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Guido van Rossum55a78992001-07-17 17:22:32 +00001What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +00002===========================
3
4Core
Tim Petersa814db52001-05-14 07:05:58 +00005
Guido van Rossum55a78992001-07-17 17:22:32 +00006- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00007 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00008 more 'yield' statements. See PEP 255. Since this adds a new
9 keyword to the language, this feature must be enabled by including a
10 future statement: "from __future__ import generators" (see PEP 236).
11 Generators will become a standard feature in a future release
12 (probably 2.3). Without this future statement, 'yield' remains an
13 ordinary identifier, but a warning is issued each time it is used.
14 (These warnings currently don't conform to the warnings framework of
15 PEP 230; we intend to fix this in 2.2a2.)
16
Marc-André Lemburg12e74b32001-05-22 08:58:23 +000017- The UTF-16 codec was modified to be more RFC compliant. It will now
18 only remove BOM characters at the start of the string and then
19 only if running in native mode (UTF-16-LE and -BE won't remove a
20 leading BMO character).
21
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000022- Strings now have a new method .decode() to complement the already
23 existing .encode() method. These two methods provide direct access
24 to the corresponding decoders and encoders of the registered codecs.
25
26 To enhance the usability of the .encode() method, the special
27 casing of Unicode object return values was dropped (Unicode objects
28 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +000029
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000030 Both methods will now return whatever the codec in charge of the
31 requested encoding returns as object, e.g. Unicode codecs will
32 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
33 will return u"äöü"). This enables codec writer to create codecs
34 for various simple to use conversions.
35
36 New codecs were added to demonstrate these new features (the .encode()
37 and .decode() columns indicate the type of the returned objects):
38
39 Name | .encode() | .decode() | Description
40 ----------------------------------------------------------------------
41 uu | string | string | UU codec (e.g. for email)
42 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +000043 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000044 zlib | string | string | zlib compression
45 hex | string | string | 2-byte hex codec
46 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
47
Mark Hammond2a0af792001-05-14 03:09:36 +000048- Some operating systems now support the concept of a default Unicode
49 encoding for file system operations. Notably, Windows supports 'mbcs'
50 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +000051 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000052 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000053
54 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000055 functions that return filenames (such as os.listdir()) to return Python
56 string objects pre-encoded using the default file system encoding for
57 the platform. As this encoding is likely to be different from Python's
58 default encoding, converting this name to a Unicode object before passing
59 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000060 would attempt to use its default encoding (generally ASCII) rather than
61 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000062
Tim Petersa814db52001-05-14 07:05:58 +000063 In general, this change simply removes surprises when working with
64 Unicode and the file system, making these operations work as you expect,
65 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +000066 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +000067
Tim Peters61dff2b2001-05-08 15:43:37 +000068- Float (and complex) literals in source code were evaluated to full
69 precision only when running from a .py file; the same code loaded from a
70 .pyc (or .pyo) file could suffer numeric differences starting at about the
71 12th significant decimal digit. For example, on a machine with IEEE-754
72 floating arithmetic,
73
74 x = 9007199254740992.0
75 print long(x)
76
77 printed 9007199254740992 if run directly from .py, but 9007199254740000
78 if from a compiled (.pyc or .pyo) file. This was due to marshal using
79 str(float) instead of repr(float) when building code objects. marshal
80 now uses repr(float) instead, which should reproduce floats to full
81 machine precision (assuming the platform C float<->string I/O conversion
82 functions are of good quality).
83
84 This may cause floating-point results to change in some cases, and
85 usually for the better, but may also cause numerically unstable
86 algorithms to break.
87
Tim Peters2f228e72001-05-13 00:19:31 +000088- The implementation of dicts suffers fewer collisions, which has speed
89 benefits. However, the order in which dict entries appear in dict.keys(),
90 dict.values() and dict.items() may differ from previous releases for a
91 given dict. Nothing is defined about this order, so no program should
92 rely on it. Nevertheless, it's easy to write test cases that rely on the
93 order by accident, typically because of printing the str() or repr() of a
94 dict to an "expected results" file. See Lib/test/test_support.py's new
95 sortdict(dict) function for a simple way to display a dict in sorted
96 order.
97
Tim Peters7a3bfc32001-06-12 01:22:22 +000098- Many other small changes to dicts were made, resulting in faster
99 operation along the most common code paths.
100
Guido van Rossum10315822001-05-01 20:54:30 +0000101- Dictionary objects now support the "in" operator: "x in dict" means
102 the same as dict.has_key(x).
103
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000104- The update() method of dictionaries now accepts generic mapping
105 objects. Specifically the argument object must support the .keys()
106 and __getitem__() methods. This allows you to say, for example,
107 {}.update(UserDict())
108
Guido van Rossum10315822001-05-01 20:54:30 +0000109- Iterators were added; this is a generalized way of providing values
110 to a for loop. See PEP 234. There's a new built-in function iter()
111 to return an iterator. There's a new protocol to get the next value
112 from an iterator using the next() method (in Python) or the
113 tp_iternext slot (in C). There's a new protocol to get iterators
114 using the __iter__() method (in Python) or the tp_iter slot (in C).
115 Iterating (i.e. a for loop) over a dictionary generates its keys.
116 Iterating over a file generates its lines.
117
Tim Petersf553f892001-05-01 20:45:31 +0000118- The following functions were generalized to work nicely with iterator
119 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000120 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000121 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
122 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000123 join() method of strings
124 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000125 'x in y' and 'x not in y' (PySequence_Contains() in C API)
126 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000127 right-hand side of assignment statements with multiple targets, such as
128 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000129
Tim Petersd85e1022001-05-11 21:51:48 +0000130- Accessing module attributes is significantly faster (for example,
131 random.random or os.path or yourPythonModule.yourAttribute).
132
Tim Peterse63415e2001-05-08 04:38:29 +0000133- Comparing dictionary objects via == and != is faster, and now works even
134 if the keys and values don't support comparisons other than ==.
135
Tim Peters95bf9392001-05-10 08:32:44 +0000136- Comparing dictionaries in ways other than == and != is slower: there were
137 insecurities in the dict comparison implementation that could cause Python
138 to crash if the element comparison routines for the dict keys and/or
139 values mutated the dicts. Making the code bulletproof slowed it down.
140
Tim Peterseb28ef22001-06-02 05:27:19 +0000141- Collisions in dicts are resolved via a new approach, which can help
142 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000143 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000144 faster now. Thanks to Christian Tismer for pointing out the cause and
145 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000146
Tim Peters52e155e2001-06-16 05:42:57 +0000147- repr() is much faster for large containers (dict, list, tuple).
148
149
Tim Petersa814db52001-05-14 07:05:58 +0000150Library
151
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000152- The flags used in dlopen calls can now be configured using
153 sys.setdlopenflags and queried using sys.getdlopenflags.
154
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000155- Fredrik Lundh's xmlrpclib is now a standard library module. This
156 provides full client-side XML-RPC support. In addition,
157 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
158 one asyncore-based). Thanks to Eric Raymond for the documentation.
159
Guido van Rossum643d3912001-07-05 14:46:25 +0000160- The xrange() object is simplified: it no longer supports slicing,
161 repetition, comparisons, efficient 'in' checking, the tolist()
162 method, or the start, stop and step attributes. See PEP 260.
163
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000164- A new function fnmatch.filter to filter lists of file names was added.
165
Barry Warsawffd674d2001-05-22 16:00:10 +0000166- calendar.py uses month and day names based on the current locale.
167
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000168- strop is now *really* obsolete (this was announced before with 1.6),
169 and issues DeprecationWarning when used (except for the four items
170 that are still imported into string.py).
171
Tim Petersa814db52001-05-14 07:05:58 +0000172- Cookie.py now sorts key+value pairs by key in output strings.
173
174- pprint.isrecursive(object) didn't correctly identify recursive objects.
175 Now it does.
176
Tim Peters95b3f782001-05-14 18:39:41 +0000177- pprint functions now much faster for large containers (tuple, list, dict).
178
Tim Peters7b9542a2001-06-10 23:40:19 +0000179- New 'q' and 'Q' format codes in the struct module, corresponding to C
180 types "long long" and "unsigned long long" (on Windows, __int64). In
181 native mode, these can be used only when the platform C compiler supports
182 these types (when HAVE_LONG_LONG is #define'd by the Python config
183 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000184 In standard mode, 'q' and 'Q' are supported on all platforms, and are
185 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000186
Guido van Rossum83213cc2001-06-12 16:48:52 +0000187- The site module installs a new built-in function 'help' that invokes
188 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
189 it displays a message reminding the user to use 'help()' or
190 'help(object)'.
191
Tim Petersa814db52001-05-14 07:05:58 +0000192Tests
193
194- New test_mutants.py runs dict comparisons where the key and value
195 comparison operators mutute the dicts randomly during comparison. This
196 rapidly causes Python to crash under earlier releases (not for the faint
197 of heart: it can also cause Win9x to freeze or reboot!).
