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Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001What's New in Python 2.1 beta 2?
2================================
3
Guido van Rossum053ae352001-03-22 14:17:21 +00004(Unlisted are many fixed bugs, more documentation, etc.)
5
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00006Core language, builtins, and interpreter
7
Guido van Rossum053ae352001-03-22 14:17:21 +00008- The nested scopes work (enabled by "from __future__ import
9 nested_scopes") is completed; in particular, the future now extends
10 into code executed through exec, eval() and execfile(), and into the
11 interactive interpreter.
12
13- When calling a base class method (e.g. BaseClass.__init__(self)),
14 this is now allowed even if self is not strictly spoken a class
15 instance (e.g. when using metaclasses or the Don Beaudry hook).
16
17- Slice objects are now comparable but not hashable; this prevents
18 dict[:] from being accepted but meaningless.
19
20- Complex division is now calculated using less braindead algorithms.
21 This doesn't change semantics except it's more likely to give useful
22 results in extreme cases. Complex repr() now uses full precision
23 like float repr().
24
25- sgmllib.py now calls handle_decl() for simple <!...> declarations.
26
Martin v. Löwis0411f6f2001-03-21 08:01:39 +000027Standard library
28
Guido van Rossum053ae352001-03-22 14:17:21 +000029- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
30 inspired by JUnit), is now part of the standard library. You now
31 have a choice of two testing frameworks: unittest requires you to
32 write testcases as separate code, doctest gathers them from
33 docstrings. Both approaches have their advantages and
34 disadvantages.
35
36- A new module Tix was added, which wraps the Tix extension library
37 for Tk. With that module, it is not necessary to statically link
38 Tix with _tkinter, since Tix will be loaded with Tcl's "package
39 require" command. See Demo/tix/.
40
41- tzparse.py is now obsolete.
42
43- In gzip.py, the seek() and tell() methods are removed -- they were
44 non-functional anyway, and it's better if callers can test for their
45 existence with hasattr().
46
47Python/C API
48
49- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
50 that's already in the dictionary during a PyDict_Next() iteration.
51 This used to fail occasionally when a dictionary resize operation
52 could be triggered that would rehash all the keys. All other
53 modifications to the dictionary are still off-limits during a
54 PyDict_Next() iteration!
55
56- New extended APIs related to passing compiler variables around.
57
58- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
59 implement isinstance() and issubclass().
60
61- Py_BuildValue() now has a "D" conversion to create a Python complex
62 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +000063
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +000064Distutils
65
66- the sdist command now writes a PKG-INFO file, as described in PEP 241,
67 into the release tree.
68
69- several enhancements to the bdist_wininst command from Thomas Heller
70 (an uninstaller, more customization of the installer's display)
71
72- from Jack Jansen: added Mac-specific code to generate a dialog for
73 users to specify the command-line (because providing a command-line with
74 MacPython is awkward). Jack also made various fixes for the Mac
75 and the Metrowerks compiler.
76
77- added 'platforms' and 'keywords' to the set of metadata that can be
78 specified for a distribution. Supplying a version number has been made
79 compulsory.
80
81- applied patches from Jason Tishler to make the compiler class work with
82 Cygwin.
83
84
Tim Peters2fe289a2001-03-01 22:19:38 +000085What's New in Python 2.1 beta 1?
86================================
Tim Petersd66595f2001-02-04 03:09:53 +000087
88Core language, builtins, and interpreter
89
Guido van Rossum9d0fbde2001-03-02 14:00:32 +000090- Following an outcry from the community about the amount of code
91 broken by the nested scopes feature introduced in 2.1a2, we decided
92 to make this feature optional, and to wait until Python 2.2 (or at
93 least 6 months) to make it standard. The option can be enabled on a
94 per-module basis by adding "from __future__ import nested_scopes" at
95 the beginning of a module (before any other statements, but after
96 comments and an optional docstring). See PEP 236 (Back to the
97 __future__) for a description of the __future__ statement. PEP 227
98 (Statically Nested Scopes) has been updated to reflect this change,
99 and to clarify the semantics in a number of endcases.
100
101- The nested scopes code, when enabled, has been hardened, and most
102 bugs and memory leaks in it have been fixed.
103
104- Compile-time warnings are now generated for a number of conditions
105 that will break or change in meaning when nested scopes are enabled:
106
107 - Using "from...import *" or "exec" without in-clause in a function
108 scope that also defines a lambda or nested function with one or
109 more free (non-local) variables. The presence of the import* or
110 bare exec makes it impossible for the compiler to determine the
111 exact set of local variables in the outer scope, which makes it
112 impossible to determine the bindings for free variables in the
113 inner scope. To avoid the warning about import *, change it into
114 an import of explicitly name object, or move the import* statement
115 to the global scope; to avoid the warning about bare exec, use
116 exec...in... (a good idea anyway -- there's a possibility that
117 bare exec will be deprecated in the future).
118
119 - Use of a global variable in a nested scope with the same name as a
120 local variable in a surrounding scope. This will change in
121 meaning with nested scopes: the name in the inner scope will
122 reference the variable in the outer scope rather than the global
123 of the same name. To avoid the warning, either rename the outer
124 variable, or use a global statement in the inner function.
125
Neil Schemenauera35c6882001-02-27 04:45:05 +0000126- An optional object allocator has been included. This allocator is
127 optimized for Python objects and should be faster and use less memory
128 than the standard system allocator. It is not enabled by default
129 because of possible thread safety problems. The allocator is only
130 protected by the Python interpreter lock and it is possible that some
131 extension modules require a thread safe allocator. The object
132 allocator can be enabled by providing the "--with-pymalloc" option to
133 configure.
134
Tim Petersd66595f2001-02-04 03:09:53 +0000135Standard library
136
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000137- pyexpat now detects the expat version if expat.h defines it. A
138 number of additional handlers are provided, which are only available
139 since expat 1.95. In addition, the methods SetParamEntityParsing and
140 GetInputContext of Parser objects are available with 1.95.x
141 only. Parser objects now provide the ordered_attributes and
142 specified_attributes attributes. A new module expat.model was added,
143 which offers a number of additional constants if 1.95.x is used.
144
145- xml.dom offers the new functions registerDOMImplementation and
146 getDOMImplementation.
147
148- xml.dom.minidom offers a toprettyxml method. A number of DOM
149 conformance issues have been resolved. In particular, Element now
150 has an hasAttributes method, and the handling of namespaces was
151 improved.
152
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000153- Ka-Ping Yee contributed two new modules: inspect.py, a module for
154 getting information about live Python code, and pydoc.py, a module
155 for interactively converting docstrings to HTML or text.
156 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000157 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000158 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
159 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000160
Tim Peters1eff7962001-03-01 02:31:33 +0000161- New library module difflib.py, primarily packaging the SequenceMatcher
162 class at the heart of the popular ndiff.py file-comparison tool.
163
164- doctest.py (a framework for verifying Python code examples in docstrings)
165 is now part of the std library.
