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Tim Petersb07352e2001-09-08 01:25:47 +00001What's New in Python 2.2a4?
2===========================
3
4Core
5
6Library
7
8Tools
9
10Build
11
12C API
13
14New platforms
15
16Tests
17
18Windows
19
20
Tim Petersedc99312001-08-22 21:36:50 +000021What's New in Python 2.2a3?
22===========================
23
24Core
25
Tim Peters9fffa3e2001-09-04 05:14:19 +000026- Conversion of long to float now raises OverflowError if the long is too
27 big to represent as a C double.
28
Tim Peters32f453e2001-09-03 08:35:41 +000029- The 3-argument builtin pow() no longer allows a third non-None argument
30 if either of the first two arguments is a float, or if both are of
31 integer types and the second argument is negative (in which latter case
32 the arguments are converted to float, so this is really the same
33 restriction).
34
Tim Peters5d2b77c2001-09-03 05:47:38 +000035- The builtin dir() now returns more information, and sometimes much
36 more, generally naming all attributes of an object, and all attributes
37 reachable from the object via its class, and from its class's base
38 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
39 an empty list. In 2.2a3,
40
41 >>> dir([])
42 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
43 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
44 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
45 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
46 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
47 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
48 'reverse', 'sort']
49
50 dir(module) continues to return only the module's attributes, though.
51
Tim Petersbdee63f2001-09-02 03:40:59 +000052- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +000053 than raising OverflowError. This is a partial implementation of PEP
54 237. You can use -Wdefault::OverflowWarning to enable a warning for
55 this situation, and -Werror::OverflowWarning to revert to the old
56 OverflowError exception.
57
Guido van Rossum61c345f2001-09-04 03:26:15 +000058- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +000059 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +000060 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
61 -Qold, meaning the / operator has its classic meaning and no
62 warnings are issued. Using -Qwarn issues a run-time warning about
63 all uses of classic division for int and long arguments; -Qwarnall
64 also warns about classic division for float and complex arguments
65 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
66 new division by default, but only in the __main__ module. You can
67 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
68 __main__ module new division, and warns about classic division
69 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +000070
Tim Petersbdee63f2001-09-02 03:40:59 +000071- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +000072 long, float, str, unicode, and tuple. (The types complex, list and
73 dictionary can also be subclassed; this was introduced earlier.)
74 Note that restrictions apply when subclassing immutable built-in
75 types: you can only affect the value of the instance by overloading
76 __new__. You can add mutable attributes, and the subclass instances
77 will have a __dict__ attribute, but you cannot change the "value"
78 (as implemented by the base class) of an immutable subclass instance
79 once it is created.
80
Guido van Rossumaaf80c82001-09-02 13:44:35 +000081- The dictionary constructor now takes an optional argument, a
82 mapping-like object, and initializes the dictionary from its
83 (key, value) pairs.
84
Tim Petersbdee63f2001-09-02 03:40:59 +000085- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +000086 "cooperative super calls" in a multiple inheritance setting. For an
87 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
88
Guido van Rossum8d7234d2001-09-06 22:02:58 +000089- A new built-in type, property, has been added. This enables the
90 creation of "properties". These are attributes implemented by
91 getter and setter functions (or only one of these for read-only or
92 write-only attributes), without the need to override __getattr__.
93 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +000094
Tim Petersbdee63f2001-09-02 03:40:59 +000095- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +000096 liberalized, to allow leading zeroes. Examples of literals now
97 legal that were SyntaxErrors before:
98
99 00.0 0e3 0100j 07.5 00000000000000000008.
100
Tim Petersbdee63f2001-09-02 03:40:59 +0000101- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000102 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
103
Tim Petersedc99312001-08-22 21:36:50 +0000104Library
105
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000106- telnetlib includes symbolic names for the options, and support for
107 setting an option negotiation callback.
108
Tim Petersa40c7932001-09-05 22:36:56 +0000109- The new C standard no longer requires that math libraries set errno to
110 ERANGE on overflow. For platform libraries that exploit this new
111 freedom, Python's overflow-checking was wholly broken. A new overflow-
112 checking scheme attempts to repair that, but may not be reliable on all
113 platforms (C doesn't seem to provide anything both useful and portable
114 in this area anymore).
115
Martin v. Löwis44f86962001-09-05 13:44:54 +0000116- Asynchronous timeout actions are available through the new class
117 threading.Timer.
118
Tim Peters78526162001-09-05 00:53:45 +0000119- math.log and math.log10 now return sensible results for even huge
120 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
121
Tim Petersbdee63f2001-09-02 03:40:59 +0000122- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000123 currently held. See the docs for the imp module.
124
Tim Petersbdee63f2001-09-02 03:40:59 +0000125- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000126 dumps containing ints written on platforms where Python ints are 8 bytes.
127 When read on a box where Python ints are 4 bytes, such values are
128 converted to Python longs.
129
Tim Petersbdee63f2001-09-02 03:40:59 +0000130- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000131 code objects is no longer allowed. This plugs a security hole.
132
Steve Purcell6091cd62001-09-06 16:05:17 +0000133- unittest.TestResult instances no longer store references to tracebacks
134 generated by test failures. This prevents unexpected dangling references
135 to objects that should be garbage collected between tests.
136
Tim Petersedc99312001-08-22 21:36:50 +0000137Tools
138
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000139- Tools/scripts/fixdiv.py has been added which can be used to fix
140 division operators as per PEP 238.
141
Tim Petersedc99312001-08-22 21:36:50 +0000142Build
143
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000144- If you are an adventurous person using Mac OS X you may want to look at
145 Mac/OSX. There is a Makefile there that will build Python as a real Mac
146 application, which can be used for experimenting with Carbon or Cocoa.
147 Discussion of this on pythonmac-sig, please.
148
Tim Peters7eea37e2001-09-04 22:08:56 +0000149C API
150
151- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000152
Tim Peters9fffa3e2001-09-04 05:14:19 +0000153- Note that PyLong_AsDouble can fail! This has always been true, but no
154 callers checked for it. It's more likely to fail now, because overflow
155 errors are properly detected now. The proper way to check:
156
157 double x = PyLong_AsDouble(some_long_object);
158 if (x == -1.0 && PyErr_Occurred()) {
159 /* The conversion failed. */
160 }
161
Tim Petersbdee63f2001-09-02 03:40:59 +0000162- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000163 compile but will not participate in GC. To upgrade an extension
164 module:
165
166 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000167
Neil Schemenauer4042c692001-08-30 15:38:01 +0000168 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
169 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000170
Neil Schemenauer4042c692001-08-30 15:38:01 +0000171 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
172 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000173
Neil Schemenauer4042c692001-08-30 15:38:01 +0000174 - remove PyGC_HEAD_SIZE from object size calculations
175
176 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
177
Tim Petersbdee63f2001-09-02 03:40:59 +0000178- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000179 These can be used safely to construct string objects from a
180 sprintf-style format string (similar to the format string supported
181 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000182
Tim Petersedc99312001-08-22 21:36:50 +0000183New platforms
184
Tim Petersb7da0902001-09-02 23:01:43 +0000185- Stephen Hansen contributed patches sufficient to get a clean compile
186 under Borland C (Windows), but he reports problems running it and ran
187 out of time to complete the port. Volunteers? Expect a MemoryError
188 when importing the types module; this is probably shallow, and
189 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000190
Tim Petersedc99312001-08-22 21:36:50 +0000191Tests
192
193Windows
194
Tim Peters6e13a562001-09-06 00:32:15 +0000195- Large file support is now enabled on Win32 platforms as well as on
196 Win64. This means that, for example, you can use f.tell() and f.seek()
197 to manipulate files larger than 2 gigabytes (provided you have enough
198 disk space, and are using a Windows filesystem that supports large
199 partitions).
200
Tim Petersbdee63f2001-09-02 03:40:59 +0000201- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000202 points to command.com (patch from Brian Quinlan).
203
Tim Petersedc99312001-08-22 21:36:50 +0000204
Tim Peters20f51a72001-07-21 02:31:40 +0000205What's New in Python 2.2a2?
206===========================
207
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000208Build
209
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000210- Tim Peters developed a brand new Windows installer using Wise 8.1,
211 generously donated to us by Wise Solutions.
212
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000213- configure supports a new option --enable-unicode, with the values
214 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
215 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000216
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000217- A new configure option --enable-framework builds a Mac OS X framework,
218 which "make frameworkinstall" will install. This provides a starting
219 point for more mac-like functionality, join pythonmac-sig@python.org
220 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000221
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000222- The NeXT platform is no longer supported.
223
224- The `new' module is now statically linked.
225
Tim Peters0afb6092001-08-15 06:06:44 +0000226Tools
227
228- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000229 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000230 the module docstring for details.
231
Tim Peters20f51a72001-07-21 02:31:40 +0000232Tests
233
Tim Peters5e824c32001-08-12 22:25:01 +0000234- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000235 platforms, allowing to give clearer test result output. regrtest
236 also has optional --use/-u switch to run normally disabled tests
237 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000238
Tim Peters20f51a72001-07-21 02:31:40 +0000239- Several new tests in the standard test suite, with special thanks to
240 Nick Mathewson.
241
242Core
243
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000244- The floor division operator // has been added as outlined in PEP
245 238. The / operator still provides classic division (and will until
246 Python 3.0) unless "from __future__ import division" is included, in
247 which case the / operator will provide true division. The operator
248 module provides truediv() and floordiv() functions. Augmented
249 assignment variants are included, as are the equivalent overloadable
250 methods and C API methods. See the PEP for a full discussion:
251 <http://python.sf.net/peps/pep-0238.html>
252
Tim Peters6cd6a822001-08-17 22:11:27 +0000253- Future statements are now effective in simulated interactive shells
254 (like IDLE). This should "just work" by magic, but read Michael
255 Hudson's "Future statements in simulated shells" PEP 264 for full
256 details: <http://python.sf.net/peps/pep-0264.html>.
257
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000258- The type/class unification (PEP 252-253) was integrated into the
259 trunk and is not so tentative any more (the exact specification of
260 some features is still tentative). A lot of work has done on fixing
261 bugs and adding robustness and features (performance still has to
262 come a long way).
263
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000264- Warnings about a mismatch in the Python API during extension import
265 now use the Python warning framework (which makes it possible to
266 write filters for these warnings).
267
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000268- A function's __dict__ (aka func_dict) will now always be a
269 dictionary. It used to be possible to delete it or set it to None,
270 but now both actions raise TypeErrors. It is still legal to set it
271 to a dictionary object. Getting func.__dict__ before any attributes
272 have been assigned now returns an empty dictionary instead of None.
273
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000274- A new command line option, -E, was added which disables the use of
275 all environment variables, or at least those that are specifically
276 significant to Python. Usually those have a name starting with
277 "PYTHON". This was used to fix a problem where the tests fail if
278 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
279 older distribution.
