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Tim Petersd66595f2001-02-04 03:09:53 +00001What's New in Python 2.1 alpha 507?
2===================================
3
4Core language, builtins, and interpreter
5
Neil Schemenauera35c6882001-02-27 04:45:05 +00006- An optional object allocator has been included. This allocator is
7 optimized for Python objects and should be faster and use less memory
8 than the standard system allocator. It is not enabled by default
9 because of possible thread safety problems. The allocator is only
10 protected by the Python interpreter lock and it is possible that some
11 extension modules require a thread safe allocator. The object
12 allocator can be enabled by providing the "--with-pymalloc" option to
13 configure.
14
Tim Petersd66595f2001-02-04 03:09:53 +000015Standard library
16
Martin v. Löwis2a5130e2001-02-27 04:21:58 +000017- pyexpat now detects the expat version if expat.h defines it. A
18 number of additional handlers are provided, which are only available
19 since expat 1.95. In addition, the methods SetParamEntityParsing and
20 GetInputContext of Parser objects are available with 1.95.x
21 only. Parser objects now provide the ordered_attributes and
22 specified_attributes attributes. A new module expat.model was added,
23 which offers a number of additional constants if 1.95.x is used.
24
25- xml.dom offers the new functions registerDOMImplementation and
26 getDOMImplementation.
27
28- xml.dom.minidom offers a toprettyxml method. A number of DOM
29 conformance issues have been resolved. In particular, Element now
30 has an hasAttributes method, and the handling of namespaces was
31 improved.
32
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +000033- Ka-Ping Yee contributed two new modules: inspect.py, a module for
34 getting information about live Python code, and pydoc.py, a module
35 for interactively converting docstrings to HTML or text.
36 Tools/scripts/pydoc, which is now automatically installed into
37 <prefix>/bin, uses pydoc.py to display documentation; try running
38 'pydoc' for the instructions.
39
Tim Petersd66595f2001-02-04 03:09:53 +000040Windows changes
41
42- Build: Subproject _test (effectively) renamed to _testcapi.
43
Tim Peters25a9ce32001-02-19 07:06:36 +000044- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
45 what it's supposed to do (and does do under NT and 2000) via direct
46 port manipulation. It's unknown whether this will work on all systems,
47 but it does work on my Win98SE system now and was known to be useless on
48 all Win9x systems before.
49
50
Tim Petersd7b5e882001-01-25 03:36:26 +000051What's New in Python 2.1 alpha 2?
52=================================
Tim Peters40ead762001-01-27 05:35:26 +000053
Tim Petersd7b5e882001-01-25 03:36:26 +000054Core language, builtins, and interpreter
55
Jeremy Hylton4589bd82001-02-01 20:38:45 +000056- Scopes nest. If a name is used in a function or class, but is not
57 local, the definition in the nearest enclosing function scope will
58 be used. One consequence of this change is that lambda statements
59 could reference variables in the namespaces where the lambda is
60 defined. In some unusual cases, this change will break code.
61
62 In all previous version of Python, names were resolved in exactly
63 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +000064 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +000065 function A is defined within a function B, the names bound in B are
66 not visible in A. The new rules make names bound in B visible in A,
67 unless A contains a name binding that hides the binding in B.
68
69 Section 4.1 of the reference manual describes the new scoping rules
70 in detail. The test script in Lib/test/test_scope.py demonstrates
71 some of the effects of the change.
72
73 The new rules will cause existing code to break if it defines nested
74 functions where an outer function has local variables with the same
75 name as globals or builtins used by the inner function. Example:
76
77 def munge(str):
78 def helper(x):
79 return str(x)
80 if type(str) != type(''):
81 str = helper(str)
82 return str.strip()
83
84 Under the old rules, the name str in helper() is bound to the
85 builtin function str(). Under the new rules, it will be bound to
86 the argument named str and an error will occur when helper() is
87 called.
88
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +000089- The compiler will report a SyntaxError if "from ... import *" occurs
90 in a function or class scope. The language reference has documented
91 that this case is illegal, but the compiler never checked for it.
92 The recent introduction of nested scope makes the meaning of this
93 form of name binding ambiguous. In a future release, the compiler
94 may allow this form when there is no possibility of ambiguity.
95
Tim Peters40ead762001-01-27 05:35:26 +000096- repr(string) is easier to read, now using hex escapes instead of octal,
97 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
98
99 >>> "\texample \r\n" + chr(0) + chr(255)
100 '\texample \r\n\x00\xff' # in 2.1
101 '\011example \015\012\000\377' # in 2.0
102
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000103- Functions are now compared and hashed by identity, not by value, since
104 the func_code attribute is writable.
105
Fred Drakefb9d7122001-02-01 20:00:40 +0000106- Weak references (PEP 205) have been added. This involves a few
107 changes in the core, an extension module (_weakref), and a Python
108 module (weakref). The weakref module is the public interface. It
109 includes support for "explicit" weak references, proxy objects, and
110 mappings with weakly held values.
111
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000112- A 'continue' statement can now appear in a try block within the body
113 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000114 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000115
Tim Petersd7b5e882001-01-25 03:36:26 +0000116Standard library
117
Barry Warsaw30dbd142001-01-31 22:14:01 +0000118- mailbox.py now has a new class, PortableUnixMailbox which is
119 identical to UnixMailbox but uses a more portable scheme for
120 determining From_ separators. Also, the constructors for all the
121 classes in this module have a new optional `factory' argument, which
122 is a callable used when new message classes must be instantiated by
123 the next() method.
124
Tim Petersd7b5e882001-01-25 03:36:26 +0000125- random.py is now self-contained, and offers all the functionality of
126 the now-deprecated whrandom.py. See the docs for details. random.py
127 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000128 and restoring the internal state of the generator; and jumpahead(n),
129 for quickly forcing the internal state to be the same as if n calls to
130 random() had been made. The latter is particularly useful for multi-
131 threaded programs, creating one instance of the random.Random() class for
132 each thread, then using .jumpahead() to force each instance to use a
133 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000134
Tim Peters0de88fc2001-02-01 04:59:18 +0000135- random.py's seed() function is new. For bit-for-bit compatibility with
136 prior releases, use the whseed function instead. The new seed function
137 addresses two problems: (1) The old function couldn't produce more than
138 about 2**24 distinct internal states; the new one about 2**45 (the best
139 that can be done in the Wichmann-Hill generator). (2) The old function
140 sometimes produced identical internal states when passed distinct
141 integers, and there was no simple way to predict when that would happen;
142 the new one guarantees to produce distinct internal states for all
143 arguments in [0, 27814431486576L).