198
199- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000200 pprint.isreadable() return sensible results. Also verifies that simple
201 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000202
Tim Peters58e0a8c2001-05-14 22:32:33 +0000203New platforms
204
205- Python should compile and run out of the box using the Borland C
206 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000207
Tim Peters4324aa32001-05-28 22:30:08 +0000208C API
209
210- Removed the unused last_is_sticky argument from the internal
211 _PyTuple_Resize(). If this affects you, you were cheating.
212
213
Guido van Rossum55a78992001-07-17 17:22:32 +0000214======================================================================
215
216
Guido van Rossumffe13be2001-04-16 18:46:45 +0000217What's New in Python 2.1 (final)?
218=================================
219
220We only changed a few things since the last release candidate, all in
221Python library code:
222
223- A bug in the locale module was fixed that affected locales which
224 define no grouping for numeric formatting.
225
226- A few bugs in the weakref module's implementations of weak
227 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
228 and the test suite was updated to check for these bugs.
229
230- An old bug in the os.path.walk() function (introduced in Python
231 2.0!) was fixed: a non-existent file would cause an exception
232 instead of being ignored.
233
234- Fixed a few bugs in the new symtable module found by Neil Norwitz's
235 PyChecker.
236
237
Guido van Rossum5b08f132001-04-16 02:05:23 +0000238What's New in Python 2.1c2?
239===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000240
Guido van Rossum5b08f132001-04-16 02:05:23 +0000241A flurry of small changes, and one showstopper fixed in the nick of
242time made it necessary to release another release candidate. The list
243here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000244
Guido van Rossum5b08f132001-04-16 02:05:23 +0000245Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000246
Guido van Rossum5b08f132001-04-16 02:05:23 +0000247- Tim discovered a nasty bug in the dictionary code, caused by
248 PyDict_Next() calling dict_resize(), and the GC code's use of
249 PyDict_Next() violating an assumption in dict_items(). This was
250 fixed with considerable amounts of band-aid, but the net effect is a
251 saner and more robust implementation.
252
253- Made a bunch of symbols static that were accidentally global.
254
255Build and Ports
256
257- The setup.py script didn't check for a new enough version of zlib
258 (1.1.3 is needed). Now it does.
259
260- Changed "make clean" target to also remove shared libraries.
261
262- Added a more general warning about the SGI Irix optimizer to README.
263
264Library
265
266- Fix a bug in urllib.basejoin("http://host", "../file.html") which
267 omitted the slash between host and file.html.
268
269- The mailbox module's _Mailbox class contained a completely broken
270 and undocumented seek() method. Ripped it out.
271
272- Fixed a bunch of typos in various library modules (urllib2, smtpd,
273 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
274
275- Fixed a few last-minute bugs in unittest.
276
277Extensions
278
279- Reverted the patch to the OpenSSL code in socketmodule.c to support
280 RAND_status() and the EGD, and the subsequent patch that tried to
281 fix it for pre-0.9.5 versions; the problem with the patch is that on
282 some systems it issues a warning whenever socket is imported, and
283 that's unacceptable.
284
285Tests
286
287- Fixed the pickle tests to work with "import test.test_pickle".
288
289- Tweaked test_locale.py to actually run the test Windows.
290
291- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
292 not "wb" (which is not a valid mode at all).
293
294- Fix pstats browser crashes. Import readline if it exists to make
295 the user interface nicer.
296
297- Add "import thread" to the top of test modules that import the
298 threading module (test_asynchat and test_threadedtempfile). This
299 prevents test failures caused by a broken threading module resulting
300 from a previously caught failed import.
301
302- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
303 needed on some platforms (e.g. Solaris 8) when the tests are run
304 twice in succession.
305
306- Skip rather than fail test_sunaudiodev if no audio device is found.
307
308
309What's New in Python 2.1c1?
310===========================
311
312This list was significantly updated when 2.1c2 was released; the 2.1c1
313release didn't mention most changes that were actually part of 2.1c1:
314
315Legal
316
317- Copyright was assigned to the Python Software Foundation (PSF) and a
318 PSF license (very similar to the CNRI license) was added.
319
320- The CNRI copyright notice was updated to include 2001.
321
322Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000323
Guido van Rossumc9932722001-04-12 02:31:27 +0000324- After a public outcry, assignment to __debug__ is no longer illegal;
325 instead, a warning is issued. It will become illegal in 2.2.
326
Guido van Rossum5b08f132001-04-16 02:05:23 +0000327- Fixed a core dump with "%#x" % 0, and changed the semantics so that
328 "%#x" now always prepends "0x", even if the value is zero.
329
330- Fixed some nits in the bytecode compiler.
331
332- Fixed core dumps when calling certain kinds of non-functions.
333
334- Fixed various core dumps caused by reference count bugs.
335
336Build and Ports
337
338- Use INSTALL_SCRIPT to install script files.
339
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000340- New port: SCO Unixware 7, by Billy G. Allie.
341
Guido van Rossum5b08f132001-04-16 02:05:23 +0000342- Updated RISCOS port.
343
344- Updated BeOS port and notes.
345
346- Various other porting problems resolved.
347
348Library
349
350- The TERMIOS and SOCKET modules are now truly obsolete and
351 unnecessary. Their symbols are incorporated in the termios and
352 socket modules.
353
354- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
355 better tests for pickling.
356
357- threading: make Condition.wait() robust against KeyboardInterrupt.
358
359- zipfile: add support to zipfile to support opening an archive
360 represented by an open file rather than a file name. Fix bug where
361 the archive was not properly closed. Fixed a bug in this bugfix
362 where flush() was called for a read-only file.
363
364- imputil: added an uninstall() method to the ImportManager.
365
366- Canvas: fixed bugs in lower() and tkraise() methods.
367
368- SocketServer: API change (added overridable close_request() method)
369 so that the TCP server can explicitly close the request.
370
371- pstats: Eric Raymond added a simple interactive statistics browser,
372 invoked when the module is run as a script.
373
374- locale: fixed a problem in format().
375
376- webbrowser: made it work when the BROWSER environment variable has a
377 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
378 KDE 2. Fixed some other nits.
379
380- unittest: changes to allow using a different exception than
381 AssertionError, and added a few more function aliases. Some other
382 small changes.
383
384- urllib, urllib2: fixed redirect problems and a coupleof other nits.
385
386- asynchat: fixed a critical bug in asynchat that slipped through the
387 2.1b2 release. Fixed another rare bug.
388
389- Fix some unqualified except: clauses (always a bad code example).
390
391XML
392
393- pyexpat: new API get_version_string().
394
395- Fixed some minidom bugs.
396
397Extensions
398
399- Fixed a core dump in _weakref. Removed the weakref.mapping()
400 function (it adds nothing to the API).
401
402- Rationalized the use of header files in the readline module, to make
403 it compile (albeit with some warnings) with the very recent readline
404 4.2, without breaking for earlier versions.
405
406- Hopefully fixed a buffering problem in linuxaudiodev.
407
408- Attempted a fix to make the OpenSSL support in the socket module
409 work again with pre-0.9.5 versions of OpenSSL.
410
411Tests
412
413- Added a test case for asynchat and asyncore.
414
415- Removed coupling between tests where one test failing could break
416 another.
417
418Tools
419
420- Ping added an interactive help browser to pydoc, fixed some nits
421 in the rest of the pydoc code, and added some features to his
422 inspect module.
423
424- An updated python-mode.el version 4.1 which integrates Ken
425 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
426 much nicer in XEmacs and Emacs. When stepping through your program
427 with pdb, in either the shell window or the *Python* window, the
428 source file and line will be tracked by an arrow. Very cool!
429
430- IDLE: syntax warnings in interactive mode are changed into errors.
431
432- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000433 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000434
435- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000436
Barry Warsaw11e89c72001-04-11 20:37:57 +0000437
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000438What's New in Python 2.1 beta 2?
439================================
440
Guido van Rossum053ae352001-03-22 14:17:21 +0000441(Unlisted are many fixed bugs, more documentation, etc.)
442
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000443Core language, builtins, and interpreter
444
Guido van Rossum053ae352001-03-22 14:17:21 +0000445- The nested scopes work (enabled by "from __future__ import
446 nested_scopes") is completed; in particular, the future now extends
447 into code executed through exec, eval() and execfile(), and into the
448 interactive interpreter.
449
450- When calling a base class method (e.g. BaseClass.__init__(self)),
451 this is now allowed even if self is not strictly spoken a class
452 instance (e.g. when using metaclasses or the Don Beaudry hook).
453
454- Slice objects are now comparable but not hashable; this prevents
455 dict[:] from being accepted but meaningless.
456
457- Complex division is now calculated using less braindead algorithms.
458 This doesn't change semantics except it's more likely to give useful
459 results in extreme cases. Complex repr() now uses full precision
460 like float repr().
461
462- sgmllib.py now calls handle_decl() for simple <!...> declarations.
463
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000464- It is illegal to assign to the name __debug__, which is set when the
465 interpreter starts. It is effectively a compile-time constant.
466
467- A warning will be issued if a global statement for a variable
468 follows a use or assignment of that variable.
469
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000470Standard library
471
Guido van Rossum053ae352001-03-22 14:17:21 +0000472- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
473 inspired by JUnit), is now part of the standard library. You now
474 have a choice of two testing frameworks: unittest requires you to
475 write testcases as separate code, doctest gathers them from
476 docstrings. Both approaches have their advantages and
477 disadvantages.
