blob: 643564e9a09139aae099254fdc9355fd2a501029 [file] [log] [blame]
Tim Peters20f51a72001-07-21 02:31:40 +00001What's New in Python 2.2a2?
2===========================
3
4Tests
5
6- Several new tests in the standard test suite, with special thanks to
7 Nick Mathewson.
8
9Core
10
11Library
12
Fred Drakeb7cea632001-07-21 12:25:10 +000013- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
14 value using the minimal quoting required for the value; more
15 reliable than using xml.sax.saxutils.escape() for attribute values.
16
Tim Peters20f51a72001-07-21 02:31:40 +000017New platforms
18
19C API
20
21
Guido van Rossum55a78992001-07-17 17:22:32 +000022What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +000023===========================
24
25Core
Tim Petersa814db52001-05-14 07:05:58 +000026
Guido van Rossum55a78992001-07-17 17:22:32 +000027- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +000028 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +000029 more 'yield' statements. See PEP 255. Since this adds a new
30 keyword to the language, this feature must be enabled by including a
31 future statement: "from __future__ import generators" (see PEP 236).
32 Generators will become a standard feature in a future release
33 (probably 2.3). Without this future statement, 'yield' remains an
34 ordinary identifier, but a warning is issued each time it is used.
35 (These warnings currently don't conform to the warnings framework of
36 PEP 230; we intend to fix this in 2.2a2.)
37
Marc-André Lemburg12e74b32001-05-22 08:58:23 +000038- The UTF-16 codec was modified to be more RFC compliant. It will now
39 only remove BOM characters at the start of the string and then
40 only if running in native mode (UTF-16-LE and -BE won't remove a
41 leading BMO character).
42
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000043- Strings now have a new method .decode() to complement the already
44 existing .encode() method. These two methods provide direct access
45 to the corresponding decoders and encoders of the registered codecs.
46
47 To enhance the usability of the .encode() method, the special
48 casing of Unicode object return values was dropped (Unicode objects
49 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +000050
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000051 Both methods will now return whatever the codec in charge of the
52 requested encoding returns as object, e.g. Unicode codecs will
53 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
54 will return u"äöü"). This enables codec writer to create codecs
55 for various simple to use conversions.
56
57 New codecs were added to demonstrate these new features (the .encode()
58 and .decode() columns indicate the type of the returned objects):
59
60 Name | .encode() | .decode() | Description
61 ----------------------------------------------------------------------
62 uu | string | string | UU codec (e.g. for email)
63 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +000064 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000065 zlib | string | string | zlib compression
66 hex | string | string | 2-byte hex codec
67 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
68
Mark Hammond2a0af792001-05-14 03:09:36 +000069- Some operating systems now support the concept of a default Unicode
70 encoding for file system operations. Notably, Windows supports 'mbcs'
71 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +000072 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000073 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000074
75 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000076 functions that return filenames (such as os.listdir()) to return Python
77 string objects pre-encoded using the default file system encoding for
78 the platform. As this encoding is likely to be different from Python's
79 default encoding, converting this name to a Unicode object before passing
80 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000081 would attempt to use its default encoding (generally ASCII) rather than
82 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000083
Tim Petersa814db52001-05-14 07:05:58 +000084 In general, this change simply removes surprises when working with
85 Unicode and the file system, making these operations work as you expect,
86 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +000087 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +000088
Tim Peters61dff2b2001-05-08 15:43:37 +000089- Float (and complex) literals in source code were evaluated to full
90 precision only when running from a .py file; the same code loaded from a
91 .pyc (or .pyo) file could suffer numeric differences starting at about the
92 12th significant decimal digit. For example, on a machine with IEEE-754
93 floating arithmetic,
94
95 x = 9007199254740992.0
96 print long(x)
97
98 printed 9007199254740992 if run directly from .py, but 9007199254740000
99 if from a compiled (.pyc or .pyo) file. This was due to marshal using
100 str(float) instead of repr(float) when building code objects. marshal
101 now uses repr(float) instead, which should reproduce floats to full
102 machine precision (assuming the platform C float<->string I/O conversion
103 functions are of good quality).
104
105 This may cause floating-point results to change in some cases, and
106 usually for the better, but may also cause numerically unstable
107 algorithms to break.
108
Tim Peters2f228e72001-05-13 00:19:31 +0000109- The implementation of dicts suffers fewer collisions, which has speed
110 benefits. However, the order in which dict entries appear in dict.keys(),
111 dict.values() and dict.items() may differ from previous releases for a
112 given dict. Nothing is defined about this order, so no program should
113 rely on it. Nevertheless, it's easy to write test cases that rely on the
114 order by accident, typically because of printing the str() or repr() of a
115 dict to an "expected results" file. See Lib/test/test_support.py's new
116 sortdict(dict) function for a simple way to display a dict in sorted
117 order.
118
Tim Peters7a3bfc32001-06-12 01:22:22 +0000119- Many other small changes to dicts were made, resulting in faster
120 operation along the most common code paths.
121
Guido van Rossum10315822001-05-01 20:54:30 +0000122- Dictionary objects now support the "in" operator: "x in dict" means
123 the same as dict.has_key(x).
124
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000125- The update() method of dictionaries now accepts generic mapping
126 objects. Specifically the argument object must support the .keys()
127 and __getitem__() methods. This allows you to say, for example,
128 {}.update(UserDict())
129
Guido van Rossum10315822001-05-01 20:54:30 +0000130- Iterators were added; this is a generalized way of providing values
131 to a for loop. See PEP 234. There's a new built-in function iter()
132 to return an iterator. There's a new protocol to get the next value
133 from an iterator using the next() method (in Python) or the
134 tp_iternext slot (in C). There's a new protocol to get iterators
135 using the __iter__() method (in Python) or the tp_iter slot (in C).
136 Iterating (i.e. a for loop) over a dictionary generates its keys.
137 Iterating over a file generates its lines.
138
Tim Petersf553f892001-05-01 20:45:31 +0000139- The following functions were generalized to work nicely with iterator
140 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000141 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000142 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
143 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000144 join() method of strings
145 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000146 'x in y' and 'x not in y' (PySequence_Contains() in C API)
147 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000148 right-hand side of assignment statements with multiple targets, such as
149 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000150
Tim Petersd85e1022001-05-11 21:51:48 +0000151- Accessing module attributes is significantly faster (for example,
152 random.random or os.path or yourPythonModule.yourAttribute).
153
Tim Peterse63415e2001-05-08 04:38:29 +0000154- Comparing dictionary objects via == and != is faster, and now works even
155 if the keys and values don't support comparisons other than ==.
156
Tim Peters95bf9392001-05-10 08:32:44 +0000157- Comparing dictionaries in ways other than == and != is slower: there were
158 insecurities in the dict comparison implementation that could cause Python
159 to crash if the element comparison routines for the dict keys and/or
160 values mutated the dicts. Making the code bulletproof slowed it down.
161
Tim Peterseb28ef22001-06-02 05:27:19 +0000162- Collisions in dicts are resolved via a new approach, which can help
163 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000164 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000165 faster now. Thanks to Christian Tismer for pointing out the cause and
166 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000167
Tim Peters52e155e2001-06-16 05:42:57 +0000168- repr() is much faster for large containers (dict, list, tuple).
169
170
Tim Petersa814db52001-05-14 07:05:58 +0000171Library
172
Fred Drake960fdf92001-07-20 18:38:26 +0000173- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
174 were added to the string module. These a locale-indenpendent
175 constants, unlike letters, lowercase, and uppercase. These are now
176 use in appropriate locations in the standard library.
177
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000178- The flags used in dlopen calls can now be configured using
179 sys.setdlopenflags and queried using sys.getdlopenflags.
180
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000181- Fredrik Lundh's xmlrpclib is now a standard library module. This
182 provides full client-side XML-RPC support. In addition,
183 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
184 one asyncore-based). Thanks to Eric Raymond for the documentation.
185
Guido van Rossum643d3912001-07-05 14:46:25 +0000186- The xrange() object is simplified: it no longer supports slicing,
187 repetition, comparisons, efficient 'in' checking, the tolist()
188 method, or the start, stop and step attributes. See PEP 260.
189
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000190- A new function fnmatch.filter to filter lists of file names was added.
191
Barry Warsawffd674d2001-05-22 16:00:10 +0000192- calendar.py uses month and day names based on the current locale.
193
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000194- strop is now *really* obsolete (this was announced before with 1.6),
195 and issues DeprecationWarning when used (except for the four items
196 that are still imported into string.py).
197
Tim Petersa814db52001-05-14 07:05:58 +0000198- Cookie.py now sorts key+value pairs by key in output strings.
199
200- pprint.isrecursive(object) didn't correctly identify recursive objects.
201 Now it does.
202
Tim Peters95b3f782001-05-14 18:39:41 +0000203- pprint functions now much faster for large containers (tuple, list, dict).
204
Tim Peters7b9542a2001-06-10 23:40:19 +0000205- New 'q' and 'Q' format codes in the struct module, corresponding to C
206 types "long long" and "unsigned long long" (on Windows, __int64). In
207 native mode, these can be used only when the platform C compiler supports
208 these types (when HAVE_LONG_LONG is #define'd by the Python config
209 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000210 In standard mode, 'q' and 'Q' are supported on all platforms, and are
211 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000212
Guido van Rossum83213cc2001-06-12 16:48:52 +0000213- The site module installs a new built-in function 'help' that invokes
214 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
215 it displays a message reminding the user to use 'help()' or
216 'help(object)'.