144
Jeremy Hylton4c4fda02001-02-02 03:29:24 +0000145- The socket module now supports raw packets on Linux. The socket
146 family is AF_PACKET.
147
Tim Peters9ea17ac2001-02-02 05:57:15 +0000148- test_capi.py is a start at running tests of the Python C API. The tests
149 are implemented by the new Modules/_testmodule.c.
150
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000151- A new extension module, _symtable, provides provisional access to the
152 internal symbol table used by the Python compiler. A higher-level
153 interface will be added on top of _symtable in a future release.
154
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +0000155- Removed the obsolete soundex module.
156
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000157- xml.dom.minidom now uses the standard DOM exceptions. Node supports
158 the isSameNode method; NamedNodeMap the get method.
159
160- xml.sax.expatreader supports the lexical handler property; it
161 generates comment, startCDATA, and endCDATA events.
162
Tim Petersee826f82001-01-31 19:39:44 +0000163Windows changes
164
165- Build procedure: the zlib project is built in a different way that
166 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +0000167 the zlib binary used. See PCbuild\readme.txt for details. Your old
168 zlib-related directories can be deleted; you'll need to download fresh
169 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +0000170
Tim Peters9ea17ac2001-02-02 05:57:15 +0000171- Build: New subproject _test for the benefit of test_capi.py (see above).
172
Tim Petersb16c56f2001-02-02 21:24:51 +0000173- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
174 interface to some Python compiler internals).
175
176- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +0000177 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +0000178
Tim Petersa3a3a032000-11-30 05:22:44 +0000179What's New in Python 2.1 alpha 1?
180=================================
181
182Core language, builtins, and interpreter
183
Marc-André Lemburgebb195b2001-01-20 10:34:52 +0000184- There is a new Unicode companion to the PyObject_Str() API
185 called PyObject_Unicode(). It behaves in the same way as the
186 former, but assures that the returned value is an Unicode object
187 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +0000188
Guido van Rossumf98eda02001-01-17 15:54:45 +0000189- The comparison operators support "rich comparison overloading" (PEP
190 207). C extension types can provide a rich comparison function in
191 the new tp_richcompare slot in the type object. The cmp() function
192 and the C function PyObject_Compare() first try the new rich
193 comparison operators before trying the old 3-way comparison. There
194 is also a new C API PyObject_RichCompare() (which also falls back on
195 the old 3-way comparison, but does not constrain the outcome of the
196 rich comparison to a Boolean result).
197
198 The rich comparison function takes two objects (at least one of
199 which is guaranteed to have the type that provided the function) and
200 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
201 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
202 object, which may be NotImplemented (in which case the tp_compare
203 slot function is used as a fallback, if defined).
204
205 Classes can overload individual comparison operators by defining one
206 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +0000207 __ge__. There are no explicit "reflected argument" versions of
208 these; instead, __lt__ and __gt__ are each other's reflection,
209 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
210 reflection (similar at the C level). No other implications are
211 made; in particular, Python does not assume that == is the Boolean
212 inverse of !=, or that < is the Boolean inverse of >=. This makes
213 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +0000214
215 Classes or types that want to implement (in)equality tests but not
216 the ordering operators (i.e. unordered types) should implement ==
217 and !=, and raise an error for the ordering operators.
218
Guido van Rossuma88479f2001-01-18 14:28:08 +0000219 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +0000220 Boolean; e.g. a matrix type might want to return a matrix of bits
221 for A < B, giving elementwise comparisons. Such types should ensure
222 that any interpretation of their value in a Boolean context raises
223 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
224 at the C level) to always raise an exception.
225
Guido van Rossuma88479f2001-01-18 14:28:08 +0000226- Complex numbers use rich comparisons to define == and != but raise
227 an exception for <, <=, > and >=. Unfortunately, this also means
228 that cmp() of two complex numbers raises an exception when the two
229 numbers differ. Since it is not mathematically meaningful to compare
230 complex numbers except for equality, I hope that this doesn't break
231 too much code.
232
Tim Peters3389f192001-02-18 08:48:49 +0000233- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +0000234 not defined by the language, other than that it's arbitrary but
235 consistent (see the Reference Manual). An implementation detail changed
236 in 2.1a1 such that None now compares less than any other object. Code
237 relying on this new behavior (like code that relied on the previous
238 behavior) does so at its own risk.
239
Barry Warsaw573b5412001-01-15 20:43:18 +0000240- Functions and methods now support getting and setting arbitrarily
241 named attributes (PEP 232). Functions have a new __dict__
242 (a.k.a. func_dict) which hold the function attributes. Methods get
243 and set attributes on their underlying im_func. It is a TypeError
244 to set an attribute on a bound method.
245
Guido van Rossum051e3352001-01-15 19:11:10 +0000246- The xrange() object implementation has been improved so that
247 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
248 limitation that in this case len(xrange(sys.maxint)) can't be
249 calculated, but the common idiom "for i in xrange(sys.maxint)" will
250 work fine as long as the index i doesn't actually reach 2**31.
251 (Python uses regular ints for sequence and string indices; fixing
252 that is much more work.)
253
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000254- Two changes to from...import:
255
Guido van Rossumba381232001-02-03 15:06:40 +0000256 1) "from M import X" now works even if (after loading module M)
257 sys.modules['M'] is not a real module; it's basically a getattr()
258 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +0000259
260 2) "from M import *" now looks for M.__all__ to decide which names to
261 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
262 filters out names starting with '_' as before. Whether or not
263 __all__ exists, there's no restriction on the type of M.
264
Guido van Rossumf61f1662001-01-10 20:13:55 +0000265- File objects have a new method, xreadlines(). This is the fastest
266 way to iterate over all lines in a file:
267
268 for line in file.xreadlines():
269 ...do something to line...
270
271 See the xreadlines module (mentioned below) for how to do this for
272 other file-like objects.
