blob: 344949c2b0eaed5598ee422218dc374a2d58ce66 [file] [log] [blame]
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
Fred Drake960fdf92001-07-20 18:38:26 +0000152- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
153 were added to the string module. These a locale-indenpendent
154 constants, unlike letters, lowercase, and uppercase. These are now
155 use in appropriate locations in the standard library.
156
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000157- The flags used in dlopen calls can now be configured using
158 sys.setdlopenflags and queried using sys.getdlopenflags.
159
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000160- Fredrik Lundh's xmlrpclib is now a standard library module. This
161 provides full client-side XML-RPC support. In addition,
162 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
163 one asyncore-based). Thanks to Eric Raymond for the documentation.
164
Guido van Rossum643d3912001-07-05 14:46:25 +0000165- The xrange() object is simplified: it no longer supports slicing,
166 repetition, comparisons, efficient 'in' checking, the tolist()
167 method, or the start, stop and step attributes. See PEP 260.
168
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000169- A new function fnmatch.filter to filter lists of file names was added.
170
Barry Warsawffd674d2001-05-22 16:00:10 +0000171- calendar.py uses month and day names based on the current locale.
172
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000173- strop is now *really* obsolete (this was announced before with 1.6),
174 and issues DeprecationWarning when used (except for the four items
175 that are still imported into string.py).
176
Tim Petersa814db52001-05-14 07:05:58 +0000177- Cookie.py now sorts key+value pairs by key in output strings.
178
179- pprint.isrecursive(object) didn't correctly identify recursive objects.
180 Now it does.
181
Tim Peters95b3f782001-05-14 18:39:41 +0000182- pprint functions now much faster for large containers (tuple, list, dict).
183
Tim Peters7b9542a2001-06-10 23:40:19 +0000184- New 'q' and 'Q' format codes in the struct module, corresponding to C
185 types "long long" and "unsigned long long" (on Windows, __int64). In
186 native mode, these can be used only when the platform C compiler supports
187 these types (when HAVE_LONG_LONG is #define'd by the Python config
188 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000189 In standard mode, 'q' and 'Q' are supported on all platforms, and are
190 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000191
Guido van Rossum83213cc2001-06-12 16:48:52 +0000192- The site module installs a new built-in function 'help' that invokes
193 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
194 it displays a message reminding the user to use 'help()' or
195 'help(object)'.
196
Tim Petersa814db52001-05-14 07:05:58 +0000197Tests
198
199- New test_mutants.py runs dict comparisons where the key and value
200 comparison operators mutute the dicts randomly during comparison. This
201 rapidly causes Python to crash under earlier releases (not for the faint
202 of heart: it can also cause Win9x to freeze or reboot!).
203
204- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000205 pprint.isreadable() return sensible results. Also verifies that simple
206 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000207
Tim Peters58e0a8c2001-05-14 22:32:33 +0000208New platforms
209
210- Python should compile and run out of the box using the Borland C
211 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000212
Tim Peters4324aa32001-05-28 22:30:08 +0000213C API
214
215- Removed the unused last_is_sticky argument from the internal
216 _PyTuple_Resize(). If this affects you, you were cheating.
217
218
Guido van Rossum55a78992001-07-17 17:22:32 +0000219======================================================================
220
221
Guido van Rossumffe13be2001-04-16 18:46:45 +0000222What's New in Python 2.1 (final)?
223=================================
224
225We only changed a few things since the last release candidate, all in
226Python library code:
227
228- A bug in the locale module was fixed that affected locales which
229 define no grouping for numeric formatting.
230
231- A few bugs in the weakref module's implementations of weak
232 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
233 and the test suite was updated to check for these bugs.
234
235- An old bug in the os.path.walk() function (introduced in Python
236 2.0!) was fixed: a non-existent file would cause an exception
237 instead of being ignored.
238
239- Fixed a few bugs in the new symtable module found by Neil Norwitz's
240 PyChecker.
241
242
Guido van Rossum5b08f132001-04-16 02:05:23 +0000243What's New in Python 2.1c2?
244===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000245
Guido van Rossum5b08f132001-04-16 02:05:23 +0000246A flurry of small changes, and one showstopper fixed in the nick of
247time made it necessary to release another release candidate. The list
248here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000249
Guido van Rossum5b08f132001-04-16 02:05:23 +0000250Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000251
Guido van Rossum5b08f132001-04-16 02:05:23 +0000252- Tim discovered a nasty bug in the dictionary code, caused by
253 PyDict_Next() calling dict_resize(), and the GC code's use of
254 PyDict_Next() violating an assumption in dict_items(). This was
255 fixed with considerable amounts of band-aid, but the net effect is a
256 saner and more robust implementation.
257
258- Made a bunch of symbols static that were accidentally global.
259
260Build and Ports
261
262- The setup.py script didn't check for a new enough version of zlib
263 (1.1.3 is needed). Now it does.
264
265- Changed "make clean" target to also remove shared libraries.
266
267- Added a more general warning about the SGI Irix optimizer to README.
268
269Library
270
271- Fix a bug in urllib.basejoin("http://host", "../file.html") which
272 omitted the slash between host and file.html.
273
274- The mailbox module's _Mailbox class contained a completely broken
275 and undocumented seek() method. Ripped it out.
276
277- Fixed a bunch of typos in various library modules (urllib2, smtpd,
278 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
279
280- Fixed a few last-minute bugs in unittest.
281
282Extensions
283
284- Reverted the patch to the OpenSSL code in socketmodule.c to support
285 RAND_status() and the EGD, and the subsequent patch that tried to
286 fix it for pre-0.9.5 versions; the problem with the patch is that on
287 some systems it issues a warning whenever socket is imported, and
288 that's unacceptable.
289
290Tests
291
292- Fixed the pickle tests to work with "import test.test_pickle".
293
294- Tweaked test_locale.py to actually run the test Windows.
295
296- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
297 not "wb" (which is not a valid mode at all).
298
299- Fix pstats browser crashes. Import readline if it exists to make
300 the user interface nicer.
301
302- Add "import thread" to the top of test modules that import the
303 threading module (test_asynchat and test_threadedtempfile). This
304 prevents test failures caused by a broken threading module resulting
305 from a previously caught failed import.
306
307- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
308 needed on some platforms (e.g. Solaris 8) when the tests are run
309 twice in succession.
310
311- Skip rather than fail test_sunaudiodev if no audio device is found.
312
313
314What's New in Python 2.1c1?
315===========================
316
317This list was significantly updated when 2.1c2 was released; the 2.1c1
318release didn't mention most changes that were actually part of 2.1c1:
319
320Legal
321
322- Copyright was assigned to the Python Software Foundation (PSF) and a
323 PSF license (very similar to the CNRI license) was added.
324
325- The CNRI copyright notice was updated to include 2001.
326
327Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000328
Guido van Rossumc9932722001-04-12 02:31:27 +0000329- After a public outcry, assignment to __debug__ is no longer illegal;
330 instead, a warning is issued. It will become illegal in 2.2.
331
Guido van Rossum5b08f132001-04-16 02:05:23 +0000332- Fixed a core dump with "%#x" % 0, and changed the semantics so that
333 "%#x" now always prepends "0x", even if the value is zero.
334
335- Fixed some nits in the bytecode compiler.
336
337- Fixed core dumps when calling certain kinds of non-functions.
338
339- Fixed various core dumps caused by reference count bugs.
340
341Build and Ports
342
343- Use INSTALL_SCRIPT to install script files.
344
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000345- New port: SCO Unixware 7, by Billy G. Allie.
346
Guido van Rossum5b08f132001-04-16 02:05:23 +0000347- Updated RISCOS port.
348
349- Updated BeOS port and notes.
350
351- Various other porting problems resolved.
352
353Library
354
355- The TERMIOS and SOCKET modules are now truly obsolete and
356 unnecessary. Their symbols are incorporated in the termios and
357 socket modules.
358
359- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
360 better tests for pickling.
361
362- threading: make Condition.wait() robust against KeyboardInterrupt.
363
364- zipfile: add support to zipfile to support opening an archive
365 represented by an open file rather than a file name. Fix bug where
366 the archive was not properly closed. Fixed a bug in this bugfix
367 where flush() was called for a read-only file.
368
369- imputil: added an uninstall() method to the ImportManager.
370
371- Canvas: fixed bugs in lower() and tkraise() methods.