166
Tim Petersd66595f2001-02-04 03:09:53 +0000167Windows changes
168
Guido van Rossume3955a82001-03-02 14:05:59 +0000169- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
170 small GUI that lets you browse the module docstrings using your
171 default web browser.
172
Tim Peters1eff7962001-03-01 02:31:33 +0000173- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
174 Platforms) is implemented. See
175
176 http://python.sourceforge.net/peps/pep-0235.html
177
178 for full details, especially the "Current Lower-Left Semantics" section.
179 The new Windows import rules are simpler than before:
180
181 A. If the PYTHONCASEOK environment variable exists, same as
182 before: silently accept the first case-insensitive match of any
183 kind; raise ImportError if none found.
184
185 B. Else search sys.path for the first case-sensitive match; raise
186 ImportError if none found.
187
188 The same rules have been implented on other platforms with case-
189 insensitive but case-preserving filesystems too (including Cygwin, and
190 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000191
Tim Peters25a9ce32001-02-19 07:06:36 +0000192- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
193 what it's supposed to do (and does do under NT and 2000) via direct
194 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000195 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000196 all Win9x systems before.
197
Tim Peters1eff7962001-03-01 02:31:33 +0000198- Build: Subproject _test (effectively) renamed to _testcapi.
199
Tim Peters2fe289a2001-03-01 22:19:38 +0000200New platforms
201
202- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
203 Thanks to Steven Majewski!
204
205- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
206 Tishler!
207
Guido van Rossum9089b272001-03-02 06:49:50 +0000208- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
209 Schwertberger! See RISCOS/README for more information -- it seems
210 that because of the bizarre filename conventions on RISCOS, no port
211 to that platform is easy. Note that the new variable os.endsep is
212 silently supported in order to make life easier on this platform,
213 but we don't advertise it because it's not worth for most folks to
214 care about RISCOS portability.
215
Tim Peters25a9ce32001-02-19 07:06:36 +0000216
Tim Petersd7b5e882001-01-25 03:36:26 +0000217What's New in Python 2.1 alpha 2?
218=================================
Tim Peters40ead762001-01-27 05:35:26 +0000219
Tim Petersd7b5e882001-01-25 03:36:26 +0000220Core language, builtins, and interpreter
221
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000222- Scopes nest. If a name is used in a function or class, but is not
223 local, the definition in the nearest enclosing function scope will
224 be used. One consequence of this change is that lambda statements
225 could reference variables in the namespaces where the lambda is
226 defined. In some unusual cases, this change will break code.
227
228 In all previous version of Python, names were resolved in exactly
229 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000230 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000231 function A is defined within a function B, the names bound in B are
232 not visible in A. The new rules make names bound in B visible in A,
233 unless A contains a name binding that hides the binding in B.
234
235 Section 4.1 of the reference manual describes the new scoping rules
236 in detail. The test script in Lib/test/test_scope.py demonstrates
237 some of the effects of the change.
238
239 The new rules will cause existing code to break if it defines nested
240 functions where an outer function has local variables with the same
241 name as globals or builtins used by the inner function. Example:
242
243 def munge(str):
244 def helper(x):
245 return str(x)
246 if type(str) != type(''):
247 str = helper(str)
248 return str.strip()
249
250 Under the old rules, the name str in helper() is bound to the
251 builtin function str(). Under the new rules, it will be bound to
252 the argument named str and an error will occur when helper() is
253 called.
254
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000255- The compiler will report a SyntaxError if "from ... import *" occurs
256 in a function or class scope. The language reference has documented
257 that this case is illegal, but the compiler never checked for it.
258 The recent introduction of nested scope makes the meaning of this
259 form of name binding ambiguous. In a future release, the compiler
260 may allow this form when there is no possibility of ambiguity.
261
Tim Peters40ead762001-01-27 05:35:26 +0000262- repr(string) is easier to read, now using hex escapes instead of octal,
263 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
264
265 >>> "\texample \r\n" + chr(0) + chr(255)
266 '\texample \r\n\x00\xff' # in 2.1
267 '\011example \015\012\000\377' # in 2.0
268
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000269- Functions are now compared and hashed by identity, not by value, since
270 the func_code attribute is writable.
271
Fred Drakefb9d7122001-02-01 20:00:40 +0000272- Weak references (PEP 205) have been added. This involves a few
273 changes in the core, an extension module (_weakref), and a Python
274 module (weakref). The weakref module is the public interface. It
275 includes support for "explicit" weak references, proxy objects, and
276 mappings with weakly held values.
277
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000278- A 'continue' statement can now appear in a try block within the body
279 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000280 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000281
Tim Petersd7b5e882001-01-25 03:36:26 +0000282Standard library
283
Barry Warsaw30dbd142001-01-31 22:14:01 +0000284- mailbox.py now has a new class, PortableUnixMailbox which is
285 identical to UnixMailbox but uses a more portable scheme for
286 determining From_ separators. Also, the constructors for all the
287 classes in this module have a new optional `factory' argument, which
288 is a callable used when new message classes must be instantiated by
289 the next() method.
290
Tim Petersd7b5e882001-01-25 03:36:26 +0000291- random.py is now self-contained, and offers all the functionality of
292 the now-deprecated whrandom.py. See the docs for details. random.py
293 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000294 and restoring the internal state of the generator; and jumpahead(n),
295 for quickly forcing the internal state to be the same as if n calls to
296 random() had been made. The latter is particularly useful for multi-
297 threaded programs, creating one instance of the random.Random() class for
298 each thread, then using .jumpahead() to force each instance to use a
299 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000300
Tim Peters0de88fc2001-02-01 04:59:18 +0000301- random.py's seed() function is new. For bit-for-bit compatibility with
302 prior releases, use the whseed function instead. The new seed function
303 addresses two problems: (1) The old function couldn't produce more than
304 about 2**24 distinct internal states; the new one about 2**45 (the best
305 that can be done in the Wichmann-Hill generator). (2) The old function
306 sometimes produced identical internal states when passed distinct
307 integers, and there was no simple way to predict when that would happen;
308 the new one guarantees to produce distinct internal states for all
309 arguments in [0, 27814431486576L).
310
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000311- The socket module now supports raw packets on Linux. The socket
312 family is AF_PACKET.
313
Tim Peters9ea17ac2001-02-02 05:57:15 +0000314- test_capi.py is a start at running tests of the Python C API. The tests
315 are implemented by the new Modules/_testmodule.c.
316
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000317- A new extension module, _symtable, provides provisional access to the
318 internal symbol table used by the Python compiler. A higher-level
319 interface will be added on top of _symtable in a future release.
320
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000321- Removed the obsolete soundex module.
322
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000323- xml.dom.minidom now uses the standard DOM exceptions. Node supports
324 the isSameNode method; NamedNodeMap the get method.
325
326- xml.sax.expatreader supports the lexical handler property; it
327 generates comment, startCDATA, and endCDATA events.