280
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000281Library
282
Tim Peters5e824c32001-08-12 22:25:01 +0000283- New class Differ and new functions ndiff() and restore() in difflib.py.
284 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000285 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000286
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000287- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
288 value using the minimal quoting required for the value; more
289 reliable than using xml.sax.saxutils.escape() for attribute values.
290
291- Readline completion support for cmd.Cmd was added.
292
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000293- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
294
295- Added function threading.BoundedSemaphore()
296
297- Added Ka-Ping Yee's cgitb.py module.
298
299- The `new' module now exposes the CO_xxx flags.
300
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000301New platforms
302
303C API
304
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000305- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
306 which provide a cross-platform implementations for the
307 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
308 the standard sprintf() and vsprintf() C lib APIs, these versions
309 apply bounds checking on the used buffer which enhances protection
310 against buffer overruns.
311
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000312- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000313 and extensions using different Unicode widths is rendered next to
314 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000315 will result in an ImportError. Unicode extensions writers must make
316 sure to check the Unicode width compatibility in their extensions by
317 using at least one of the mangled Unicode APIs in the extension.
318
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000319- Two new flags METH_NOARGS and METH_O are available in method definition
320 tables to simplify implementation of methods with no arguments and a
321 single untyped argument. Calling such methods is more efficient than
322 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
323 deprecated.
324
Tim Petersc1731372001-08-04 08:12:36 +0000325Windows
326
327- "import module" now compiles module.pyw if it exists and nothing else
328 relevant is found.
329
Tim Peters20f51a72001-07-21 02:31:40 +0000330
Guido van Rossum55a78992001-07-17 17:22:32 +0000331What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000332===========================
333
334Core
Tim Petersa814db52001-05-14 07:05:58 +0000335
Tim Peters6d6c1a32001-08-02 04:15:00 +0000336- TENTATIVELY, a large amount of code implementing much of what's
337 described in PEP 252 (Making Types Look More Like Classes) and PEP
338 253 (Subtyping Built-in Types) was added. This will be released
339 with Python 2.2a1. Documentation will be provided separately
340 through http://www.python.org/2.2/. The purpose of releasing this
341 with Python 2.2a1 is to test backwards compatibility. It is
342 possible, though not likely, that a decision is made not to release
343 this code as part of 2.2 final, if any serious backwards
344 incompapatibilities are found during alpha testing that cannot be
345 repaired.
346
Guido van Rossum55a78992001-07-17 17:22:32 +0000347- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000348 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000349 more 'yield' statements. See PEP 255. Since this adds a new
350 keyword to the language, this feature must be enabled by including a
351 future statement: "from __future__ import generators" (see PEP 236).
352 Generators will become a standard feature in a future release
353 (probably 2.3). Without this future statement, 'yield' remains an
354 ordinary identifier, but a warning is issued each time it is used.
355 (These warnings currently don't conform to the warnings framework of
356 PEP 230; we intend to fix this in 2.2a2.)
357
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000358- The UTF-16 codec was modified to be more RFC compliant. It will now
359 only remove BOM characters at the start of the string and then
360 only if running in native mode (UTF-16-LE and -BE won't remove a
361 leading BMO character).
362
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000363- Strings now have a new method .decode() to complement the already
364 existing .encode() method. These two methods provide direct access
365 to the corresponding decoders and encoders of the registered codecs.
366
367 To enhance the usability of the .encode() method, the special
368 casing of Unicode object return values was dropped (Unicode objects
369 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000370
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000371 Both methods will now return whatever the codec in charge of the
372 requested encoding returns as object, e.g. Unicode codecs will
373 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
374 will return u"äöü"). This enables codec writer to create codecs
375 for various simple to use conversions.
376
377 New codecs were added to demonstrate these new features (the .encode()
378 and .decode() columns indicate the type of the returned objects):
379
380 Name | .encode() | .decode() | Description
381 ----------------------------------------------------------------------
382 uu | string | string | UU codec (e.g. for email)
383 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000384 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000385 zlib | string | string | zlib compression
386 hex | string | string | 2-byte hex codec
387 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
388
Mark Hammond2a0af792001-05-14 03:09:36 +0000389- Some operating systems now support the concept of a default Unicode
390 encoding for file system operations. Notably, Windows supports 'mbcs'
391 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000392 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000393 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000394
395 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000396 functions that return filenames (such as os.listdir()) to return Python
397 string objects pre-encoded using the default file system encoding for
398 the platform. As this encoding is likely to be different from Python's
399 default encoding, converting this name to a Unicode object before passing
400 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000401 would attempt to use its default encoding (generally ASCII) rather than
402 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000403
Tim Petersa814db52001-05-14 07:05:58 +0000404 In general, this change simply removes surprises when working with
405 Unicode and the file system, making these operations work as you expect,
406 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000407 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000408
Tim Peters61dff2b2001-05-08 15:43:37 +0000409- Float (and complex) literals in source code were evaluated to full
410 precision only when running from a .py file; the same code loaded from a
411 .pyc (or .pyo) file could suffer numeric differences starting at about the
412 12th significant decimal digit. For example, on a machine with IEEE-754
413 floating arithmetic,
414
415 x = 9007199254740992.0
416 print long(x)
417
418 printed 9007199254740992 if run directly from .py, but 9007199254740000
419 if from a compiled (.pyc or .pyo) file. This was due to marshal using
420 str(float) instead of repr(float) when building code objects. marshal
421 now uses repr(float) instead, which should reproduce floats to full
422 machine precision (assuming the platform C float<->string I/O conversion
423 functions are of good quality).
424
425 This may cause floating-point results to change in some cases, and
426 usually for the better, but may also cause numerically unstable
427 algorithms to break.
428
Tim Peters2f228e72001-05-13 00:19:31 +0000429- The implementation of dicts suffers fewer collisions, which has speed
430 benefits. However, the order in which dict entries appear in dict.keys(),
431 dict.values() and dict.items() may differ from previous releases for a
432 given dict. Nothing is defined about this order, so no program should
433 rely on it. Nevertheless, it's easy to write test cases that rely on the
434 order by accident, typically because of printing the str() or repr() of a
435 dict to an "expected results" file. See Lib/test/test_support.py's new
436 sortdict(dict) function for a simple way to display a dict in sorted
437 order.
438
Tim Peters7a3bfc32001-06-12 01:22:22 +0000439- Many other small changes to dicts were made, resulting in faster
440 operation along the most common code paths.
441
Guido van Rossum10315822001-05-01 20:54:30 +0000442- Dictionary objects now support the "in" operator: "x in dict" means
443 the same as dict.has_key(x).
444
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000445- The update() method of dictionaries now accepts generic mapping
446 objects. Specifically the argument object must support the .keys()
447 and __getitem__() methods. This allows you to say, for example,
448 {}.update(UserDict())
449
Guido van Rossum10315822001-05-01 20:54:30 +0000450- Iterators were added; this is a generalized way of providing values
451 to a for loop. See PEP 234. There's a new built-in function iter()
452 to return an iterator. There's a new protocol to get the next value
453 from an iterator using the next() method (in Python) or the
454 tp_iternext slot (in C). There's a new protocol to get iterators
455 using the __iter__() method (in Python) or the tp_iter slot (in C).
456 Iterating (i.e. a for loop) over a dictionary generates its keys.
457 Iterating over a file generates its lines.
458
Tim Petersf553f892001-05-01 20:45:31 +0000459- The following functions were generalized to work nicely with iterator
460 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000461 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000462 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
463 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000464 join() method of strings
465 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000466 'x in y' and 'x not in y' (PySequence_Contains() in C API)
467 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000468 right-hand side of assignment statements with multiple targets, such as
469 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000470
Tim Petersd85e1022001-05-11 21:51:48 +0000471- Accessing module attributes is significantly faster (for example,
472 random.random or os.path or yourPythonModule.yourAttribute).
473
Tim Peterse63415e2001-05-08 04:38:29 +0000474- Comparing dictionary objects via == and != is faster, and now works even
475 if the keys and values don't support comparisons other than ==.
476
Tim Peters95bf9392001-05-10 08:32:44 +0000477- Comparing dictionaries in ways other than == and != is slower: there were
478 insecurities in the dict comparison implementation that could cause Python
479 to crash if the element comparison routines for the dict keys and/or
480 values mutated the dicts. Making the code bulletproof slowed it down.
481
Tim Peterseb28ef22001-06-02 05:27:19 +0000482- Collisions in dicts are resolved via a new approach, which can help
483 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000484 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000485 faster now. Thanks to Christian Tismer for pointing out the cause and
486 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000487
Tim Peters52e155e2001-06-16 05:42:57 +0000488- repr() is much faster for large containers (dict, list, tuple).
489
490
Tim Petersa814db52001-05-14 07:05:58 +0000491Library
492
Fred Drake960fdf92001-07-20 18:38:26 +0000493- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
494 were added to the string module. These a locale-indenpendent
495 constants, unlike letters, lowercase, and uppercase. These are now
496 use in appropriate locations in the standard library.
497
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000498- The flags used in dlopen calls can now be configured using
499 sys.setdlopenflags and queried using sys.getdlopenflags.
500
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000501- Fredrik Lundh's xmlrpclib is now a standard library module. This
502 provides full client-side XML-RPC support. In addition,
503 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
504 one asyncore-based). Thanks to Eric Raymond for the documentation.
505
Guido van Rossum643d3912001-07-05 14:46:25 +0000506- The xrange() object is simplified: it no longer supports slicing,
507 repetition, comparisons, efficient 'in' checking, the tolist()
508 method, or the start, stop and step attributes. See PEP 260.
509
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000510- A new function fnmatch.filter to filter lists of file names was added.
511
Barry Warsawffd674d2001-05-22 16:00:10 +0000512- calendar.py uses month and day names based on the current locale.
513
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000514- strop is now *really* obsolete (this was announced before with 1.6),
515 and issues DeprecationWarning when used (except for the four items
516 that are still imported into string.py).
517
Tim Petersa814db52001-05-14 07:05:58 +0000518- Cookie.py now sorts key+value pairs by key in output strings.
519
520- pprint.isrecursive(object) didn't correctly identify recursive objects.
521 Now it does.
522
Tim Peters95b3f782001-05-14 18:39:41 +0000523- pprint functions now much faster for large containers (tuple, list, dict).
524
Tim Peters7b9542a2001-06-10 23:40:19 +0000525- New 'q' and 'Q' format codes in the struct module, corresponding to C
526 types "long long" and "unsigned long long" (on Windows, __int64). In
527 native mode, these can be used only when the platform C compiler supports
528 these types (when HAVE_LONG_LONG is #define'd by the Python config
529 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000530 In standard mode, 'q' and 'Q' are supported on all platforms, and are
531 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000532
Guido van Rossum83213cc2001-06-12 16:48:52 +0000533- The site module installs a new built-in function 'help' that invokes
534 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
535 it displays a message reminding the user to use 'help()' or
536 'help(object)'.