372
373- SocketServer: API change (added overridable close_request() method)
374 so that the TCP server can explicitly close the request.
375
376- pstats: Eric Raymond added a simple interactive statistics browser,
377 invoked when the module is run as a script.
378
379- locale: fixed a problem in format().
380
381- webbrowser: made it work when the BROWSER environment variable has a
382 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
383 KDE 2. Fixed some other nits.
384
385- unittest: changes to allow using a different exception than
386 AssertionError, and added a few more function aliases. Some other
387 small changes.
388
389- urllib, urllib2: fixed redirect problems and a coupleof other nits.
390
391- asynchat: fixed a critical bug in asynchat that slipped through the
392 2.1b2 release. Fixed another rare bug.
393
394- Fix some unqualified except: clauses (always a bad code example).
395
396XML
397
398- pyexpat: new API get_version_string().
399
400- Fixed some minidom bugs.
401
402Extensions
403
404- Fixed a core dump in _weakref. Removed the weakref.mapping()
405 function (it adds nothing to the API).
406
407- Rationalized the use of header files in the readline module, to make
408 it compile (albeit with some warnings) with the very recent readline
409 4.2, without breaking for earlier versions.
410
411- Hopefully fixed a buffering problem in linuxaudiodev.
412
413- Attempted a fix to make the OpenSSL support in the socket module
414 work again with pre-0.9.5 versions of OpenSSL.
415
416Tests
417
418- Added a test case for asynchat and asyncore.
419
420- Removed coupling between tests where one test failing could break
421 another.
422
423Tools
424
425- Ping added an interactive help browser to pydoc, fixed some nits
426 in the rest of the pydoc code, and added some features to his
427 inspect module.
428
429- An updated python-mode.el version 4.1 which integrates Ken
430 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
431 much nicer in XEmacs and Emacs. When stepping through your program
432 with pdb, in either the shell window or the *Python* window, the
433 source file and line will be tracked by an arrow. Very cool!
434
435- IDLE: syntax warnings in interactive mode are changed into errors.
436
437- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000438 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000439
440- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000441
Barry Warsaw11e89c72001-04-11 20:37:57 +0000442
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000443What's New in Python 2.1 beta 2?
444================================
445
Guido van Rossum053ae352001-03-22 14:17:21 +0000446(Unlisted are many fixed bugs, more documentation, etc.)
447
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000448Core language, builtins, and interpreter
449
Guido van Rossum053ae352001-03-22 14:17:21 +0000450- The nested scopes work (enabled by "from __future__ import
451 nested_scopes") is completed; in particular, the future now extends
452 into code executed through exec, eval() and execfile(), and into the
453 interactive interpreter.
454
455- When calling a base class method (e.g. BaseClass.__init__(self)),
456 this is now allowed even if self is not strictly spoken a class
457 instance (e.g. when using metaclasses or the Don Beaudry hook).
458
459- Slice objects are now comparable but not hashable; this prevents
460 dict[:] from being accepted but meaningless.
461
462- Complex division is now calculated using less braindead algorithms.
463 This doesn't change semantics except it's more likely to give useful
464 results in extreme cases. Complex repr() now uses full precision
465 like float repr().
466
467- sgmllib.py now calls handle_decl() for simple <!...> declarations.
468
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000469- It is illegal to assign to the name __debug__, which is set when the
470 interpreter starts. It is effectively a compile-time constant.
471
472- A warning will be issued if a global statement for a variable
473 follows a use or assignment of that variable.
474
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000475Standard library
476
Guido van Rossum053ae352001-03-22 14:17:21 +0000477- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
478 inspired by JUnit), is now part of the standard library. You now
479 have a choice of two testing frameworks: unittest requires you to
480 write testcases as separate code, doctest gathers them from
481 docstrings. Both approaches have their advantages and
482 disadvantages.
483
484- A new module Tix was added, which wraps the Tix extension library
485 for Tk. With that module, it is not necessary to statically link
486 Tix with _tkinter, since Tix will be loaded with Tcl's "package
487 require" command. See Demo/tix/.
488
489- tzparse.py is now obsolete.
490
491- In gzip.py, the seek() and tell() methods are removed -- they were
492 non-functional anyway, and it's better if callers can test for their
493 existence with hasattr().
494
495Python/C API
496
497- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
498 that's already in the dictionary during a PyDict_Next() iteration.
499 This used to fail occasionally when a dictionary resize operation
500 could be triggered that would rehash all the keys. All other
501 modifications to the dictionary are still off-limits during a
502 PyDict_Next() iteration!
503
504- New extended APIs related to passing compiler variables around.
505
506- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
507 implement isinstance() and issubclass().
508
509- Py_BuildValue() now has a "D" conversion to create a Python complex
510 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000511
Fred Drake4e262a92001-03-22 18:26:47 +0000512- Extensions types which support weak references must now set the
513 field allocated for the weak reference machinery to NULL themselves;
514 this is done to avoid the cost of checking each object for having a
515 weakly referencable type in PyObject_INIT(), since most types are
516 not weakly referencable.
517
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000518- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
519 free variables and cell variables to and from the frame's f_locals.
520
521- Variants of several functions defined in pythonrun.h have been added
522 to support the nested_scopes future statement. The variants all end
523 in Flags and take an extra argument, a PyCompilerFlags *; examples:
524 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
525 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000526 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000527
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000528Distutils
529
530- the sdist command now writes a PKG-INFO file, as described in PEP 241,
531 into the release tree.
532
Tim Peters0e57abf2001-05-02 07:39:38 +0000533- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000534 (an uninstaller, more customization of the installer's display)
535
536- from Jack Jansen: added Mac-specific code to generate a dialog for
537 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000538 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000539 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000540
541- added 'platforms' and 'keywords' to the set of metadata that can be
542 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000543
544- applied patches from Jason Tishler to make the compiler class work with
545 Cygwin.
546
547
Tim Peters2fe289a2001-03-01 22:19:38 +0000548What's New in Python 2.1 beta 1?
549================================
Tim Petersd66595f2001-02-04 03:09:53 +0000550
551Core language, builtins, and interpreter
552
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000553- Following an outcry from the community about the amount of code
554 broken by the nested scopes feature introduced in 2.1a2, we decided
555 to make this feature optional, and to wait until Python 2.2 (or at
556 least 6 months) to make it standard. The option can be enabled on a
557 per-module basis by adding "from __future__ import nested_scopes" at
558 the beginning of a module (before any other statements, but after
559 comments and an optional docstring). See PEP 236 (Back to the
560 __future__) for a description of the __future__ statement. PEP 227
561 (Statically Nested Scopes) has been updated to reflect this change,
562 and to clarify the semantics in a number of endcases.
563
564- The nested scopes code, when enabled, has been hardened, and most
565 bugs and memory leaks in it have been fixed.
566
567- Compile-time warnings are now generated for a number of conditions
568 that will break or change in meaning when nested scopes are enabled:
569
570 - Using "from...import *" or "exec" without in-clause in a function
571 scope that also defines a lambda or nested function with one or
572 more free (non-local) variables. The presence of the import* or
573 bare exec makes it impossible for the compiler to determine the
574 exact set of local variables in the outer scope, which makes it
575 impossible to determine the bindings for free variables in the
576 inner scope. To avoid the warning about import *, change it into
577 an import of explicitly name object, or move the import* statement
578 to the global scope; to avoid the warning about bare exec, use
579 exec...in... (a good idea anyway -- there's a possibility that
580 bare exec will be deprecated in the future).
581
582 - Use of a global variable in a nested scope with the same name as a
583 local variable in a surrounding scope. This will change in
584 meaning with nested scopes: the name in the inner scope will
585 reference the variable in the outer scope rather than the global
586 of the same name. To avoid the warning, either rename the outer
587 variable, or use a global statement in the inner function.
588
Neil Schemenauera35c6882001-02-27 04:45:05 +0000589- An optional object allocator has been included. This allocator is
590 optimized for Python objects and should be faster and use less memory
591 than the standard system allocator. It is not enabled by default
592 because of possible thread safety problems. The allocator is only
593 protected by the Python interpreter lock and it is possible that some
594 extension modules require a thread safe allocator. The object
595 allocator can be enabled by providing the "--with-pymalloc" option to
596 configure.
