blob: b282559bf5a57aa5f5277c0bdadc992cd318ee74 [file] [log] [blame]
Tim Petersb07352e2001-09-08 01:25:47 +00001What's New in Python 2.2a4?
2===========================
3
4Core
5
6Library
7
Tim Peters16a77ad2001-09-08 04:00:12 +00008- operator.indexOf() (PySequence_Index() in the C API) now works with any
9 iterable object.
10
Tim Petersb07352e2001-09-08 01:25:47 +000011Tools
12
13Build
14
15C API
16
17New platforms
18
19Tests
20
21Windows
22
23
Tim Petersedc99312001-08-22 21:36:50 +000024What's New in Python 2.2a3?
25===========================
26
27Core
28
Tim Peters9fffa3e2001-09-04 05:14:19 +000029- Conversion of long to float now raises OverflowError if the long is too
30 big to represent as a C double.
31
Tim Peters32f453e2001-09-03 08:35:41 +000032- The 3-argument builtin pow() no longer allows a third non-None argument
33 if either of the first two arguments is a float, or if both are of
34 integer types and the second argument is negative (in which latter case
35 the arguments are converted to float, so this is really the same
36 restriction).
37
Tim Peters5d2b77c2001-09-03 05:47:38 +000038- The builtin dir() now returns more information, and sometimes much
39 more, generally naming all attributes of an object, and all attributes
40 reachable from the object via its class, and from its class's base
41 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
42 an empty list. In 2.2a3,
43
44 >>> dir([])
45 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
46 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
47 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
48 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
49 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
50 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
51 'reverse', 'sort']
52
53 dir(module) continues to return only the module's attributes, though.
54
Tim Petersbdee63f2001-09-02 03:40:59 +000055- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +000056 than raising OverflowError. This is a partial implementation of PEP
57 237. You can use -Wdefault::OverflowWarning to enable a warning for
58 this situation, and -Werror::OverflowWarning to revert to the old
59 OverflowError exception.
60
Guido van Rossum61c345f2001-09-04 03:26:15 +000061- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +000062 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +000063 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
64 -Qold, meaning the / operator has its classic meaning and no
65 warnings are issued. Using -Qwarn issues a run-time warning about
66 all uses of classic division for int and long arguments; -Qwarnall
67 also warns about classic division for float and complex arguments
68 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
69 new division by default, but only in the __main__ module. You can
70 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
71 __main__ module new division, and warns about classic division
72 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +000073
Tim Petersbdee63f2001-09-02 03:40:59 +000074- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +000075 long, float, str, unicode, and tuple. (The types complex, list and
76 dictionary can also be subclassed; this was introduced earlier.)
77 Note that restrictions apply when subclassing immutable built-in
78 types: you can only affect the value of the instance by overloading
79 __new__. You can add mutable attributes, and the subclass instances
80 will have a __dict__ attribute, but you cannot change the "value"
81 (as implemented by the base class) of an immutable subclass instance
82 once it is created.
83
Guido van Rossumaaf80c82001-09-02 13:44:35 +000084- The dictionary constructor now takes an optional argument, a
85 mapping-like object, and initializes the dictionary from its
86 (key, value) pairs.
87
Tim Petersbdee63f2001-09-02 03:40:59 +000088- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +000089 "cooperative super calls" in a multiple inheritance setting. For an
90 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
91
Guido van Rossum8d7234d2001-09-06 22:02:58 +000092- A new built-in type, property, has been added. This enables the
93 creation of "properties". These are attributes implemented by
94 getter and setter functions (or only one of these for read-only or
95 write-only attributes), without the need to override __getattr__.
96 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +000097
Tim Petersbdee63f2001-09-02 03:40:59 +000098- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +000099 liberalized, to allow leading zeroes. Examples of literals now
100 legal that were SyntaxErrors before:
101
102 00.0 0e3 0100j 07.5 00000000000000000008.
103
Tim Petersbdee63f2001-09-02 03:40:59 +0000104- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000105 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
106
Tim Petersedc99312001-08-22 21:36:50 +0000107Library
108
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000109- telnetlib includes symbolic names for the options, and support for
110 setting an option negotiation callback.
111
Tim Petersa40c7932001-09-05 22:36:56 +0000112- The new C standard no longer requires that math libraries set errno to
113 ERANGE on overflow. For platform libraries that exploit this new
114 freedom, Python's overflow-checking was wholly broken. A new overflow-
115 checking scheme attempts to repair that, but may not be reliable on all
116 platforms (C doesn't seem to provide anything both useful and portable
117 in this area anymore).
118
Martin v. Löwis44f86962001-09-05 13:44:54 +0000119- Asynchronous timeout actions are available through the new class
120 threading.Timer.
121
Tim Peters78526162001-09-05 00:53:45 +0000122- math.log and math.log10 now return sensible results for even huge
123 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
124
Tim Petersbdee63f2001-09-02 03:40:59 +0000125- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000126 currently held. See the docs for the imp module.
127
Tim Petersbdee63f2001-09-02 03:40:59 +0000128- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000129 dumps containing ints written on platforms where Python ints are 8 bytes.
130 When read on a box where Python ints are 4 bytes, such values are
131 converted to Python longs.