537
Tim Petersa814db52001-05-14 07:05:58 +0000538Tests
539
540- New test_mutants.py runs dict comparisons where the key and value
541 comparison operators mutute the dicts randomly during comparison. This
542 rapidly causes Python to crash under earlier releases (not for the faint
543 of heart: it can also cause Win9x to freeze or reboot!).
544
545- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000546 pprint.isreadable() return sensible results. Also verifies that simple
547 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000548
Tim Peters4324aa32001-05-28 22:30:08 +0000549C API
550
551- Removed the unused last_is_sticky argument from the internal
552 _PyTuple_Resize(). If this affects you, you were cheating.
553
554
Guido van Rossum55a78992001-07-17 17:22:32 +0000555======================================================================
556
557
Guido van Rossumffe13be2001-04-16 18:46:45 +0000558What's New in Python 2.1 (final)?
559=================================
560
561We only changed a few things since the last release candidate, all in
562Python library code:
563
564- A bug in the locale module was fixed that affected locales which
565 define no grouping for numeric formatting.
566
567- A few bugs in the weakref module's implementations of weak
568 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
569 and the test suite was updated to check for these bugs.
570
571- An old bug in the os.path.walk() function (introduced in Python
572 2.0!) was fixed: a non-existent file would cause an exception
573 instead of being ignored.
574
575- Fixed a few bugs in the new symtable module found by Neil Norwitz's
576 PyChecker.
577
578
Guido van Rossum5b08f132001-04-16 02:05:23 +0000579What's New in Python 2.1c2?
580===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000581
Guido van Rossum5b08f132001-04-16 02:05:23 +0000582A flurry of small changes, and one showstopper fixed in the nick of
583time made it necessary to release another release candidate. The list
584here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000585
Guido van Rossum5b08f132001-04-16 02:05:23 +0000586Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000587
Guido van Rossum5b08f132001-04-16 02:05:23 +0000588- Tim discovered a nasty bug in the dictionary code, caused by
589 PyDict_Next() calling dict_resize(), and the GC code's use of
590 PyDict_Next() violating an assumption in dict_items(). This was
591 fixed with considerable amounts of band-aid, but the net effect is a
592 saner and more robust implementation.
593
594- Made a bunch of symbols static that were accidentally global.
595
596Build and Ports
597
598- The setup.py script didn't check for a new enough version of zlib
599 (1.1.3 is needed). Now it does.
600
601- Changed "make clean" target to also remove shared libraries.
602
603- Added a more general warning about the SGI Irix optimizer to README.
604
605Library
606
607- Fix a bug in urllib.basejoin("http://host", "../file.html") which
608 omitted the slash between host and file.html.
609
610- The mailbox module's _Mailbox class contained a completely broken
611 and undocumented seek() method. Ripped it out.
612
613- Fixed a bunch of typos in various library modules (urllib2, smtpd,
614 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
615
616- Fixed a few last-minute bugs in unittest.
617
618Extensions
619
620- Reverted the patch to the OpenSSL code in socketmodule.c to support
621 RAND_status() and the EGD, and the subsequent patch that tried to
622 fix it for pre-0.9.5 versions; the problem with the patch is that on
623 some systems it issues a warning whenever socket is imported, and
624 that's unacceptable.
625
626Tests
627
628- Fixed the pickle tests to work with "import test.test_pickle".
629
630- Tweaked test_locale.py to actually run the test Windows.
631
632- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
633 not "wb" (which is not a valid mode at all).
634
635- Fix pstats browser crashes. Import readline if it exists to make
636 the user interface nicer.
637
638- Add "import thread" to the top of test modules that import the
639 threading module (test_asynchat and test_threadedtempfile). This
640 prevents test failures caused by a broken threading module resulting
641 from a previously caught failed import.
642
643- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
644 needed on some platforms (e.g. Solaris 8) when the tests are run
645 twice in succession.
646
647- Skip rather than fail test_sunaudiodev if no audio device is found.
648
649
650What's New in Python 2.1c1?
651===========================
652
653This list was significantly updated when 2.1c2 was released; the 2.1c1
654release didn't mention most changes that were actually part of 2.1c1:
655
656Legal
657
658- Copyright was assigned to the Python Software Foundation (PSF) and a
659 PSF license (very similar to the CNRI license) was added.
660
661- The CNRI copyright notice was updated to include 2001.
662
663Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000664
Guido van Rossumc9932722001-04-12 02:31:27 +0000665- After a public outcry, assignment to __debug__ is no longer illegal;
666 instead, a warning is issued. It will become illegal in 2.2.
667
Guido van Rossum5b08f132001-04-16 02:05:23 +0000668- Fixed a core dump with "%#x" % 0, and changed the semantics so that
669 "%#x" now always prepends "0x", even if the value is zero.
670
671- Fixed some nits in the bytecode compiler.
672
673- Fixed core dumps when calling certain kinds of non-functions.
674
675- Fixed various core dumps caused by reference count bugs.
676
677Build and Ports
678
679- Use INSTALL_SCRIPT to install script files.
680
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000681- New port: SCO Unixware 7, by Billy G. Allie.
682
Guido van Rossum5b08f132001-04-16 02:05:23 +0000683- Updated RISCOS port.
684
685- Updated BeOS port and notes.
686
687- Various other porting problems resolved.
688
689Library
690
691- The TERMIOS and SOCKET modules are now truly obsolete and
692 unnecessary. Their symbols are incorporated in the termios and
693 socket modules.
694
695- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
696 better tests for pickling.
697
698- threading: make Condition.wait() robust against KeyboardInterrupt.
699
700- zipfile: add support to zipfile to support opening an archive
701 represented by an open file rather than a file name. Fix bug where
702 the archive was not properly closed. Fixed a bug in this bugfix
703 where flush() was called for a read-only file.
704
705- imputil: added an uninstall() method to the ImportManager.
706
707- Canvas: fixed bugs in lower() and tkraise() methods.
708
709- SocketServer: API change (added overridable close_request() method)
710 so that the TCP server can explicitly close the request.
711
712- pstats: Eric Raymond added a simple interactive statistics browser,
713 invoked when the module is run as a script.
714
715- locale: fixed a problem in format().
716
717- webbrowser: made it work when the BROWSER environment variable has a
718 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
719 KDE 2. Fixed some other nits.
720
721- unittest: changes to allow using a different exception than
722 AssertionError, and added a few more function aliases. Some other
723 small changes.
724
725- urllib, urllib2: fixed redirect problems and a coupleof other nits.
726
727- asynchat: fixed a critical bug in asynchat that slipped through the
728 2.1b2 release. Fixed another rare bug.
729
730- Fix some unqualified except: clauses (always a bad code example).
731
732XML
733
734- pyexpat: new API get_version_string().
735
736- Fixed some minidom bugs.
737
738Extensions
739
740- Fixed a core dump in _weakref. Removed the weakref.mapping()
741 function (it adds nothing to the API).
742
743- Rationalized the use of header files in the readline module, to make
744 it compile (albeit with some warnings) with the very recent readline
745 4.2, without breaking for earlier versions.
746
747- Hopefully fixed a buffering problem in linuxaudiodev.
748
749- Attempted a fix to make the OpenSSL support in the socket module
750 work again with pre-0.9.5 versions of OpenSSL.
751
752Tests
753
754- Added a test case for asynchat and asyncore.
755
756- Removed coupling between tests where one test failing could break
757 another.
758
759Tools
760
761- Ping added an interactive help browser to pydoc, fixed some nits
762 in the rest of the pydoc code, and added some features to his
763 inspect module.
764
765- An updated python-mode.el version 4.1 which integrates Ken
766 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
767 much nicer in XEmacs and Emacs. When stepping through your program
768 with pdb, in either the shell window or the *Python* window, the
769 source file and line will be tracked by an arrow. Very cool!
770
771- IDLE: syntax warnings in interactive mode are changed into errors.
772
773- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000774 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000775
776- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000777
Barry Warsaw11e89c72001-04-11 20:37:57 +0000778
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000779What's New in Python 2.1 beta 2?
780================================
781
Guido van Rossum053ae352001-03-22 14:17:21 +0000782(Unlisted are many fixed bugs, more documentation, etc.)
783
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000784Core language, builtins, and interpreter
785
Guido van Rossum053ae352001-03-22 14:17:21 +0000786- The nested scopes work (enabled by "from __future__ import
787 nested_scopes") is completed; in particular, the future now extends
788 into code executed through exec, eval() and execfile(), and into the
789 interactive interpreter.
790
791- When calling a base class method (e.g. BaseClass.__init__(self)),
792 this is now allowed even if self is not strictly spoken a class
793 instance (e.g. when using metaclasses or the Don Beaudry hook).
794
795- Slice objects are now comparable but not hashable; this prevents
796 dict[:] from being accepted but meaningless.
797
798- Complex division is now calculated using less braindead algorithms.
799 This doesn't change semantics except it's more likely to give useful
800 results in extreme cases. Complex repr() now uses full precision
801 like float repr().
802
803- sgmllib.py now calls handle_decl() for simple <!...> declarations.
804
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000805- It is illegal to assign to the name __debug__, which is set when the
806 interpreter starts. It is effectively a compile-time constant.
807
808- A warning will be issued if a global statement for a variable
809 follows a use or assignment of that variable.
810
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000811Standard library
812
Guido van Rossum053ae352001-03-22 14:17:21 +0000813- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
814 inspired by JUnit), is now part of the standard library. You now
815 have a choice of two testing frameworks: unittest requires you to
816 write testcases as separate code, doctest gathers them from
817 docstrings. Both approaches have their advantages and
818 disadvantages.
819
820- A new module Tix was added, which wraps the Tix extension library
821 for Tk. With that module, it is not necessary to statically link
822 Tix with _tkinter, since Tix will be loaded with Tcl's "package
823 require" command. See Demo/tix/.
824
825- tzparse.py is now obsolete.
826
827- In gzip.py, the seek() and tell() methods are removed -- they were
828 non-functional anyway, and it's better if callers can test for their
829 existence with hasattr().
830
831Python/C API
832
833- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
834 that's already in the dictionary during a PyDict_Next() iteration.
835 This used to fail occasionally when a dictionary resize operation
836 could be triggered that would rehash all the keys. All other
837 modifications to the dictionary are still off-limits during a
838 PyDict_Next() iteration!
839
840- New extended APIs related to passing compiler variables around.
841
842- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
843 implement isinstance() and issubclass().
