blob: 9a343ad42730934aa18ffa0e7995405a85b0aba2 [file] [log] [blame]
Tim Petersf553f892001-05-01 20:45:31 +00001What's New in Python 2.2a0?
2===========================
3
4Core
Tim Petersa814db52001-05-14 07:05:58 +00005
Mark Hammond2a0af792001-05-14 03:09:36 +00006- Some operating systems now support the concept of a default Unicode
7 encoding for file system operations. Notably, Windows supports 'mbcs'
8 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00009 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000010 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000011
12 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000013 functions that return filenames (such as os.listdir()) to return Python
14 string objects pre-encoded using the default file system encoding for
15 the platform. As this encoding is likely to be different from Python's
16 default encoding, converting this name to a Unicode object before passing
17 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000018 would attempt to use its default encoding (generally ASCII) rather than
19 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000020
Tim Petersa814db52001-05-14 07:05:58 +000021 In general, this change simply removes surprises when working with
22 Unicode and the file system, making these operations work as you expect,
23 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +000024 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +000025
Tim Peters61dff2b2001-05-08 15:43:37 +000026- Float (and complex) literals in source code were evaluated to full
27 precision only when running from a .py file; the same code loaded from a
28 .pyc (or .pyo) file could suffer numeric differences starting at about the
29 12th significant decimal digit. For example, on a machine with IEEE-754
30 floating arithmetic,
31
32 x = 9007199254740992.0
33 print long(x)
34
35 printed 9007199254740992 if run directly from .py, but 9007199254740000
36 if from a compiled (.pyc or .pyo) file. This was due to marshal using
37 str(float) instead of repr(float) when building code objects. marshal
38 now uses repr(float) instead, which should reproduce floats to full
39 machine precision (assuming the platform C float<->string I/O conversion
40 functions are of good quality).
41
42 This may cause floating-point results to change in some cases, and
43 usually for the better, but may also cause numerically unstable
44 algorithms to break.
45
Tim Peters2f228e72001-05-13 00:19:31 +000046- The implementation of dicts suffers fewer collisions, which has speed
47 benefits. However, the order in which dict entries appear in dict.keys(),
48 dict.values() and dict.items() may differ from previous releases for a
49 given dict. Nothing is defined about this order, so no program should
50 rely on it. Nevertheless, it's easy to write test cases that rely on the
51 order by accident, typically because of printing the str() or repr() of a
52 dict to an "expected results" file. See Lib/test/test_support.py's new
53 sortdict(dict) function for a simple way to display a dict in sorted
54 order.
55
Guido van Rossum10315822001-05-01 20:54:30 +000056- Dictionary objects now support the "in" operator: "x in dict" means
57 the same as dict.has_key(x).
58
59- Iterators were added; this is a generalized way of providing values
60 to a for loop. See PEP 234. There's a new built-in function iter()
61 to return an iterator. There's a new protocol to get the next value
62 from an iterator using the next() method (in Python) or the
63 tp_iternext slot (in C). There's a new protocol to get iterators
64 using the __iter__() method (in Python) or the tp_iter slot (in C).
65 Iterating (i.e. a for loop) over a dictionary generates its keys.
66 Iterating over a file generates its lines.
67
Tim Petersf553f892001-05-01 20:45:31 +000068- The following functions were generalized to work nicely with iterator
69 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +000070 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +000071 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
72 max(), min()
Tim Petersde9725f2001-05-05 10:06:17 +000073 .join() method of strings
Tim Peters75f8e352001-05-05 11:33:43 +000074 'x in y' and 'x not in y' (PySequence_Contains() in C API)
75 operator.countOf() (PySequence_Count() in C API)
Tim Peters75f8e352001-05-05 11:33:43 +000076
Tim Petersd85e1022001-05-11 21:51:48 +000077- Accessing module attributes is significantly faster (for example,
78 random.random or os.path or yourPythonModule.yourAttribute).
79
Tim Peterse63415e2001-05-08 04:38:29 +000080- Comparing dictionary objects via == and != is faster, and now works even
81 if the keys and values don't support comparisons other than ==.
82
Tim Peters95bf9392001-05-10 08:32:44 +000083- Comparing dictionaries in ways other than == and != is slower: there were
84 insecurities in the dict comparison implementation that could cause Python
85 to crash if the element comparison routines for the dict keys and/or
86 values mutated the dicts. Making the code bulletproof slowed it down.
87
Tim Petersa814db52001-05-14 07:05:58 +000088Library
89
90- Cookie.py now sorts key+value pairs by key in output strings.
91
92- pprint.isrecursive(object) didn't correctly identify recursive objects.
93 Now it does.
94
95Tests
96
97- New test_mutants.py runs dict comparisons where the key and value
98 comparison operators mutute the dicts randomly during comparison. This
99 rapidly causes Python to crash under earlier releases (not for the faint
100 of heart: it can also cause Win9x to freeze or reboot!).
101
102- New test_pprint.py verfies that pprint.isrecursive() and
103 pprint.isreadable() return sensible results.
104
Tim Petersf553f892001-05-01 20:45:31 +0000105
Guido van Rossumffe13be2001-04-16 18:46:45 +0000106What's New in Python 2.1 (final)?
107=================================
108
109We only changed a few things since the last release candidate, all in
110Python library code:
111
112- A bug in the locale module was fixed that affected locales which
113 define no grouping for numeric formatting.
114
115- A few bugs in the weakref module's implementations of weak
116 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
117 and the test suite was updated to check for these bugs.
118
119- An old bug in the os.path.walk() function (introduced in Python
120 2.0!) was fixed: a non-existent file would cause an exception
121 instead of being ignored.
122
123- Fixed a few bugs in the new symtable module found by Neil Norwitz's
124 PyChecker.
125
126
Guido van Rossum5b08f132001-04-16 02:05:23 +0000127What's New in Python 2.1c2?
128===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000129
Guido van Rossum5b08f132001-04-16 02:05:23 +0000130A flurry of small changes, and one showstopper fixed in the nick of
131time made it necessary to release another release candidate. The list
132here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000133
Guido van Rossum5b08f132001-04-16 02:05:23 +0000134Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000135
Guido van Rossum5b08f132001-04-16 02:05:23 +0000136- Tim discovered a nasty bug in the dictionary code, caused by
137 PyDict_Next() calling dict_resize(), and the GC code's use of
138 PyDict_Next() violating an assumption in dict_items(). This was
139 fixed with considerable amounts of band-aid, but the net effect is a
140 saner and more robust implementation.
141
142- Made a bunch of symbols static that were accidentally global.
143
144Build and Ports
145
146- The setup.py script didn't check for a new enough version of zlib
147 (1.1.3 is needed). Now it does.
148
149- Changed "make clean" target to also remove shared libraries.
150
151- Added a more general warning about the SGI Irix optimizer to README.
152
153Library
154
155- Fix a bug in urllib.basejoin("http://host", "../file.html") which
156 omitted the slash between host and file.html.
157
158- The mailbox module's _Mailbox class contained a completely broken
159 and undocumented seek() method. Ripped it out.
160
161- Fixed a bunch of typos in various library modules (urllib2, smtpd,
162 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
163
164- Fixed a few last-minute bugs in unittest.
165
166Extensions
167
168- Reverted the patch to the OpenSSL code in socketmodule.c to support
169 RAND_status() and the EGD, and the subsequent patch that tried to
170 fix it for pre-0.9.5 versions; the problem with the patch is that on
171 some systems it issues a warning whenever socket is imported, and
172 that's unacceptable.
173
174Tests
175
176- Fixed the pickle tests to work with "import test.test_pickle".
177
178- Tweaked test_locale.py to actually run the test Windows.
179
180- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
181 not "wb" (which is not a valid mode at all).
182
183- Fix pstats browser crashes. Import readline if it exists to make
184 the user interface nicer.
185
186- Add "import thread" to the top of test modules that import the
187 threading module (test_asynchat and test_threadedtempfile). This
188 prevents test failures caused by a broken threading module resulting
189 from a previously caught failed import.
190
191- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
192 needed on some platforms (e.g. Solaris 8) when the tests are run
193 twice in succession.
194
195- Skip rather than fail test_sunaudiodev if no audio device is found.
196
197
198What's New in Python 2.1c1?
199===========================
200
201This list was significantly updated when 2.1c2 was released; the 2.1c1
202release didn't mention most changes that were actually part of 2.1c1:
203
204Legal
205
206- Copyright was assigned to the Python Software Foundation (PSF) and a
207 PSF license (very similar to the CNRI license) was added.
208
209- The CNRI copyright notice was updated to include 2001.