132
Tim Petersbdee63f2001-09-02 03:40:59 +0000133- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000134 code objects is no longer allowed. This plugs a security hole.
135
Steve Purcell6091cd62001-09-06 16:05:17 +0000136- unittest.TestResult instances no longer store references to tracebacks
137 generated by test failures. This prevents unexpected dangling references
138 to objects that should be garbage collected between tests.
139
Tim Petersedc99312001-08-22 21:36:50 +0000140Tools
141
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000142- Tools/scripts/fixdiv.py has been added which can be used to fix
143 division operators as per PEP 238.
144
Tim Petersedc99312001-08-22 21:36:50 +0000145Build
146
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000147- If you are an adventurous person using Mac OS X you may want to look at
148 Mac/OSX. There is a Makefile there that will build Python as a real Mac
149 application, which can be used for experimenting with Carbon or Cocoa.
150 Discussion of this on pythonmac-sig, please.
151
Tim Peters7eea37e2001-09-04 22:08:56 +0000152C API
153
154- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000155
Tim Peters9fffa3e2001-09-04 05:14:19 +0000156- Note that PyLong_AsDouble can fail! This has always been true, but no
157 callers checked for it. It's more likely to fail now, because overflow
158 errors are properly detected now. The proper way to check:
159
160 double x = PyLong_AsDouble(some_long_object);
161 if (x == -1.0 && PyErr_Occurred()) {
162 /* The conversion failed. */
163 }
164
Tim Petersbdee63f2001-09-02 03:40:59 +0000165- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000166 compile but will not participate in GC. To upgrade an extension
167 module:
168
169 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000170
Neil Schemenauer4042c692001-08-30 15:38:01 +0000171 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
172 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000173
Neil Schemenauer4042c692001-08-30 15:38:01 +0000174 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
175 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000176
Neil Schemenauer4042c692001-08-30 15:38:01 +0000177 - remove PyGC_HEAD_SIZE from object size calculations
178
179 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
180
Tim Petersbdee63f2001-09-02 03:40:59 +0000181- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000182 These can be used safely to construct string objects from a
183 sprintf-style format string (similar to the format string supported
184 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000185
Tim Petersedc99312001-08-22 21:36:50 +0000186New platforms
187
Tim Petersb7da0902001-09-02 23:01:43 +0000188- Stephen Hansen contributed patches sufficient to get a clean compile
189 under Borland C (Windows), but he reports problems running it and ran
190 out of time to complete the port. Volunteers? Expect a MemoryError
191 when importing the types module; this is probably shallow, and
192 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000193
Tim Petersedc99312001-08-22 21:36:50 +0000194Tests
195
196Windows
197
Tim Peters6e13a562001-09-06 00:32:15 +0000198- Large file support is now enabled on Win32 platforms as well as on
199 Win64. This means that, for example, you can use f.tell() and f.seek()
200 to manipulate files larger than 2 gigabytes (provided you have enough
201 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000202 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
203 filesize limit, and large file support makes no difference there.
204 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
205 NTFS has no practical limit on file size, and files of any size can be
206 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000207
Tim Petersbdee63f2001-09-02 03:40:59 +0000208- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000209 points to command.com (patch from Brian Quinlan).
210
Tim Petersedc99312001-08-22 21:36:50 +0000211
Tim Peters20f51a72001-07-21 02:31:40 +0000212What's New in Python 2.2a2?
213===========================
214
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000215Build
216
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000217- Tim Peters developed a brand new Windows installer using Wise 8.1,
218 generously donated to us by Wise Solutions.
219
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000220- configure supports a new option --enable-unicode, with the values
221 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
222 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000223
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000224- A new configure option --enable-framework builds a Mac OS X framework,
225 which "make frameworkinstall" will install. This provides a starting
226 point for more mac-like functionality, join pythonmac-sig@python.org
227 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000228
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000229- The NeXT platform is no longer supported.
230
231- The `new' module is now statically linked.
232
Tim Peters0afb6092001-08-15 06:06:44 +0000233Tools
234
235- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000236 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000237 the module docstring for details.
238
Tim Peters20f51a72001-07-21 02:31:40 +0000239Tests
240
Tim Peters5e824c32001-08-12 22:25:01 +0000241- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000242 platforms, allowing to give clearer test result output. regrtest
243 also has optional --use/-u switch to run normally disabled tests
244 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000245
Tim Peters20f51a72001-07-21 02:31:40 +0000246- Several new tests in the standard test suite, with special thanks to
247 Nick Mathewson.
248
249Core
250
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000251- The floor division operator // has been added as outlined in PEP
252 238. The / operator still provides classic division (and will until
253 Python 3.0) unless "from __future__ import division" is included, in
254 which case the / operator will provide true division. The operator
255 module provides truediv() and floordiv() functions. Augmented
256 assignment variants are included, as are the equivalent overloadable
257 methods and C API methods. See the PEP for a full discussion:
258 <http://python.sf.net/peps/pep-0238.html>
259
Tim Peters6cd6a822001-08-17 22:11:27 +0000260- Future statements are now effective in simulated interactive shells
261 (like IDLE). This should "just work" by magic, but read Michael
262 Hudson's "Future statements in simulated shells" PEP 264 for full
263 details: <http://python.sf.net/peps/pep-0264.html>.