273
274- Even if you don't use file.xreadlines(), you may expect a speedup on
275 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +0000276 quite a bit in platform-specific ways: on systems (like Linux) that
277 support flockfile(), getc_unlocked(), and funlockfile(), those are
278 used by default. On systems (like Windows) without getc_unlocked(),
279 a complicated (but still thread-safe) method using fgets() is used by
280 default.
281
Tim Petersd52269b2001-01-25 06:23:18 +0000282 You can force use of the fgets() method by #define'ing
283 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +0000284 getc_unlocked()).
285
Tim Petersd52269b2001-01-25 06:23:18 +0000286 You can force fgets() not to be used by #define'ing
287 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +0000288 test_bufio.py fails -- and let us know if it does!).
289
290- In addition, the fileinput module, while still slower than the other
291 methods on most platforms, has been sped up too, by using
292 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000293
294- Support for run-time warnings has been added, including a new
295 command line option (-W) to specify the disposition of warnings.
296 See the description of the warnings module below.
297
298- Extensive changes have been made to the coercion code. This mostly
299 affects extension modules (which can now implement mixed-type
300 numerical operators without having to use coercion), but
301 occasionally, in boundary cases the coercion semantics have changed
302 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +0000303 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +0000304 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +0000305 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +0000306
Guido van Rossumf98eda02001-01-17 15:54:45 +0000307- In connection with the coercion changes, a new built-in singleton
308 object, NotImplemented is defined. This can be returned for
309 operations that wish to indicate they are not implemented for a
310 particular combination of arguments. From C, this is
311 Py_NotImplemented.
312
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000313- The interpreter accepts now bytecode files on the command line even
314 if they do not have a .pyc or .pyo extension. On Linux, after executing
315
Martin v. Löwise214baa2001-02-04 22:37:56 +0000316import imp,sys,string
317magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
318reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
319open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +0000320
321 any byte code file can be used as an executable (i.e. as an argument
322 to execve(2)).
323
Tim Peters9940b802000-12-01 07:59:35 +0000324- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +0000325 character. In 1.6 and earlier, they never produced a sign,
326 and raised an error if the value of the long was too large
327 to fit in a Python int. In 2.0, they produced a sign if and
328 only if too large to fit in an int. This was inconsistent
329 across platforms (because the size of an int varies across
330 platforms), and inconsistent with hex() and oct(). Example:
331
332 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +0000333 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +0000334 'ffffffbe' # in 2.0 and before, on 32-bit machines
335 >>> hex(-0x42L)
336 '-0x42L' # in all versions of Python
337
Tim Peters9940b802000-12-01 07:59:35 +0000338 The behavior of %d formats for negative Python longs remains
339 the same as in 2.0 (although in 1.6 and before, they raised
340 an error if the long didn't fit in a Python int).
341
342 %u formats don't make sense for Python longs, but are allowed
343 and treated the same as %d in 2.1. In 2.0, a negative long
344 formatted via %u produced a sign if and only if too large to
345 fit in an int. In 1.6 and earlier, a negative long formatted
346 via %u raised an error if it was too big to fit in an int.
347
Guido van Rossum3661d392000-12-12 22:10:31 +0000348- Dictionary objects have an odd new method, popitem(). This removes
349 an arbitrary item from the dictionary and returns it (in the form of
350 a (key, value) pair). This can be useful for algorithms that use a
351 dictionary as a bag of "to do" items and repeatedly need to pick one
352 item. Such algorithms normally end up running in quadratic time;
353 using popitem() they can usually be made to run in linear time.
354
Tim Peters36cdad12000-12-29 02:06:45 +0000355Standard library
356
Thomas Woutersfe385252001-01-19 23:16:56 +0000357- In the time module, the time argument to the functions strftime,
358 localtime, gmtime, asctime and ctime is now optional, defaulting to
359 the current time (in the local timezone).
360
Guido van Rossumda91f222001-01-15 16:36:08 +0000361- The ftplib module now defaults to passive mode, which is deemed a
362 more useful default given that clients are often inside firewalls
363 these days. Note that this could break if ftplib is used to connect
364 to a *server* that is inside a firewall, from outside; this is
365 expected to be a very rare situation. To fix that, you can call
366 ftp.set_pasv(0).
367
Martin v. Löwis10a27872001-01-13 09:54:41 +0000368- The module site now treats .pth files not only for path configuration,
369 but also supports extensions to the initialization code: Lines starting
370 with import are executed.
371
Guido van Rossumf61f1662001-01-10 20:13:55 +0000372- There's a new module, warnings, which implements a mechanism for
373 issuing and filtering warnings. There are some new built-in
374 exceptions that serve as warning categories, and a new command line
375 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
376 turns warnings into errors). warnings.warn(message[, category])
377 issues a warning message; this can also be called from C as
378 PyErr_Warn(category, message).
379
380- A new module xreadlines was added. This exports a single factory
381 function, xreadlines(). The intention is that this code is the
382 absolutely fastest way to iterate over all lines in an open
383 file(-like) object:
384
385 import xreadlines
386 for line in xreadlines.xreadlines(file):
387 ...do something to line...
388
389 This is equivalent to the previous the speed record holder using
390 file.readlines(sizehint). Note that if file is a real file object
391 (as opposed to a file-like object), this is equivalent:
392
393 for line in file.xreadlines():
394 ...do something to line...
395
Tim Peters36cdad12000-12-29 02:06:45 +0000396- The bisect module has new functions bisect_left, insort_left,
397 bisect_right and insort_right. The old names bisect and insort
398 are now aliases for bisect_right and insort_right. XXX_right
399 and XXX_left methods differ in what happens when the new element
400 compares equal to one or more elements already in the list: the
401 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +0000402 right. Code that doesn't care where equal elements end up should
403 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +0000404
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +0000405- The new curses.panel module wraps the panel library that forms part
406 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
407
Guido van Rossumf61f1662001-01-10 20:13:55 +0000408- The SocketServer module now sets the allow_reuse_address flag by
409 default in the TCPServer class.
410
411- A new function, sys._getframe(), returns the stack frame pointer of
412 the caller. This is intended only as a building block for
413 higher-level mechanisms such as string interpolation.