210
211Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000212
Guido van Rossumc9932722001-04-12 02:31:27 +0000213- After a public outcry, assignment to __debug__ is no longer illegal;
214 instead, a warning is issued. It will become illegal in 2.2.
215
Guido van Rossum5b08f132001-04-16 02:05:23 +0000216- Fixed a core dump with "%#x" % 0, and changed the semantics so that
217 "%#x" now always prepends "0x", even if the value is zero.
218
219- Fixed some nits in the bytecode compiler.
220
221- Fixed core dumps when calling certain kinds of non-functions.
222
223- Fixed various core dumps caused by reference count bugs.
224
225Build and Ports
226
227- Use INSTALL_SCRIPT to install script files.
228
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000229- New port: SCO Unixware 7, by Billy G. Allie.
230
Guido van Rossum5b08f132001-04-16 02:05:23 +0000231- Updated RISCOS port.
232
233- Updated BeOS port and notes.
234
235- Various other porting problems resolved.
236
237Library
238
239- The TERMIOS and SOCKET modules are now truly obsolete and
240 unnecessary. Their symbols are incorporated in the termios and
241 socket modules.
242
243- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
244 better tests for pickling.
245
246- threading: make Condition.wait() robust against KeyboardInterrupt.
247
248- zipfile: add support to zipfile to support opening an archive
249 represented by an open file rather than a file name. Fix bug where
250 the archive was not properly closed. Fixed a bug in this bugfix
251 where flush() was called for a read-only file.
252
253- imputil: added an uninstall() method to the ImportManager.
254
255- Canvas: fixed bugs in lower() and tkraise() methods.
256
257- SocketServer: API change (added overridable close_request() method)
258 so that the TCP server can explicitly close the request.
259
260- pstats: Eric Raymond added a simple interactive statistics browser,
261 invoked when the module is run as a script.
262
263- locale: fixed a problem in format().
264
265- webbrowser: made it work when the BROWSER environment variable has a
266 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
267 KDE 2. Fixed some other nits.
268
269- unittest: changes to allow using a different exception than
270 AssertionError, and added a few more function aliases. Some other
271 small changes.
272
273- urllib, urllib2: fixed redirect problems and a coupleof other nits.
274
275- asynchat: fixed a critical bug in asynchat that slipped through the
276 2.1b2 release. Fixed another rare bug.
277
278- Fix some unqualified except: clauses (always a bad code example).
279
280XML
281
282- pyexpat: new API get_version_string().
283
284- Fixed some minidom bugs.
285
286Extensions
287
288- Fixed a core dump in _weakref. Removed the weakref.mapping()
289 function (it adds nothing to the API).
290
291- Rationalized the use of header files in the readline module, to make
292 it compile (albeit with some warnings) with the very recent readline
293 4.2, without breaking for earlier versions.
294
295- Hopefully fixed a buffering problem in linuxaudiodev.
296
297- Attempted a fix to make the OpenSSL support in the socket module
298 work again with pre-0.9.5 versions of OpenSSL.
299
300Tests
301
302- Added a test case for asynchat and asyncore.
303
304- Removed coupling between tests where one test failing could break
305 another.
306
307Tools
308
309- Ping added an interactive help browser to pydoc, fixed some nits
310 in the rest of the pydoc code, and added some features to his
311 inspect module.
312
313- An updated python-mode.el version 4.1 which integrates Ken
314 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
315 much nicer in XEmacs and Emacs. When stepping through your program
316 with pdb, in either the shell window or the *Python* window, the
317 source file and line will be tracked by an arrow. Very cool!
318
319- IDLE: syntax warnings in interactive mode are changed into errors.
320
321- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000322 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000323
324- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000325
Barry Warsaw11e89c72001-04-11 20:37:57 +0000326
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000327What's New in Python 2.1 beta 2?
328================================
329
Guido van Rossum053ae352001-03-22 14:17:21 +0000330(Unlisted are many fixed bugs, more documentation, etc.)
331
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000332Core language, builtins, and interpreter
333
Guido van Rossum053ae352001-03-22 14:17:21 +0000334- The nested scopes work (enabled by "from __future__ import
335 nested_scopes") is completed; in particular, the future now extends
336 into code executed through exec, eval() and execfile(), and into the
337 interactive interpreter.
338
339- When calling a base class method (e.g. BaseClass.__init__(self)),
340 this is now allowed even if self is not strictly spoken a class
341 instance (e.g. when using metaclasses or the Don Beaudry hook).
342
343- Slice objects are now comparable but not hashable; this prevents
344 dict[:] from being accepted but meaningless.
345
346- Complex division is now calculated using less braindead algorithms.
347 This doesn't change semantics except it's more likely to give useful
348 results in extreme cases. Complex repr() now uses full precision
349 like float repr().
350
351- sgmllib.py now calls handle_decl() for simple <!...> declarations.
352
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000353- It is illegal to assign to the name __debug__, which is set when the
354 interpreter starts. It is effectively a compile-time constant.
355
356- A warning will be issued if a global statement for a variable
357 follows a use or assignment of that variable.
358
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000359Standard library
360
Guido van Rossum053ae352001-03-22 14:17:21 +0000361- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
362 inspired by JUnit), is now part of the standard library. You now
363 have a choice of two testing frameworks: unittest requires you to
364 write testcases as separate code, doctest gathers them from
365 docstrings. Both approaches have their advantages and
366 disadvantages.
367
368- A new module Tix was added, which wraps the Tix extension library
369 for Tk. With that module, it is not necessary to statically link
370 Tix with _tkinter, since Tix will be loaded with Tcl's "package
371 require" command. See Demo/tix/.
372
373- tzparse.py is now obsolete.
374
375- In gzip.py, the seek() and tell() methods are removed -- they were
376 non-functional anyway, and it's better if callers can test for their
377 existence with hasattr().
378
379Python/C API
380
381- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
382 that's already in the dictionary during a PyDict_Next() iteration.
383 This used to fail occasionally when a dictionary resize operation
384 could be triggered that would rehash all the keys. All other
385 modifications to the dictionary are still off-limits during a
386 PyDict_Next() iteration!
387
388- New extended APIs related to passing compiler variables around.
389
390- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
391 implement isinstance() and issubclass().
392
393- Py_BuildValue() now has a "D" conversion to create a Python complex
394 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000395
Fred Drake4e262a92001-03-22 18:26:47 +0000396- Extensions types which support weak references must now set the
397 field allocated for the weak reference machinery to NULL themselves;
398 this is done to avoid the cost of checking each object for having a
399 weakly referencable type in PyObject_INIT(), since most types are
400 not weakly referencable.
401
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000402- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
403 free variables and cell variables to and from the frame's f_locals.
404
405- Variants of several functions defined in pythonrun.h have been added
406 to support the nested_scopes future statement. The variants all end
407 in Flags and take an extra argument, a PyCompilerFlags *; examples:
408 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
409 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000410 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000411
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000412Distutils
413
414- the sdist command now writes a PKG-INFO file, as described in PEP 241,
415 into the release tree.
416
Tim Peters0e57abf2001-05-02 07:39:38 +0000417- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000418 (an uninstaller, more customization of the installer's display)
419
420- from Jack Jansen: added Mac-specific code to generate a dialog for
421 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000422 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000423 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000424
425- added 'platforms' and 'keywords' to the set of metadata that can be
426 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000427
428- applied patches from Jason Tishler to make the compiler class work with
429 Cygwin.
430
431
Tim Peters2fe289a2001-03-01 22:19:38 +0000432What's New in Python 2.1 beta 1?
433================================
Tim Petersd66595f2001-02-04 03:09:53 +0000434
435Core language, builtins, and interpreter
436
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000437- Following an outcry from the community about the amount of code
438 broken by the nested scopes feature introduced in 2.1a2, we decided
439 to make this feature optional, and to wait until Python 2.2 (or at
440 least 6 months) to make it standard. The option can be enabled on a
441 per-module basis by adding "from __future__ import nested_scopes" at
442 the beginning of a module (before any other statements, but after
443 comments and an optional docstring). See PEP 236 (Back to the
444 __future__) for a description of the __future__ statement. PEP 227
445 (Statically Nested Scopes) has been updated to reflect this change,
446 and to clarify the semantics in a number of endcases.
447
448- The nested scopes code, when enabled, has been hardened, and most
449 bugs and memory leaks in it have been fixed.