328
Tim Petersee826f82001-01-31 19:39:44 +0000329Windows changes
330
331- Build procedure: the zlib project is built in a different way that
332 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000333 the zlib binary used. See PCbuild\readme.txt for details. Your old
334 zlib-related directories can be deleted; you'll need to download fresh
335 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000336
Tim Peters9ea17ac2001-02-02 05:57:15 +0000337- Build: New subproject _test for the benefit of test_capi.py (see above).
338
Tim Petersb16c56f2001-02-02 21:24:51 +0000339- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
340 interface to some Python compiler internals).
341
342- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000343 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000344
Tim Petersa3a3a032000-11-30 05:22:44 +0000345What's New in Python 2.1 alpha 1?
346=================================
347
348Core language, builtins, and interpreter
349
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000350- There is a new Unicode companion to the PyObject_Str() API
351 called PyObject_Unicode(). It behaves in the same way as the
352 former, but assures that the returned value is an Unicode object
353 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000354
Guido van Rossumf98eda02001-01-17 15:54:45 +0000355- The comparison operators support "rich comparison overloading" (PEP
356 207). C extension types can provide a rich comparison function in
357 the new tp_richcompare slot in the type object. The cmp() function
358 and the C function PyObject_Compare() first try the new rich
359 comparison operators before trying the old 3-way comparison. There
360 is also a new C API PyObject_RichCompare() (which also falls back on
361 the old 3-way comparison, but does not constrain the outcome of the
362 rich comparison to a Boolean result).
363
364 The rich comparison function takes two objects (at least one of
365 which is guaranteed to have the type that provided the function) and
366 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
367 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
368 object, which may be NotImplemented (in which case the tp_compare
369 slot function is used as a fallback, if defined).
370
371 Classes can overload individual comparison operators by defining one
372 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000373 __ge__. There are no explicit "reflected argument" versions of
374 these; instead, __lt__ and __gt__ are each other's reflection,
375 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
376 reflection (similar at the C level). No other implications are
377 made; in particular, Python does not assume that == is the Boolean
378 inverse of !=, or that < is the Boolean inverse of >=. This makes
379 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000380
381 Classes or types that want to implement (in)equality tests but not
382 the ordering operators (i.e. unordered types) should implement ==
383 and !=, and raise an error for the ordering operators.
384
Guido van Rossuma88479f2001-01-18 14:28:08 +0000385 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000386 Boolean; e.g. a matrix type might want to return a matrix of bits
387 for A < B, giving elementwise comparisons. Such types should ensure
388 that any interpretation of their value in a Boolean context raises
389 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
390 at the C level) to always raise an exception.
391
Guido van Rossuma88479f2001-01-18 14:28:08 +0000392- Complex numbers use rich comparisons to define == and != but raise
393 an exception for <, <=, > and >=. Unfortunately, this also means
394 that cmp() of two complex numbers raises an exception when the two
395 numbers differ. Since it is not mathematically meaningful to compare
396 complex numbers except for equality, I hope that this doesn't break
397 too much code.
398
Tim Peters3389f192001-02-18 08:48:49 +0000399- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000400 not defined by the language, other than that it's arbitrary but
401 consistent (see the Reference Manual). An implementation detail changed
402 in 2.1a1 such that None now compares less than any other object. Code
403 relying on this new behavior (like code that relied on the previous
404 behavior) does so at its own risk.
405
Barry Warsaw573b5412001-01-15 20:43:18 +0000406- Functions and methods now support getting and setting arbitrarily
407 named attributes (PEP 232). Functions have a new __dict__
408 (a.k.a. func_dict) which hold the function attributes. Methods get
409 and set attributes on their underlying im_func. It is a TypeError
410 to set an attribute on a bound method.
411
Guido van Rossum051e3352001-01-15 19:11:10 +0000412- The xrange() object implementation has been improved so that
413 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
414 limitation that in this case len(xrange(sys.maxint)) can't be
415 calculated, but the common idiom "for i in xrange(sys.maxint)" will
416 work fine as long as the index i doesn't actually reach 2**31.
417 (Python uses regular ints for sequence and string indices; fixing
418 that is much more work.)
419
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000420- Two changes to from...import:
421
Guido van Rossumba381232001-02-03 15:06:40 +0000422 1) "from M import X" now works even if (after loading module M)
423 sys.modules['M'] is not a real module; it's basically a getattr()
424 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000425
426 2) "from M import *" now looks for M.__all__ to decide which names to
427 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
428 filters out names starting with '_' as before. Whether or not
429 __all__ exists, there's no restriction on the type of M.
430
Guido van Rossumf61f1662001-01-10 20:13:55 +0000431- File objects have a new method, xreadlines(). This is the fastest
432 way to iterate over all lines in a file:
433
434 for line in file.xreadlines():
435 ...do something to line...
436
437 See the xreadlines module (mentioned below) for how to do this for
438 other file-like objects.
439
440- Even if you don't use file.xreadlines(), you may expect a speedup on
441 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000442 quite a bit in platform-specific ways: on systems (like Linux) that
443 support flockfile(), getc_unlocked(), and funlockfile(), those are
444 used by default. On systems (like Windows) without getc_unlocked(),
445 a complicated (but still thread-safe) method using fgets() is used by
446 default.
447
Tim Petersd52269b2001-01-25 06:23:18 +0000448 You can force use of the fgets() method by #define'ing
449 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000450 getc_unlocked()).
451
Tim Petersd52269b2001-01-25 06:23:18 +0000452 You can force fgets() not to be used by #define'ing
453 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000454 test_bufio.py fails -- and let us know if it does!).
455
456- In addition, the fileinput module, while still slower than the other
457 methods on most platforms, has been sped up too, by using
458 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000459
460- Support for run-time warnings has been added, including a new
461 command line option (-W) to specify the disposition of warnings.
462 See the description of the warnings module below.
463
464- Extensive changes have been made to the coercion code. This mostly
465 affects extension modules (which can now implement mixed-type
466 numerical operators without having to use coercion), but
467 occasionally, in boundary cases the coercion semantics have changed
468 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000469 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000470 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000471 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000472
Guido van Rossumf98eda02001-01-17 15:54:45 +0000473- In connection with the coercion changes, a new built-in singleton
474 object, NotImplemented is defined. This can be returned for
475 operations that wish to indicate they are not implemented for a
476 particular combination of arguments. From C, this is
477 Py_NotImplemented.
478
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000479- The interpreter accepts now bytecode files on the command line even
480 if they do not have a .pyc or .pyo extension. On Linux, after executing
481
Martin v. Löwise214baa2001-02-04 22:37:56 +0000482import imp,sys,string
483magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
484reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
485open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000486
487 any byte code file can be used as an executable (i.e. as an argument
488 to execve(2)).