478
479- A new module Tix was added, which wraps the Tix extension library
480 for Tk. With that module, it is not necessary to statically link
481 Tix with _tkinter, since Tix will be loaded with Tcl's "package
482 require" command. See Demo/tix/.
483
484- tzparse.py is now obsolete.
485
486- In gzip.py, the seek() and tell() methods are removed -- they were
487 non-functional anyway, and it's better if callers can test for their
488 existence with hasattr().
489
490Python/C API
491
492- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
493 that's already in the dictionary during a PyDict_Next() iteration.
494 This used to fail occasionally when a dictionary resize operation
495 could be triggered that would rehash all the keys. All other
496 modifications to the dictionary are still off-limits during a
497 PyDict_Next() iteration!
498
499- New extended APIs related to passing compiler variables around.
500
501- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
502 implement isinstance() and issubclass().
503
504- Py_BuildValue() now has a "D" conversion to create a Python complex
505 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000506
Fred Drake4e262a92001-03-22 18:26:47 +0000507- Extensions types which support weak references must now set the
508 field allocated for the weak reference machinery to NULL themselves;
509 this is done to avoid the cost of checking each object for having a
510 weakly referencable type in PyObject_INIT(), since most types are
511 not weakly referencable.
512
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000513- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
514 free variables and cell variables to and from the frame's f_locals.
515
516- Variants of several functions defined in pythonrun.h have been added
517 to support the nested_scopes future statement. The variants all end
518 in Flags and take an extra argument, a PyCompilerFlags *; examples:
519 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
520 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000521 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000522
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000523Distutils
524
525- the sdist command now writes a PKG-INFO file, as described in PEP 241,
526 into the release tree.
527
Tim Peters0e57abf2001-05-02 07:39:38 +0000528- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000529 (an uninstaller, more customization of the installer's display)
530
531- from Jack Jansen: added Mac-specific code to generate a dialog for
532 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000533 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000534 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000535
536- added 'platforms' and 'keywords' to the set of metadata that can be
537 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000538
539- applied patches from Jason Tishler to make the compiler class work with
540 Cygwin.
541
542
Tim Peters2fe289a2001-03-01 22:19:38 +0000543What's New in Python 2.1 beta 1?
544================================
Tim Petersd66595f2001-02-04 03:09:53 +0000545
546Core language, builtins, and interpreter
547
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000548- Following an outcry from the community about the amount of code
549 broken by the nested scopes feature introduced in 2.1a2, we decided
550 to make this feature optional, and to wait until Python 2.2 (or at
551 least 6 months) to make it standard. The option can be enabled on a
552 per-module basis by adding "from __future__ import nested_scopes" at
553 the beginning of a module (before any other statements, but after
554 comments and an optional docstring). See PEP 236 (Back to the
555 __future__) for a description of the __future__ statement. PEP 227
556 (Statically Nested Scopes) has been updated to reflect this change,
557 and to clarify the semantics in a number of endcases.
558
559- The nested scopes code, when enabled, has been hardened, and most
560 bugs and memory leaks in it have been fixed.
561
562- Compile-time warnings are now generated for a number of conditions
563 that will break or change in meaning when nested scopes are enabled:
564
565 - Using "from...import *" or "exec" without in-clause in a function
566 scope that also defines a lambda or nested function with one or
567 more free (non-local) variables. The presence of the import* or
568 bare exec makes it impossible for the compiler to determine the
569 exact set of local variables in the outer scope, which makes it
570 impossible to determine the bindings for free variables in the
571 inner scope. To avoid the warning about import *, change it into
572 an import of explicitly name object, or move the import* statement
573 to the global scope; to avoid the warning about bare exec, use
574 exec...in... (a good idea anyway -- there's a possibility that
575 bare exec will be deprecated in the future).
576
577 - Use of a global variable in a nested scope with the same name as a
578 local variable in a surrounding scope. This will change in
579 meaning with nested scopes: the name in the inner scope will
580 reference the variable in the outer scope rather than the global
581 of the same name. To avoid the warning, either rename the outer
582 variable, or use a global statement in the inner function.
583
Neil Schemenauera35c6882001-02-27 04:45:05 +0000584- An optional object allocator has been included. This allocator is
585 optimized for Python objects and should be faster and use less memory
586 than the standard system allocator. It is not enabled by default
587 because of possible thread safety problems. The allocator is only
588 protected by the Python interpreter lock and it is possible that some
589 extension modules require a thread safe allocator. The object
590 allocator can be enabled by providing the "--with-pymalloc" option to
591 configure.
592
Tim Petersd66595f2001-02-04 03:09:53 +0000593Standard library
594
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000595- pyexpat now detects the expat version if expat.h defines it. A
596 number of additional handlers are provided, which are only available
597 since expat 1.95. In addition, the methods SetParamEntityParsing and
598 GetInputContext of Parser objects are available with 1.95.x
599 only. Parser objects now provide the ordered_attributes and
600 specified_attributes attributes. A new module expat.model was added,
601 which offers a number of additional constants if 1.95.x is used.
602
603- xml.dom offers the new functions registerDOMImplementation and
604 getDOMImplementation.
605
606- xml.dom.minidom offers a toprettyxml method. A number of DOM
607 conformance issues have been resolved. In particular, Element now
608 has an hasAttributes method, and the handling of namespaces was
609 improved.
610
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000611- Ka-Ping Yee contributed two new modules: inspect.py, a module for
612 getting information about live Python code, and pydoc.py, a module
613 for interactively converting docstrings to HTML or text.
614 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000615 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000616 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
617 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000618
Tim Peters1eff7962001-03-01 02:31:33 +0000619- New library module difflib.py, primarily packaging the SequenceMatcher
620 class at the heart of the popular ndiff.py file-comparison tool.
621
622- doctest.py (a framework for verifying Python code examples in docstrings)
623 is now part of the std library.
624
Tim Petersd66595f2001-02-04 03:09:53 +0000625Windows changes
626
Guido van Rossume3955a82001-03-02 14:05:59 +0000627- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
628 small GUI that lets you browse the module docstrings using your
629 default web browser.
630
Tim Peters1eff7962001-03-01 02:31:33 +0000631- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
632 Platforms) is implemented. See
633
634 http://python.sourceforge.net/peps/pep-0235.html
635
636 for full details, especially the "Current Lower-Left Semantics" section.
637 The new Windows import rules are simpler than before:
638
639 A. If the PYTHONCASEOK environment variable exists, same as
640 before: silently accept the first case-insensitive match of any
641 kind; raise ImportError if none found.
642
643 B. Else search sys.path for the first case-sensitive match; raise
644 ImportError if none found.
645
646 The same rules have been implented on other platforms with case-
647 insensitive but case-preserving filesystems too (including Cygwin, and
648 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000649
Tim Peters25a9ce32001-02-19 07:06:36 +0000650- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
651 what it's supposed to do (and does do under NT and 2000) via direct
652 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000653 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000654 all Win9x systems before.
655
Tim Peters1eff7962001-03-01 02:31:33 +0000656- Build: Subproject _test (effectively) renamed to _testcapi.
657
Tim Peters2fe289a2001-03-01 22:19:38 +0000658New platforms
659
660- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
661 Thanks to Steven Majewski!
662
663- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
664 Tishler!
665
Guido van Rossum9089b272001-03-02 06:49:50 +0000666- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
667 Schwertberger! See RISCOS/README for more information -- it seems
668 that because of the bizarre filename conventions on RISCOS, no port
669 to that platform is easy. Note that the new variable os.endsep is
670 silently supported in order to make life easier on this platform,
671 but we don't advertise it because it's not worth for most folks to
672 care about RISCOS portability.
673
Tim Peters25a9ce32001-02-19 07:06:36 +0000674
Tim Petersd7b5e882001-01-25 03:36:26 +0000675What's New in Python 2.1 alpha 2?
676=================================
Tim Peters40ead762001-01-27 05:35:26 +0000677
Tim Petersd7b5e882001-01-25 03:36:26 +0000678Core language, builtins, and interpreter
679
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000680- Scopes nest. If a name is used in a function or class, but is not
681 local, the definition in the nearest enclosing function scope will
682 be used. One consequence of this change is that lambda statements
683 could reference variables in the namespaces where the lambda is
684 defined. In some unusual cases, this change will break code.
685
686 In all previous version of Python, names were resolved in exactly
687 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000688 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000689 function A is defined within a function B, the names bound in B are
690 not visible in A. The new rules make names bound in B visible in A,
691 unless A contains a name binding that hides the binding in B.
692
693 Section 4.1 of the reference manual describes the new scoping rules
694 in detail. The test script in Lib/test/test_scope.py demonstrates
695 some of the effects of the change.
696
697 The new rules will cause existing code to break if it defines nested
698 functions where an outer function has local variables with the same
699 name as globals or builtins used by the inner function. Example:
700
701 def munge(str):
702 def helper(x):
703 return str(x)
704 if type(str) != type(''):
705 str = helper(str)
706 return str.strip()
707
708 Under the old rules, the name str in helper() is bound to the
709 builtin function str(). Under the new rules, it will be bound to
710 the argument named str and an error will occur when helper() is
711 called.