597
Tim Petersd66595f2001-02-04 03:09:53 +0000598Standard library
599
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000600- pyexpat now detects the expat version if expat.h defines it. A
601 number of additional handlers are provided, which are only available
602 since expat 1.95. In addition, the methods SetParamEntityParsing and
603 GetInputContext of Parser objects are available with 1.95.x
604 only. Parser objects now provide the ordered_attributes and
605 specified_attributes attributes. A new module expat.model was added,
606 which offers a number of additional constants if 1.95.x is used.
607
608- xml.dom offers the new functions registerDOMImplementation and
609 getDOMImplementation.
610
611- xml.dom.minidom offers a toprettyxml method. A number of DOM
612 conformance issues have been resolved. In particular, Element now
613 has an hasAttributes method, and the handling of namespaces was
614 improved.
615
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000616- Ka-Ping Yee contributed two new modules: inspect.py, a module for
617 getting information about live Python code, and pydoc.py, a module
618 for interactively converting docstrings to HTML or text.
619 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000620 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000621 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
622 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000623
Tim Peters1eff7962001-03-01 02:31:33 +0000624- New library module difflib.py, primarily packaging the SequenceMatcher
625 class at the heart of the popular ndiff.py file-comparison tool.
626
627- doctest.py (a framework for verifying Python code examples in docstrings)
628 is now part of the std library.
629
Tim Petersd66595f2001-02-04 03:09:53 +0000630Windows changes
631
Guido van Rossume3955a82001-03-02 14:05:59 +0000632- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
633 small GUI that lets you browse the module docstrings using your
634 default web browser.
635
Tim Peters1eff7962001-03-01 02:31:33 +0000636- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
637 Platforms) is implemented. See
638
639 http://python.sourceforge.net/peps/pep-0235.html
640
641 for full details, especially the "Current Lower-Left Semantics" section.
642 The new Windows import rules are simpler than before:
643
644 A. If the PYTHONCASEOK environment variable exists, same as
645 before: silently accept the first case-insensitive match of any
646 kind; raise ImportError if none found.
647
648 B. Else search sys.path for the first case-sensitive match; raise
649 ImportError if none found.
650
651 The same rules have been implented on other platforms with case-
652 insensitive but case-preserving filesystems too (including Cygwin, and
653 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000654
Tim Peters25a9ce32001-02-19 07:06:36 +0000655- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
656 what it's supposed to do (and does do under NT and 2000) via direct
657 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000658 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000659 all Win9x systems before.
660
Tim Peters1eff7962001-03-01 02:31:33 +0000661- Build: Subproject _test (effectively) renamed to _testcapi.
662
Tim Peters2fe289a2001-03-01 22:19:38 +0000663New platforms
664
665- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
666 Thanks to Steven Majewski!
667
668- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
669 Tishler!
670
Guido van Rossum9089b272001-03-02 06:49:50 +0000671- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
672 Schwertberger! See RISCOS/README for more information -- it seems
673 that because of the bizarre filename conventions on RISCOS, no port
674 to that platform is easy. Note that the new variable os.endsep is
675 silently supported in order to make life easier on this platform,
676 but we don't advertise it because it's not worth for most folks to
677 care about RISCOS portability.
678
Tim Peters25a9ce32001-02-19 07:06:36 +0000679
Tim Petersd7b5e882001-01-25 03:36:26 +0000680What's New in Python 2.1 alpha 2?
681=================================
Tim Peters40ead762001-01-27 05:35:26 +0000682
Tim Petersd7b5e882001-01-25 03:36:26 +0000683Core language, builtins, and interpreter
684
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000685- Scopes nest. If a name is used in a function or class, but is not
686 local, the definition in the nearest enclosing function scope will
687 be used. One consequence of this change is that lambda statements
688 could reference variables in the namespaces where the lambda is
689 defined. In some unusual cases, this change will break code.
690
691 In all previous version of Python, names were resolved in exactly
692 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000693 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000694 function A is defined within a function B, the names bound in B are
695 not visible in A. The new rules make names bound in B visible in A,
696 unless A contains a name binding that hides the binding in B.
697
698 Section 4.1 of the reference manual describes the new scoping rules
699 in detail. The test script in Lib/test/test_scope.py demonstrates
700 some of the effects of the change.
701
702 The new rules will cause existing code to break if it defines nested
703 functions where an outer function has local variables with the same
704 name as globals or builtins used by the inner function. Example:
705
706 def munge(str):
707 def helper(x):
708 return str(x)
709 if type(str) != type(''):
710 str = helper(str)
711 return str.strip()
712
713 Under the old rules, the name str in helper() is bound to the
714 builtin function str(). Under the new rules, it will be bound to
715 the argument named str and an error will occur when helper() is
716 called.
717
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000718- The compiler will report a SyntaxError if "from ... import *" occurs
719 in a function or class scope. The language reference has documented
720 that this case is illegal, but the compiler never checked for it.
721 The recent introduction of nested scope makes the meaning of this
722 form of name binding ambiguous. In a future release, the compiler
723 may allow this form when there is no possibility of ambiguity.
724
Tim Peters40ead762001-01-27 05:35:26 +0000725- repr(string) is easier to read, now using hex escapes instead of octal,
726 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
727
728 >>> "\texample \r\n" + chr(0) + chr(255)
729 '\texample \r\n\x00\xff' # in 2.1
730 '\011example \015\012\000\377' # in 2.0
731
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000732- Functions are now compared and hashed by identity, not by value, since
733 the func_code attribute is writable.
734
Fred Drakefb9d7122001-02-01 20:00:40 +0000735- Weak references (PEP 205) have been added. This involves a few
736 changes in the core, an extension module (_weakref), and a Python
737 module (weakref). The weakref module is the public interface. It
738 includes support for "explicit" weak references, proxy objects, and
739 mappings with weakly held values.
740
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000741- A 'continue' statement can now appear in a try block within the body
742 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000743 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000744
Tim Petersd7b5e882001-01-25 03:36:26 +0000745Standard library
746
Barry Warsaw30dbd142001-01-31 22:14:01 +0000747- mailbox.py now has a new class, PortableUnixMailbox which is
748 identical to UnixMailbox but uses a more portable scheme for
749 determining From_ separators. Also, the constructors for all the
750 classes in this module have a new optional `factory' argument, which
751 is a callable used when new message classes must be instantiated by
752 the next() method.
753
Tim Petersd7b5e882001-01-25 03:36:26 +0000754- random.py is now self-contained, and offers all the functionality of
755 the now-deprecated whrandom.py. See the docs for details. random.py
756 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000757 and restoring the internal state of the generator; and jumpahead(n),
758 for quickly forcing the internal state to be the same as if n calls to
759 random() had been made. The latter is particularly useful for multi-
760 threaded programs, creating one instance of the random.Random() class for
761 each thread, then using .jumpahead() to force each instance to use a
762 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000763
Tim Peters0de88fc2001-02-01 04:59:18 +0000764- random.py's seed() function is new. For bit-for-bit compatibility with
765 prior releases, use the whseed function instead. The new seed function
766 addresses two problems: (1) The old function couldn't produce more than
767 about 2**24 distinct internal states; the new one about 2**45 (the best
768 that can be done in the Wichmann-Hill generator). (2) The old function
769 sometimes produced identical internal states when passed distinct
770 integers, and there was no simple way to predict when that would happen;
771 the new one guarantees to produce distinct internal states for all
772 arguments in [0, 27814431486576L).
773
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000774- The socket module now supports raw packets on Linux. The socket
775 family is AF_PACKET.
776
Tim Peters9ea17ac2001-02-02 05:57:15 +0000777- test_capi.py is a start at running tests of the Python C API. The tests
778 are implemented by the new Modules/_testmodule.c.
779
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000780- A new extension module, _symtable, provides provisional access to the
781 internal symbol table used by the Python compiler. A higher-level
782 interface will be added on top of _symtable in a future release.
783
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000784- Removed the obsolete soundex module.
785
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000786- xml.dom.minidom now uses the standard DOM exceptions. Node supports
787 the isSameNode method; NamedNodeMap the get method.
788
789- xml.sax.expatreader supports the lexical handler property; it
790 generates comment, startCDATA, and endCDATA events.
791
Tim Petersee826f82001-01-31 19:39:44 +0000792Windows changes
793
794- Build procedure: the zlib project is built in a different way that
795 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000796 the zlib binary used. See PCbuild\readme.txt for details. Your old
797 zlib-related directories can be deleted; you'll need to download fresh
798 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000799
Tim Peters9ea17ac2001-02-02 05:57:15 +0000800- Build: New subproject _test for the benefit of test_capi.py (see above).