264
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000265- The type/class unification (PEP 252-253) was integrated into the
266 trunk and is not so tentative any more (the exact specification of
267 some features is still tentative). A lot of work has done on fixing
268 bugs and adding robustness and features (performance still has to
269 come a long way).
270
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000271- Warnings about a mismatch in the Python API during extension import
272 now use the Python warning framework (which makes it possible to
273 write filters for these warnings).
274
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000275- A function's __dict__ (aka func_dict) will now always be a
276 dictionary. It used to be possible to delete it or set it to None,
277 but now both actions raise TypeErrors. It is still legal to set it
278 to a dictionary object. Getting func.__dict__ before any attributes
279 have been assigned now returns an empty dictionary instead of None.
280
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000281- A new command line option, -E, was added which disables the use of
282 all environment variables, or at least those that are specifically
283 significant to Python. Usually those have a name starting with
284 "PYTHON". This was used to fix a problem where the tests fail if
285 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
286 older distribution.
287
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000288Library
289
Tim Peters5e824c32001-08-12 22:25:01 +0000290- New class Differ and new functions ndiff() and restore() in difflib.py.
291 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000292 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000293
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000294- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
295 value using the minimal quoting required for the value; more
296 reliable than using xml.sax.saxutils.escape() for attribute values.
297
298- Readline completion support for cmd.Cmd was added.
299
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000300- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
301
302- Added function threading.BoundedSemaphore()
303
304- Added Ka-Ping Yee's cgitb.py module.
305
306- The `new' module now exposes the CO_xxx flags.
307
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000308New platforms
309
310C API
311
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000312- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
313 which provide a cross-platform implementations for the
314 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
315 the standard sprintf() and vsprintf() C lib APIs, these versions
316 apply bounds checking on the used buffer which enhances protection
317 against buffer overruns.
318
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000319- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000320 and extensions using different Unicode widths is rendered next to
321 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000322 will result in an ImportError. Unicode extensions writers must make
323 sure to check the Unicode width compatibility in their extensions by
324 using at least one of the mangled Unicode APIs in the extension.
325
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000326- Two new flags METH_NOARGS and METH_O are available in method definition
327 tables to simplify implementation of methods with no arguments and a
328 single untyped argument. Calling such methods is more efficient than
329 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
330 deprecated.
331
Tim Petersc1731372001-08-04 08:12:36 +0000332Windows
333
334- "import module" now compiles module.pyw if it exists and nothing else
335 relevant is found.
336
Tim Peters20f51a72001-07-21 02:31:40 +0000337
Guido van Rossum55a78992001-07-17 17:22:32 +0000338What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000339===========================
340
341Core
Tim Petersa814db52001-05-14 07:05:58 +0000342
Tim Peters6d6c1a32001-08-02 04:15:00 +0000343- TENTATIVELY, a large amount of code implementing much of what's
344 described in PEP 252 (Making Types Look More Like Classes) and PEP
345 253 (Subtyping Built-in Types) was added. This will be released
346 with Python 2.2a1. Documentation will be provided separately
347 through http://www.python.org/2.2/. The purpose of releasing this
348 with Python 2.2a1 is to test backwards compatibility. It is
349 possible, though not likely, that a decision is made not to release
350 this code as part of 2.2 final, if any serious backwards
351 incompapatibilities are found during alpha testing that cannot be
352 repaired.
353
Guido van Rossum55a78992001-07-17 17:22:32 +0000354- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000355 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000356 more 'yield' statements. See PEP 255. Since this adds a new
357 keyword to the language, this feature must be enabled by including a
358 future statement: "from __future__ import generators" (see PEP 236).
359 Generators will become a standard feature in a future release
360 (probably 2.3). Without this future statement, 'yield' remains an
361 ordinary identifier, but a warning is issued each time it is used.
362 (These warnings currently don't conform to the warnings framework of
363 PEP 230; we intend to fix this in 2.2a2.)
364
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000365- The UTF-16 codec was modified to be more RFC compliant. It will now
366 only remove BOM characters at the start of the string and then
367 only if running in native mode (UTF-16-LE and -BE won't remove a
368 leading BMO character).
369
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000370- Strings now have a new method .decode() to complement the already
371 existing .encode() method. These two methods provide direct access
372 to the corresponding decoders and encoders of the registered codecs.
373
374 To enhance the usability of the .encode() method, the special
375 casing of Unicode object return values was dropped (Unicode objects
376 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000377
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000378 Both methods will now return whatever the codec in charge of the
379 requested encoding returns as object, e.g. Unicode codecs will
380 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
381 will return u"äöü"). This enables codec writer to create codecs
382 for various simple to use conversions.
