blob: a4d739517a16edb86c054473aa4121256750ab3c [file] [log] [blame]
Tim Petersedc99312001-08-22 21:36:50 +00001What's New in Python 2.2a3?
2===========================
3
4Core
5
Tim Peters9fffa3e2001-09-04 05:14:19 +00006- Conversion of long to float now raises OverflowError if the long is too
7 big to represent as a C double.
8
Tim Peters32f453e2001-09-03 08:35:41 +00009- The 3-argument builtin pow() no longer allows a third non-None argument
10 if either of the first two arguments is a float, or if both are of
11 integer types and the second argument is negative (in which latter case
12 the arguments are converted to float, so this is really the same
13 restriction).
14
Tim Peters5d2b77c2001-09-03 05:47:38 +000015- The builtin dir() now returns more information, and sometimes much
16 more, generally naming all attributes of an object, and all attributes
17 reachable from the object via its class, and from its class's base
18 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
19 an empty list. In 2.2a3,
20
21 >>> dir([])
22 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
23 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
24 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
25 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
26 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
27 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
28 'reverse', 'sort']
29
30 dir(module) continues to return only the module's attributes, though.
31
Tim Petersbdee63f2001-09-02 03:40:59 +000032- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +000033 than raising OverflowError. This is a partial implementation of PEP
34 237. You can use -Wdefault::OverflowWarning to enable a warning for
35 this situation, and -Werror::OverflowWarning to revert to the old
36 OverflowError exception.
37
Guido van Rossum61c345f2001-09-04 03:26:15 +000038- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +000039 warnings for the use of classic division. (See PEP 238.) Possible
Guido van Rossum61c345f2001-09-04 03:26:15 +000040 values are -Qold, -Qwarn, and -Qnew. The default is -Qold, meaning
Guido van Rossumae457142001-08-31 18:31:35 +000041 the / operator has its classic meaning and no warnings are issued.
Guido van Rossum61c345f2001-09-04 03:26:15 +000042 Using -Qwarn issues a run-time warning about all uses of classic
43 division for int, long, float and complex arguments. Using -Qnew is
Guido van Rossumae457142001-08-31 18:31:35 +000044 questionable; it turns on new division by default, but only in the
Guido van Rossum61c345f2001-09-04 03:26:15 +000045 __main__ module. You can usefully combine -Qwarn and -Qnew: this
Guido van Rossumae457142001-08-31 18:31:35 +000046 gives the __main__ module new division, and warns about classic
47 division everywhere else.
48
Tim Petersbdee63f2001-09-02 03:40:59 +000049- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +000050 long, float, str, unicode, and tuple. (The types complex, list and
51 dictionary can also be subclassed; this was introduced earlier.)
52 Note that restrictions apply when subclassing immutable built-in
53 types: you can only affect the value of the instance by overloading
54 __new__. You can add mutable attributes, and the subclass instances
55 will have a __dict__ attribute, but you cannot change the "value"
56 (as implemented by the base class) of an immutable subclass instance
57 once it is created.
58
Guido van Rossumaaf80c82001-09-02 13:44:35 +000059- The dictionary constructor now takes an optional argument, a
60 mapping-like object, and initializes the dictionary from its
61 (key, value) pairs.
62
Tim Petersbdee63f2001-09-02 03:40:59 +000063- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +000064 "cooperative super calls" in a multiple inheritance setting. For an
65 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
66
Tim Petersbdee63f2001-09-02 03:40:59 +000067- A new built-in type, getset, has been added. This enables the
Guido van Rossumae457142001-08-31 18:31:35 +000068 creation of "computed attributes". Such attributes are implemented
69 by getter and setter functions (or only one of these for read-only
70 or write-only attributes), without the need to override
71 __getattr__. See http://www.python.org/2.2/descrintro.html#getset
72
Tim Petersbdee63f2001-09-02 03:40:59 +000073- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +000074 liberalized, to allow leading zeroes. Examples of literals now
75 legal that were SyntaxErrors before:
76
77 00.0 0e3 0100j 07.5 00000000000000000008.
78
Tim Petersbdee63f2001-09-02 03:40:59 +000079- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +000080 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
81
Tim Petersedc99312001-08-22 21:36:50 +000082Library
83
Martin v. Löwis44f86962001-09-05 13:44:54 +000084- Asynchronous timeout actions are available through the new class
85 threading.Timer.
86
Tim Peters78526162001-09-05 00:53:45 +000087- math.log and math.log10 now return sensible results for even huge
88 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
89
Tim Petersbdee63f2001-09-02 03:40:59 +000090- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +000091 currently held. See the docs for the imp module.
92
Tim Petersbdee63f2001-09-02 03:40:59 +000093- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +000094 dumps containing ints written on platforms where Python ints are 8 bytes.
95 When read on a box where Python ints are 4 bytes, such values are
96 converted to Python longs.
97
Tim Petersbdee63f2001-09-02 03:40:59 +000098- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +000099 code objects is no longer allowed. This plugs a security hole.
100
Tim Petersedc99312001-08-22 21:36:50 +0000101Tools
102
103Build
104
Tim Peters7eea37e2001-09-04 22:08:56 +0000105C API
106
107- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000108
Tim Peters9fffa3e2001-09-04 05:14:19 +0000109- Note that PyLong_AsDouble can fail! This has always been true, but no
110 callers checked for it. It's more likely to fail now, because overflow
111 errors are properly detected now. The proper way to check:
112
113 double x = PyLong_AsDouble(some_long_object);
114 if (x == -1.0 && PyErr_Occurred()) {
115 /* The conversion failed. */
116 }
117
Tim Petersbdee63f2001-09-02 03:40:59 +0000118- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000119 compile but will not participate in GC. To upgrade an extension
120 module:
121
122 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000123
Neil Schemenauer4042c692001-08-30 15:38:01 +0000124 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
125 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000126
Neil Schemenauer4042c692001-08-30 15:38:01 +0000127 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
128 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000129
Neil Schemenauer4042c692001-08-30 15:38:01 +0000130 - remove PyGC_HEAD_SIZE from object size calculations
131
132 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
133
Tim Petersbdee63f2001-09-02 03:40:59 +0000134- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000135 These can be used safely to construct string objects from a
136 sprintf-style format string (similar to the format string supported
137 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000138
Tim Petersedc99312001-08-22 21:36:50 +0000139New platforms
140
Tim Petersb7da0902001-09-02 23:01:43 +0000141- Stephen Hansen contributed patches sufficient to get a clean compile
142 under Borland C (Windows), but he reports problems running it and ran
143 out of time to complete the port. Volunteers? Expect a MemoryError
144 when importing the types module; this is probably shallow, and
145 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000146
Tim Petersedc99312001-08-22 21:36:50 +0000147Tests
148
149Windows
150
Tim Petersbdee63f2001-09-02 03:40:59 +0000151- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000152 points to command.com (patch from Brian Quinlan).
153
Tim Petersedc99312001-08-22 21:36:50 +0000154
Tim Peters20f51a72001-07-21 02:31:40 +0000155What's New in Python 2.2a2?
156===========================
157
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000158Build
159
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000160- Tim Peters developed a brand new Windows installer using Wise 8.1,
161 generously donated to us by Wise Solutions.
162
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000163- configure supports a new option --enable-unicode, with the values
164 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
165 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000166
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000167- A new configure option --enable-framework builds a Mac OS X framework,
168 which "make frameworkinstall" will install. This provides a starting
169 point for more mac-like functionality, join pythonmac-sig@python.org
170 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000171
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000172- The NeXT platform is no longer supported.
173
174- The `new' module is now statically linked.
175
Tim Peters0afb6092001-08-15 06:06:44 +0000176Tools
177
178- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000179 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000180 the module docstring for details.
181
Tim Peters20f51a72001-07-21 02:31:40 +0000182Tests
183
Tim Peters5e824c32001-08-12 22:25:01 +0000184- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000185 platforms, allowing to give clearer test result output. regrtest
186 also has optional --use/-u switch to run normally disabled tests
187 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000188
Tim Peters20f51a72001-07-21 02:31:40 +0000189- Several new tests in the standard test suite, with special thanks to
190 Nick Mathewson.
191
192Core
193
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000194- The floor division operator // has been added as outlined in PEP
195 238. The / operator still provides classic division (and will until
196 Python 3.0) unless "from __future__ import division" is included, in
197 which case the / operator will provide true division. The operator
198 module provides truediv() and floordiv() functions. Augmented
199 assignment variants are included, as are the equivalent overloadable
200 methods and C API methods. See the PEP for a full discussion:
201 <http://python.sf.net/peps/pep-0238.html>
202
Tim Peters6cd6a822001-08-17 22:11:27 +0000203- Future statements are now effective in simulated interactive shells
204 (like IDLE). This should "just work" by magic, but read Michael
205 Hudson's "Future statements in simulated shells" PEP 264 for full
206 details: <http://python.sf.net/peps/pep-0264.html>.
207
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000208- The type/class unification (PEP 252-253) was integrated into the
209 trunk and is not so tentative any more (the exact specification of
210 some features is still tentative). A lot of work has done on fixing
211 bugs and adding robustness and features (performance still has to
212 come a long way).
213
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000214- Warnings about a mismatch in the Python API during extension import
215 now use the Python warning framework (which makes it possible to
216 write filters for these warnings).
217
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000218- A function's __dict__ (aka func_dict) will now always be a
219 dictionary. It used to be possible to delete it or set it to None,
220 but now both actions raise TypeErrors. It is still legal to set it
221 to a dictionary object. Getting func.__dict__ before any attributes
222 have been assigned now returns an empty dictionary instead of None.
223
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000224Library
225
Tim Peters5e824c32001-08-12 22:25:01 +0000226- New class Differ and new functions ndiff() and restore() in difflib.py.
227 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000228 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000229
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000230- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
231 value using the minimal quoting required for the value; more
232 reliable than using xml.sax.saxutils.escape() for attribute values.
233
234- Readline completion support for cmd.Cmd was added.
235
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000236- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
237
238- Added function threading.BoundedSemaphore()
239
240- Added Ka-Ping Yee's cgitb.py module.
241
242- The `new' module now exposes the CO_xxx flags.
243
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000244New platforms
245
246C API
247
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000248- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
249 which provide a cross-platform implementations for the
250 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
251 the standard sprintf() and vsprintf() C lib APIs, these versions
252 apply bounds checking on the used buffer which enhances protection
253 against buffer overruns.
254
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000255- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000256 and extensions using different Unicode widths is rendered next to
257 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000258 will result in an ImportError. Unicode extensions writers must make
259 sure to check the Unicode width compatibility in their extensions by
260 using at least one of the mangled Unicode APIs in the extension.
