blob: ac32e43bea7aae15c7b824515ed36a3ba7d8d913 [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
Marc-André Lemburg888fac02001-07-31 14:24:31 +000011- Warnings about a mismatch in the Python API during extension import
12 now use the Python warning framework (which makes it possible to
13 write filters for these warnings).
14
15- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
16 which provide a cross-platform implementations for the
17 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
18 the standard sprintf() and vsprintf() C lib APIs, these versions
19 apply bounds checking on the used buffer which enhances protection
20 against buffer overruns.
21
Tim Peters20f51a72001-07-21 02:31:40 +000022Library
23
Fred Drakeb7cea632001-07-21 12:25:10 +000024- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
25 value using the minimal quoting required for the value; more
26 reliable than using xml.sax.saxutils.escape() for attribute values.
27
Martin v. Löwis66b6e192001-07-28 14:44:03 +000028- Readline completion support for cmd.Cmd was added.
29
Tim Peters20f51a72001-07-21 02:31:40 +000030New platforms
31
32C API
33
34
Guido van Rossum55a78992001-07-17 17:22:32 +000035What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +000036===========================
37
38Core
Tim Petersa814db52001-05-14 07:05:58 +000039
Guido van Rossum55a78992001-07-17 17:22:32 +000040- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +000041 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +000042 more 'yield' statements. See PEP 255. Since this adds a new
43 keyword to the language, this feature must be enabled by including a
44 future statement: "from __future__ import generators" (see PEP 236).
45 Generators will become a standard feature in a future release
46 (probably 2.3). Without this future statement, 'yield' remains an
47 ordinary identifier, but a warning is issued each time it is used.
48 (These warnings currently don't conform to the warnings framework of
49 PEP 230; we intend to fix this in 2.2a2.)
50
Marc-André Lemburg12e74b32001-05-22 08:58:23 +000051- The UTF-16 codec was modified to be more RFC compliant. It will now
52 only remove BOM characters at the start of the string and then
53 only if running in native mode (UTF-16-LE and -BE won't remove a
54 leading BMO character).
55
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000056- Strings now have a new method .decode() to complement the already
57 existing .encode() method. These two methods provide direct access
58 to the corresponding decoders and encoders of the registered codecs.
59
60 To enhance the usability of the .encode() method, the special
61 casing of Unicode object return values was dropped (Unicode objects
62 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +000063
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000064 Both methods will now return whatever the codec in charge of the
65 requested encoding returns as object, e.g. Unicode codecs will
66 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
67 will return u"äöü"). This enables codec writer to create codecs
68 for various simple to use conversions.
69
70 New codecs were added to demonstrate these new features (the .encode()
71 and .decode() columns indicate the type of the returned objects):
72
73 Name | .encode() | .decode() | Description
74 ----------------------------------------------------------------------
75 uu | string | string | UU codec (e.g. for email)
76 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +000077 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +000078 zlib | string | string | zlib compression
79 hex | string | string | 2-byte hex codec
80 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
81
Mark Hammond2a0af792001-05-14 03:09:36 +000082- Some operating systems now support the concept of a default Unicode
83 encoding for file system operations. Notably, Windows supports 'mbcs'
84 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +000085 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +000086 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000087
88 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +000089 functions that return filenames (such as os.listdir()) to return Python
90 string objects pre-encoded using the default file system encoding for
91 the platform. As this encoding is likely to be different from Python's
92 default encoding, converting this name to a Unicode object before passing
93 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +000094 would attempt to use its default encoding (generally ASCII) rather than
95 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +000096
Tim Petersa814db52001-05-14 07:05:58 +000097 In general, this change simply removes surprises when working with
98 Unicode and the file system, making these operations work as you expect,
99 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000100 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000101
Tim Peters61dff2b2001-05-08 15:43:37 +0000102- Float (and complex) literals in source code were evaluated to full
103 precision only when running from a .py file; the same code loaded from a
104 .pyc (or .pyo) file could suffer numeric differences starting at about the
105 12th significant decimal digit. For example, on a machine with IEEE-754
106 floating arithmetic,
107
108 x = 9007199254740992.0
109 print long(x)
110
111 printed 9007199254740992 if run directly from .py, but 9007199254740000
112 if from a compiled (.pyc or .pyo) file. This was due to marshal using
113 str(float) instead of repr(float) when building code objects. marshal
114 now uses repr(float) instead, which should reproduce floats to full
115 machine precision (assuming the platform C float<->string I/O conversion
116 functions are of good quality).
117
118 This may cause floating-point results to change in some cases, and
119 usually for the better, but may also cause numerically unstable
120 algorithms to break.
121
Tim Peters2f228e72001-05-13 00:19:31 +0000122- The implementation of dicts suffers fewer collisions, which has speed
123 benefits. However, the order in which dict entries appear in dict.keys(),
124 dict.values() and dict.items() may differ from previous releases for a
125 given dict. Nothing is defined about this order, so no program should
126 rely on it. Nevertheless, it's easy to write test cases that rely on the
127 order by accident, typically because of printing the str() or repr() of a
128 dict to an "expected results" file. See Lib/test/test_support.py's new
129 sortdict(dict) function for a simple way to display a dict in sorted
130 order.
131
Tim Peters7a3bfc32001-06-12 01:22:22 +0000132- Many other small changes to dicts were made, resulting in faster
133 operation along the most common code paths.
134
Guido van Rossum10315822001-05-01 20:54:30 +0000135- Dictionary objects now support the "in" operator: "x in dict" means
136 the same as dict.has_key(x).
137
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000138- The update() method of dictionaries now accepts generic mapping
139 objects. Specifically the argument object must support the .keys()
140 and __getitem__() methods. This allows you to say, for example,
141 {}.update(UserDict())
142
Guido van Rossum10315822001-05-01 20:54:30 +0000143- Iterators were added; this is a generalized way of providing values
144 to a for loop. See PEP 234. There's a new built-in function iter()
145 to return an iterator. There's a new protocol to get the next value
146 from an iterator using the next() method (in Python) or the
147 tp_iternext slot (in C). There's a new protocol to get iterators
148 using the __iter__() method (in Python) or the tp_iter slot (in C).
149 Iterating (i.e. a for loop) over a dictionary generates its keys.
150 Iterating over a file generates its lines.
151
Tim Petersf553f892001-05-01 20:45:31 +0000152- The following functions were generalized to work nicely with iterator
153 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000154 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000155 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
156 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000157 join() method of strings
158 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000159 'x in y' and 'x not in y' (PySequence_Contains() in C API)
160 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000161 right-hand side of assignment statements with multiple targets, such as
162 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000163
Tim Petersd85e1022001-05-11 21:51:48 +0000164- Accessing module attributes is significantly faster (for example,
165 random.random or os.path or yourPythonModule.yourAttribute).
166
Tim Peterse63415e2001-05-08 04:38:29 +0000167- Comparing dictionary objects via == and != is faster, and now works even
168 if the keys and values don't support comparisons other than ==.
169
Tim Peters95bf9392001-05-10 08:32:44 +0000170- Comparing dictionaries in ways other than == and != is slower: there were
171 insecurities in the dict comparison implementation that could cause Python
172 to crash if the element comparison routines for the dict keys and/or
173 values mutated the dicts. Making the code bulletproof slowed it down.
174
Tim Peterseb28ef22001-06-02 05:27:19 +0000175- Collisions in dicts are resolved via a new approach, which can help
176 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000177 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000178 faster now. Thanks to Christian Tismer for pointing out the cause and
179 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000180
Tim Peters52e155e2001-06-16 05:42:57 +0000181- repr() is much faster for large containers (dict, list, tuple).
182
183
Tim Petersa814db52001-05-14 07:05:58 +0000184Library
185
Fred Drake960fdf92001-07-20 18:38:26 +0000186- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
187 were added to the string module. These a locale-indenpendent
188 constants, unlike letters, lowercase, and uppercase. These are now
189 use in appropriate locations in the standard library.
190
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000191- The flags used in dlopen calls can now be configured using
192 sys.setdlopenflags and queried using sys.getdlopenflags.
193
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000194- Fredrik Lundh's xmlrpclib is now a standard library module. This
195 provides full client-side XML-RPC support. In addition,
196 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
197 one asyncore-based). Thanks to Eric Raymond for the documentation.
198
Guido van Rossum643d3912001-07-05 14:46:25 +0000199- The xrange() object is simplified: it no longer supports slicing,
200 repetition, comparisons, efficient 'in' checking, the tolist()
201 method, or the start, stop and step attributes. See PEP 260.
202
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000203- A new function fnmatch.filter to filter lists of file names was added.
204
Barry Warsawffd674d2001-05-22 16:00:10 +0000205- calendar.py uses month and day names based on the current locale.
206
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000207- strop is now *really* obsolete (this was announced before with 1.6),
208 and issues DeprecationWarning when used (except for the four items
209 that are still imported into string.py).
210
Tim Petersa814db52001-05-14 07:05:58 +0000211- Cookie.py now sorts key+value pairs by key in output strings.
212
213- pprint.isrecursive(object) didn't correctly identify recursive objects.
214 Now it does.
215
Tim Peters95b3f782001-05-14 18:39:41 +0000216- pprint functions now much faster for large containers (tuple, list, dict).