383
384 New codecs were added to demonstrate these new features (the .encode()
385 and .decode() columns indicate the type of the returned objects):
386
387 Name | .encode() | .decode() | Description
388 ----------------------------------------------------------------------
389 uu | string | string | UU codec (e.g. for email)
390 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000391 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000392 zlib | string | string | zlib compression
393 hex | string | string | 2-byte hex codec
394 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
395
Mark Hammond2a0af792001-05-14 03:09:36 +0000396- Some operating systems now support the concept of a default Unicode
397 encoding for file system operations. Notably, Windows supports 'mbcs'
398 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000399 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000400 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000401
402 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000403 functions that return filenames (such as os.listdir()) to return Python
404 string objects pre-encoded using the default file system encoding for
405 the platform. As this encoding is likely to be different from Python's
406 default encoding, converting this name to a Unicode object before passing
407 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000408 would attempt to use its default encoding (generally ASCII) rather than
409 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000410
Tim Petersa814db52001-05-14 07:05:58 +0000411 In general, this change simply removes surprises when working with
412 Unicode and the file system, making these operations work as you expect,
413 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000414 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000415
Tim Peters61dff2b2001-05-08 15:43:37 +0000416- Float (and complex) literals in source code were evaluated to full
417 precision only when running from a .py file; the same code loaded from a
418 .pyc (or .pyo) file could suffer numeric differences starting at about the
419 12th significant decimal digit. For example, on a machine with IEEE-754
420 floating arithmetic,
421
422 x = 9007199254740992.0
423 print long(x)
424
425 printed 9007199254740992 if run directly from .py, but 9007199254740000
426 if from a compiled (.pyc or .pyo) file. This was due to marshal using
427 str(float) instead of repr(float) when building code objects. marshal
428 now uses repr(float) instead, which should reproduce floats to full
429 machine precision (assuming the platform C float<->string I/O conversion
430 functions are of good quality).
431
432 This may cause floating-point results to change in some cases, and
433 usually for the better, but may also cause numerically unstable
434 algorithms to break.
435
Tim Peters2f228e72001-05-13 00:19:31 +0000436- The implementation of dicts suffers fewer collisions, which has speed
437 benefits. However, the order in which dict entries appear in dict.keys(),
438 dict.values() and dict.items() may differ from previous releases for a
439 given dict. Nothing is defined about this order, so no program should
440 rely on it. Nevertheless, it's easy to write test cases that rely on the
441 order by accident, typically because of printing the str() or repr() of a
442 dict to an "expected results" file. See Lib/test/test_support.py's new
443 sortdict(dict) function for a simple way to display a dict in sorted
444 order.
445
Tim Peters7a3bfc32001-06-12 01:22:22 +0000446- Many other small changes to dicts were made, resulting in faster
447 operation along the most common code paths.
448
Guido van Rossum10315822001-05-01 20:54:30 +0000449- Dictionary objects now support the "in" operator: "x in dict" means
450 the same as dict.has_key(x).
451
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000452- The update() method of dictionaries now accepts generic mapping
453 objects. Specifically the argument object must support the .keys()
454 and __getitem__() methods. This allows you to say, for example,
455 {}.update(UserDict())
456
Guido van Rossum10315822001-05-01 20:54:30 +0000457- Iterators were added; this is a generalized way of providing values
458 to a for loop. See PEP 234. There's a new built-in function iter()
459 to return an iterator. There's a new protocol to get the next value
460 from an iterator using the next() method (in Python) or the
461 tp_iternext slot (in C). There's a new protocol to get iterators
462 using the __iter__() method (in Python) or the tp_iter slot (in C).
463 Iterating (i.e. a for loop) over a dictionary generates its keys.
464 Iterating over a file generates its lines.
465
Tim Petersf553f892001-05-01 20:45:31 +0000466- The following functions were generalized to work nicely with iterator
467 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000468 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000469 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
470 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000471 join() method of strings
472 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000473 'x in y' and 'x not in y' (PySequence_Contains() in C API)
474 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000475 right-hand side of assignment statements with multiple targets, such as
476 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000477
Tim Petersd85e1022001-05-11 21:51:48 +0000478- Accessing module attributes is significantly faster (for example,
479 random.random or os.path or yourPythonModule.yourAttribute).
480
Tim Peterse63415e2001-05-08 04:38:29 +0000481- Comparing dictionary objects via == and != is faster, and now works even
482 if the keys and values don't support comparisons other than ==.
483
Tim Peters95bf9392001-05-10 08:32:44 +0000484- Comparing dictionaries in ways other than == and != is slower: there were
485 insecurities in the dict comparison implementation that could cause Python
486 to crash if the element comparison routines for the dict keys and/or
487 values mutated the dicts. Making the code bulletproof slowed it down.
488
Tim Peterseb28ef22001-06-02 05:27:19 +0000489- Collisions in dicts are resolved via a new approach, which can help
490 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000491 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000492 faster now. Thanks to Christian Tismer for pointing out the cause and
493 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000494
Tim Peters52e155e2001-06-16 05:42:57 +0000495- repr() is much faster for large containers (dict, list, tuple).
496
497
Tim Petersa814db52001-05-14 07:05:58 +0000498Library
499
Fred Drake960fdf92001-07-20 18:38:26 +0000500- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
501 were added to the string module. These a locale-indenpendent
502 constants, unlike letters, lowercase, and uppercase. These are now
503 use in appropriate locations in the standard library.
504
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000505- The flags used in dlopen calls can now be configured using
506 sys.setdlopenflags and queried using sys.getdlopenflags.
507
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000508- Fredrik Lundh's xmlrpclib is now a standard library module. This
509 provides full client-side XML-RPC support. In addition,
510 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
511 one asyncore-based). Thanks to Eric Raymond for the documentation.