450
451- Compile-time warnings are now generated for a number of conditions
452 that will break or change in meaning when nested scopes are enabled:
453
454 - Using "from...import *" or "exec" without in-clause in a function
455 scope that also defines a lambda or nested function with one or
456 more free (non-local) variables. The presence of the import* or
457 bare exec makes it impossible for the compiler to determine the
458 exact set of local variables in the outer scope, which makes it
459 impossible to determine the bindings for free variables in the
460 inner scope. To avoid the warning about import *, change it into
461 an import of explicitly name object, or move the import* statement
462 to the global scope; to avoid the warning about bare exec, use
463 exec...in... (a good idea anyway -- there's a possibility that
464 bare exec will be deprecated in the future).
465
466 - Use of a global variable in a nested scope with the same name as a
467 local variable in a surrounding scope. This will change in
468 meaning with nested scopes: the name in the inner scope will
469 reference the variable in the outer scope rather than the global
470 of the same name. To avoid the warning, either rename the outer
471 variable, or use a global statement in the inner function.
472
Neil Schemenauera35c6882001-02-27 04:45:05 +0000473- An optional object allocator has been included. This allocator is
474 optimized for Python objects and should be faster and use less memory
475 than the standard system allocator. It is not enabled by default
476 because of possible thread safety problems. The allocator is only
477 protected by the Python interpreter lock and it is possible that some
478 extension modules require a thread safe allocator. The object
479 allocator can be enabled by providing the "--with-pymalloc" option to
480 configure.
481
Tim Petersd66595f2001-02-04 03:09:53 +0000482Standard library
483
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000484- pyexpat now detects the expat version if expat.h defines it. A
485 number of additional handlers are provided, which are only available
486 since expat 1.95. In addition, the methods SetParamEntityParsing and
487 GetInputContext of Parser objects are available with 1.95.x
488 only. Parser objects now provide the ordered_attributes and
489 specified_attributes attributes. A new module expat.model was added,
490 which offers a number of additional constants if 1.95.x is used.
491
492- xml.dom offers the new functions registerDOMImplementation and
493 getDOMImplementation.
494
495- xml.dom.minidom offers a toprettyxml method. A number of DOM
496 conformance issues have been resolved. In particular, Element now
497 has an hasAttributes method, and the handling of namespaces was
498 improved.
499
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000500- Ka-Ping Yee contributed two new modules: inspect.py, a module for
501 getting information about live Python code, and pydoc.py, a module
502 for interactively converting docstrings to HTML or text.
503 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000504 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000505 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
506 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000507
Tim Peters1eff7962001-03-01 02:31:33 +0000508- New library module difflib.py, primarily packaging the SequenceMatcher
509 class at the heart of the popular ndiff.py file-comparison tool.
510
511- doctest.py (a framework for verifying Python code examples in docstrings)
512 is now part of the std library.
513
Tim Petersd66595f2001-02-04 03:09:53 +0000514Windows changes
515
Guido van Rossume3955a82001-03-02 14:05:59 +0000516- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
517 small GUI that lets you browse the module docstrings using your
518 default web browser.
519
Tim Peters1eff7962001-03-01 02:31:33 +0000520- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
521 Platforms) is implemented. See
522
523 http://python.sourceforge.net/peps/pep-0235.html
524
525 for full details, especially the "Current Lower-Left Semantics" section.
526 The new Windows import rules are simpler than before:
527
528 A. If the PYTHONCASEOK environment variable exists, same as
529 before: silently accept the first case-insensitive match of any
530 kind; raise ImportError if none found.
531
532 B. Else search sys.path for the first case-sensitive match; raise
533 ImportError if none found.
534
535 The same rules have been implented on other platforms with case-
536 insensitive but case-preserving filesystems too (including Cygwin, and
537 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000538
Tim Peters25a9ce32001-02-19 07:06:36 +0000539- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
540 what it's supposed to do (and does do under NT and 2000) via direct
541 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000542 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000543 all Win9x systems before.
544
Tim Peters1eff7962001-03-01 02:31:33 +0000545- Build: Subproject _test (effectively) renamed to _testcapi.
546
Tim Peters2fe289a2001-03-01 22:19:38 +0000547New platforms
548
549- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
550 Thanks to Steven Majewski!
551
552- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
553 Tishler!
554
Guido van Rossum9089b272001-03-02 06:49:50 +0000555- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
556 Schwertberger! See RISCOS/README for more information -- it seems
557 that because of the bizarre filename conventions on RISCOS, no port
558 to that platform is easy. Note that the new variable os.endsep is
559 silently supported in order to make life easier on this platform,
560 but we don't advertise it because it's not worth for most folks to
561 care about RISCOS portability.
562
Tim Peters25a9ce32001-02-19 07:06:36 +0000563
Tim Petersd7b5e882001-01-25 03:36:26 +0000564What's New in Python 2.1 alpha 2?
565=================================
Tim Peters40ead762001-01-27 05:35:26 +0000566
Tim Petersd7b5e882001-01-25 03:36:26 +0000567Core language, builtins, and interpreter
568
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000569- Scopes nest. If a name is used in a function or class, but is not
570 local, the definition in the nearest enclosing function scope will
571 be used. One consequence of this change is that lambda statements
572 could reference variables in the namespaces where the lambda is
573 defined. In some unusual cases, this change will break code.
574
575 In all previous version of Python, names were resolved in exactly
576 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000577 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000578 function A is defined within a function B, the names bound in B are
579 not visible in A. The new rules make names bound in B visible in A,
580 unless A contains a name binding that hides the binding in B.
581
582 Section 4.1 of the reference manual describes the new scoping rules
583 in detail. The test script in Lib/test/test_scope.py demonstrates
584 some of the effects of the change.
585
586 The new rules will cause existing code to break if it defines nested
587 functions where an outer function has local variables with the same
588 name as globals or builtins used by the inner function. Example:
589
590 def munge(str):
591 def helper(x):
592 return str(x)
593 if type(str) != type(''):
594 str = helper(str)
595 return str.strip()
596
597 Under the old rules, the name str in helper() is bound to the
598 builtin function str(). Under the new rules, it will be bound to
599 the argument named str and an error will occur when helper() is
600 called.
601
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000602- The compiler will report a SyntaxError if "from ... import *" occurs
603 in a function or class scope. The language reference has documented
604 that this case is illegal, but the compiler never checked for it.
605 The recent introduction of nested scope makes the meaning of this
606 form of name binding ambiguous. In a future release, the compiler
607 may allow this form when there is no possibility of ambiguity.
608
Tim Peters40ead762001-01-27 05:35:26 +0000609- repr(string) is easier to read, now using hex escapes instead of octal,
610 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
611
612 >>> "\texample \r\n" + chr(0) + chr(255)
613 '\texample \r\n\x00\xff' # in 2.1
614 '\011example \015\012\000\377' # in 2.0
615
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000616- Functions are now compared and hashed by identity, not by value, since
617 the func_code attribute is writable.
618
Fred Drakefb9d7122001-02-01 20:00:40 +0000619- Weak references (PEP 205) have been added. This involves a few
620 changes in the core, an extension module (_weakref), and a Python
621 module (weakref). The weakref module is the public interface. It
622 includes support for "explicit" weak references, proxy objects, and
623 mappings with weakly held values.
624
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000625- A 'continue' statement can now appear in a try block within the body
626 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000627 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000628
Tim Petersd7b5e882001-01-25 03:36:26 +0000629Standard library
630
Barry Warsaw30dbd142001-01-31 22:14:01 +0000631- mailbox.py now has a new class, PortableUnixMailbox which is
632 identical to UnixMailbox but uses a more portable scheme for
633 determining From_ separators. Also, the constructors for all the
634 classes in this module have a new optional `factory' argument, which
635 is a callable used when new message classes must be instantiated by
636 the next() method.
637
Tim Petersd7b5e882001-01-25 03:36:26 +0000638- random.py is now self-contained, and offers all the functionality of
639 the now-deprecated whrandom.py. See the docs for details. random.py
640 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000641 and restoring the internal state of the generator; and jumpahead(n),
642 for quickly forcing the internal state to be the same as if n calls to
643 random() had been made. The latter is particularly useful for multi-
644 threaded programs, creating one instance of the random.Random() class for
645 each thread, then using .jumpahead() to force each instance to use a
646 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000647
Tim Peters0de88fc2001-02-01 04:59:18 +0000648- random.py's seed() function is new. For bit-for-bit compatibility with
649 prior releases, use the whseed function instead. The new seed function
650 addresses two problems: (1) The old function couldn't produce more than
651 about 2**24 distinct internal states; the new one about 2**45 (the best
652 that can be done in the Wichmann-Hill generator). (2) The old function
653 sometimes produced identical internal states when passed distinct
654 integers, and there was no simple way to predict when that would happen;
655 the new one guarantees to produce distinct internal states for all
656 arguments in [0, 27814431486576L).