712
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000713- The compiler will report a SyntaxError if "from ... import *" occurs
714 in a function or class scope. The language reference has documented
715 that this case is illegal, but the compiler never checked for it.
716 The recent introduction of nested scope makes the meaning of this
717 form of name binding ambiguous. In a future release, the compiler
718 may allow this form when there is no possibility of ambiguity.
719
Tim Peters40ead762001-01-27 05:35:26 +0000720- repr(string) is easier to read, now using hex escapes instead of octal,
721 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
722
723 >>> "\texample \r\n" + chr(0) + chr(255)
724 '\texample \r\n\x00\xff' # in 2.1
725 '\011example \015\012\000\377' # in 2.0
726
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000727- Functions are now compared and hashed by identity, not by value, since
728 the func_code attribute is writable.
729
Fred Drakefb9d7122001-02-01 20:00:40 +0000730- Weak references (PEP 205) have been added. This involves a few
731 changes in the core, an extension module (_weakref), and a Python
732 module (weakref). The weakref module is the public interface. It
733 includes support for "explicit" weak references, proxy objects, and
734 mappings with weakly held values.
735
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000736- A 'continue' statement can now appear in a try block within the body
737 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000738 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000739
Tim Petersd7b5e882001-01-25 03:36:26 +0000740Standard library
741
Barry Warsaw30dbd142001-01-31 22:14:01 +0000742- mailbox.py now has a new class, PortableUnixMailbox which is
743 identical to UnixMailbox but uses a more portable scheme for
744 determining From_ separators. Also, the constructors for all the
745 classes in this module have a new optional `factory' argument, which
746 is a callable used when new message classes must be instantiated by
747 the next() method.
748
Tim Petersd7b5e882001-01-25 03:36:26 +0000749- random.py is now self-contained, and offers all the functionality of
750 the now-deprecated whrandom.py. See the docs for details. random.py
751 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000752 and restoring the internal state of the generator; and jumpahead(n),
753 for quickly forcing the internal state to be the same as if n calls to
754 random() had been made. The latter is particularly useful for multi-
755 threaded programs, creating one instance of the random.Random() class for
756 each thread, then using .jumpahead() to force each instance to use a
757 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000758
Tim Peters0de88fc2001-02-01 04:59:18 +0000759- random.py's seed() function is new. For bit-for-bit compatibility with
760 prior releases, use the whseed function instead. The new seed function
761 addresses two problems: (1) The old function couldn't produce more than
762 about 2**24 distinct internal states; the new one about 2**45 (the best
763 that can be done in the Wichmann-Hill generator). (2) The old function
764 sometimes produced identical internal states when passed distinct
765 integers, and there was no simple way to predict when that would happen;
766 the new one guarantees to produce distinct internal states for all
767 arguments in [0, 27814431486576L).
768
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000769- The socket module now supports raw packets on Linux. The socket
770 family is AF_PACKET.
771
Tim Peters9ea17ac2001-02-02 05:57:15 +0000772- test_capi.py is a start at running tests of the Python C API. The tests
773 are implemented by the new Modules/_testmodule.c.
774
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000775- A new extension module, _symtable, provides provisional access to the
776 internal symbol table used by the Python compiler. A higher-level
777 interface will be added on top of _symtable in a future release.
778
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000779- Removed the obsolete soundex module.
780
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000781- xml.dom.minidom now uses the standard DOM exceptions. Node supports
782 the isSameNode method; NamedNodeMap the get method.
783
784- xml.sax.expatreader supports the lexical handler property; it
785 generates comment, startCDATA, and endCDATA events.
786
Tim Petersee826f82001-01-31 19:39:44 +0000787Windows changes
788
789- Build procedure: the zlib project is built in a different way that
790 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000791 the zlib binary used. See PCbuild\readme.txt for details. Your old
792 zlib-related directories can be deleted; you'll need to download fresh
793 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000794
Tim Peters9ea17ac2001-02-02 05:57:15 +0000795- Build: New subproject _test for the benefit of test_capi.py (see above).
796
Tim Petersb16c56f2001-02-02 21:24:51 +0000797- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
798 interface to some Python compiler internals).
799
800- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000801 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000802
Tim Petersa3a3a032000-11-30 05:22:44 +0000803What's New in Python 2.1 alpha 1?
804=================================
805
806Core language, builtins, and interpreter
807
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000808- There is a new Unicode companion to the PyObject_Str() API
809 called PyObject_Unicode(). It behaves in the same way as the
810 former, but assures that the returned value is an Unicode object
811 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000812
Guido van Rossumf98eda02001-01-17 15:54:45 +0000813- The comparison operators support "rich comparison overloading" (PEP
814 207). C extension types can provide a rich comparison function in
815 the new tp_richcompare slot in the type object. The cmp() function
816 and the C function PyObject_Compare() first try the new rich
817 comparison operators before trying the old 3-way comparison. There
818 is also a new C API PyObject_RichCompare() (which also falls back on
819 the old 3-way comparison, but does not constrain the outcome of the
820 rich comparison to a Boolean result).
821
822 The rich comparison function takes two objects (at least one of
823 which is guaranteed to have the type that provided the function) and
824 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
825 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
826 object, which may be NotImplemented (in which case the tp_compare
827 slot function is used as a fallback, if defined).
828
829 Classes can overload individual comparison operators by defining one
830 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000831 __ge__. There are no explicit "reflected argument" versions of
832 these; instead, __lt__ and __gt__ are each other's reflection,
833 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
834 reflection (similar at the C level). No other implications are
835 made; in particular, Python does not assume that == is the Boolean
836 inverse of !=, or that < is the Boolean inverse of >=. This makes
837 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000838
839 Classes or types that want to implement (in)equality tests but not
840 the ordering operators (i.e. unordered types) should implement ==
841 and !=, and raise an error for the ordering operators.
842
Guido van Rossuma88479f2001-01-18 14:28:08 +0000843 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000844 Boolean; e.g. a matrix type might want to return a matrix of bits
845 for A < B, giving elementwise comparisons. Such types should ensure
846 that any interpretation of their value in a Boolean context raises
847 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
848 at the C level) to always raise an exception.
849
Guido van Rossuma88479f2001-01-18 14:28:08 +0000850- Complex numbers use rich comparisons to define == and != but raise
851 an exception for <, <=, > and >=. Unfortunately, this also means
852 that cmp() of two complex numbers raises an exception when the two
853 numbers differ. Since it is not mathematically meaningful to compare
854 complex numbers except for equality, I hope that this doesn't break
855 too much code.
856
Tim Peters3389f192001-02-18 08:48:49 +0000857- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000858 not defined by the language, other than that it's arbitrary but
859 consistent (see the Reference Manual). An implementation detail changed
860 in 2.1a1 such that None now compares less than any other object. Code
861 relying on this new behavior (like code that relied on the previous
862 behavior) does so at its own risk.
863
Barry Warsaw573b5412001-01-15 20:43:18 +0000864- Functions and methods now support getting and setting arbitrarily
865 named attributes (PEP 232). Functions have a new __dict__
866 (a.k.a. func_dict) which hold the function attributes. Methods get
867 and set attributes on their underlying im_func. It is a TypeError
868 to set an attribute on a bound method.
869
Guido van Rossum051e3352001-01-15 19:11:10 +0000870- The xrange() object implementation has been improved so that
871 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
872 limitation that in this case len(xrange(sys.maxint)) can't be
873 calculated, but the common idiom "for i in xrange(sys.maxint)" will
874 work fine as long as the index i doesn't actually reach 2**31.
875 (Python uses regular ints for sequence and string indices; fixing
876 that is much more work.)
877
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000878- Two changes to from...import:
879
Guido van Rossumba381232001-02-03 15:06:40 +0000880 1) "from M import X" now works even if (after loading module M)
881 sys.modules['M'] is not a real module; it's basically a getattr()
882 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000883
884 2) "from M import *" now looks for M.__all__ to decide which names to
885 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
886 filters out names starting with '_' as before. Whether or not
887 __all__ exists, there's no restriction on the type of M.
888
Guido van Rossumf61f1662001-01-10 20:13:55 +0000889- File objects have a new method, xreadlines(). This is the fastest
890 way to iterate over all lines in a file:
891
892 for line in file.xreadlines():
893 ...do something to line...
894
895 See the xreadlines module (mentioned below) for how to do this for
896 other file-like objects.
897
898- Even if you don't use file.xreadlines(), you may expect a speedup on
899 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000900 quite a bit in platform-specific ways: on systems (like Linux) that
901 support flockfile(), getc_unlocked(), and funlockfile(), those are
902 used by default. On systems (like Windows) without getc_unlocked(),
903 a complicated (but still thread-safe) method using fgets() is used by
904 default.
905
Tim Petersd52269b2001-01-25 06:23:18 +0000906 You can force use of the fgets() method by #define'ing
907 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000908 getc_unlocked()).
909
Tim Petersd52269b2001-01-25 06:23:18 +0000910 You can force fgets() not to be used by #define'ing
911 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000912 test_bufio.py fails -- and let us know if it does!).