512
Guido van Rossum643d3912001-07-05 14:46:25 +0000513- The xrange() object is simplified: it no longer supports slicing,
514 repetition, comparisons, efficient 'in' checking, the tolist()
515 method, or the start, stop and step attributes. See PEP 260.
516
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000517- A new function fnmatch.filter to filter lists of file names was added.
518
Barry Warsawffd674d2001-05-22 16:00:10 +0000519- calendar.py uses month and day names based on the current locale.
520
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000521- strop is now *really* obsolete (this was announced before with 1.6),
522 and issues DeprecationWarning when used (except for the four items
523 that are still imported into string.py).
524
Tim Petersa814db52001-05-14 07:05:58 +0000525- Cookie.py now sorts key+value pairs by key in output strings.
526
527- pprint.isrecursive(object) didn't correctly identify recursive objects.
528 Now it does.
529
Tim Peters95b3f782001-05-14 18:39:41 +0000530- pprint functions now much faster for large containers (tuple, list, dict).
531
Tim Peters7b9542a2001-06-10 23:40:19 +0000532- New 'q' and 'Q' format codes in the struct module, corresponding to C
533 types "long long" and "unsigned long long" (on Windows, __int64). In
534 native mode, these can be used only when the platform C compiler supports
535 these types (when HAVE_LONG_LONG is #define'd by the Python config
536 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000537 In standard mode, 'q' and 'Q' are supported on all platforms, and are
538 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000539
Guido van Rossum83213cc2001-06-12 16:48:52 +0000540- The site module installs a new built-in function 'help' that invokes
541 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
542 it displays a message reminding the user to use 'help()' or
543 'help(object)'.
544
Tim Petersa814db52001-05-14 07:05:58 +0000545Tests
546
547- New test_mutants.py runs dict comparisons where the key and value
548 comparison operators mutute the dicts randomly during comparison. This
549 rapidly causes Python to crash under earlier releases (not for the faint
550 of heart: it can also cause Win9x to freeze or reboot!).
551
552- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000553 pprint.isreadable() return sensible results. Also verifies that simple
554 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000555
Tim Peters4324aa32001-05-28 22:30:08 +0000556C API
557
558- Removed the unused last_is_sticky argument from the internal
559 _PyTuple_Resize(). If this affects you, you were cheating.
560
561
Guido van Rossum55a78992001-07-17 17:22:32 +0000562======================================================================
563
564
Guido van Rossumffe13be2001-04-16 18:46:45 +0000565What's New in Python 2.1 (final)?
566=================================
567
568We only changed a few things since the last release candidate, all in
569Python library code:
570
571- A bug in the locale module was fixed that affected locales which
572 define no grouping for numeric formatting.
573
574- A few bugs in the weakref module's implementations of weak
575 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
576 and the test suite was updated to check for these bugs.
577
578- An old bug in the os.path.walk() function (introduced in Python
579 2.0!) was fixed: a non-existent file would cause an exception
580 instead of being ignored.
581
582- Fixed a few bugs in the new symtable module found by Neil Norwitz's
583 PyChecker.
584
585
Guido van Rossum5b08f132001-04-16 02:05:23 +0000586What's New in Python 2.1c2?
587===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000588
Guido van Rossum5b08f132001-04-16 02:05:23 +0000589A flurry of small changes, and one showstopper fixed in the nick of
590time made it necessary to release another release candidate. The list
591here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000592
Guido van Rossum5b08f132001-04-16 02:05:23 +0000593Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000594
Guido van Rossum5b08f132001-04-16 02:05:23 +0000595- Tim discovered a nasty bug in the dictionary code, caused by
596 PyDict_Next() calling dict_resize(), and the GC code's use of
597 PyDict_Next() violating an assumption in dict_items(). This was
598 fixed with considerable amounts of band-aid, but the net effect is a
599 saner and more robust implementation.
600
601- Made a bunch of symbols static that were accidentally global.
602
603Build and Ports
604
605- The setup.py script didn't check for a new enough version of zlib
606 (1.1.3 is needed). Now it does.
607
608- Changed "make clean" target to also remove shared libraries.
609
610- Added a more general warning about the SGI Irix optimizer to README.
611
612Library
613
614- Fix a bug in urllib.basejoin("http://host", "../file.html") which
615 omitted the slash between host and file.html.
616
617- The mailbox module's _Mailbox class contained a completely broken
618 and undocumented seek() method. Ripped it out.
619
620- Fixed a bunch of typos in various library modules (urllib2, smtpd,
621 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
622
623- Fixed a few last-minute bugs in unittest.
624
625Extensions
626
627- Reverted the patch to the OpenSSL code in socketmodule.c to support
628 RAND_status() and the EGD, and the subsequent patch that tried to
629 fix it for pre-0.9.5 versions; the problem with the patch is that on
630 some systems it issues a warning whenever socket is imported, and
631 that's unacceptable.
632
633Tests
634
635- Fixed the pickle tests to work with "import test.test_pickle".
636
637- Tweaked test_locale.py to actually run the test Windows.
638
639- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
640 not "wb" (which is not a valid mode at all).