489
Tim Peters9940b802000-12-01 07:59:35 +0000490- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000491 character. In 1.6 and earlier, they never produced a sign,
492 and raised an error if the value of the long was too large
493 to fit in a Python int. In 2.0, they produced a sign if and
494 only if too large to fit in an int. This was inconsistent
495 across platforms (because the size of an int varies across
496 platforms), and inconsistent with hex() and oct(). Example:
497
498 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000499 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000500 'ffffffbe' # in 2.0 and before, on 32-bit machines
501 >>> hex(-0x42L)
502 '-0x42L' # in all versions of Python
503
Tim Peters9940b802000-12-01 07:59:35 +0000504 The behavior of %d formats for negative Python longs remains
505 the same as in 2.0 (although in 1.6 and before, they raised
506 an error if the long didn't fit in a Python int).
507
508 %u formats don't make sense for Python longs, but are allowed
509 and treated the same as %d in 2.1. In 2.0, a negative long
510 formatted via %u produced a sign if and only if too large to
511 fit in an int. In 1.6 and earlier, a negative long formatted
512 via %u raised an error if it was too big to fit in an int.
513
Guido van Rossum3661d392000-12-12 22:10:31 +0000514- Dictionary objects have an odd new method, popitem(). This removes
515 an arbitrary item from the dictionary and returns it (in the form of
516 a (key, value) pair). This can be useful for algorithms that use a
517 dictionary as a bag of "to do" items and repeatedly need to pick one
518 item. Such algorithms normally end up running in quadratic time;
519 using popitem() they can usually be made to run in linear time.
520
Tim Peters36cdad12000-12-29 02:06:45 +0000521Standard library
522
Thomas Woutersfe385252001-01-19 23:16:56 +0000523- In the time module, the time argument to the functions strftime,
524 localtime, gmtime, asctime and ctime is now optional, defaulting to
525 the current time (in the local timezone).
526
Guido van Rossumda91f222001-01-15 16:36:08 +0000527- The ftplib module now defaults to passive mode, which is deemed a
528 more useful default given that clients are often inside firewalls
529 these days. Note that this could break if ftplib is used to connect
530 to a *server* that is inside a firewall, from outside; this is
531 expected to be a very rare situation. To fix that, you can call
532 ftp.set_pasv(0).
533
Martin v. Löwis10a27872001-01-13 09:54:41 +0000534- The module site now treats .pth files not only for path configuration,
535 but also supports extensions to the initialization code: Lines starting
536 with import are executed.
537
Guido van Rossumf61f1662001-01-10 20:13:55 +0000538- There's a new module, warnings, which implements a mechanism for
539 issuing and filtering warnings. There are some new built-in
540 exceptions that serve as warning categories, and a new command line
541 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
542 turns warnings into errors). warnings.warn(message[, category])
543 issues a warning message; this can also be called from C as
544 PyErr_Warn(category, message).
545
546- A new module xreadlines was added. This exports a single factory
547 function, xreadlines(). The intention is that this code is the
548 absolutely fastest way to iterate over all lines in an open
549 file(-like) object:
550
551 import xreadlines
552 for line in xreadlines.xreadlines(file):
553 ...do something to line...
554
555 This is equivalent to the previous the speed record holder using
556 file.readlines(sizehint). Note that if file is a real file object
557 (as opposed to a file-like object), this is equivalent:
558
559 for line in file.xreadlines():
560 ...do something to line...
561
Tim Peters36cdad12000-12-29 02:06:45 +0000562- The bisect module has new functions bisect_left, insort_left,
563 bisect_right and insort_right. The old names bisect and insort
564 are now aliases for bisect_right and insort_right. XXX_right
565 and XXX_left methods differ in what happens when the new element
566 compares equal to one or more elements already in the list: the
567 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000568 right. Code that doesn't care where equal elements end up should
569 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000570
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000571- The new curses.panel module wraps the panel library that forms part
572 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
573
Guido van Rossumf61f1662001-01-10 20:13:55 +0000574- The SocketServer module now sets the allow_reuse_address flag by
575 default in the TCPServer class.
576
577- A new function, sys._getframe(), returns the stack frame pointer of
578 the caller. This is intended only as a building block for
579 higher-level mechanisms such as string interpolation.
580
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000581- The pyexpat module supports a number of new handlers, which are
582 available only in expat 1.2. If invocation of a callback fails, it
583 will report an additional frame in the traceback. Parser objects
584 participate now in garbage collection. If expat reports an unknown
585 encoding, pyexpat will try to use a Python codec; that works only
586 for single-byte charsets. The parser type objects is exposed as
587 XMLParserObject.
588
589- xml.dom now offers standard definitions for symbolic node type and
590 exception code constants, and a hierarchy of DOM exceptions. minidom
591 was adjusted to use them.
592
593- The conformance of xml.dom.minidom to the DOM specification was
594 improved. It detects a number of additional error cases; the
595 previous/next relationship works even when the tree is modified;
596 Node supports the normalize() method; NamedNodeMap, DocumentType and
597 DOMImplementation classes were added; Element supports the
598 hasAttribute and hasAttributeNS methods; and Text supports the splitText
599 method.
600
Guido van Rossumf61f1662001-01-10 20:13:55 +0000601Build issues
602
Guido van Rossum1e33bdc2001-01-23 03:17:00 +0000603- For Unix (and Unix-compatible) builds, configuration and building of
604 extension modules is now greatly automated. Rather than having to
605 edit the Modules/Setup file to indicate which modules should be
606 built and where their include files and libraries are, a
607 distutils-based setup.py script now takes care of building most
608 extension modules. All extension modules built this way are built
609 as shared libraries. Only a few modules that must be linked
610 statically are still listed in the Setup file; you won't need to
611 edit their configuration.
612
613- Python should now build out of the box on Cygwin. If it doesn't,
614 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000615
616- Python now always uses its own (renamed) implementation of getopt()
617 -- there's too much variation among C library getopt()
618 implementations.
619
620- C++ compilers are better supported; the CXX macro is always set to a
621 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +0000622
Tim Petersd92dfe02000-12-12 01:18:41 +0000623Windows changes
624
625- select module: By default under Windows, a select() call
626 can specify no more than 64 sockets. Python now boosts
627 this Microsoft default to 512. If you need even more than
628 that, see the MS docs (you'll need to #define FD_SETSIZE
629 and recompile Python from source).
630
Guido van Rossumf61f1662001-01-10 20:13:55 +0000631- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
632 subdirectory is no more!
633
Tim Petersa3a3a032000-11-30 05:22:44 +0000634
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000635What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +0000636=========================
Guido van Rossum61000331997-08-15 04:39:58 +0000637
Guido van Rossum8ed602b2000-09-01 22:34:33 +0000638Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000639changes are in the file HISTORY. If you are making the jump directly
640from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
641HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +0000642
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000643Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
644the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
645http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +0000646
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000647--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +0000648
649======================================================================
650
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000651What's new in 2.0 (since release candidate 1)?
652==============================================
653
654Standard library
655
656- The copy_reg module was modified to clarify its intended use: to
657 register pickle support for extension types, not for classes.
658 pickle() will raise a TypeError if it is passed a class.
659
660- Fixed a bug in gettext's "normalize and expand" code that prevented
661 it from finding an existing .mo file.
662
663- Restored support for HTTP/0.9 servers in httplib.