913
914- In addition, the fileinput module, while still slower than the other
915 methods on most platforms, has been sped up too, by using
916 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000917
918- Support for run-time warnings has been added, including a new
919 command line option (-W) to specify the disposition of warnings.
920 See the description of the warnings module below.
921
922- Extensive changes have been made to the coercion code. This mostly
923 affects extension modules (which can now implement mixed-type
924 numerical operators without having to use coercion), but
925 occasionally, in boundary cases the coercion semantics have changed
926 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000927 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000928 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000929 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000930
Guido van Rossumf98eda02001-01-17 15:54:45 +0000931- In connection with the coercion changes, a new built-in singleton
932 object, NotImplemented is defined. This can be returned for
933 operations that wish to indicate they are not implemented for a
934 particular combination of arguments. From C, this is
935 Py_NotImplemented.
936
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000937- The interpreter accepts now bytecode files on the command line even
938 if they do not have a .pyc or .pyo extension. On Linux, after executing
939
Martin v. Löwise214baa2001-02-04 22:37:56 +0000940import imp,sys,string
941magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
942reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
943open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000944
945 any byte code file can be used as an executable (i.e. as an argument
946 to execve(2)).
947
Tim Peters9940b802000-12-01 07:59:35 +0000948- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000949 character. In 1.6 and earlier, they never produced a sign,
950 and raised an error if the value of the long was too large
951 to fit in a Python int. In 2.0, they produced a sign if and
952 only if too large to fit in an int. This was inconsistent
953 across platforms (because the size of an int varies across
954 platforms), and inconsistent with hex() and oct(). Example:
955
956 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000957 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000958 'ffffffbe' # in 2.0 and before, on 32-bit machines
959 >>> hex(-0x42L)
960 '-0x42L' # in all versions of Python
961
Tim Peters9940b802000-12-01 07:59:35 +0000962 The behavior of %d formats for negative Python longs remains
963 the same as in 2.0 (although in 1.6 and before, they raised
964 an error if the long didn't fit in a Python int).
965
966 %u formats don't make sense for Python longs, but are allowed
967 and treated the same as %d in 2.1. In 2.0, a negative long
968 formatted via %u produced a sign if and only if too large to
969 fit in an int. In 1.6 and earlier, a negative long formatted
970 via %u raised an error if it was too big to fit in an int.
971
Guido van Rossum3661d392000-12-12 22:10:31 +0000972- Dictionary objects have an odd new method, popitem(). This removes
973 an arbitrary item from the dictionary and returns it (in the form of
974 a (key, value) pair). This can be useful for algorithms that use a
975 dictionary as a bag of "to do" items and repeatedly need to pick one
976 item. Such algorithms normally end up running in quadratic time;
977 using popitem() they can usually be made to run in linear time.
978
Tim Peters36cdad12000-12-29 02:06:45 +0000979Standard library
980
Thomas Woutersfe385252001-01-19 23:16:56 +0000981- In the time module, the time argument to the functions strftime,
982 localtime, gmtime, asctime and ctime is now optional, defaulting to
983 the current time (in the local timezone).
984
Guido van Rossumda91f222001-01-15 16:36:08 +0000985- The ftplib module now defaults to passive mode, which is deemed a
986 more useful default given that clients are often inside firewalls
987 these days. Note that this could break if ftplib is used to connect
988 to a *server* that is inside a firewall, from outside; this is
989 expected to be a very rare situation. To fix that, you can call
990 ftp.set_pasv(0).
991
Martin v. Löwis10a27872001-01-13 09:54:41 +0000992- The module site now treats .pth files not only for path configuration,
993 but also supports extensions to the initialization code: Lines starting
994 with import are executed.
995
Guido van Rossumf61f1662001-01-10 20:13:55 +0000996- There's a new module, warnings, which implements a mechanism for
997 issuing and filtering warnings. There are some new built-in
998 exceptions that serve as warning categories, and a new command line
999 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1000 turns warnings into errors). warnings.warn(message[, category])
1001 issues a warning message; this can also be called from C as
1002 PyErr_Warn(category, message).
1003
1004- A new module xreadlines was added. This exports a single factory
1005 function, xreadlines(). The intention is that this code is the
1006 absolutely fastest way to iterate over all lines in an open
1007 file(-like) object:
1008
1009 import xreadlines
1010 for line in xreadlines.xreadlines(file):
1011 ...do something to line...
1012
1013 This is equivalent to the previous the speed record holder using
1014 file.readlines(sizehint). Note that if file is a real file object
1015 (as opposed to a file-like object), this is equivalent:
1016
1017 for line in file.xreadlines():
1018 ...do something to line...
1019
Tim Peters36cdad12000-12-29 02:06:45 +00001020- The bisect module has new functions bisect_left, insort_left,
1021 bisect_right and insort_right. The old names bisect and insort
1022 are now aliases for bisect_right and insort_right. XXX_right
1023 and XXX_left methods differ in what happens when the new element
1024 compares equal to one or more elements already in the list: the
1025 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001026 right. Code that doesn't care where equal elements end up should
1027 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001028
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001029- The new curses.panel module wraps the panel library that forms part
1030 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1031
Guido van Rossumf61f1662001-01-10 20:13:55 +00001032- The SocketServer module now sets the allow_reuse_address flag by
1033 default in the TCPServer class.
1034
1035- A new function, sys._getframe(), returns the stack frame pointer of
1036 the caller. This is intended only as a building block for
1037 higher-level mechanisms such as string interpolation.
1038
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001039- The pyexpat module supports a number of new handlers, which are
1040 available only in expat 1.2. If invocation of a callback fails, it
1041 will report an additional frame in the traceback. Parser objects
1042 participate now in garbage collection. If expat reports an unknown
1043 encoding, pyexpat will try to use a Python codec; that works only
1044 for single-byte charsets. The parser type objects is exposed as
1045 XMLParserObject.
1046
1047- xml.dom now offers standard definitions for symbolic node type and
1048 exception code constants, and a hierarchy of DOM exceptions. minidom
1049 was adjusted to use them.
1050
1051- The conformance of xml.dom.minidom to the DOM specification was
1052 improved. It detects a number of additional error cases; the
1053 previous/next relationship works even when the tree is modified;
1054 Node supports the normalize() method; NamedNodeMap, DocumentType and
1055 DOMImplementation classes were added; Element supports the
1056 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1057 method.
1058
Guido van Rossumf61f1662001-01-10 20:13:55 +00001059Build issues
1060
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001061- For Unix (and Unix-compatible) builds, configuration and building of
1062 extension modules is now greatly automated. Rather than having to
1063 edit the Modules/Setup file to indicate which modules should be
1064 built and where their include files and libraries are, a
1065 distutils-based setup.py script now takes care of building most
1066 extension modules. All extension modules built this way are built
1067 as shared libraries. Only a few modules that must be linked
1068 statically are still listed in the Setup file; you won't need to
1069 edit their configuration.
1070
1071- Python should now build out of the box on Cygwin. If it doesn't,
1072 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001073
1074- Python now always uses its own (renamed) implementation of getopt()
1075 -- there's too much variation among C library getopt()
1076 implementations.
1077
1078- C++ compilers are better supported; the CXX macro is always set to a
1079 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001080
Tim Petersd92dfe02000-12-12 01:18:41 +00001081Windows changes
1082
1083- select module: By default under Windows, a select() call
1084 can specify no more than 64 sockets. Python now boosts
1085 this Microsoft default to 512. If you need even more than
1086 that, see the MS docs (you'll need to #define FD_SETSIZE
1087 and recompile Python from source).
1088
Guido van Rossumf61f1662001-01-10 20:13:55 +00001089- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1090 subdirectory is no more!
1091
Tim Petersa3a3a032000-11-30 05:22:44 +00001092
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001093What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001094=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001095
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001096Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001097changes are in the file HISTORY. If you are making the jump directly
1098from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1099HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001100
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001101Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1102the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1103http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001104
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001105--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001106
1107======================================================================
1108
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001109What's new in 2.0 (since release candidate 1)?
1110==============================================
1111
1112Standard library
1113
1114- The copy_reg module was modified to clarify its intended use: to
1115 register pickle support for extension types, not for classes.
1116 pickle() will raise a TypeError if it is passed a class.
1117
1118- Fixed a bug in gettext's "normalize and expand" code that prevented
1119 it from finding an existing .mo file.
1120
1121- Restored support for HTTP/0.9 servers in httplib.
1122
Tim Peters989b7b92000-10-16 20:24:53 +00001123- The math module was changed to stop raising OverflowError in case of
1124 underflow, and return 0 instead in underflow cases. Whether Python
1125 used to raise OverflowError in case of underflow was platform-
1126 dependent (it did when the platform math library set errno to ERANGE
1127 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001128
1129- Fixed a bug in StringIO that occurred when the file position was not
1130 at the end of the file and write() was called with enough data to
1131 extend past the end of the file.
1132
1133- Fixed a bug that caused Tkinter error messages to get lost on
1134 Windows. The bug was fixed by replacing direct use of
1135 interp->result with Tcl_GetStringResult(interp).
