Unix (and Unix-compatible) builds, configuration and building of
901 extension modules is now greatly automated. Rather than having to
902 edit the Modules/Setup file to indicate which modules should be
903 built and where their include files and libraries are, a
904 distutils-based setup.py script now takes care of building most
905 extension modules. All extension modules built this way are built
906 as shared libraries. Only a few modules that must be linked
907 statically are still listed in the Setup file; you won't need to
908 edit their configuration.
909
910- Python should now build out of the box on Cygwin. If it doesn't,
911 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000912
913- Python now always uses its own (renamed) implementation of getopt()
914 -- there's too much variation among C library getopt()
915 implementations.
916
917- C++ compilers are better supported; the CXX macro is always set to a
918 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +0000919
Tim Petersd92dfe02000-12-12 01:18:41 +0000920Windows changes
921
922- select module: By default under Windows, a select() call
923 can specify no more than 64 sockets. Python now boosts
924 this Microsoft default to 512. If you need even more than
925 that, see the MS docs (you'll need to #define FD_SETSIZE
926 and recompile Python from source).
927
Guido van Rossumf61f1662001-01-10 20:13:55 +0000928- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
929 subdirectory is no more!
930
Tim Petersa3a3a032000-11-30 05:22:44 +0000931
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000932What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +0000933=========================
Guido van Rossum61000331997-08-15 04:39:58 +0000934
Guido van Rossum8ed602b2000-09-01 22:34:33 +0000935Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000936changes are in the file HISTORY. If you are making the jump directly
937from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
938HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +0000939
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000940Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
941the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
942http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +0000943
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000944--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +0000945
946======================================================================
947
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000948What's new in 2.0 (since release candidate 1)?
949==============================================
950
951Standard library
952
953- The copy_reg module was modified to clarify its intended use: to
954 register pickle support for extension types, not for classes.
955 pickle() will raise a TypeError if it is passed a class.
956
957- Fixed a bug in gettext's "normalize and expand" code that prevented
958 it from finding an existing .mo file.
959
960- Restored support for HTTP/0.9 servers in httplib.
961
Tim Peters989b7b92000-10-16 20:24:53 +0000962- The math module was changed to stop raising OverflowError in case of
963 underflow, and return 0 instead in underflow cases. Whether Python
964 used to raise OverflowError in case of underflow was platform-
965 dependent (it did when the platform math library set errno to ERANGE
966 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000967
968- Fixed a bug in StringIO that occurred when the file position was not
969 at the end of the file and write() was called with enough data to
970 extend past the end of the file.
971
972- Fixed a bug that caused Tkinter error messages to get lost on
973 Windows. The bug was fixed by replacing direct use of
974 interp->result with Tcl_GetStringResult(interp).
975
976- Fixed bug in urllib2 that caused it to fail when it received an HTTP
977 redirect response.
978
979- Several changes were made to distutils: Some debugging code was
980 removed from util. Fixed the installer used when an external zip
981 program (like WinZip) is not found; the source code for this
982 installer is in Misc/distutils. check_lib() was modified to behave
983 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
984 test for whether installed modules are on sys.path was changed to
985 use both normcase() and normpath().
986
Jeremy Hyltond867a2c2000-10-16 20:41:38 +0000987- Several minor bugs were fixed in the xml package (the minidom,
988 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000989
990- The regression test driver (regrtest.py) behavior when invoked with
991 -l changed: It now reports a count of objects that are recognized as
992 garbage but not freed by the garbage collector.
993
Tim Peters989b7b92000-10-16 20:24:53 +0000994- The regression test for the math module was changed to test
995 exceptional behavior when the test is run in verbose mode. Python
996 cannot yet guarantee consistent exception behavior across platforms,
997 so the exception part of test_math is run only in verbose mode, and
998 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000999
1000Internals
1001
1002- PyOS_CheckStack() has been disabled on Win64, where it caused
1003 test_sre to fail.
1004
1005Build issues
1006
1007- Changed compiler flags, so that gcc is always invoked with -Wall and
1008 -Wstrict-prototypes. Users compiling Python with GCC should see
1009 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001010 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001011 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001012
Tim Petersa3a3a032000-11-30 05:22:44 +00001013- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001014
1015Tools and other miscellany
1016
1017- The compiler in Tools/compiler was updated to support the new
1018 language features introduced in 2.0: extended print statement, list
1019 comprehensions, and augmented assignments. The new compiler should
1020 also be backwards compatible with Python 1.5.2; the compiler will
1021 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001022 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001023
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001024What's new in 2.0 release candidate 1 (since beta 2)?