844
845- Py_BuildValue() now has a "D" conversion to create a Python complex
846 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000847
Fred Drake4e262a92001-03-22 18:26:47 +0000848- Extensions types which support weak references must now set the
849 field allocated for the weak reference machinery to NULL themselves;
850 this is done to avoid the cost of checking each object for having a
851 weakly referencable type in PyObject_INIT(), since most types are
852 not weakly referencable.
853
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000854- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
855 free variables and cell variables to and from the frame's f_locals.
856
857- Variants of several functions defined in pythonrun.h have been added
858 to support the nested_scopes future statement. The variants all end
859 in Flags and take an extra argument, a PyCompilerFlags *; examples:
860 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
861 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000862 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000863
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000864Distutils
865
866- the sdist command now writes a PKG-INFO file, as described in PEP 241,
867 into the release tree.
868
Tim Peters0e57abf2001-05-02 07:39:38 +0000869- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000870 (an uninstaller, more customization of the installer's display)
871
872- from Jack Jansen: added Mac-specific code to generate a dialog for
873 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000874 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000875 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000876
877- added 'platforms' and 'keywords' to the set of metadata that can be
878 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000879
880- applied patches from Jason Tishler to make the compiler class work with
881 Cygwin.
882
883
Tim Peters2fe289a2001-03-01 22:19:38 +0000884What's New in Python 2.1 beta 1?
885================================
Tim Petersd66595f2001-02-04 03:09:53 +0000886
887Core language, builtins, and interpreter
888
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000889- Following an outcry from the community about the amount of code
890 broken by the nested scopes feature introduced in 2.1a2, we decided
891 to make this feature optional, and to wait until Python 2.2 (or at
892 least 6 months) to make it standard. The option can be enabled on a
893 per-module basis by adding "from __future__ import nested_scopes" at
894 the beginning of a module (before any other statements, but after
895 comments and an optional docstring). See PEP 236 (Back to the
896 __future__) for a description of the __future__ statement. PEP 227
897 (Statically Nested Scopes) has been updated to reflect this change,
898 and to clarify the semantics in a number of endcases.
899
900- The nested scopes code, when enabled, has been hardened, and most
901 bugs and memory leaks in it have been fixed.
902
903- Compile-time warnings are now generated for a number of conditions
904 that will break or change in meaning when nested scopes are enabled:
905
906 - Using "from...import *" or "exec" without in-clause in a function
907 scope that also defines a lambda or nested function with one or
908 more free (non-local) variables. The presence of the import* or
909 bare exec makes it impossible for the compiler to determine the
910 exact set of local variables in the outer scope, which makes it
911 impossible to determine the bindings for free variables in the
912 inner scope. To avoid the warning about import *, change it into
913 an import of explicitly name object, or move the import* statement
914 to the global scope; to avoid the warning about bare exec, use
915 exec...in... (a good idea anyway -- there's a possibility that
916 bare exec will be deprecated in the future).
917
918 - Use of a global variable in a nested scope with the same name as a
919 local variable in a surrounding scope. This will change in
920 meaning with nested scopes: the name in the inner scope will
921 reference the variable in the outer scope rather than the global
922 of the same name. To avoid the warning, either rename the outer
923 variable, or use a global statement in the inner function.
924
Neil Schemenauera35c6882001-02-27 04:45:05 +0000925- An optional object allocator has been included. This allocator is
926 optimized for Python objects and should be faster and use less memory
927 than the standard system allocator. It is not enabled by default
928 because of possible thread safety problems. The allocator is only
929 protected by the Python interpreter lock and it is possible that some
930 extension modules require a thread safe allocator. The object
931 allocator can be enabled by providing the "--with-pymalloc" option to
932 configure.
933
Tim Petersd66595f2001-02-04 03:09:53 +0000934Standard library
935
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000936- pyexpat now detects the expat version if expat.h defines it. A
937 number of additional handlers are provided, which are only available
938 since expat 1.95. In addition, the methods SetParamEntityParsing and
939 GetInputContext of Parser objects are available with 1.95.x
940 only. Parser objects now provide the ordered_attributes and
941 specified_attributes attributes. A new module expat.model was added,
942 which offers a number of additional constants if 1.95.x is used.
943
944- xml.dom offers the new functions registerDOMImplementation and
945 getDOMImplementation.
946
947- xml.dom.minidom offers a toprettyxml method. A number of DOM
948 conformance issues have been resolved. In particular, Element now
949 has an hasAttributes method, and the handling of namespaces was
950 improved.
951
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000952- Ka-Ping Yee contributed two new modules: inspect.py, a module for
953 getting information about live Python code, and pydoc.py, a module
954 for interactively converting docstrings to HTML or text.
955 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000956 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000957 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
958 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000959
Tim Peters1eff7962001-03-01 02:31:33 +0000960- New library module difflib.py, primarily packaging the SequenceMatcher
961 class at the heart of the popular ndiff.py file-comparison tool.
962
963- doctest.py (a framework for verifying Python code examples in docstrings)
964 is now part of the std library.
965
Tim Petersd66595f2001-02-04 03:09:53 +0000966Windows changes
967
Guido van Rossume3955a82001-03-02 14:05:59 +0000968- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
969 small GUI that lets you browse the module docstrings using your
970 default web browser.
971
Tim Peters1eff7962001-03-01 02:31:33 +0000972- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
973 Platforms) is implemented. See
974
975 http://python.sourceforge.net/peps/pep-0235.html
976
977 for full details, especially the "Current Lower-Left Semantics" section.
978 The new Windows import rules are simpler than before:
979
980 A. If the PYTHONCASEOK environment variable exists, same as
981 before: silently accept the first case-insensitive match of any
982 kind; raise ImportError if none found.
983
984 B. Else search sys.path for the first case-sensitive match; raise
985 ImportError if none found.
986
987 The same rules have been implented on other platforms with case-
988 insensitive but case-preserving filesystems too (including Cygwin, and
989 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000990
Tim Peters25a9ce32001-02-19 07:06:36 +0000991- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
992 what it's supposed to do (and does do under NT and 2000) via direct
993 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000994 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000995 all Win9x systems before.
996
Tim Peters1eff7962001-03-01 02:31:33 +0000997- Build: Subproject _test (effectively) renamed to _testcapi.
998
Tim Peters2fe289a2001-03-01 22:19:38 +0000999New platforms
1000
1001- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1002 Thanks to Steven Majewski!
1003
1004- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1005 Tishler!
1006
Guido van Rossum9089b272001-03-02 06:49:50 +00001007- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1008 Schwertberger! See RISCOS/README for more information -- it seems
1009 that because of the bizarre filename conventions on RISCOS, no port
1010 to that platform is easy. Note that the new variable os.endsep is
1011 silently supported in order to make life easier on this platform,
1012 but we don't advertise it because it's not worth for most folks to
1013 care about RISCOS portability.
1014
Tim Peters25a9ce32001-02-19 07:06:36 +00001015
Tim Petersd7b5e882001-01-25 03:36:26 +00001016What's New in Python 2.1 alpha 2?
1017=================================
Tim Peters40ead762001-01-27 05:35:26 +00001018
Tim Petersd7b5e882001-01-25 03:36:26 +00001019Core language, builtins, and interpreter
1020
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001021- Scopes nest. If a name is used in a function or class, but is not
1022 local, the definition in the nearest enclosing function scope will
1023 be used. One consequence of this change is that lambda statements
1024 could reference variables in the namespaces where the lambda is
1025 defined. In some unusual cases, this change will break code.
1026
1027 In all previous version of Python, names were resolved in exactly
1028 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001029 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001030 function A is defined within a function B, the names bound in B are
1031 not visible in A. The new rules make names bound in B visible in A,
1032 unless A contains a name binding that hides the binding in B.
1033
1034 Section 4.1 of the reference manual describes the new scoping rules
1035 in detail. The test script in Lib/test/test_scope.py demonstrates
1036 some of the effects of the change.
1037
1038 The new rules will cause existing code to break if it defines nested
1039 functions where an outer function has local variables with the same
1040 name as globals or builtins used by the inner function. Example:
1041
1042 def munge(str):
1043 def helper(x):
1044 return str(x)
1045 if type(str) != type(''):
1046 str = helper(str)
1047 return str.strip()
1048
1049 Under the old rules, the name str in helper() is bound to the
1050 builtin function str(). Under the new rules, it will be bound to
1051 the argument named str and an error will occur when helper() is
1052 called.
1053
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001054- The compiler will report a SyntaxError if "from ... import *" occurs
1055 in a function or class scope. The language reference has documented
1056 that this case is illegal, but the compiler never checked for it.
1057 The recent introduction of nested scope makes the meaning of this
1058 form of name binding ambiguous. In a future release, the compiler
1059 may allow this form when there is no possibility of ambiguity.
1060
Tim Peters40ead762001-01-27 05:35:26 +00001061- repr(string) is easier to read, now using hex escapes instead of octal,
1062 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1063
1064 >>> "\texample \r\n" + chr(0) + chr(255)
1065 '\texample \r\n\x00\xff' # in 2.1
1066 '\011example \015\012\000\377' # in 2.0
1067
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001068- Functions are now compared and hashed by identity, not by value, since
1069 the func_code attribute is writable.
1070
Fred Drakefb9d7122001-02-01 20:00:40 +00001071- Weak references (PEP 205) have been added. This involves a few
1072 changes in the core, an extension module (_weakref), and a Python
1073 module (weakref). The weakref module is the public interface. It
1074 includes support for "explicit" weak references, proxy objects, and
1075 mappings with weakly held values.
1076
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001077- A 'continue' statement can now appear in a try block within the body
1078 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001079 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001080
Tim Petersd7b5e882001-01-25 03:36:26 +00001081Standard library
1082
Barry Warsaw30dbd142001-01-31 22:14:01 +00001083- mailbox.py now has a new class, PortableUnixMailbox which is
1084 identical to UnixMailbox but uses a more portable scheme for
1085 determining From_ separators. Also, the constructors for all the
1086 classes in this module have a new optional `factory' argument, which
1087 is a callable used when new message classes must be instantiated by
1088 the next() method.
1089
Tim Petersd7b5e882001-01-25 03:36:26 +00001090- random.py is now self-contained, and offers all the functionality of
1091 the now-deprecated whrandom.py. See the docs for details. random.py
1092 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001093 and restoring the internal state of the generator; and jumpahead(n),
1094 for quickly forcing the internal state to be the same as if n calls to
1095 random() had been made. The latter is particularly useful for multi-
1096 threaded programs, creating one instance of the random.Random() class for
1097 each thread, then using .jumpahead() to force each instance to use a
1098 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001099
Tim Peters0de88fc2001-02-01 04:59:18 +00001100- random.py's seed() function is new. For bit-for-bit compatibility with
1101 prior releases, use the whseed function instead. The new seed function
1102 addresses two problems: (1) The old function couldn't produce more than
1103 about 2**24 distinct internal states; the new one about 2**45 (the best
1104 that can be done in the Wichmann-Hill generator). (2) The old function
1105 sometimes produced identical internal states when passed distinct
1106 integers, and there was no simple way to predict when that would happen;
1107 the new one guarantees to produce distinct internal states for all
1108 arguments in [0, 27814431486576L).