414
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000415- The pyexpat module supports a number of new handlers, which are
416 available only in expat 1.2. If invocation of a callback fails, it
417 will report an additional frame in the traceback. Parser objects
418 participate now in garbage collection. If expat reports an unknown
419 encoding, pyexpat will try to use a Python codec; that works only
420 for single-byte charsets. The parser type objects is exposed as
421 XMLParserObject.
422
423- xml.dom now offers standard definitions for symbolic node type and
424 exception code constants, and a hierarchy of DOM exceptions. minidom
425 was adjusted to use them.
426
427- The conformance of xml.dom.minidom to the DOM specification was
428 improved. It detects a number of additional error cases; the
429 previous/next relationship works even when the tree is modified;
430 Node supports the normalize() method; NamedNodeMap, DocumentType and
431 DOMImplementation classes were added; Element supports the
432 hasAttribute and hasAttributeNS methods; and Text supports the splitText
433 method.
434
Guido van Rossumf61f1662001-01-10 20:13:55 +0000435Build issues
436
Guido van Rossum1e33bdc2001-01-23 03:17:00 +0000437- For Unix (and Unix-compatible) builds, configuration and building of
438 extension modules is now greatly automated. Rather than having to
439 edit the Modules/Setup file to indicate which modules should be
440 built and where their include files and libraries are, a
441 distutils-based setup.py script now takes care of building most
442 extension modules. All extension modules built this way are built
443 as shared libraries. Only a few modules that must be linked
444 statically are still listed in the Setup file; you won't need to
445 edit their configuration.
446
447- Python should now build out of the box on Cygwin. If it doesn't,
448 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +0000449
450- Python now always uses its own (renamed) implementation of getopt()
451 -- there's too much variation among C library getopt()
452 implementations.
453
454- C++ compilers are better supported; the CXX macro is always set to a
455 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +0000456
Tim Petersd92dfe02000-12-12 01:18:41 +0000457Windows changes
458
459- select module: By default under Windows, a select() call
460 can specify no more than 64 sockets. Python now boosts
461 this Microsoft default to 512. If you need even more than
462 that, see the MS docs (you'll need to #define FD_SETSIZE
463 and recompile Python from source).
464
Guido van Rossumf61f1662001-01-10 20:13:55 +0000465- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
466 subdirectory is no more!
467
Tim Petersa3a3a032000-11-30 05:22:44 +0000468
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000469What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +0000470=========================
Guido van Rossum61000331997-08-15 04:39:58 +0000471
Guido van Rossum8ed602b2000-09-01 22:34:33 +0000472Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000473changes are in the file HISTORY. If you are making the jump directly
474from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
475HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +0000476
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000477Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
478the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
479http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +0000480
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000481--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +0000482
483======================================================================
484
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000485What's new in 2.0 (since release candidate 1)?
486==============================================
487
488Standard library
489
490- The copy_reg module was modified to clarify its intended use: to
491 register pickle support for extension types, not for classes.
492 pickle() will raise a TypeError if it is passed a class.
493
494- Fixed a bug in gettext's "normalize and expand" code that prevented
495 it from finding an existing .mo file.
496
497- Restored support for HTTP/0.9 servers in httplib.
498
Tim Peters989b7b92000-10-16 20:24:53 +0000499- The math module was changed to stop raising OverflowError in case of
500 underflow, and return 0 instead in underflow cases. Whether Python
501 used to raise OverflowError in case of underflow was platform-
502 dependent (it did when the platform math library set errno to ERANGE
503 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000504
505- Fixed a bug in StringIO that occurred when the file position was not
506 at the end of the file and write() was called with enough data to
507 extend past the end of the file.
508
509- Fixed a bug that caused Tkinter error messages to get lost on
510 Windows. The bug was fixed by replacing direct use of
511 interp->result with Tcl_GetStringResult(interp).
512
513- Fixed bug in urllib2 that caused it to fail when it received an HTTP
514 redirect response.
515
516- Several changes were made to distutils: Some debugging code was
517 removed from util. Fixed the installer used when an external zip
518 program (like WinZip) is not found; the source code for this
519 installer is in Misc/distutils. check_lib() was modified to behave
520 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
521 test for whether installed modules are on sys.path was changed to
522 use both normcase() and normpath().
523
Jeremy Hyltond867a2c2000-10-16 20:41:38 +0000524- Several minor bugs were fixed in the xml package (the minidom,
525 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000526
527- The regression test driver (regrtest.py) behavior when invoked with
528 -l changed: It now reports a count of objects that are recognized as
529 garbage but not freed by the garbage collector.
530
Tim Peters989b7b92000-10-16 20:24:53 +0000531- The regression test for the math module was changed to test
532 exceptional behavior when the test is run in verbose mode. Python
533 cannot yet guarantee consistent exception behavior across platforms,
534 so the exception part of test_math is run only in verbose mode, and
535 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000536
537Internals
538
539- PyOS_CheckStack() has been disabled on Win64, where it caused
540 test_sre to fail.
541
542Build issues
543
544- Changed compiler flags, so that gcc is always invoked with -Wall and
545 -Wstrict-prototypes. Users compiling Python with GCC should see
546 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +0000547 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +0000548 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000549
Tim Petersa3a3a032000-11-30 05:22:44 +0000550- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000551
552Tools and other miscellany
553
554- The compiler in Tools/compiler was updated to support the new
555 language features introduced in 2.0: extended print statement, list
556 comprehensions, and augmented assignments. The new compiler should
557 also be backwards compatible with Python 1.5.2; the compiler will
558 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +0000559 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000560
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000561What's new in 2.0 release candidate 1 (since beta 2)?
562=====================================================
563
Jeremy Hylton6040aaa2000-10-09 21:27:22 +0000564What is release candidate 1?
565
566We believe that release candidate 1 will fix all known bugs that we
567intend to fix for the 2.0 final release. This release should be a bit
568more stable than the previous betas. We would like to see even more
569widespread testing before the final release, so we are producing this
570release candidate. The final release will be exactly the same unless
571any show-stopping (or brown bag) bugs are found by testers of the
572release candidate.
573
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000574All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000575to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000576
577Core language, builtins, and interpreter
578
579- A bug that caused crashes when __coerce__ was used with augmented
580 assignment, e.g. +=, was fixed.
581
582- Raise ZeroDivisionError when raising zero to a negative number,
583 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
584 power operator and the result of math.pow(0.0, -2.0) will vary by
585 platform. On Linux, it raises a ValueError.