261
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000262- Two new flags METH_NOARGS and METH_O are available in method definition
263 tables to simplify implementation of methods with no arguments and a
264 single untyped argument. Calling such methods is more efficient than
265 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
266 deprecated.
267
Tim Petersc1731372001-08-04 08:12:36 +0000268Windows
269
270- "import module" now compiles module.pyw if it exists and nothing else
271 relevant is found.
272
Tim Peters20f51a72001-07-21 02:31:40 +0000273
Guido van Rossum55a78992001-07-17 17:22:32 +0000274What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000275===========================
276
277Core
Tim Petersa814db52001-05-14 07:05:58 +0000278
Tim Peters6d6c1a32001-08-02 04:15:00 +0000279- TENTATIVELY, a large amount of code implementing much of what's
280 described in PEP 252 (Making Types Look More Like Classes) and PEP
281 253 (Subtyping Built-in Types) was added. This will be released
282 with Python 2.2a1. Documentation will be provided separately
283 through http://www.python.org/2.2/. The purpose of releasing this
284 with Python 2.2a1 is to test backwards compatibility. It is
285 possible, though not likely, that a decision is made not to release
286 this code as part of 2.2 final, if any serious backwards
287 incompapatibilities are found during alpha testing that cannot be
288 repaired.
289
Guido van Rossum55a78992001-07-17 17:22:32 +0000290- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000291 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000292 more 'yield' statements. See PEP 255. Since this adds a new
293 keyword to the language, this feature must be enabled by including a
294 future statement: "from __future__ import generators" (see PEP 236).
295 Generators will become a standard feature in a future release
296 (probably 2.3). Without this future statement, 'yield' remains an
297 ordinary identifier, but a warning is issued each time it is used.
298 (These warnings currently don't conform to the warnings framework of
299 PEP 230; we intend to fix this in 2.2a2.)
300
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000301- The UTF-16 codec was modified to be more RFC compliant. It will now
302 only remove BOM characters at the start of the string and then
303 only if running in native mode (UTF-16-LE and -BE won't remove a
304 leading BMO character).
305
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000306- Strings now have a new method .decode() to complement the already
307 existing .encode() method. These two methods provide direct access
308 to the corresponding decoders and encoders of the registered codecs.
309
310 To enhance the usability of the .encode() method, the special
311 casing of Unicode object return values was dropped (Unicode objects
312 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000313
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000314 Both methods will now return whatever the codec in charge of the
315 requested encoding returns as object, e.g. Unicode codecs will
316 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
317 will return u"äöü"). This enables codec writer to create codecs
318 for various simple to use conversions.
319
320 New codecs were added to demonstrate these new features (the .encode()
321 and .decode() columns indicate the type of the returned objects):
322
323 Name | .encode() | .decode() | Description
324 ----------------------------------------------------------------------
325 uu | string | string | UU codec (e.g. for email)
326 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000327 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000328 zlib | string | string | zlib compression
329 hex | string | string | 2-byte hex codec
330 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
331
Mark Hammond2a0af792001-05-14 03:09:36 +0000332- Some operating systems now support the concept of a default Unicode
333 encoding for file system operations. Notably, Windows supports 'mbcs'
334 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000335 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000336 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000337
338 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000339 functions that return filenames (such as os.listdir()) to return Python
340 string objects pre-encoded using the default file system encoding for
341 the platform. As this encoding is likely to be different from Python's
342 default encoding, converting this name to a Unicode object before passing
343 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000344 would attempt to use its default encoding (generally ASCII) rather than
345 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000346
Tim Petersa814db52001-05-14 07:05:58 +0000347 In general, this change simply removes surprises when working with
348 Unicode and the file system, making these operations work as you expect,
349 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000350 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000351
Tim Peters61dff2b2001-05-08 15:43:37 +0000352- Float (and complex) literals in source code were evaluated to full
353 precision only when running from a .py file; the same code loaded from a
354 .pyc (or .pyo) file could suffer numeric differences starting at about the
355 12th significant decimal digit. For example, on a machine with IEEE-754
356 floating arithmetic,
357
358 x = 9007199254740992.0
359 print long(x)
360
361 printed 9007199254740992 if run directly from .py, but 9007199254740000
362 if from a compiled (.pyc or .pyo) file. This was due to marshal using
363 str(float) instead of repr(float) when building code objects. marshal
364 now uses repr(float) instead, which should reproduce floats to full
365 machine precision (assuming the platform C float<->string I/O conversion
366 functions are of good quality).
367
368 This may cause floating-point results to change in some cases, and
369 usually for the better, but may also cause numerically unstable
370 algorithms to break.
371
Tim Peters2f228e72001-05-13 00:19:31 +0000372- The implementation of dicts suffers fewer collisions, which has speed
373 benefits. However, the order in which dict entries appear in dict.keys(),
374 dict.values() and dict.items() may differ from previous releases for a
375 given dict. Nothing is defined about this order, so no program should
376 rely on it. Nevertheless, it's easy to write test cases that rely on the
377 order by accident, typically because of printing the str() or repr() of a
378 dict to an "expected results" file. See Lib/test/test_support.py's new
379 sortdict(dict) function for a simple way to display a dict in sorted
380 order.
381
Tim Peters7a3bfc32001-06-12 01:22:22 +0000382- Many other small changes to dicts were made, resulting in faster
383 operation along the most common code paths.
384
Guido van Rossum10315822001-05-01 20:54:30 +0000385- Dictionary objects now support the "in" operator: "x in dict" means
386 the same as dict.has_key(x).
387
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000388- The update() method of dictionaries now accepts generic mapping
389 objects. Specifically the argument object must support the .keys()
390 and __getitem__() methods. This allows you to say, for example,
391 {}.update(UserDict())
392
Guido van Rossum10315822001-05-01 20:54:30 +0000393- Iterators were added; this is a generalized way of providing values
394 to a for loop. See PEP 234. There's a new built-in function iter()
395 to return an iterator. There's a new protocol to get the next value
396 from an iterator using the next() method (in Python) or the
397 tp_iternext slot (in C). There's a new protocol to get iterators
398 using the __iter__() method (in Python) or the tp_iter slot (in C).
399 Iterating (i.e. a for loop) over a dictionary generates its keys.
400 Iterating over a file generates its lines.
401
Tim Petersf553f892001-05-01 20:45:31 +0000402- The following functions were generalized to work nicely with iterator
403 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000404 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000405 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
406 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000407 join() method of strings
408 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000409 'x in y' and 'x not in y' (PySequence_Contains() in C API)
410 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000411 right-hand side of assignment statements with multiple targets, such as
412 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000413
Tim Petersd85e1022001-05-11 21:51:48 +0000414- Accessing module attributes is significantly faster (for example,
415 random.random or os.path or yourPythonModule.yourAttribute).
416
Tim Peterse63415e2001-05-08 04:38:29 +0000417- Comparing dictionary objects via == and != is faster, and now works even
418 if the keys and values don't support comparisons other than ==.
419
Tim Peters95bf9392001-05-10 08:32:44 +0000420- Comparing dictionaries in ways other than == and != is slower: there were
421 insecurities in the dict comparison implementation that could cause Python
422 to crash if the element comparison routines for the dict keys and/or
423 values mutated the dicts. Making the code bulletproof slowed it down.
424
Tim Peterseb28ef22001-06-02 05:27:19 +0000425- Collisions in dicts are resolved via a new approach, which can help
426 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000427 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000428 faster now. Thanks to Christian Tismer for pointing out the cause and
429 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000430
Tim Peters52e155e2001-06-16 05:42:57 +0000431- repr() is much faster for large containers (dict, list, tuple).
432
433
Tim Petersa814db52001-05-14 07:05:58 +0000434Library
435
Fred Drake960fdf92001-07-20 18:38:26 +0000436- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
437 were added to the string module. These a locale-indenpendent
438 constants, unlike letters, lowercase, and uppercase. These are now
439 use in appropriate locations in the standard library.
440
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000441- The flags used in dlopen calls can now be configured using
442 sys.setdlopenflags and queried using sys.getdlopenflags.
443
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000444- Fredrik Lundh's xmlrpclib is now a standard library module. This
445 provides full client-side XML-RPC support. In addition,
446 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
447 one asyncore-based). Thanks to Eric Raymond for the documentation.
448
Guido van Rossum643d3912001-07-05 14:46:25 +0000449- The xrange() object is simplified: it no longer supports slicing,
450 repetition, comparisons, efficient 'in' checking, the tolist()
451 method, or the start, stop and step attributes. See PEP 260.
452
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000453- A new function fnmatch.filter to filter lists of file names was added.
454
Barry Warsawffd674d2001-05-22 16:00:10 +0000455- calendar.py uses month and day names based on the current locale.
456
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000457- strop is now *really* obsolete (this was announced before with 1.6),
458 and issues DeprecationWarning when used (except for the four items
459 that are still imported into string.py).
460
Tim Petersa814db52001-05-14 07:05:58 +0000461- Cookie.py now sorts key+value pairs by key in output strings.
462
463- pprint.isrecursive(object) didn't correctly identify recursive objects.
464 Now it does.
465
Tim Peters95b3f782001-05-14 18:39:41 +0000466- pprint functions now much faster for large containers (tuple, list, dict).
467
Tim Peters7b9542a2001-06-10 23:40:19 +0000468- New 'q' and 'Q' format codes in the struct module, corresponding to C
469 types "long long" and "unsigned long long" (on Windows, __int64). In
470 native mode, these can be used only when the platform C compiler supports
471 these types (when HAVE_LONG_LONG is #define'd by the Python config
472 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000473 In standard mode, 'q' and 'Q' are supported on all platforms, and are
474 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000475
Guido van Rossum83213cc2001-06-12 16:48:52 +0000476- The site module installs a new built-in function 'help' that invokes
477 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
478 it displays a message reminding the user to use 'help()' or
479 'help(object)'.
480
Tim Petersa814db52001-05-14 07:05:58 +0000481Tests
482
483- New test_mutants.py runs dict comparisons where the key and value
484 comparison operators mutute the dicts randomly during comparison. This
485 rapidly causes Python to crash under earlier releases (not for the faint
486 of heart: it can also cause Win9x to freeze or reboot!).
487
488- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000489 pprint.isreadable() return sensible results. Also verifies that simple
490 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000491
Tim Peters4324aa32001-05-28 22:30:08 +0000492C API
493
494- Removed the unused last_is_sticky argument from the internal
495 _PyTuple_Resize(). If this affects you, you were cheating.