1136
1137- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1138 redirect response.
1139
1140- Several changes were made to distutils: Some debugging code was
1141 removed from util. Fixed the installer used when an external zip
1142 program (like WinZip) is not found; the source code for this
1143 installer is in Misc/distutils. check_lib() was modified to behave
1144 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1145 test for whether installed modules are on sys.path was changed to
1146 use both normcase() and normpath().
1147
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001148- Several minor bugs were fixed in the xml package (the minidom,
1149 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001150
1151- The regression test driver (regrtest.py) behavior when invoked with
1152 -l changed: It now reports a count of objects that are recognized as
1153 garbage but not freed by the garbage collector.
1154
Tim Peters989b7b92000-10-16 20:24:53 +00001155- The regression test for the math module was changed to test
1156 exceptional behavior when the test is run in verbose mode. Python
1157 cannot yet guarantee consistent exception behavior across platforms,
1158 so the exception part of test_math is run only in verbose mode, and
1159 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001160
1161Internals
1162
1163- PyOS_CheckStack() has been disabled on Win64, where it caused
1164 test_sre to fail.
1165
1166Build issues
1167
1168- Changed compiler flags, so that gcc is always invoked with -Wall and
1169 -Wstrict-prototypes. Users compiling Python with GCC should see
1170 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001171 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001172 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001173
Tim Petersa3a3a032000-11-30 05:22:44 +00001174- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001175
1176Tools and other miscellany
1177
1178- The compiler in Tools/compiler was updated to support the new
1179 language features introduced in 2.0: extended print statement, list
1180 comprehensions, and augmented assignments. The new compiler should
1181 also be backwards compatible with Python 1.5.2; the compiler will
1182 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001183 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001184
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001185What's new in 2.0 release candidate 1 (since beta 2)?
1186=====================================================
1187
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001188What is release candidate 1?
1189
1190We believe that release candidate 1 will fix all known bugs that we
1191intend to fix for the 2.0 final release. This release should be a bit
1192more stable than the previous betas. We would like to see even more
1193widespread testing before the final release, so we are producing this
1194release candidate. The final release will be exactly the same unless
1195any show-stopping (or brown bag) bugs are found by testers of the
1196release candidate.
1197
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001198All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001199to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001200
1201Core language, builtins, and interpreter
1202
1203- A bug that caused crashes when __coerce__ was used with augmented
1204 assignment, e.g. +=, was fixed.
1205
1206- Raise ZeroDivisionError when raising zero to a negative number,
1207 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1208 power operator and the result of math.pow(0.0, -2.0) will vary by
1209 platform. On Linux, it raises a ValueError.
1210
1211- A bug in Unicode string interpolation was fixed that occasionally
1212 caused errors with formats including "%%". For example, the
1213 following expression "%% %s" % u"abc" no longer raises a TypeError.
1214
1215- Compilation of deeply nested expressions raises MemoryError instead
1216 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1217
1218- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1219 rendering them useless. They are now written in binary mode again.
1220
1221Standard library
1222
1223- Keyword arguments are now accepted for most pattern and match object
1224 methods in SRE, the standard regular expression engine.
1225
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001226- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001227 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001228
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001229- Several bugs in the Unicode handling and error handling in _tkinter
1230 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001231
1232- Fix memory management errors in Merge() and Tkapp_Call() routines.
1233
1234- Several changes were made to cStringIO to make it compatible with
1235 the file-like object interface and with StringIO. If operations are
1236 performed on a closed object, an exception is raised. The truncate
1237 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001238 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001239
1240- There were many changes made to the linuxaudiodev module and its
1241 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001242 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001243
1244 Note that this module is named poorly, because it should work
1245 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001246 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001247
1248 The module now raises exceptions when errors occur instead of
1249 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1250 audio) and defines a getptr() method that calls the
1251 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1252
1253- The library_version attribute, introduced in an earlier beta, was
1254 removed because it can not be supported with early versions of the C
1255 readline library, which provides no way to determine the version at
1256 compile-time.
1257
1258- The binascii module is now enabled on Win64.
1259
Tim Peters46446d62000-10-09 21:19:31 +00001260- tokenize.py no longer suffers "recursion depth" errors when parsing
1261 programs with very long string literals.
1262
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001263Internals
1264
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001265- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001266 which is called when the interpreter starts up to determine where
1267 the standard library is installed. These vulnerabilities affect all
1268 previous versions of Python and can be exploited by setting very
1269 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1270 setuid Python script, although use of the wrapper in
1271 Misc/setuid-prog.c will eliminate the vulnerability.
1272
1273- Fixed garbage collection bugs in instance creation that were
1274 triggered when errors occurred during initialization. The solution,
1275 applied in cPickle and in PyInstance_New(), is to call
1276 PyObject_GC_Init() after the initialization of the object's
1277 container attributes is complete.
1278
1279- pyexpat adds definitions of PyModule_AddStringConstant and
1280 PyModule_AddObject if the Python version is less than 2.0, which
1281 provides compatibility with PyXML on Python 1.5.2.
1282
1283- If the platform has a bogus definition for LONG_BIT (the number of
1284 bits in a long), an error will be reported at compile time.
1285
1286- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1287 collection crashes and possibly other, unreported crashes.
1288
1289- Fixed a memory leak in _PyUnicode_Fini().
1290
1291Build issues
1292
1293- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001294 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001295 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001296
1297- The mmap.PAGESIZE constant is now initialized using sysconf when
1298 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1299
1300- The md5 file should now compile on all platforms.
1301
1302- The select module now compiles on platforms that do not define
1303 POLLRDNORM and related constants.
1304
1305- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001306 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001307
Jeremy Hylton10921202000-10-09 18:34:12 +00001308- BeOS: A number of changes were made to the build and installation
1309 process. ar-fake now operates on a directory of object files.
1310 dl_export.h is gone, and its macros now appear on the mwcc command
1311 line during build on PPC BeOS.
1312
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001313- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001314 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001315
1316- Cygwin: Support for shared libraries, Tkinter, and sockets.
1317
1318- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1319
1320Tools and other miscellany
1321
1322- Removed debugging prints from main used with freeze.
1323
Tim Peters46446d62000-10-09 21:19:31 +00001324- IDLE auto-indent no longer crashes when it encounters Unicode
1325 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001326
1327What's new in 2.0 beta 2 (since beta 1)?
1328========================================
1329
1330Core language, builtins, and interpreter
1331
Tim Peters482c0212000-09-26 06:33:09 +00001332- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001333 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001334
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001335- Add -h and -V command line options to print the usage message and
1336 Python version number and exit immediately.
1337
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001338- eval() and exec accept Unicode objects as code parameters.
1339
1340- getattr() and setattr() now also accept Unicode objects for the
1341 attribute name, which are converted to strings using the default
1342 encoding before lookup.
1343
1344- Multiplication on string and Unicode now does proper bounds
1345 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1346 string is too long."
1347
1348- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001349 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001350
Jeremy Hylton1b618592000-09-26 05:32:36 +00001351
1352Standard library and extensions
1353
Guido van Rossum5b08f132001-04-16 02:05:23 +00001354- socket module: the OpenSSL code now adds support for RAND_status()
1355 and EGD (Entropy Gathering Device).
1356
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001357- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001358 argument checking; it still takes no arguments.
1359
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001360- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001361
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001362- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001363
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001364- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001365
1366- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001367 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001368
1369- copy: Copy Unicode objects atomically.
1370
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001371- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001372
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001373- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001374
Fred Drake67233bc2000-09-26 16:40:27 +00001375- dbm: Add get() and setdefault() methods to dbm object. Add constant
1376 `library' to module that names the library used. Added doc strings
1377 and method names to error messages. Uses configure to determine
1378 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1379 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001380
1381- distutils: Update to version 0.9.3.
1382
1383- dl: Add several dl.RTLD_ constants.
1384
1385- fpectl: Now supported on FreeBSD.
1386
1387- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1388 found by the collector will be saved in gc.garbage. This is useful
1389 for debugging a program that creates reference cycles.
1390
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001391- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001392 of HTTP class. Do not close socket on zero-length response. Do not
1393 crash when server sends invalid content-length header.
1394
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001395- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001396
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001397- marshal: When reading a short, sign-extend on platforms where shorts
1398 are bigger than 16 bits. When reading a long, repair the unportable
1399 sign extension that was being done for 64-bit machines. (It assumed
1400 that signed right shift sign-extends.)
1401
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001402- operator: Add contains(), invert(), __invert__() as aliases for
1403 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001404
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001405- os: Add support for popen2() and popen3() on all platforms where
1406 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001407
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001408- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001409 clicking on a file in Explorer (or passing the file name to the
1410 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001411
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001412- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001413 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001414
1415- pickle: Now raises ValueError when an invalid pickle that contains
1416 a non-string repr where a string repr was expected. This behavior
1417 matches cPickle.
1418
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001419- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001420
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001421- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001422
1423- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001424 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001425 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001426
1427- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001428 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001429
1430- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001431 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001432 few cycles during startup since the first call to
1433 setdefaultencoding() will initialize the codec registry and the
1434 encodings package.