217
Tim Petersa814db52001-05-14 07:05:58 +0000218Tests
219
220- New test_mutants.py runs dict comparisons where the key and value
221 comparison operators mutute the dicts randomly during comparison. This
222 rapidly causes Python to crash under earlier releases (not for the faint
223 of heart: it can also cause Win9x to freeze or reboot!).
224
225- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000226 pprint.isreadable() return sensible results. Also verifies that simple
227 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000228
Tim Peters58e0a8c2001-05-14 22:32:33 +0000229New platforms
230
231- Python should compile and run out of the box using the Borland C
232 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000233
Tim Peters4324aa32001-05-28 22:30:08 +0000234C API
235
236- Removed the unused last_is_sticky argument from the internal
237 _PyTuple_Resize(). If this affects you, you were cheating.
238
239
Guido van Rossum55a78992001-07-17 17:22:32 +0000240======================================================================
241
242
Guido van Rossumffe13be2001-04-16 18:46:45 +0000243What's New in Python 2.1 (final)?
244=================================
245
246We only changed a few things since the last release candidate, all in
247Python library code:
248
249- A bug in the locale module was fixed that affected locales which
250 define no grouping for numeric formatting.
251
252- A few bugs in the weakref module's implementations of weak
253 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
254 and the test suite was updated to check for these bugs.
255
256- An old bug in the os.path.walk() function (introduced in Python
257 2.0!) was fixed: a non-existent file would cause an exception
258 instead of being ignored.
259
260- Fixed a few bugs in the new symtable module found by Neil Norwitz's
261 PyChecker.
262
263
Guido van Rossum5b08f132001-04-16 02:05:23 +0000264What's New in Python 2.1c2?
265===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000266
Guido van Rossum5b08f132001-04-16 02:05:23 +0000267A flurry of small changes, and one showstopper fixed in the nick of
268time made it necessary to release another release candidate. The list
269here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000270
Guido van Rossum5b08f132001-04-16 02:05:23 +0000271Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000272
Guido van Rossum5b08f132001-04-16 02:05:23 +0000273- Tim discovered a nasty bug in the dictionary code, caused by
274 PyDict_Next() calling dict_resize(), and the GC code's use of
275 PyDict_Next() violating an assumption in dict_items(). This was
276 fixed with considerable amounts of band-aid, but the net effect is a
277 saner and more robust implementation.
278
279- Made a bunch of symbols static that were accidentally global.
280
281Build and Ports
282
283- The setup.py script didn't check for a new enough version of zlib
284 (1.1.3 is needed). Now it does.
285
286- Changed "make clean" target to also remove shared libraries.
287
288- Added a more general warning about the SGI Irix optimizer to README.
289
290Library
291
292- Fix a bug in urllib.basejoin("http://host", "../file.html") which
293 omitted the slash between host and file.html.
294
295- The mailbox module's _Mailbox class contained a completely broken
296 and undocumented seek() method. Ripped it out.
297
298- Fixed a bunch of typos in various library modules (urllib2, smtpd,
299 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
300
301- Fixed a few last-minute bugs in unittest.
302
303Extensions
304
305- Reverted the patch to the OpenSSL code in socketmodule.c to support
306 RAND_status() and the EGD, and the subsequent patch that tried to
307 fix it for pre-0.9.5 versions; the problem with the patch is that on
308 some systems it issues a warning whenever socket is imported, and
309 that's unacceptable.
310
311Tests
312
313- Fixed the pickle tests to work with "import test.test_pickle".
314
315- Tweaked test_locale.py to actually run the test Windows.
316
317- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
318 not "wb" (which is not a valid mode at all).
319
320- Fix pstats browser crashes. Import readline if it exists to make
321 the user interface nicer.
322
323- Add "import thread" to the top of test modules that import the
324 threading module (test_asynchat and test_threadedtempfile). This
325 prevents test failures caused by a broken threading module resulting
326 from a previously caught failed import.
327
328- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
329 needed on some platforms (e.g. Solaris 8) when the tests are run
330 twice in succession.
331
332- Skip rather than fail test_sunaudiodev if no audio device is found.
333
334
335What's New in Python 2.1c1?
336===========================
337
338This list was significantly updated when 2.1c2 was released; the 2.1c1
339release didn't mention most changes that were actually part of 2.1c1:
340
341Legal
342
343- Copyright was assigned to the Python Software Foundation (PSF) and a
344 PSF license (very similar to the CNRI license) was added.
345
346- The CNRI copyright notice was updated to include 2001.
347
348Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000349
Guido van Rossumc9932722001-04-12 02:31:27 +0000350- After a public outcry, assignment to __debug__ is no longer illegal;
351 instead, a warning is issued. It will become illegal in 2.2.
352
Guido van Rossum5b08f132001-04-16 02:05:23 +0000353- Fixed a core dump with "%#x" % 0, and changed the semantics so that
354 "%#x" now always prepends "0x", even if the value is zero.
355
356- Fixed some nits in the bytecode compiler.
357
358- Fixed core dumps when calling certain kinds of non-functions.
359
360- Fixed various core dumps caused by reference count bugs.
361
362Build and Ports
363
364- Use INSTALL_SCRIPT to install script files.
365
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000366- New port: SCO Unixware 7, by Billy G. Allie.
367
Guido van Rossum5b08f132001-04-16 02:05:23 +0000368- Updated RISCOS port.
369
370- Updated BeOS port and notes.
371
372- Various other porting problems resolved.
373
374Library
375
376- The TERMIOS and SOCKET modules are now truly obsolete and
377 unnecessary. Their symbols are incorporated in the termios and
378 socket modules.
379
380- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
381 better tests for pickling.
382
383- threading: make Condition.wait() robust against KeyboardInterrupt.
384
385- zipfile: add support to zipfile to support opening an archive
386 represented by an open file rather than a file name. Fix bug where
387 the archive was not properly closed. Fixed a bug in this bugfix
388 where flush() was called for a read-only file.
389
390- imputil: added an uninstall() method to the ImportManager.
391
392- Canvas: fixed bugs in lower() and tkraise() methods.
393
394- SocketServer: API change (added overridable close_request() method)
395 so that the TCP server can explicitly close the request.
396
397- pstats: Eric Raymond added a simple interactive statistics browser,
398 invoked when the module is run as a script.
399
400- locale: fixed a problem in format().
401
402- webbrowser: made it work when the BROWSER environment variable has a
403 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
404 KDE 2. Fixed some other nits.
405
406- unittest: changes to allow using a different exception than
407 AssertionError, and added a few more function aliases. Some other
408 small changes.
409
410- urllib, urllib2: fixed redirect problems and a coupleof other nits.
411
412- asynchat: fixed a critical bug in asynchat that slipped through the
413 2.1b2 release. Fixed another rare bug.
414
415- Fix some unqualified except: clauses (always a bad code example).
416
417XML
418
419- pyexpat: new API get_version_string().
420
421- Fixed some minidom bugs.
422
423Extensions
424
425- Fixed a core dump in _weakref. Removed the weakref.mapping()
426 function (it adds nothing to the API).
427
428- Rationalized the use of header files in the readline module, to make
429 it compile (albeit with some warnings) with the very recent readline
430 4.2, without breaking for earlier versions.
431
432- Hopefully fixed a buffering problem in linuxaudiodev.
433
434- Attempted a fix to make the OpenSSL support in the socket module
435 work again with pre-0.9.5 versions of OpenSSL.
436
437Tests
438
439- Added a test case for asynchat and asyncore.
440
441- Removed coupling between tests where one test failing could break
442 another.
443
444Tools
445
446- Ping added an interactive help browser to pydoc, fixed some nits
447 in the rest of the pydoc code, and added some features to his
448 inspect module.
449
450- An updated python-mode.el version 4.1 which integrates Ken
451 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
452 much nicer in XEmacs and Emacs. When stepping through your program
453 with pdb, in either the shell window or the *Python* window, the
454 source file and line will be tracked by an arrow. Very cool!
455
456- IDLE: syntax warnings in interactive mode are changed into errors.
457
458- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000459 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000460
461- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000462
Barry Warsaw11e89c72001-04-11 20:37:57 +0000463
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000464What's New in Python 2.1 beta 2?
465================================
466
Guido van Rossum053ae352001-03-22 14:17:21 +0000467(Unlisted are many fixed bugs, more documentation, etc.)
468
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000469Core language, builtins, and interpreter
470
Guido van Rossum053ae352001-03-22 14:17:21 +0000471- The nested scopes work (enabled by "from __future__ import
472 nested_scopes") is completed; in particular, the future now extends
473 into code executed through exec, eval() and execfile(), and into the
474 interactive interpreter.
475
476- When calling a base class method (e.g. BaseClass.__init__(self)),
477 this is now allowed even if self is not strictly spoken a class
478 instance (e.g. when using metaclasses or the Don Beaudry hook).
479
480- Slice objects are now comparable but not hashable; this prevents
481 dict[:] from being accepted but meaningless.
482
483- Complex division is now calculated using less braindead algorithms.