217
Tim Peters7b9542a2001-06-10 23:40:19 +0000218- New 'q' and 'Q' format codes in the struct module, corresponding to C
219 types "long long" and "unsigned long long" (on Windows, __int64). In
220 native mode, these can be used only when the platform C compiler supports
221 these types (when HAVE_LONG_LONG is #define'd by the Python config
222 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000223 In standard mode, 'q' and 'Q' are supported on all platforms, and are
224 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000225
Guido van Rossum83213cc2001-06-12 16:48:52 +0000226- The site module installs a new built-in function 'help' that invokes
227 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
228 it displays a message reminding the user to use 'help()' or
229 'help(object)'.
230
Tim Petersa814db52001-05-14 07:05:58 +0000231Tests
232
233- New test_mutants.py runs dict comparisons where the key and value
234 comparison operators mutute the dicts randomly during comparison. This
235 rapidly causes Python to crash under earlier releases (not for the faint
236 of heart: it can also cause Win9x to freeze or reboot!).
237
238- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000239 pprint.isreadable() return sensible results. Also verifies that simple
240 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000241
Tim Peters58e0a8c2001-05-14 22:32:33 +0000242New platforms
243
244- Python should compile and run out of the box using the Borland C
245 compiler (under Windows), thanks to Stephen Hansen.
Tim Petersf553f892001-05-01 20:45:31 +0000246
Tim Peters4324aa32001-05-28 22:30:08 +0000247C API
248
249- Removed the unused last_is_sticky argument from the internal
250 _PyTuple_Resize(). If this affects you, you were cheating.
251
252
Guido van Rossum55a78992001-07-17 17:22:32 +0000253======================================================================
254
255
Guido van Rossumffe13be2001-04-16 18:46:45 +0000256What's New in Python 2.1 (final)?
257=================================
258
259We only changed a few things since the last release candidate, all in
260Python library code:
261
262- A bug in the locale module was fixed that affected locales which
263 define no grouping for numeric formatting.
264
265- A few bugs in the weakref module's implementations of weak
266 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
267 and the test suite was updated to check for these bugs.
268
269- An old bug in the os.path.walk() function (introduced in Python
270 2.0!) was fixed: a non-existent file would cause an exception
271 instead of being ignored.
272
273- Fixed a few bugs in the new symtable module found by Neil Norwitz's
274 PyChecker.
275
276
Guido van Rossum5b08f132001-04-16 02:05:23 +0000277What's New in Python 2.1c2?
278===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000279
Guido van Rossum5b08f132001-04-16 02:05:23 +0000280A flurry of small changes, and one showstopper fixed in the nick of
281time made it necessary to release another release candidate. The list
282here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000283
Guido van Rossum5b08f132001-04-16 02:05:23 +0000284Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000285
Guido van Rossum5b08f132001-04-16 02:05:23 +0000286- Tim discovered a nasty bug in the dictionary code, caused by
287 PyDict_Next() calling dict_resize(), and the GC code's use of
288 PyDict_Next() violating an assumption in dict_items(). This was
289 fixed with considerable amounts of band-aid, but the net effect is a
290 saner and more robust implementation.
291
292- Made a bunch of symbols static that were accidentally global.
293
294Build and Ports
295
296- The setup.py script didn't check for a new enough version of zlib
297 (1.1.3 is needed). Now it does.
298
299- Changed "make clean" target to also remove shared libraries.
300
301- Added a more general warning about the SGI Irix optimizer to README.
302
303Library
304
305- Fix a bug in urllib.basejoin("http://host", "../file.html") which
306 omitted the slash between host and file.html.
307
308- The mailbox module's _Mailbox class contained a completely broken
309 and undocumented seek() method. Ripped it out.
310
311- Fixed a bunch of typos in various library modules (urllib2, smtpd,
312 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
313
314- Fixed a few last-minute bugs in unittest.
315
316Extensions
317
318- Reverted the patch to the OpenSSL code in socketmodule.c to support
319 RAND_status() and the EGD, and the subsequent patch that tried to
320 fix it for pre-0.9.5 versions; the problem with the patch is that on
321 some systems it issues a warning whenever socket is imported, and
322 that's unacceptable.
323
324Tests
325
326- Fixed the pickle tests to work with "import test.test_pickle".
327
328- Tweaked test_locale.py to actually run the test Windows.
329
330- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
331 not "wb" (which is not a valid mode at all).
332
333- Fix pstats browser crashes. Import readline if it exists to make
334 the user interface nicer.
335
336- Add "import thread" to the top of test modules that import the
337 threading module (test_asynchat and test_threadedtempfile). This
338 prevents test failures caused by a broken threading module resulting
339 from a previously caught failed import.
340
341- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
342 needed on some platforms (e.g. Solaris 8) when the tests are run
343 twice in succession.
344
345- Skip rather than fail test_sunaudiodev if no audio device is found.
346
347
348What's New in Python 2.1c1?
349===========================
350
351This list was significantly updated when 2.1c2 was released; the 2.1c1
352release didn't mention most changes that were actually part of 2.1c1:
353
354Legal
355
356- Copyright was assigned to the Python Software Foundation (PSF) and a
357 PSF license (very similar to the CNRI license) was added.
358
359- The CNRI copyright notice was updated to include 2001.
360
361Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000362
Guido van Rossumc9932722001-04-12 02:31:27 +0000363- After a public outcry, assignment to __debug__ is no longer illegal;
364 instead, a warning is issued. It will become illegal in 2.2.
365
Guido van Rossum5b08f132001-04-16 02:05:23 +0000366- Fixed a core dump with "%#x" % 0, and changed the semantics so that
367 "%#x" now always prepends "0x", even if the value is zero.
368
369- Fixed some nits in the bytecode compiler.
370
371- Fixed core dumps when calling certain kinds of non-functions.
372
373- Fixed various core dumps caused by reference count bugs.
374
375Build and Ports
376
377- Use INSTALL_SCRIPT to install script files.
378
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000379- New port: SCO Unixware 7, by Billy G. Allie.
380
Guido van Rossum5b08f132001-04-16 02:05:23 +0000381- Updated RISCOS port.
382
383- Updated BeOS port and notes.
384
385- Various other porting problems resolved.
386
387Library
388
389- The TERMIOS and SOCKET modules are now truly obsolete and
390 unnecessary. Their symbols are incorporated in the termios and
391 socket modules.
392
393- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
394 better tests for pickling.
395
396- threading: make Condition.wait() robust against KeyboardInterrupt.
397
398- zipfile: add support to zipfile to support opening an archive
399 represented by an open file rather than a file name. Fix bug where
400 the archive was not properly closed. Fixed a bug in this bugfix
401 where flush() was called for a read-only file.
402
403- imputil: added an uninstall() method to the ImportManager.
404
405- Canvas: fixed bugs in lower() and tkraise() methods.
406
407- SocketServer: API change (added overridable close_request() method)
408 so that the TCP server can explicitly close the request.
409
410- pstats: Eric Raymond added a simple interactive statistics browser,
411 invoked when the module is run as a script.
412
413- locale: fixed a problem in format().
414
415- webbrowser: made it work when the BROWSER environment variable has a
416 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
417 KDE 2. Fixed some other nits.
418
419- unittest: changes to allow using a different exception than
420 AssertionError, and added a few more function aliases. Some other
421 small changes.
422
423- urllib, urllib2: fixed redirect problems and a coupleof other nits.
424
425- asynchat: fixed a critical bug in asynchat that slipped through the
426 2.1b2 release. Fixed another rare bug.
427
428- Fix some unqualified except: clauses (always a bad code example).
429
430XML
431
432- pyexpat: new API get_version_string().
433
434- Fixed some minidom bugs.
435
436Extensions
437
438- Fixed a core dump in _weakref. Removed the weakref.mapping()
439 function (it adds nothing to the API).
440
441- Rationalized the use of header files in the readline module, to make
442 it compile (albeit with some warnings) with the very recent readline
443 4.2, without breaking for earlier versions.
444
445- Hopefully fixed a buffering problem in linuxaudiodev.
446
447- Attempted a fix to make the OpenSSL support in the socket module
448 work again with pre-0.9.5 versions of OpenSSL.
449
450Tests
451
452- Added a test case for asynchat and asyncore.
453
454- Removed coupling between tests where one test failing could break
455 another.
456
457Tools
458
459- Ping added an interactive help browser to pydoc, fixed some nits
460 in the rest of the pydoc code, and added some features to his
461 inspect module.
462
463- An updated python-mode.el version 4.1 which integrates Ken
464 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
465 much nicer in XEmacs and Emacs. When stepping through your program
466 with pdb, in either the shell window or the *Python* window, the
467 source file and line will be tracked by an arrow. Very cool!
468
469- IDLE: syntax warnings in interactive mode are changed into errors.
470
471- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000472 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000473
474- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000475
Barry Warsaw11e89c72001-04-11 20:37:57 +0000476
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000477What's New in Python 2.1 beta 2?
478================================
479
Guido van Rossum053ae352001-03-22 14:17:21 +0000480(Unlisted are many fixed bugs, more documentation, etc.)
481
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000482Core language, builtins, and interpreter
483
Guido van Rossum053ae352001-03-22 14:17:21 +0000484- The nested scopes work (enabled by "from __future__ import
485 nested_scopes") is completed; in particular, the future now extends
486 into code executed through exec, eval() and execfile(), and into the
487 interactive interpreter.