1435
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001436- socket: Support for size hint in readlines() method of object returned
1437 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001438
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001439- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001440 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001441 is followed by whitespace.
1442
Tim Petersa3a3a032000-11-30 05:22:44 +00001443- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001444
1445- struct: Check ranges for bytes and shorts.
1446
1447- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001448 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001449
1450- Tkinter: Image objects are now guaranteed to have unique ids. Set
1451 event.delta to zero if Tk version doesn't support mousewheel.
1452 Removed some debugging prints.
1453
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001454- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001455
Fred Drake67233bc2000-09-26 16:40:27 +00001456- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001457 which works around a bug in Norton AntiVirus 2000 that leads directly
1458 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001459
1460- xml: New version detection code allows PyXML to override standard
1461 XML package if PyXML version is greater than 0.6.1.
1462
Fred Drake64bb3802000-09-26 16:21:35 +00001463- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1464 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1465 tree only for nodes which are sufficiently interesting to a specific
1466 application. Does not provide the HTML-specific extensions. Still
1467 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001468
Fred Drake64bb3802000-09-26 16:21:35 +00001469- xml.sax: SAX 2 support for Python, including all the handler
1470 interfaces needed to process XML 1.0 compliant XML. Some
1471 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001472
Fred Drake64bb3802000-09-26 16:21:35 +00001473- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1474 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001475
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001476
Jeremy Hylton1b618592000-09-26 05:32:36 +00001477C API
1478
1479- Add three new convenience functions for module initialization --
1480 PyModule_AddObject(), PyModule_AddIntConstant(), and
1481 PyModule_AddStringConstant().
1482
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001483- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001484 removed and add #error to Python.h if NULL isn't defined after
1485 #include of stdio.h.
1486
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001487- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001488 backwards compatibility (at the source level) with old extensions.
1489
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001490- A wrapper API was added for signal() and sigaction(). Instead of
1491 either function, always use PyOS_getsig() to get a signal handler
1492 and PyOS_setsig() to set one. A new convenience typedef
1493 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001494
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001495- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001496 internal data buffer and size of a string object -- or the default
1497 encoded version of a Unicode object.
1498
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001499- PyString_Size() and PyString_AsString() accept Unicode objects.
1500
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001501- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001502 exists). INT_MAX and LONG_MAX will always be defined, even if
1503 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001504
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001505- PyFloat_FromString takes a second argument, pend, that was
1506 effectively useless. It is now officially useless but preserved for
1507 backwards compatibility. If the pend argument is not NULL, *pend is
1508 set to NULL.
1509
1510- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1511 for the attribute name. See note on getattr() above.
1512
1513- A few bug fixes to argument processing for Unicode.
1514 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1515 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1516 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001517 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001518
1519- Py_BuildValue accepts B format (for bgen-generated code).
1520
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001521
Jeremy Hylton1b618592000-09-26 05:32:36 +00001522Internals
1523
1524- On Unix, fix code for finding Python installation directory so that
1525 it works when argv[0] is a relative path.
1526
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001527- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001528 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001529 rather than by generating a copy of the object.
1530
Tim Peters482c0212000-09-26 06:33:09 +00001531- Several of the internal Unicode tables are much smaller now, and
1532 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001533
Jeremy Hylton97693b02000-09-26 17:42:51 +00001534- In the garbage collector: Fixed bug in collection of tuples. Fixed
1535 bug that caused some instances to be removed from the container set
1536 while they were still live. Fixed parsing in gc.set_debug() for
1537 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001538
1539- Fixed refcount problem in instance deallocation that only occurred
1540 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1541
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001542- On Windows, getpythonregpath is now protected against null data in
1543 registry key.
1544
1545- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001546 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001547
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001548
Jeremy Hylton1b618592000-09-26 05:32:36 +00001549Build and platform-specific issues
1550
1551- Better support of GNU Pth via --with-pth configure option.
1552
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001553- Python/C API now properly exposed to dynamically-loaded extension
1554 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001555
1556- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1557 Don't define MS_SYNC to be zero when it is undefined. Added missing
1558 prototypes in posixmodule.c.
1559
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001560- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001561 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001562
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001563- Fix largefile support on older NetBSD systems and OpenBSD by adding
1564 define for TELL64.
1565
1566
1567Tools and other miscellany
1568
1569- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1570
1571- freeze: The modulefinder now works with 2.0 opcodes.
1572
Tim Petersa3a3a032000-11-30 05:22:44 +00001573- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001574 Move hackery of sys.argv until after the Tk instance has been
1575 created, which allows the application-specific Tkinter
1576 initialization to be executed if present; also pass an explicit
1577 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001578
Jeremy Hylton1b618592000-09-26 05:32:36 +00001579
1580What's new in 2.0 beta 1?
1581=========================
1582
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001583Source Incompatibilities
1584------------------------
1585
1586None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1587such as single-argument append(), connect() and bind(), and changes to
1588str(long) and repr(float).
1589
1590
1591Binary Incompatibilities
1592------------------------
1593
1594- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1595with Python 2.0; these extensions will have to be rebuilt for Python
15962.0.
1597
1598- On Windows, attempting to import a third party extension built for
1599Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1600can do about this. Check your PYTHONPATH environment variable!
1601
1602- Python bytecode files (*.pyc and *.pyo) are not compatible between
1603releases.
1604
1605
1606Overview of Changes Since 1.6
1607-----------------------------
1608
1609There are many new modules (including brand new XML support through
1610the xml package, and i18n support through the gettext module); a list
1611of all new modules is included below. Lots of bugs have been fixed.
1612
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001613The process for making major new changes to the language has changed
1614since Python 1.6. Enhancements must now be documented by a Python
1615Enhancement Proposal (PEP) before they can be accepted.
1616
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001617There are several important syntax enhancements, described in more
1618detail below:
1619
1620 - Augmented assignment, e.g. x += 1
1621
1622 - List comprehensions, e.g. [x**2 for x in range(10)]
1623
1624 - Extended import statement, e.g. import Module as Name
1625
1626 - Extended print statement, e.g. print >> file, "Hello"
1627
1628Other important changes:
1629
1630 - Optional collection of cyclical garbage
1631
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001632Python Enhancement Proposal (PEP)
1633---------------------------------
1634
1635PEP stands for Python Enhancement Proposal. A PEP is a design
1636document providing information to the Python community, or describing
1637a new feature for Python. The PEP should provide a concise technical
1638specification of the feature and a rationale for the feature.
1639
1640We intend PEPs to be the primary mechanisms for proposing new
1641features, for collecting community input on an issue, and for
1642documenting the design decisions that have gone into Python. The PEP
1643author is responsible for building consensus within the community and
1644documenting dissenting opinions.
1645
1646The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001647
1648Augmented Assignment
1649--------------------
1650
1651This must have been the most-requested feature of the past years!
1652Eleven new assignment operators were added:
1653
Guido van Rossume905e952000-09-05 12:42:46 +00001654 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001655
1656For example,
1657
1658 A += B
1659
1660is similar to
1661
1662 A = A + B
1663
1664except that A is evaluated only once (relevant when A is something
1665like dict[index].attr).
1666
1667However, if A is a mutable object, A may be modified in place. Thus,
1668if A is a number or a string, A += B has the same effect as A = A+B
1669(except A is only evaluated once); but if a is a list, A += B has the
1670same effect as A.extend(B)!
1671
1672Classes and built-in object types can override the new operators in
1673order to implement the in-place behavior; the not-in-place behavior is
1674used automatically as a fallback when an object doesn't implement the
1675in-place behavior. For classes, the method name is derived from the
1676method name for the corresponding not-in-place operator by inserting
1677an 'i' in front of the name, e.g. __iadd__ implements in-place
1678__add__.
1679
1680Augmented assignment was implemented by Thomas Wouters.
1681
1682
1683List Comprehensions
1684-------------------
1685
1686This is a flexible new notation for lists whose elements are computed
1687from another list (or lists). The simplest form is:
1688
1689 [<expression> for <variable> in <sequence>]
1690
Guido van Rossum56db0952000-09-06 23:34:25 +00001691For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001692This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001693
1694You can also add a condition:
1695
1696 [<expression> for <variable> in <sequence> if <condition>]
1697
1698For example, [w for w in words if w == w.lower()] would yield the list
1699of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001700than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001701
1702You can also have nested for loops and more than one 'if' clause. For
1703example, here's a function that flattens a sequence of sequences::
1704
1705 def flatten(seq):
1706 return [x for subseq in seq for x in subseq]
1707
1708 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1709
1710This prints
1711
1712 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1713
1714List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001715Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001716
1717
1718Extended Import Statement
1719-------------------------
1720
1721Many people have asked for a way to import a module under a different
1722name. This can be accomplished like this:
1723
1724 import foo
1725 bar = foo
1726 del foo
1727
1728but this common idiom gets old quickly. A simple extension of the
1729import statement now allows this to be written as follows:
1730
1731 import foo as bar
1732
1733There's also a variant for 'from ... import':
1734
1735 from foo import bar as spam
1736
1737This also works with packages; e.g. you can write this:
1738
1739 import test.regrtest as regrtest
1740
1741Note that 'as' is not a new keyword -- it is recognized only in this
1742context (this is only possible because the syntax for the import
1743statement doesn't involve expressions).