484 This doesn't change semantics except it's more likely to give useful
485 results in extreme cases. Complex repr() now uses full precision
486 like float repr().
487
488- sgmllib.py now calls handle_decl() for simple <!...> declarations.
489
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000490- It is illegal to assign to the name __debug__, which is set when the
491 interpreter starts. It is effectively a compile-time constant.
492
493- A warning will be issued if a global statement for a variable
494 follows a use or assignment of that variable.
495
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000496Standard library
497
Guido van Rossum053ae352001-03-22 14:17:21 +0000498- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
499 inspired by JUnit), is now part of the standard library. You now
500 have a choice of two testing frameworks: unittest requires you to
501 write testcases as separate code, doctest gathers them from
502 docstrings. Both approaches have their advantages and
503 disadvantages.
504
505- A new module Tix was added, which wraps the Tix extension library
506 for Tk. With that module, it is not necessary to statically link
507 Tix with _tkinter, since Tix will be loaded with Tcl's "package
508 require" command. See Demo/tix/.
509
510- tzparse.py is now obsolete.
511
512- In gzip.py, the seek() and tell() methods are removed -- they were
513 non-functional anyway, and it's better if callers can test for their
514 existence with hasattr().
515
516Python/C API
517
518- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
519 that's already in the dictionary during a PyDict_Next() iteration.
520 This used to fail occasionally when a dictionary resize operation
521 could be triggered that would rehash all the keys. All other
522 modifications to the dictionary are still off-limits during a
523 PyDict_Next() iteration!
524
525- New extended APIs related to passing compiler variables around.
526
527- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
528 implement isinstance() and issubclass().
529
530- Py_BuildValue() now has a "D" conversion to create a Python complex
531 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000532
Fred Drake4e262a92001-03-22 18:26:47 +0000533- Extensions types which support weak references must now set the
534 field allocated for the weak reference machinery to NULL themselves;
535 this is done to avoid the cost of checking each object for having a
536 weakly referencable type in PyObject_INIT(), since most types are
537 not weakly referencable.
538
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000539- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
540 free variables and cell variables to and from the frame's f_locals.
541
542- Variants of several functions defined in pythonrun.h have been added
543 to support the nested_scopes future statement. The variants all end
544 in Flags and take an extra argument, a PyCompilerFlags *; examples:
545 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
546 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000547 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000548
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000549Distutils
550
551- the sdist command now writes a PKG-INFO file, as described in PEP 241,
552 into the release tree.
553
Tim Peters0e57abf2001-05-02 07:39:38 +0000554- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000555 (an uninstaller, more customization of the installer's display)
556
557- from Jack Jansen: added Mac-specific code to generate a dialog for
558 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000559 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000560 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000561
562- added 'platforms' and 'keywords' to the set of metadata that can be
563 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000564
565- applied patches from Jason Tishler to make the compiler class work with
566 Cygwin.
567
568
Tim Peters2fe289a2001-03-01 22:19:38 +0000569What's New in Python 2.1 beta 1?
570================================
Tim Petersd66595f2001-02-04 03:09:53 +0000571
572Core language, builtins, and interpreter
573
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000574- Following an outcry from the community about the amount of code
575 broken by the nested scopes feature introduced in 2.1a2, we decided
576 to make this feature optional, and to wait until Python 2.2 (or at
577 least 6 months) to make it standard. The option can be enabled on a
578 per-module basis by adding "from __future__ import nested_scopes" at
579 the beginning of a module (before any other statements, but after
580 comments and an optional docstring). See PEP 236 (Back to the
581 __future__) for a description of the __future__ statement. PEP 227
582 (Statically Nested Scopes) has been updated to reflect this change,
583 and to clarify the semantics in a number of endcases.
584
585- The nested scopes code, when enabled, has been hardened, and most
586 bugs and memory leaks in it have been fixed.
587
588- Compile-time warnings are now generated for a number of conditions
589 that will break or change in meaning when nested scopes are enabled:
590
591 - Using "from...import *" or "exec" without in-clause in a function
592 scope that also defines a lambda or nested function with one or
593 more free (non-local) variables. The presence of the import* or
594 bare exec makes it impossible for the compiler to determine the
595 exact set of local variables in the outer scope, which makes it
596 impossible to determine the bindings for free variables in the
597 inner scope. To avoid the warning about import *, change it into
598 an import of explicitly name object, or move the import* statement
599 to the global scope; to avoid the warning about bare exec, use
600 exec...in... (a good idea anyway -- there's a possibility that
601 bare exec will be deprecated in the future).
602
603 - Use of a global variable in a nested scope with the same name as a
604 local variable in a surrounding scope. This will change in
605 meaning with nested scopes: the name in the inner scope will
606 reference the variable in the outer scope rather than the global
607 of the same name. To avoid the warning, either rename the outer
608 variable, or use a global statement in the inner function.
609
Neil Schemenauera35c6882001-02-27 04:45:05 +0000610- An optional object allocator has been included. This allocator is
611 optimized for Python objects and should be faster and use less memory
612 than the standard system allocator. It is not enabled by default
613 because of possible thread safety problems. The allocator is only
614 protected by the Python interpreter lock and it is possible that some
615 extension modules require a thread safe allocator. The object
616 allocator can be enabled by providing the "--with-pymalloc" option to
617 configure.
618
Tim Petersd66595f2001-02-04 03:09:53 +0000619Standard library
620
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000621- pyexpat now detects the expat version if expat.h defines it. A
622 number of additional handlers are provided, which are only available
623 since expat 1.95. In addition, the methods SetParamEntityParsing and
624 GetInputContext of Parser objects are available with 1.95.x
625 only. Parser objects now provide the ordered_attributes and
626 specified_attributes attributes. A new module expat.model was added,
627 which offers a number of additional constants if 1.95.x is used.
628
629- xml.dom offers the new functions registerDOMImplementation and
630 getDOMImplementation.
631
632- xml.dom.minidom offers a toprettyxml method. A number of DOM
633 conformance issues have been resolved. In particular, Element now
634 has an hasAttributes method, and the handling of namespaces was
635 improved.
636
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000637- Ka-Ping Yee contributed two new modules: inspect.py, a module for
638 getting information about live Python code, and pydoc.py, a module
639 for interactively converting docstrings to HTML or text.
640 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000641 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000642 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
643 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000644
Tim Peters1eff7962001-03-01 02:31:33 +0000645- New library module difflib.py, primarily packaging the SequenceMatcher
646 class at the heart of the popular ndiff.py file-comparison tool.
647
648- doctest.py (a framework for verifying Python code examples in docstrings)
649 is now part of the std library.
650
Tim Petersd66595f2001-02-04 03:09:53 +0000651Windows changes
652
Guido van Rossume3955a82001-03-02 14:05:59 +0000653- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
654 small GUI that lets you browse the module docstrings using your
655 default web browser.
656
Tim Peters1eff7962001-03-01 02:31:33 +0000657- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
658 Platforms) is implemented. See
659
660 http://python.sourceforge.net/peps/pep-0235.html
661
662 for full details, especially the "Current Lower-Left Semantics" section.
663 The new Windows import rules are simpler than before:
664
665 A. If the PYTHONCASEOK environment variable exists, same as
666 before: silently accept the first case-insensitive match of any
667 kind; raise ImportError if none found.
668
669 B. Else search sys.path for the first case-sensitive match; raise
670 ImportError if none found.
671
672 The same rules have been implented on other platforms with case-
673 insensitive but case-preserving filesystems too (including Cygwin, and
674 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000675
Tim Peters25a9ce32001-02-19 07:06:36 +0000676- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
677 what it's supposed to do (and does do under NT and 2000) via direct
678 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000679 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000680 all Win9x systems before.
681
Tim Peters1eff7962001-03-01 02:31:33 +0000682- Build: Subproject _test (effectively) renamed to _testcapi.
683
Tim Peters2fe289a2001-03-01 22:19:38 +0000684New platforms
685
686- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
687 Thanks to Steven Majewski!
688
689- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
690 Tishler!
691
Guido van Rossum9089b272001-03-02 06:49:50 +0000692- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
693 Schwertberger! See RISCOS/README for more information -- it seems
694 that because of the bizarre filename conventions on RISCOS, no port
695 to that platform is easy. Note that the new variable os.endsep is
696 silently supported in order to make life easier on this platform,
697 but we don't advertise it because it's not worth for most folks to
698 care about RISCOS portability.
699
Tim Peters25a9ce32001-02-19 07:06:36 +0000700
Tim Petersd7b5e882001-01-25 03:36:26 +0000701What's New in Python 2.1 alpha 2?
702=================================
Tim Peters40ead762001-01-27 05:35:26 +0000703
Tim Petersd7b5e882001-01-25 03:36:26 +0000704Core language, builtins, and interpreter
705
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000706- Scopes nest. If a name is used in a function or class, but is not
707 local, the definition in the nearest enclosing function scope will
708 be used. One consequence of this change is that lambda statements
709 could reference variables in the namespaces where the lambda is
710 defined. In some unusual cases, this change will break code.
711
712 In all previous version of Python, names were resolved in exactly
713 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000714 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000715 function A is defined within a function B, the names bound in B are
716 not visible in A. The new rules make names bound in B visible in A,
717 unless A contains a name binding that hides the binding in B.