1109
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001110- The socket module now supports raw packets on Linux. The socket
1111 family is AF_PACKET.
1112
Tim Peters9ea17ac2001-02-02 05:57:15 +00001113- test_capi.py is a start at running tests of the Python C API. The tests
1114 are implemented by the new Modules/_testmodule.c.
1115
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001116- A new extension module, _symtable, provides provisional access to the
1117 internal symbol table used by the Python compiler. A higher-level
1118 interface will be added on top of _symtable in a future release.
1119
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001120- Removed the obsolete soundex module.
1121
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001122- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1123 the isSameNode method; NamedNodeMap the get method.
1124
1125- xml.sax.expatreader supports the lexical handler property; it
1126 generates comment, startCDATA, and endCDATA events.
1127
Tim Petersee826f82001-01-31 19:39:44 +00001128Windows changes
1129
1130- Build procedure: the zlib project is built in a different way that
1131 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001132 the zlib binary used. See PCbuild\readme.txt for details. Your old
1133 zlib-related directories can be deleted; you'll need to download fresh
1134 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001135
Tim Peters9ea17ac2001-02-02 05:57:15 +00001136- Build: New subproject _test for the benefit of test_capi.py (see above).
1137
Tim Petersb16c56f2001-02-02 21:24:51 +00001138- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1139 interface to some Python compiler internals).
1140
1141- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001142 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001143
Tim Petersa3a3a032000-11-30 05:22:44 +00001144What's New in Python 2.1 alpha 1?
1145=================================
1146
1147Core language, builtins, and interpreter
1148
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001149- There is a new Unicode companion to the PyObject_Str() API
1150 called PyObject_Unicode(). It behaves in the same way as the
1151 former, but assures that the returned value is an Unicode object
1152 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001153
Guido van Rossumf98eda02001-01-17 15:54:45 +00001154- The comparison operators support "rich comparison overloading" (PEP
1155 207). C extension types can provide a rich comparison function in
1156 the new tp_richcompare slot in the type object. The cmp() function
1157 and the C function PyObject_Compare() first try the new rich
1158 comparison operators before trying the old 3-way comparison. There
1159 is also a new C API PyObject_RichCompare() (which also falls back on
1160 the old 3-way comparison, but does not constrain the outcome of the
1161 rich comparison to a Boolean result).
1162
1163 The rich comparison function takes two objects (at least one of
1164 which is guaranteed to have the type that provided the function) and
1165 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1166 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1167 object, which may be NotImplemented (in which case the tp_compare
1168 slot function is used as a fallback, if defined).
1169
1170 Classes can overload individual comparison operators by defining one
1171 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001172 __ge__. There are no explicit "reflected argument" versions of
1173 these; instead, __lt__ and __gt__ are each other's reflection,
1174 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1175 reflection (similar at the C level). No other implications are
1176 made; in particular, Python does not assume that == is the Boolean
1177 inverse of !=, or that < is the Boolean inverse of >=. This makes
1178 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001179
1180 Classes or types that want to implement (in)equality tests but not
1181 the ordering operators (i.e. unordered types) should implement ==
1182 and !=, and raise an error for the ordering operators.
1183
Guido van Rossuma88479f2001-01-18 14:28:08 +00001184 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001185 Boolean; e.g. a matrix type might want to return a matrix of bits
1186 for A < B, giving elementwise comparisons. Such types should ensure
1187 that any interpretation of their value in a Boolean context raises
1188 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1189 at the C level) to always raise an exception.
1190
Guido van Rossuma88479f2001-01-18 14:28:08 +00001191- Complex numbers use rich comparisons to define == and != but raise
1192 an exception for <, <=, > and >=. Unfortunately, this also means
1193 that cmp() of two complex numbers raises an exception when the two
1194 numbers differ. Since it is not mathematically meaningful to compare
1195 complex numbers except for equality, I hope that this doesn't break
1196 too much code.
1197
Tim Peters3389f192001-02-18 08:48:49 +00001198- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001199 not defined by the language, other than that it's arbitrary but
1200 consistent (see the Reference Manual). An implementation detail changed
1201 in 2.1a1 such that None now compares less than any other object. Code
1202 relying on this new behavior (like code that relied on the previous
1203 behavior) does so at its own risk.
1204
Barry Warsaw573b5412001-01-15 20:43:18 +00001205- Functions and methods now support getting and setting arbitrarily
1206 named attributes (PEP 232). Functions have a new __dict__
1207 (a.k.a. func_dict) which hold the function attributes. Methods get
1208 and set attributes on their underlying im_func. It is a TypeError
1209 to set an attribute on a bound method.
1210
Guido van Rossum051e3352001-01-15 19:11:10 +00001211- The xrange() object implementation has been improved so that
1212 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1213 limitation that in this case len(xrange(sys.maxint)) can't be
1214 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1215 work fine as long as the index i doesn't actually reach 2**31.
1216 (Python uses regular ints for sequence and string indices; fixing
1217 that is much more work.)
1218
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001219- Two changes to from...import:
1220
Guido van Rossumba381232001-02-03 15:06:40 +00001221 1) "from M import X" now works even if (after loading module M)
1222 sys.modules['M'] is not a real module; it's basically a getattr()
1223 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001224
1225 2) "from M import *" now looks for M.__all__ to decide which names to
1226 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1227 filters out names starting with '_' as before. Whether or not
1228 __all__ exists, there's no restriction on the type of M.
1229
Guido van Rossumf61f1662001-01-10 20:13:55 +00001230- File objects have a new method, xreadlines(). This is the fastest
1231 way to iterate over all lines in a file:
1232
1233 for line in file.xreadlines():
1234 ...do something to line...
1235
1236 See the xreadlines module (mentioned below) for how to do this for
1237 other file-like objects.
1238
1239- Even if you don't use file.xreadlines(), you may expect a speedup on
1240 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001241 quite a bit in platform-specific ways: on systems (like Linux) that
1242 support flockfile(), getc_unlocked(), and funlockfile(), those are
1243 used by default. On systems (like Windows) without getc_unlocked(),
1244 a complicated (but still thread-safe) method using fgets() is used by
1245 default.
1246
Tim Petersd52269b2001-01-25 06:23:18 +00001247 You can force use of the fgets() method by #define'ing
1248 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001249 getc_unlocked()).
1250
Tim Petersd52269b2001-01-25 06:23:18 +00001251 You can force fgets() not to be used by #define'ing
1252 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001253 test_bufio.py fails -- and let us know if it does!).
1254
1255- In addition, the fileinput module, while still slower than the other
1256 methods on most platforms, has been sped up too, by using
1257 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001258
1259- Support for run-time warnings has been added, including a new
1260 command line option (-W) to specify the disposition of warnings.
1261 See the description of the warnings module below.
1262
1263- Extensive changes have been made to the coercion code. This mostly
1264 affects extension modules (which can now implement mixed-type
1265 numerical operators without having to use coercion), but
1266 occasionally, in boundary cases the coercion semantics have changed
1267 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001268 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001269 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001270 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001271
Guido van Rossumf98eda02001-01-17 15:54:45 +00001272- In connection with the coercion changes, a new built-in singleton
1273 object, NotImplemented is defined. This can be returned for
1274 operations that wish to indicate they are not implemented for a
1275 particular combination of arguments. From C, this is
1276 Py_NotImplemented.
1277
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001278- The interpreter accepts now bytecode files on the command line even
1279 if they do not have a .pyc or .pyo extension. On Linux, after executing
1280
Martin v. Löwise214baa2001-02-04 22:37:56 +00001281import imp,sys,string
1282magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1283reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1284open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001285
1286 any byte code file can be used as an executable (i.e. as an argument
1287 to execve(2)).
1288
Tim Peters9940b802000-12-01 07:59:35 +00001289- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001290 character. In 1.6 and earlier, they never produced a sign,
1291 and raised an error if the value of the long was too large
1292 to fit in a Python int. In 2.0, they produced a sign if and
1293 only if too large to fit in an int. This was inconsistent
1294 across platforms (because the size of an int varies across
1295 platforms), and inconsistent with hex() and oct(). Example:
1296
1297 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001298 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001299 'ffffffbe' # in 2.0 and before, on 32-bit machines
1300 >>> hex(-0x42L)
1301 '-0x42L' # in all versions of Python
1302
Tim Peters9940b802000-12-01 07:59:35 +00001303 The behavior of %d formats for negative Python longs remains
1304 the same as in 2.0 (although in 1.6 and before, they raised
1305 an error if the long didn't fit in a Python int).
1306
1307 %u formats don't make sense for Python longs, but are allowed
1308 and treated the same as %d in 2.1. In 2.0, a negative long
1309 formatted via %u produced a sign if and only if too large to
1310 fit in an int. In 1.6 and earlier, a negative long formatted
1311 via %u raised an error if it was too big to fit in an int.
1312
Guido van Rossum3661d392000-12-12 22:10:31 +00001313- Dictionary objects have an odd new method, popitem(). This removes
1314 an arbitrary item from the dictionary and returns it (in the form of
1315 a (key, value) pair). This can be useful for algorithms that use a
1316 dictionary as a bag of "to do" items and repeatedly need to pick one
1317 item. Such algorithms normally end up running in quadratic time;
1318 using popitem() they can usually be made to run in linear time.
1319
Tim Peters36cdad12000-12-29 02:06:45 +00001320Standard library
1321
Thomas Woutersfe385252001-01-19 23:16:56 +00001322- In the time module, the time argument to the functions strftime,
1323 localtime, gmtime, asctime and ctime is now optional, defaulting to
1324 the current time (in the local timezone).
1325
Guido van Rossumda91f222001-01-15 16:36:08 +00001326- The ftplib module now defaults to passive mode, which is deemed a
1327 more useful default given that clients are often inside firewalls
1328 these days. Note that this could break if ftplib is used to connect
1329 to a *server* that is inside a firewall, from outside; this is
1330 expected to be a very rare situation. To fix that, you can call
1331 ftp.set_pasv(0).
1332
Martin v. Löwis10a27872001-01-13 09:54:41 +00001333- The module site now treats .pth files not only for path configuration,
1334 but also supports extensions to the initialization code: Lines starting
1335 with import are executed.