664
Tim Peters989b7b92000-10-16 20:24:53 +0000665- The math module was changed to stop raising OverflowError in case of
666 underflow, and return 0 instead in underflow cases. Whether Python
667 used to raise OverflowError in case of underflow was platform-
668 dependent (it did when the platform math library set errno to ERANGE
669 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000670
671- Fixed a bug in StringIO that occurred when the file position was not
672 at the end of the file and write() was called with enough data to
673 extend past the end of the file.
674
675- Fixed a bug that caused Tkinter error messages to get lost on
676 Windows. The bug was fixed by replacing direct use of
677 interp->result with Tcl_GetStringResult(interp).
678
679- Fixed bug in urllib2 that caused it to fail when it received an HTTP
680 redirect response.
681
682- Several changes were made to distutils: Some debugging code was
683 removed from util. Fixed the installer used when an external zip
684 program (like WinZip) is not found; the source code for this
685 installer is in Misc/distutils. check_lib() was modified to behave
686 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
687 test for whether installed modules are on sys.path was changed to
688 use both normcase() and normpath().
689
Jeremy Hyltond867a2c2000-10-16 20:41:38 +0000690- Several minor bugs were fixed in the xml package (the minidom,
691 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000692
693- The regression test driver (regrtest.py) behavior when invoked with
694 -l changed: It now reports a count of objects that are recognized as
695 garbage but not freed by the garbage collector.
696
Tim Peters989b7b92000-10-16 20:24:53 +0000697- The regression test for the math module was changed to test
698 exceptional behavior when the test is run in verbose mode. Python
699 cannot yet guarantee consistent exception behavior across platforms,
700 so the exception part of test_math is run only in verbose mode, and
701 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000702
703Internals
704
705- PyOS_CheckStack() has been disabled on Win64, where it caused
706 test_sre to fail.
707
708Build issues
709
710- Changed compiler flags, so that gcc is always invoked with -Wall and
711 -Wstrict-prototypes. Users compiling Python with GCC should see
712 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +0000713 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +0000714 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000715
Tim Petersa3a3a032000-11-30 05:22:44 +0000716- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000717
718Tools and other miscellany
719
720- The compiler in Tools/compiler was updated to support the new
721 language features introduced in 2.0: extended print statement, list
722 comprehensions, and augmented assignments. The new compiler should
723 also be backwards compatible with Python 1.5.2; the compiler will
724 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +0000725 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000726
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000727What's new in 2.0 release candidate 1 (since beta 2)?
728=====================================================
729
Jeremy Hylton6040aaa2000-10-09 21:27:22 +0000730What is release candidate 1?
731
732We believe that release candidate 1 will fix all known bugs that we
733intend to fix for the 2.0 final release. This release should be a bit
734more stable than the previous betas. We would like to see even more
735widespread testing before the final release, so we are producing this
736release candidate. The final release will be exactly the same unless
737any show-stopping (or brown bag) bugs are found by testers of the
738release candidate.
739
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000740All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000741to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000742
743Core language, builtins, and interpreter
744
745- A bug that caused crashes when __coerce__ was used with augmented
746 assignment, e.g. +=, was fixed.
747
748- Raise ZeroDivisionError when raising zero to a negative number,
749 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
750 power operator and the result of math.pow(0.0, -2.0) will vary by
751 platform. On Linux, it raises a ValueError.
752
753- A bug in Unicode string interpolation was fixed that occasionally
754 caused errors with formats including "%%". For example, the
755 following expression "%% %s" % u"abc" no longer raises a TypeError.
756
757- Compilation of deeply nested expressions raises MemoryError instead
758 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
759
760- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
761 rendering them useless. They are now written in binary mode again.
762
763Standard library
764
765- Keyword arguments are now accepted for most pattern and match object
766 methods in SRE, the standard regular expression engine.
767
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000768- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +0000769 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000770
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000771- Several bugs in the Unicode handling and error handling in _tkinter
772 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000773
774- Fix memory management errors in Merge() and Tkapp_Call() routines.
775
776- Several changes were made to cStringIO to make it compatible with
777 the file-like object interface and with StringIO. If operations are
778 performed on a closed object, an exception is raised. The truncate
779 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +0000780 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000781
782- There were many changes made to the linuxaudiodev module and its
783 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +0000784 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000785
786 Note that this module is named poorly, because it should work
787 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +0000788 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000789
790 The module now raises exceptions when errors occur instead of
791 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
792 audio) and defines a getptr() method that calls the
793 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
794
795- The library_version attribute, introduced in an earlier beta, was
796 removed because it can not be supported with early versions of the C
797 readline library, which provides no way to determine the version at
798 compile-time.
799
800- The binascii module is now enabled on Win64.
801
Tim Peters46446d62000-10-09 21:19:31 +0000802- tokenize.py no longer suffers "recursion depth" errors when parsing
803 programs with very long string literals.
804
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000805Internals
806
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000807- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000808 which is called when the interpreter starts up to determine where
809 the standard library is installed. These vulnerabilities affect all
810 previous versions of Python and can be exploited by setting very
811 long values for PYTHONHOME or argv[0]. The risk is greatest for a
812 setuid Python script, although use of the wrapper in
813 Misc/setuid-prog.c will eliminate the vulnerability.
814
815- Fixed garbage collection bugs in instance creation that were
816 triggered when errors occurred during initialization. The solution,
817 applied in cPickle and in PyInstance_New(), is to call
818 PyObject_GC_Init() after the initialization of the object's
819 container attributes is complete.
820
821- pyexpat adds definitions of PyModule_AddStringConstant and
822 PyModule_AddObject if the Python version is less than 2.0, which
823 provides compatibility with PyXML on Python 1.5.2.
824
825- If the platform has a bogus definition for LONG_BIT (the number of
826 bits in a long), an error will be reported at compile time.
827
828- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
829 collection crashes and possibly other, unreported crashes.
830
831- Fixed a memory leak in _PyUnicode_Fini().
832
833Build issues
834
835- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000836 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +0000837 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000838
839- The mmap.PAGESIZE constant is now initialized using sysconf when
840 possible, which eliminates a dependency on -lucb for Reliant UNIX.
841
842- The md5 file should now compile on all platforms.
843
844- The select module now compiles on platforms that do not define
845 POLLRDNORM and related constants.
846
847- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +0000848 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000849
Jeremy Hylton10921202000-10-09 18:34:12 +0000850- BeOS: A number of changes were made to the build and installation
851 process. ar-fake now operates on a directory of object files.
852 dl_export.h is gone, and its macros now appear on the mwcc command
853 line during build on PPC BeOS.
854
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000855- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +0000856 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000857
858- Cygwin: Support for shared libraries, Tkinter, and sockets.
859
860- SunOS 4.1.4_JL: Fix test for directory existence in configure.
861
862Tools and other miscellany
863
864- Removed debugging prints from main used with freeze.
865
Tim Peters46446d62000-10-09 21:19:31 +0000866- IDLE auto-indent no longer crashes when it encounters Unicode
867 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000868
869What's new in 2.0 beta 2 (since beta 1)?