496
497
Guido van Rossum55a78992001-07-17 17:22:32 +0000498======================================================================
499
500
Guido van Rossumffe13be2001-04-16 18:46:45 +0000501What's New in Python 2.1 (final)?
502=================================
503
504We only changed a few things since the last release candidate, all in
505Python library code:
506
507- A bug in the locale module was fixed that affected locales which
508 define no grouping for numeric formatting.
509
510- A few bugs in the weakref module's implementations of weak
511 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
512 and the test suite was updated to check for these bugs.
513
514- An old bug in the os.path.walk() function (introduced in Python
515 2.0!) was fixed: a non-existent file would cause an exception
516 instead of being ignored.
517
518- Fixed a few bugs in the new symtable module found by Neil Norwitz's
519 PyChecker.
520
521
Guido van Rossum5b08f132001-04-16 02:05:23 +0000522What's New in Python 2.1c2?
523===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000524
Guido van Rossum5b08f132001-04-16 02:05:23 +0000525A flurry of small changes, and one showstopper fixed in the nick of
526time made it necessary to release another release candidate. The list
527here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000528
Guido van Rossum5b08f132001-04-16 02:05:23 +0000529Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000530
Guido van Rossum5b08f132001-04-16 02:05:23 +0000531- Tim discovered a nasty bug in the dictionary code, caused by
532 PyDict_Next() calling dict_resize(), and the GC code's use of
533 PyDict_Next() violating an assumption in dict_items(). This was
534 fixed with considerable amounts of band-aid, but the net effect is a
535 saner and more robust implementation.
536
537- Made a bunch of symbols static that were accidentally global.
538
539Build and Ports
540
541- The setup.py script didn't check for a new enough version of zlib
542 (1.1.3 is needed). Now it does.
543
544- Changed "make clean" target to also remove shared libraries.
545
546- Added a more general warning about the SGI Irix optimizer to README.
547
548Library
549
550- Fix a bug in urllib.basejoin("http://host", "../file.html") which
551 omitted the slash between host and file.html.
552
553- The mailbox module's _Mailbox class contained a completely broken
554 and undocumented seek() method. Ripped it out.
555
556- Fixed a bunch of typos in various library modules (urllib2, smtpd,
557 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
558
559- Fixed a few last-minute bugs in unittest.
560
561Extensions
562
563- Reverted the patch to the OpenSSL code in socketmodule.c to support
564 RAND_status() and the EGD, and the subsequent patch that tried to
565 fix it for pre-0.9.5 versions; the problem with the patch is that on
566 some systems it issues a warning whenever socket is imported, and
567 that's unacceptable.
568
569Tests
570
571- Fixed the pickle tests to work with "import test.test_pickle".
572
573- Tweaked test_locale.py to actually run the test Windows.
574
575- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
576 not "wb" (which is not a valid mode at all).
577
578- Fix pstats browser crashes. Import readline if it exists to make
579 the user interface nicer.
580
581- Add "import thread" to the top of test modules that import the
582 threading module (test_asynchat and test_threadedtempfile). This
583 prevents test failures caused by a broken threading module resulting
584 from a previously caught failed import.
585
586- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
587 needed on some platforms (e.g. Solaris 8) when the tests are run
588 twice in succession.
589
590- Skip rather than fail test_sunaudiodev if no audio device is found.
591
592
593What's New in Python 2.1c1?
594===========================
595
596This list was significantly updated when 2.1c2 was released; the 2.1c1
597release didn't mention most changes that were actually part of 2.1c1:
598
599Legal
600
601- Copyright was assigned to the Python Software Foundation (PSF) and a
602 PSF license (very similar to the CNRI license) was added.
603
604- The CNRI copyright notice was updated to include 2001.
605
606Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000607
Guido van Rossumc9932722001-04-12 02:31:27 +0000608- After a public outcry, assignment to __debug__ is no longer illegal;
609 instead, a warning is issued. It will become illegal in 2.2.
610
Guido van Rossum5b08f132001-04-16 02:05:23 +0000611- Fixed a core dump with "%#x" % 0, and changed the semantics so that
612 "%#x" now always prepends "0x", even if the value is zero.
613
614- Fixed some nits in the bytecode compiler.
615
616- Fixed core dumps when calling certain kinds of non-functions.
617
618- Fixed various core dumps caused by reference count bugs.
619
620Build and Ports
621
622- Use INSTALL_SCRIPT to install script files.
623
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000624- New port: SCO Unixware 7, by Billy G. Allie.
625
Guido van Rossum5b08f132001-04-16 02:05:23 +0000626- Updated RISCOS port.
627
628- Updated BeOS port and notes.
629
630- Various other porting problems resolved.
631
632Library
633
634- The TERMIOS and SOCKET modules are now truly obsolete and
635 unnecessary. Their symbols are incorporated in the termios and
636 socket modules.
637
638- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
639 better tests for pickling.
640
641- threading: make Condition.wait() robust against KeyboardInterrupt.
642
643- zipfile: add support to zipfile to support opening an archive
644 represented by an open file rather than a file name. Fix bug where
645 the archive was not properly closed. Fixed a bug in this bugfix
646 where flush() was called for a read-only file.
647
648- imputil: added an uninstall() method to the ImportManager.
649
650- Canvas: fixed bugs in lower() and tkraise() methods.
651
652- SocketServer: API change (added overridable close_request() method)
653 so that the TCP server can explicitly close the request.
654
655- pstats: Eric Raymond added a simple interactive statistics browser,
656 invoked when the module is run as a script.
657
658- locale: fixed a problem in format().
659
660- webbrowser: made it work when the BROWSER environment variable has a
661 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
662 KDE 2. Fixed some other nits.
663
664- unittest: changes to allow using a different exception than
665 AssertionError, and added a few more function aliases. Some other
666 small changes.
667
668- urllib, urllib2: fixed redirect problems and a coupleof other nits.
669
670- asynchat: fixed a critical bug in asynchat that slipped through the
671 2.1b2 release. Fixed another rare bug.
672
673- Fix some unqualified except: clauses (always a bad code example).
674
675XML
676
677- pyexpat: new API get_version_string().
678
679- Fixed some minidom bugs.
680
681Extensions
682
683- Fixed a core dump in _weakref. Removed the weakref.mapping()
684 function (it adds nothing to the API).
685
686- Rationalized the use of header files in the readline module, to make
687 it compile (albeit with some warnings) with the very recent readline
688 4.2, without breaking for earlier versions.
689
690- Hopefully fixed a buffering problem in linuxaudiodev.
691
692- Attempted a fix to make the OpenSSL support in the socket module
693 work again with pre-0.9.5 versions of OpenSSL.
694
695Tests
696
697- Added a test case for asynchat and asyncore.
698
699- Removed coupling between tests where one test failing could break
700 another.
701
702Tools
703
704- Ping added an interactive help browser to pydoc, fixed some nits
705 in the rest of the pydoc code, and added some features to his
706 inspect module.
707
708- An updated python-mode.el version 4.1 which integrates Ken
709 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
710 much nicer in XEmacs and Emacs. When stepping through your program
711 with pdb, in either the shell window or the *Python* window, the
712 source file and line will be tracked by an arrow. Very cool!
713
714- IDLE: syntax warnings in interactive mode are changed into errors.
715
716- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000717 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000718
719- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000720
Barry Warsaw11e89c72001-04-11 20:37:57 +0000721
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000722What's New in Python 2.1 beta 2?
723================================
724
Guido van Rossum053ae352001-03-22 14:17:21 +0000725(Unlisted are many fixed bugs, more documentation, etc.)
726
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000727Core language, builtins, and interpreter
728
Guido van Rossum053ae352001-03-22 14:17:21 +0000729- The nested scopes work (enabled by "from __future__ import
730 nested_scopes") is completed; in particular, the future now extends
731 into code executed through exec, eval() and execfile(), and into the
732 interactive interpreter.
733
734- When calling a base class method (e.g. BaseClass.__init__(self)),
735 this is now allowed even if self is not strictly spoken a class
736 instance (e.g. when using metaclasses or the Don Beaudry hook).
737
738- Slice objects are now comparable but not hashable; this prevents
739 dict[:] from being accepted but meaningless.
740
741- Complex division is now calculated using less braindead algorithms.
742 This doesn't change semantics except it's more likely to give useful
743 results in extreme cases. Complex repr() now uses full precision
744 like float repr().
745
746- sgmllib.py now calls handle_decl() for simple <!...> declarations.
747
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000748- It is illegal to assign to the name __debug__, which is set when the
749 interpreter starts. It is effectively a compile-time constant.
750
751- A warning will be issued if a global statement for a variable
752 follows a use or assignment of that variable.
753
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000754Standard library
755
Guido van Rossum053ae352001-03-22 14:17:21 +0000756- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
757 inspired by JUnit), is now part of the standard library. You now
758 have a choice of two testing frameworks: unittest requires you to
759 write testcases as separate code, doctest gathers them from
760 docstrings. Both approaches have their advantages and
761 disadvantages.
762
763- A new module Tix was added, which wraps the Tix extension library
764 for Tk. With that module, it is not necessary to statically link
765 Tix with _tkinter, since Tix will be loaded with Tcl's "package
766 require" command. See Demo/tix/.
767
768- tzparse.py is now obsolete.
769
770- In gzip.py, the seek() and tell() methods are removed -- they were
771 non-functional anyway, and it's better if callers can test for their
772 existence with hasattr().
773
774Python/C API
775
776- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
777 that's already in the dictionary during a PyDict_Next() iteration.
778 This used to fail occasionally when a dictionary resize operation
779 could be triggered that would rehash all the keys. All other
780 modifications to the dictionary are still off-limits during a
781 PyDict_Next() iteration!
782
783- New extended APIs related to passing compiler variables around.
784
785- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
786 implement isinstance() and issubclass().
787
788- Py_BuildValue() now has a "D" conversion to create a Python complex
789 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000790
Fred Drake4e262a92001-03-22 18:26:47 +0000791- Extensions types which support weak references must now set the
792 field allocated for the weak reference machinery to NULL themselves;
793 this is done to avoid the cost of checking each object for having a
794 weakly referencable type in PyObject_INIT(), since most types are
795 not weakly referencable.
796
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000797- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
798 free variables and cell variables to and from the frame's f_locals.
799
800- Variants of several functions defined in pythonrun.h have been added
801 to support the nested_scopes future statement. The variants all end
802 in Flags and take an extra argument, a PyCompilerFlags *; examples:
803 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
804 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000805 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000806
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000807Distutils
808
809- the sdist command now writes a PKG-INFO file, as described in PEP 241,
810 into the release tree.