718
719 Section 4.1 of the reference manual describes the new scoping rules
720 in detail. The test script in Lib/test/test_scope.py demonstrates
721 some of the effects of the change.
722
723 The new rules will cause existing code to break if it defines nested
724 functions where an outer function has local variables with the same
725 name as globals or builtins used by the inner function. Example:
726
727 def munge(str):
728 def helper(x):
729 return str(x)
730 if type(str) != type(''):
731 str = helper(str)
732 return str.strip()
733
734 Under the old rules, the name str in helper() is bound to the
735 builtin function str(). Under the new rules, it will be bound to
736 the argument named str and an error will occur when helper() is
737 called.
738
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000739- The compiler will report a SyntaxError if "from ... import *" occurs
740 in a function or class scope. The language reference has documented
741 that this case is illegal, but the compiler never checked for it.
742 The recent introduction of nested scope makes the meaning of this
743 form of name binding ambiguous. In a future release, the compiler
744 may allow this form when there is no possibility of ambiguity.
745
Tim Peters40ead762001-01-27 05:35:26 +0000746- repr(string) is easier to read, now using hex escapes instead of octal,
747 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
748
749 >>> "\texample \r\n" + chr(0) + chr(255)
750 '\texample \r\n\x00\xff' # in 2.1
751 '\011example \015\012\000\377' # in 2.0
752
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000753- Functions are now compared and hashed by identity, not by value, since
754 the func_code attribute is writable.
755
Fred Drakefb9d7122001-02-01 20:00:40 +0000756- Weak references (PEP 205) have been added. This involves a few
757 changes in the core, an extension module (_weakref), and a Python
758 module (weakref). The weakref module is the public interface. It
759 includes support for "explicit" weak references, proxy objects, and
760 mappings with weakly held values.
761
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000762- A 'continue' statement can now appear in a try block within the body
763 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000764 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000765
Tim Petersd7b5e882001-01-25 03:36:26 +0000766Standard library
767
Barry Warsaw30dbd142001-01-31 22:14:01 +0000768- mailbox.py now has a new class, PortableUnixMailbox which is
769 identical to UnixMailbox but uses a more portable scheme for
770 determining From_ separators. Also, the constructors for all the
771 classes in this module have a new optional `factory' argument, which
772 is a callable used when new message classes must be instantiated by
773 the next() method.
774
Tim Petersd7b5e882001-01-25 03:36:26 +0000775- random.py is now self-contained, and offers all the functionality of
776 the now-deprecated whrandom.py. See the docs for details. random.py
777 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000778 and restoring the internal state of the generator; and jumpahead(n),
779 for quickly forcing the internal state to be the same as if n calls to
780 random() had been made. The latter is particularly useful for multi-
781 threaded programs, creating one instance of the random.Random() class for
782 each thread, then using .jumpahead() to force each instance to use a
783 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000784
Tim Peters0de88fc2001-02-01 04:59:18 +0000785- random.py's seed() function is new. For bit-for-bit compatibility with
786 prior releases, use the whseed function instead. The new seed function
787 addresses two problems: (1) The old function couldn't produce more than
788 about 2**24 distinct internal states; the new one about 2**45 (the best
789 that can be done in the Wichmann-Hill generator). (2) The old function
790 sometimes produced identical internal states when passed distinct
791 integers, and there was no simple way to predict when that would happen;
792 the new one guarantees to produce distinct internal states for all
793 arguments in [0, 27814431486576L).
794
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000795- The socket module now supports raw packets on Linux. The socket
796 family is AF_PACKET.
797
Tim Peters9ea17ac2001-02-02 05:57:15 +0000798- test_capi.py is a start at running tests of the Python C API. The tests
799 are implemented by the new Modules/_testmodule.c.
800
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000801- A new extension module, _symtable, provides provisional access to the
802 internal symbol table used by the Python compiler. A higher-level
803 interface will be added on top of _symtable in a future release.
804
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000805- Removed the obsolete soundex module.
806
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000807- xml.dom.minidom now uses the standard DOM exceptions. Node supports
808 the isSameNode method; NamedNodeMap the get method.
809
810- xml.sax.expatreader supports the lexical handler property; it
811 generates comment, startCDATA, and endCDATA events.
812
Tim Petersee826f82001-01-31 19:39:44 +0000813Windows changes
814
815- Build procedure: the zlib project is built in a different way that
816 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000817 the zlib binary used. See PCbuild\readme.txt for details. Your old
818 zlib-related directories can be deleted; you'll need to download fresh
819 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000820
Tim Peters9ea17ac2001-02-02 05:57:15 +0000821- Build: New subproject _test for the benefit of test_capi.py (see above).
822
Tim Petersb16c56f2001-02-02 21:24:51 +0000823- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
824 interface to some Python compiler internals).
825
826- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000827 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000828
Tim Petersa3a3a032000-11-30 05:22:44 +0000829What's New in Python 2.1 alpha 1?
830=================================
831
832Core language, builtins, and interpreter
833
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000834- There is a new Unicode companion to the PyObject_Str() API
835 called PyObject_Unicode(). It behaves in the same way as the
836 former, but assures that the returned value is an Unicode object
837 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000838
Guido van Rossumf98eda02001-01-17 15:54:45 +0000839- The comparison operators support "rich comparison overloading" (PEP
840 207). C extension types can provide a rich comparison function in
841 the new tp_richcompare slot in the type object. The cmp() function
842 and the C function PyObject_Compare() first try the new rich
843 comparison operators before trying the old 3-way comparison. There
844 is also a new C API PyObject_RichCompare() (which also falls back on
845 the old 3-way comparison, but does not constrain the outcome of the
846 rich comparison to a Boolean result).
847
848 The rich comparison function takes two objects (at least one of
849 which is guaranteed to have the type that provided the function) and
850 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
851 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
852 object, which may be NotImplemented (in which case the tp_compare
853 slot function is used as a fallback, if defined).
854
855 Classes can overload individual comparison operators by defining one
856 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000857 __ge__. There are no explicit "reflected argument" versions of
858 these; instead, __lt__ and __gt__ are each other's reflection,
859 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
860 reflection (similar at the C level). No other implications are
861 made; in particular, Python does not assume that == is the Boolean
862 inverse of !=, or that < is the Boolean inverse of >=. This makes
863 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000864
865 Classes or types that want to implement (in)equality tests but not
866 the ordering operators (i.e. unordered types) should implement ==
867 and !=, and raise an error for the ordering operators.
868
Guido van Rossuma88479f2001-01-18 14:28:08 +0000869 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000870 Boolean; e.g. a matrix type might want to return a matrix of bits
871 for A < B, giving elementwise comparisons. Such types should ensure
872 that any interpretation of their value in a Boolean context raises
873 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
874 at the C level) to always raise an exception.
875
Guido van Rossuma88479f2001-01-18 14:28:08 +0000876- Complex numbers use rich comparisons to define == and != but raise
877 an exception for <, <=, > and >=. Unfortunately, this also means
878 that cmp() of two complex numbers raises an exception when the two
879 numbers differ. Since it is not mathematically meaningful to compare
880 complex numbers except for equality, I hope that this doesn't break
881 too much code.
882
Tim Peters3389f192001-02-18 08:48:49 +0000883- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000884 not defined by the language, other than that it's arbitrary but
885 consistent (see the Reference Manual). An implementation detail changed
886 in 2.1a1 such that None now compares less than any other object. Code
887 relying on this new behavior (like code that relied on the previous
888 behavior) does so at its own risk.
889
Barry Warsaw573b5412001-01-15 20:43:18 +0000890- Functions and methods now support getting and setting arbitrarily
891 named attributes (PEP 232). Functions have a new __dict__
892 (a.k.a. func_dict) which hold the function attributes. Methods get
893 and set attributes on their underlying im_func. It is a TypeError
894 to set an attribute on a bound method.
895
Guido van Rossum051e3352001-01-15 19:11:10 +0000896- The xrange() object implementation has been improved so that
897 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
898 limitation that in this case len(xrange(sys.maxint)) can't be
899 calculated, but the common idiom "for i in xrange(sys.maxint)" will
900 work fine as long as the index i doesn't actually reach 2**31.
901 (Python uses regular ints for sequence and string indices; fixing
902 that is much more work.)
903
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000904- Two changes to from...import:
905
Guido van Rossumba381232001-02-03 15:06:40 +0000906 1) "from M import X" now works even if (after loading module M)
907 sys.modules['M'] is not a real module; it's basically a getattr()
908 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000909
910 2) "from M import *" now looks for M.__all__ to decide which names to
911 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
912 filters out names starting with '_' as before. Whether or not
913 __all__ exists, there's no restriction on the type of M.
914
Guido van Rossumf61f1662001-01-10 20:13:55 +0000915- File objects have a new method, xreadlines(). This is the fastest
916 way to iterate over all lines in a file:
917
918 for line in file.xreadlines():
919 ...do something to line...
920
921 See the xreadlines module (mentioned below) for how to do this for
922 other file-like objects.
923
924- Even if you don't use file.xreadlines(), you may expect a speedup on
925 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000926 quite a bit in platform-specific ways: on systems (like Linux) that
927 support flockfile(), getc_unlocked(), and funlockfile(), those are
928 used by default. On systems (like Windows) without getc_unlocked(),
929 a complicated (but still thread-safe) method using fgets() is used by
930 default.