870========================================
871
872Core language, builtins, and interpreter
873
Tim Peters482c0212000-09-26 06:33:09 +0000874- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000875 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +0000876
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000877- Add -h and -V command line options to print the usage message and
878 Python version number and exit immediately.
879
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000880- eval() and exec accept Unicode objects as code parameters.
881
882- getattr() and setattr() now also accept Unicode objects for the
883 attribute name, which are converted to strings using the default
884 encoding before lookup.
885
886- Multiplication on string and Unicode now does proper bounds
887 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
888 string is too long."
889
890- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +0000891 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000892
Jeremy Hylton1b618592000-09-26 05:32:36 +0000893
894Standard library and extensions
895
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000896- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +0000897 argument checking; it still takes no arguments.
898
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000899- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000900
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000901- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000902
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000903- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +0000904
905- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000906 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000907
908- copy: Copy Unicode objects atomically.
909
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000910- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000911
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000912- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000913
Fred Drake67233bc2000-09-26 16:40:27 +0000914- dbm: Add get() and setdefault() methods to dbm object. Add constant
915 `library' to module that names the library used. Added doc strings
916 and method names to error messages. Uses configure to determine
917 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
918 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000919
920- distutils: Update to version 0.9.3.
921
922- dl: Add several dl.RTLD_ constants.
923
924- fpectl: Now supported on FreeBSD.
925
926- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
927 found by the collector will be saved in gc.garbage. This is useful
928 for debugging a program that creates reference cycles.
929
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000930- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +0000931 of HTTP class. Do not close socket on zero-length response. Do not
932 crash when server sends invalid content-length header.
933
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000934- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000935
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000936- marshal: When reading a short, sign-extend on platforms where shorts
937 are bigger than 16 bits. When reading a long, repair the unportable
938 sign extension that was being done for 64-bit machines. (It assumed
939 that signed right shift sign-extends.)
940
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000941- operator: Add contains(), invert(), __invert__() as aliases for
942 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000943
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000944- os: Add support for popen2() and popen3() on all platforms where
945 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +0000946
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000947- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +0000948 clicking on a file in Explorer (or passing the file name to the
949 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +0000950
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000951- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +0000952 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +0000953
954- pickle: Now raises ValueError when an invalid pickle that contains
955 a non-string repr where a string repr was expected. This behavior
956 matches cPickle.
957
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000958- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000959
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000960- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000961
962- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000963 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000964 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +0000965
966- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000967 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000968
969- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +0000970 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +0000971 few cycles during startup since the first call to
972 setdefaultencoding() will initialize the codec registry and the
973 encodings package.
974
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000975- socket: Support for size hint in readlines() method of object returned
976 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +0000977
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000978- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +0000979 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +0000980 is followed by whitespace.
981
Tim Petersa3a3a032000-11-30 05:22:44 +0000982- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000983
984- struct: Check ranges for bytes and shorts.
985
986- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000987 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000988
989- Tkinter: Image objects are now guaranteed to have unique ids. Set
990 event.delta to zero if Tk version doesn't support mousewheel.
991 Removed some debugging prints.
992
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000993- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +0000994
Fred Drake67233bc2000-09-26 16:40:27 +0000995- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000996 which works around a bug in Norton AntiVirus 2000 that leads directly
997 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000998
999- xml: New version detection code allows PyXML to override standard
1000 XML package if PyXML version is greater than 0.6.1.
1001
Fred Drake64bb3802000-09-26 16:21:35 +00001002- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1003 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1004 tree only for nodes which are sufficiently interesting to a specific
1005 application. Does not provide the HTML-specific extensions. Still
1006 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001007
Fred Drake64bb3802000-09-26 16:21:35 +00001008- xml.sax: SAX 2 support for Python, including all the handler
1009 interfaces needed to process XML 1.0 compliant XML. Some
1010 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001011
Fred Drake64bb3802000-09-26 16:21:35 +00001012- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1013 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001014
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001015
Jeremy Hylton1b618592000-09-26 05:32:36 +00001016C API
1017
1018- Add three new convenience functions for module initialization --
1019 PyModule_AddObject(), PyModule_AddIntConstant(), and
1020 PyModule_AddStringConstant().
1021
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001022- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001023 removed and add #error to Python.h if NULL isn't defined after
1024 #include of stdio.h.
1025
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001026- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001027 backwards compatibility (at the source level) with old extensions.
1028
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001029- A wrapper API was added for signal() and sigaction(). Instead of
1030 either function, always use PyOS_getsig() to get a signal handler
1031 and PyOS_setsig() to set one. A new convenience typedef
1032 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001033
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001034- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001035 internal data buffer and size of a string object -- or the default
1036 encoded version of a Unicode object.
1037
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001038- PyString_Size() and PyString_AsString() accept Unicode objects.
1039
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001040- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001041 exists). INT_MAX and LONG_MAX will always be defined, even if
1042 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001043
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001044- PyFloat_FromString takes a second argument, pend, that was
1045 effectively useless. It is now officially useless but preserved for
1046 backwards compatibility. If the pend argument is not NULL, *pend is
1047 set to NULL.
1048
1049- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1050 for the attribute name. See note on getattr() above.
1051
1052- A few bug fixes to argument processing for Unicode.
1053 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1054 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1055 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001056 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001057
1058- Py_BuildValue accepts B format (for bgen-generated code).
1059
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001060
Jeremy Hylton1b618592000-09-26 05:32:36 +00001061Internals
1062
1063- On Unix, fix code for finding Python installation directory so that
1064 it works when argv[0] is a relative path.
1065
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001066- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001067 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001068 rather than by generating a copy of the object.
1069
Tim Peters482c0212000-09-26 06:33:09 +00001070- Several of the internal Unicode tables are much smaller now, and
1071 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001072
Jeremy Hylton97693b02000-09-26 17:42:51 +00001073- In the garbage collector: Fixed bug in collection of tuples. Fixed
1074 bug that caused some instances to be removed from the container set
1075 while they were still live. Fixed parsing in gc.set_debug() for
1076 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001077
1078- Fixed refcount problem in instance deallocation that only occurred
1079 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1080
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001081- On Windows, getpythonregpath is now protected against null data in
1082 registry key.
1083
1084- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001085 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001086
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001087
Jeremy Hylton1b618592000-09-26 05:32:36 +00001088Build and platform-specific issues
1089
1090- Better support of GNU Pth via --with-pth configure option.
1091
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001092- Python/C API now properly exposed to dynamically-loaded extension
1093 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001094
1095- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1096 Don't define MS_SYNC to be zero when it is undefined. Added missing
1097 prototypes in posixmodule.c.
1098
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001099- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001100 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001101
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001102- Fix largefile support on older NetBSD systems and OpenBSD by adding
1103 define for TELL64.
1104
1105
1106Tools and other miscellany
1107
1108- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1109
1110- freeze: The modulefinder now works with 2.0 opcodes.