811
Tim Peters0e57abf2001-05-02 07:39:38 +0000812- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000813 (an uninstaller, more customization of the installer's display)
814
815- from Jack Jansen: added Mac-specific code to generate a dialog for
816 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000817 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000818 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000819
820- added 'platforms' and 'keywords' to the set of metadata that can be
821 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000822
823- applied patches from Jason Tishler to make the compiler class work with
824 Cygwin.
825
826
Tim Peters2fe289a2001-03-01 22:19:38 +0000827What's New in Python 2.1 beta 1?
828================================
Tim Petersd66595f2001-02-04 03:09:53 +0000829
830Core language, builtins, and interpreter
831
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000832- Following an outcry from the community about the amount of code
833 broken by the nested scopes feature introduced in 2.1a2, we decided
834 to make this feature optional, and to wait until Python 2.2 (or at
835 least 6 months) to make it standard. The option can be enabled on a
836 per-module basis by adding "from __future__ import nested_scopes" at
837 the beginning of a module (before any other statements, but after
838 comments and an optional docstring). See PEP 236 (Back to the
839 __future__) for a description of the __future__ statement. PEP 227
840 (Statically Nested Scopes) has been updated to reflect this change,
841 and to clarify the semantics in a number of endcases.
842
843- The nested scopes code, when enabled, has been hardened, and most
844 bugs and memory leaks in it have been fixed.
845
846- Compile-time warnings are now generated for a number of conditions
847 that will break or change in meaning when nested scopes are enabled:
848
849 - Using "from...import *" or "exec" without in-clause in a function
850 scope that also defines a lambda or nested function with one or
851 more free (non-local) variables. The presence of the import* or
852 bare exec makes it impossible for the compiler to determine the
853 exact set of local variables in the outer scope, which makes it
854 impossible to determine the bindings for free variables in the
855 inner scope. To avoid the warning about import *, change it into
856 an import of explicitly name object, or move the import* statement
857 to the global scope; to avoid the warning about bare exec, use
858 exec...in... (a good idea anyway -- there's a possibility that
859 bare exec will be deprecated in the future).
860
861 - Use of a global variable in a nested scope with the same name as a
862 local variable in a surrounding scope. This will change in
863 meaning with nested scopes: the name in the inner scope will
864 reference the variable in the outer scope rather than the global
865 of the same name. To avoid the warning, either rename the outer
866 variable, or use a global statement in the inner function.
867
Neil Schemenauera35c6882001-02-27 04:45:05 +0000868- An optional object allocator has been included. This allocator is
869 optimized for Python objects and should be faster and use less memory
870 than the standard system allocator. It is not enabled by default
871 because of possible thread safety problems. The allocator is only
872 protected by the Python interpreter lock and it is possible that some
873 extension modules require a thread safe allocator. The object
874 allocator can be enabled by providing the "--with-pymalloc" option to
875 configure.
876
Tim Petersd66595f2001-02-04 03:09:53 +0000877Standard library
878
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000879- pyexpat now detects the expat version if expat.h defines it. A
880 number of additional handlers are provided, which are only available
881 since expat 1.95. In addition, the methods SetParamEntityParsing and
882 GetInputContext of Parser objects are available with 1.95.x
883 only. Parser objects now provide the ordered_attributes and
884 specified_attributes attributes. A new module expat.model was added,
885 which offers a number of additional constants if 1.95.x is used.
886
887- xml.dom offers the new functions registerDOMImplementation and
888 getDOMImplementation.
889
890- xml.dom.minidom offers a toprettyxml method. A number of DOM
891 conformance issues have been resolved. In particular, Element now
892 has an hasAttributes method, and the handling of namespaces was
893 improved.
894
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000895- Ka-Ping Yee contributed two new modules: inspect.py, a module for
896 getting information about live Python code, and pydoc.py, a module
897 for interactively converting docstrings to HTML or text.
898 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000899 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000900 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
901 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000902
Tim Peters1eff7962001-03-01 02:31:33 +0000903- New library module difflib.py, primarily packaging the SequenceMatcher
904 class at the heart of the popular ndiff.py file-comparison tool.
905
906- doctest.py (a framework for verifying Python code examples in docstrings)
907 is now part of the std library.
908
Tim Petersd66595f2001-02-04 03:09:53 +0000909Windows changes
910
Guido van Rossume3955a82001-03-02 14:05:59 +0000911- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
912 small GUI that lets you browse the module docstrings using your
913 default web browser.
914
Tim Peters1eff7962001-03-01 02:31:33 +0000915- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
916 Platforms) is implemented. See
917
918 http://python.sourceforge.net/peps/pep-0235.html
919
920 for full details, especially the "Current Lower-Left Semantics" section.
921 The new Windows import rules are simpler than before:
922
923 A. If the PYTHONCASEOK environment variable exists, same as
924 before: silently accept the first case-insensitive match of any
925 kind; raise ImportError if none found.
926
927 B. Else search sys.path for the first case-sensitive match; raise
928 ImportError if none found.
929
930 The same rules have been implented on other platforms with case-
931 insensitive but case-preserving filesystems too (including Cygwin, and
932 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000933
Tim Peters25a9ce32001-02-19 07:06:36 +0000934- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
935 what it's supposed to do (and does do under NT and 2000) via direct
936 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000937 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000938 all Win9x systems before.
939
Tim Peters1eff7962001-03-01 02:31:33 +0000940- Build: Subproject _test (effectively) renamed to _testcapi.
941
Tim Peters2fe289a2001-03-01 22:19:38 +0000942New platforms
943
944- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
945 Thanks to Steven Majewski!
946
947- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
948 Tishler!
949
Guido van Rossum9089b272001-03-02 06:49:50 +0000950- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
951 Schwertberger! See RISCOS/README for more information -- it seems
952 that because of the bizarre filename conventions on RISCOS, no port
953 to that platform is easy. Note that the new variable os.endsep is
954 silently supported in order to make life easier on this platform,
955 but we don't advertise it because it's not worth for most folks to
956 care about RISCOS portability.
957
Tim Peters25a9ce32001-02-19 07:06:36 +0000958
Tim Petersd7b5e882001-01-25 03:36:26 +0000959What's New in Python 2.1 alpha 2?
960=================================
Tim Peters40ead762001-01-27 05:35:26 +0000961
Tim Petersd7b5e882001-01-25 03:36:26 +0000962Core language, builtins, and interpreter
963
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000964- Scopes nest. If a name is used in a function or class, but is not
965 local, the definition in the nearest enclosing function scope will
966 be used. One consequence of this change is that lambda statements
967 could reference variables in the namespaces where the lambda is
968 defined. In some unusual cases, this change will break code.
969
970 In all previous version of Python, names were resolved in exactly
971 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000972 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000973 function A is defined within a function B, the names bound in B are
974 not visible in A. The new rules make names bound in B visible in A,
975 unless A contains a name binding that hides the binding in B.
976
977 Section 4.1 of the reference manual describes the new scoping rules
978 in detail. The test script in Lib/test/test_scope.py demonstrates
979 some of the effects of the change.
980
981 The new rules will cause existing code to break if it defines nested
982 functions where an outer function has local variables with the same
983 name as globals or builtins used by the inner function. Example:
984
985 def munge(str):
986 def helper(x):
987 return str(x)
988 if type(str) != type(''):
989 str = helper(str)
990 return str.strip()
991
992 Under the old rules, the name str in helper() is bound to the
993 builtin function str(). Under the new rules, it will be bound to
994 the argument named str and an error will occur when helper() is
995 called.
996
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000997- The compiler will report a SyntaxError if "from ... import *" occurs
998 in a function or class scope. The language reference has documented
999 that this case is illegal, but the compiler never checked for it.
1000 The recent introduction of nested scope makes the meaning of this
1001 form of name binding ambiguous. In a future release, the compiler
1002 may allow this form when there is no possibility of ambiguity.
1003
Tim Peters40ead762001-01-27 05:35:26 +00001004- repr(string) is easier to read, now using hex escapes instead of octal,
1005 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1006
1007 >>> "\texample \r\n" + chr(0) + chr(255)
1008 '\texample \r\n\x00\xff' # in 2.1
1009 '\011example \015\012\000\377' # in 2.0
1010
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001011- Functions are now compared and hashed by identity, not by value, since
1012 the func_code attribute is writable.
1013
Fred Drakefb9d7122001-02-01 20:00:40 +00001014- Weak references (PEP 205) have been added. This involves a few
1015 changes in the core, an extension module (_weakref), and a Python
1016 module (weakref). The weakref module is the public interface. It
1017 includes support for "explicit" weak references, proxy objects, and
1018 mappings with weakly held values.
1019
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001020- A 'continue' statement can now appear in a try block within the body
1021 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001022 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001023
Tim Petersd7b5e882001-01-25 03:36:26 +00001024Standard library
1025
Barry Warsaw30dbd142001-01-31 22:14:01 +00001026- mailbox.py now has a new class, PortableUnixMailbox which is
1027 identical to UnixMailbox but uses a more portable scheme for
1028 determining From_ separators. Also, the constructors for all the
1029 classes in this module have a new optional `factory' argument, which
1030 is a callable used when new message classes must be instantiated by
1031 the next() method.
1032
Tim Petersd7b5e882001-01-25 03:36:26 +00001033- random.py is now self-contained, and offers all the functionality of
1034 the now-deprecated whrandom.py. See the docs for details. random.py
1035 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001036 and restoring the internal state of the generator; and jumpahead(n),
1037 for quickly forcing the internal state to be the same as if n calls to
1038 random() had been made. The latter is particularly useful for multi-
1039 threaded programs, creating one instance of the random.Random() class for
1040 each thread, then using .jumpahead() to force each instance to use a
1041 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001042
Tim Peters0de88fc2001-02-01 04:59:18 +00001043- random.py's seed() function is new. For bit-for-bit compatibility with
1044 prior releases, use the whseed function instead. The new seed function
1045 addresses two problems: (1) The old function couldn't produce more than
1046 about 2**24 distinct internal states; the new one about 2**45 (the best
1047 that can be done in the Wichmann-Hill generator). (2) The old function
1048 sometimes produced identical internal states when passed distinct
1049 integers, and there was no simple way to predict when that would happen;
1050 the new one guarantees to produce distinct internal states for all
1051 arguments in [0, 27814431486576L).
1052
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001053- The socket module now supports raw packets on Linux. The socket
1054 family is AF_PACKET.
1055
Tim Peters9ea17ac2001-02-02 05:57:15 +00001056- test_capi.py is a start at running tests of the Python C API. The tests
1057 are implemented by the new Modules/_testmodule.c.
1058
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001059- A new extension module, _symtable, provides provisional access to the
1060 internal symbol table used by the Python compiler. A higher-level
1061 interface will be added on top of _symtable in a future release.