657
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000658- The socket module now supports raw packets on Linux. The socket
659 family is AF_PACKET.
660
Tim Peters9ea17ac2001-02-02 05:57:15 +0000661- test_capi.py is a start at running tests of the Python C API. The tests
662 are implemented by the new Modules/_testmodule.c.
663
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000664- A new extension module, _symtable, provides provisional access to the
665 internal symbol table used by the Python compiler. A higher-level
666 interface will be added on top of _symtable in a future release.
667
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000668- Removed the obsolete soundex module.
669
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000670- xml.dom.minidom now uses the standard DOM exceptions. Node supports
671 the isSameNode method; NamedNodeMap the get method.
672
673- xml.sax.expatreader supports the lexical handler property; it
674 generates comment, startCDATA, and endCDATA events.
675
Tim Petersee826f82001-01-31 19:39:44 +0000676Windows changes
677
678- Build procedure: the zlib project is built in a different way that
679 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000680 the zlib binary used. See PCbuild\readme.txt for details. Your old
681 zlib-related directories can be deleted; you'll need to download fresh
682 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000683
Tim Peters9ea17ac2001-02-02 05:57:15 +0000684- Build: New subproject _test for the benefit of test_capi.py (see above).
685
Tim Petersb16c56f2001-02-02 21:24:51 +0000686- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
687 interface to some Python compiler internals).
688
689- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000690 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000691
Tim Petersa3a3a032000-11-30 05:22:44 +0000692What's New in Python 2.1 alpha 1?
693=================================
694
695Core language, builtins, and interpreter
696
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000697- There is a new Unicode companion to the PyObject_Str() API
698 called PyObject_Unicode(). It behaves in the same way as the
699 former, but assures that the returned value is an Unicode object
700 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000701
Guido van Rossumf98eda02001-01-17 15:54:45 +0000702- The comparison operators support "rich comparison overloading" (PEP
703 207). C extension types can provide a rich comparison function in
704 the new tp_richcompare slot in the type object. The cmp() function
705 and the C function PyObject_Compare() first try the new rich
706 comparison operators before trying the old 3-way comparison. There
707 is also a new C API PyObject_RichCompare() (which also falls back on
708 the old 3-way comparison, but does not constrain the outcome of the
709 rich comparison to a Boolean result).
710
711 The rich comparison function takes two objects (at least one of
712 which is guaranteed to have the type that provided the function) and
713 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
714 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
715 object, which may be NotImplemented (in which case the tp_compare
716 slot function is used as a fallback, if defined).
717
718 Classes can overload individual comparison operators by defining one
719 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000720 __ge__. There are no explicit "reflected argument" versions of
721 these; instead, __lt__ and __gt__ are each other's reflection,
722 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
723 reflection (similar at the C level). No other implications are
724 made; in particular, Python does not assume that == is the Boolean
725 inverse of !=, or that < is the Boolean inverse of >=. This makes
726 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000727
728 Classes or types that want to implement (in)equality tests but not
729 the ordering operators (i.e. unordered types) should implement ==
730 and !=, and raise an error for the ordering operators.
731
Guido van Rossuma88479f2001-01-18 14:28:08 +0000732 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000733 Boolean; e.g. a matrix type might want to return a matrix of bits
734 for A < B, giving elementwise comparisons. Such types should ensure
735 that any interpretation of their value in a Boolean context raises
736 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
737 at the C level) to always raise an exception.
738
Guido van Rossuma88479f2001-01-18 14:28:08 +0000739- Complex numbers use rich comparisons to define == and != but raise
740 an exception for <, <=, > and >=. Unfortunately, this also means
741 that cmp() of two complex numbers raises an exception when the two
742 numbers differ. Since it is not mathematically meaningful to compare
743 complex numbers except for equality, I hope that this doesn't break
744 too much code.
745
Tim Peters3389f192001-02-18 08:48:49 +0000746- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000747 not defined by the language, other than that it's arbitrary but
748 consistent (see the Reference Manual). An implementation detail changed
749 in 2.1a1 such that None now compares less than any other object. Code
750 relying on this new behavior (like code that relied on the previous
751 behavior) does so at its own risk.
752
Barry Warsaw573b5412001-01-15 20:43:18 +0000753- Functions and methods now support getting and setting arbitrarily
754 named attributes (PEP 232). Functions have a new __dict__
755 (a.k.a. func_dict) which hold the function attributes. Methods get
756 and set attributes on their underlying im_func. It is a TypeError
757 to set an attribute on a bound method.
758
Guido van Rossum051e3352001-01-15 19:11:10 +0000759- The xrange() object implementation has been improved so that
760 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
761 limitation that in this case len(xrange(sys.maxint)) can't be
762 calculated, but the common idiom "for i in xrange(sys.maxint)" will
763 work fine as long as the index i doesn't actually reach 2**31.
764 (Python uses regular ints for sequence and string indices; fixing
765 that is much more work.)
766
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000767- Two changes to from...import:
768
Guido van Rossumba381232001-02-03 15:06:40 +0000769 1) "from M import X" now works even if (after loading module M)
770 sys.modules['M'] is not a real module; it's basically a getattr()
771 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000772
773 2) "from M import *" now looks for M.__all__ to decide which names to
774 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
775 filters out names starting with '_' as before. Whether or not
776 __all__ exists, there's no restriction on the type of M.
777
Guido van Rossumf61f1662001-01-10 20:13:55 +0000778- File objects have a new method, xreadlines(). This is the fastest
779 way to iterate over all lines in a file:
780
781 for line in file.xreadlines():
782 ...do something to line...
783
784 See the xreadlines module (mentioned below) for how to do this for
785 other file-like objects.
786
787- Even if you don't use file.xreadlines(), you may expect a speedup on
788 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000789 quite a bit in platform-specific ways: on systems (like Linux) that
790 support flockfile(), getc_unlocked(), and funlockfile(), those are
791 used by default. On systems (like Windows) without getc_unlocked(),
792 a complicated (but still thread-safe) method using fgets() is used by
793 default.
794
Tim Petersd52269b2001-01-25 06:23:18 +0000795 You can force use of the fgets() method by #define'ing
796 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000797 getc_unlocked()).
798
Tim Petersd52269b2001-01-25 06:23:18 +0000799 You can force fgets() not to be used by #define'ing
800 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000801 test_bufio.py fails -- and let us know if it does!).
802
803- In addition, the fileinput module, while still slower than the other
804 methods on most platforms, has been sped up too, by using
805 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000806
807- Support for run-time warnings has been added, including a new
808 command line option (-W) to specify the disposition of warnings.
809 See the description of the warnings module below.
810
811- Extensive changes have been made to the coercion code. This mostly
812 affects extension modules (which can now implement mixed-type
813 numerical operators without having to use coercion), but
814 occasionally, in boundary cases the coercion semantics have changed
815 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000816 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000817 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000818 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000819
Guido van Rossumf98eda02001-01-17 15:54:45 +0000820- In connection with the coercion changes, a new built-in singleton
821 object, NotImplemented is defined. This can be returned for
822 operations that wish to indicate they are not implemented for a
823 particular combination of arguments. From C, this is
824 Py_NotImplemented.
825
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000826- The interpreter accepts now bytecode files on the command line even
827 if they do not have a .pyc or .pyo extension. On Linux, after executing
828
Martin v. Löwise214baa2001-02-04 22:37:56 +0000829import imp,sys,string
830magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
831reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
832open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000833
834 any byte code file can be used as an executable (i.e. as an argument
835 to execve(2)).
836
Tim Peters9940b802000-12-01 07:59:35 +0000837- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000838 character. In 1.6 and earlier, they never produced a sign,
839 and raised an error if the value of the long was too large
840 to fit in a Python int. In 2.0, they produced a sign if and
841 only if too large to fit in an int. This was inconsistent
842 across platforms (because the size of an int varies across
843 platforms), and inconsistent with hex() and oct(). Example:
844
845 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000846 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000847 'ffffffbe' # in 2.0 and before, on 32-bit machines
848 >>> hex(-0x42L)
849 '-0x42L' # in all versions of Python
850
Tim Peters9940b802000-12-01 07:59:35 +0000851 The behavior of %d formats for negative Python longs remains
852 the same as in 2.0 (although in 1.6 and before, they raised
853 an error if the long didn't fit in a Python int).
854
855 %u formats don't make sense for Python longs, but are allowed
856 and treated the same as %d in 2.1. In 2.0, a negative long
857 formatted via %u produced a sign if and only if too large to
858 fit in an int. In 1.6 and earlier, a negative long formatted
859 via %u raised an error if it was too big to fit in an int.