1336
Guido van Rossumf61f1662001-01-10 20:13:55 +00001337- There's a new module, warnings, which implements a mechanism for
1338 issuing and filtering warnings. There are some new built-in
1339 exceptions that serve as warning categories, and a new command line
1340 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1341 turns warnings into errors). warnings.warn(message[, category])
1342 issues a warning message; this can also be called from C as
1343 PyErr_Warn(category, message).
1344
1345- A new module xreadlines was added. This exports a single factory
1346 function, xreadlines(). The intention is that this code is the
1347 absolutely fastest way to iterate over all lines in an open
1348 file(-like) object:
1349
1350 import xreadlines
1351 for line in xreadlines.xreadlines(file):
1352 ...do something to line...
1353
1354 This is equivalent to the previous the speed record holder using
1355 file.readlines(sizehint). Note that if file is a real file object
1356 (as opposed to a file-like object), this is equivalent:
1357
1358 for line in file.xreadlines():
1359 ...do something to line...
1360
Tim Peters36cdad12000-12-29 02:06:45 +00001361- The bisect module has new functions bisect_left, insort_left,
1362 bisect_right and insort_right. The old names bisect and insort
1363 are now aliases for bisect_right and insort_right. XXX_right
1364 and XXX_left methods differ in what happens when the new element
1365 compares equal to one or more elements already in the list: the
1366 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001367 right. Code that doesn't care where equal elements end up should
1368 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001369
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001370- The new curses.panel module wraps the panel library that forms part
1371 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1372
Guido van Rossumf61f1662001-01-10 20:13:55 +00001373- The SocketServer module now sets the allow_reuse_address flag by
1374 default in the TCPServer class.
1375
1376- A new function, sys._getframe(), returns the stack frame pointer of
1377 the caller. This is intended only as a building block for
1378 higher-level mechanisms such as string interpolation.
1379
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001380- The pyexpat module supports a number of new handlers, which are
1381 available only in expat 1.2. If invocation of a callback fails, it
1382 will report an additional frame in the traceback. Parser objects
1383 participate now in garbage collection. If expat reports an unknown
1384 encoding, pyexpat will try to use a Python codec; that works only
1385 for single-byte charsets. The parser type objects is exposed as
1386 XMLParserObject.
1387
1388- xml.dom now offers standard definitions for symbolic node type and
1389 exception code constants, and a hierarchy of DOM exceptions. minidom
1390 was adjusted to use them.
1391
1392- The conformance of xml.dom.minidom to the DOM specification was
1393 improved. It detects a number of additional error cases; the
1394 previous/next relationship works even when the tree is modified;
1395 Node supports the normalize() method; NamedNodeMap, DocumentType and
1396 DOMImplementation classes were added; Element supports the
1397 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1398 method.
1399
Guido van Rossumf61f1662001-01-10 20:13:55 +00001400Build issues
1401
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001402- For Unix (and Unix-compatible) builds, configuration and building of
1403 extension modules is now greatly automated. Rather than having to
1404 edit the Modules/Setup file to indicate which modules should be
1405 built and where their include files and libraries are, a
1406 distutils-based setup.py script now takes care of building most
1407 extension modules. All extension modules built this way are built
1408 as shared libraries. Only a few modules that must be linked
1409 statically are still listed in the Setup file; you won't need to
1410 edit their configuration.
1411
1412- Python should now build out of the box on Cygwin. If it doesn't,
1413 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001414
1415- Python now always uses its own (renamed) implementation of getopt()
1416 -- there's too much variation among C library getopt()
1417 implementations.
1418
1419- C++ compilers are better supported; the CXX macro is always set to a
1420 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001421
Tim Petersd92dfe02000-12-12 01:18:41 +00001422Windows changes
1423
1424- select module: By default under Windows, a select() call
1425 can specify no more than 64 sockets. Python now boosts
1426 this Microsoft default to 512. If you need even more than
1427 that, see the MS docs (you'll need to #define FD_SETSIZE
1428 and recompile Python from source).
1429
Guido van Rossumf61f1662001-01-10 20:13:55 +00001430- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1431 subdirectory is no more!
1432
Tim Petersa3a3a032000-11-30 05:22:44 +00001433
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001434What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001435=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001436
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001437Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001438changes are in the file HISTORY. If you are making the jump directly
1439from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1440HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001441
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001442Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1443the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1444http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001445
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001446--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001447
1448======================================================================
1449
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001450What's new in 2.0 (since release candidate 1)?
1451==============================================
1452
1453Standard library
1454
1455- The copy_reg module was modified to clarify its intended use: to
1456 register pickle support for extension types, not for classes.
1457 pickle() will raise a TypeError if it is passed a class.
1458
1459- Fixed a bug in gettext's "normalize and expand" code that prevented
1460 it from finding an existing .mo file.
1461
1462- Restored support for HTTP/0.9 servers in httplib.
1463
Tim Peters989b7b92000-10-16 20:24:53 +00001464- The math module was changed to stop raising OverflowError in case of
1465 underflow, and return 0 instead in underflow cases. Whether Python
1466 used to raise OverflowError in case of underflow was platform-
1467 dependent (it did when the platform math library set errno to ERANGE
1468 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001469
1470- Fixed a bug in StringIO that occurred when the file position was not
1471 at the end of the file and write() was called with enough data to
1472 extend past the end of the file.
1473
1474- Fixed a bug that caused Tkinter error messages to get lost on
1475 Windows. The bug was fixed by replacing direct use of
1476 interp->result with Tcl_GetStringResult(interp).
1477
1478- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1479 redirect response.
1480
1481- Several changes were made to distutils: Some debugging code was
1482 removed from util. Fixed the installer used when an external zip
1483 program (like WinZip) is not found; the source code for this
1484 installer is in Misc/distutils. check_lib() was modified to behave
1485 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1486 test for whether installed modules are on sys.path was changed to
1487 use both normcase() and normpath().
1488
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001489- Several minor bugs were fixed in the xml package (the minidom,
1490 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001491
1492- The regression test driver (regrtest.py) behavior when invoked with
1493 -l changed: It now reports a count of objects that are recognized as
1494 garbage but not freed by the garbage collector.
1495
Tim Peters989b7b92000-10-16 20:24:53 +00001496- The regression test for the math module was changed to test
1497 exceptional behavior when the test is run in verbose mode. Python
1498 cannot yet guarantee consistent exception behavior across platforms,
1499 so the exception part of test_math is run only in verbose mode, and
1500 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001501
1502Internals
1503
1504- PyOS_CheckStack() has been disabled on Win64, where it caused
1505 test_sre to fail.
1506
1507Build issues
1508
1509- Changed compiler flags, so that gcc is always invoked with -Wall and
1510 -Wstrict-prototypes. Users compiling Python with GCC should see
1511 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001512 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001513 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001514
Tim Petersa3a3a032000-11-30 05:22:44 +00001515- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001516
1517Tools and other miscellany
1518
1519- The compiler in Tools/compiler was updated to support the new
1520 language features introduced in 2.0: extended print statement, list
1521 comprehensions, and augmented assignments. The new compiler should
1522 also be backwards compatible with Python 1.5.2; the compiler will
1523 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001524 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001525
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001526What's new in 2.0 release candidate 1 (since beta 2)?
1527=====================================================
1528
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001529What is release candidate 1?
1530
1531We believe that release candidate 1 will fix all known bugs that we
1532intend to fix for the 2.0 final release. This release should be a bit
1533more stable than the previous betas. We would like to see even more
1534widespread testing before the final release, so we are producing this
1535release candidate. The final release will be exactly the same unless
1536any show-stopping (or brown bag) bugs are found by testers of the
1537release candidate.
1538
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001539All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001540to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001541
1542Core language, builtins, and interpreter
1543
1544- A bug that caused crashes when __coerce__ was used with augmented
1545 assignment, e.g. +=, was fixed.
1546
1547- Raise ZeroDivisionError when raising zero to a negative number,
1548 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1549 power operator and the result of math.pow(0.0, -2.0) will vary by
1550 platform. On Linux, it raises a ValueError.
1551
1552- A bug in Unicode string interpolation was fixed that occasionally
1553 caused errors with formats including "%%". For example, the
1554 following expression "%% %s" % u"abc" no longer raises a TypeError.
1555
1556- Compilation of deeply nested expressions raises MemoryError instead
1557 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1558
1559- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1560 rendering them useless. They are now written in binary mode again.
1561
1562Standard library
1563
1564- Keyword arguments are now accepted for most pattern and match object
1565 methods in SRE, the standard regular expression engine.
1566
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001567- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001568 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001569
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001570- Several bugs in the Unicode handling and error handling in _tkinter
1571 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001572
1573- Fix memory management errors in Merge() and Tkapp_Call() routines.
1574
1575- Several changes were made to cStringIO to make it compatible with
1576 the file-like object interface and with StringIO. If operations are
1577 performed on a closed object, an exception is raised. The truncate
1578 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001579 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001580
1581- There were many changes made to the linuxaudiodev module and its
1582 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001583 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001584
1585 Note that this module is named poorly, because it should work
1586 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001587 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001588
1589 The module now raises exceptions when errors occur instead of
1590 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1591 audio) and defines a getptr() method that calls the
1592 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1593
1594- The library_version attribute, introduced in an earlier beta, was
1595 removed because it can not be supported with early versions of the C
1596 readline library, which provides no way to determine the version at
1597 compile-time.
1598
1599- The binascii module is now enabled on Win64.
1600
Tim Peters46446d62000-10-09 21:19:31 +00001601- tokenize.py no longer suffers "recursion depth" errors when parsing
1602 programs with very long string literals.
1603
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001604Internals
1605
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001606- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001607 which is called when the interpreter starts up to determine where
1608 the standard library is installed. These vulnerabilities affect all
1609 previous versions of Python and can be exploited by setting very
1610 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1611 setuid Python script, although use of the wrapper in
1612 Misc/setuid-prog.c will eliminate the vulnerability.
1613
1614- Fixed garbage collection bugs in instance creation that were
1615 triggered when errors occurred during initialization. The solution,
1616 applied in cPickle and in PyInstance_New(), is to call
1617 PyObject_GC_Init() after the initialization of the object's
1618 container attributes is complete.
1619
1620- pyexpat adds definitions of PyModule_AddStringConstant and
1621 PyModule_AddObject if the Python version is less than 2.0, which
1622 provides compatibility with PyXML on Python 1.5.2.
1623
1624- If the platform has a bogus definition for LONG_BIT (the number of
1625 bits in a long), an error will be reported at compile time.
1626
1627- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1628 collection crashes and possibly other, unreported crashes.
1629
1630- Fixed a memory leak in _PyUnicode_Fini().
1631
1632Build issues
1633
1634- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001635 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001636 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001637
1638- The mmap.PAGESIZE constant is now initialized using sysconf when
1639 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1640
1641- The md5 file should now compile on all platforms.
1642
1643- The select module now compiles on platforms that do not define
1644 POLLRDNORM and related constants.
1645
1646- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001647 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001648
Jeremy Hylton10921202000-10-09 18:34:12 +00001649- BeOS: A number of changes were made to the build and installation
1650 process. ar-fake now operates on a directory of object files.