801
Tim Petersb16c56f2001-02-02 21:24:51 +0000802- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
803 interface to some Python compiler internals).
804
805- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000806 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000807
Tim Petersa3a3a032000-11-30 05:22:44 +0000808What's New in Python 2.1 alpha 1?
809=================================
810
811Core language, builtins, and interpreter
812
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000813- There is a new Unicode companion to the PyObject_Str() API
814 called PyObject_Unicode(). It behaves in the same way as the
815 former, but assures that the returned value is an Unicode object
816 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000817
Guido van Rossumf98eda02001-01-17 15:54:45 +0000818- The comparison operators support "rich comparison overloading" (PEP
819 207). C extension types can provide a rich comparison function in
820 the new tp_richcompare slot in the type object. The cmp() function
821 and the C function PyObject_Compare() first try the new rich
822 comparison operators before trying the old 3-way comparison. There
823 is also a new C API PyObject_RichCompare() (which also falls back on
824 the old 3-way comparison, but does not constrain the outcome of the
825 rich comparison to a Boolean result).
826
827 The rich comparison function takes two objects (at least one of
828 which is guaranteed to have the type that provided the function) and
829 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
830 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
831 object, which may be NotImplemented (in which case the tp_compare
832 slot function is used as a fallback, if defined).
833
834 Classes can overload individual comparison operators by defining one
835 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000836 __ge__. There are no explicit "reflected argument" versions of
837 these; instead, __lt__ and __gt__ are each other's reflection,
838 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
839 reflection (similar at the C level). No other implications are
840 made; in particular, Python does not assume that == is the Boolean
841 inverse of !=, or that < is the Boolean inverse of >=. This makes
842 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000843
844 Classes or types that want to implement (in)equality tests but not
845 the ordering operators (i.e. unordered types) should implement ==
846 and !=, and raise an error for the ordering operators.
847
Guido van Rossuma88479f2001-01-18 14:28:08 +0000848 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000849 Boolean; e.g. a matrix type might want to return a matrix of bits
850 for A < B, giving elementwise comparisons. Such types should ensure
851 that any interpretation of their value in a Boolean context raises
852 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
853 at the C level) to always raise an exception.
854
Guido van Rossuma88479f2001-01-18 14:28:08 +0000855- Complex numbers use rich comparisons to define == and != but raise
856 an exception for <, <=, > and >=. Unfortunately, this also means
857 that cmp() of two complex numbers raises an exception when the two
858 numbers differ. Since it is not mathematically meaningful to compare
859 complex numbers except for equality, I hope that this doesn't break
860 too much code.
861
Tim Peters3389f192001-02-18 08:48:49 +0000862- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000863 not defined by the language, other than that it's arbitrary but
864 consistent (see the Reference Manual). An implementation detail changed
865 in 2.1a1 such that None now compares less than any other object. Code
866 relying on this new behavior (like code that relied on the previous
867 behavior) does so at its own risk.
868
Barry Warsaw573b5412001-01-15 20:43:18 +0000869- Functions and methods now support getting and setting arbitrarily
870 named attributes (PEP 232). Functions have a new __dict__
871 (a.k.a. func_dict) which hold the function attributes. Methods get
872 and set attributes on their underlying im_func. It is a TypeError
873 to set an attribute on a bound method.
874
Guido van Rossum051e3352001-01-15 19:11:10 +0000875- The xrange() object implementation has been improved so that
876 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
877 limitation that in this case len(xrange(sys.maxint)) can't be
878 calculated, but the common idiom "for i in xrange(sys.maxint)" will
879 work fine as long as the index i doesn't actually reach 2**31.
880 (Python uses regular ints for sequence and string indices; fixing
881 that is much more work.)
882
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000883- Two changes to from...import:
884
Guido van Rossumba381232001-02-03 15:06:40 +0000885 1) "from M import X" now works even if (after loading module M)
886 sys.modules['M'] is not a real module; it's basically a getattr()
887 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000888
889 2) "from M import *" now looks for M.__all__ to decide which names to
890 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
891 filters out names starting with '_' as before. Whether or not
892 __all__ exists, there's no restriction on the type of M.
893
Guido van Rossumf61f1662001-01-10 20:13:55 +0000894- File objects have a new method, xreadlines(). This is the fastest
895 way to iterate over all lines in a file:
896
897 for line in file.xreadlines():
898 ...do something to line...
899
900 See the xreadlines module (mentioned below) for how to do this for
901 other file-like objects.
902
903- Even if you don't use file.xreadlines(), you may expect a speedup on
904 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000905 quite a bit in platform-specific ways: on systems (like Linux) that
906 support flockfile(), getc_unlocked(), and funlockfile(), those are
907 used by default. On systems (like Windows) without getc_unlocked(),
908 a complicated (but still thread-safe) method using fgets() is used by
909 default.
910
Tim Petersd52269b2001-01-25 06:23:18 +0000911 You can force use of the fgets() method by #define'ing
912 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000913 getc_unlocked()).
914
Tim Petersd52269b2001-01-25 06:23:18 +0000915 You can force fgets() not to be used by #define'ing
916 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000917 test_bufio.py fails -- and let us know if it does!).
918
919- In addition, the fileinput module, while still slower than the other
920 methods on most platforms, has been sped up too, by using
921 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000922
923- Support for run-time warnings has been added, including a new
924 command line option (-W) to specify the disposition of warnings.
925 See the description of the warnings module below.
926
927- Extensive changes have been made to the coercion code. This mostly
928 affects extension modules (which can now implement mixed-type
929 numerical operators without having to use coercion), but
930 occasionally, in boundary cases the coercion semantics have changed
931 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000932 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000933 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000934 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000935
Guido van Rossumf98eda02001-01-17 15:54:45 +0000936- In connection with the coercion changes, a new built-in singleton
937 object, NotImplemented is defined. This can be returned for
938 operations that wish to indicate they are not implemented for a
939 particular combination of arguments. From C, this is
940 Py_NotImplemented.
941
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000942- The interpreter accepts now bytecode files on the command line even
943 if they do not have a .pyc or .pyo extension. On Linux, after executing
944
Martin v. Löwise214baa2001-02-04 22:37:56 +0000945import imp,sys,string
946magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
947reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
948open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000949
950 any byte code file can be used as an executable (i.e. as an argument
951 to execve(2)).
952
Tim Peters9940b802000-12-01 07:59:35 +0000953- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000954 character. In 1.6 and earlier, they never produced a sign,
955 and raised an error if the value of the long was too large
956 to fit in a Python int. In 2.0, they produced a sign if and
957 only if too large to fit in an int. This was inconsistent
958 across platforms (because the size of an int varies across
959 platforms), and inconsistent with hex() and oct(). Example:
960
961 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000962 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000963 'ffffffbe' # in 2.0 and before, on 32-bit machines
964 >>> hex(-0x42L)
965 '-0x42L' # in all versions of Python
966
Tim Peters9940b802000-12-01 07:59:35 +0000967 The behavior of %d formats for negative Python longs remains
968 the same as in 2.0 (although in 1.6 and before, they raised
969 an error if the long didn't fit in a Python int).
970
971 %u formats don't make sense for Python longs, but are allowed
972 and treated the same as %d in 2.1. In 2.0, a negative long
973 formatted via %u produced a sign if and only if too large to
974 fit in an int. In 1.6 and earlier, a negative long formatted
975 via %u raised an error if it was too big to fit in an int.
976
Guido van Rossum3661d392000-12-12 22:10:31 +0000977- Dictionary objects have an odd new method, popitem(). This removes
978 an arbitrary item from the dictionary and returns it (in the form of
979 a (key, value) pair). This can be useful for algorithms that use a
980 dictionary as a bag of "to do" items and repeatedly need to pick one
981 item. Such algorithms normally end up running in quadratic time;
982 using popitem() they can usually be made to run in linear time.
983
Tim Peters36cdad12000-12-29 02:06:45 +0000984Standard library
985
Thomas Woutersfe385252001-01-19 23:16:56 +0000986- In the time module, the time argument to the functions strftime,
987 localtime, gmtime, asctime and ctime is now optional, defaulting to
988 the current time (in the local timezone).