1025=====================================================
1026
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001027What is release candidate 1?
1028
1029We believe that release candidate 1 will fix all known bugs that we
1030intend to fix for the 2.0 final release. This release should be a bit
1031more stable than the previous betas. We would like to see even more
1032widespread testing before the final release, so we are producing this
1033release candidate. The final release will be exactly the same unless
1034any show-stopping (or brown bag) bugs are found by testers of the
1035release candidate.
1036
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001037All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001038to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001039
1040Core language, builtins, and interpreter
1041
1042- A bug that caused crashes when __coerce__ was used with augmented
1043 assignment, e.g. +=, was fixed.
1044
1045- Raise ZeroDivisionError when raising zero to a negative number,
1046 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1047 power operator and the result of math.pow(0.0, -2.0) will vary by
1048 platform. On Linux, it raises a ValueError.
1049
1050- A bug in Unicode string interpolation was fixed that occasionally
1051 caused errors with formats including "%%". For example, the
1052 following expression "%% %s" % u"abc" no longer raises a TypeError.
1053
1054- Compilation of deeply nested expressions raises MemoryError instead
1055 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1056
1057- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1058 rendering them useless. They are now written in binary mode again.
1059
1060Standard library
1061
1062- Keyword arguments are now accepted for most pattern and match object
1063 methods in SRE, the standard regular expression engine.
1064
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001065- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001066 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001067
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001068- Several bugs in the Unicode handling and error handling in _tkinter
1069 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001070
1071- Fix memory management errors in Merge() and Tkapp_Call() routines.
1072
1073- Several changes were made to cStringIO to make it compatible with
1074 the file-like object interface and with StringIO. If operations are
1075 performed on a closed object, an exception is raised. The truncate
1076 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001077 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001078
1079- There were many changes made to the linuxaudiodev module and its
1080 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001081 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001082
1083 Note that this module is named poorly, because it should work
1084 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001085 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001086
1087 The module now raises exceptions when errors occur instead of
1088 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1089 audio) and defines a getptr() method that calls the
1090 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1091
1092- The library_version attribute, introduced in an earlier beta, was
1093 removed because it can not be supported with early versions of the C
1094 readline library, which provides no way to determine the version at
1095 compile-time.
1096
1097- The binascii module is now enabled on Win64.
1098
Tim Peters46446d62000-10-09 21:19:31 +00001099- tokenize.py no longer suffers "recursion depth" errors when parsing
1100 programs with very long string literals.
1101
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001102Internals
1103
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001104- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001105 which is called when the interpreter starts up to determine where
1106 the standard library is installed. These vulnerabilities affect all
1107 previous versions of Python and can be exploited by setting very
1108 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1109 setuid Python script, although use of the wrapper in
1110 Misc/setuid-prog.c will eliminate the vulnerability.
1111
1112- Fixed garbage collection bugs in instance creation that were
1113 triggered when errors occurred during initialization. The solution,
1114 applied in cPickle and in PyInstance_New(), is to call
1115 PyObject_GC_Init() after the initialization of the object's
1116 container attributes is complete.
1117
1118- pyexpat adds definitions of PyModule_AddStringConstant and
1119 PyModule_AddObject if the Python version is less than 2.0, which
1120 provides compatibility with PyXML on Python 1.5.2.
1121
1122- If the platform has a bogus definition for LONG_BIT (the number of
1123 bits in a long), an error will be reported at compile time.
1124
1125- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1126 collection crashes and possibly other, unreported crashes.
1127
1128- Fixed a memory leak in _PyUnicode_Fini().
1129
1130Build issues
1131
1132- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001133 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001134 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001135
1136- The mmap.PAGESIZE constant is now initialized using sysconf when
1137 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1138
1139- The md5 file should now compile on all platforms.
1140
1141- The select module now compiles on platforms that do not define
1142 POLLRDNORM and related constants.
1143
1144- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001145 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001146
Jeremy Hylton10921202000-10-09 18:34:12 +00001147- BeOS: A number of changes were made to the build and installation
1148 process. ar-fake now operates on a directory of object files.
1149 dl_export.h is gone, and its macros now appear on the mwcc command
1150 line during build on PPC BeOS.