488
489- When calling a base class method (e.g. BaseClass.__init__(self)),
490 this is now allowed even if self is not strictly spoken a class
491 instance (e.g. when using metaclasses or the Don Beaudry hook).
492
493- Slice objects are now comparable but not hashable; this prevents
494 dict[:] from being accepted but meaningless.
495
496- Complex division is now calculated using less braindead algorithms.
497 This doesn't change semantics except it's more likely to give useful
498 results in extreme cases. Complex repr() now uses full precision
499 like float repr().
500
501- sgmllib.py now calls handle_decl() for simple <!...> declarations.
502
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000503- It is illegal to assign to the name __debug__, which is set when the
504 interpreter starts. It is effectively a compile-time constant.
505
506- A warning will be issued if a global statement for a variable
507 follows a use or assignment of that variable.
508
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000509Standard library
510
Guido van Rossum053ae352001-03-22 14:17:21 +0000511- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
512 inspired by JUnit), is now part of the standard library. You now
513 have a choice of two testing frameworks: unittest requires you to
514 write testcases as separate code, doctest gathers them from
515 docstrings. Both approaches have their advantages and
516 disadvantages.
517
518- A new module Tix was added, which wraps the Tix extension library
519 for Tk. With that module, it is not necessary to statically link
520 Tix with _tkinter, since Tix will be loaded with Tcl's "package
521 require" command. See Demo/tix/.
522
523- tzparse.py is now obsolete.
524
525- In gzip.py, the seek() and tell() methods are removed -- they were
526 non-functional anyway, and it's better if callers can test for their
527 existence with hasattr().
528
529Python/C API
530
531- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
532 that's already in the dictionary during a PyDict_Next() iteration.
533 This used to fail occasionally when a dictionary resize operation
534 could be triggered that would rehash all the keys. All other
535 modifications to the dictionary are still off-limits during a
536 PyDict_Next() iteration!
537
538- New extended APIs related to passing compiler variables around.
539
540- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
541 implement isinstance() and issubclass().
542
543- Py_BuildValue() now has a "D" conversion to create a Python complex
544 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000545
Fred Drake4e262a92001-03-22 18:26:47 +0000546- Extensions types which support weak references must now set the
547 field allocated for the weak reference machinery to NULL themselves;
548 this is done to avoid the cost of checking each object for having a
549 weakly referencable type in PyObject_INIT(), since most types are
550 not weakly referencable.
551
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000552- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
553 free variables and cell variables to and from the frame's f_locals.
554
555- Variants of several functions defined in pythonrun.h have been added
556 to support the nested_scopes future statement. The variants all end
557 in Flags and take an extra argument, a PyCompilerFlags *; examples:
558 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
559 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000560 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000561
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000562Distutils
563
564- the sdist command now writes a PKG-INFO file, as described in PEP 241,
565 into the release tree.
566
Tim Peters0e57abf2001-05-02 07:39:38 +0000567- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000568 (an uninstaller, more customization of the installer's display)
569
570- from Jack Jansen: added Mac-specific code to generate a dialog for
571 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000572 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000573 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000574
575- added 'platforms' and 'keywords' to the set of metadata that can be
576 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000577
578- applied patches from Jason Tishler to make the compiler class work with
579 Cygwin.
580
581
Tim Peters2fe289a2001-03-01 22:19:38 +0000582What's New in Python 2.1 beta 1?
583================================
Tim Petersd66595f2001-02-04 03:09:53 +0000584
585Core language, builtins, and interpreter
586
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000587- Following an outcry from the community about the amount of code
588 broken by the nested scopes feature introduced in 2.1a2, we decided
589 to make this feature optional, and to wait until Python 2.2 (or at
590 least 6 months) to make it standard. The option can be enabled on a
591 per-module basis by adding "from __future__ import nested_scopes" at
592 the beginning of a module (before any other statements, but after
593 comments and an optional docstring). See PEP 236 (Back to the
594 __future__) for a description of the __future__ statement. PEP 227
595 (Statically Nested Scopes) has been updated to reflect this change,
596 and to clarify the semantics in a number of endcases.
597
598- The nested scopes code, when enabled, has been hardened, and most
599 bugs and memory leaks in it have been fixed.
600
601- Compile-time warnings are now generated for a number of conditions
602 that will break or change in meaning when nested scopes are enabled:
603
604 - Using "from...import *" or "exec" without in-clause in a function
605 scope that also defines a lambda or nested function with one or
606 more free (non-local) variables. The presence of the import* or
607 bare exec makes it impossible for the compiler to determine the
608 exact set of local variables in the outer scope, which makes it
609 impossible to determine the bindings for free variables in the
610 inner scope. To avoid the warning about import *, change it into
611 an import of explicitly name object, or move the import* statement
612 to the global scope; to avoid the warning about bare exec, use
613 exec...in... (a good idea anyway -- there's a possibility that
614 bare exec will be deprecated in the future).
615
616 - Use of a global variable in a nested scope with the same name as a
617 local variable in a surrounding scope. This will change in
618 meaning with nested scopes: the name in the inner scope will
619 reference the variable in the outer scope rather than the global
620 of the same name. To avoid the warning, either rename the outer
621 variable, or use a global statement in the inner function.
622
Neil Schemenauera35c6882001-02-27 04:45:05 +0000623- An optional object allocator has been included. This allocator is
624 optimized for Python objects and should be faster and use less memory
625 than the standard system allocator. It is not enabled by default
626 because of possible thread safety problems. The allocator is only
627 protected by the Python interpreter lock and it is possible that some
628 extension modules require a thread safe allocator. The object
629 allocator can be enabled by providing the "--with-pymalloc" option to
630 configure.
631
Tim Petersd66595f2001-02-04 03:09:53 +0000632Standard library
633
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000634- pyexpat now detects the expat version if expat.h defines it. A
635 number of additional handlers are provided, which are only available
636 since expat 1.95. In addition, the methods SetParamEntityParsing and
637 GetInputContext of Parser objects are available with 1.95.x
638 only. Parser objects now provide the ordered_attributes and
639 specified_attributes attributes. A new module expat.model was added,
640 which offers a number of additional constants if 1.95.x is used.
641
642- xml.dom offers the new functions registerDOMImplementation and
643 getDOMImplementation.
644
645- xml.dom.minidom offers a toprettyxml method. A number of DOM
646 conformance issues have been resolved. In particular, Element now
647 has an hasAttributes method, and the handling of namespaces was
648 improved.
649
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000650- Ka-Ping Yee contributed two new modules: inspect.py, a module for
651 getting information about live Python code, and pydoc.py, a module
652 for interactively converting docstrings to HTML or text.
653 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000654 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000655 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
656 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000657
Tim Peters1eff7962001-03-01 02:31:33 +0000658- New library module difflib.py, primarily packaging the SequenceMatcher
659 class at the heart of the popular ndiff.py file-comparison tool.
660
661- doctest.py (a framework for verifying Python code examples in docstrings)
662 is now part of the std library.
663
Tim Petersd66595f2001-02-04 03:09:53 +0000664Windows changes
665
Guido van Rossume3955a82001-03-02 14:05:59 +0000666- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
667 small GUI that lets you browse the module docstrings using your
668 default web browser.
669
Tim Peters1eff7962001-03-01 02:31:33 +0000670- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
671 Platforms) is implemented. See
672
673 http://python.sourceforge.net/peps/pep-0235.html
674
675 for full details, especially the "Current Lower-Left Semantics" section.
676 The new Windows import rules are simpler than before:
677
678 A. If the PYTHONCASEOK environment variable exists, same as
679 before: silently accept the first case-insensitive match of any
680 kind; raise ImportError if none found.
681
682 B. Else search sys.path for the first case-sensitive match; raise
683 ImportError if none found.
684
685 The same rules have been implented on other platforms with case-
686 insensitive but case-preserving filesystems too (including Cygwin, and
687 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000688
Tim Peters25a9ce32001-02-19 07:06:36 +0000689- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
690 what it's supposed to do (and does do under NT and 2000) via direct
691 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000692 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000693 all Win9x systems before.
694
Tim Peters1eff7962001-03-01 02:31:33 +0000695- Build: Subproject _test (effectively) renamed to _testcapi.
696
Tim Peters2fe289a2001-03-01 22:19:38 +0000697New platforms
698
699- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
700 Thanks to Steven Majewski!
701
702- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
703 Tishler!
704
Guido van Rossum9089b272001-03-02 06:49:50 +0000705- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
706 Schwertberger! See RISCOS/README for more information -- it seems
707 that because of the bizarre filename conventions on RISCOS, no port
708 to that platform is easy. Note that the new variable os.endsep is
709 silently supported in order to make life easier on this platform,
710 but we don't advertise it because it's not worth for most folks to
711 care about RISCOS portability.
712
Tim Peters25a9ce32001-02-19 07:06:36 +0000713
Tim Petersd7b5e882001-01-25 03:36:26 +0000714What's New in Python 2.1 alpha 2?
715=================================
Tim Peters40ead762001-01-27 05:35:26 +0000716
Tim Petersd7b5e882001-01-25 03:36:26 +0000717Core language, builtins, and interpreter
718
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000719- Scopes nest. If a name is used in a function or class, but is not
720 local, the definition in the nearest enclosing function scope will
721 be used. One consequence of this change is that lambda statements
722 could reference variables in the namespaces where the lambda is
723 defined. In some unusual cases, this change will break code.