641
642- Fix pstats browser crashes. Import readline if it exists to make
643 the user interface nicer.
644
645- Add "import thread" to the top of test modules that import the
646 threading module (test_asynchat and test_threadedtempfile). This
647 prevents test failures caused by a broken threading module resulting
648 from a previously caught failed import.
649
650- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
651 needed on some platforms (e.g. Solaris 8) when the tests are run
652 twice in succession.
653
654- Skip rather than fail test_sunaudiodev if no audio device is found.
655
656
657What's New in Python 2.1c1?
658===========================
659
660This list was significantly updated when 2.1c2 was released; the 2.1c1
661release didn't mention most changes that were actually part of 2.1c1:
662
663Legal
664
665- Copyright was assigned to the Python Software Foundation (PSF) and a
666 PSF license (very similar to the CNRI license) was added.
667
668- The CNRI copyright notice was updated to include 2001.
669
670Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000671
Guido van Rossumc9932722001-04-12 02:31:27 +0000672- After a public outcry, assignment to __debug__ is no longer illegal;
673 instead, a warning is issued. It will become illegal in 2.2.
674
Guido van Rossum5b08f132001-04-16 02:05:23 +0000675- Fixed a core dump with "%#x" % 0, and changed the semantics so that
676 "%#x" now always prepends "0x", even if the value is zero.
677
678- Fixed some nits in the bytecode compiler.
679
680- Fixed core dumps when calling certain kinds of non-functions.
681
682- Fixed various core dumps caused by reference count bugs.
683
684Build and Ports
685
686- Use INSTALL_SCRIPT to install script files.
687
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000688- New port: SCO Unixware 7, by Billy G. Allie.
689
Guido van Rossum5b08f132001-04-16 02:05:23 +0000690- Updated RISCOS port.
691
692- Updated BeOS port and notes.
693
694- Various other porting problems resolved.
695
696Library
697
698- The TERMIOS and SOCKET modules are now truly obsolete and
699 unnecessary. Their symbols are incorporated in the termios and
700 socket modules.
701
702- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
703 better tests for pickling.
704
705- threading: make Condition.wait() robust against KeyboardInterrupt.
706
707- zipfile: add support to zipfile to support opening an archive
708 represented by an open file rather than a file name. Fix bug where
709 the archive was not properly closed. Fixed a bug in this bugfix
710 where flush() was called for a read-only file.
711
712- imputil: added an uninstall() method to the ImportManager.
713
714- Canvas: fixed bugs in lower() and tkraise() methods.
715
716- SocketServer: API change (added overridable close_request() method)
717 so that the TCP server can explicitly close the request.
718
719- pstats: Eric Raymond added a simple interactive statistics browser,
720 invoked when the module is run as a script.
721
722- locale: fixed a problem in format().
723
724- webbrowser: made it work when the BROWSER environment variable has a
725 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
726 KDE 2. Fixed some other nits.
727
728- unittest: changes to allow using a different exception than
729 AssertionError, and added a few more function aliases. Some other
730 small changes.
731
732- urllib, urllib2: fixed redirect problems and a coupleof other nits.
733
734- asynchat: fixed a critical bug in asynchat that slipped through the
735 2.1b2 release. Fixed another rare bug.
736
737- Fix some unqualified except: clauses (always a bad code example).
738
739XML
740
741- pyexpat: new API get_version_string().
742
743- Fixed some minidom bugs.
744
745Extensions
746
747- Fixed a core dump in _weakref. Removed the weakref.mapping()
748 function (it adds nothing to the API).
749
750- Rationalized the use of header files in the readline module, to make
751 it compile (albeit with some warnings) with the very recent readline
752 4.2, without breaking for earlier versions.
753
754- Hopefully fixed a buffering problem in linuxaudiodev.
755
756- Attempted a fix to make the OpenSSL support in the socket module
757 work again with pre-0.9.5 versions of OpenSSL.
758
759Tests
760
761- Added a test case for asynchat and asyncore.
762
763- Removed coupling between tests where one test failing could break
764 another.
765
766Tools
767
768- Ping added an interactive help browser to pydoc, fixed some nits
769 in the rest of the pydoc code, and added some features to his
770 inspect module.
771
772- An updated python-mode.el version 4.1 which integrates Ken
773 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
774 much nicer in XEmacs and Emacs. When stepping through your program
775 with pdb, in either the shell window or the *Python* window, the
776 source file and line will be tracked by an arrow. Very cool!
777
778- IDLE: syntax warnings in interactive mode are changed into errors.
779
780- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000781 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000782
783- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000784
Barry Warsaw11e89c72001-04-11 20:37:57 +0000785
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000786What's New in Python 2.1 beta 2?
787================================
788
Guido van Rossum053ae352001-03-22 14:17:21 +0000789(Unlisted are many fixed bugs, more documentation, etc.)
790
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000791Core language, builtins, and interpreter
792
Guido van Rossum053ae352001-03-22 14:17:21 +0000793- The nested scopes work (enabled by "from __future__ import
794 nested_scopes") is completed; in particular, the future now extends
795 into code executed through exec, eval() and execfile(), and into the
796 interactive interpreter.
797
798- When calling a base class method (e.g. BaseClass.__init__(self)),
799 this is now allowed even if self is not strictly spoken a class
800 instance (e.g. when using metaclasses or the Don Beaudry hook).