1151
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001152- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001153 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001154
1155- Cygwin: Support for shared libraries, Tkinter, and sockets.
1156
1157- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1158
1159Tools and other miscellany
1160
1161- Removed debugging prints from main used with freeze.
1162
Tim Peters46446d62000-10-09 21:19:31 +00001163- IDLE auto-indent no longer crashes when it encounters Unicode
1164 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001165
1166What's new in 2.0 beta 2 (since beta 1)?
1167========================================
1168
1169Core language, builtins, and interpreter
1170
Tim Peters482c0212000-09-26 06:33:09 +00001171- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001172 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001173
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001174- Add -h and -V command line options to print the usage message and
1175 Python version number and exit immediately.
1176
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001177- eval() and exec accept Unicode objects as code parameters.
1178
1179- getattr() and setattr() now also accept Unicode objects for the
1180 attribute name, which are converted to strings using the default
1181 encoding before lookup.
1182
1183- Multiplication on string and Unicode now does proper bounds
1184 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1185 string is too long."
1186
1187- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001188 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001189
Jeremy Hylton1b618592000-09-26 05:32:36 +00001190
1191Standard library and extensions
1192
Guido van Rossum5b08f132001-04-16 02:05:23 +00001193- socket module: the OpenSSL code now adds support for RAND_status()
1194 and EGD (Entropy Gathering Device).
1195
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001196- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001197 argument checking; it still takes no arguments.
1198
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001199- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001200
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001201- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001202
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001203- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001204
1205- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001206 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001207
1208- copy: Copy Unicode objects atomically.
1209
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001210- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001211
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001212- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001213
Fred Drake67233bc2000-09-26 16:40:27 +00001214- dbm: Add get() and setdefault() methods to dbm object. Add constant
1215 `library' to module that names the library used. Added doc strings
1216 and method names to error messages. Uses configure to determine
1217 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1218 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001219
1220- distutils: Update to version 0.9.3.
1221
1222- dl: Add several dl.RTLD_ constants.
1223
1224- fpectl: Now supported on FreeBSD.
1225
1226- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1227 found by the collector will be saved in gc.garbage. This is useful
1228 for debugging a program that creates reference cycles.
1229
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001230- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001231 of HTTP class. Do not close socket on zero-length response. Do not
1232 crash when server sends invalid content-length header.
1233
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001234- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001235
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001236- marshal: When reading a short, sign-extend on platforms where shorts
1237 are bigger than 16 bits. When reading a long, repair the unportable
1238 sign extension that was being done for 64-bit machines. (It assumed
1239 that signed right shift sign-extends.)
1240
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001241- operator: Add contains(), invert(), __invert__() as aliases for
1242 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001243
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001244- os: Add support for popen2() and popen3() on all platforms where
1245 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001246
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001247- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001248 clicking on a file in Explorer (or passing the file name to the
1249 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001250
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001251- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001252 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001253
1254- pickle: Now raises ValueError when an invalid pickle that contains
1255 a non-string repr where a string repr was expected. This behavior
1256 matches cPickle.
1257
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001258- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001259
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001260- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001261
1262- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001263 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001264 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001265
1266- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001267 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001268
1269- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001270 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001271 few cycles during startup since the first call to
1272 setdefaultencoding() will initialize the codec registry and the
1273 encodings package.
1274
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001275- socket: Support for size hint in readlines() method of object returned
1276 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001277
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001278- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001279 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001280 is followed by whitespace.
1281
Tim Petersa3a3a032000-11-30 05:22:44 +00001282- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001283
1284- struct: Check ranges for bytes and shorts.
1285
1286- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001287 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001288
1289- Tkinter: Image objects are now guaranteed to have unique ids. Set
1290 event.delta to zero if Tk version doesn't support mousewheel.