724
725 In all previous version of Python, names were resolved in exactly
726 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000727 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000728 function A is defined within a function B, the names bound in B are
729 not visible in A. The new rules make names bound in B visible in A,
730 unless A contains a name binding that hides the binding in B.
731
732 Section 4.1 of the reference manual describes the new scoping rules
733 in detail. The test script in Lib/test/test_scope.py demonstrates
734 some of the effects of the change.
735
736 The new rules will cause existing code to break if it defines nested
737 functions where an outer function has local variables with the same
738 name as globals or builtins used by the inner function. Example:
739
740 def munge(str):
741 def helper(x):
742 return str(x)
743 if type(str) != type(''):
744 str = helper(str)
745 return str.strip()
746
747 Under the old rules, the name str in helper() is bound to the
748 builtin function str(). Under the new rules, it will be bound to
749 the argument named str and an error will occur when helper() is
750 called.
751
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000752- The compiler will report a SyntaxError if "from ... import *" occurs
753 in a function or class scope. The language reference has documented
754 that this case is illegal, but the compiler never checked for it.
755 The recent introduction of nested scope makes the meaning of this
756 form of name binding ambiguous. In a future release, the compiler
757 may allow this form when there is no possibility of ambiguity.
758
Tim Peters40ead762001-01-27 05:35:26 +0000759- repr(string) is easier to read, now using hex escapes instead of octal,
760 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
761
762 >>> "\texample \r\n" + chr(0) + chr(255)
763 '\texample \r\n\x00\xff' # in 2.1
764 '\011example \015\012\000\377' # in 2.0
765
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000766- Functions are now compared and hashed by identity, not by value, since
767 the func_code attribute is writable.
768
Fred Drakefb9d7122001-02-01 20:00:40 +0000769- Weak references (PEP 205) have been added. This involves a few
770 changes in the core, an extension module (_weakref), and a Python
771 module (weakref). The weakref module is the public interface. It
772 includes support for "explicit" weak references, proxy objects, and
773 mappings with weakly held values.
774
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000775- A 'continue' statement can now appear in a try block within the body
776 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000777 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000778
Tim Petersd7b5e882001-01-25 03:36:26 +0000779Standard library
780
Barry Warsaw30dbd142001-01-31 22:14:01 +0000781- mailbox.py now has a new class, PortableUnixMailbox which is
782 identical to UnixMailbox but uses a more portable scheme for
783 determining From_ separators. Also, the constructors for all the
784 classes in this module have a new optional `factory' argument, which
785 is a callable used when new message classes must be instantiated by
786 the next() method.
787
Tim Petersd7b5e882001-01-25 03:36:26 +0000788- random.py is now self-contained, and offers all the functionality of
789 the now-deprecated whrandom.py. See the docs for details. random.py
790 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000791 and restoring the internal state of the generator; and jumpahead(n),
792 for quickly forcing the internal state to be the same as if n calls to
793 random() had been made. The latter is particularly useful for multi-
794 threaded programs, creating one instance of the random.Random() class for
795 each thread, then using .jumpahead() to force each instance to use a
796 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000797
Tim Peters0de88fc2001-02-01 04:59:18 +0000798- random.py's seed() function is new. For bit-for-bit compatibility with
799 prior releases, use the whseed function instead. The new seed function
800 addresses two problems: (1) The old function couldn't produce more than
801 about 2**24 distinct internal states; the new one about 2**45 (the best
802 that can be done in the Wichmann-Hill generator). (2) The old function
803 sometimes produced identical internal states when passed distinct
804 integers, and there was no simple way to predict when that would happen;
805 the new one guarantees to produce distinct internal states for all
806 arguments in [0, 27814431486576L).
807
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000808- The socket module now supports raw packets on Linux. The socket
809 family is AF_PACKET.
810
Tim Peters9ea17ac2001-02-02 05:57:15 +0000811- test_capi.py is a start at running tests of the Python C API. The tests
812 are implemented by the new Modules/_testmodule.c.
813
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000814- A new extension module, _symtable, provides provisional access to the
815 internal symbol table used by the Python compiler. A higher-level
816 interface will be added on top of _symtable in a future release.
817
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000818- Removed the obsolete soundex module.
819
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000820- xml.dom.minidom now uses the standard DOM exceptions. Node supports
821 the isSameNode method; NamedNodeMap the get method.
822
823- xml.sax.expatreader supports the lexical handler property; it
824 generates comment, startCDATA, and endCDATA events.
825
Tim Petersee826f82001-01-31 19:39:44 +0000826Windows changes
827
828- Build procedure: the zlib project is built in a different way that
829 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000830 the zlib binary used. See PCbuild\readme.txt for details. Your old
831 zlib-related directories can be deleted; you'll need to download fresh
832 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000833
Tim Peters9ea17ac2001-02-02 05:57:15 +0000834- Build: New subproject _test for the benefit of test_capi.py (see above).
835
Tim Petersb16c56f2001-02-02 21:24:51 +0000836- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
837 interface to some Python compiler internals).
838
839- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000840 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000841
Tim Petersa3a3a032000-11-30 05:22:44 +0000842What's New in Python 2.1 alpha 1?
843=================================
844
845Core language, builtins, and interpreter
846
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000847- There is a new Unicode companion to the PyObject_Str() API
848 called PyObject_Unicode(). It behaves in the same way as the
849 former, but assures that the returned value is an Unicode object
850 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000851
Guido van Rossumf98eda02001-01-17 15:54:45 +0000852- The comparison operators support "rich comparison overloading" (PEP
853 207). C extension types can provide a rich comparison function in
854 the new tp_richcompare slot in the type object. The cmp() function
855 and the C function PyObject_Compare() first try the new rich
856 comparison operators before trying the old 3-way comparison. There
857 is also a new C API PyObject_RichCompare() (which also falls back on
858 the old 3-way comparison, but does not constrain the outcome of the
859 rich comparison to a Boolean result).
860
861 The rich comparison function takes two objects (at least one of
862 which is guaranteed to have the type that provided the function) and
863 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
864 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
865 object, which may be NotImplemented (in which case the tp_compare
866 slot function is used as a fallback, if defined).
867
868 Classes can overload individual comparison operators by defining one
869 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000870 __ge__. There are no explicit "reflected argument" versions of
871 these; instead, __lt__ and __gt__ are each other's reflection,
872 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
873 reflection (similar at the C level). No other implications are
874 made; in particular, Python does not assume that == is the Boolean
875 inverse of !=, or that < is the Boolean inverse of >=. This makes
876 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000877
878 Classes or types that want to implement (in)equality tests but not
879 the ordering operators (i.e. unordered types) should implement ==
880 and !=, and raise an error for the ordering operators.
881
Guido van Rossuma88479f2001-01-18 14:28:08 +0000882 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000883 Boolean; e.g. a matrix type might want to return a matrix of bits
884 for A < B, giving elementwise comparisons. Such types should ensure
885 that any interpretation of their value in a Boolean context raises
886 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
887 at the C level) to always raise an exception.
888
Guido van Rossuma88479f2001-01-18 14:28:08 +0000889- Complex numbers use rich comparisons to define == and != but raise
890 an exception for <, <=, > and >=. Unfortunately, this also means
891 that cmp() of two complex numbers raises an exception when the two
892 numbers differ. Since it is not mathematically meaningful to compare
893 complex numbers except for equality, I hope that this doesn't break
894 too much code.
895
Tim Peters3389f192001-02-18 08:48:49 +0000896- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000897 not defined by the language, other than that it's arbitrary but
898 consistent (see the Reference Manual). An implementation detail changed
899 in 2.1a1 such that None now compares less than any other object. Code
900 relying on this new behavior (like code that relied on the previous
901 behavior) does so at its own risk.
902
Barry Warsaw573b5412001-01-15 20:43:18 +0000903- Functions and methods now support getting and setting arbitrarily
904 named attributes (PEP 232). Functions have a new __dict__
905 (a.k.a. func_dict) which hold the function attributes. Methods get
906 and set attributes on their underlying im_func. It is a TypeError
907 to set an attribute on a bound method.
908
Guido van Rossum051e3352001-01-15 19:11:10 +0000909- The xrange() object implementation has been improved so that
910 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
911 limitation that in this case len(xrange(sys.maxint)) can't be
912 calculated, but the common idiom "for i in xrange(sys.maxint)" will
913 work fine as long as the index i doesn't actually reach 2**31.
914 (Python uses regular ints for sequence and string indices; fixing
915 that is much more work.)
916
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000917- Two changes to from...import:
918
Guido van Rossumba381232001-02-03 15:06:40 +0000919 1) "from M import X" now works even if (after loading module M)
920 sys.modules['M'] is not a real module; it's basically a getattr()
921 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000922
923 2) "from M import *" now looks for M.__all__ to decide which names to
924 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
925 filters out names starting with '_' as before. Whether or not
926 __all__ exists, there's no restriction on the type of M.
927
Guido van Rossumf61f1662001-01-10 20:13:55 +0000928- File objects have a new method, xreadlines(). This is the fastest
929 way to iterate over all lines in a file:
930
931 for line in file.xreadlines():
932 ...do something to line...
933
934 See the xreadlines module (mentioned below) for how to do this for
935 other file-like objects.