1111
Tim Petersa3a3a032000-11-30 05:22:44 +00001112- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001113 Move hackery of sys.argv until after the Tk instance has been
1114 created, which allows the application-specific Tkinter
1115 initialization to be executed if present; also pass an explicit
1116 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001117
Jeremy Hylton1b618592000-09-26 05:32:36 +00001118
1119What's new in 2.0 beta 1?
1120=========================
1121
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001122Source Incompatibilities
1123------------------------
1124
1125None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1126such as single-argument append(), connect() and bind(), and changes to
1127str(long) and repr(float).
1128
1129
1130Binary Incompatibilities
1131------------------------
1132
1133- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1134with Python 2.0; these extensions will have to be rebuilt for Python
11352.0.
1136
1137- On Windows, attempting to import a third party extension built for
1138Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1139can do about this. Check your PYTHONPATH environment variable!
1140
1141- Python bytecode files (*.pyc and *.pyo) are not compatible between
1142releases.
1143
1144
1145Overview of Changes Since 1.6
1146-----------------------------
1147
1148There are many new modules (including brand new XML support through
1149the xml package, and i18n support through the gettext module); a list
1150of all new modules is included below. Lots of bugs have been fixed.
1151
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001152The process for making major new changes to the language has changed
1153since Python 1.6. Enhancements must now be documented by a Python
1154Enhancement Proposal (PEP) before they can be accepted.
1155
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001156There are several important syntax enhancements, described in more
1157detail below:
1158
1159 - Augmented assignment, e.g. x += 1
1160
1161 - List comprehensions, e.g. [x**2 for x in range(10)]
1162
1163 - Extended import statement, e.g. import Module as Name
1164
1165 - Extended print statement, e.g. print >> file, "Hello"
1166
1167Other important changes:
1168
1169 - Optional collection of cyclical garbage
1170
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001171Python Enhancement Proposal (PEP)
1172---------------------------------
1173
1174PEP stands for Python Enhancement Proposal. A PEP is a design
1175document providing information to the Python community, or describing
1176a new feature for Python. The PEP should provide a concise technical
1177specification of the feature and a rationale for the feature.
1178
1179We intend PEPs to be the primary mechanisms for proposing new
1180features, for collecting community input on an issue, and for
1181documenting the design decisions that have gone into Python. The PEP
1182author is responsible for building consensus within the community and
1183documenting dissenting opinions.
1184
1185The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001186
1187Augmented Assignment
1188--------------------
1189
1190This must have been the most-requested feature of the past years!
1191Eleven new assignment operators were added:
1192
Guido van Rossume905e952000-09-05 12:42:46 +00001193 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001194
1195For example,
1196
1197 A += B
1198
1199is similar to
1200
1201 A = A + B
1202
1203except that A is evaluated only once (relevant when A is something
1204like dict[index].attr).
1205
1206However, if A is a mutable object, A may be modified in place. Thus,
1207if A is a number or a string, A += B has the same effect as A = A+B
1208(except A is only evaluated once); but if a is a list, A += B has the
1209same effect as A.extend(B)!
1210
1211Classes and built-in object types can override the new operators in
1212order to implement the in-place behavior; the not-in-place behavior is
1213used automatically as a fallback when an object doesn't implement the
1214in-place behavior. For classes, the method name is derived from the
1215method name for the corresponding not-in-place operator by inserting
1216an 'i' in front of the name, e.g. __iadd__ implements in-place
1217__add__.
1218
1219Augmented assignment was implemented by Thomas Wouters.
1220
1221
1222List Comprehensions
1223-------------------
1224
1225This is a flexible new notation for lists whose elements are computed
1226from another list (or lists). The simplest form is:
1227
1228 [<expression> for <variable> in <sequence>]
1229
Guido van Rossum56db0952000-09-06 23:34:25 +00001230For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001231This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001232
1233You can also add a condition:
1234
1235 [<expression> for <variable> in <sequence> if <condition>]
1236
1237For example, [w for w in words if w == w.lower()] would yield the list
1238of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001239than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001240
1241You can also have nested for loops and more than one 'if' clause. For
1242example, here's a function that flattens a sequence of sequences::
1243
1244 def flatten(seq):
1245 return [x for subseq in seq for x in subseq]
1246
1247 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1248
1249This prints
1250
1251 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1252
1253List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001254Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001255
1256
1257Extended Import Statement
1258-------------------------
1259
1260Many people have asked for a way to import a module under a different
1261name. This can be accomplished like this:
1262
1263 import foo
1264 bar = foo
1265 del foo
1266
1267but this common idiom gets old quickly. A simple extension of the
1268import statement now allows this to be written as follows:
1269
1270 import foo as bar
1271
1272There's also a variant for 'from ... import':
1273
1274 from foo import bar as spam
1275
1276This also works with packages; e.g. you can write this:
1277
1278 import test.regrtest as regrtest
1279
1280Note that 'as' is not a new keyword -- it is recognized only in this
1281context (this is only possible because the syntax for the import
1282statement doesn't involve expressions).
1283
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001284Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001285
1286
1287Extended Print Statement
1288------------------------
1289
1290Easily the most controversial new feature, this extension to the print
1291statement adds an option to make the output go to a different file
1292than the default sys.stdout.
1293
1294For example, to write an error message to sys.stderr, you can now
1295write:
1296
1297 print >> sys.stderr, "Error: bad dog!"
1298
1299As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001300evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001301
1302 print >> None, "Hello world"
1303
1304is equivalent to
1305
1306 print "Hello world"
1307
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001308Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001309
1310
1311Optional Collection of Cyclical Garbage
1312---------------------------------------
1313
1314Python is now equipped with a garbage collector that can hunt down
1315cyclical references between Python objects. It's no replacement for
1316reference counting; in fact, it depends on the reference counts being
1317correct, and decides that a set of objects belong to a cycle if all
1318their reference counts can be accounted for from their references to
1319each other. This devious scheme was first proposed by Eric Tiedemann,
1320and brought to implementation by Neil Schemenauer.
1321
1322There's a module "gc" that lets you control some parameters of the
1323garbage collection. There's also an option to the configure script
1324that lets you enable or disable the garbage collection. In 2.0b1,
1325it's on by default, so that we (hopefully) can collect decent user
1326experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001327performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001328off by default in the final 2.0 release.
1329
1330
1331Smaller Changes
1332---------------
1333
1334A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1335map(None, seq1, seq2, ...) when the sequences have the same length;
1336i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1337the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001338zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001339
1340sys.version_info is a tuple (major, minor, micro, level, serial).
1341
1342Dictionaries have an odd new method, setdefault(key, default).
1343dict.setdefault(key, default) returns dict[key] if it exists; if not,
1344it sets dict[key] to default and returns that value. Thus:
1345
1346 dict.setdefault(key, []).append(item)
1347
1348does the same work as this common idiom:
1349
1350 if not dict.has_key(key):
1351 dict[key] = []
1352 dict[key].append(item)
1353
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001354There are two new variants of SyntaxError that are raised for
1355indentation-related errors: IndentationError and TabError.