931
Tim Petersd52269b2001-01-25 06:23:18 +0000932 You can force use of the fgets() method by #define'ing
933 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000934 getc_unlocked()).
935
Tim Petersd52269b2001-01-25 06:23:18 +0000936 You can force fgets() not to be used by #define'ing
937 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000938 test_bufio.py fails -- and let us know if it does!).
939
940- In addition, the fileinput module, while still slower than the other
941 methods on most platforms, has been sped up too, by using
942 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000943
944- Support for run-time warnings has been added, including a new
945 command line option (-W) to specify the disposition of warnings.
946 See the description of the warnings module below.
947
948- Extensive changes have been made to the coercion code. This mostly
949 affects extension modules (which can now implement mixed-type
950 numerical operators without having to use coercion), but
951 occasionally, in boundary cases the coercion semantics have changed
952 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000953 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000954 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000955 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000956
Guido van Rossumf98eda02001-01-17 15:54:45 +0000957- In connection with the coercion changes, a new built-in singleton
958 object, NotImplemented is defined. This can be returned for
959 operations that wish to indicate they are not implemented for a
960 particular combination of arguments. From C, this is
961 Py_NotImplemented.
962
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000963- The interpreter accepts now bytecode files on the command line even
964 if they do not have a .pyc or .pyo extension. On Linux, after executing
965
Martin v. Löwise214baa2001-02-04 22:37:56 +0000966import imp,sys,string
967magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
968reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
969open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000970
971 any byte code file can be used as an executable (i.e. as an argument
972 to execve(2)).
973
Tim Peters9940b802000-12-01 07:59:35 +0000974- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000975 character. In 1.6 and earlier, they never produced a sign,
976 and raised an error if the value of the long was too large
977 to fit in a Python int. In 2.0, they produced a sign if and
978 only if too large to fit in an int. This was inconsistent
979 across platforms (because the size of an int varies across
980 platforms), and inconsistent with hex() and oct(). Example:
981
982 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000983 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000984 'ffffffbe' # in 2.0 and before, on 32-bit machines
985 >>> hex(-0x42L)
986 '-0x42L' # in all versions of Python
987
Tim Peters9940b802000-12-01 07:59:35 +0000988 The behavior of %d formats for negative Python longs remains
989 the same as in 2.0 (although in 1.6 and before, they raised
990 an error if the long didn't fit in a Python int).
991
992 %u formats don't make sense for Python longs, but are allowed
993 and treated the same as %d in 2.1. In 2.0, a negative long
994 formatted via %u produced a sign if and only if too large to
995 fit in an int. In 1.6 and earlier, a negative long formatted
996 via %u raised an error if it was too big to fit in an int.
997
Guido van Rossum3661d392000-12-12 22:10:31 +0000998- Dictionary objects have an odd new method, popitem(). This removes
999 an arbitrary item from the dictionary and returns it (in the form of
1000 a (key, value) pair). This can be useful for algorithms that use a
1001 dictionary as a bag of "to do" items and repeatedly need to pick one
1002 item. Such algorithms normally end up running in quadratic time;
1003 using popitem() they can usually be made to run in linear time.
1004
Tim Peters36cdad12000-12-29 02:06:45 +00001005Standard library
1006
Thomas Woutersfe385252001-01-19 23:16:56 +00001007- In the time module, the time argument to the functions strftime,
1008 localtime, gmtime, asctime and ctime is now optional, defaulting to
1009 the current time (in the local timezone).
1010
Guido van Rossumda91f222001-01-15 16:36:08 +00001011- The ftplib module now defaults to passive mode, which is deemed a
1012 more useful default given that clients are often inside firewalls
1013 these days. Note that this could break if ftplib is used to connect
1014 to a *server* that is inside a firewall, from outside; this is
1015 expected to be a very rare situation. To fix that, you can call
1016 ftp.set_pasv(0).
1017
Martin v. Löwis10a27872001-01-13 09:54:41 +00001018- The module site now treats .pth files not only for path configuration,
1019 but also supports extensions to the initialization code: Lines starting
1020 with import are executed.
1021
Guido van Rossumf61f1662001-01-10 20:13:55 +00001022- There's a new module, warnings, which implements a mechanism for
1023 issuing and filtering warnings. There are some new built-in
1024 exceptions that serve as warning categories, and a new command line
1025 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1026 turns warnings into errors). warnings.warn(message[, category])
1027 issues a warning message; this can also be called from C as
1028 PyErr_Warn(category, message).
1029
1030- A new module xreadlines was added. This exports a single factory
1031 function, xreadlines(). The intention is that this code is the
1032 absolutely fastest way to iterate over all lines in an open
1033 file(-like) object:
1034
1035 import xreadlines
1036 for line in xreadlines.xreadlines(file):
1037 ...do something to line...
1038
1039 This is equivalent to the previous the speed record holder using
1040 file.readlines(sizehint). Note that if file is a real file object
1041 (as opposed to a file-like object), this is equivalent:
1042
1043 for line in file.xreadlines():
1044 ...do something to line...
1045
Tim Peters36cdad12000-12-29 02:06:45 +00001046- The bisect module has new functions bisect_left, insort_left,
1047 bisect_right and insort_right. The old names bisect and insort
1048 are now aliases for bisect_right and insort_right. XXX_right
1049 and XXX_left methods differ in what happens when the new element
1050 compares equal to one or more elements already in the list: the
1051 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001052 right. Code that doesn't care where equal elements end up should
1053 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001054
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001055- The new curses.panel module wraps the panel library that forms part
1056 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1057
Guido van Rossumf61f1662001-01-10 20:13:55 +00001058- The SocketServer module now sets the allow_reuse_address flag by
1059 default in the TCPServer class.
1060
1061- A new function, sys._getframe(), returns the stack frame pointer of
1062 the caller. This is intended only as a building block for
1063 higher-level mechanisms such as string interpolation.
1064
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001065- The pyexpat module supports a number of new handlers, which are
1066 available only in expat 1.2. If invocation of a callback fails, it
1067 will report an additional frame in the traceback. Parser objects
1068 participate now in garbage collection. If expat reports an unknown
1069 encoding, pyexpat will try to use a Python codec; that works only
1070 for single-byte charsets. The parser type objects is exposed as
1071 XMLParserObject.
1072
1073- xml.dom now offers standard definitions for symbolic node type and
1074 exception code constants, and a hierarchy of DOM exceptions. minidom
1075 was adjusted to use them.
1076
1077- The conformance of xml.dom.minidom to the DOM specification was
1078 improved. It detects a number of additional error cases; the
1079 previous/next relationship works even when the tree is modified;
1080 Node supports the normalize() method; NamedNodeMap, DocumentType and
1081 DOMImplementation classes were added; Element supports the
1082 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1083 method.
1084
Guido van Rossumf61f1662001-01-10 20:13:55 +00001085Build issues
1086
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001087- For Unix (and Unix-compatible) builds, configuration and building of
1088 extension modules is now greatly automated. Rather than having to
1089 edit the Modules/Setup file to indicate which modules should be
1090 built and where their include files and libraries are, a
1091 distutils-based setup.py script now takes care of building most
1092 extension modules. All extension modules built this way are built
1093 as shared libraries. Only a few modules that must be linked
1094 statically are still listed in the Setup file; you won't need to
1095 edit their configuration.
1096
1097- Python should now build out of the box on Cygwin. If it doesn't,
1098 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001099
1100- Python now always uses its own (renamed) implementation of getopt()
1101 -- there's too much variation among C library getopt()
1102 implementations.
1103
1104- C++ compilers are better supported; the CXX macro is always set to a
1105 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001106
Tim Petersd92dfe02000-12-12 01:18:41 +00001107Windows changes
1108
1109- select module: By default under Windows, a select() call
1110 can specify no more than 64 sockets. Python now boosts
1111 this Microsoft default to 512. If you need even more than
1112 that, see the MS docs (you'll need to #define FD_SETSIZE
1113 and recompile Python from source).
1114
Guido van Rossumf61f1662001-01-10 20:13:55 +00001115- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1116 subdirectory is no more!
1117
Tim Petersa3a3a032000-11-30 05:22:44 +00001118
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001119What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001120=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001121
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001122Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001123changes are in the file HISTORY. If you are making the jump directly
1124from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1125HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001126
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001127Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1128the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1129http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001130
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001131--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001132
1133======================================================================
1134
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001135What's new in 2.0 (since release candidate 1)?
1136==============================================
1137
1138Standard library
1139
1140- The copy_reg module was modified to clarify its intended use: to
1141 register pickle support for extension types, not for classes.
1142 pickle() will raise a TypeError if it is passed a class.
1143
1144- Fixed a bug in gettext's "normalize and expand" code that prevented
1145 it from finding an existing .mo file.
1146
1147- Restored support for HTTP/0.9 servers in httplib.
1148
Tim Peters989b7b92000-10-16 20:24:53 +00001149- The math module was changed to stop raising OverflowError in case of
1150 underflow, and return 0 instead in underflow cases. Whether Python
1151 used to raise OverflowError in case of underflow was platform-
1152 dependent (it did when the platform math library set errno to ERANGE
1153 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001154
1155- Fixed a bug in StringIO that occurred when the file position was not
1156 at the end of the file and write() was called with enough data to
1157 extend past the end of the file.