936
937- Even if you don't use file.xreadlines(), you may expect a speedup on
938 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000939 quite a bit in platform-specific ways: on systems (like Linux) that
940 support flockfile(), getc_unlocked(), and funlockfile(), those are
941 used by default. On systems (like Windows) without getc_unlocked(),
942 a complicated (but still thread-safe) method using fgets() is used by
943 default.
944
Tim Petersd52269b2001-01-25 06:23:18 +0000945 You can force use of the fgets() method by #define'ing
946 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000947 getc_unlocked()).
948
Tim Petersd52269b2001-01-25 06:23:18 +0000949 You can force fgets() not to be used by #define'ing
950 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000951 test_bufio.py fails -- and let us know if it does!).
952
953- In addition, the fileinput module, while still slower than the other
954 methods on most platforms, has been sped up too, by using
955 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000956
957- Support for run-time warnings has been added, including a new
958 command line option (-W) to specify the disposition of warnings.
959 See the description of the warnings module below.
960
961- Extensive changes have been made to the coercion code. This mostly
962 affects extension modules (which can now implement mixed-type
963 numerical operators without having to use coercion), but
964 occasionally, in boundary cases the coercion semantics have changed
965 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000966 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000967 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000968 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000969
Guido van Rossumf98eda02001-01-17 15:54:45 +0000970- In connection with the coercion changes, a new built-in singleton
971 object, NotImplemented is defined. This can be returned for
972 operations that wish to indicate they are not implemented for a
973 particular combination of arguments. From C, this is
974 Py_NotImplemented.
975
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000976- The interpreter accepts now bytecode files on the command line even
977 if they do not have a .pyc or .pyo extension. On Linux, after executing
978
Martin v. Löwise214baa2001-02-04 22:37:56 +0000979import imp,sys,string
980magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
981reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
982open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000983
984 any byte code file can be used as an executable (i.e. as an argument
985 to execve(2)).
986
Tim Peters9940b802000-12-01 07:59:35 +0000987- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000988 character. In 1.6 and earlier, they never produced a sign,
989 and raised an error if the value of the long was too large
990 to fit in a Python int. In 2.0, they produced a sign if and
991 only if too large to fit in an int. This was inconsistent
992 across platforms (because the size of an int varies across
993 platforms), and inconsistent with hex() and oct(). Example:
994
995 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000996 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000997 'ffffffbe' # in 2.0 and before, on 32-bit machines
998 >>> hex(-0x42L)
999 '-0x42L' # in all versions of Python
1000
Tim Peters9940b802000-12-01 07:59:35 +00001001 The behavior of %d formats for negative Python longs remains
1002 the same as in 2.0 (although in 1.6 and before, they raised
1003 an error if the long didn't fit in a Python int).
1004
1005 %u formats don't make sense for Python longs, but are allowed
1006 and treated the same as %d in 2.1. In 2.0, a negative long
1007 formatted via %u produced a sign if and only if too large to
1008 fit in an int. In 1.6 and earlier, a negative long formatted
1009 via %u raised an error if it was too big to fit in an int.
1010
Guido van Rossum3661d392000-12-12 22:10:31 +00001011- Dictionary objects have an odd new method, popitem(). This removes
1012 an arbitrary item from the dictionary and returns it (in the form of
1013 a (key, value) pair). This can be useful for algorithms that use a
1014 dictionary as a bag of "to do" items and repeatedly need to pick one
1015 item. Such algorithms normally end up running in quadratic time;
1016 using popitem() they can usually be made to run in linear time.
1017
Tim Peters36cdad12000-12-29 02:06:45 +00001018Standard library
1019
Thomas Woutersfe385252001-01-19 23:16:56 +00001020- In the time module, the time argument to the functions strftime,
1021 localtime, gmtime, asctime and ctime is now optional, defaulting to
1022 the current time (in the local timezone).
1023
Guido van Rossumda91f222001-01-15 16:36:08 +00001024- The ftplib module now defaults to passive mode, which is deemed a
1025 more useful default given that clients are often inside firewalls
1026 these days. Note that this could break if ftplib is used to connect
1027 to a *server* that is inside a firewall, from outside; this is
1028 expected to be a very rare situation. To fix that, you can call
1029 ftp.set_pasv(0).
1030
Martin v. Löwis10a27872001-01-13 09:54:41 +00001031- The module site now treats .pth files not only for path configuration,
1032 but also supports extensions to the initialization code: Lines starting
1033 with import are executed.
1034
Guido van Rossumf61f1662001-01-10 20:13:55 +00001035- There's a new module, warnings, which implements a mechanism for
1036 issuing and filtering warnings. There are some new built-in
1037 exceptions that serve as warning categories, and a new command line
1038 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1039 turns warnings into errors). warnings.warn(message[, category])
1040 issues a warning message; this can also be called from C as
1041 PyErr_Warn(category, message).
1042
1043- A new module xreadlines was added. This exports a single factory
1044 function, xreadlines(). The intention is that this code is the
1045 absolutely fastest way to iterate over all lines in an open
1046 file(-like) object:
1047
1048 import xreadlines
1049 for line in xreadlines.xreadlines(file):
1050 ...do something to line...
1051
1052 This is equivalent to the previous the speed record holder using
1053 file.readlines(sizehint). Note that if file is a real file object
1054 (as opposed to a file-like object), this is equivalent:
1055
1056 for line in file.xreadlines():
1057 ...do something to line...
1058
Tim Peters36cdad12000-12-29 02:06:45 +00001059- The bisect module has new functions bisect_left, insort_left,
1060 bisect_right and insort_right. The old names bisect and insort
1061 are now aliases for bisect_right and insort_right. XXX_right
1062 and XXX_left methods differ in what happens when the new element
1063 compares equal to one or more elements already in the list: the
1064 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001065 right. Code that doesn't care where equal elements end up should
1066 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001067
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001068- The new curses.panel module wraps the panel library that forms part
1069 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1070
Guido van Rossumf61f1662001-01-10 20:13:55 +00001071- The SocketServer module now sets the allow_reuse_address flag by
1072 default in the TCPServer class.
1073
1074- A new function, sys._getframe(), returns the stack frame pointer of
1075 the caller. This is intended only as a building block for
1076 higher-level mechanisms such as string interpolation.
1077
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001078- The pyexpat module supports a number of new handlers, which are
1079 available only in expat 1.2. If invocation of a callback fails, it
1080 will report an additional frame in the traceback. Parser objects
1081 participate now in garbage collection. If expat reports an unknown
1082 encoding, pyexpat will try to use a Python codec; that works only
1083 for single-byte charsets. The parser type objects is exposed as
1084 XMLParserObject.
1085
1086- xml.dom now offers standard definitions for symbolic node type and
1087 exception code constants, and a hierarchy of DOM exceptions. minidom
1088 was adjusted to use them.
1089
1090- The conformance of xml.dom.minidom to the DOM specification was
1091 improved. It detects a number of additional error cases; the
1092 previous/next relationship works even when the tree is modified;
1093 Node supports the normalize() method; NamedNodeMap, DocumentType and
1094 DOMImplementation classes were added; Element supports the
1095 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1096 method.
1097
Guido van Rossumf61f1662001-01-10 20:13:55 +00001098Build issues
1099
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001100- For Unix (and Unix-compatible) builds, configuration and building of
1101 extension modules is now greatly automated. Rather than having to
1102 edit the Modules/Setup file to indicate which modules should be
1103 built and where their include files and libraries are, a
1104 distutils-based setup.py script now takes care of building most
1105 extension modules. All extension modules built this way are built
1106 as shared libraries. Only a few modules that must be linked
1107 statically are still listed in the Setup file; you won't need to
1108 edit their configuration.
1109
1110- Python should now build out of the box on Cygwin. If it doesn't,
1111 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001112
1113- Python now always uses its own (renamed) implementation of getopt()
1114 -- there's too much variation among C library getopt()
1115 implementations.
1116
1117- C++ compilers are better supported; the CXX macro is always set to a
1118 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001119
Tim Petersd92dfe02000-12-12 01:18:41 +00001120Windows changes
1121
1122- select module: By default under Windows, a select() call
1123 can specify no more than 64 sockets. Python now boosts
1124 this Microsoft default to 512. If you need even more than
1125 that, see the MS docs (you'll need to #define FD_SETSIZE
1126 and recompile Python from source).
1127
Guido van Rossumf61f1662001-01-10 20:13:55 +00001128- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1129 subdirectory is no more!
1130
Tim Petersa3a3a032000-11-30 05:22:44 +00001131
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001132What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001133=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001134
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001135Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001136changes are in the file HISTORY. If you are making the jump directly
1137from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1138HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001139
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001140Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1141the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1142http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001143
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001144--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001145
1146======================================================================
1147
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001148What's new in 2.0 (since release candidate 1)?
1149==============================================
1150
1151Standard library
1152
1153- The copy_reg module was modified to clarify its intended use: to
1154 register pickle support for extension types, not for classes.
1155 pickle() will raise a TypeError if it is passed a class.
1156
1157- Fixed a bug in gettext's "normalize and expand" code that prevented
1158 it from finding an existing .mo file.
1159
1160- Restored support for HTTP/0.9 servers in httplib.