860
Guido van Rossum3661d392000-12-12 22:10:31 +0000861- Dictionary objects have an odd new method, popitem(). This removes
862 an arbitrary item from the dictionary and returns it (in the form of
863 a (key, value) pair). This can be useful for algorithms that use a
864 dictionary as a bag of "to do" items and repeatedly need to pick one
865 item. Such algorithms normally end up running in quadratic time;
866 using popitem() they can usually be made to run in linear time.
867
Tim Peters36cdad12000-12-29 02:06:45 +0000868Standard library
869
Thomas Woutersfe385252001-01-19 23:16:56 +0000870- In the time module, the time argument to the functions strftime,
871 localtime, gmtime, asctime and ctime is now optional, defaulting to
872 the current time (in the local timezone).
873
Guido van Rossumda91f222001-01-15 16:36:08 +0000874- The ftplib module now defaults to passive mode, which is deemed a
875 more useful default given that clients are often inside firewalls
876 these days. Note that this could break if ftplib is used to connect
877 to a *server* that is inside a firewall, from outside; this is
878 expected to be a very rare situation. To fix that, you can call
879 ftp.set_pasv(0).
880
Martin v. Löwis10a27872001-01-13 09:54:41 +0000881- The module site now treats .pth files not only for path configuration,
882 but also supports extensions to the initialization code: Lines starting
883 with import are executed.
884
Guido van Rossumf61f1662001-01-10 20:13:55 +0000885- There's a new module, warnings, which implements a mechanism for
886 issuing and filtering warnings. There are some new built-in
887 exceptions that serve as warning categories, and a new command line
888 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
889 turns warnings into errors). warnings.warn(message[, category])
890 issues a warning message; this can also be called from C as
891 PyErr_Warn(category, message).
892
893- A new module xreadlines was added. This exports a single factory
894 function, xreadlines(). The intention is that this code is the
895 absolutely fastest way to iterate over all lines in an open
896 file(-like) object:
897
898 import xreadlines
899 for line in xreadlines.xreadlines(file):
900 ...do something to line...
901
902 This is equivalent to the previous the speed record holder using
903 file.readlines(sizehint). Note that if file is a real file object
904 (as opposed to a file-like object), this is equivalent:
905
906 for line in file.xreadlines():
907 ...do something to line...
908
Tim Peters36cdad12000-12-29 02:06:45 +0000909- The bisect module has new functions bisect_left, insort_left,
910 bisect_right and insort_right. The old names bisect and insort
911 are now aliases for bisect_right and insort_right. XXX_right
912 and XXX_left methods differ in what happens when the new element
913 compares equal to one or more elements already in the list: the
914 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000915 right. Code that doesn't care where equal elements end up should
916 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000917
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000918- The new curses.panel module wraps the panel library that forms part
919 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
920
Guido van Rossumf61f1662001-01-10 20:13:55 +0000921- The SocketServer module now sets the allow_reuse_address flag by
922 default in the TCPServer class.
923
924- A new function, sys._getframe(), returns the stack frame pointer of
925 the caller. This is intended only as a building block for
926 higher-level mechanisms such as string interpolation.
927
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000928- The pyexpat module supports a number of new handlers, which are
929 available only in expat 1.2. If invocation of a callback fails, it
930 will report an additional frame in the traceback. Parser objects
931 participate now in garbage collection. If expat reports an unknown
932 encoding, pyexpat will try to use a Python codec; that works only
933 for single-byte charsets. The parser type objects is exposed as
934 XMLParserObject.
935
936- xml.dom now offers standard definitions for symbolic node type and
937 exception code constants, and a hierarchy of DOM exceptions. minidom
938 was adjusted to use them.
939
940- The conformance of xml.dom.minidom to the DOM specification was
941 improved. It detects a number of additional error cases; the
942 previous/next relationship works even when the tree is modified;
943 Node supports the normalize() method; NamedNodeMap, DocumentType and
944 DOMImplementation classes were added; Element supports the
945 hasAttribute and hasAttributeNS methods; and Text supports the splitText
946 method.
947
Guido van Rossumf61f1662001-01-10 20:13:55 +0000948Build issues
949
Guido van Rossum1e33bdc2001-01-23 03:17:00 +0000950- For Unix (and Unix-compatible) builds, configuration and building of
951 extension modules is now greatly automated. Rather than having to
952 edit the Modules/Setup file to indicate which modules should be
953 built and where their include files and libraries are, a
954 distutils-based setup.py script now takes care of building most
955 extension modules. All extension modules built this way are built
956 as shared libraries. Only a few modules that must be linked
957 statically are still listed in the Setup file; you won't need to
958 edit their configuration.
959
960- Python should now build out of the box on Cygwin. If it doesn't,
961 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000962
963- Python now always uses its own (renamed) implementation of getopt()
964 -- there's too much variation among C library getopt()
965 implementations.
966
967- C++ compilers are better supported; the CXX macro is always set to a
968 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +0000969
Tim Petersd92dfe02000-12-12 01:18:41 +0000970Windows changes
971
972- select module: By default under Windows, a select() call
973 can specify no more than 64 sockets. Python now boosts
974 this Microsoft default to 512. If you need even more than
975 that, see the MS docs (you'll need to #define FD_SETSIZE
976 and recompile Python from source).
977
Guido van Rossumf61f1662001-01-10 20:13:55 +0000978- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
979 subdirectory is no more!
980
Tim Petersa3a3a032000-11-30 05:22:44 +0000981
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000982What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +0000983=========================
Guido van Rossum61000331997-08-15 04:39:58 +0000984
Guido van Rossum8ed602b2000-09-01 22:34:33 +0000985Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000986changes are in the file HISTORY. If you are making the jump directly
987from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
988HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +0000989
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000990Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
991the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
992http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +0000993
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000994--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +0000995
996======================================================================
997
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000998What's new in 2.0 (since release candidate 1)?
999==============================================
1000
1001Standard library
1002
1003- The copy_reg module was modified to clarify its intended use: to
1004 register pickle support for extension types, not for classes.
1005 pickle() will raise a TypeError if it is passed a class.
1006
1007- Fixed a bug in gettext's "normalize and expand" code that prevented
1008 it from finding an existing .mo file.
1009
1010- Restored support for HTTP/0.9 servers in httplib.
1011
Tim Peters989b7b92000-10-16 20:24:53 +00001012- The math module was changed to stop raising OverflowError in case of
1013 underflow, and return 0 instead in underflow cases. Whether Python
1014 used to raise OverflowError in case of underflow was platform-
1015 dependent (it did when the platform math library set errno to ERANGE
1016 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001017
1018- Fixed a bug in StringIO that occurred when the file position was not
1019 at the end of the file and write() was called with enough data to
1020 extend past the end of the file.
1021
1022- Fixed a bug that caused Tkinter error messages to get lost on
1023 Windows. The bug was fixed by replacing direct use of
1024 interp->result with Tcl_GetStringResult(interp).
1025
1026- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1027 redirect response.
1028
1029- Several changes were made to distutils: Some debugging code was
1030 removed from util. Fixed the installer used when an external zip
1031 program (like WinZip) is not found; the source code for this
1032 installer is in Misc/distutils. check_lib() was modified to behave
1033 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1034 test for whether installed modules are on sys.path was changed to
1035 use both normcase() and normpath().
1036
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001037- Several minor bugs were fixed in the xml package (the minidom,
1038 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001039
1040- The regression test driver (regrtest.py) behavior when invoked with
1041 -l changed: It now reports a count of objects that are recognized as
1042 garbage but not freed by the garbage collector.
1043
Tim Peters989b7b92000-10-16 20:24:53 +00001044- The regression test for the math module was changed to test
1045 exceptional behavior when the test is run in verbose mode. Python
1046 cannot yet guarantee consistent exception behavior across platforms,
1047 so the exception part of test_math is run only in verbose mode, and
1048 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001049
1050Internals
1051
1052- PyOS_CheckStack() has been disabled on Win64, where it caused
1053 test_sre to fail.
1054
1055Build issues
1056
1057- Changed compiler flags, so that gcc is always invoked with -Wall and
1058 -Wstrict-prototypes. Users compiling Python with GCC should see
1059 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001060 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001061 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001062
Tim Petersa3a3a032000-11-30 05:22:44 +00001063- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001064
1065Tools and other miscellany
1066
1067- The compiler in Tools/compiler was updated to support the new
1068 language features introduced in 2.0: extended print statement, list
1069 comprehensions, and augmented assignments. The new compiler should
1070 also be backwards compatible with Python 1.5.2; the compiler will
1071 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001072 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001073
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001074What's new in 2.0 release candidate 1 (since beta 2)?