1291 Removed some debugging prints.
1292
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001293- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001294
Fred Drake67233bc2000-09-26 16:40:27 +00001295- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001296 which works around a bug in Norton AntiVirus 2000 that leads directly
1297 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001298
1299- xml: New version detection code allows PyXML to override standard
1300 XML package if PyXML version is greater than 0.6.1.
1301
Fred Drake64bb3802000-09-26 16:21:35 +00001302- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1303 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1304 tree only for nodes which are sufficiently interesting to a specific
1305 application. Does not provide the HTML-specific extensions. Still
1306 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001307
Fred Drake64bb3802000-09-26 16:21:35 +00001308- xml.sax: SAX 2 support for Python, including all the handler
1309 interfaces needed to process XML 1.0 compliant XML. Some
1310 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001311
Fred Drake64bb3802000-09-26 16:21:35 +00001312- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1313 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001314
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001315
Jeremy Hylton1b618592000-09-26 05:32:36 +00001316C API
1317
1318- Add three new convenience functions for module initialization --
1319 PyModule_AddObject(), PyModule_AddIntConstant(), and
1320 PyModule_AddStringConstant().
1321
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001322- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001323 removed and add #error to Python.h if NULL isn't defined after
1324 #include of stdio.h.
1325
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001326- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001327 backwards compatibility (at the source level) with old extensions.
1328
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001329- A wrapper API was added for signal() and sigaction(). Instead of
1330 either function, always use PyOS_getsig() to get a signal handler
1331 and PyOS_setsig() to set one. A new convenience typedef
1332 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001333
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001334- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001335 internal data buffer and size of a string object -- or the default
1336 encoded version of a Unicode object.
1337
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001338- PyString_Size() and PyString_AsString() accept Unicode objects.
1339
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001340- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001341 exists). INT_MAX and LONG_MAX will always be defined, even if
1342 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001343
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001344- PyFloat_FromString takes a second argument, pend, that was
1345 effectively useless. It is now officially useless but preserved for
1346 backwards compatibility. If the pend argument is not NULL, *pend is
1347 set to NULL.
1348
1349- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1350 for the attribute name. See note on getattr() above.
1351
1352- A few bug fixes to argument processing for Unicode.
1353 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1354 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1355 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001356 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001357
1358- Py_BuildValue accepts B format (for bgen-generated code).
1359
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001360
Jeremy Hylton1b618592000-09-26 05:32:36 +00001361Internals
1362
1363- On Unix, fix code for finding Python installation directory so that
1364 it works when argv[0] is a relative path.
1365
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001366- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001367 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001368 rather than by generating a copy of the object.
1369
Tim Peters482c0212000-09-26 06:33:09 +00001370- Several of the internal Unicode tables are much smaller now, and
1371 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001372
Jeremy Hylton97693b02000-09-26 17:42:51 +00001373- In the garbage collector: Fixed bug in collection of tuples. Fixed
1374 bug that caused some instances to be removed from the container set
1375 while they were still live. Fixed parsing in gc.set_debug() for
1376 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001377
1378- Fixed refcount problem in instance deallocation that only occurred
1379 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1380
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001381- On Windows, getpythonregpath is now protected against null data in
1382 registry key.
1383
1384- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001385 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001386
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001387
Jeremy Hylton1b618592000-09-26 05:32:36 +00001388Build and platform-specific issues
1389
1390- Better support of GNU Pth via --with-pth configure option.
1391
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001392- Python/C API now properly exposed to dynamically-loaded extension
1393 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001394
1395- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1396 Don't define MS_SYNC to be zero when it is undefined. Added missing
1397 prototypes in posixmodule.c.
1398
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001399- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001400 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001401
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001402- Fix largefile support on older NetBSD systems and OpenBSD by adding
1403 define for TELL64.
1404
1405
1406Tools and other miscellany
1407
1408- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1409
1410- freeze: The modulefinder now works with 2.0 opcodes.
1411
Tim Petersa3a3a032000-11-30 05:22:44 +00001412- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001413 Move hackery of sys.argv until after the Tk instance has been
1414 created, which allows the application-specific Tkinter
1415 initialization to be executed if present; also pass an explicit
1416 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001417
Jeremy Hylton1b618592000-09-26 05:32:36 +00001418
1419What's new in 2.0 beta 1?
1420=========================
1421
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001422Source Incompatibilities
1423------------------------
1424
1425None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1426such as single-argument append(), connect() and bind(), and changes to
1427str(long) and repr(float).
1428
1429
1430Binary Incompatibilities
1431------------------------
1432
1433- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1434with Python 2.0; these extensions will have to be rebuilt for Python
14352.0.
1436
1437- On Windows, attempting to import a third party extension built for
1438Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1439can do about this. Check your PYTHONPATH environment variable!
1440
1441- Python bytecode files (*.pyc and *.pyo) are not compatible between
1442releases.