1161
Tim Peters989b7b92000-10-16 20:24:53 +00001162- The math module was changed to stop raising OverflowError in case of
1163 underflow, and return 0 instead in underflow cases. Whether Python
1164 used to raise OverflowError in case of underflow was platform-
1165 dependent (it did when the platform math library set errno to ERANGE
1166 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001167
1168- Fixed a bug in StringIO that occurred when the file position was not
1169 at the end of the file and write() was called with enough data to
1170 extend past the end of the file.
1171
1172- Fixed a bug that caused Tkinter error messages to get lost on
1173 Windows. The bug was fixed by replacing direct use of
1174 interp->result with Tcl_GetStringResult(interp).
1175
1176- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1177 redirect response.
1178
1179- Several changes were made to distutils: Some debugging code was
1180 removed from util. Fixed the installer used when an external zip
1181 program (like WinZip) is not found; the source code for this
1182 installer is in Misc/distutils. check_lib() was modified to behave
1183 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1184 test for whether installed modules are on sys.path was changed to
1185 use both normcase() and normpath().
1186
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001187- Several minor bugs were fixed in the xml package (the minidom,
1188 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001189
1190- The regression test driver (regrtest.py) behavior when invoked with
1191 -l changed: It now reports a count of objects that are recognized as
1192 garbage but not freed by the garbage collector.
1193
Tim Peters989b7b92000-10-16 20:24:53 +00001194- The regression test for the math module was changed to test
1195 exceptional behavior when the test is run in verbose mode. Python
1196 cannot yet guarantee consistent exception behavior across platforms,
1197 so the exception part of test_math is run only in verbose mode, and
1198 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001199
1200Internals
1201
1202- PyOS_CheckStack() has been disabled on Win64, where it caused
1203 test_sre to fail.
1204
1205Build issues
1206
1207- Changed compiler flags, so that gcc is always invoked with -Wall and
1208 -Wstrict-prototypes. Users compiling Python with GCC should see
1209 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001210 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001211 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001212
Tim Petersa3a3a032000-11-30 05:22:44 +00001213- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001214
1215Tools and other miscellany
1216
1217- The compiler in Tools/compiler was updated to support the new
1218 language features introduced in 2.0: extended print statement, list
1219 comprehensions, and augmented assignments. The new compiler should
1220 also be backwards compatible with Python 1.5.2; the compiler will
1221 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001222 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001223
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001224What's new in 2.0 release candidate 1 (since beta 2)?
1225=====================================================
1226
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001227What is release candidate 1?
1228
1229We believe that release candidate 1 will fix all known bugs that we
1230intend to fix for the 2.0 final release. This release should be a bit
1231more stable than the previous betas. We would like to see even more
1232widespread testing before the final release, so we are producing this
1233release candidate. The final release will be exactly the same unless
1234any show-stopping (or brown bag) bugs are found by testers of the
1235release candidate.
1236
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001237All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001238to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001239
1240Core language, builtins, and interpreter
1241
1242- A bug that caused crashes when __coerce__ was used with augmented
1243 assignment, e.g. +=, was fixed.
1244
1245- Raise ZeroDivisionError when raising zero to a negative number,
1246 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1247 power operator and the result of math.pow(0.0, -2.0) will vary by
1248 platform. On Linux, it raises a ValueError.
1249
1250- A bug in Unicode string interpolation was fixed that occasionally
1251 caused errors with formats including "%%". For example, the
1252 following expression "%% %s" % u"abc" no longer raises a TypeError.
1253
1254- Compilation of deeply nested expressions raises MemoryError instead
1255 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1256
1257- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1258 rendering them useless. They are now written in binary mode again.
1259
1260Standard library
1261
1262- Keyword arguments are now accepted for most pattern and match object
1263 methods in SRE, the standard regular expression engine.
1264
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001265- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001266 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001267
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001268- Several bugs in the Unicode handling and error handling in _tkinter
1269 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001270
1271- Fix memory management errors in Merge() and Tkapp_Call() routines.
1272
1273- Several changes were made to cStringIO to make it compatible with
1274 the file-like object interface and with StringIO. If operations are
1275 performed on a closed object, an exception is raised. The truncate
1276 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001277 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001278
1279- There were many changes made to the linuxaudiodev module and its
1280 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001281 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001282
1283 Note that this module is named poorly, because it should work
1284 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001285 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001286
1287 The module now raises exceptions when errors occur instead of
1288 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1289 audio) and defines a getptr() method that calls the
1290 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1291
1292- The library_version attribute, introduced in an earlier beta, was
1293 removed because it can not be supported with early versions of the C
1294 readline library, which provides no way to determine the version at
1295 compile-time.
1296
1297- The binascii module is now enabled on Win64.
1298
Tim Peters46446d62000-10-09 21:19:31 +00001299- tokenize.py no longer suffers "recursion depth" errors when parsing
1300 programs with very long string literals.
1301
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001302Internals
1303
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001304- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001305 which is called when the interpreter starts up to determine where
1306 the standard library is installed. These vulnerabilities affect all
1307 previous versions of Python and can be exploited by setting very
1308 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1309 setuid Python script, although use of the wrapper in
1310 Misc/setuid-prog.c will eliminate the vulnerability.
1311
1312- Fixed garbage collection bugs in instance creation that were
1313 triggered when errors occurred during initialization. The solution,
1314 applied in cPickle and in PyInstance_New(), is to call
1315 PyObject_GC_Init() after the initialization of the object's
1316 container attributes is complete.
1317
1318- pyexpat adds definitions of PyModule_AddStringConstant and
1319 PyModule_AddObject if the Python version is less than 2.0, which
1320 provides compatibility with PyXML on Python 1.5.2.
1321
1322- If the platform has a bogus definition for LONG_BIT (the number of
1323 bits in a long), an error will be reported at compile time.
1324
1325- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1326 collection crashes and possibly other, unreported crashes.
1327
1328- Fixed a memory leak in _PyUnicode_Fini().
1329
1330Build issues
1331
1332- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001333 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001334 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001335
1336- The mmap.PAGESIZE constant is now initialized using sysconf when
1337 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1338
1339- The md5 file should now compile on all platforms.
1340
1341- The select module now compiles on platforms that do not define
1342 POLLRDNORM and related constants.
1343
1344- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001345 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001346
Jeremy Hylton10921202000-10-09 18:34:12 +00001347- BeOS: A number of changes were made to the build and installation
1348 process. ar-fake now operates on a directory of object files.
1349 dl_export.h is gone, and its macros now appear on the mwcc command
1350 line during build on PPC BeOS.
1351
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001352- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001353 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001354
1355- Cygwin: Support for shared libraries, Tkinter, and sockets.
1356
1357- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1358
1359Tools and other miscellany
1360
1361- Removed debugging prints from main used with freeze.
1362
Tim Peters46446d62000-10-09 21:19:31 +00001363- IDLE auto-indent no longer crashes when it encounters Unicode
1364 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001365
1366What's new in 2.0 beta 2 (since beta 1)?
1367========================================
1368
1369Core language, builtins, and interpreter
1370
Tim Peters482c0212000-09-26 06:33:09 +00001371- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001372 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001373
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001374- Add -h and -V command line options to print the usage message and
1375 Python version number and exit immediately.
1376
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001377- eval() and exec accept Unicode objects as code parameters.
1378
1379- getattr() and setattr() now also accept Unicode objects for the
1380 attribute name, which are converted to strings using the default
1381 encoding before lookup.
1382
1383- Multiplication on string and Unicode now does proper bounds
1384 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1385 string is too long."
1386
1387- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001388 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001389
Jeremy Hylton1b618592000-09-26 05:32:36 +00001390
1391Standard library and extensions
1392
Guido van Rossum5b08f132001-04-16 02:05:23 +00001393- socket module: the OpenSSL code now adds support for RAND_status()
1394 and EGD (Entropy Gathering Device).
1395
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001396- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001397 argument checking; it still takes no arguments.
1398
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001399- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001400
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001401- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001402
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001403- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001404
1405- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001406 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001407
1408- copy: Copy Unicode objects atomically.
1409
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001410- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001411
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001412- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001413
Fred Drake67233bc2000-09-26 16:40:27 +00001414- dbm: Add get() and setdefault() methods to dbm object. Add constant
1415 `library' to module that names the library used. Added doc strings
1416 and method names to error messages. Uses configure to determine
1417 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1418 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001419
1420- distutils: Update to version 0.9.3.
1421
1422- dl: Add several dl.RTLD_ constants.
1423
1424- fpectl: Now supported on FreeBSD.
1425
1426- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1427 found by the collector will be saved in gc.garbage. This is useful
1428 for debugging a program that creates reference cycles.
1429
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001430- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001431 of HTTP class. Do not close socket on zero-length response. Do not
1432 crash when server sends invalid content-length header.
1433
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001434- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001435
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001436- marshal: When reading a short, sign-extend on platforms where shorts
1437 are bigger than 16 bits. When reading a long, repair the unportable
1438 sign extension that was being done for 64-bit machines. (It assumed
1439 that signed right shift sign-extends.)
1440
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001441- operator: Add contains(), invert(), __invert__() as aliases for
1442 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001443
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001444- os: Add support for popen2() and popen3() on all platforms where
1445 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001446
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001447- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001448 clicking on a file in Explorer (or passing the file name to the
1449 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001450
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001451- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001452 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001453
1454- pickle: Now raises ValueError when an invalid pickle that contains
1455 a non-string repr where a string repr was expected. This behavior
1456 matches cPickle.