1075=====================================================
1076
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001077What is release candidate 1?
1078
1079We believe that release candidate 1 will fix all known bugs that we
1080intend to fix for the 2.0 final release. This release should be a bit
1081more stable than the previous betas. We would like to see even more
1082widespread testing before the final release, so we are producing this
1083release candidate. The final release will be exactly the same unless
1084any show-stopping (or brown bag) bugs are found by testers of the
1085release candidate.
1086
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001087All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001088to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001089
1090Core language, builtins, and interpreter
1091
1092- A bug that caused crashes when __coerce__ was used with augmented
1093 assignment, e.g. +=, was fixed.
1094
1095- Raise ZeroDivisionError when raising zero to a negative number,
1096 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1097 power operator and the result of math.pow(0.0, -2.0) will vary by
1098 platform. On Linux, it raises a ValueError.
1099
1100- A bug in Unicode string interpolation was fixed that occasionally
1101 caused errors with formats including "%%". For example, the
1102 following expression "%% %s" % u"abc" no longer raises a TypeError.
1103
1104- Compilation of deeply nested expressions raises MemoryError instead
1105 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1106
1107- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1108 rendering them useless. They are now written in binary mode again.
1109
1110Standard library
1111
1112- Keyword arguments are now accepted for most pattern and match object
1113 methods in SRE, the standard regular expression engine.
1114
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001115- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001116 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001117
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001118- Several bugs in the Unicode handling and error handling in _tkinter
1119 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001120
1121- Fix memory management errors in Merge() and Tkapp_Call() routines.
1122
1123- Several changes were made to cStringIO to make it compatible with
1124 the file-like object interface and with StringIO. If operations are
1125 performed on a closed object, an exception is raised. The truncate
1126 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001127 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001128
1129- There were many changes made to the linuxaudiodev module and its
1130 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001131 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001132
1133 Note that this module is named poorly, because it should work
1134 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001135 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001136
1137 The module now raises exceptions when errors occur instead of
1138 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1139 audio) and defines a getptr() method that calls the
1140 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1141
1142- The library_version attribute, introduced in an earlier beta, was
1143 removed because it can not be supported with early versions of the C
1144 readline library, which provides no way to determine the version at
1145 compile-time.
1146
1147- The binascii module is now enabled on Win64.
1148
Tim Peters46446d62000-10-09 21:19:31 +00001149- tokenize.py no longer suffers "recursion depth" errors when parsing
1150 programs with very long string literals.
1151
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001152Internals
1153
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001154- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001155 which is called when the interpreter starts up to determine where
1156 the standard library is installed. These vulnerabilities affect all
1157 previous versions of Python and can be exploited by setting very
1158 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1159 setuid Python script, although use of the wrapper in
1160 Misc/setuid-prog.c will eliminate the vulnerability.
1161
1162- Fixed garbage collection bugs in instance creation that were
1163 triggered when errors occurred during initialization. The solution,
1164 applied in cPickle and in PyInstance_New(), is to call
1165 PyObject_GC_Init() after the initialization of the object's
1166 container attributes is complete.
1167
1168- pyexpat adds definitions of PyModule_AddStringConstant and
1169 PyModule_AddObject if the Python version is less than 2.0, which
1170 provides compatibility with PyXML on Python 1.5.2.
1171
1172- If the platform has a bogus definition for LONG_BIT (the number of
1173 bits in a long), an error will be reported at compile time.
1174
1175- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1176 collection crashes and possibly other, unreported crashes.
1177
1178- Fixed a memory leak in _PyUnicode_Fini().
1179
1180Build issues
1181
1182- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001183 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001184 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001185
1186- The mmap.PAGESIZE constant is now initialized using sysconf when
1187 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1188
1189- The md5 file should now compile on all platforms.
1190
1191- The select module now compiles on platforms that do not define
1192 POLLRDNORM and related constants.
1193
1194- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001195 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001196
Jeremy Hylton10921202000-10-09 18:34:12 +00001197- BeOS: A number of changes were made to the build and installation
1198 process. ar-fake now operates on a directory of object files.
1199 dl_export.h is gone, and its macros now appear on the mwcc command
1200 line during build on PPC BeOS.
1201
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001202- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001203 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001204
1205- Cygwin: Support for shared libraries, Tkinter, and sockets.
1206
1207- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1208
1209Tools and other miscellany
1210
1211- Removed debugging prints from main used with freeze.
1212
Tim Peters46446d62000-10-09 21:19:31 +00001213- IDLE auto-indent no longer crashes when it encounters Unicode
1214 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001215
1216What's new in 2.0 beta 2 (since beta 1)?
1217========================================
1218
1219Core language, builtins, and interpreter
1220
Tim Peters482c0212000-09-26 06:33:09 +00001221- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001222 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001223
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001224- Add -h and -V command line options to print the usage message and
1225 Python version number and exit immediately.
1226
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001227- eval() and exec accept Unicode objects as code parameters.
1228
1229- getattr() and setattr() now also accept Unicode objects for the
1230 attribute name, which are converted to strings using the default
1231 encoding before lookup.
1232
1233- Multiplication on string and Unicode now does proper bounds
1234 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1235 string is too long."
1236
1237- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001238 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001239
Jeremy Hylton1b618592000-09-26 05:32:36 +00001240
1241Standard library and extensions
1242
Guido van Rossum5b08f132001-04-16 02:05:23 +00001243- socket module: the OpenSSL code now adds support for RAND_status()
1244 and EGD (Entropy Gathering Device).
1245
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001246- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001247 argument checking; it still takes no arguments.
1248
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001249- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001250
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001251- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001252
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001253- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001254
1255- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001256 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001257
1258- copy: Copy Unicode objects atomically.
1259
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001260- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001261
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001262- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001263
Fred Drake67233bc2000-09-26 16:40:27 +00001264- dbm: Add get() and setdefault() methods to dbm object. Add constant
1265 `library' to module that names the library used. Added doc strings
1266 and method names to error messages. Uses configure to determine
1267 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1268 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001269
1270- distutils: Update to version 0.9.3.
1271
1272- dl: Add several dl.RTLD_ constants.
1273
1274- fpectl: Now supported on FreeBSD.
1275
1276- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1277 found by the collector will be saved in gc.garbage. This is useful
1278 for debugging a program that creates reference cycles.
1279
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001280- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001281 of HTTP class. Do not close socket on zero-length response. Do not
1282 crash when server sends invalid content-length header.
1283
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001284- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001285
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001286- marshal: When reading a short, sign-extend on platforms where shorts
1287 are bigger than 16 bits. When reading a long, repair the unportable
1288 sign extension that was being done for 64-bit machines. (It assumed
1289 that signed right shift sign-extends.)
1290
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001291- operator: Add contains(), invert(), __invert__() as aliases for
1292 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001293
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001294- os: Add support for popen2() and popen3() on all platforms where
1295 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001296
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001297- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001298 clicking on a file in Explorer (or passing the file name to the
1299 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001300
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001301- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001302 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001303
1304- pickle: Now raises ValueError when an invalid pickle that contains
1305 a non-string repr where a string repr was expected. This behavior
1306 matches cPickle.
1307
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001308- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001309
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001310- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001311
1312- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001313 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001314 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001315
1316- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001317 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001318
1319- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001320 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001321 few cycles during startup since the first call to
1322 setdefaultencoding() will initialize the codec registry and the
1323 encodings package.
1324
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001325- socket: Support for size hint in readlines() method of object returned
1326 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001327
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001328- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001329 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001330 is followed by whitespace.
1331
Tim Petersa3a3a032000-11-30 05:22:44 +00001332- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001333
1334- struct: Check ranges for bytes and shorts.
1335
1336- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001337 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001338
1339- Tkinter: Image objects are now guaranteed to have unique ids. Set
1340 event.delta to zero if Tk version doesn't support mousewheel.
1341 Removed some debugging prints.
1342
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001343- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001344
Fred Drake67233bc2000-09-26 16:40:27 +00001345- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001346 which works around a bug in Norton AntiVirus 2000 that leads directly
1347 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001348
1349- xml: New version detection code allows PyXML to override standard
1350 XML package if PyXML version is greater than 0.6.1.
1351
Fred Drake64bb3802000-09-26 16:21:35 +00001352- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1353 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1354 tree only for nodes which are sufficiently interesting to a specific
1355 application. Does not provide the HTML-specific extensions. Still
1356 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001357
Fred Drake64bb3802000-09-26 16:21:35 +00001358- xml.sax: SAX 2 support for Python, including all the handler
1359 interfaces needed to process XML 1.0 compliant XML. Some
1360 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001361
Fred Drake64bb3802000-09-26 16:21:35 +00001362- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1363 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001364
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001365
Jeremy Hylton1b618592000-09-26 05:32:36 +00001366C API
1367
1368- Add three new convenience functions for module initialization --
1369 PyModule_AddObject(), PyModule_AddIntConstant(), and
1370 PyModule_AddStringConstant().
1371
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001372- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001373 removed and add #error to Python.h if NULL isn't defined after
1374 #include of stdio.h.