1062
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001063- Removed the obsolete soundex module.
1064
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001065- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1066 the isSameNode method; NamedNodeMap the get method.
1067
1068- xml.sax.expatreader supports the lexical handler property; it
1069 generates comment, startCDATA, and endCDATA events.
1070
Tim Petersee826f82001-01-31 19:39:44 +00001071Windows changes
1072
1073- Build procedure: the zlib project is built in a different way that
1074 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001075 the zlib binary used. See PCbuild\readme.txt for details. Your old
1076 zlib-related directories can be deleted; you'll need to download fresh
1077 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001078
Tim Peters9ea17ac2001-02-02 05:57:15 +00001079- Build: New subproject _test for the benefit of test_capi.py (see above).
1080
Tim Petersb16c56f2001-02-02 21:24:51 +00001081- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1082 interface to some Python compiler internals).
1083
1084- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001085 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001086
Tim Petersa3a3a032000-11-30 05:22:44 +00001087What's New in Python 2.1 alpha 1?
1088=================================
1089
1090Core language, builtins, and interpreter
1091
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001092- There is a new Unicode companion to the PyObject_Str() API
1093 called PyObject_Unicode(). It behaves in the same way as the
1094 former, but assures that the returned value is an Unicode object
1095 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001096
Guido van Rossumf98eda02001-01-17 15:54:45 +00001097- The comparison operators support "rich comparison overloading" (PEP
1098 207). C extension types can provide a rich comparison function in
1099 the new tp_richcompare slot in the type object. The cmp() function
1100 and the C function PyObject_Compare() first try the new rich
1101 comparison operators before trying the old 3-way comparison. There
1102 is also a new C API PyObject_RichCompare() (which also falls back on
1103 the old 3-way comparison, but does not constrain the outcome of the
1104 rich comparison to a Boolean result).
1105
1106 The rich comparison function takes two objects (at least one of
1107 which is guaranteed to have the type that provided the function) and
1108 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1109 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1110 object, which may be NotImplemented (in which case the tp_compare
1111 slot function is used as a fallback, if defined).
1112
1113 Classes can overload individual comparison operators by defining one
1114 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001115 __ge__. There are no explicit "reflected argument" versions of
1116 these; instead, __lt__ and __gt__ are each other's reflection,
1117 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1118 reflection (similar at the C level). No other implications are
1119 made; in particular, Python does not assume that == is the Boolean
1120 inverse of !=, or that < is the Boolean inverse of >=. This makes
1121 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001122
1123 Classes or types that want to implement (in)equality tests but not
1124 the ordering operators (i.e. unordered types) should implement ==
1125 and !=, and raise an error for the ordering operators.
1126
Guido van Rossuma88479f2001-01-18 14:28:08 +00001127 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001128 Boolean; e.g. a matrix type might want to return a matrix of bits
1129 for A < B, giving elementwise comparisons. Such types should ensure
1130 that any interpretation of their value in a Boolean context raises
1131 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1132 at the C level) to always raise an exception.
1133
Guido van Rossuma88479f2001-01-18 14:28:08 +00001134- Complex numbers use rich comparisons to define == and != but raise
1135 an exception for <, <=, > and >=. Unfortunately, this also means
1136 that cmp() of two complex numbers raises an exception when the two
1137 numbers differ. Since it is not mathematically meaningful to compare
1138 complex numbers except for equality, I hope that this doesn't break
1139 too much code.
1140
Tim Peters3389f192001-02-18 08:48:49 +00001141- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001142 not defined by the language, other than that it's arbitrary but
1143 consistent (see the Reference Manual). An implementation detail changed
1144 in 2.1a1 such that None now compares less than any other object. Code
1145 relying on this new behavior (like code that relied on the previous
1146 behavior) does so at its own risk.
1147
Barry Warsaw573b5412001-01-15 20:43:18 +00001148- Functions and methods now support getting and setting arbitrarily
1149 named attributes (PEP 232). Functions have a new __dict__
1150 (a.k.a. func_dict) which hold the function attributes. Methods get
1151 and set attributes on their underlying im_func. It is a TypeError
1152 to set an attribute on a bound method.
1153
Guido van Rossum051e3352001-01-15 19:11:10 +00001154- The xrange() object implementation has been improved so that
1155 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1156 limitation that in this case len(xrange(sys.maxint)) can't be
1157 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1158 work fine as long as the index i doesn't actually reach 2**31.
1159 (Python uses regular ints for sequence and string indices; fixing
1160 that is much more work.)
1161
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001162- Two changes to from...import:
1163
Guido van Rossumba381232001-02-03 15:06:40 +00001164 1) "from M import X" now works even if (after loading module M)
1165 sys.modules['M'] is not a real module; it's basically a getattr()
1166 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001167
1168 2) "from M import *" now looks for M.__all__ to decide which names to
1169 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1170 filters out names starting with '_' as before. Whether or not
1171 __all__ exists, there's no restriction on the type of M.
1172
Guido van Rossumf61f1662001-01-10 20:13:55 +00001173- File objects have a new method, xreadlines(). This is the fastest
1174 way to iterate over all lines in a file:
1175
1176 for line in file.xreadlines():
1177 ...do something to line...
1178
1179 See the xreadlines module (mentioned below) for how to do this for
1180 other file-like objects.
1181
1182- Even if you don't use file.xreadlines(), you may expect a speedup on
1183 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001184 quite a bit in platform-specific ways: on systems (like Linux) that
1185 support flockfile(), getc_unlocked(), and funlockfile(), those are
1186 used by default. On systems (like Windows) without getc_unlocked(),
1187 a complicated (but still thread-safe) method using fgets() is used by
1188 default.
1189
Tim Petersd52269b2001-01-25 06:23:18 +00001190 You can force use of the fgets() method by #define'ing
1191 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001192 getc_unlocked()).
1193
Tim Petersd52269b2001-01-25 06:23:18 +00001194 You can force fgets() not to be used by #define'ing
1195 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001196 test_bufio.py fails -- and let us know if it does!).
1197
1198- In addition, the fileinput module, while still slower than the other
1199 methods on most platforms, has been sped up too, by using
1200 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001201
1202- Support for run-time warnings has been added, including a new
1203 command line option (-W) to specify the disposition of warnings.
1204 See the description of the warnings module below.
1205
1206- Extensive changes have been made to the coercion code. This mostly
1207 affects extension modules (which can now implement mixed-type
1208 numerical operators without having to use coercion), but
1209 occasionally, in boundary cases the coercion semantics have changed
1210 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001211 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001212 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001213 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001214
Guido van Rossumf98eda02001-01-17 15:54:45 +00001215- In connection with the coercion changes, a new built-in singleton
1216 object, NotImplemented is defined. This can be returned for
1217 operations that wish to indicate they are not implemented for a
1218 particular combination of arguments. From C, this is
1219 Py_NotImplemented.
1220
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001221- The interpreter accepts now bytecode files on the command line even
1222 if they do not have a .pyc or .pyo extension. On Linux, after executing
1223
Martin v. Löwise214baa2001-02-04 22:37:56 +00001224import imp,sys,string
1225magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1226reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1227open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001228
1229 any byte code file can be used as an executable (i.e. as an argument
1230 to execve(2)).
1231
Tim Peters9940b802000-12-01 07:59:35 +00001232- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001233 character. In 1.6 and earlier, they never produced a sign,
1234 and raised an error if the value of the long was too large
1235 to fit in a Python int. In 2.0, they produced a sign if and
1236 only if too large to fit in an int. This was inconsistent
1237 across platforms (because the size of an int varies across
1238 platforms), and inconsistent with hex() and oct(). Example:
1239
1240 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001241 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001242 'ffffffbe' # in 2.0 and before, on 32-bit machines
1243 >>> hex(-0x42L)
1244 '-0x42L' # in all versions of Python
1245
Tim Peters9940b802000-12-01 07:59:35 +00001246 The behavior of %d formats for negative Python longs remains
1247 the same as in 2.0 (although in 1.6 and before, they raised
1248 an error if the long didn't fit in a Python int).
1249
1250 %u formats don't make sense for Python longs, but are allowed
1251 and treated the same as %d in 2.1. In 2.0, a negative long
1252 formatted via %u produced a sign if and only if too large to
1253 fit in an int. In 1.6 and earlier, a negative long formatted
1254 via %u raised an error if it was too big to fit in an int.
1255
Guido van Rossum3661d392000-12-12 22:10:31 +00001256- Dictionary objects have an odd new method, popitem(). This removes
1257 an arbitrary item from the dictionary and returns it (in the form of
1258 a (key, value) pair). This can be useful for algorithms that use a
1259 dictionary as a bag of "to do" items and repeatedly need to pick one
1260 item. Such algorithms normally end up running in quadratic time;
1261 using popitem() they can usually be made to run in linear time.
1262
Tim Peters36cdad12000-12-29 02:06:45 +00001263Standard library
1264
Thomas Woutersfe385252001-01-19 23:16:56 +00001265- In the time module, the time argument to the functions strftime,
1266 localtime, gmtime, asctime and ctime is now optional, defaulting to
1267 the current time (in the local timezone).
1268
Guido van Rossumda91f222001-01-15 16:36:08 +00001269- The ftplib module now defaults to passive mode, which is deemed a
1270 more useful default given that clients are often inside firewalls
1271 these days. Note that this could break if ftplib is used to connect
1272 to a *server* that is inside a firewall, from outside; this is
1273 expected to be a very rare situation. To fix that, you can call
1274 ftp.set_pasv(0).
1275
Martin v. Löwis10a27872001-01-13 09:54:41 +00001276- The module site now treats .pth files not only for path configuration,
1277 but also supports extensions to the initialization code: Lines starting
1278 with import are executed.
1279
Guido van Rossumf61f1662001-01-10 20:13:55 +00001280- There's a new module, warnings, which implements a mechanism for
1281 issuing and filtering warnings. There are some new built-in
1282 exceptions that serve as warning categories, and a new command line
1283 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1284 turns warnings into errors). warnings.warn(message[, category])
1285 issues a warning message; this can also be called from C as
1286 PyErr_Warn(category, message).
1287
1288- A new module xreadlines was added. This exports a single factory
1289 function, xreadlines(). The intention is that this code is the
1290 absolutely fastest way to iterate over all lines in an open
1291 file(-like) object:
1292
1293 import xreadlines
1294 for line in xreadlines.xreadlines(file):
1295 ...do something to line...
1296
1297 This is equivalent to the previous the speed record holder using
1298 file.readlines(sizehint). Note that if file is a real file object
1299 (as opposed to a file-like object), this is equivalent:
1300
1301 for line in file.xreadlines():
1302 ...do something to line...