1158
1159- Fixed a bug that caused Tkinter error messages to get lost on
1160 Windows. The bug was fixed by replacing direct use of
1161 interp->result with Tcl_GetStringResult(interp).
1162
1163- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1164 redirect response.
1165
1166- Several changes were made to distutils: Some debugging code was
1167 removed from util. Fixed the installer used when an external zip
1168 program (like WinZip) is not found; the source code for this
1169 installer is in Misc/distutils. check_lib() was modified to behave
1170 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1171 test for whether installed modules are on sys.path was changed to
1172 use both normcase() and normpath().
1173
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001174- Several minor bugs were fixed in the xml package (the minidom,
1175 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001176
1177- The regression test driver (regrtest.py) behavior when invoked with
1178 -l changed: It now reports a count of objects that are recognized as
1179 garbage but not freed by the garbage collector.
1180
Tim Peters989b7b92000-10-16 20:24:53 +00001181- The regression test for the math module was changed to test
1182 exceptional behavior when the test is run in verbose mode. Python
1183 cannot yet guarantee consistent exception behavior across platforms,
1184 so the exception part of test_math is run only in verbose mode, and
1185 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001186
1187Internals
1188
1189- PyOS_CheckStack() has been disabled on Win64, where it caused
1190 test_sre to fail.
1191
1192Build issues
1193
1194- Changed compiler flags, so that gcc is always invoked with -Wall and
1195 -Wstrict-prototypes. Users compiling Python with GCC should see
1196 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001197 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001198 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001199
Tim Petersa3a3a032000-11-30 05:22:44 +00001200- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001201
1202Tools and other miscellany
1203
1204- The compiler in Tools/compiler was updated to support the new
1205 language features introduced in 2.0: extended print statement, list
1206 comprehensions, and augmented assignments. The new compiler should
1207 also be backwards compatible with Python 1.5.2; the compiler will
1208 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001209 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001210
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001211What's new in 2.0 release candidate 1 (since beta 2)?
1212=====================================================
1213
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001214What is release candidate 1?
1215
1216We believe that release candidate 1 will fix all known bugs that we
1217intend to fix for the 2.0 final release. This release should be a bit
1218more stable than the previous betas. We would like to see even more
1219widespread testing before the final release, so we are producing this
1220release candidate. The final release will be exactly the same unless
1221any show-stopping (or brown bag) bugs are found by testers of the
1222release candidate.
1223
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001224All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001225to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001226
1227Core language, builtins, and interpreter
1228
1229- A bug that caused crashes when __coerce__ was used with augmented
1230 assignment, e.g. +=, was fixed.
1231
1232- Raise ZeroDivisionError when raising zero to a negative number,
1233 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1234 power operator and the result of math.pow(0.0, -2.0) will vary by
1235 platform. On Linux, it raises a ValueError.
1236
1237- A bug in Unicode string interpolation was fixed that occasionally
1238 caused errors with formats including "%%". For example, the
1239 following expression "%% %s" % u"abc" no longer raises a TypeError.
1240
1241- Compilation of deeply nested expressions raises MemoryError instead
1242 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1243
1244- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1245 rendering them useless. They are now written in binary mode again.
1246
1247Standard library
1248
1249- Keyword arguments are now accepted for most pattern and match object
1250 methods in SRE, the standard regular expression engine.
1251
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001252- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001253 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001254
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001255- Several bugs in the Unicode handling and error handling in _tkinter
1256 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001257
1258- Fix memory management errors in Merge() and Tkapp_Call() routines.
1259
1260- Several changes were made to cStringIO to make it compatible with
1261 the file-like object interface and with StringIO. If operations are
1262 performed on a closed object, an exception is raised. The truncate
1263 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001264 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001265
1266- There were many changes made to the linuxaudiodev module and its
1267 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001268 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001269
1270 Note that this module is named poorly, because it should work
1271 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001272 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001273
1274 The module now raises exceptions when errors occur instead of
1275 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1276 audio) and defines a getptr() method that calls the
1277 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1278
1279- The library_version attribute, introduced in an earlier beta, was
1280 removed because it can not be supported with early versions of the C
1281 readline library, which provides no way to determine the version at
1282 compile-time.
1283
1284- The binascii module is now enabled on Win64.
1285
Tim Peters46446d62000-10-09 21:19:31 +00001286- tokenize.py no longer suffers "recursion depth" errors when parsing
1287 programs with very long string literals.
1288
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001289Internals
1290
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001291- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001292 which is called when the interpreter starts up to determine where
1293 the standard library is installed. These vulnerabilities affect all
1294 previous versions of Python and can be exploited by setting very
1295 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1296 setuid Python script, although use of the wrapper in
1297 Misc/setuid-prog.c will eliminate the vulnerability.
1298
1299- Fixed garbage collection bugs in instance creation that were
1300 triggered when errors occurred during initialization. The solution,
1301 applied in cPickle and in PyInstance_New(), is to call
1302 PyObject_GC_Init() after the initialization of the object's
1303 container attributes is complete.
1304
1305- pyexpat adds definitions of PyModule_AddStringConstant and
1306 PyModule_AddObject if the Python version is less than 2.0, which
1307 provides compatibility with PyXML on Python 1.5.2.
1308
1309- If the platform has a bogus definition for LONG_BIT (the number of
1310 bits in a long), an error will be reported at compile time.
1311
1312- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1313 collection crashes and possibly other, unreported crashes.
1314
1315- Fixed a memory leak in _PyUnicode_Fini().
1316
1317Build issues
1318
1319- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001320 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001321 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001322
1323- The mmap.PAGESIZE constant is now initialized using sysconf when
1324 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1325
1326- The md5 file should now compile on all platforms.
1327
1328- The select module now compiles on platforms that do not define
1329 POLLRDNORM and related constants.
1330
1331- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001332 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001333
Jeremy Hylton10921202000-10-09 18:34:12 +00001334- BeOS: A number of changes were made to the build and installation
1335 process. ar-fake now operates on a directory of object files.
1336 dl_export.h is gone, and its macros now appear on the mwcc command
1337 line during build on PPC BeOS.
1338
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001339- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001340 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001341
1342- Cygwin: Support for shared libraries, Tkinter, and sockets.
1343
1344- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1345
1346Tools and other miscellany
1347
1348- Removed debugging prints from main used with freeze.
1349
Tim Peters46446d62000-10-09 21:19:31 +00001350- IDLE auto-indent no longer crashes when it encounters Unicode
1351 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001352
1353What's new in 2.0 beta 2 (since beta 1)?
1354========================================
1355
1356Core language, builtins, and interpreter
1357
Tim Peters482c0212000-09-26 06:33:09 +00001358- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001359 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001360
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001361- Add -h and -V command line options to print the usage message and
1362 Python version number and exit immediately.
1363
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001364- eval() and exec accept Unicode objects as code parameters.
1365
1366- getattr() and setattr() now also accept Unicode objects for the
1367 attribute name, which are converted to strings using the default
1368 encoding before lookup.
1369
1370- Multiplication on string and Unicode now does proper bounds
1371 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1372 string is too long."
1373
1374- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001375 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001376
Jeremy Hylton1b618592000-09-26 05:32:36 +00001377
1378Standard library and extensions
1379
Guido van Rossum5b08f132001-04-16 02:05:23 +00001380- socket module: the OpenSSL code now adds support for RAND_status()
1381 and EGD (Entropy Gathering Device).
1382
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001383- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001384 argument checking; it still takes no arguments.
1385
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001386- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001387
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001388- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001389
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001390- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001391
1392- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001393 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001394
1395- copy: Copy Unicode objects atomically.
1396
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001397- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001398
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001399- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001400
Fred Drake67233bc2000-09-26 16:40:27 +00001401- dbm: Add get() and setdefault() methods to dbm object. Add constant
1402 `library' to module that names the library used. Added doc strings
1403 and method names to error messages. Uses configure to determine
1404 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1405 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001406
1407- distutils: Update to version 0.9.3.
1408
1409- dl: Add several dl.RTLD_ constants.
1410
1411- fpectl: Now supported on FreeBSD.
1412
1413- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1414 found by the collector will be saved in gc.garbage. This is useful
1415 for debugging a program that creates reference cycles.
1416
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001417- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001418 of HTTP class. Do not close socket on zero-length response. Do not
1419 crash when server sends invalid content-length header.
1420
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001421- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001422
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001423- marshal: When reading a short, sign-extend on platforms where shorts
1424 are bigger than 16 bits. When reading a long, repair the unportable
1425 sign extension that was being done for 64-bit machines. (It assumed
1426 that signed right shift sign-extends.)
1427
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001428- operator: Add contains(), invert(), __invert__() as aliases for
1429 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001430
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001431- os: Add support for popen2() and popen3() on all platforms where
1432 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001433
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001434- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001435 clicking on a file in Explorer (or passing the file name to the
1436 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001437
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001438- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001439 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001440
1441- pickle: Now raises ValueError when an invalid pickle that contains
1442 a non-string repr where a string repr was expected. This behavior
1443 matches cPickle.