586
587- A bug in Unicode string interpolation was fixed that occasionally
588 caused errors with formats including "%%". For example, the
589 following expression "%% %s" % u"abc" no longer raises a TypeError.
590
591- Compilation of deeply nested expressions raises MemoryError instead
592 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
593
594- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
595 rendering them useless. They are now written in binary mode again.
596
597Standard library
598
599- Keyword arguments are now accepted for most pattern and match object
600 methods in SRE, the standard regular expression engine.
601
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000602- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +0000603 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000604
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000605- Several bugs in the Unicode handling and error handling in _tkinter
606 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000607
608- Fix memory management errors in Merge() and Tkapp_Call() routines.
609
610- Several changes were made to cStringIO to make it compatible with
611 the file-like object interface and with StringIO. If operations are
612 performed on a closed object, an exception is raised. The truncate
613 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +0000614 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000615
616- There were many changes made to the linuxaudiodev module and its
617 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +0000618 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000619
620 Note that this module is named poorly, because it should work
621 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +0000622 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000623
624 The module now raises exceptions when errors occur instead of
625 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
626 audio) and defines a getptr() method that calls the
627 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
628
629- The library_version attribute, introduced in an earlier beta, was
630 removed because it can not be supported with early versions of the C
631 readline library, which provides no way to determine the version at
632 compile-time.
633
634- The binascii module is now enabled on Win64.
635
Tim Peters46446d62000-10-09 21:19:31 +0000636- tokenize.py no longer suffers "recursion depth" errors when parsing
637 programs with very long string literals.
638
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000639Internals
640
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000641- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000642 which is called when the interpreter starts up to determine where
643 the standard library is installed. These vulnerabilities affect all
644 previous versions of Python and can be exploited by setting very
645 long values for PYTHONHOME or argv[0]. The risk is greatest for a
646 setuid Python script, although use of the wrapper in
647 Misc/setuid-prog.c will eliminate the vulnerability.
648
649- Fixed garbage collection bugs in instance creation that were
650 triggered when errors occurred during initialization. The solution,
651 applied in cPickle and in PyInstance_New(), is to call
652 PyObject_GC_Init() after the initialization of the object's
653 container attributes is complete.
654
655- pyexpat adds definitions of PyModule_AddStringConstant and
656 PyModule_AddObject if the Python version is less than 2.0, which
657 provides compatibility with PyXML on Python 1.5.2.
658
659- If the platform has a bogus definition for LONG_BIT (the number of
660 bits in a long), an error will be reported at compile time.
661
662- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
663 collection crashes and possibly other, unreported crashes.
664
665- Fixed a memory leak in _PyUnicode_Fini().
666
667Build issues
668
669- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000670 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +0000671 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000672
673- The mmap.PAGESIZE constant is now initialized using sysconf when
674 possible, which eliminates a dependency on -lucb for Reliant UNIX.
675
676- The md5 file should now compile on all platforms.
677
678- The select module now compiles on platforms that do not define
679 POLLRDNORM and related constants.
680
681- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +0000682 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000683
Jeremy Hylton10921202000-10-09 18:34:12 +0000684- BeOS: A number of changes were made to the build and installation
685 process. ar-fake now operates on a directory of object files.
686 dl_export.h is gone, and its macros now appear on the mwcc command
687 line during build on PPC BeOS.
688
Jeremy Hyltond6e20232000-10-16 20:08:38 +0000689- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +0000690 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +0000691
692- Cygwin: Support for shared libraries, Tkinter, and sockets.
693
694- SunOS 4.1.4_JL: Fix test for directory existence in configure.
695
696Tools and other miscellany
697
698- Removed debugging prints from main used with freeze.
699
Tim Peters46446d62000-10-09 21:19:31 +0000700- IDLE auto-indent no longer crashes when it encounters Unicode
701 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000702
703What's new in 2.0 beta 2 (since beta 1)?
704========================================
705
706Core language, builtins, and interpreter
707
Tim Peters482c0212000-09-26 06:33:09 +0000708- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000709 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +0000710
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000711- Add -h and -V command line options to print the usage message and
712 Python version number and exit immediately.
713
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000714- eval() and exec accept Unicode objects as code parameters.
715
716- getattr() and setattr() now also accept Unicode objects for the
717 attribute name, which are converted to strings using the default
718 encoding before lookup.
719
720- Multiplication on string and Unicode now does proper bounds
721 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
722 string is too long."
723
724- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +0000725 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000726
Jeremy Hylton1b618592000-09-26 05:32:36 +0000727
728Standard library and extensions
729
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000730- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +0000731 argument checking; it still takes no arguments.
732
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000733- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000734
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000735- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000736
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000737- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +0000738
739- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000740 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000741
742- copy: Copy Unicode objects atomically.
743
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000744- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000745
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000746- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000747
Fred Drake67233bc2000-09-26 16:40:27 +0000748- dbm: Add get() and setdefault() methods to dbm object. Add constant
749 `library' to module that names the library used. Added doc strings
750 and method names to error messages. Uses configure to determine
751 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
752 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000753
754- distutils: Update to version 0.9.3.
755
756- dl: Add several dl.RTLD_ constants.
757
758- fpectl: Now supported on FreeBSD.
759
760- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
761 found by the collector will be saved in gc.garbage. This is useful
762 for debugging a program that creates reference cycles.
763
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000764- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +0000765 of HTTP class. Do not close socket on zero-length response. Do not
766 crash when server sends invalid content-length header.
767
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000768- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000769
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000770- marshal: When reading a short, sign-extend on platforms where shorts
771 are bigger than 16 bits. When reading a long, repair the unportable
772 sign extension that was being done for 64-bit machines. (It assumed
773 that signed right shift sign-extends.)
774
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000775- operator: Add contains(), invert(), __invert__() as aliases for
776 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000777
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000778- os: Add support for popen2() and popen3() on all platforms where
779 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +0000780
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000781- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +0000782 clicking on a file in Explorer (or passing the file name to the
783 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +0000784
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000785- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +0000786 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +0000787
788- pickle: Now raises ValueError when an invalid pickle that contains
789 a non-string repr where a string repr was expected. This behavior
790 matches cPickle.
791
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000792- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000793
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000794- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000795
796- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000797 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000798 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +0000799
800- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000801 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000802
803- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +0000804 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +0000805 few cycles during startup since the first call to
806 setdefaultencoding() will initialize the codec registry and the
807 encodings package.