1651 dl_export.h is gone, and its macros now appear on the mwcc command
1652 line during build on PPC BeOS.
1653
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001654- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001655 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001656
1657- Cygwin: Support for shared libraries, Tkinter, and sockets.
1658
1659- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1660
1661Tools and other miscellany
1662
1663- Removed debugging prints from main used with freeze.
1664
Tim Peters46446d62000-10-09 21:19:31 +00001665- IDLE auto-indent no longer crashes when it encounters Unicode
1666 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001667
1668What's new in 2.0 beta 2 (since beta 1)?
1669========================================
1670
1671Core language, builtins, and interpreter
1672
Tim Peters482c0212000-09-26 06:33:09 +00001673- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001674 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001675
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001676- Add -h and -V command line options to print the usage message and
1677 Python version number and exit immediately.
1678
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001679- eval() and exec accept Unicode objects as code parameters.
1680
1681- getattr() and setattr() now also accept Unicode objects for the
1682 attribute name, which are converted to strings using the default
1683 encoding before lookup.
1684
1685- Multiplication on string and Unicode now does proper bounds
1686 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1687 string is too long."
1688
1689- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001690 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001691
Jeremy Hylton1b618592000-09-26 05:32:36 +00001692
1693Standard library and extensions
1694
Guido van Rossum5b08f132001-04-16 02:05:23 +00001695- socket module: the OpenSSL code now adds support for RAND_status()
1696 and EGD (Entropy Gathering Device).
1697
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001698- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001699 argument checking; it still takes no arguments.
1700
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001701- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001702
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001703- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001704
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001705- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001706
1707- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001708 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001709
1710- copy: Copy Unicode objects atomically.
1711
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001712- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001713
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001714- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001715
Fred Drake67233bc2000-09-26 16:40:27 +00001716- dbm: Add get() and setdefault() methods to dbm object. Add constant
1717 `library' to module that names the library used. Added doc strings
1718 and method names to error messages. Uses configure to determine
1719 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1720 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001721
1722- distutils: Update to version 0.9.3.
1723
1724- dl: Add several dl.RTLD_ constants.
1725
1726- fpectl: Now supported on FreeBSD.
1727
1728- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1729 found by the collector will be saved in gc.garbage. This is useful
1730 for debugging a program that creates reference cycles.
1731
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001732- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001733 of HTTP class. Do not close socket on zero-length response. Do not
1734 crash when server sends invalid content-length header.
1735
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001736- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001737
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001738- marshal: When reading a short, sign-extend on platforms where shorts
1739 are bigger than 16 bits. When reading a long, repair the unportable
1740 sign extension that was being done for 64-bit machines. (It assumed
1741 that signed right shift sign-extends.)
1742
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001743- operator: Add contains(), invert(), __invert__() as aliases for
1744 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001745
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001746- os: Add support for popen2() and popen3() on all platforms where
1747 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001748
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001749- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001750 clicking on a file in Explorer (or passing the file name to the
1751 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001752
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001753- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001754 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001755
1756- pickle: Now raises ValueError when an invalid pickle that contains
1757 a non-string repr where a string repr was expected. This behavior
1758 matches cPickle.
1759
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001760- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001761
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001762- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001763
1764- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001765 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001766 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001767
1768- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001769 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001770
1771- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001772 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001773 few cycles during startup since the first call to
1774 setdefaultencoding() will initialize the codec registry and the
1775 encodings package.
1776
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001777- socket: Support for size hint in readlines() method of object returned
1778 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001779
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001780- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001781 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001782 is followed by whitespace.
1783
Tim Petersa3a3a032000-11-30 05:22:44 +00001784- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001785
1786- struct: Check ranges for bytes and shorts.
1787
1788- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001789 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001790
1791- Tkinter: Image objects are now guaranteed to have unique ids. Set
1792 event.delta to zero if Tk version doesn't support mousewheel.
1793 Removed some debugging prints.
1794
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001795- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001796
Fred Drake67233bc2000-09-26 16:40:27 +00001797- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001798 which works around a bug in Norton AntiVirus 2000 that leads directly
1799 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001800
1801- xml: New version detection code allows PyXML to override standard
1802 XML package if PyXML version is greater than 0.6.1.
1803
Fred Drake64bb3802000-09-26 16:21:35 +00001804- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1805 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1806 tree only for nodes which are sufficiently interesting to a specific
1807 application. Does not provide the HTML-specific extensions. Still
1808 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001809
Fred Drake64bb3802000-09-26 16:21:35 +00001810- xml.sax: SAX 2 support for Python, including all the handler
1811 interfaces needed to process XML 1.0 compliant XML. Some
1812 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001813
Fred Drake64bb3802000-09-26 16:21:35 +00001814- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1815 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001816
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001817
Jeremy Hylton1b618592000-09-26 05:32:36 +00001818C API
1819
1820- Add three new convenience functions for module initialization --
1821 PyModule_AddObject(), PyModule_AddIntConstant(), and
1822 PyModule_AddStringConstant().
1823
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001824- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001825 removed and add #error to Python.h if NULL isn't defined after
1826 #include of stdio.h.
1827
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001828- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001829 backwards compatibility (at the source level) with old extensions.
1830
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001831- A wrapper API was added for signal() and sigaction(). Instead of
1832 either function, always use PyOS_getsig() to get a signal handler
1833 and PyOS_setsig() to set one. A new convenience typedef
1834 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001835
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001836- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001837 internal data buffer and size of a string object -- or the default
1838 encoded version of a Unicode object.
1839
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001840- PyString_Size() and PyString_AsString() accept Unicode objects.
1841
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001842- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001843 exists). INT_MAX and LONG_MAX will always be defined, even if
1844 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001845
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001846- PyFloat_FromString takes a second argument, pend, that was
1847 effectively useless. It is now officially useless but preserved for
1848 backwards compatibility. If the pend argument is not NULL, *pend is
1849 set to NULL.
1850
1851- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1852 for the attribute name. See note on getattr() above.
1853
1854- A few bug fixes to argument processing for Unicode.
1855 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1856 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1857 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001858 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001859
1860- Py_BuildValue accepts B format (for bgen-generated code).
1861
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001862
Jeremy Hylton1b618592000-09-26 05:32:36 +00001863Internals
1864
1865- On Unix, fix code for finding Python installation directory so that
1866 it works when argv[0] is a relative path.
1867
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001868- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001869 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001870 rather than by generating a copy of the object.
1871
Tim Peters482c0212000-09-26 06:33:09 +00001872- Several of the internal Unicode tables are much smaller now, and
1873 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001874
Jeremy Hylton97693b02000-09-26 17:42:51 +00001875- In the garbage collector: Fixed bug in collection of tuples. Fixed
1876 bug that caused some instances to be removed from the container set
1877 while they were still live. Fixed parsing in gc.set_debug() for
1878 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001879
1880- Fixed refcount problem in instance deallocation that only occurred
1881 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1882
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001883- On Windows, getpythonregpath is now protected against null data in
1884 registry key.
1885
1886- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001887 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001888
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001889
Jeremy Hylton1b618592000-09-26 05:32:36 +00001890Build and platform-specific issues
1891
1892- Better support of GNU Pth via --with-pth configure option.
1893
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001894- Python/C API now properly exposed to dynamically-loaded extension
1895 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001896
1897- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1898 Don't define MS_SYNC to be zero when it is undefined. Added missing
1899 prototypes in posixmodule.c.
1900
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001901- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001902 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001903
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001904- Fix largefile support on older NetBSD systems and OpenBSD by adding
1905 define for TELL64.
1906
1907
1908Tools and other miscellany
1909
1910- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1911
1912- freeze: The modulefinder now works with 2.0 opcodes.
1913
Tim Petersa3a3a032000-11-30 05:22:44 +00001914- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001915 Move hackery of sys.argv until after the Tk instance has been
1916 created, which allows the application-specific Tkinter
1917 initialization to be executed if present; also pass an explicit
1918 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001919
Jeremy Hylton1b618592000-09-26 05:32:36 +00001920
1921What's new in 2.0 beta 1?
1922=========================
1923
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001924Source Incompatibilities
1925------------------------
1926
1927None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1928such as single-argument append(), connect() and bind(), and changes to
1929str(long) and repr(float).
1930
1931
1932Binary Incompatibilities
1933------------------------
1934
1935- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1936with Python 2.0; these extensions will have to be rebuilt for Python
19372.0.
1938
1939- On Windows, attempting to import a third party extension built for
1940Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1941can do about this. Check your PYTHONPATH environment variable!
1942
1943- Python bytecode files (*.pyc and *.pyo) are not compatible between
1944releases.
1945
1946
1947Overview of Changes Since 1.6
1948-----------------------------
1949
1950There are many new modules (including brand new XML support through
1951the xml package, and i18n support through the gettext module); a list
1952of all new modules is included below. Lots of bugs have been fixed.
1953
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001954The process for making major new changes to the language has changed
1955since Python 1.6. Enhancements must now be documented by a Python
1956Enhancement Proposal (PEP) before they can be accepted.
1957
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001958There are several important syntax enhancements, described in more
1959detail below:
1960
1961 - Augmented assignment, e.g. x += 1
1962
1963 - List comprehensions, e.g. [x**2 for x in range(10)]
1964
1965 - Extended import statement, e.g. import Module as Name
1966
1967 - Extended print statement, e.g. print >> file, "Hello"
1968
1969Other important changes:
1970
1971 - Optional collection of cyclical garbage
1972
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001973Python Enhancement Proposal (PEP)
1974---------------------------------
1975
1976PEP stands for Python Enhancement Proposal. A PEP is a design
1977document providing information to the Python community, or describing
1978a new feature for Python. The PEP should provide a concise technical
1979specification of the feature and a rationale for the feature.
1980
1981We intend PEPs to be the primary mechanisms for proposing new
1982features, for collecting community input on an issue, and for
1983documenting the design decisions that have gone into Python. The PEP
1984author is responsible for building consensus within the community and
1985documenting dissenting opinions.
1986
1987The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001988
1989Augmented Assignment
1990--------------------
1991
1992This must have been the most-requested feature of the past years!
1993Eleven new assignment operators were added:
1994
Guido van Rossume905e952000-09-05 12:42:46 +00001995 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001996
1997For example,
1998
1999 A += B
2000
2001is similar to
2002
2003 A = A + B
2004
2005except that A is evaluated only once (relevant when A is something
2006like dict[index].attr).
2007
2008However, if A is a mutable object, A may be modified in place. Thus,
2009if A is a number or a string, A += B has the same effect as A = A+B
2010(except A is only evaluated once); but if a is a list, A += B has the
2011same effect as A.extend(B)!