1444
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001445- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001446
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001447- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001448
1449- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001450 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001451 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001452
1453- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001454 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001455
1456- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001457 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001458 few cycles during startup since the first call to
1459 setdefaultencoding() will initialize the codec registry and the
1460 encodings package.
1461
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001462- socket: Support for size hint in readlines() method of object returned
1463 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001464
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001465- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001466 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001467 is followed by whitespace.
1468
Tim Petersa3a3a032000-11-30 05:22:44 +00001469- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001470
1471- struct: Check ranges for bytes and shorts.
1472
1473- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001474 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001475
1476- Tkinter: Image objects are now guaranteed to have unique ids. Set
1477 event.delta to zero if Tk version doesn't support mousewheel.
1478 Removed some debugging prints.
1479
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001480- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001481
Fred Drake67233bc2000-09-26 16:40:27 +00001482- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001483 which works around a bug in Norton AntiVirus 2000 that leads directly
1484 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001485
1486- xml: New version detection code allows PyXML to override standard
1487 XML package if PyXML version is greater than 0.6.1.
1488
Fred Drake64bb3802000-09-26 16:21:35 +00001489- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1490 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1491 tree only for nodes which are sufficiently interesting to a specific
1492 application. Does not provide the HTML-specific extensions. Still
1493 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001494
Fred Drake64bb3802000-09-26 16:21:35 +00001495- xml.sax: SAX 2 support for Python, including all the handler
1496 interfaces needed to process XML 1.0 compliant XML. Some
1497 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001498
Fred Drake64bb3802000-09-26 16:21:35 +00001499- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1500 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001501
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001502
Jeremy Hylton1b618592000-09-26 05:32:36 +00001503C API
1504
1505- Add three new convenience functions for module initialization --
1506 PyModule_AddObject(), PyModule_AddIntConstant(), and
1507 PyModule_AddStringConstant().
1508
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001509- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001510 removed and add #error to Python.h if NULL isn't defined after
1511 #include of stdio.h.
1512
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001513- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001514 backwards compatibility (at the source level) with old extensions.
1515
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001516- A wrapper API was added for signal() and sigaction(). Instead of
1517 either function, always use PyOS_getsig() to get a signal handler
1518 and PyOS_setsig() to set one. A new convenience typedef
1519 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001520
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001521- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001522 internal data buffer and size of a string object -- or the default
1523 encoded version of a Unicode object.
1524
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001525- PyString_Size() and PyString_AsString() accept Unicode objects.
1526
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001527- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001528 exists). INT_MAX and LONG_MAX will always be defined, even if
1529 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001530
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001531- PyFloat_FromString takes a second argument, pend, that was
1532 effectively useless. It is now officially useless but preserved for
1533 backwards compatibility. If the pend argument is not NULL, *pend is
1534 set to NULL.
1535
1536- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1537 for the attribute name. See note on getattr() above.
1538
1539- A few bug fixes to argument processing for Unicode.
1540 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1541 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1542 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001543 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001544
1545- Py_BuildValue accepts B format (for bgen-generated code).
1546
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001547
Jeremy Hylton1b618592000-09-26 05:32:36 +00001548Internals
1549
1550- On Unix, fix code for finding Python installation directory so that
1551 it works when argv[0] is a relative path.
1552
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001553- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001554 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001555 rather than by generating a copy of the object.
1556
Tim Peters482c0212000-09-26 06:33:09 +00001557- Several of the internal Unicode tables are much smaller now, and
1558 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001559
Jeremy Hylton97693b02000-09-26 17:42:51 +00001560- In the garbage collector: Fixed bug in collection of tuples. Fixed
1561 bug that caused some instances to be removed from the container set
1562 while they were still live. Fixed parsing in gc.set_debug() for
1563 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001564
1565- Fixed refcount problem in instance deallocation that only occurred
1566 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1567
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001568- On Windows, getpythonregpath is now protected against null data in
1569 registry key.
1570
1571- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001572 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001573
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001574
Jeremy Hylton1b618592000-09-26 05:32:36 +00001575Build and platform-specific issues
1576
1577- Better support of GNU Pth via --with-pth configure option.
1578
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001579- Python/C API now properly exposed to dynamically-loaded extension
1580 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001581
1582- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1583 Don't define MS_SYNC to be zero when it is undefined. Added missing
1584 prototypes in posixmodule.c.
1585
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001586- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001587 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001588
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001589- Fix largefile support on older NetBSD systems and OpenBSD by adding
1590 define for TELL64.
1591
1592
1593Tools and other miscellany
1594
1595- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1596
1597- freeze: The modulefinder now works with 2.0 opcodes.
1598
Tim Petersa3a3a032000-11-30 05:22:44 +00001599- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001600 Move hackery of sys.argv until after the Tk instance has been
1601 created, which allows the application-specific Tkinter
1602 initialization to be executed if present; also pass an explicit
1603 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001604
Jeremy Hylton1b618592000-09-26 05:32:36 +00001605
1606What's new in 2.0 beta 1?
1607=========================
1608
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001609Source Incompatibilities
1610------------------------
1611
1612None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1613such as single-argument append(), connect() and bind(), and changes to
1614str(long) and repr(float).
1615
1616
1617Binary Incompatibilities
1618------------------------
1619
1620- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1621with Python 2.0; these extensions will have to be rebuilt for Python
16222.0.
1623
1624- On Windows, attempting to import a third party extension built for
1625Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1626can do about this. Check your PYTHONPATH environment variable!
1627
1628- Python bytecode files (*.pyc and *.pyo) are not compatible between
1629releases.
1630
1631
1632Overview of Changes Since 1.6
1633-----------------------------
1634
1635There are many new modules (including brand new XML support through
1636the xml package, and i18n support through the gettext module); a list
1637of all new modules is included below. Lots of bugs have been fixed.
1638
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001639The process for making major new changes to the language has changed
1640since Python 1.6. Enhancements must now be documented by a Python
1641Enhancement Proposal (PEP) before they can be accepted.
1642
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001643There are several important syntax enhancements, described in more
1644detail below:
1645
1646 - Augmented assignment, e.g. x += 1
1647
1648 - List comprehensions, e.g. [x**2 for x in range(10)]
1649
1650 - Extended import statement, e.g. import Module as Name
1651
1652 - Extended print statement, e.g. print >> file, "Hello"
1653
1654Other important changes:
1655
1656 - Optional collection of cyclical garbage
1657
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001658Python Enhancement Proposal (PEP)
1659---------------------------------
1660
1661PEP stands for Python Enhancement Proposal. A PEP is a design
1662document providing information to the Python community, or describing
1663a new feature for Python. The PEP should provide a concise technical
1664specification of the feature and a rationale for the feature.
1665
1666We intend PEPs to be the primary mechanisms for proposing new
1667features, for collecting community input on an issue, and for
1668documenting the design decisions that have gone into Python. The PEP
1669author is responsible for building consensus within the community and
1670documenting dissenting opinions.
1671
1672The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001673
1674Augmented Assignment
1675--------------------
1676
1677This must have been the most-requested feature of the past years!
1678Eleven new assignment operators were added:
1679
Guido van Rossume905e952000-09-05 12:42:46 +00001680 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001681
1682For example,
1683
1684 A += B
1685
1686is similar to
1687
1688 A = A + B
1689
1690except that A is evaluated only once (relevant when A is something
1691like dict[index].attr).
1692
1693However, if A is a mutable object, A may be modified in place. Thus,
1694if A is a number or a string, A += B has the same effect as A = A+B
1695(except A is only evaluated once); but if a is a list, A += B has the
1696same effect as A.extend(B)!
1697
1698Classes and built-in object types can override the new operators in
1699order to implement the in-place behavior; the not-in-place behavior is
1700used automatically as a fallback when an object doesn't implement the
1701in-place behavior. For classes, the method name is derived from the
1702method name for the corresponding not-in-place operator by inserting
1703an 'i' in front of the name, e.g. __iadd__ implements in-place
1704__add__.
1705
1706Augmented assignment was implemented by Thomas Wouters.
1707
1708
1709List Comprehensions
1710-------------------
1711
1712This is a flexible new notation for lists whose elements are computed
1713from another list (or lists). The simplest form is:
1714
1715 [<expression> for <variable> in <sequence>]
1716
Guido van Rossum56db0952000-09-06 23:34:25 +00001717For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001718This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001719
1720You can also add a condition:
1721
1722 [<expression> for <variable> in <sequence> if <condition>]
1723
1724For example, [w for w in words if w == w.lower()] would yield the list
1725of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001726than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001727
1728You can also have nested for loops and more than one 'if' clause. For
1729example, here's a function that flattens a sequence of sequences::
1730
1731 def flatten(seq):
1732 return [x for subseq in seq for x in subseq]
1733
1734 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1735
1736This prints
1737
1738 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1739
1740List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001741Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001742
1743
1744Extended Import Statement
1745-------------------------
1746
1747Many people have asked for a way to import a module under a different
1748name. This can be accomplished like this:
1749
1750 import foo
1751 bar = foo
1752 del foo
1753
1754but this common idiom gets old quickly. A simple extension of the
1755import statement now allows this to be written as follows:
1756
1757 import foo as bar
1758
1759There's also a variant for 'from ... import':
1760
1761 from foo import bar as spam
1762
1763This also works with packages; e.g. you can write this:
1764
1765 import test.regrtest as regrtest
1766
1767Note that 'as' is not a new keyword -- it is recognized only in this
1768context (this is only possible because the syntax for the import
1769statement doesn't involve expressions).