808
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000809- socket: Support for size hint in readlines() method of object returned
810 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +0000811
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000812- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +0000813 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +0000814 is followed by whitespace.
815
Tim Petersa3a3a032000-11-30 05:22:44 +0000816- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000817
818- struct: Check ranges for bytes and shorts.
819
820- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000821 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000822
823- Tkinter: Image objects are now guaranteed to have unique ids. Set
824 event.delta to zero if Tk version doesn't support mousewheel.
825 Removed some debugging prints.
826
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000827- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +0000828
Fred Drake67233bc2000-09-26 16:40:27 +0000829- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000830 which works around a bug in Norton AntiVirus 2000 that leads directly
831 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000832
833- xml: New version detection code allows PyXML to override standard
834 XML package if PyXML version is greater than 0.6.1.
835
Fred Drake64bb3802000-09-26 16:21:35 +0000836- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
837 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
838 tree only for nodes which are sufficiently interesting to a specific
839 application. Does not provide the HTML-specific extensions. Still
840 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000841
Fred Drake64bb3802000-09-26 16:21:35 +0000842- xml.sax: SAX 2 support for Python, including all the handler
843 interfaces needed to process XML 1.0 compliant XML. Some
844 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000845
Fred Drake64bb3802000-09-26 16:21:35 +0000846- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
847 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000848
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000849
Jeremy Hylton1b618592000-09-26 05:32:36 +0000850C API
851
852- Add three new convenience functions for module initialization --
853 PyModule_AddObject(), PyModule_AddIntConstant(), and
854 PyModule_AddStringConstant().
855
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000856- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +0000857 removed and add #error to Python.h if NULL isn't defined after
858 #include of stdio.h.
859
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000860- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +0000861 backwards compatibility (at the source level) with old extensions.
862
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000863- A wrapper API was added for signal() and sigaction(). Instead of
864 either function, always use PyOS_getsig() to get a signal handler
865 and PyOS_setsig() to set one. A new convenience typedef
866 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000867
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000868- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +0000869 internal data buffer and size of a string object -- or the default
870 encoded version of a Unicode object.
871
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000872- PyString_Size() and PyString_AsString() accept Unicode objects.
873
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000874- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +0000875 exists). INT_MAX and LONG_MAX will always be defined, even if
876 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000877
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000878- PyFloat_FromString takes a second argument, pend, that was
879 effectively useless. It is now officially useless but preserved for
880 backwards compatibility. If the pend argument is not NULL, *pend is
881 set to NULL.
882
883- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
884 for the attribute name. See note on getattr() above.
885
886- A few bug fixes to argument processing for Unicode.
887 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
888 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
889 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +0000890 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000891
892- Py_BuildValue accepts B format (for bgen-generated code).
893
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000894
Jeremy Hylton1b618592000-09-26 05:32:36 +0000895Internals
896
897- On Unix, fix code for finding Python installation directory so that
898 it works when argv[0] is a relative path.
899
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +0000900- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000901 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +0000902 rather than by generating a copy of the object.
903
Tim Peters482c0212000-09-26 06:33:09 +0000904- Several of the internal Unicode tables are much smaller now, and
905 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000906
Jeremy Hylton97693b02000-09-26 17:42:51 +0000907- In the garbage collector: Fixed bug in collection of tuples. Fixed
908 bug that caused some instances to be removed from the container set
909 while they were still live. Fixed parsing in gc.set_debug() for
910 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000911
912- Fixed refcount problem in instance deallocation that only occurred
913 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
914
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000915- On Windows, getpythonregpath is now protected against null data in
916 registry key.
917
918- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +0000919 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000920
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000921
Jeremy Hylton1b618592000-09-26 05:32:36 +0000922Build and platform-specific issues
923
924- Better support of GNU Pth via --with-pth configure option.
925
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000926- Python/C API now properly exposed to dynamically-loaded extension
927 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +0000928
929- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
930 Don't define MS_SYNC to be zero when it is undefined. Added missing
931 prototypes in posixmodule.c.
932
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000933- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +0000934 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +0000935
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000936- Fix largefile support on older NetBSD systems and OpenBSD by adding
937 define for TELL64.
938
939
940Tools and other miscellany
941
942- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
943
944- freeze: The modulefinder now works with 2.0 opcodes.
945
Tim Petersa3a3a032000-11-30 05:22:44 +0000946- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +0000947 Move hackery of sys.argv until after the Tk instance has been
948 created, which allows the application-specific Tkinter
949 initialization to be executed if present; also pass an explicit
950 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +0000951
Jeremy Hylton1b618592000-09-26 05:32:36 +0000952
953What's new in 2.0 beta 1?
954=========================
955
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000956Source Incompatibilities
957------------------------
958
959None. Note that 1.6 introduced several incompatibilities with 1.5.2,
960such as single-argument append(), connect() and bind(), and changes to
961str(long) and repr(float).
962
963
964Binary Incompatibilities
965------------------------
966
967- Third party extensions built for Python 1.5.x or 1.6 cannot be used
968with Python 2.0; these extensions will have to be rebuilt for Python
9692.0.
970
971- On Windows, attempting to import a third party extension built for
972Python 1.5.x or 1.6 results in an immediate crash; there's not much we
973can do about this. Check your PYTHONPATH environment variable!
974
975- Python bytecode files (*.pyc and *.pyo) are not compatible between
976releases.
977
978
979Overview of Changes Since 1.6
980-----------------------------
981
982There are many new modules (including brand new XML support through
983the xml package, and i18n support through the gettext module); a list
984of all new modules is included below. Lots of bugs have been fixed.
985
Jeremy Hylton24c3d602000-09-05 19:36:26 +0000986The process for making major new changes to the language has changed
987since Python 1.6. Enhancements must now be documented by a Python
988Enhancement Proposal (PEP) before they can be accepted.
989
Guido van Rossumf2ffce02000-09-05 04:38:34 +0000990There are several important syntax enhancements, described in more
991detail below:
992
993 - Augmented assignment, e.g. x += 1
994
995 - List comprehensions, e.g. [x**2 for x in range(10)]
996
997 - Extended import statement, e.g. import Module as Name
998
999 - Extended print statement, e.g. print >> file, "Hello"
1000
1001Other important changes:
1002
1003 - Optional collection of cyclical garbage
1004
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001005Python Enhancement Proposal (PEP)
1006---------------------------------
1007
1008PEP stands for Python Enhancement Proposal. A PEP is a design
1009document providing information to the Python community, or describing
1010a new feature for Python. The PEP should provide a concise technical
1011specification of the feature and a rationale for the feature.