1457
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001458- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001459
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001460- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001461
1462- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001463 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001464 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001465
1466- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001467 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001468
1469- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001470 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001471 few cycles during startup since the first call to
1472 setdefaultencoding() will initialize the codec registry and the
1473 encodings package.
1474
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001475- socket: Support for size hint in readlines() method of object returned
1476 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001477
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001478- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001479 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001480 is followed by whitespace.
1481
Tim Petersa3a3a032000-11-30 05:22:44 +00001482- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001483
1484- struct: Check ranges for bytes and shorts.
1485
1486- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001487 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001488
1489- Tkinter: Image objects are now guaranteed to have unique ids. Set
1490 event.delta to zero if Tk version doesn't support mousewheel.
1491 Removed some debugging prints.
1492
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001493- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001494
Fred Drake67233bc2000-09-26 16:40:27 +00001495- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001496 which works around a bug in Norton AntiVirus 2000 that leads directly
1497 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001498
1499- xml: New version detection code allows PyXML to override standard
1500 XML package if PyXML version is greater than 0.6.1.
1501
Fred Drake64bb3802000-09-26 16:21:35 +00001502- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1503 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1504 tree only for nodes which are sufficiently interesting to a specific
1505 application. Does not provide the HTML-specific extensions. Still
1506 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001507
Fred Drake64bb3802000-09-26 16:21:35 +00001508- xml.sax: SAX 2 support for Python, including all the handler
1509 interfaces needed to process XML 1.0 compliant XML. Some
1510 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001511
Fred Drake64bb3802000-09-26 16:21:35 +00001512- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1513 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001514
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001515
Jeremy Hylton1b618592000-09-26 05:32:36 +00001516C API
1517
1518- Add three new convenience functions for module initialization --
1519 PyModule_AddObject(), PyModule_AddIntConstant(), and
1520 PyModule_AddStringConstant().
1521
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001522- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001523 removed and add #error to Python.h if NULL isn't defined after
1524 #include of stdio.h.
1525
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001526- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001527 backwards compatibility (at the source level) with old extensions.
1528
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001529- A wrapper API was added for signal() and sigaction(). Instead of
1530 either function, always use PyOS_getsig() to get a signal handler
1531 and PyOS_setsig() to set one. A new convenience typedef
1532 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001533
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001534- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001535 internal data buffer and size of a string object -- or the default
1536 encoded version of a Unicode object.
1537
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001538- PyString_Size() and PyString_AsString() accept Unicode objects.
1539
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001540- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001541 exists). INT_MAX and LONG_MAX will always be defined, even if
1542 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001543
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001544- PyFloat_FromString takes a second argument, pend, that was
1545 effectively useless. It is now officially useless but preserved for
1546 backwards compatibility. If the pend argument is not NULL, *pend is
1547 set to NULL.
1548
1549- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1550 for the attribute name. See note on getattr() above.
1551
1552- A few bug fixes to argument processing for Unicode.
1553 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1554 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1555 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001556 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001557
1558- Py_BuildValue accepts B format (for bgen-generated code).
1559
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001560
Jeremy Hylton1b618592000-09-26 05:32:36 +00001561Internals
1562
1563- On Unix, fix code for finding Python installation directory so that
1564 it works when argv[0] is a relative path.
1565
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001566- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001567 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001568 rather than by generating a copy of the object.
1569
Tim Peters482c0212000-09-26 06:33:09 +00001570- Several of the internal Unicode tables are much smaller now, and
1571 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001572
Jeremy Hylton97693b02000-09-26 17:42:51 +00001573- In the garbage collector: Fixed bug in collection of tuples. Fixed
1574 bug that caused some instances to be removed from the container set
1575 while they were still live. Fixed parsing in gc.set_debug() for
1576 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001577
1578- Fixed refcount problem in instance deallocation that only occurred
1579 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1580
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001581- On Windows, getpythonregpath is now protected against null data in
1582 registry key.
1583
1584- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001585 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001586
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001587
Jeremy Hylton1b618592000-09-26 05:32:36 +00001588Build and platform-specific issues
1589
1590- Better support of GNU Pth via --with-pth configure option.
1591
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001592- Python/C API now properly exposed to dynamically-loaded extension
1593 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001594
1595- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1596 Don't define MS_SYNC to be zero when it is undefined. Added missing
1597 prototypes in posixmodule.c.
1598
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001599- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001600 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001601
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001602- Fix largefile support on older NetBSD systems and OpenBSD by adding
1603 define for TELL64.
1604
1605
1606Tools and other miscellany
1607
1608- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1609
1610- freeze: The modulefinder now works with 2.0 opcodes.
1611
Tim Petersa3a3a032000-11-30 05:22:44 +00001612- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001613 Move hackery of sys.argv until after the Tk instance has been
1614 created, which allows the application-specific Tkinter
1615 initialization to be executed if present; also pass an explicit
1616 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001617
Jeremy Hylton1b618592000-09-26 05:32:36 +00001618
1619What's new in 2.0 beta 1?
1620=========================
1621
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001622Source Incompatibilities
1623------------------------
1624
1625None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1626such as single-argument append(), connect() and bind(), and changes to
1627str(long) and repr(float).
1628
1629
1630Binary Incompatibilities
1631------------------------
1632
1633- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1634with Python 2.0; these extensions will have to be rebuilt for Python
16352.0.
1636
1637- On Windows, attempting to import a third party extension built for
1638Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1639can do about this. Check your PYTHONPATH environment variable!
1640
1641- Python bytecode files (*.pyc and *.pyo) are not compatible between
1642releases.
1643
1644
1645Overview of Changes Since 1.6
1646-----------------------------
1647
1648There are many new modules (including brand new XML support through
1649the xml package, and i18n support through the gettext module); a list
1650of all new modules is included below. Lots of bugs have been fixed.
1651
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001652The process for making major new changes to the language has changed
1653since Python 1.6. Enhancements must now be documented by a Python
1654Enhancement Proposal (PEP) before they can be accepted.
1655
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001656There are several important syntax enhancements, described in more
1657detail below:
1658
1659 - Augmented assignment, e.g. x += 1
1660
1661 - List comprehensions, e.g. [x**2 for x in range(10)]
1662
1663 - Extended import statement, e.g. import Module as Name
1664
1665 - Extended print statement, e.g. print >> file, "Hello"
1666
1667Other important changes:
1668
1669 - Optional collection of cyclical garbage
1670
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001671Python Enhancement Proposal (PEP)
1672---------------------------------
1673
1674PEP stands for Python Enhancement Proposal. A PEP is a design
1675document providing information to the Python community, or describing
1676a new feature for Python. The PEP should provide a concise technical
1677specification of the feature and a rationale for the feature.
1678
1679We intend PEPs to be the primary mechanisms for proposing new
1680features, for collecting community input on an issue, and for
1681documenting the design decisions that have gone into Python. The PEP
1682author is responsible for building consensus within the community and
1683documenting dissenting opinions.
1684
1685The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001686
1687Augmented Assignment
1688--------------------
1689
1690This must have been the most-requested feature of the past years!
1691Eleven new assignment operators were added:
1692
Guido van Rossume905e952000-09-05 12:42:46 +00001693 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001694
1695For example,
1696
1697 A += B
1698
1699is similar to
1700
1701 A = A + B
1702
1703except that A is evaluated only once (relevant when A is something
1704like dict[index].attr).
1705
1706However, if A is a mutable object, A may be modified in place. Thus,
1707if A is a number or a string, A += B has the same effect as A = A+B
1708(except A is only evaluated once); but if a is a list, A += B has the
1709same effect as A.extend(B)!
1710
1711Classes and built-in object types can override the new operators in
1712order to implement the in-place behavior; the not-in-place behavior is
1713used automatically as a fallback when an object doesn't implement the
1714in-place behavior. For classes, the method name is derived from the
1715method name for the corresponding not-in-place operator by inserting
1716an 'i' in front of the name, e.g. __iadd__ implements in-place
1717__add__.
1718
1719Augmented assignment was implemented by Thomas Wouters.
1720
1721
1722List Comprehensions
1723-------------------
1724
1725This is a flexible new notation for lists whose elements are computed
1726from another list (or lists). The simplest form is:
1727
1728 [<expression> for <variable> in <sequence>]
1729
Guido van Rossum56db0952000-09-06 23:34:25 +00001730For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001731This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001732
1733You can also add a condition:
1734
1735 [<expression> for <variable> in <sequence> if <condition>]
1736
1737For example, [w for w in words if w == w.lower()] would yield the list
1738of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001739than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001740
1741You can also have nested for loops and more than one 'if' clause. For
1742example, here's a function that flattens a sequence of sequences::
1743
1744 def flatten(seq):
1745 return [x for subseq in seq for x in subseq]
1746
1747 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1748
1749This prints
1750
1751 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1752
1753List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001754Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001755
1756
1757Extended Import Statement
1758-------------------------
1759
1760Many people have asked for a way to import a module under a different
1761name. This can be accomplished like this:
1762
1763 import foo
1764 bar = foo
1765 del foo
1766
1767but this common idiom gets old quickly. A simple extension of the
1768import statement now allows this to be written as follows:
1769
1770 import foo as bar
1771
1772There's also a variant for 'from ... import':
1773
1774 from foo import bar as spam
1775
1776This also works with packages; e.g. you can write this:
1777
1778 import test.regrtest as regrtest
1779
1780Note that 'as' is not a new keyword -- it is recognized only in this
1781context (this is only possible because the syntax for the import
1782statement doesn't involve expressions).