1443
1444
1445Overview of Changes Since 1.6
1446-----------------------------
1447
1448There are many new modules (including brand new XML support through
1449the xml package, and i18n support through the gettext module); a list
1450of all new modules is included below. Lots of bugs have been fixed.
1451
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001452The process for making major new changes to the language has changed
1453since Python 1.6. Enhancements must now be documented by a Python
1454Enhancement Proposal (PEP) before they can be accepted.
1455
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001456There are several important syntax enhancements, described in more
1457detail below:
1458
1459 - Augmented assignment, e.g. x += 1
1460
1461 - List comprehensions, e.g. [x**2 for x in range(10)]
1462
1463 - Extended import statement, e.g. import Module as Name
1464
1465 - Extended print statement, e.g. print >> file, "Hello"
1466
1467Other important changes:
1468
1469 - Optional collection of cyclical garbage
1470
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001471Python Enhancement Proposal (PEP)
1472---------------------------------
1473
1474PEP stands for Python Enhancement Proposal. A PEP is a design
1475document providing information to the Python community, or describing
1476a new feature for Python. The PEP should provide a concise technical
1477specification of the feature and a rationale for the feature.
1478
1479We intend PEPs to be the primary mechanisms for proposing new
1480features, for collecting community input on an issue, and for
1481documenting the design decisions that have gone into Python. The PEP
1482author is responsible for building consensus within the community and
1483documenting dissenting opinions.
1484
1485The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001486
1487Augmented Assignment
1488--------------------
1489
1490This must have been the most-requested feature of the past years!
1491Eleven new assignment operators were added:
1492
Guido van Rossume905e952000-09-05 12:42:46 +00001493 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001494
1495For example,
1496
1497 A += B
1498
1499is similar to
1500
1501 A = A + B
1502
1503except that A is evaluated only once (relevant when A is something
1504like dict[index].attr).
1505
1506However, if A is a mutable object, A may be modified in place. Thus,
1507if A is a number or a string, A += B has the same effect as A = A+B
1508(except A is only evaluated once); but if a is a list, A += B has the
1509same effect as A.extend(B)!
1510
1511Classes and built-in object types can override the new operators in
1512order to implement the in-place behavior; the not-in-place behavior is
1513used automatically as a fallback when an object doesn't implement the
1514in-place behavior. For classes, the method name is derived from the
1515method name for the corresponding not-in-place operator by inserting
1516an 'i' in front of the name, e.g. __iadd__ implements in-place
1517__add__.
1518
1519Augmented assignment was implemented by Thomas Wouters.
1520
1521
1522List Comprehensions
1523-------------------
1524
1525This is a flexible new notation for lists whose elements are computed
1526from another list (or lists). The simplest form is:
1527
1528 [<expression> for <variable> in <sequence>]
1529
Guido van Rossum56db0952000-09-06 23:34:25 +00001530For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001531This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001532
1533You can also add a condition:
1534
1535 [<expression> for <variable> in <sequence> if <condition>]
1536
1537For example, [w for w in words if w == w.lower()] would yield the list
1538of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001539than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001540
1541You can also have nested for loops and more than one 'if' clause. For
1542example, here's a function that flattens a sequence of sequences::
1543
1544 def flatten(seq):
1545 return [x for subseq in seq for x in subseq]
1546
1547 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1548
1549This prints
1550
1551 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1552
1553List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001554Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001555
1556
1557Extended Import Statement
1558-------------------------
1559
1560Many people have asked for a way to import a module under a different
1561name. This can be accomplished like this:
1562
1563 import foo
1564 bar = foo
1565 del foo
1566
1567but this common idiom gets old quickly. A simple extension of the
1568import statement now allows this to be written as follows:
1569
1570 import foo as bar
1571
1572There's also a variant for 'from ... import':
1573
1574 from foo import bar as spam
1575
1576This also works with packages; e.g. you can write this:
1577
1578 import test.regrtest as regrtest
1579
1580Note that 'as' is not a new keyword -- it is recognized only in this
1581context (this is only possible because the syntax for the import
1582statement doesn't involve expressions).
1583
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001584Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001585
1586
1587Extended Print Statement
1588------------------------
1589
1590Easily the most controversial new feature, this extension to the print
1591statement adds an option to make the output go to a different file
1592than the default sys.stdout.
1593
1594For example, to write an error message to sys.stderr, you can now
1595write:
1596
1597 print >> sys.stderr, "Error: bad dog!"