801
802- Slice objects are now comparable but not hashable; this prevents
803 dict[:] from being accepted but meaningless.
804
805- Complex division is now calculated using less braindead algorithms.
806 This doesn't change semantics except it's more likely to give useful
807 results in extreme cases. Complex repr() now uses full precision
808 like float repr().
809
810- sgmllib.py now calls handle_decl() for simple <!...> declarations.
811
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000812- It is illegal to assign to the name __debug__, which is set when the
813 interpreter starts. It is effectively a compile-time constant.
814
815- A warning will be issued if a global statement for a variable
816 follows a use or assignment of that variable.
817
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000818Standard library
819
Guido van Rossum053ae352001-03-22 14:17:21 +0000820- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
821 inspired by JUnit), is now part of the standard library. You now
822 have a choice of two testing frameworks: unittest requires you to
823 write testcases as separate code, doctest gathers them from
824 docstrings. Both approaches have their advantages and
825 disadvantages.
826
827- A new module Tix was added, which wraps the Tix extension library
828 for Tk. With that module, it is not necessary to statically link
829 Tix with _tkinter, since Tix will be loaded with Tcl's "package
830 require" command. See Demo/tix/.
831
832- tzparse.py is now obsolete.
833
834- In gzip.py, the seek() and tell() methods are removed -- they were
835 non-functional anyway, and it's better if callers can test for their
836 existence with hasattr().
837
838Python/C API
839
840- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
841 that's already in the dictionary during a PyDict_Next() iteration.
842 This used to fail occasionally when a dictionary resize operation
843 could be triggered that would rehash all the keys. All other
844 modifications to the dictionary are still off-limits during a
845 PyDict_Next() iteration!
846
847- New extended APIs related to passing compiler variables around.
848
849- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
850 implement isinstance() and issubclass().
851
852- Py_BuildValue() now has a "D" conversion to create a Python complex
853 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000854
Fred Drake4e262a92001-03-22 18:26:47 +0000855- Extensions types which support weak references must now set the
856 field allocated for the weak reference machinery to NULL themselves;
857 this is done to avoid the cost of checking each object for having a
858 weakly referencable type in PyObject_INIT(), since most types are
859 not weakly referencable.
860
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000861- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
862 free variables and cell variables to and from the frame's f_locals.
863
864- Variants of several functions defined in pythonrun.h have been added
865 to support the nested_scopes future statement. The variants all end
866 in Flags and take an extra argument, a PyCompilerFlags *; examples:
867 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
868 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000869 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000870
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000871Distutils
872
873- the sdist command now writes a PKG-INFO file, as described in PEP 241,
874 into the release tree.
875
Tim Peters0e57abf2001-05-02 07:39:38 +0000876- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000877 (an uninstaller, more customization of the installer's display)
878
879- from Jack Jansen: added Mac-specific code to generate a dialog for
880 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000881 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000882 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000883
884- added 'platforms' and 'keywords' to the set of metadata that can be
885 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000886
887- applied patches from Jason Tishler to make the compiler class work with
888 Cygwin.
889
890
Tim Peters2fe289a2001-03-01 22:19:38 +0000891What's New in Python 2.1 beta 1?
892================================
Tim Petersd66595f2001-02-04 03:09:53 +0000893
894Core language, builtins, and interpreter
895
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000896- Following an outcry from the community about the amount of code
897 broken by the nested scopes feature introduced in 2.1a2, we decided
898 to make this feature optional, and to wait until Python 2.2 (or at
899 least 6 months) to make it standard. The option can be enabled on a
900 per-module basis by adding "from __future__ import nested_scopes" at
901 the beginning of a module (before any other statements, but after
902 comments and an optional docstring). See PEP 236 (Back to the
903 __future__) for a description of the __future__ statement. PEP 227
904 (Statically Nested Scopes) has been updated to reflect this change,
905 and to clarify the semantics in a number of endcases.
906
907- The nested scopes code, when enabled, has been hardened, and most
908 bugs and memory leaks in it have been fixed.
909
910- Compile-time warnings are now generated for a number of conditions
911 that will break or change in meaning when nested scopes are enabled:
912
913 - Using "from...import *" or "exec" without in-clause in a function
914 scope that also defines a lambda or nested function with one or
915 more free (non-local) variables. The presence of the import* or
916 bare exec makes it impossible for the compiler to determine the
917 exact set of local variables in the outer scope, which makes it
918 impossible to determine the bindings for free variables in the
919 inner scope. To avoid the warning about import *, change it into
920 an import of explicitly name object, or move the import* statement
921 to the global scope; to avoid the warning about bare exec, use
922 exec...in... (a good idea anyway -- there's a possibility that
923 bare exec will be deprecated in the future).
924
925 - Use of a global variable in a nested scope with the same name as a
926 local variable in a surrounding scope. This will change in
927 meaning with nested scopes: the name in the inner scope will
928 reference the variable in the outer scope rather than the global
929 of the same name. To avoid the warning, either rename the outer
930 variable, or use a global statement in the inner function.