1303
Tim Peters36cdad12000-12-29 02:06:45 +00001304- The bisect module has new functions bisect_left, insort_left,
1305 bisect_right and insort_right. The old names bisect and insort
1306 are now aliases for bisect_right and insort_right. XXX_right
1307 and XXX_left methods differ in what happens when the new element
1308 compares equal to one or more elements already in the list: the
1309 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001310 right. Code that doesn't care where equal elements end up should
1311 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001312
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001313- The new curses.panel module wraps the panel library that forms part
1314 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1315
Guido van Rossumf61f1662001-01-10 20:13:55 +00001316- The SocketServer module now sets the allow_reuse_address flag by
1317 default in the TCPServer class.
1318
1319- A new function, sys._getframe(), returns the stack frame pointer of
1320 the caller. This is intended only as a building block for
1321 higher-level mechanisms such as string interpolation.
1322
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001323- The pyexpat module supports a number of new handlers, which are
1324 available only in expat 1.2. If invocation of a callback fails, it
1325 will report an additional frame in the traceback. Parser objects
1326 participate now in garbage collection. If expat reports an unknown
1327 encoding, pyexpat will try to use a Python codec; that works only
1328 for single-byte charsets. The parser type objects is exposed as
1329 XMLParserObject.
1330
1331- xml.dom now offers standard definitions for symbolic node type and
1332 exception code constants, and a hierarchy of DOM exceptions. minidom
1333 was adjusted to use them.
1334
1335- The conformance of xml.dom.minidom to the DOM specification was
1336 improved. It detects a number of additional error cases; the
1337 previous/next relationship works even when the tree is modified;
1338 Node supports the normalize() method; NamedNodeMap, DocumentType and
1339 DOMImplementation classes were added; Element supports the
1340 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1341 method.
1342
Guido van Rossumf61f1662001-01-10 20:13:55 +00001343Build issues
1344
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001345- For Unix (and Unix-compatible) builds, configuration and building of
1346 extension modules is now greatly automated. Rather than having to
1347 edit the Modules/Setup file to indicate which modules should be
1348 built and where their include files and libraries are, a
1349 distutils-based setup.py script now takes care of building most
1350 extension modules. All extension modules built this way are built
1351 as shared libraries. Only a few modules that must be linked
1352 statically are still listed in the Setup file; you won't need to
1353 edit their configuration.
1354
1355- Python should now build out of the box on Cygwin. If it doesn't,
1356 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001357
1358- Python now always uses its own (renamed) implementation of getopt()
1359 -- there's too much variation among C library getopt()
1360 implementations.
1361
1362- C++ compilers are better supported; the CXX macro is always set to a
1363 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001364
Tim Petersd92dfe02000-12-12 01:18:41 +00001365Windows changes
1366
1367- select module: By default under Windows, a select() call
1368 can specify no more than 64 sockets. Python now boosts
1369 this Microsoft default to 512. If you need even more than
1370 that, see the MS docs (you'll need to #define FD_SETSIZE
1371 and recompile Python from source).
1372
Guido van Rossumf61f1662001-01-10 20:13:55 +00001373- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1374 subdirectory is no more!
1375
Tim Petersa3a3a032000-11-30 05:22:44 +00001376
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001377What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001378=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001379
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001380Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001381changes are in the file HISTORY. If you are making the jump directly
1382from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1383HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001384
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001385Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1386the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1387http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001388
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001389--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001390
1391======================================================================
1392
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001393What's new in 2.0 (since release candidate 1)?
1394==============================================
1395
1396Standard library
1397
1398- The copy_reg module was modified to clarify its intended use: to
1399 register pickle support for extension types, not for classes.
1400 pickle() will raise a TypeError if it is passed a class.
1401
1402- Fixed a bug in gettext's "normalize and expand" code that prevented
1403 it from finding an existing .mo file.
1404
1405- Restored support for HTTP/0.9 servers in httplib.
1406
Tim Peters989b7b92000-10-16 20:24:53 +00001407- The math module was changed to stop raising OverflowError in case of
1408 underflow, and return 0 instead in underflow cases. Whether Python
1409 used to raise OverflowError in case of underflow was platform-
1410 dependent (it did when the platform math library set errno to ERANGE
1411 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001412
1413- Fixed a bug in StringIO that occurred when the file position was not
1414 at the end of the file and write() was called with enough data to
1415 extend past the end of the file.
1416
1417- Fixed a bug that caused Tkinter error messages to get lost on
1418 Windows. The bug was fixed by replacing direct use of
1419 interp->result with Tcl_GetStringResult(interp).
1420
1421- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1422 redirect response.
1423
1424- Several changes were made to distutils: Some debugging code was
1425 removed from util. Fixed the installer used when an external zip
1426 program (like WinZip) is not found; the source code for this
1427 installer is in Misc/distutils. check_lib() was modified to behave
1428 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1429 test for whether installed modules are on sys.path was changed to
1430 use both normcase() and normpath().
1431
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001432- Several minor bugs were fixed in the xml package (the minidom,
1433 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001434
1435- The regression test driver (regrtest.py) behavior when invoked with
1436 -l changed: It now reports a count of objects that are recognized as
1437 garbage but not freed by the garbage collector.
1438
Tim Peters989b7b92000-10-16 20:24:53 +00001439- The regression test for the math module was changed to test
1440 exceptional behavior when the test is run in verbose mode. Python
1441 cannot yet guarantee consistent exception behavior across platforms,
1442 so the exception part of test_math is run only in verbose mode, and
1443 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001444
1445Internals
1446
1447- PyOS_CheckStack() has been disabled on Win64, where it caused
1448 test_sre to fail.
1449
1450Build issues
1451
1452- Changed compiler flags, so that gcc is always invoked with -Wall and
1453 -Wstrict-prototypes. Users compiling Python with GCC should see
1454 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001455 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001456 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001457
Tim Petersa3a3a032000-11-30 05:22:44 +00001458- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001459
1460Tools and other miscellany
1461
1462- The compiler in Tools/compiler was updated to support the new
1463 language features introduced in 2.0: extended print statement, list
1464 comprehensions, and augmented assignments. The new compiler should
1465 also be backwards compatible with Python 1.5.2; the compiler will
1466 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001467 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001468
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001469What's new in 2.0 release candidate 1 (since beta 2)?
1470=====================================================
1471
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001472What is release candidate 1?
1473
1474We believe that release candidate 1 will fix all known bugs that we
1475intend to fix for the 2.0 final release. This release should be a bit
1476more stable than the previous betas. We would like to see even more
1477widespread testing before the final release, so we are producing this
1478release candidate. The final release will be exactly the same unless
1479any show-stopping (or brown bag) bugs are found by testers of the
1480release candidate.
1481
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001482All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001483to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001484
1485Core language, builtins, and interpreter
1486
1487- A bug that caused crashes when __coerce__ was used with augmented
1488 assignment, e.g. +=, was fixed.
1489
1490- Raise ZeroDivisionError when raising zero to a negative number,
1491 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1492 power operator and the result of math.pow(0.0, -2.0) will vary by
1493 platform. On Linux, it raises a ValueError.
1494
1495- A bug in Unicode string interpolation was fixed that occasionally
1496 caused errors with formats including "%%". For example, the
1497 following expression "%% %s" % u"abc" no longer raises a TypeError.
1498
1499- Compilation of deeply nested expressions raises MemoryError instead
1500 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1501
1502- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1503 rendering them useless. They are now written in binary mode again.
1504
1505Standard library
1506
1507- Keyword arguments are now accepted for most pattern and match object
1508 methods in SRE, the standard regular expression engine.
1509
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001510- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001511 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001512
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001513- Several bugs in the Unicode handling and error handling in _tkinter
1514 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001515
1516- Fix memory management errors in Merge() and Tkapp_Call() routines.
1517
1518- Several changes were made to cStringIO to make it compatible with
1519 the file-like object interface and with StringIO. If operations are
1520 performed on a closed object, an exception is raised. The truncate
1521 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001522 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001523
1524- There were many changes made to the linuxaudiodev module and its
1525 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001526 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001527
1528 Note that this module is named poorly, because it should work
1529 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001530 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001531
1532 The module now raises exceptions when errors occur instead of
1533 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1534 audio) and defines a getptr() method that calls the
1535 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1536
1537- The library_version attribute, introduced in an earlier beta, was
1538 removed because it can not be supported with early versions of the C
1539 readline library, which provides no way to determine the version at
1540 compile-time.
1541
1542- The binascii module is now enabled on Win64.
1543
Tim Peters46446d62000-10-09 21:19:31 +00001544- tokenize.py no longer suffers "recursion depth" errors when parsing
1545 programs with very long string literals.
1546
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001547Internals
1548
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001549- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001550 which is called when the interpreter starts up to determine where
1551 the standard library is installed. These vulnerabilities affect all
1552 previous versions of Python and can be exploited by setting very
1553 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1554 setuid Python script, although use of the wrapper in
1555 Misc/setuid-prog.c will eliminate the vulnerability.
1556
1557- Fixed garbage collection bugs in instance creation that were
1558 triggered when errors occurred during initialization. The solution,
1559 applied in cPickle and in PyInstance_New(), is to call
1560 PyObject_GC_Init() after the initialization of the object's
1561 container attributes is complete.
1562
1563- pyexpat adds definitions of PyModule_AddStringConstant and
1564 PyModule_AddObject if the Python version is less than 2.0, which
1565 provides compatibility with PyXML on Python 1.5.2.
1566
1567- If the platform has a bogus definition for LONG_BIT (the number of
1568 bits in a long), an error will be reported at compile time.
1569
1570- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1571 collection crashes and possibly other, unreported crashes.
1572
1573- Fixed a memory leak in _PyUnicode_Fini().
1574
1575Build issues
1576
1577- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001578 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001579 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001580
1581- The mmap.PAGESIZE constant is now initialized using sysconf when
1582 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1583
1584- The md5 file should now compile on all platforms.
1585
1586- The select module now compiles on platforms that do not define
1587 POLLRDNORM and related constants.
1588
1589- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001590 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001591
Jeremy Hylton10921202000-10-09 18:34:12 +00001592- BeOS: A number of changes were made to the build and installation
1593 process. ar-fake now operates on a directory of object files.
1594 dl_export.h is gone, and its macros now appear on the mwcc command
1595 line during build on PPC BeOS.
1596
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001597- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001598 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001599
1600- Cygwin: Support for shared libraries, Tkinter, and sockets.
1601
1602- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1603
1604Tools and other miscellany
1605
1606- Removed debugging prints from main used with freeze.