1598
1599As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001600evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001601
1602 print >> None, "Hello world"
1603
1604is equivalent to
1605
1606 print "Hello world"
1607
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001608Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001609
1610
1611Optional Collection of Cyclical Garbage
1612---------------------------------------
1613
1614Python is now equipped with a garbage collector that can hunt down
1615cyclical references between Python objects. It's no replacement for
1616reference counting; in fact, it depends on the reference counts being
1617correct, and decides that a set of objects belong to a cycle if all
1618their reference counts can be accounted for from their references to
1619each other. This devious scheme was first proposed by Eric Tiedemann,
1620and brought to implementation by Neil Schemenauer.
1621
1622There's a module "gc" that lets you control some parameters of the
1623garbage collection. There's also an option to the configure script
1624that lets you enable or disable the garbage collection. In 2.0b1,
1625it's on by default, so that we (hopefully) can collect decent user
1626experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001627performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001628off by default in the final 2.0 release.
1629
1630
1631Smaller Changes
1632---------------
1633
1634A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1635map(None, seq1, seq2, ...) when the sequences have the same length;
1636i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1637the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001638zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001639
1640sys.version_info is a tuple (major, minor, micro, level, serial).
1641
1642Dictionaries have an odd new method, setdefault(key, default).
1643dict.setdefault(key, default) returns dict[key] if it exists; if not,
1644it sets dict[key] to default and returns that value. Thus:
1645
1646 dict.setdefault(key, []).append(item)
1647
1648does the same work as this common idiom:
1649
1650 if not dict.has_key(key):
1651 dict[key] = []
1652 dict[key].append(item)
1653
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001654There are two new variants of SyntaxError that are raised for
1655indentation-related errors: IndentationError and TabError.
1656
1657Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1658escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001659
1660The limits on the size of expressions and file in Python source code
1661have been raised from 2**16 to 2**32. Previous versions of Python
1662were limited because the maximum argument size the Python VM accepted
1663was 2**16. This limited the size of object constructor expressions,
1664e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1665limit was raised thanks to a patch by Charles Waldman that effectively
1666fixes the problem. It is now much more likely that you will be
1667limited by available memory than by an arbitrary limit in Python.
1668
1669The interpreter's maximum recursion depth can be modified by Python
1670programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1671limit is the maximum number of recursive calls that can be made by
1672Python code. The limit exists to prevent infinite recursion from
1673overflowing the C stack and causing a core dump. The default value is
16741000. The maximum safe value for a particular platform can be found
1675by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001676
1677New Modules and Packages
1678------------------------
1679
1680atexit - for registering functions to be called when Python exits.
1681
1682imputil - Greg Stein's alternative API for writing custom import
1683hooks.
1684
1685pyexpat - an interface to the Expat XML parser, contributed by Paul
1686Prescod.
1687
1688xml - a new package with XML support code organized (so far) in three
1689subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1690would fill a volume. There's a special feature whereby a
1691user-installed package named _xmlplus overrides the standard
1692xmlpackage; this is intended to give the XML SIG a hook to distribute
1693backwards-compatible updates to the standard xml package.
1694
1695webbrowser - a platform-independent API to launch a web browser.
1696
1697
Guido van Rossume905e952000-09-05 12:42:46 +00001698Changed Modules
1699---------------
1700
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001701array -- new methods for array objects: count, extend, index, pop, and
1702remove
1703
1704binascii -- new functions b2a_hex and a2b_hex that convert between
1705binary data and its hex representation
1706
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001707calendar -- Many new functions that support features including control
1708over which day of the week is the first day, returning strings instead
1709of printing them. Also new symbolic constants for days of week,
1710e.g. MONDAY, ..., SUNDAY.
1711
1712cgi -- FieldStorage objects have a getvalue method that works like a
1713dictionary's get method and returns the value attribute of the object.
1714
1715ConfigParser -- The parser object has new methods has_option,
1716remove_section, remove_option, set, and write. They allow the module
1717to be used for writing config files as well as reading them.
1718
1719ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001720optionally support the RFC 959 REST command.
1721
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001722gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001723
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001724httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1725the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001726
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001727locale -- implement getdefaultlocale for Win32 and Macintosh
1728
1729marshal -- no longer dumps core when marshaling deeply nested or
1730recursive data structures
1731
1732os -- new functions isatty, seteuid, setegid, setreuid, setregid
1733
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001734os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1735support under Unix.