2012
2013Classes and built-in object types can override the new operators in
2014order to implement the in-place behavior; the not-in-place behavior is
2015used automatically as a fallback when an object doesn't implement the
2016in-place behavior. For classes, the method name is derived from the
2017method name for the corresponding not-in-place operator by inserting
2018an 'i' in front of the name, e.g. __iadd__ implements in-place
2019__add__.
2020
2021Augmented assignment was implemented by Thomas Wouters.
2022
2023
2024List Comprehensions
2025-------------------
2026
2027This is a flexible new notation for lists whose elements are computed
2028from another list (or lists). The simplest form is:
2029
2030 [<expression> for <variable> in <sequence>]
2031
Guido van Rossum56db0952000-09-06 23:34:25 +00002032For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002033This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002034
2035You can also add a condition:
2036
2037 [<expression> for <variable> in <sequence> if <condition>]
2038
2039For example, [w for w in words if w == w.lower()] would yield the list
2040of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002041than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002042
2043You can also have nested for loops and more than one 'if' clause. For
2044example, here's a function that flattens a sequence of sequences::
2045
2046 def flatten(seq):
2047 return [x for subseq in seq for x in subseq]
2048
2049 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2050
2051This prints
2052
2053 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2054
2055List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002056Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002057
2058
2059Extended Import Statement
2060-------------------------
2061
2062Many people have asked for a way to import a module under a different
2063name. This can be accomplished like this:
2064
2065 import foo
2066 bar = foo
2067 del foo
2068
2069but this common idiom gets old quickly. A simple extension of the
2070import statement now allows this to be written as follows:
2071
2072 import foo as bar
2073
2074There's also a variant for 'from ... import':
2075
2076 from foo import bar as spam
2077
2078This also works with packages; e.g. you can write this:
2079
2080 import test.regrtest as regrtest
2081
2082Note that 'as' is not a new keyword -- it is recognized only in this
2083context (this is only possible because the syntax for the import
2084statement doesn't involve expressions).
2085
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002086Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002087
2088
2089Extended Print Statement
2090------------------------
2091
2092Easily the most controversial new feature, this extension to the print
2093statement adds an option to make the output go to a different file
2094than the default sys.stdout.
2095
2096For example, to write an error message to sys.stderr, you can now
2097write:
2098
2099 print >> sys.stderr, "Error: bad dog!"
2100
2101As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002102evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002103
2104 print >> None, "Hello world"
2105
2106is equivalent to
2107
2108 print "Hello world"
2109
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002110Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002111
2112
2113Optional Collection of Cyclical Garbage
2114---------------------------------------
2115
2116Python is now equipped with a garbage collector that can hunt down
2117cyclical references between Python objects. It's no replacement for
2118reference counting; in fact, it depends on the reference counts being
2119correct, and decides that a set of objects belong to a cycle if all
2120their reference counts can be accounted for from their references to
2121each other. This devious scheme was first proposed by Eric Tiedemann,
2122and brought to implementation by Neil Schemenauer.
2123
2124There's a module "gc" that lets you control some parameters of the
2125garbage collection. There's also an option to the configure script
2126that lets you enable or disable the garbage collection. In 2.0b1,
2127it's on by default, so that we (hopefully) can collect decent user
2128experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002129performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002130off by default in the final 2.0 release.
2131
2132
2133Smaller Changes
2134---------------
2135
2136A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2137map(None, seq1, seq2, ...) when the sequences have the same length;
2138i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2139the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002140zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002141
2142sys.version_info is a tuple (major, minor, micro, level, serial).
2143
2144Dictionaries have an odd new method, setdefault(key, default).
2145dict.setdefault(key, default) returns dict[key] if it exists; if not,
2146it sets dict[key] to default and returns that value. Thus:
2147
2148 dict.setdefault(key, []).append(item)
2149
2150does the same work as this common idiom:
2151
2152 if not dict.has_key(key):
2153 dict[key] = []
2154 dict[key].append(item)
2155
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002156There are two new variants of SyntaxError that are raised for
2157indentation-related errors: IndentationError and TabError.
2158
2159Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2160escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002161
2162The limits on the size of expressions and file in Python source code
2163have been raised from 2**16 to 2**32. Previous versions of Python
2164were limited because the maximum argument size the Python VM accepted
2165was 2**16. This limited the size of object constructor expressions,
2166e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2167limit was raised thanks to a patch by Charles Waldman that effectively
2168fixes the problem. It is now much more likely that you will be
2169limited by available memory than by an arbitrary limit in Python.
2170
2171The interpreter's maximum recursion depth can be modified by Python
2172programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2173limit is the maximum number of recursive calls that can be made by
2174Python code. The limit exists to prevent infinite recursion from
2175overflowing the C stack and causing a core dump. The default value is
21761000. The maximum safe value for a particular platform can be found
2177by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002178
2179New Modules and Packages
2180------------------------
2181
2182atexit - for registering functions to be called when Python exits.
2183
2184imputil - Greg Stein's alternative API for writing custom import
2185hooks.
2186
2187pyexpat - an interface to the Expat XML parser, contributed by Paul
2188Prescod.
2189
2190xml - a new package with XML support code organized (so far) in three
2191subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2192would fill a volume. There's a special feature whereby a
2193user-installed package named _xmlplus overrides the standard
2194xmlpackage; this is intended to give the XML SIG a hook to distribute
2195backwards-compatible updates to the standard xml package.
2196
2197webbrowser - a platform-independent API to launch a web browser.
2198
2199
Guido van Rossume905e952000-09-05 12:42:46 +00002200Changed Modules
2201---------------
2202
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002203array -- new methods for array objects: count, extend, index, pop, and
2204remove
2205
2206binascii -- new functions b2a_hex and a2b_hex that convert between
2207binary data and its hex representation
2208
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002209calendar -- Many new functions that support features including control
2210over which day of the week is the first day, returning strings instead
2211of printing them. Also new symbolic constants for days of week,
2212e.g. MONDAY, ..., SUNDAY.
2213
2214cgi -- FieldStorage objects have a getvalue method that works like a
2215dictionary's get method and returns the value attribute of the object.
2216
2217ConfigParser -- The parser object has new methods has_option,
2218remove_section, remove_option, set, and write. They allow the module
2219to be used for writing config files as well as reading them.
2220
2221ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002222optionally support the RFC 959 REST command.
2223
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002224gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002225
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002226httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2227the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002228
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002229locale -- implement getdefaultlocale for Win32 and Macintosh
2230
2231marshal -- no longer dumps core when marshaling deeply nested or
2232recursive data structures
2233
2234os -- new functions isatty, seteuid, setegid, setreuid, setregid
2235
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002236os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2237support under Unix.
2238
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002239os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002240
2241os.path -- fix semantics of os.path.commonprefix
2242
2243smtplib -- support for sending very long messages
2244
2245socket -- new function getfqdn()
2246
2247readline -- new functions to read, write and truncate history files.
2248The readline section of the library reference manual contains an
2249example.
2250
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002251select -- add interface to poll system call
2252
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002253shutil -- new copyfileobj function
2254
2255SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2256HTTP server.
2257
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002258Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002259
2260urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002261e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002262
2263whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002264
2265
2266Obsolete Modules
2267----------------
2268
2269None. However note that 1.6 made a whole slew of modules obsolete:
2270stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2271poly, zmod, strop, util, whatsound.
2272
2273
2274Changed, New, Obsolete Tools
2275----------------------------
2276
Tim Peters8b092332000-09-05 20:15:25 +00002277None.
Guido van Rossume905e952000-09-05 12:42:46 +00002278
2279
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002280C-level Changes
2281---------------
2282
2283Several cleanup jobs were carried out throughout the source code.
2284
2285All C code was converted to ANSI C; we got rid of all uses of the
2286Py_PROTO() macro, which makes the header files a lot more readable.
2287
2288Most of the portability hacks were moved to a new header file,
2289pyport.h; several other new header files were added and some old
2290header files were removed, in an attempt to create a more rational set
2291of header files. (Few of these ever need to be included explicitly;
2292they are all included by Python.h.)
2293
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002294Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002295and Win64, especially for the new Intel Itanium processor. Mick also
2296added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002297
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002298The C APIs to return an object's size have been update to consistently
2299use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2300previous versions, the abstract interfaces used PyXXX_Length and the
2301concrete interfaces used PyXXX_Size. The old names,
2302e.g. PyObject_Length, are still available for backwards compatibility
2303at the API level, but are deprecated.
2304
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002305The PyOS_CheckStack function has been implemented on Windows by
2306Fredrik Lundh. It prevents Python from failing with a stack overflow
2307on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002308
2309The GC changes resulted in creation of two new slots on object,
2310tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002311the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002312
2313The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002314C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002315
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002316PyErr_Format has been updated to automatically calculate the size of
2317the buffer needed to hold the formatted result string. This change
2318prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002319
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002320New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002321
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002322PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2323that are the same as their non-Ex counterparts except they take an
2324extra flag argument that tells them to close the file when done.
2325
2326XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002327
Tim Peters8b092332000-09-05 20:15:25 +00002328
2329Windows Changes
2330---------------
2331
2332New popen2/popen3/peopen4 in os module (see Changed Modules above).
2333
2334os.popen is much more usable on Windows 95 and 98. See Microsoft
2335Knowledge Base article Q150956. The Win9x workaround described there
2336is implemented by the new w9xpopen.exe helper in the root of your
2337Python installation. Note that Python uses this internally; it is not
2338a standalone program.
2339
2340Administrator privileges are no longer required to install Python
2341on Windows NT or Windows 2000. If you have administrator privileges,
2342Python's registry info will be written under HKEY_LOCAL_MACHINE.
2343Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002344under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002345uses of Python, but will prevent some advanced uses from working
2346(for example, running a Python script as an NT service, or possibly
2347from CGI).
2348
2349[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2350installer; instead, it installs the needed Tcl/Tk files directly in the
2351Python directory. If you already have a Tcl/Tk installation, this
2352wastes some disk space (about 4 Megs) but avoids problems with
2353conflicting Tcl/Tk installations, and makes it much easier for Python
2354to ensure that Tcl/Tk can find all its files.
2355
2356[This was new in 1.6] The Windows installer now installs by default in
2357\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2358
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002359
2360Updates to the changes between 1.5.2 and 1.6
2361--------------------------------------------
2362
2363The 1.6 NEWS file can't be changed after the release is done, so here
2364is some late-breaking news:
2365
2366New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2367and changes to getlocale() and setlocale().
2368
2369The new module is now enabled per default.
2370
2371It is not true that the encodings codecs cannot be used for normal
2372strings: the string.encode() (which is also present on 8-bit strings
2373!) allows using them for 8-bit strings too, e.g. to convert files from
2374cp1252 (Windows) to latin-1 or vice-versa.
2375
2376Japanese codecs are available from Tamito KAJIYAMA:
2377http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2378
2379
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002380======================================================================