989
Guido van Rossumda91f222001-01-15 16:36:08 +0000990- The ftplib module now defaults to passive mode, which is deemed a
991 more useful default given that clients are often inside firewalls
992 these days. Note that this could break if ftplib is used to connect
993 to a *server* that is inside a firewall, from outside; this is
994 expected to be a very rare situation. To fix that, you can call
995 ftp.set_pasv(0).
996
Martin v. Löwis10a27872001-01-13 09:54:41 +0000997- The module site now treats .pth files not only for path configuration,
998 but also supports extensions to the initialization code: Lines starting
999 with import are executed.
1000
Guido van Rossumf61f1662001-01-10 20:13:55 +00001001- There's a new module, warnings, which implements a mechanism for
1002 issuing and filtering warnings. There are some new built-in
1003 exceptions that serve as warning categories, and a new command line
1004 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1005 turns warnings into errors). warnings.warn(message[, category])
1006 issues a warning message; this can also be called from C as
1007 PyErr_Warn(category, message).
1008
1009- A new module xreadlines was added. This exports a single factory
1010 function, xreadlines(). The intention is that this code is the
1011 absolutely fastest way to iterate over all lines in an open
1012 file(-like) object:
1013
1014 import xreadlines
1015 for line in xreadlines.xreadlines(file):
1016 ...do something to line...
1017
1018 This is equivalent to the previous the speed record holder using
1019 file.readlines(sizehint). Note that if file is a real file object
1020 (as opposed to a file-like object), this is equivalent:
1021
1022 for line in file.xreadlines():
1023 ...do something to line...
1024
Tim Peters36cdad12000-12-29 02:06:45 +00001025- The bisect module has new functions bisect_left, insort_left,
1026 bisect_right and insort_right. The old names bisect and insort
1027 are now aliases for bisect_right and insort_right. XXX_right
1028 and XXX_left methods differ in what happens when the new element
1029 compares equal to one or more elements already in the list: the
1030 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001031 right. Code that doesn't care where equal elements end up should
1032 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001033
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001034- The new curses.panel module wraps the panel library that forms part
1035 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1036
Guido van Rossumf61f1662001-01-10 20:13:55 +00001037- The SocketServer module now sets the allow_reuse_address flag by
1038 default in the TCPServer class.
1039
1040- A new function, sys._getframe(), returns the stack frame pointer of
1041 the caller. This is intended only as a building block for
1042 higher-level mechanisms such as string interpolation.
1043
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001044- The pyexpat module supports a number of new handlers, which are
1045 available only in expat 1.2. If invocation of a callback fails, it
1046 will report an additional frame in the traceback. Parser objects
1047 participate now in garbage collection. If expat reports an unknown
1048 encoding, pyexpat will try to use a Python codec; that works only
1049 for single-byte charsets. The parser type objects is exposed as
1050 XMLParserObject.
1051
1052- xml.dom now offers standard definitions for symbolic node type and
1053 exception code constants, and a hierarchy of DOM exceptions. minidom
1054 was adjusted to use them.
1055
1056- The conformance of xml.dom.minidom to the DOM specification was
1057 improved. It detects a number of additional error cases; the
1058 previous/next relationship works even when the tree is modified;
1059 Node supports the normalize() method; NamedNodeMap, DocumentType and
1060 DOMImplementation classes were added; Element supports the
1061 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1062 method.
1063
Guido van Rossumf61f1662001-01-10 20:13:55 +00001064Build issues
1065
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001066- For Unix (and Unix-compatible) builds, configuration and building of
1067 extension modules is now greatly automated. Rather than having to
1068 edit the Modules/Setup file to indicate which modules should be
1069 built and where their include files and libraries are, a
1070 distutils-based setup.py script now takes care of building most
1071 extension modules. All extension modules built this way are built
1072 as shared libraries. Only a few modules that must be linked
1073 statically are still listed in the Setup file; you won't need to
1074 edit their configuration.
1075
1076- Python should now build out of the box on Cygwin. If it doesn't,
1077 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001078
1079- Python now always uses its own (renamed) implementation of getopt()
1080 -- there's too much variation among C library getopt()
1081 implementations.
1082
1083- C++ compilers are better supported; the CXX macro is always set to a
1084 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001085
Tim Petersd92dfe02000-12-12 01:18:41 +00001086Windows changes
1087
1088- select module: By default under Windows, a select() call
1089 can specify no more than 64 sockets. Python now boosts
1090 this Microsoft default to 512. If you need even more than
1091 that, see the MS docs (you'll need to #define FD_SETSIZE
1092 and recompile Python from source).
1093
Guido van Rossumf61f1662001-01-10 20:13:55 +00001094- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1095 subdirectory is no more!
1096
Tim Petersa3a3a032000-11-30 05:22:44 +00001097
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001098What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001099=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001100
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001101Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001102changes are in the file HISTORY. If you are making the jump directly
1103from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1104HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001105
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001106Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1107the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1108http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001109
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001110--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001111
1112======================================================================
1113
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001114What's new in 2.0 (since release candidate 1)?
1115==============================================
1116
1117Standard library
1118
1119- The copy_reg module was modified to clarify its intended use: to
1120 register pickle support for extension types, not for classes.
1121 pickle() will raise a TypeError if it is passed a class.
1122
1123- Fixed a bug in gettext's "normalize and expand" code that prevented
1124 it from finding an existing .mo file.
1125
1126- Restored support for HTTP/0.9 servers in httplib.
1127
Tim Peters989b7b92000-10-16 20:24:53 +00001128- The math module was changed to stop raising OverflowError in case of
1129 underflow, and return 0 instead in underflow cases. Whether Python
1130 used to raise OverflowError in case of underflow was platform-
1131 dependent (it did when the platform math library set errno to ERANGE
1132 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001133
1134- Fixed a bug in StringIO that occurred when the file position was not
1135 at the end of the file and write() was called with enough data to
1136 extend past the end of the file.
1137
1138- Fixed a bug that caused Tkinter error messages to get lost on
1139 Windows. The bug was fixed by replacing direct use of
1140 interp->result with Tcl_GetStringResult(interp).
1141
1142- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1143 redirect response.
1144
1145- Several changes were made to distutils: Some debugging code was
1146 removed from util. Fixed the installer used when an external zip
1147 program (like WinZip) is not found; the source code for this
1148 installer is in Misc/distutils. check_lib() was modified to behave
1149 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1150 test for whether installed modules are on sys.path was changed to
1151 use both normcase() and normpath().
1152
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001153- Several minor bugs were fixed in the xml package (the minidom,
1154 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001155
1156- The regression test driver (regrtest.py) behavior when invoked with
1157 -l changed: It now reports a count of objects that are recognized as
1158 garbage but not freed by the garbage collector.
1159
Tim Peters989b7b92000-10-16 20:24:53 +00001160- The regression test for the math module was changed to test
1161 exceptional behavior when the test is run in verbose mode. Python
1162 cannot yet guarantee consistent exception behavior across platforms,
1163 so the exception part of test_math is run only in verbose mode, and
1164 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001165
1166Internals
1167
1168- PyOS_CheckStack() has been disabled on Win64, where it caused
1169 test_sre to fail.
1170
1171Build issues
1172
1173- Changed compiler flags, so that gcc is always invoked with -Wall and
1174 -Wstrict-prototypes. Users compiling Python with GCC should see
1175 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001176 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001177 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001178
Tim Petersa3a3a032000-11-30 05:22:44 +00001179- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001180
1181Tools and other miscellany
1182
1183- The compiler in Tools/compiler was updated to support the new
1184 language features introduced in 2.0: extended print statement, list
1185 comprehensions, and augmented assignments. The new compiler should
1186 also be backwards compatible with Python 1.5.2; the compiler will
1187 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001188 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001189
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001190What's new in 2.0 release candidate 1 (since beta 2)?
1191=====================================================
1192
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001193What is release candidate 1?
1194
1195We believe that release candidate 1 will fix all known bugs that we
1196intend to fix for the 2.0 final release. This release should be a bit
1197more stable than the previous betas. We would like to see even more
1198widespread testing before the final release, so we are producing this
1199release candidate. The final release will be exactly the same unless
1200any show-stopping (or brown bag) bugs are found by testers of the
1201release candidate.
1202
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001203All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001204to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001205
1206Core language, builtins, and interpreter
1207
1208- A bug that caused crashes when __coerce__ was used with augmented
1209 assignment, e.g. +=, was fixed.