1736
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001737os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001738
1739os.path -- fix semantics of os.path.commonprefix
1740
1741smtplib -- support for sending very long messages
1742
1743socket -- new function getfqdn()
1744
1745readline -- new functions to read, write and truncate history files.
1746The readline section of the library reference manual contains an
1747example.
1748
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001749select -- add interface to poll system call
1750
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001751shutil -- new copyfileobj function
1752
1753SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1754HTTP server.
1755
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001756Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001757
1758urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001759e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001760
1761whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001762
1763
1764Obsolete Modules
1765----------------
1766
1767None. However note that 1.6 made a whole slew of modules obsolete:
1768stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1769poly, zmod, strop, util, whatsound.
1770
1771
1772Changed, New, Obsolete Tools
1773----------------------------
1774
Tim Peters8b092332000-09-05 20:15:25 +00001775None.
Guido van Rossume905e952000-09-05 12:42:46 +00001776
1777
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001778C-level Changes
1779---------------
1780
1781Several cleanup jobs were carried out throughout the source code.
1782
1783All C code was converted to ANSI C; we got rid of all uses of the
1784Py_PROTO() macro, which makes the header files a lot more readable.
1785
1786Most of the portability hacks were moved to a new header file,
1787pyport.h; several other new header files were added and some old
1788header files were removed, in an attempt to create a more rational set
1789of header files. (Few of these ever need to be included explicitly;
1790they are all included by Python.h.)
1791
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001792Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001793and Win64, especially for the new Intel Itanium processor. Mick also
1794added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001795
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001796The C APIs to return an object's size have been update to consistently
1797use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1798previous versions, the abstract interfaces used PyXXX_Length and the
1799concrete interfaces used PyXXX_Size. The old names,
1800e.g. PyObject_Length, are still available for backwards compatibility
1801at the API level, but are deprecated.
1802
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001803The PyOS_CheckStack function has been implemented on Windows by
1804Fredrik Lundh. It prevents Python from failing with a stack overflow
1805on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001806
1807The GC changes resulted in creation of two new slots on object,
1808tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001809the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001810
1811The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001812C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001813
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001814PyErr_Format has been updated to automatically calculate the size of
1815the buffer needed to hold the formatted result string. This change
1816prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001817
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001818New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001819
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001820PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1821that are the same as their non-Ex counterparts except they take an
1822extra flag argument that tells them to close the file when done.
1823
1824XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001825
Tim Peters8b092332000-09-05 20:15:25 +00001826
1827Windows Changes
1828---------------
1829
1830New popen2/popen3/peopen4 in os module (see Changed Modules above).
1831
1832os.popen is much more usable on Windows 95 and 98. See Microsoft
1833Knowledge Base article Q150956. The Win9x workaround described there
1834is implemented by the new w9xpopen.exe helper in the root of your
1835Python installation. Note that Python uses this internally; it is not
1836a standalone program.
1837
1838Administrator privileges are no longer required to install Python
1839on Windows NT or Windows 2000. If you have administrator privileges,
1840Python's registry info will be written under HKEY_LOCAL_MACHINE.
1841Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001842under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001843uses of Python, but will prevent some advanced uses from working
1844(for example, running a Python script as an NT service, or possibly
1845from CGI).
1846
1847[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1848installer; instead, it installs the needed Tcl/Tk files directly in the
1849Python directory. If you already have a Tcl/Tk installation, this
1850wastes some disk space (about 4 Megs) but avoids problems with
1851conflicting Tcl/Tk installations, and makes it much easier for Python
1852to ensure that Tcl/Tk can find all its files.
1853
1854[This was new in 1.6] The Windows installer now installs by default in
1855\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1856
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001857
1858Updates to the changes between 1.5.2 and 1.6
1859--------------------------------------------
1860
1861The 1.6 NEWS file can't be changed after the release is done, so here
1862is some late-breaking news:
1863
1864New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1865and changes to getlocale() and setlocale().
1866
1867The new module is now enabled per default.
1868
1869It is not true that the encodings codecs cannot be used for normal
1870strings: the string.encode() (which is also present on 8-bit strings
1871!) allows using them for 8-bit strings too, e.g. to convert files from
1872cp1252 (Windows) to latin-1 or vice-versa.
1873
1874Japanese codecs are available from Tamito KAJIYAMA:
1875http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1876
1877
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001878======================================================================