1770
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001771Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001772
1773
1774Extended Print Statement
1775------------------------
1776
1777Easily the most controversial new feature, this extension to the print
1778statement adds an option to make the output go to a different file
1779than the default sys.stdout.
1780
1781For example, to write an error message to sys.stderr, you can now
1782write:
1783
1784 print >> sys.stderr, "Error: bad dog!"
1785
1786As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001787evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001788
1789 print >> None, "Hello world"
1790
1791is equivalent to
1792
1793 print "Hello world"
1794
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001795Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001796
1797
1798Optional Collection of Cyclical Garbage
1799---------------------------------------
1800
1801Python is now equipped with a garbage collector that can hunt down
1802cyclical references between Python objects. It's no replacement for
1803reference counting; in fact, it depends on the reference counts being
1804correct, and decides that a set of objects belong to a cycle if all
1805their reference counts can be accounted for from their references to
1806each other. This devious scheme was first proposed by Eric Tiedemann,
1807and brought to implementation by Neil Schemenauer.
1808
1809There's a module "gc" that lets you control some parameters of the
1810garbage collection. There's also an option to the configure script
1811that lets you enable or disable the garbage collection. In 2.0b1,
1812it's on by default, so that we (hopefully) can collect decent user
1813experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001814performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001815off by default in the final 2.0 release.
1816
1817
1818Smaller Changes
1819---------------
1820
1821A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1822map(None, seq1, seq2, ...) when the sequences have the same length;
1823i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1824the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001825zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001826
1827sys.version_info is a tuple (major, minor, micro, level, serial).
1828
1829Dictionaries have an odd new method, setdefault(key, default).
1830dict.setdefault(key, default) returns dict[key] if it exists; if not,
1831it sets dict[key] to default and returns that value. Thus:
1832
1833 dict.setdefault(key, []).append(item)
1834
1835does the same work as this common idiom:
1836
1837 if not dict.has_key(key):
1838 dict[key] = []
1839 dict[key].append(item)
1840
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001841There are two new variants of SyntaxError that are raised for
1842indentation-related errors: IndentationError and TabError.
1843
1844Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1845escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001846
1847The limits on the size of expressions and file in Python source code
1848have been raised from 2**16 to 2**32. Previous versions of Python
1849were limited because the maximum argument size the Python VM accepted
1850was 2**16. This limited the size of object constructor expressions,
1851e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1852limit was raised thanks to a patch by Charles Waldman that effectively
1853fixes the problem. It is now much more likely that you will be
1854limited by available memory than by an arbitrary limit in Python.
1855
1856The interpreter's maximum recursion depth can be modified by Python
1857programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1858limit is the maximum number of recursive calls that can be made by
1859Python code. The limit exists to prevent infinite recursion from
1860overflowing the C stack and causing a core dump. The default value is
18611000. The maximum safe value for a particular platform can be found
1862by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001863
1864New Modules and Packages
1865------------------------
1866
1867atexit - for registering functions to be called when Python exits.
1868
1869imputil - Greg Stein's alternative API for writing custom import
1870hooks.
1871
1872pyexpat - an interface to the Expat XML parser, contributed by Paul
1873Prescod.
1874
1875xml - a new package with XML support code organized (so far) in three
1876subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1877would fill a volume. There's a special feature whereby a
1878user-installed package named _xmlplus overrides the standard
1879xmlpackage; this is intended to give the XML SIG a hook to distribute
1880backwards-compatible updates to the standard xml package.
1881
1882webbrowser - a platform-independent API to launch a web browser.
1883
1884
Guido van Rossume905e952000-09-05 12:42:46 +00001885Changed Modules
1886---------------
1887
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001888array -- new methods for array objects: count, extend, index, pop, and
1889remove
1890
1891binascii -- new functions b2a_hex and a2b_hex that convert between
1892binary data and its hex representation
1893
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001894calendar -- Many new functions that support features including control
1895over which day of the week is the first day, returning strings instead
1896of printing them. Also new symbolic constants for days of week,
1897e.g. MONDAY, ..., SUNDAY.
1898
1899cgi -- FieldStorage objects have a getvalue method that works like a
1900dictionary's get method and returns the value attribute of the object.
1901
1902ConfigParser -- The parser object has new methods has_option,
1903remove_section, remove_option, set, and write. They allow the module
1904to be used for writing config files as well as reading them.
1905
1906ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001907optionally support the RFC 959 REST command.
1908
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001909gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001910
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001911httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1912the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001913
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001914locale -- implement getdefaultlocale for Win32 and Macintosh
1915
1916marshal -- no longer dumps core when marshaling deeply nested or
1917recursive data structures
1918
1919os -- new functions isatty, seteuid, setegid, setreuid, setregid
1920
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001921os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1922support under Unix.
1923
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001924os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001925
1926os.path -- fix semantics of os.path.commonprefix
1927
1928smtplib -- support for sending very long messages
1929
1930socket -- new function getfqdn()
1931
1932readline -- new functions to read, write and truncate history files.
1933The readline section of the library reference manual contains an
1934example.
1935
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001936select -- add interface to poll system call
1937
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001938shutil -- new copyfileobj function
1939
1940SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1941HTTP server.
1942
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001943Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001944
1945urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001946e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001947
1948whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001949
1950
1951Obsolete Modules
1952----------------
1953
1954None. However note that 1.6 made a whole slew of modules obsolete:
1955stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1956poly, zmod, strop, util, whatsound.
1957
1958
1959Changed, New, Obsolete Tools
1960----------------------------
1961
Tim Peters8b092332000-09-05 20:15:25 +00001962None.
Guido van Rossume905e952000-09-05 12:42:46 +00001963
1964
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001965C-level Changes
1966---------------
1967
1968Several cleanup jobs were carried out throughout the source code.
1969
1970All C code was converted to ANSI C; we got rid of all uses of the
1971Py_PROTO() macro, which makes the header files a lot more readable.
1972
1973Most of the portability hacks were moved to a new header file,
1974pyport.h; several other new header files were added and some old
1975header files were removed, in an attempt to create a more rational set
1976of header files. (Few of these ever need to be included explicitly;
1977they are all included by Python.h.)
1978
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001979Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001980and Win64, especially for the new Intel Itanium processor. Mick also
1981added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001982
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001983The C APIs to return an object's size have been update to consistently
1984use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1985previous versions, the abstract interfaces used PyXXX_Length and the
1986concrete interfaces used PyXXX_Size. The old names,
1987e.g. PyObject_Length, are still available for backwards compatibility
1988at the API level, but are deprecated.
1989
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001990The PyOS_CheckStack function has been implemented on Windows by
1991Fredrik Lundh. It prevents Python from failing with a stack overflow
1992on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001993
1994The GC changes resulted in creation of two new slots on object,
1995tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001996the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001997
1998The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001999C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002000
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002001PyErr_Format has been updated to automatically calculate the size of
2002the buffer needed to hold the formatted result string. This change
2003prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002004
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002005New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002006
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002007PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2008that are the same as their non-Ex counterparts except they take an
2009extra flag argument that tells them to close the file when done.
2010
2011XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002012
Tim Peters8b092332000-09-05 20:15:25 +00002013
2014Windows Changes
2015---------------
2016
2017New popen2/popen3/peopen4 in os module (see Changed Modules above).
2018
2019os.popen is much more usable on Windows 95 and 98. See Microsoft
2020Knowledge Base article Q150956. The Win9x workaround described there
2021is implemented by the new w9xpopen.exe helper in the root of your
2022Python installation. Note that Python uses this internally; it is not
2023a standalone program.
2024
2025Administrator privileges are no longer required to install Python
2026on Windows NT or Windows 2000. If you have administrator privileges,
2027Python's registry info will be written under HKEY_LOCAL_MACHINE.
2028Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002029under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002030uses of Python, but will prevent some advanced uses from working
2031(for example, running a Python script as an NT service, or possibly
2032from CGI).
2033
2034[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2035installer; instead, it installs the needed Tcl/Tk files directly in the
2036Python directory. If you already have a Tcl/Tk installation, this
2037wastes some disk space (about 4 Megs) but avoids problems with
2038conflicting Tcl/Tk installations, and makes it much easier for Python
2039to ensure that Tcl/Tk can find all its files.
2040
2041[This was new in 1.6] The Windows installer now installs by default in
2042\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2043
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002044
2045Updates to the changes between 1.5.2 and 1.6
2046--------------------------------------------
2047
2048The 1.6 NEWS file can't be changed after the release is done, so here
2049is some late-breaking news:
2050
2051New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2052and changes to getlocale() and setlocale().
2053
2054The new module is now enabled per default.
2055
2056It is not true that the encodings codecs cannot be used for normal
2057strings: the string.encode() (which is also present on 8-bit strings
2058!) allows using them for 8-bit strings too, e.g. to convert files from
2059cp1252 (Windows) to latin-1 or vice-versa.
2060
2061Japanese codecs are available from Tamito KAJIYAMA:
2062http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2063
2064
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002065======================================================================