1012
1013We intend PEPs to be the primary mechanisms for proposing new
1014features, for collecting community input on an issue, and for
1015documenting the design decisions that have gone into Python. The PEP
1016author is responsible for building consensus within the community and
1017documenting dissenting opinions.
1018
1019The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001020
1021Augmented Assignment
1022--------------------
1023
1024This must have been the most-requested feature of the past years!
1025Eleven new assignment operators were added:
1026
Guido van Rossume905e952000-09-05 12:42:46 +00001027 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001028
1029For example,
1030
1031 A += B
1032
1033is similar to
1034
1035 A = A + B
1036
1037except that A is evaluated only once (relevant when A is something
1038like dict[index].attr).
1039
1040However, if A is a mutable object, A may be modified in place. Thus,
1041if A is a number or a string, A += B has the same effect as A = A+B
1042(except A is only evaluated once); but if a is a list, A += B has the
1043same effect as A.extend(B)!
1044
1045Classes and built-in object types can override the new operators in
1046order to implement the in-place behavior; the not-in-place behavior is
1047used automatically as a fallback when an object doesn't implement the
1048in-place behavior. For classes, the method name is derived from the
1049method name for the corresponding not-in-place operator by inserting
1050an 'i' in front of the name, e.g. __iadd__ implements in-place
1051__add__.
1052
1053Augmented assignment was implemented by Thomas Wouters.
1054
1055
1056List Comprehensions
1057-------------------
1058
1059This is a flexible new notation for lists whose elements are computed
1060from another list (or lists). The simplest form is:
1061
1062 [<expression> for <variable> in <sequence>]
1063
Guido van Rossum56db0952000-09-06 23:34:25 +00001064For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001065This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001066
1067You can also add a condition:
1068
1069 [<expression> for <variable> in <sequence> if <condition>]
1070
1071For example, [w for w in words if w == w.lower()] would yield the list
1072of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001073than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001074
1075You can also have nested for loops and more than one 'if' clause. For
1076example, here's a function that flattens a sequence of sequences::
1077
1078 def flatten(seq):
1079 return [x for subseq in seq for x in subseq]
1080
1081 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1082
1083This prints
1084
1085 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1086
1087List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001088Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001089
1090
1091Extended Import Statement
1092-------------------------
1093
1094Many people have asked for a way to import a module under a different
1095name. This can be accomplished like this:
1096
1097 import foo
1098 bar = foo
1099 del foo
1100
1101but this common idiom gets old quickly. A simple extension of the
1102import statement now allows this to be written as follows:
1103
1104 import foo as bar
1105
1106There's also a variant for 'from ... import':
1107
1108 from foo import bar as spam
1109
1110This also works with packages; e.g. you can write this:
1111
1112 import test.regrtest as regrtest
1113
1114Note that 'as' is not a new keyword -- it is recognized only in this
1115context (this is only possible because the syntax for the import
1116statement doesn't involve expressions).
1117
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001118Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001119
1120
1121Extended Print Statement
1122------------------------
1123
1124Easily the most controversial new feature, this extension to the print
1125statement adds an option to make the output go to a different file
1126than the default sys.stdout.
1127
1128For example, to write an error message to sys.stderr, you can now
1129write:
1130
1131 print >> sys.stderr, "Error: bad dog!"
1132
1133As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00001134evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001135
1136 print >> None, "Hello world"
1137
1138is equivalent to
1139
1140 print "Hello world"
1141
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001142Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001143
1144
1145Optional Collection of Cyclical Garbage
1146---------------------------------------
1147
1148Python is now equipped with a garbage collector that can hunt down
1149cyclical references between Python objects. It's no replacement for
1150reference counting; in fact, it depends on the reference counts being
1151correct, and decides that a set of objects belong to a cycle if all
1152their reference counts can be accounted for from their references to
1153each other. This devious scheme was first proposed by Eric Tiedemann,
1154and brought to implementation by Neil Schemenauer.
1155
1156There's a module "gc" that lets you control some parameters of the
1157garbage collection. There's also an option to the configure script
1158that lets you enable or disable the garbage collection. In 2.0b1,
1159it's on by default, so that we (hopefully) can collect decent user
1160experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00001161performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001162off by default in the final 2.0 release.
1163
1164
1165Smaller Changes
1166---------------
1167
1168A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
1169map(None, seq1, seq2, ...) when the sequences have the same length;
1170i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
1171the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001172zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001173
1174sys.version_info is a tuple (major, minor, micro, level, serial).
1175
1176Dictionaries have an odd new method, setdefault(key, default).
1177dict.setdefault(key, default) returns dict[key] if it exists; if not,
1178it sets dict[key] to default and returns that value. Thus:
1179
1180 dict.setdefault(key, []).append(item)
1181
1182does the same work as this common idiom:
1183
1184 if not dict.has_key(key):
1185 dict[key] = []
1186 dict[key].append(item)
1187
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001188There are two new variants of SyntaxError that are raised for
1189indentation-related errors: IndentationError and TabError.
1190
1191Changed \x to consume exactly two hex digits; see PEP 223. Added \U
1192escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001193
1194The limits on the size of expressions and file in Python source code
1195have been raised from 2**16 to 2**32. Previous versions of Python
1196were limited because the maximum argument size the Python VM accepted
1197was 2**16. This limited the size of object constructor expressions,
1198e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
1199limit was raised thanks to a patch by Charles Waldman that effectively
1200fixes the problem. It is now much more likely that you will be
1201limited by available memory than by an arbitrary limit in Python.
1202
1203The interpreter's maximum recursion depth can be modified by Python
1204programs using sys.getrecursionlimit and sys.setrecursionlimit. This
1205limit is the maximum number of recursive calls that can be made by
1206Python code. The limit exists to prevent infinite recursion from
1207overflowing the C stack and causing a core dump. The default value is
12081000. The maximum safe value for a particular platform can be found
1209by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001210
1211New Modules and Packages
1212------------------------
1213
1214atexit - for registering functions to be called when Python exits.