1744
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001745Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001746
1747
1748Extended Print Statement
1749------------------------
1750
1751Easily the most controversial new feature, this extension to the print
1752statement adds an option to make the output go to a different file
1753than the default sys.stdout.
1754
1755For example, to write an error message to sys.stderr, you can now
1756write:
1757
1758 print >> sys.stderr, "Error: bad dog!"
1759
1760As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001761evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001762
1763 print >> None, "Hello world"
1764
1765is equivalent to
1766
1767 print "Hello world"
1768
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001769Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001770
1771
1772Optional Collection of Cyclical Garbage
1773---------------------------------------
1774
1775Python is now equipped with a garbage collector that can hunt down
1776cyclical references between Python objects. It's no replacement for
1777reference counting; in fact, it depends on the reference counts being
1778correct, and decides that a set of objects belong to a cycle if all
1779their reference counts can be accounted for from their references to
1780each other. This devious scheme was first proposed by Eric Tiedemann,
1781and brought to implementation by Neil Schemenauer.
1782
1783There's a module "gc" that lets you control some parameters of the
1784garbage collection. There's also an option to the configure script
1785that lets you enable or disable the garbage collection. In 2.0b1,
1786it's on by default, so that we (hopefully) can collect decent user
1787experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001788performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001789off by default in the final 2.0 release.
1790
1791
1792Smaller Changes
1793---------------
1794
1795A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1796map(None, seq1, seq2, ...) when the sequences have the same length;
1797i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1798the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001799zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001800
1801sys.version_info is a tuple (major, minor, micro, level, serial).
1802
1803Dictionaries have an odd new method, setdefault(key, default).
1804dict.setdefault(key, default) returns dict[key] if it exists; if not,
1805it sets dict[key] to default and returns that value. Thus:
1806
1807 dict.setdefault(key, []).append(item)
1808
1809does the same work as this common idiom:
1810
1811 if not dict.has_key(key):
1812 dict[key] = []
1813 dict[key].append(item)
1814
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001815There are two new variants of SyntaxError that are raised for
1816indentation-related errors: IndentationError and TabError.
1817
1818Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1819escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001820
1821The limits on the size of expressions and file in Python source code
1822have been raised from 2**16 to 2**32. Previous versions of Python
1823were limited because the maximum argument size the Python VM accepted
1824was 2**16. This limited the size of object constructor expressions,
1825e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1826limit was raised thanks to a patch by Charles Waldman that effectively
1827fixes the problem. It is now much more likely that you will be
1828limited by available memory than by an arbitrary limit in Python.
1829
1830The interpreter's maximum recursion depth can be modified by Python
1831programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1832limit is the maximum number of recursive calls that can be made by
1833Python code. The limit exists to prevent infinite recursion from
1834overflowing the C stack and causing a core dump. The default value is
18351000. The maximum safe value for a particular platform can be found
1836by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001837
1838New Modules and Packages
1839------------------------
1840
1841atexit - for registering functions to be called when Python exits.
1842
1843imputil - Greg Stein's alternative API for writing custom import
1844hooks.
1845
1846pyexpat - an interface to the Expat XML parser, contributed by Paul
1847Prescod.
1848
1849xml - a new package with XML support code organized (so far) in three
1850subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1851would fill a volume. There's a special feature whereby a
1852user-installed package named _xmlplus overrides the standard
1853xmlpackage; this is intended to give the XML SIG a hook to distribute
1854backwards-compatible updates to the standard xml package.
1855
1856webbrowser - a platform-independent API to launch a web browser.
1857
1858
Guido van Rossume905e952000-09-05 12:42:46 +00001859Changed Modules
1860---------------
1861
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001862array -- new methods for array objects: count, extend, index, pop, and
1863remove
1864
1865binascii -- new functions b2a_hex and a2b_hex that convert between
1866binary data and its hex representation
1867
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001868calendar -- Many new functions that support features including control
1869over which day of the week is the first day, returning strings instead
1870of printing them. Also new symbolic constants for days of week,
1871e.g. MONDAY, ..., SUNDAY.
1872
1873cgi -- FieldStorage objects have a getvalue method that works like a
1874dictionary's get method and returns the value attribute of the object.
1875
1876ConfigParser -- The parser object has new methods has_option,
1877remove_section, remove_option, set, and write. They allow the module
1878to be used for writing config files as well as reading them.
1879
1880ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001881optionally support the RFC 959 REST command.
1882
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001883gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001884
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001885httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1886the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001887
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001888locale -- implement getdefaultlocale for Win32 and Macintosh
1889
1890marshal -- no longer dumps core when marshaling deeply nested or
1891recursive data structures
1892
1893os -- new functions isatty, seteuid, setegid, setreuid, setregid
1894
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001895os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1896support under Unix.
1897
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001898os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001899
1900os.path -- fix semantics of os.path.commonprefix
1901
1902smtplib -- support for sending very long messages
1903
1904socket -- new function getfqdn()
1905
1906readline -- new functions to read, write and truncate history files.
1907The readline section of the library reference manual contains an
1908example.
1909
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001910select -- add interface to poll system call
1911
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001912shutil -- new copyfileobj function
1913
1914SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1915HTTP server.
1916
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001917Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001918
1919urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001920e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001921
1922whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001923
1924
1925Obsolete Modules
1926----------------
1927
1928None. However note that 1.6 made a whole slew of modules obsolete:
1929stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1930poly, zmod, strop, util, whatsound.
1931
1932
1933Changed, New, Obsolete Tools
1934----------------------------
1935
Tim Peters8b092332000-09-05 20:15:25 +00001936None.
Guido van Rossume905e952000-09-05 12:42:46 +00001937
1938
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001939C-level Changes
1940---------------
1941
1942Several cleanup jobs were carried out throughout the source code.
1943
1944All C code was converted to ANSI C; we got rid of all uses of the
1945Py_PROTO() macro, which makes the header files a lot more readable.
1946
1947Most of the portability hacks were moved to a new header file,
1948pyport.h; several other new header files were added and some old
1949header files were removed, in an attempt to create a more rational set
1950of header files. (Few of these ever need to be included explicitly;
1951they are all included by Python.h.)
1952
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001953Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001954and Win64, especially for the new Intel Itanium processor. Mick also
1955added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001956
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001957The C APIs to return an object's size have been update to consistently
1958use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1959previous versions, the abstract interfaces used PyXXX_Length and the
1960concrete interfaces used PyXXX_Size. The old names,
1961e.g. PyObject_Length, are still available for backwards compatibility
1962at the API level, but are deprecated.
1963
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001964The PyOS_CheckStack function has been implemented on Windows by
1965Fredrik Lundh. It prevents Python from failing with a stack overflow
1966on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001967
1968The GC changes resulted in creation of two new slots on object,
1969tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001970the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001971
1972The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001973C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001974
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001975PyErr_Format has been updated to automatically calculate the size of
1976the buffer needed to hold the formatted result string. This change
1977prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001978
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001979New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001980
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001981PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1982that are the same as their non-Ex counterparts except they take an
1983extra flag argument that tells them to close the file when done.
1984
1985XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001986
Tim Peters8b092332000-09-05 20:15:25 +00001987
1988Windows Changes
1989---------------
1990
1991New popen2/popen3/peopen4 in os module (see Changed Modules above).
1992
1993os.popen is much more usable on Windows 95 and 98. See Microsoft
1994Knowledge Base article Q150956. The Win9x workaround described there
1995is implemented by the new w9xpopen.exe helper in the root of your
1996Python installation. Note that Python uses this internally; it is not
1997a standalone program.
1998
1999Administrator privileges are no longer required to install Python
2000on Windows NT or Windows 2000. If you have administrator privileges,
2001Python's registry info will be written under HKEY_LOCAL_MACHINE.
2002Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002003under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002004uses of Python, but will prevent some advanced uses from working
2005(for example, running a Python script as an NT service, or possibly
2006from CGI).
2007
2008[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2009installer; instead, it installs the needed Tcl/Tk files directly in the
2010Python directory. If you already have a Tcl/Tk installation, this
2011wastes some disk space (about 4 Megs) but avoids problems with
2012conflicting Tcl/Tk installations, and makes it much easier for Python
2013to ensure that Tcl/Tk can find all its files.
2014
2015[This was new in 1.6] The Windows installer now installs by default in
2016\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2017
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002018
2019Updates to the changes between 1.5.2 and 1.6
2020--------------------------------------------
2021
2022The 1.6 NEWS file can't be changed after the release is done, so here
2023is some late-breaking news:
2024
2025New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2026and changes to getlocale() and setlocale().
2027
2028The new module is now enabled per default.
2029
2030It is not true that the encodings codecs cannot be used for normal
2031strings: the string.encode() (which is also present on 8-bit strings
2032!) allows using them for 8-bit strings too, e.g. to convert files from
2033cp1252 (Windows) to latin-1 or vice-versa.
2034
2035Japanese codecs are available from Tamito KAJIYAMA:
2036http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2037
2038
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002039======================================================================