1356
1357Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1358escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001359
1360The limits on the size of expressions and file in Python source code
1361have been raised from 2**16 to 2**32. Previous versions of Python
1362were limited because the maximum argument size the Python VM accepted
1363was 2**16. This limited the size of object constructor expressions,
1364e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1365limit was raised thanks to a patch by Charles Waldman that effectively
1366fixes the problem. It is now much more likely that you will be
1367limited by available memory than by an arbitrary limit in Python.
1368
1369The interpreter's maximum recursion depth can be modified by Python
1370programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1371limit is the maximum number of recursive calls that can be made by
1372Python code. The limit exists to prevent infinite recursion from
1373overflowing the C stack and causing a core dump. The default value is
13741000. The maximum safe value for a particular platform can be found
1375by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001376
1377New Modules and Packages
1378------------------------
1379
1380atexit - for registering functions to be called when Python exits.
1381
1382imputil - Greg Stein's alternative API for writing custom import
1383hooks.
1384
1385pyexpat - an interface to the Expat XML parser, contributed by Paul
1386Prescod.
1387
1388xml - a new package with XML support code organized (so far) in three
1389subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1390would fill a volume. There's a special feature whereby a
1391user-installed package named _xmlplus overrides the standard
1392xmlpackage; this is intended to give the XML SIG a hook to distribute
1393backwards-compatible updates to the standard xml package.
1394
1395webbrowser - a platform-independent API to launch a web browser.
1396
1397
Guido van Rossume905e952000-09-05 12:42:46 +00001398Changed Modules
1399---------------
1400
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001401array -- new methods for array objects: count, extend, index, pop, and
1402remove
1403
1404binascii -- new functions b2a_hex and a2b_hex that convert between
1405binary data and its hex representation
1406
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001407calendar -- Many new functions that support features including control
1408over which day of the week is the first day, returning strings instead
1409of printing them. Also new symbolic constants for days of week,
1410e.g. MONDAY, ..., SUNDAY.
1411
1412cgi -- FieldStorage objects have a getvalue method that works like a
1413dictionary's get method and returns the value attribute of the object.
1414
1415ConfigParser -- The parser object has new methods has_option,
1416remove_section, remove_option, set, and write. They allow the module
1417to be used for writing config files as well as reading them.
1418
1419ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001420optionally support the RFC 959 REST command.
1421
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001422gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001423
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001424httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1425the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001426
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001427locale -- implement getdefaultlocale for Win32 and Macintosh
1428
1429marshal -- no longer dumps core when marshaling deeply nested or
1430recursive data structures
1431
1432os -- new functions isatty, seteuid, setegid, setreuid, setregid
1433
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001434os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1435support under Unix.
1436
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001437os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001438
1439os.path -- fix semantics of os.path.commonprefix
1440
1441smtplib -- support for sending very long messages
1442
1443socket -- new function getfqdn()
1444
1445readline -- new functions to read, write and truncate history files.
1446The readline section of the library reference manual contains an
1447example.
1448
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001449select -- add interface to poll system call
1450
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001451shutil -- new copyfileobj function
1452
1453SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1454HTTP server.
1455
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001456Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001457
1458urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001459e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001460
1461whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001462
1463
1464Obsolete Modules
1465----------------
1466
1467None. However note that 1.6 made a whole slew of modules obsolete:
1468stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1469poly, zmod, strop, util, whatsound.
1470
1471
1472Changed, New, Obsolete Tools
1473----------------------------
1474
Tim Peters8b092332000-09-05 20:15:25 +00001475None.
Guido van Rossume905e952000-09-05 12:42:46 +00001476
1477
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001478C-level Changes
1479---------------
1480
1481Several cleanup jobs were carried out throughout the source code.
1482
1483All C code was converted to ANSI C; we got rid of all uses of the
1484Py_PROTO() macro, which makes the header files a lot more readable.
1485
1486Most of the portability hacks were moved to a new header file,
1487pyport.h; several other new header files were added and some old
1488header files were removed, in an attempt to create a more rational set
1489of header files. (Few of these ever need to be included explicitly;
1490they are all included by Python.h.)
1491
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001492Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001493and Win64, especially for the new Intel Itanium processor. Mick also
1494added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001495
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001496The C APIs to return an object's size have been update to consistently
1497use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1498previous versions, the abstract interfaces used PyXXX_Length and the
1499concrete interfaces used PyXXX_Size. The old names,
1500e.g. PyObject_Length, are still available for backwards compatibility
1501at the API level, but are deprecated.
1502
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001503The PyOS_CheckStack function has been implemented on Windows by
1504Fredrik Lundh. It prevents Python from failing with a stack overflow
1505on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001506
1507The GC changes resulted in creation of two new slots on object,
1508tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001509the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001510
1511The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001512C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001513
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001514PyErr_Format has been updated to automatically calculate the size of
1515the buffer needed to hold the formatted result string. This change
1516prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001517
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001518New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001519
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001520PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1521that are the same as their non-Ex counterparts except they take an
1522extra flag argument that tells them to close the file when done.
1523
1524XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001525
Tim Peters8b092332000-09-05 20:15:25 +00001526
1527Windows Changes
1528---------------
1529
1530New popen2/popen3/peopen4 in os module (see Changed Modules above).
1531
1532os.popen is much more usable on Windows 95 and 98. See Microsoft
1533Knowledge Base article Q150956. The Win9x workaround described there
1534is implemented by the new w9xpopen.exe helper in the root of your
1535Python installation. Note that Python uses this internally; it is not
1536a standalone program.
1537
1538Administrator privileges are no longer required to install Python
1539on Windows NT or Windows 2000. If you have administrator privileges,
1540Python's registry info will be written under HKEY_LOCAL_MACHINE.
1541Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001542under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001543uses of Python, but will prevent some advanced uses from working
1544(for example, running a Python script as an NT service, or possibly
1545from CGI).
1546
1547[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1548installer; instead, it installs the needed Tcl/Tk files directly in the
1549Python directory. If you already have a Tcl/Tk installation, this
1550wastes some disk space (about 4 Megs) but avoids problems with
1551conflicting Tcl/Tk installations, and makes it much easier for Python
1552to ensure that Tcl/Tk can find all its files.
1553
1554[This was new in 1.6] The Windows installer now installs by default in
1555\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1556
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001557
1558Updates to the changes between 1.5.2 and 1.6
1559--------------------------------------------
1560
1561The 1.6 NEWS file can't be changed after the release is done, so here
1562is some late-breaking news:
1563
1564New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1565and changes to getlocale() and setlocale().
1566
1567The new module is now enabled per default.
1568
1569It is not true that the encodings codecs cannot be used for normal
1570strings: the string.encode() (which is also present on 8-bit strings
1571!) allows using them for 8-bit strings too, e.g. to convert files from
1572cp1252 (Windows) to latin-1 or vice-versa.
1573
1574Japanese codecs are available from Tamito KAJIYAMA:
1575http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1576
1577
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001578======================================================================