1375
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001376- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001377 backwards compatibility (at the source level) with old extensions.
1378
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001379- A wrapper API was added for signal() and sigaction(). Instead of
1380 either function, always use PyOS_getsig() to get a signal handler
1381 and PyOS_setsig() to set one. A new convenience typedef
1382 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001383
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001384- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001385 internal data buffer and size of a string object -- or the default
1386 encoded version of a Unicode object.
1387
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001388- PyString_Size() and PyString_AsString() accept Unicode objects.
1389
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001390- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001391 exists). INT_MAX and LONG_MAX will always be defined, even if
1392 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001393
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001394- PyFloat_FromString takes a second argument, pend, that was
1395 effectively useless. It is now officially useless but preserved for
1396 backwards compatibility. If the pend argument is not NULL, *pend is
1397 set to NULL.
1398
1399- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1400 for the attribute name. See note on getattr() above.
1401
1402- A few bug fixes to argument processing for Unicode.
1403 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1404 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1405 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001406 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001407
1408- Py_BuildValue accepts B format (for bgen-generated code).
1409
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001410
Jeremy Hylton1b618592000-09-26 05:32:36 +00001411Internals
1412
1413- On Unix, fix code for finding Python installation directory so that
1414 it works when argv[0] is a relative path.
1415
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001416- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001417 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001418 rather than by generating a copy of the object.
1419
Tim Peters482c0212000-09-26 06:33:09 +00001420- Several of the internal Unicode tables are much smaller now, and
1421 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001422
Jeremy Hylton97693b02000-09-26 17:42:51 +00001423- In the garbage collector: Fixed bug in collection of tuples. Fixed
1424 bug that caused some instances to be removed from the container set
1425 while they were still live. Fixed parsing in gc.set_debug() for
1426 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001427
1428- Fixed refcount problem in instance deallocation that only occurred
1429 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1430
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001431- On Windows, getpythonregpath is now protected against null data in
1432 registry key.
1433
1434- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001435 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001436
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001437
Jeremy Hylton1b618592000-09-26 05:32:36 +00001438Build and platform-specific issues
1439
1440- Better support of GNU Pth via --with-pth configure option.
1441
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001442- Python/C API now properly exposed to dynamically-loaded extension
1443 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001444
1445- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1446 Don't define MS_SYNC to be zero when it is undefined. Added missing
1447 prototypes in posixmodule.c.
1448
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001449- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001450 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001451
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001452- Fix largefile support on older NetBSD systems and OpenBSD by adding
1453 define for TELL64.
1454
1455
1456Tools and other miscellany
1457
1458- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1459
1460- freeze: The modulefinder now works with 2.0 opcodes.
1461
Tim Petersa3a3a032000-11-30 05:22:44 +00001462- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001463 Move hackery of sys.argv until after the Tk instance has been
1464 created, which allows the application-specific Tkinter
1465 initialization to be executed if present; also pass an explicit
1466 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001467
Jeremy Hylton1b618592000-09-26 05:32:36 +00001468
1469What's new in 2.0 beta 1?
1470=========================
1471
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001472Source Incompatibilities
1473------------------------
1474
1475None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1476such as single-argument append(), connect() and bind(), and changes to
1477str(long) and repr(float).
1478
1479
1480Binary Incompatibilities
1481------------------------
1482
1483- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1484with Python 2.0; these extensions will have to be rebuilt for Python
14852.0.
1486
1487- On Windows, attempting to import a third party extension built for
1488Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1489can do about this. Check your PYTHONPATH environment variable!
1490
1491- Python bytecode files (*.pyc and *.pyo) are not compatible between
1492releases.
1493
1494
1495Overview of Changes Since 1.6
1496-----------------------------
1497
1498There are many new modules (including brand new XML support through
1499the xml package, and i18n support through the gettext module); a list
1500of all new modules is included below. Lots of bugs have been fixed.
1501
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001502The process for making major new changes to the language has changed
1503since Python 1.6. Enhancements must now be documented by a Python
1504Enhancement Proposal (PEP) before they can be accepted.
1505
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001506There are several important syntax enhancements, described in more
1507detail below:
1508
1509 - Augmented assignment, e.g. x += 1
1510
1511 - List comprehensions, e.g. [x**2 for x in range(10)]
1512
1513 - Extended import statement, e.g. import Module as Name
1514
1515 - Extended print statement, e.g. print >> file, "Hello"
1516
1517Other important changes:
1518
1519 - Optional collection of cyclical garbage
1520
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001521Python Enhancement Proposal (PEP)
1522---------------------------------
1523
1524PEP stands for Python Enhancement Proposal. A PEP is a design
1525document providing information to the Python community, or describing
1526a new feature for Python. The PEP should provide a concise technical
1527specification of the feature and a rationale for the feature.
1528
1529We intend PEPs to be the primary mechanisms for proposing new
1530features, for collecting community input on an issue, and for
1531documenting the design decisions that have gone into Python. The PEP
1532author is responsible for building consensus within the community and
1533documenting dissenting opinions.
1534
1535The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001536
1537Augmented Assignment
1538--------------------
1539
1540This must have been the most-requested feature of the past years!
1541Eleven new assignment operators were added:
1542
Guido van Rossume905e952000-09-05 12:42:46 +00001543 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001544
1545For example,
1546
1547 A += B
1548
1549is similar to
1550
1551 A = A + B
1552
1553except that A is evaluated only once (relevant when A is something
1554like dict[index].attr).
1555
1556However, if A is a mutable object, A may be modified in place. Thus,
1557if A is a number or a string, A += B has the same effect as A = A+B
1558(except A is only evaluated once); but if a is a list, A += B has the
1559same effect as A.extend(B)!
1560
1561Classes and built-in object types can override the new operators in
1562order to implement the in-place behavior; the not-in-place behavior is
1563used automatically as a fallback when an object doesn't implement the
1564in-place behavior. For classes, the method name is derived from the
1565method name for the corresponding not-in-place operator by inserting
1566an 'i' in front of the name, e.g. __iadd__ implements in-place
1567__add__.
1568
1569Augmented assignment was implemented by Thomas Wouters.
1570
1571
1572List Comprehensions
1573-------------------
1574
1575This is a flexible new notation for lists whose elements are computed
1576from another list (or lists). The simplest form is:
1577
1578 [<expression> for <variable> in <sequence>]
1579
Guido van Rossum56db0952000-09-06 23:34:25 +00001580For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001581This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001582
1583You can also add a condition:
1584
1585 [<expression> for <variable> in <sequence> if <condition>]
1586
1587For example, [w for w in words if w == w.lower()] would yield the list
1588of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001589than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001590
1591You can also have nested for loops and more than one 'if' clause. For
1592example, here's a function that flattens a sequence of sequences::
1593
1594 def flatten(seq):
1595 return [x for subseq in seq for x in subseq]
1596
1597 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1598
1599This prints
1600
1601 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1602
1603List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001604Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001605
1606
1607Extended Import Statement
1608-------------------------
1609
1610Many people have asked for a way to import a module under a different
1611name. This can be accomplished like this:
1612
1613 import foo
1614 bar = foo
1615 del foo
1616
1617but this common idiom gets old quickly. A simple extension of the
1618import statement now allows this to be written as follows:
1619
1620 import foo as bar
1621
1622There's also a variant for 'from ... import':
1623
1624 from foo import bar as spam
1625
1626This also works with packages; e.g. you can write this:
1627
1628 import test.regrtest as regrtest
1629
1630Note that 'as' is not a new keyword -- it is recognized only in this
1631context (this is only possible because the syntax for the import
1632statement doesn't involve expressions).
1633
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001634Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001635
1636
1637Extended Print Statement
1638------------------------
1639
1640Easily the most controversial new feature, this extension to the print
1641statement adds an option to make the output go to a different file
1642than the default sys.stdout.
1643
1644For example, to write an error message to sys.stderr, you can now
1645write:
1646
1647 print >> sys.stderr, "Error: bad dog!"