1210
1211- Raise ZeroDivisionError when raising zero to a negative number,
1212 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1213 power operator and the result of math.pow(0.0, -2.0) will vary by
1214 platform. On Linux, it raises a ValueError.
1215
1216- A bug in Unicode string interpolation was fixed that occasionally
1217 caused errors with formats including "%%". For example, the
1218 following expression "%% %s" % u"abc" no longer raises a TypeError.
1219
1220- Compilation of deeply nested expressions raises MemoryError instead
1221 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1222
1223- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1224 rendering them useless. They are now written in binary mode again.
1225
1226Standard library
1227
1228- Keyword arguments are now accepted for most pattern and match object
1229 methods in SRE, the standard regular expression engine.
1230
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001231- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001232 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001233
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001234- Several bugs in the Unicode handling and error handling in _tkinter
1235 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001236
1237- Fix memory management errors in Merge() and Tkapp_Call() routines.
1238
1239- Several changes were made to cStringIO to make it compatible with
1240 the file-like object interface and with StringIO. If operations are
1241 performed on a closed object, an exception is raised. The truncate
1242 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001243 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001244
1245- There were many changes made to the linuxaudiodev module and its
1246 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001247 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001248
1249 Note that this module is named poorly, because it should work
1250 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001251 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001252
1253 The module now raises exceptions when errors occur instead of
1254 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1255 audio) and defines a getptr() method that calls the
1256 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1257
1258- The library_version attribute, introduced in an earlier beta, was
1259 removed because it can not be supported with early versions of the C
1260 readline library, which provides no way to determine the version at
1261 compile-time.
1262
1263- The binascii module is now enabled on Win64.
1264
Tim Peters46446d62000-10-09 21:19:31 +00001265- tokenize.py no longer suffers "recursion depth" errors when parsing
1266 programs with very long string literals.
1267
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001268Internals
1269
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001270- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001271 which is called when the interpreter starts up to determine where
1272 the standard library is installed. These vulnerabilities affect all
1273 previous versions of Python and can be exploited by setting very
1274 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1275 setuid Python script, although use of the wrapper in
1276 Misc/setuid-prog.c will eliminate the vulnerability.
1277
1278- Fixed garbage collection bugs in instance creation that were
1279 triggered when errors occurred during initialization. The solution,
1280 applied in cPickle and in PyInstance_New(), is to call
1281 PyObject_GC_Init() after the initialization of the object's
1282 container attributes is complete.
1283
1284- pyexpat adds definitions of PyModule_AddStringConstant and
1285 PyModule_AddObject if the Python version is less than 2.0, which
1286 provides compatibility with PyXML on Python 1.5.2.
1287
1288- If the platform has a bogus definition for LONG_BIT (the number of
1289 bits in a long), an error will be reported at compile time.
1290
1291- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1292 collection crashes and possibly other, unreported crashes.
1293
1294- Fixed a memory leak in _PyUnicode_Fini().
1295
1296Build issues
1297
1298- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001299 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001300 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001301
1302- The mmap.PAGESIZE constant is now initialized using sysconf when
1303 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1304
1305- The md5 file should now compile on all platforms.
1306
1307- The select module now compiles on platforms that do not define
1308 POLLRDNORM and related constants.
1309
1310- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001311 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001312
Jeremy Hylton10921202000-10-09 18:34:12 +00001313- BeOS: A number of changes were made to the build and installation
1314 process. ar-fake now operates on a directory of object files.
1315 dl_export.h is gone, and its macros now appear on the mwcc command
1316 line during build on PPC BeOS.
1317
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001318- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001319 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001320
1321- Cygwin: Support for shared libraries, Tkinter, and sockets.
1322
1323- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1324
1325Tools and other miscellany
1326
1327- Removed debugging prints from main used with freeze.
1328
Tim Peters46446d62000-10-09 21:19:31 +00001329- IDLE auto-indent no longer crashes when it encounters Unicode
1330 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001331
1332What's new in 2.0 beta 2 (since beta 1)?
1333========================================
1334
1335Core language, builtins, and interpreter
1336
Tim Peters482c0212000-09-26 06:33:09 +00001337- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001338 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001339
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001340- Add -h and -V command line options to print the usage message and
1341 Python version number and exit immediately.
1342
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001343- eval() and exec accept Unicode objects as code parameters.
1344
1345- getattr() and setattr() now also accept Unicode objects for the
1346 attribute name, which are converted to strings using the default
1347 encoding before lookup.
1348
1349- Multiplication on string and Unicode now does proper bounds
1350 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1351 string is too long."
1352
1353- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001354 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001355
Jeremy Hylton1b618592000-09-26 05:32:36 +00001356
1357Standard library and extensions
1358
Guido van Rossum5b08f132001-04-16 02:05:23 +00001359- socket module: the OpenSSL code now adds support for RAND_status()
1360 and EGD (Entropy Gathering Device).
1361
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001362- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001363 argument checking; it still takes no arguments.
1364
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001365- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001366
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001367- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001368
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001369- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001370
1371- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001372 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001373
1374- copy: Copy Unicode objects atomically.
1375
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001376- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001377
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001378- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001379
Fred Drake67233bc2000-09-26 16:40:27 +00001380- dbm: Add get() and setdefault() methods to dbm object. Add constant
1381 `library' to module that names the library used. Added doc strings
1382 and method names to error messages. Uses configure to determine
1383 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1384 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001385
1386- distutils: Update to version 0.9.3.
1387
1388- dl: Add several dl.RTLD_ constants.
1389
1390- fpectl: Now supported on FreeBSD.
1391
1392- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1393 found by the collector will be saved in gc.garbage. This is useful
1394 for debugging a program that creates reference cycles.
1395
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001396- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001397 of HTTP class. Do not close socket on zero-length response. Do not
1398 crash when server sends invalid content-length header.
1399
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001400- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001401
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001402- marshal: When reading a short, sign-extend on platforms where shorts
1403 are bigger than 16 bits. When reading a long, repair the unportable
1404 sign extension that was being done for 64-bit machines. (It assumed
1405 that signed right shift sign-extends.)
1406
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001407- operator: Add contains(), invert(), __invert__() as aliases for
1408 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001409
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001410- os: Add support for popen2() and popen3() on all platforms where
1411 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001412
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001413- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001414 clicking on a file in Explorer (or passing the file name to the
1415 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001416
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001417- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001418 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001419
1420- pickle: Now raises ValueError when an invalid pickle that contains
1421 a non-string repr where a string repr was expected. This behavior
1422 matches cPickle.
1423
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001424- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001425
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001426- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001427
1428- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001429 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001430 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001431
1432- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001433 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001434
1435- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001436 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001437 few cycles during startup since the first call to
1438 setdefaultencoding() will initialize the codec registry and the
1439 encodings package.
1440
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001441- socket: Support for size hint in readlines() method of object returned
1442 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001443
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001444- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001445 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001446 is followed by whitespace.
1447
Tim Petersa3a3a032000-11-30 05:22:44 +00001448- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001449
1450- struct: Check ranges for bytes and shorts.
1451
1452- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001453 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001454
1455- Tkinter: Image objects are now guaranteed to have unique ids. Set
1456 event.delta to zero if Tk version doesn't support mousewheel.
1457 Removed some debugging prints.
1458
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001459- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001460
Fred Drake67233bc2000-09-26 16:40:27 +00001461- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001462 which works around a bug in Norton AntiVirus 2000 that leads directly
1463 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001464
1465- xml: New version detection code allows PyXML to override standard
1466 XML package if PyXML version is greater than 0.6.1.
1467
Fred Drake64bb3802000-09-26 16:21:35 +00001468- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1469 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1470 tree only for nodes which are sufficiently interesting to a specific
1471 application. Does not provide the HTML-specific extensions. Still
1472 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001473
Fred Drake64bb3802000-09-26 16:21:35 +00001474- xml.sax: SAX 2 support for Python, including all the handler
1475 interfaces needed to process XML 1.0 compliant XML. Some
1476 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001477
Fred Drake64bb3802000-09-26 16:21:35 +00001478- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1479 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001480
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001481
Jeremy Hylton1b618592000-09-26 05:32:36 +00001482C API
1483
1484- Add three new convenience functions for module initialization --
1485 PyModule_AddObject(), PyModule_AddIntConstant(), and
1486 PyModule_AddStringConstant().
1487
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001488- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001489 removed and add #error to Python.h if NULL isn't defined after
1490 #include of stdio.h.