1607
Tim Peters46446d62000-10-09 21:19:31 +00001608- IDLE auto-indent no longer crashes when it encounters Unicode
1609 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001610
1611What's new in 2.0 beta 2 (since beta 1)?
1612========================================
1613
1614Core language, builtins, and interpreter
1615
Tim Peters482c0212000-09-26 06:33:09 +00001616- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001617 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001618
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001619- Add -h and -V command line options to print the usage message and
1620 Python version number and exit immediately.
1621
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001622- eval() and exec accept Unicode objects as code parameters.
1623
1624- getattr() and setattr() now also accept Unicode objects for the
1625 attribute name, which are converted to strings using the default
1626 encoding before lookup.
1627
1628- Multiplication on string and Unicode now does proper bounds
1629 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1630 string is too long."
1631
1632- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001633 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001634
Jeremy Hylton1b618592000-09-26 05:32:36 +00001635
1636Standard library and extensions
1637
Guido van Rossum5b08f132001-04-16 02:05:23 +00001638- socket module: the OpenSSL code now adds support for RAND_status()
1639 and EGD (Entropy Gathering Device).
1640
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001641- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001642 argument checking; it still takes no arguments.
1643
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001644- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001645
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001646- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001647
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001648- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001649
1650- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001651 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001652
1653- copy: Copy Unicode objects atomically.
1654
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001655- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001656
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001657- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001658
Fred Drake67233bc2000-09-26 16:40:27 +00001659- dbm: Add get() and setdefault() methods to dbm object. Add constant
1660 `library' to module that names the library used. Added doc strings
1661 and method names to error messages. Uses configure to determine
1662 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1663 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001664
1665- distutils: Update to version 0.9.3.
1666
1667- dl: Add several dl.RTLD_ constants.
1668
1669- fpectl: Now supported on FreeBSD.
1670
1671- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1672 found by the collector will be saved in gc.garbage. This is useful
1673 for debugging a program that creates reference cycles.
1674
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001675- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001676 of HTTP class. Do not close socket on zero-length response. Do not
1677 crash when server sends invalid content-length header.
1678
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001679- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001680
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001681- marshal: When reading a short, sign-extend on platforms where shorts
1682 are bigger than 16 bits. When reading a long, repair the unportable
1683 sign extension that was being done for 64-bit machines. (It assumed
1684 that signed right shift sign-extends.)
1685
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001686- operator: Add contains(), invert(), __invert__() as aliases for
1687 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001688
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001689- os: Add support for popen2() and popen3() on all platforms where
1690 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001691
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001692- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001693 clicking on a file in Explorer (or passing the file name to the
1694 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001695
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001696- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001697 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001698
1699- pickle: Now raises ValueError when an invalid pickle that contains
1700 a non-string repr where a string repr was expected. This behavior
1701 matches cPickle.
1702
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001703- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001704
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001705- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001706
1707- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001708 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001709 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001710
1711- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001712 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001713
1714- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001715 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001716 few cycles during startup since the first call to
1717 setdefaultencoding() will initialize the codec registry and the
1718 encodings package.
1719
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001720- socket: Support for size hint in readlines() method of object returned
1721 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001722
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001723- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001724 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001725 is followed by whitespace.
1726
Tim Petersa3a3a032000-11-30 05:22:44 +00001727- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001728
1729- struct: Check ranges for bytes and shorts.
1730
1731- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001732 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001733
1734- Tkinter: Image objects are now guaranteed to have unique ids. Set
1735 event.delta to zero if Tk version doesn't support mousewheel.
1736 Removed some debugging prints.
1737
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001738- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001739
Fred Drake67233bc2000-09-26 16:40:27 +00001740- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001741 which works around a bug in Norton AntiVirus 2000 that leads directly
1742 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001743
1744- xml: New version detection code allows PyXML to override standard
1745 XML package if PyXML version is greater than 0.6.1.
1746
Fred Drake64bb3802000-09-26 16:21:35 +00001747- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1748 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1749 tree only for nodes which are sufficiently interesting to a specific
1750 application. Does not provide the HTML-specific extensions. Still
1751 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001752
Fred Drake64bb3802000-09-26 16:21:35 +00001753- xml.sax: SAX 2 support for Python, including all the handler
1754 interfaces needed to process XML 1.0 compliant XML. Some
1755 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001756
Fred Drake64bb3802000-09-26 16:21:35 +00001757- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1758 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001759
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001760
Jeremy Hylton1b618592000-09-26 05:32:36 +00001761C API
1762
1763- Add three new convenience functions for module initialization --
1764 PyModule_AddObject(), PyModule_AddIntConstant(), and
1765 PyModule_AddStringConstant().
1766
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001767- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001768 removed and add #error to Python.h if NULL isn't defined after
1769 #include of stdio.h.
1770
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001771- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001772 backwards compatibility (at the source level) with old extensions.
1773
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001774- A wrapper API was added for signal() and sigaction(). Instead of
1775 either function, always use PyOS_getsig() to get a signal handler
1776 and PyOS_setsig() to set one. A new convenience typedef
1777 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001778
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001779- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001780 internal data buffer and size of a string object -- or the default
1781 encoded version of a Unicode object.
1782
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001783- PyString_Size() and PyString_AsString() accept Unicode objects.
1784
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001785- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001786 exists). INT_MAX and LONG_MAX will always be defined, even if
1787 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001788
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001789- PyFloat_FromString takes a second argument, pend, that was
1790 effectively useless. It is now officially useless but preserved for
1791 backwards compatibility. If the pend argument is not NULL, *pend is
1792 set to NULL.
1793
1794- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1795 for the attribute name. See note on getattr() above.
1796
1797- A few bug fixes to argument processing for Unicode.
1798 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1799 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1800 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001801 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001802
1803- Py_BuildValue accepts B format (for bgen-generated code).
1804
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001805
Jeremy Hylton1b618592000-09-26 05:32:36 +00001806Internals
1807
1808- On Unix, fix code for finding Python installation directory so that
1809 it works when argv[0] is a relative path.
1810
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001811- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001812 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001813 rather than by generating a copy of the object.
1814
Tim Peters482c0212000-09-26 06:33:09 +00001815- Several of the internal Unicode tables are much smaller now, and
1816 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001817
Jeremy Hylton97693b02000-09-26 17:42:51 +00001818- In the garbage collector: Fixed bug in collection of tuples. Fixed
1819 bug that caused some instances to be removed from the container set
1820 while they were still live. Fixed parsing in gc.set_debug() for
1821 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001822
1823- Fixed refcount problem in instance deallocation that only occurred
1824 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1825
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001826- On Windows, getpythonregpath is now protected against null data in
1827 registry key.
1828
1829- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001830 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001831
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001832
Jeremy Hylton1b618592000-09-26 05:32:36 +00001833Build and platform-specific issues
1834
1835- Better support of GNU Pth via --with-pth configure option.
1836
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001837- Python/C API now properly exposed to dynamically-loaded extension
1838 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001839
1840- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1841 Don't define MS_SYNC to be zero when it is undefined. Added missing
1842 prototypes in posixmodule.c.
1843
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001844- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001845 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001846
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001847- Fix largefile support on older NetBSD systems and OpenBSD by adding
1848 define for TELL64.
1849
1850
1851Tools and other miscellany
1852
1853- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1854
1855- freeze: The modulefinder now works with 2.0 opcodes.
1856
Tim Petersa3a3a032000-11-30 05:22:44 +00001857- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001858 Move hackery of sys.argv until after the Tk instance has been
1859 created, which allows the application-specific Tkinter
1860 initialization to be executed if present; also pass an explicit
1861 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001862
Jeremy Hylton1b618592000-09-26 05:32:36 +00001863
1864What's new in 2.0 beta 1?
1865=========================
1866
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001867Source Incompatibilities
1868------------------------
1869
1870None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1871such as single-argument append(), connect() and bind(), and changes to
1872str(long) and repr(float).
1873
1874
1875Binary Incompatibilities
1876------------------------
1877
1878- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1879with Python 2.0; these extensions will have to be rebuilt for Python
18802.0.
1881
1882- On Windows, attempting to import a third party extension built for
1883Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1884can do about this. Check your PYTHONPATH environment variable!
1885
1886- Python bytecode files (*.pyc and *.pyo) are not compatible between
1887releases.
1888
1889
1890Overview of Changes Since 1.6
1891-----------------------------
1892
1893There are many new modules (including brand new XML support through
1894the xml package, and i18n support through the gettext module); a list
1895of all new modules is included below. Lots of bugs have been fixed.
1896
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001897The process for making major new changes to the language has changed
1898since Python 1.6. Enhancements must now be documented by a Python
1899Enhancement Proposal (PEP) before they can be accepted.
1900
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001901There are several important syntax enhancements, described in more
1902detail below:
1903
1904 - Augmented assignment, e.g. x += 1
1905
1906 - List comprehensions, e.g. [x**2 for x in range(10)]
1907
1908 - Extended import statement, e.g. import Module as Name
1909
1910 - Extended print statement, e.g. print >> file, "Hello"
1911
1912Other important changes:
1913
1914 - Optional collection of cyclical garbage
1915
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001916Python Enhancement Proposal (PEP)
1917---------------------------------
1918
1919PEP stands for Python Enhancement Proposal. A PEP is a design
1920document providing information to the Python community, or describing
1921a new feature for Python. The PEP should provide a concise technical
1922specification of the feature and a rationale for the feature.
1923
1924We intend PEPs to be the primary mechanisms for proposing new
1925features, for collecting community input on an issue, and for
1926documenting the design decisions that have gone into Python. The PEP
1927author is responsible for building consensus within the community and
1928documenting dissenting opinions.
1929
1930The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001931
1932Augmented Assignment
1933--------------------
1934
1935This must have been the most-requested feature of the past years!
1936Eleven new assignment operators were added:
1937
Guido van Rossume905e952000-09-05 12:42:46 +00001938 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001939
1940For example,
1941
1942 A += B
1943
1944is similar to
1945
1946 A = A + B
1947
1948except that A is evaluated only once (relevant when A is something
1949like dict[index].attr).
1950
1951However, if A is a mutable object, A may be modified in place. Thus,
1952if A is a number or a string, A += B has the same effect as A = A+B
1953(except A is only evaluated once); but if a is a list, A += B has the
1954same effect as A.extend(B)!
1955
1956Classes and built-in object types can override the new operators in
1957order to implement the in-place behavior; the not-in-place behavior is
1958used automatically as a fallback when an object doesn't implement the
1959in-place behavior. For classes, the method name is derived from the
1960method name for the corresponding not-in-place operator by inserting
1961an 'i' in front of the name, e.g. __iadd__ implements in-place
1962__add__.