1215
1216imputil - Greg Stein's alternative API for writing custom import
1217hooks.
1218
1219pyexpat - an interface to the Expat XML parser, contributed by Paul
1220Prescod.
1221
1222xml - a new package with XML support code organized (so far) in three
1223subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
1224would fill a volume. There's a special feature whereby a
1225user-installed package named _xmlplus overrides the standard
1226xmlpackage; this is intended to give the XML SIG a hook to distribute
1227backwards-compatible updates to the standard xml package.
1228
1229webbrowser - a platform-independent API to launch a web browser.
1230
1231
Guido van Rossume905e952000-09-05 12:42:46 +00001232Changed Modules
1233---------------
1234
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001235array -- new methods for array objects: count, extend, index, pop, and
1236remove
1237
1238binascii -- new functions b2a_hex and a2b_hex that convert between
1239binary data and its hex representation
1240
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001241calendar -- Many new functions that support features including control
1242over which day of the week is the first day, returning strings instead
1243of printing them. Also new symbolic constants for days of week,
1244e.g. MONDAY, ..., SUNDAY.
1245
1246cgi -- FieldStorage objects have a getvalue method that works like a
1247dictionary's get method and returns the value attribute of the object.
1248
1249ConfigParser -- The parser object has new methods has_option,
1250remove_section, remove_option, set, and write. They allow the module
1251to be used for writing config files as well as reading them.
1252
1253ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00001254optionally support the RFC 959 REST command.
1255
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001256gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00001257
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001258httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
1259the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00001260
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001261locale -- implement getdefaultlocale for Win32 and Macintosh
1262
1263marshal -- no longer dumps core when marshaling deeply nested or
1264recursive data structures
1265
1266os -- new functions isatty, seteuid, setegid, setreuid, setregid
1267
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001268os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
1269support under Unix.
1270
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001271os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001272
1273os.path -- fix semantics of os.path.commonprefix
1274
1275smtplib -- support for sending very long messages
1276
1277socket -- new function getfqdn()
1278
1279readline -- new functions to read, write and truncate history files.
1280The readline section of the library reference manual contains an
1281example.
1282
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001283select -- add interface to poll system call
1284
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001285shutil -- new copyfileobj function
1286
1287SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
1288HTTP server.
1289
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001290Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001291
1292urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00001293e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001294
1295whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00001296
1297
1298Obsolete Modules
1299----------------
1300
1301None. However note that 1.6 made a whole slew of modules obsolete:
1302stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
1303poly, zmod, strop, util, whatsound.
1304
1305
1306Changed, New, Obsolete Tools
1307----------------------------
1308
Tim Peters8b092332000-09-05 20:15:25 +00001309None.
Guido van Rossume905e952000-09-05 12:42:46 +00001310
1311
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001312C-level Changes
1313---------------
1314
1315Several cleanup jobs were carried out throughout the source code.
1316
1317All C code was converted to ANSI C; we got rid of all uses of the
1318Py_PROTO() macro, which makes the header files a lot more readable.
1319
1320Most of the portability hacks were moved to a new header file,
1321pyport.h; several other new header files were added and some old
1322header files were removed, in an attempt to create a more rational set
1323of header files. (Few of these ever need to be included explicitly;
1324they are all included by Python.h.)
1325
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001326Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001327and Win64, especially for the new Intel Itanium processor. Mick also
1328added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001329
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001330The C APIs to return an object's size have been update to consistently
1331use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
1332previous versions, the abstract interfaces used PyXXX_Length and the
1333concrete interfaces used PyXXX_Size. The old names,
1334e.g. PyObject_Length, are still available for backwards compatibility
1335at the API level, but are deprecated.
1336
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001337The PyOS_CheckStack function has been implemented on Windows by
1338Fredrik Lundh. It prevents Python from failing with a stack overflow
1339on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001340
1341The GC changes resulted in creation of two new slots on object,
1342tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00001343the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001344
1345The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00001346C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001347
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001348PyErr_Format has been updated to automatically calculate the size of
1349the buffer needed to hold the formatted result string. This change
1350prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00001351
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001352New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00001353
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001354PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
1355that are the same as their non-Ex counterparts except they take an
1356extra flag argument that tells them to close the file when done.
1357
1358XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001359
Tim Peters8b092332000-09-05 20:15:25 +00001360
1361Windows Changes
1362---------------
1363
1364New popen2/popen3/peopen4 in os module (see Changed Modules above).
1365
1366os.popen is much more usable on Windows 95 and 98. See Microsoft
1367Knowledge Base article Q150956. The Win9x workaround described there
1368is implemented by the new w9xpopen.exe helper in the root of your
1369Python installation. Note that Python uses this internally; it is not
1370a standalone program.
1371
1372Administrator privileges are no longer required to install Python
1373on Windows NT or Windows 2000. If you have administrator privileges,
1374Python's registry info will be written under HKEY_LOCAL_MACHINE.
1375Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00001376under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00001377uses of Python, but will prevent some advanced uses from working
1378(for example, running a Python script as an NT service, or possibly
1379from CGI).
1380
1381[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
1382installer; instead, it installs the needed Tcl/Tk files directly in the
1383Python directory. If you already have a Tcl/Tk installation, this
1384wastes some disk space (about 4 Megs) but avoids problems with
1385conflicting Tcl/Tk installations, and makes it much easier for Python
1386to ensure that Tcl/Tk can find all its files.
1387
1388[This was new in 1.6] The Windows installer now installs by default in
1389\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
1390
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001391
1392Updates to the changes between 1.5.2 and 1.6
1393--------------------------------------------
1394
1395The 1.6 NEWS file can't be changed after the release is done, so here
1396is some late-breaking news:
1397
1398New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
1399and changes to getlocale() and setlocale().
1400
1401The new module is now enabled per default.
1402
1403It is not true that the encodings codecs cannot be used for normal
1404strings: the string.encode() (which is also present on 8-bit strings
1405!) allows using them for 8-bit strings too, e.g. to convert files from
1406cp1252 (Windows) to latin-1 or vice-versa.
1407
1408Japanese codecs are available from Tamito KAJIYAMA:
1409http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
1410
1411
Guido van Rossumab9d6f01998-08-10 22:01:13 +00001412======================================================================