1648
1649As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001650evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001651
1652 print >> None, "Hello world"
1653
1654is equivalent to
1655
1656 print "Hello world"
1657
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001658Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001659
1660
1661Optional Collection of Cyclical Garbage
1662---------------------------------------
1663
1664Python is now equipped with a garbage collector that can hunt down
1665cyclical references between Python objects. It's no replacement for
1666reference counting; in fact, it depends on the reference counts being
1667correct, and decides that a set of objects belong to a cycle if all
1668their reference counts can be accounted for from their references to
1669each other. This devious scheme was first proposed by Eric Tiedemann,
1670and brought to implementation by Neil Schemenauer.
1671
1672There's a module "gc" that lets you control some parameters of the
1673garbage collection. There's also an option to the configure script
1674that lets you enable or disable the garbage collection. In 2.0b1,
1675it's on by default, so that we (hopefully) can collect decent user
1676experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001677performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001678off by default in the final 2.0 release.
1679
1680
1681Smaller Changes
1682---------------
1683
1684A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1685map(None, seq1, seq2, ...) when the sequences have the same length;
1686i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1687the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001688zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001689
1690sys.version_info is a tuple (major, minor, micro, level, serial).
1691
1692Dictionaries have an odd new method, setdefault(key, default).
1693dict.setdefault(key, default) returns dict[key] if it exists; if not,
1694it sets dict[key] to default and returns that value. Thus:
1695
1696 dict.setdefault(key, []).append(item)
1697
1698does the same work as this common idiom:
1699
1700 if not dict.has_key(key):
1701 dict[key] = []
1702 dict[key].append(item)
1703
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001704There are two new variants of SyntaxError that are raised for
1705indentation-related errors: IndentationError and TabError.
1706
1707Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1708escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001709
1710The limits on the size of expressions and file in Python source code
1711have been raised from 2**16 to 2**32. Previous versions of Python
1712were limited because the maximum argument size the Python VM accepted
1713was 2**16. This limited the size of object constructor expressions,
1714e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1715limit was raised thanks to a patch by Charles Waldman that effectively
1716fixes the problem. It is now much more likely that you will be
1717limited by available memory than by an arbitrary limit in Python.
1718
1719The interpreter's maximum recursion depth can be modified by Python
1720programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1721limit is the maximum number of recursive calls that can be made by
1722Python code. The limit exists to prevent infinite recursion from
1723overflowing the C stack and causing a core dump. The default value is
17241000. The maximum safe value for a particular platform can be found
1725by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001726
1727New Modules and Packages
1728------------------------
1729
1730atexit - for registering functions to be called when Python exits.
1731
1732imputil - Greg Stein's alternative API for writing custom import
1733hooks.
1734
1735pyexpat - an interface to the Expat XML parser, contributed by Paul
1736Prescod.
1737
1738xml - a new package with XML support code organized (so far) in three
1739subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1740would fill a volume. There's a special feature whereby a
1741user-installed package named _xmlplus overrides the standard
1742xmlpackage; this is intended to give the XML SIG a hook to distribute
1743backwards-compatible updates to the standard xml package.
1744
1745webbrowser - a platform-independent API to launch a web browser.
1746
1747
Guido van Rossume905e952000-09-05 12:42:46 +00001748Changed Modules
1749---------------
1750
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001751array -- new methods for array objects: count, extend, index, pop, and
1752remove
1753
1754binascii -- new functions b2a_hex and a2b_hex that convert between
1755binary data and its hex representation
1756
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001757calendar -- Many new functions that support features including control
1758over which day of the week is the first day, returning strings instead
1759of printing them. Also new symbolic constants for days of week,
1760e.g. MONDAY, ..., SUNDAY.
1761
1762cgi -- FieldStorage objects have a getvalue method that works like a
1763dictionary's get method and returns the value attribute of the object.
1764
1765ConfigParser -- The parser object has new methods has_option,
1766remove_section, remove_option, set, and write. They allow the module
1767to be used for writing config files as well as reading them.
1768
1769ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001770optionally support the RFC 959 REST command.
1771
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001772gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001773
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001774httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1775the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001776
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001777locale -- implement getdefaultlocale for Win32 and Macintosh
1778
1779marshal -- no longer dumps core when marshaling deeply nested or
1780recursive data structures
1781
1782os -- new functions isatty, seteuid, setegid, setreuid, setregid
1783
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001784os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1785support under Unix.
1786
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001787os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001788
1789os.path -- fix semantics of os.path.commonprefix
1790
1791smtplib -- support for sending very long messages
1792
1793socket -- new function getfqdn()
1794
1795readline -- new functions to read, write and truncate history files.
1796The readline section of the library reference manual contains an
1797example.
1798
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001799select -- add interface to poll system call
1800
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001801shutil -- new copyfileobj function
1802
1803SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1804HTTP server.
1805
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001806Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001807
1808urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001809e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001810
1811whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001812
1813
1814Obsolete Modules
1815----------------
1816
1817None. However note that 1.6 made a whole slew of modules obsolete:
1818stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1819poly, zmod, strop, util, whatsound.
1820
1821
1822Changed, New, Obsolete Tools
1823----------------------------
1824
Tim Peters8b092332000-09-05 20:15:25 +00001825None.
Guido van Rossume905e952000-09-05 12:42:46 +00001826
1827
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001828C-level Changes
1829---------------
1830
1831Several cleanup jobs were carried out throughout the source code.
1832
1833All C code was converted to ANSI C; we got rid of all uses of the
1834Py_PROTO() macro, which makes the header files a lot more readable.
1835
1836Most of the portability hacks were moved to a new header file,
1837pyport.h; several other new header files were added and some old
1838header files were removed, in an attempt to create a more rational set
1839of header files. (Few of these ever need to be included explicitly;
1840they are all included by Python.h.)
1841
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001842Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001843and Win64, especially for the new Intel Itanium processor. Mick also
1844added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001845
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001846The C APIs to return an object's size have been update to consistently
1847use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1848previous versions, the abstract interfaces used PyXXX_Length and the
1849concrete interfaces used PyXXX_Size. The old names,
1850e.g. PyObject_Length, are still available for backwards compatibility
1851at the API level, but are deprecated.
1852
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001853The PyOS_CheckStack function has been implemented on Windows by
1854Fredrik Lundh. It prevents Python from failing with a stack overflow
1855on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001856
1857The GC changes resulted in creation of two new slots on object,
1858tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001859the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001860
1861The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001862C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001863
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001864PyErr_Format has been updated to automatically calculate the size of
1865the buffer needed to hold the formatted result string. This change
1866prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001867
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001868New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001869
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001870PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1871that are the same as their non-Ex counterparts except they take an
1872extra flag argument that tells them to close the file when done.
1873
1874XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001875
Tim Peters8b092332000-09-05 20:15:25 +00001876
1877Windows Changes
1878---------------
1879
1880New popen2/popen3/peopen4 in os module (see Changed Modules above).
1881
1882os.popen is much more usable on Windows 95 and 98. See Microsoft
1883Knowledge Base article Q150956. The Win9x workaround described there
1884is implemented by the new w9xpopen.exe helper in the root of your
1885Python installation. Note that Python uses this internally; it is not
1886a standalone program.
1887
1888Administrator privileges are no longer required to install Python
1889on Windows NT or Windows 2000. If you have administrator privileges,
1890Python's registry info will be written under HKEY_LOCAL_MACHINE.
1891Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001892under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001893uses of Python, but will prevent some advanced uses from working
1894(for example, running a Python script as an NT service, or possibly
1895from CGI).
1896
1897[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1898installer; instead, it installs the needed Tcl/Tk files directly in the
1899Python directory. If you already have a Tcl/Tk installation, this
1900wastes some disk space (about 4 Megs) but avoids problems with
1901conflicting Tcl/Tk installations, and makes it much easier for Python
1902to ensure that Tcl/Tk can find all its files.
1903
1904[This was new in 1.6] The Windows installer now installs by default in
1905\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1906
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001907
1908Updates to the changes between 1.5.2 and 1.6
1909--------------------------------------------
1910
1911The 1.6 NEWS file can't be changed after the release is done, so here
1912is some late-breaking news:
1913
1914New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1915and changes to getlocale() and setlocale().
1916
1917The new module is now enabled per default.
1918
1919It is not true that the encodings codecs cannot be used for normal
1920strings: the string.encode() (which is also present on 8-bit strings
1921!) allows using them for 8-bit strings too, e.g. to convert files from
1922cp1252 (Windows) to latin-1 or vice-versa.
1923
1924Japanese codecs are available from Tamito KAJIYAMA:
1925http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1926
1927
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001928======================================================================