1963
1964Augmented assignment was implemented by Thomas Wouters.
1965
1966
1967List Comprehensions
1968-------------------
1969
1970This is a flexible new notation for lists whose elements are computed
1971from another list (or lists). The simplest form is:
1972
1973 [<expression> for <variable> in <sequence>]
1974
Guido van Rossum56db0952000-09-06 23:34:25 +00001975For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001976This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001977
1978You can also add a condition:
1979
1980 [<expression> for <variable> in <sequence> if <condition>]
1981
1982For example, [w for w in words if w == w.lower()] would yield the list
1983of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001984than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001985
1986You can also have nested for loops and more than one 'if' clause. For
1987example, here's a function that flattens a sequence of sequences::
1988
1989 def flatten(seq):
1990 return [x for subseq in seq for x in subseq]
1991
1992 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1993
1994This prints
1995
1996 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1997
1998List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001999Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002000
2001
2002Extended Import Statement
2003-------------------------
2004
2005Many people have asked for a way to import a module under a different
2006name. This can be accomplished like this:
2007
2008 import foo
2009 bar = foo
2010 del foo
2011
2012but this common idiom gets old quickly. A simple extension of the
2013import statement now allows this to be written as follows:
2014
2015 import foo as bar
2016
2017There's also a variant for 'from ... import':
2018
2019 from foo import bar as spam
2020
2021This also works with packages; e.g. you can write this:
2022
2023 import test.regrtest as regrtest
2024
2025Note that 'as' is not a new keyword -- it is recognized only in this
2026context (this is only possible because the syntax for the import
2027statement doesn't involve expressions).
2028
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002029Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002030
2031
2032Extended Print Statement
2033------------------------
2034
2035Easily the most controversial new feature, this extension to the print
2036statement adds an option to make the output go to a different file
2037than the default sys.stdout.
2038
2039For example, to write an error message to sys.stderr, you can now
2040write:
2041
2042 print >> sys.stderr, "Error: bad dog!"
2043
2044As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002045evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002046
2047 print >> None, "Hello world"
2048
2049is equivalent to
2050
2051 print "Hello world"
2052
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002053Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002054
2055
2056Optional Collection of Cyclical Garbage
2057---------------------------------------
2058
2059Python is now equipped with a garbage collector that can hunt down
2060cyclical references between Python objects. It's no replacement for
2061reference counting; in fact, it depends on the reference counts being
2062correct, and decides that a set of objects belong to a cycle if all
2063their reference counts can be accounted for from their references to
2064each other. This devious scheme was first proposed by Eric Tiedemann,
2065and brought to implementation by Neil Schemenauer.
2066
2067There's a module "gc" that lets you control some parameters of the
2068garbage collection. There's also an option to the configure script
2069that lets you enable or disable the garbage collection. In 2.0b1,
2070it's on by default, so that we (hopefully) can collect decent user
2071experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002072performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002073off by default in the final 2.0 release.
2074
2075
2076Smaller Changes
2077---------------
2078
2079A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2080map(None, seq1, seq2, ...) when the sequences have the same length;
2081i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2082the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002083zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002084
2085sys.version_info is a tuple (major, minor, micro, level, serial).
2086
2087Dictionaries have an odd new method, setdefault(key, default).
2088dict.setdefault(key, default) returns dict[key] if it exists; if not,
2089it sets dict[key] to default and returns that value. Thus:
2090
2091 dict.setdefault(key, []).append(item)
2092
2093does the same work as this common idiom:
2094
2095 if not dict.has_key(key):
2096 dict[key] = []
2097 dict[key].append(item)
2098
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002099There are two new variants of SyntaxError that are raised for
2100indentation-related errors: IndentationError and TabError.
2101
2102Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2103escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002104
2105The limits on the size of expressions and file in Python source code
2106have been raised from 2**16 to 2**32. Previous versions of Python
2107were limited because the maximum argument size the Python VM accepted
2108was 2**16. This limited the size of object constructor expressions,
2109e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2110limit was raised thanks to a patch by Charles Waldman that effectively
2111fixes the problem. It is now much more likely that you will be
2112limited by available memory than by an arbitrary limit in Python.
2113
2114The interpreter's maximum recursion depth can be modified by Python
2115programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2116limit is the maximum number of recursive calls that can be made by
2117Python code. The limit exists to prevent infinite recursion from
2118overflowing the C stack and causing a core dump. The default value is
21191000. The maximum safe value for a particular platform can be found
2120by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002121
2122New Modules and Packages
2123------------------------
2124
2125atexit - for registering functions to be called when Python exits.
2126
2127imputil - Greg Stein's alternative API for writing custom import
2128hooks.
2129
2130pyexpat - an interface to the Expat XML parser, contributed by Paul
2131Prescod.
2132
2133xml - a new package with XML support code organized (so far) in three
2134subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2135would fill a volume. There's a special feature whereby a
2136user-installed package named _xmlplus overrides the standard
2137xmlpackage; this is intended to give the XML SIG a hook to distribute
2138backwards-compatible updates to the standard xml package.
2139
2140webbrowser - a platform-independent API to launch a web browser.
2141
2142
Guido van Rossume905e952000-09-05 12:42:46 +00002143Changed Modules
2144---------------
2145
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002146array -- new methods for array objects: count, extend, index, pop, and
2147remove
2148
2149binascii -- new functions b2a_hex and a2b_hex that convert between
2150binary data and its hex representation
2151
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002152calendar -- Many new functions that support features including control
2153over which day of the week is the first day, returning strings instead
2154of printing them. Also new symbolic constants for days of week,
2155e.g. MONDAY, ..., SUNDAY.
2156
2157cgi -- FieldStorage objects have a getvalue method that works like a
2158dictionary's get method and returns the value attribute of the object.
2159
2160ConfigParser -- The parser object has new methods has_option,
2161remove_section, remove_option, set, and write. They allow the module
2162to be used for writing config files as well as reading them.
2163
2164ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002165optionally support the RFC 959 REST command.
2166
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002167gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002168
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002169httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2170the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002171
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002172locale -- implement getdefaultlocale for Win32 and Macintosh
2173
2174marshal -- no longer dumps core when marshaling deeply nested or
2175recursive data structures
2176
2177os -- new functions isatty, seteuid, setegid, setreuid, setregid
2178
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002179os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2180support under Unix.
2181
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002182os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002183
2184os.path -- fix semantics of os.path.commonprefix
2185
2186smtplib -- support for sending very long messages
2187
2188socket -- new function getfqdn()
2189
2190readline -- new functions to read, write and truncate history files.
2191The readline section of the library reference manual contains an
2192example.
2193
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002194select -- add interface to poll system call
2195
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002196shutil -- new copyfileobj function
2197
2198SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2199HTTP server.
2200
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002201Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002202
2203urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002204e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002205
2206whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002207
2208
2209Obsolete Modules
2210----------------
2211
2212None. However note that 1.6 made a whole slew of modules obsolete:
2213stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2214poly, zmod, strop, util, whatsound.
2215
2216
2217Changed, New, Obsolete Tools
2218----------------------------
2219
Tim Peters8b092332000-09-05 20:15:25 +00002220None.
Guido van Rossume905e952000-09-05 12:42:46 +00002221
2222
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002223C-level Changes
2224---------------
2225
2226Several cleanup jobs were carried out throughout the source code.
2227
2228All C code was converted to ANSI C; we got rid of all uses of the
2229Py_PROTO() macro, which makes the header files a lot more readable.
2230
2231Most of the portability hacks were moved to a new header file,
2232pyport.h; several other new header files were added and some old
2233header files were removed, in an attempt to create a more rational set
2234of header files. (Few of these ever need to be included explicitly;
2235they are all included by Python.h.)
2236
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002237Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002238and Win64, especially for the new Intel Itanium processor. Mick also
2239added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002240
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002241The C APIs to return an object's size have been update to consistently
2242use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2243previous versions, the abstract interfaces used PyXXX_Length and the
2244concrete interfaces used PyXXX_Size. The old names,
2245e.g. PyObject_Length, are still available for backwards compatibility
2246at the API level, but are deprecated.
2247
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002248The PyOS_CheckStack function has been implemented on Windows by
2249Fredrik Lundh. It prevents Python from failing with a stack overflow
2250on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002251
2252The GC changes resulted in creation of two new slots on object,
2253tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002254the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002255
2256The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002257C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002258
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002259PyErr_Format has been updated to automatically calculate the size of
2260the buffer needed to hold the formatted result string. This change
2261prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002262
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002263New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002264
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002265PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2266that are the same as their non-Ex counterparts except they take an
2267extra flag argument that tells them to close the file when done.
2268
2269XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002270
Tim Peters8b092332000-09-05 20:15:25 +00002271
2272Windows Changes
2273---------------
2274
2275New popen2/popen3/peopen4 in os module (see Changed Modules above).
2276
2277os.popen is much more usable on Windows 95 and 98. See Microsoft
2278Knowledge Base article Q150956. The Win9x workaround described there
2279is implemented by the new w9xpopen.exe helper in the root of your
2280Python installation. Note that Python uses this internally; it is not
2281a standalone program.
2282
2283Administrator privileges are no longer required to install Python
2284on Windows NT or Windows 2000. If you have administrator privileges,
2285Python's registry info will be written under HKEY_LOCAL_MACHINE.
2286Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002287under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002288uses of Python, but will prevent some advanced uses from working
2289(for example, running a Python script as an NT service, or possibly
2290from CGI).
2291
2292[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2293installer; instead, it installs the needed Tcl/Tk files directly in the
2294Python directory. If you already have a Tcl/Tk installation, this
2295wastes some disk space (about 4 Megs) but avoids problems with
2296conflicting Tcl/Tk installations, and makes it much easier for Python
2297to ensure that Tcl/Tk can find all its files.
2298
2299[This was new in 1.6] The Windows installer now installs by default in
2300\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2301
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002302
2303Updates to the changes between 1.5.2 and 1.6
2304--------------------------------------------
2305
2306The 1.6 NEWS file can't be changed after the release is done, so here
2307is some late-breaking news:
2308
2309New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2310and changes to getlocale() and setlocale().
2311
2312The new module is now enabled per default.
2313
2314It is not true that the encodings codecs cannot be used for normal
2315strings: the string.encode() (which is also present on 8-bit strings
2316!) allows using them for 8-bit strings too, e.g. to convert files from
2317cp1252 (Windows) to latin-1 or vice-versa.
2318
2319Japanese codecs are available from Tamito KAJIYAMA:
2320http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2321
2322
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002323======================================================================