1783
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001784Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001785
1786
1787Extended Print Statement
1788------------------------
1789
1790Easily the most controversial new feature, this extension to the print
1791statement adds an option to make the output go to a different file
1792than the default sys.stdout.
1793
1794For example, to write an error message to sys.stderr, you can now
1795write:
1796
1797 print >> sys.stderr, "Error: bad dog!"
1798
1799As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001800evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001801
1802 print >> None, "Hello world"
1803
1804is equivalent to
1805
1806 print "Hello world"
1807
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001808Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001809
1810
1811Optional Collection of Cyclical Garbage
1812---------------------------------------
1813
1814Python is now equipped with a garbage collector that can hunt down
1815cyclical references between Python objects. It's no replacement for
1816reference counting; in fact, it depends on the reference counts being
1817correct, and decides that a set of objects belong to a cycle if all
1818their reference counts can be accounted for from their references to
1819each other. This devious scheme was first proposed by Eric Tiedemann,
1820and brought to implementation by Neil Schemenauer.
1821
1822There's a module "gc" that lets you control some parameters of the
1823garbage collection. There's also an option to the configure script
1824that lets you enable or disable the garbage collection. In 2.0b1,
1825it's on by default, so that we (hopefully) can collect decent user
1826experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001827performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001828off by default in the final 2.0 release.
1829
1830
1831Smaller Changes
1832---------------
1833
1834A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1835map(None, seq1, seq2, ...) when the sequences have the same length;
1836i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1837the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001838zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001839
1840sys.version_info is a tuple (major, minor, micro, level, serial).
1841
1842Dictionaries have an odd new method, setdefault(key, default).
1843dict.setdefault(key, default) returns dict[key] if it exists; if not,
1844it sets dict[key] to default and returns that value. Thus:
1845
1846 dict.setdefault(key, []).append(item)
1847
1848does the same work as this common idiom:
1849
1850 if not dict.has_key(key):
1851 dict[key] = []
1852 dict[key].append(item)
1853
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001854There are two new variants of SyntaxError that are raised for
1855indentation-related errors: IndentationError and TabError.
1856
1857Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1858escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001859
1860The limits on the size of expressions and file in Python source code
1861have been raised from 2**16 to 2**32. Previous versions of Python
1862were limited because the maximum argument size the Python VM accepted
1863was 2**16. This limited the size of object constructor expressions,
1864e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1865limit was raised thanks to a patch by Charles Waldman that effectively
1866fixes the problem. It is now much more likely that you will be
1867limited by available memory than by an arbitrary limit in Python.
1868
1869The interpreter's maximum recursion depth can be modified by Python
1870programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1871limit is the maximum number of recursive calls that can be made by
1872Python code. The limit exists to prevent infinite recursion from
1873overflowing the C stack and causing a core dump. The default value is
18741000. The maximum safe value for a particular platform can be found
1875by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001876
1877New Modules and Packages
1878------------------------
1879
1880atexit - for registering functions to be called when Python exits.
1881
1882imputil - Greg Stein's alternative API for writing custom import
1883hooks.
1884
1885pyexpat - an interface to the Expat XML parser, contributed by Paul
1886Prescod.
1887
1888xml - a new package with XML support code organized (so far) in three
1889subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1890would fill a volume. There's a special feature whereby a
1891user-installed package named _xmlplus overrides the standard
1892xmlpackage; this is intended to give the XML SIG a hook to distribute
1893backwards-compatible updates to the standard xml package.
1894
1895webbrowser - a platform-independent API to launch a web browser.
1896
1897
Guido van Rossume905e952000-09-05 12:42:46 +00001898Changed Modules
1899---------------
1900
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001901array -- new methods for array objects: count, extend, index, pop, and
1902remove
1903
1904binascii -- new functions b2a_hex and a2b_hex that convert between
1905binary data and its hex representation
1906
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001907calendar -- Many new functions that support features including control
1908over which day of the week is the first day, returning strings instead
1909of printing them. Also new symbolic constants for days of week,
1910e.g. MONDAY, ..., SUNDAY.
1911
1912cgi -- FieldStorage objects have a getvalue method that works like a
1913dictionary's get method and returns the value attribute of the object.
1914
1915ConfigParser -- The parser object has new methods has_option,
1916remove_section, remove_option, set, and write. They allow the module
1917to be used for writing config files as well as reading them.
1918
1919ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001920optionally support the RFC 959 REST command.
1921
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001922gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001923
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001924httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1925the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001926
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001927locale -- implement getdefaultlocale for Win32 and Macintosh
1928
1929marshal -- no longer dumps core when marshaling deeply nested or
1930recursive data structures
1931
1932os -- new functions isatty, seteuid, setegid, setreuid, setregid
1933
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001934os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1935support under Unix.
1936
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001937os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001938
1939os.path -- fix semantics of os.path.commonprefix
1940
1941smtplib -- support for sending very long messages
1942
1943socket -- new function getfqdn()
1944
1945readline -- new functions to read, write and truncate history files.
1946The readline section of the library reference manual contains an
1947example.
1948
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001949select -- add interface to poll system call
1950
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001951shutil -- new copyfileobj function
1952
1953SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1954HTTP server.
1955
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001956Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001957
1958urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001959e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001960
1961whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001962
1963
1964Obsolete Modules
1965----------------
1966
1967None. However note that 1.6 made a whole slew of modules obsolete:
1968stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1969poly, zmod, strop, util, whatsound.
1970
1971
1972Changed, New, Obsolete Tools
1973----------------------------
1974
Tim Peters8b092332000-09-05 20:15:25 +00001975None.
Guido van Rossume905e952000-09-05 12:42:46 +00001976
1977
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001978C-level Changes
1979---------------
1980
1981Several cleanup jobs were carried out throughout the source code.
1982
1983All C code was converted to ANSI C; we got rid of all uses of the
1984Py_PROTO() macro, which makes the header files a lot more readable.
1985
1986Most of the portability hacks were moved to a new header file,
1987pyport.h; several other new header files were added and some old
1988header files were removed, in an attempt to create a more rational set
1989of header files. (Few of these ever need to be included explicitly;
1990they are all included by Python.h.)
1991
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001992Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001993and Win64, especially for the new Intel Itanium processor. Mick also
1994added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001995
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001996The C APIs to return an object's size have been update to consistently
1997use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1998previous versions, the abstract interfaces used PyXXX_Length and the
1999concrete interfaces used PyXXX_Size. The old names,
2000e.g. PyObject_Length, are still available for backwards compatibility
2001at the API level, but are deprecated.
2002
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002003The PyOS_CheckStack function has been implemented on Windows by
2004Fredrik Lundh. It prevents Python from failing with a stack overflow
2005on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002006
2007The GC changes resulted in creation of two new slots on object,
2008tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002009the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002010
2011The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002012C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002013
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002014PyErr_Format has been updated to automatically calculate the size of
2015the buffer needed to hold the formatted result string. This change
2016prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002017
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002018New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002019
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002020PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2021that are the same as their non-Ex counterparts except they take an
2022extra flag argument that tells them to close the file when done.
2023
2024XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002025
Tim Peters8b092332000-09-05 20:15:25 +00002026
2027Windows Changes
2028---------------
2029
2030New popen2/popen3/peopen4 in os module (see Changed Modules above).
2031
2032os.popen is much more usable on Windows 95 and 98. See Microsoft
2033Knowledge Base article Q150956. The Win9x workaround described there
2034is implemented by the new w9xpopen.exe helper in the root of your
2035Python installation. Note that Python uses this internally; it is not
2036a standalone program.
2037
2038Administrator privileges are no longer required to install Python
2039on Windows NT or Windows 2000. If you have administrator privileges,
2040Python's registry info will be written under HKEY_LOCAL_MACHINE.
2041Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002042under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002043uses of Python, but will prevent some advanced uses from working
2044(for example, running a Python script as an NT service, or possibly
2045from CGI).
2046
2047[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2048installer; instead, it installs the needed Tcl/Tk files directly in the
2049Python directory. If you already have a Tcl/Tk installation, this
2050wastes some disk space (about 4 Megs) but avoids problems with
2051conflicting Tcl/Tk installations, and makes it much easier for Python
2052to ensure that Tcl/Tk can find all its files.
2053
2054[This was new in 1.6] The Windows installer now installs by default in
2055\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2056
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002057
2058Updates to the changes between 1.5.2 and 1.6
2059--------------------------------------------
2060
2061The 1.6 NEWS file can't be changed after the release is done, so here
2062is some late-breaking news:
2063
2064New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2065and changes to getlocale() and setlocale().
2066
2067The new module is now enabled per default.
2068
2069It is not true that the encodings codecs cannot be used for normal
2070strings: the string.encode() (which is also present on 8-bit strings
2071!) allows using them for 8-bit strings too, e.g. to convert files from
2072cp1252 (Windows) to latin-1 or vice-versa.
2073
2074Japanese codecs are available from Tamito KAJIYAMA:
2075http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2076
2077
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002078======================================================================