1491
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001492- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001493 backwards compatibility (at the source level) with old extensions.
1494
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001495- A wrapper API was added for signal() and sigaction(). Instead of
1496 either function, always use PyOS_getsig() to get a signal handler
1497 and PyOS_setsig() to set one. A new convenience typedef
1498 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001499
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001500- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001501 internal data buffer and size of a string object -- or the default
1502 encoded version of a Unicode object.
1503
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001504- PyString_Size() and PyString_AsString() accept Unicode objects.
1505
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001506- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001507 exists). INT_MAX and LONG_MAX will always be defined, even if
1508 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001509
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001510- PyFloat_FromString takes a second argument, pend, that was
1511 effectively useless. It is now officially useless but preserved for
1512 backwards compatibility. If the pend argument is not NULL, *pend is
1513 set to NULL.
1514
1515- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1516 for the attribute name. See note on getattr() above.
1517
1518- A few bug fixes to argument processing for Unicode.
1519 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1520 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1521 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001522 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001523
1524- Py_BuildValue accepts B format (for bgen-generated code).
1525
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001526
Jeremy Hylton1b618592000-09-26 05:32:36 +00001527Internals
1528
1529- On Unix, fix code for finding Python installation directory so that
1530 it works when argv[0] is a relative path.
1531
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001532- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001533 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001534 rather than by generating a copy of the object.
1535
Tim Peters482c0212000-09-26 06:33:09 +00001536- Several of the internal Unicode tables are much smaller now, and
1537 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001538
Jeremy Hylton97693b02000-09-26 17:42:51 +00001539- In the garbage collector: Fixed bug in collection of tuples. Fixed
1540 bug that caused some instances to be removed from the container set
1541 while they were still live. Fixed parsing in gc.set_debug() for
1542 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001543
1544- Fixed refcount problem in instance deallocation that only occurred
1545 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1546
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001547- On Windows, getpythonregpath is now protected against null data in
1548 registry key.
1549
1550- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001551 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001552
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001553
Jeremy Hylton1b618592000-09-26 05:32:36 +00001554Build and platform-specific issues
1555
1556- Better support of GNU Pth via --with-pth configure option.
1557
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001558- Python/C API now properly exposed to dynamically-loaded extension
1559 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001560
1561- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1562 Don't define MS_SYNC to be zero when it is undefined. Added missing
1563 prototypes in posixmodule.c.
1564
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001565- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001566 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001567
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001568- Fix largefile support on older NetBSD systems and OpenBSD by adding
1569 define for TELL64.
1570
1571
1572Tools and other miscellany
1573
1574- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1575
1576- freeze: The modulefinder now works with 2.0 opcodes.
1577
Tim Petersa3a3a032000-11-30 05:22:44 +00001578- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001579 Move hackery of sys.argv until after the Tk instance has been
1580 created, which allows the application-specific Tkinter
1581 initialization to be executed if present; also pass an explicit
1582 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001583
Jeremy Hylton1b618592000-09-26 05:32:36 +00001584
1585What's new in 2.0 beta 1?
1586=========================
1587
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001588Source Incompatibilities
1589------------------------
1590
1591None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1592such as single-argument append(), connect() and bind(), and changes to
1593str(long) and repr(float).
1594
1595
1596Binary Incompatibilities
1597------------------------
1598
1599- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1600with Python 2.0; these extensions will have to be rebuilt for Python
16012.0.
1602
1603- On Windows, attempting to import a third party extension built for
1604Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1605can do about this. Check your PYTHONPATH environment variable!
1606
1607- Python bytecode files (*.pyc and *.pyo) are not compatible between
1608releases.
1609
1610
1611Overview of Changes Since 1.6
1612-----------------------------
1613
1614There are many new modules (including brand new XML support through
1615the xml package, and i18n support through the gettext module); a list
1616of all new modules is included below. Lots of bugs have been fixed.
1617
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001618The process for making major new changes to the language has changed
1619since Python 1.6. Enhancements must now be documented by a Python
1620Enhancement Proposal (PEP) before they can be accepted.
1621
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001622There are several important syntax enhancements, described in more
1623detail below:
1624
1625 - Augmented assignment, e.g. x += 1
1626
1627 - List comprehensions, e.g. [x**2 for x in range(10)]
1628
1629 - Extended import statement, e.g. import Module as Name
1630
1631 - Extended print statement, e.g. print >> file, "Hello"
1632
1633Other important changes:
1634
1635 - Optional collection of cyclical garbage
1636
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001637Python Enhancement Proposal (PEP)
1638---------------------------------
1639
1640PEP stands for Python Enhancement Proposal. A PEP is a design
1641document providing information to the Python community, or describing
1642a new feature for Python. The PEP should provide a concise technical
1643specification of the feature and a rationale for the feature.
1644
1645We intend PEPs to be the primary mechanisms for proposing new
1646features, for collecting community input on an issue, and for
1647documenting the design decisions that have gone into Python. The PEP
1648author is responsible for building consensus within the community and
1649documenting dissenting opinions.
1650
1651The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001652
1653Augmented Assignment
1654--------------------
1655
1656This must have been the most-requested feature of the past years!
1657Eleven new assignment operators were added:
1658
Guido van Rossume905e952000-09-05 12:42:46 +00001659 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001660
1661For example,
1662
1663 A += B
1664
1665is similar to
1666
1667 A = A + B
1668
1669except that A is evaluated only once (relevant when A is something
1670like dict[index].attr).
1671
1672However, if A is a mutable object, A may be modified in place. Thus,
1673if A is a number or a string, A += B has the same effect as A = A+B
1674(except A is only evaluated once); but if a is a list, A += B has the
1675same effect as A.extend(B)!
1676
1677Classes and built-in object types can override the new operators in
1678order to implement the in-place behavior; the not-in-place behavior is
1679used automatically as a fallback when an object doesn't implement the
1680in-place behavior. For classes, the method name is derived from the
1681method name for the corresponding not-in-place operator by inserting
1682an 'i' in front of the name, e.g. __iadd__ implements in-place
1683__add__.
1684
1685Augmented assignment was implemented by Thomas Wouters.
1686
1687
1688List Comprehensions
1689-------------------
1690
1691This is a flexible new notation for lists whose elements are computed
1692from another list (or lists). The simplest form is:
1693
1694 [<expression> for <variable> in <sequence>]
1695
Guido van Rossum56db0952000-09-06 23:34:25 +00001696For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001697This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001698
1699You can also add a condition:
1700
1701 [<expression> for <variable> in <sequence> if <condition>]
1702
1703For example, [w for w in words if w == w.lower()] would yield the list
1704of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001705than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001706
1707You can also have nested for loops and more than one 'if' clause. For
1708example, here's a function that flattens a sequence of sequences::
1709
1710 def flatten(seq):
1711 return [x for subseq in seq for x in subseq]
1712
1713 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1714
1715This prints
1716
1717 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1718
1719List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001720Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001721
1722
1723Extended Import Statement
1724-------------------------
1725
1726Many people have asked for a way to import a module under a different
1727name. This can be accomplished like this:
1728
1729 import foo
1730 bar = foo
1731 del foo
1732
1733but this common idiom gets old quickly. A simple extension of the
1734import statement now allows this to be written as follows:
1735
1736 import foo as bar
1737
1738There's also a variant for 'from ... import':
1739
1740 from foo import bar as spam
1741
1742This also works with packages; e.g. you can write this:
1743
1744 import test.regrtest as regrtest
1745
1746Note that 'as' is not a new keyword -- it is recognized only in this
1747context (this is only possible because the syntax for the import
1748statement doesn't involve expressions).
1749
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001750Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001751
1752
1753Extended Print Statement
1754------------------------
1755
1756Easily the most controversial new feature, this extension to the print
1757statement adds an option to make the output go to a different file
1758than the default sys.stdout.
1759
1760For example, to write an error message to sys.stderr, you can now
1761write:
1762
1763 print >> sys.stderr, "Error: bad dog!"
1764
1765As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001766evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001767
1768 print >> None, "Hello world"
1769
1770is equivalent to
1771
1772 print "Hello world"
1773
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001774Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001775
1776
1777Optional Collection of Cyclical Garbage
1778---------------------------------------
1779
1780Python is now equipped with a garbage collector that can hunt down
1781cyclical references between Python objects. It's no replacement for
1782reference counting; in fact, it depends on the reference counts being
1783correct, and decides that a set of objects belong to a cycle if all
1784their reference counts can be accounted for from their references to
1785each other. This devious scheme was first proposed by Eric Tiedemann,
1786and brought to implementation by Neil Schemenauer.
1787
1788There's a module "gc" that lets you control some parameters of the
1789garbage collection. There's also an option to the configure script
1790that lets you enable or disable the garbage collection. In 2.0b1,
1791it's on by default, so that we (hopefully) can collect decent user
1792experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001793performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001794off by default in the final 2.0 release.
1795
1796
1797Smaller Changes
1798---------------
1799
1800A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1801map(None, seq1, seq2, ...) when the sequences have the same length;
1802i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1803the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001804zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001805
1806sys.version_info is a tuple (major, minor, micro, level, serial).
1807
1808Dictionaries have an odd new method, setdefault(key, default).
1809dict.setdefault(key, default) returns dict[key] if it exists; if not,
1810it sets dict[key] to default and returns that value. Thus:
1811
1812 dict.setdefault(key, []).append(item)
1813
1814does the same work as this common idiom:
1815
1816 if not dict.has_key(key):
1817 dict[key] = []
1818 dict[key].append(item)
1819
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001820There are two new variants of SyntaxError that are raised for
1821indentation-related errors: IndentationError and TabError.
1822
1823Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1824escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001825
1826The limits on the size of expressions and file in Python source code
1827have been raised from 2**16 to 2**32. Previous versions of Python
1828were limited because the maximum argument size the Python VM accepted
1829was 2**16. This limited the size of object constructor expressions,
1830e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1831limit was raised thanks to a patch by Charles Waldman that effectively
1832fixes the problem. It is now much more likely that you will be
1833limited by available memory than by an arbitrary limit in Python.
1834
1835The interpreter's maximum recursion depth can be modified by Python
1836programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1837limit is the maximum number of recursive calls that can be made by
1838Python code. The limit exists to prevent infinite recursion from
1839overflowing the C stack and causing a core dump. The default value is
18401000. The maximum safe value for a particular platform can be found
1841by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001842
1843New Modules and Packages
1844------------------------
1845
1846atexit - for registering functions to be called when Python exits.
1847
1848imputil - Greg Stein's alternative API for writing custom import
1849hooks.
1850
1851pyexpat - an interface to the Expat XML parser, contributed by Paul
1852Prescod.
1853
1854xml - a new package with XML support code organized (so far) in three
1855subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1856would fill a volume. There's a special feature whereby a
1857user-installed package named _xmlplus overrides the standard
1858xmlpackage; this is intended to give the XML SIG a hook to distribute
1859backwards-compatible updates to the standard xml package.
1860
1861webbrowser - a platform-independent API to launch a web browser.
1862
1863
Guido van Rossume905e952000-09-05 12:42:46 +00001864Changed Modules
1865---------------
1866
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001867array -- new methods for array objects: count, extend, index, pop, and
1868remove
1869
1870binascii -- new functions b2a_hex and a2b_hex that convert between
1871binary data and its hex representation
1872
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001873calendar -- Many new functions that support features including control
1874over which day of the week is the first day, returning strings instead
1875of printing them. Also new symbolic constants for days of week,
1876e.g. MONDAY, ..., SUNDAY.
1877
1878cgi -- FieldStorage objects have a getvalue method that works like a
1879dictionary's get method and returns the value attribute of the object.
1880
1881ConfigParser -- The parser object has new methods has_option,
1882remove_section, remove_option, set, and write. They allow the module
1883to be used for writing config files as well as reading them.
1884
1885ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001886optionally support the RFC 959 REST command.
1887
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001888gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001889
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001890httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1891the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001892
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001893locale -- implement getdefaultlocale for Win32 and Macintosh
1894
1895marshal -- no longer dumps core when marshaling deeply nested or
1896recursive data structures
1897
1898os -- new functions isatty, seteuid, setegid, setreuid, setregid
1899
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001900os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1901support under Unix.
1902
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001903os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001904
1905os.path -- fix semantics of os.path.commonprefix
1906
1907smtplib -- support for sending very long messages
1908
1909socket -- new function getfqdn()
1910
1911readline -- new functions to read, write and truncate history files.
1912The readline section of the library reference manual contains an
1913example.
1914
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001915select -- add interface to poll system call
1916
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001917shutil -- new copyfileobj function
1918
1919SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1920HTTP server.
1921
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001922Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001923
1924urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001925e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001926
1927whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001928
1929
1930Obsolete Modules
1931----------------
1932
1933None. However note that 1.6 made a whole slew of modules obsolete:
1934stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1935poly, zmod, strop, util, whatsound.
1936
1937
1938Changed, New, Obsolete Tools
1939----------------------------
1940
Tim Peters8b092332000-09-05 20:15:25 +00001941None.
Guido van Rossume905e952000-09-05 12:42:46 +00001942
1943
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001944C-level Changes
1945---------------
1946
1947Several cleanup jobs were carried out throughout the source code.
1948
1949All C code was converted to ANSI C; we got rid of all uses of the
1950Py_PROTO() macro, which makes the header files a lot more readable.
1951
1952Most of the portability hacks were moved to a new header file,
1953pyport.h; several other new header files were added and some old
1954header files were removed, in an attempt to create a more rational set
1955of header files. (Few of these ever need to be included explicitly;
1956they are all included by Python.h.)
1957
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001958Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001959and Win64, especially for the new Intel Itanium processor. Mick also
1960added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001961
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001962The C APIs to return an object's size have been update to consistently
1963use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1964previous versions, the abstract interfaces used PyXXX_Length and the
1965concrete interfaces used PyXXX_Size. The old names,
1966e.g. PyObject_Length, are still available for backwards compatibility
1967at the API level, but are deprecated.
1968
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001969The PyOS_CheckStack function has been implemented on Windows by
1970Fredrik Lundh. It prevents Python from failing with a stack overflow
1971on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001972
1973The GC changes resulted in creation of two new slots on object,
1974tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001975the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001976
1977The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001978C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001979
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001980PyErr_Format has been updated to automatically calculate the size of
1981the buffer needed to hold the formatted result string. This change
1982prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001983
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001984New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001985
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001986PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1987that are the same as their non-Ex counterparts except they take an
1988extra flag argument that tells them to close the file when done.
1989
1990XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001991
Tim Peters8b092332000-09-05 20:15:25 +00001992
1993Windows Changes
1994---------------
1995
1996New popen2/popen3/peopen4 in os module (see Changed Modules above).
1997
1998os.popen is much more usable on Windows 95 and 98. See Microsoft
1999Knowledge Base article Q150956. The Win9x workaround described there
2000is implemented by the new w9xpopen.exe helper in the root of your
2001Python installation. Note that Python uses this internally; it is not
2002a standalone program.
2003
2004Administrator privileges are no longer required to install Python
2005on Windows NT or Windows 2000. If you have administrator privileges,
2006Python's registry info will be written under HKEY_LOCAL_MACHINE.
2007Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002008under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002009uses of Python, but will prevent some advanced uses from working
2010(for example, running a Python script as an NT service, or possibly
2011from CGI).
2012
2013[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2014installer; instead, it installs the needed Tcl/Tk files directly in the
2015Python directory. If you already have a Tcl/Tk installation, this
2016wastes some disk space (about 4 Megs) but avoids problems with
2017conflicting Tcl/Tk installations, and makes it much easier for Python
2018to ensure that Tcl/Tk can find all its files.
2019
2020[This was new in 1.6] The Windows installer now installs by default in
2021\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2022
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002023
2024Updates to the changes between 1.5.2 and 1.6
2025--------------------------------------------
2026
2027The 1.6 NEWS file can't be changed after the release is done, so here
2028is some late-breaking news:
2029
2030New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2031and changes to getlocale() and setlocale().
2032
2033The new module is now enabled per default.
2034
2035It is not true that the encodings codecs cannot be used for normal
2036strings: the string.encode() (which is also present on 8-bit strings
2037!) allows using them for 8-bit strings too, e.g. to convert files from
2038cp1252 (Windows) to latin-1 or vice-versa.
2039
2040Japanese codecs are available from Tamito KAJIYAMA:
2041http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2042
2043
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002044======================================================================