931
Neil Schemenauera35c6882001-02-27 04:45:05 +0000932- An optional object allocator has been included. This allocator is
933 optimized for Python objects and should be faster and use less memory
934 than the standard system allocator. It is not enabled by default
935 because of possible thread safety problems. The allocator is only
936 protected by the Python interpreter lock and it is possible that some
937 extension modules require a thread safe allocator. The object
938 allocator can be enabled by providing the "--with-pymalloc" option to
939 configure.
940
Tim Petersd66595f2001-02-04 03:09:53 +0000941Standard library
942
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000943- pyexpat now detects the expat version if expat.h defines it. A
944 number of additional handlers are provided, which are only available
945 since expat 1.95. In addition, the methods SetParamEntityParsing and
946 GetInputContext of Parser objects are available with 1.95.x
947 only. Parser objects now provide the ordered_attributes and
948 specified_attributes attributes. A new module expat.model was added,
949 which offers a number of additional constants if 1.95.x is used.
950
951- xml.dom offers the new functions registerDOMImplementation and
952 getDOMImplementation.
953
954- xml.dom.minidom offers a toprettyxml method. A number of DOM
955 conformance issues have been resolved. In particular, Element now
956 has an hasAttributes method, and the handling of namespaces was
957 improved.
958
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000959- Ka-Ping Yee contributed two new modules: inspect.py, a module for
960 getting information about live Python code, and pydoc.py, a module
961 for interactively converting docstrings to HTML or text.
962 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000963 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000964 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
965 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000966
Tim Peters1eff7962001-03-01 02:31:33 +0000967- New library module difflib.py, primarily packaging the SequenceMatcher
968 class at the heart of the popular ndiff.py file-comparison tool.
969
970- doctest.py (a framework for verifying Python code examples in docstrings)
971 is now part of the std library.
972
Tim Petersd66595f2001-02-04 03:09:53 +0000973Windows changes
974
Guido van Rossume3955a82001-03-02 14:05:59 +0000975- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
976 small GUI that lets you browse the module docstrings using your
977 default web browser.
978
Tim Peters1eff7962001-03-01 02:31:33 +0000979- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
980 Platforms) is implemented. See
981
982 http://python.sourceforge.net/peps/pep-0235.html
983
984 for full details, especially the "Current Lower-Left Semantics" section.
985 The new Windows import rules are simpler than before:
986
987 A. If the PYTHONCASEOK environment variable exists, same as
988 before: silently accept the first case-insensitive match of any
989 kind; raise ImportError if none found.
990
991 B. Else search sys.path for the first case-sensitive match; raise
992 ImportError if none found.
993
994 The same rules have been implented on other platforms with case-
995 insensitive but case-preserving filesystems too (including Cygwin, and
996 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000997
Tim Peters25a9ce32001-02-19 07:06:36 +0000998- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
999 what it's supposed to do (and does do under NT and 2000) via direct
1000 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001001 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001002 all Win9x systems before.
1003
Tim Peters1eff7962001-03-01 02:31:33 +00001004- Build: Subproject _test (effectively) renamed to _testcapi.
1005
Tim Peters2fe289a2001-03-01 22:19:38 +00001006New platforms
1007
1008- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1009 Thanks to Steven Majewski!
1010
1011- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1012 Tishler!
1013
Guido van Rossum9089b272001-03-02 06:49:50 +00001014- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1015 Schwertberger! See RISCOS/README for more information -- it seems
1016 that because of the bizarre filename conventions on RISCOS, no port
1017 to that platform is easy. Note that the new variable os.endsep is
1018 silently supported in order to make life easier on this platform,
1019 but we don't advertise it because it's not worth for most folks to
1020 care about RISCOS portability.
1021
Tim Peters25a9ce32001-02-19 07:06:36 +00001022
Tim Petersd7b5e882001-01-25 03:36:26 +00001023What's New in Python 2.1 alpha 2?
1024=================================
Tim Peters40ead762001-01-27 05:35:26 +00001025
Tim Petersd7b5e882001-01-25 03:36:26 +00001026Core language, builtins, and interpreter
1027
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001028- Scopes nest. If a name is used in a function or class, but is not
1029 local, the definition in the nearest enclosing function scope will
1030 be used. One consequence of this change is that lambda statements
1031 could reference variables in the namespaces where the lambda is
1032 defined. In some unusual cases, this change will break code.
1033
1034 In all previous version of Python, names were resolved in exactly
1035 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001036 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001037 function A is defined within a function B, the names bound in B are
1038 not visible in A. The new rules make names bound in B visible in A,
1039 unless A contains a name binding that hides the binding in B.
1040
1041 Section 4.1 of the reference manual describes the new scoping rules
1042 in detail. The test script in Lib/test/test_scope.py demonstrates
1043 some of the effects of the change.
1044
1045 The new rules will cause existing code to break if it defines nested
1046 functions where an outer function has local variables with the same
1047 name as globals or builtins used by the inner function. Example:
1048
1049 def munge(str):
1050 def helper(x):
1051 return str(x)
1052 if type(str) != type(''):
1053 str = helper(str)
1054 return str.strip()
1055
1056 Under the old rules, the name str in helper() is bound to the
1057 builtin function str(). Under the new rules, it will be bound to
1058 the argument named str and an error will occur when helper() is
1059 called.
1060
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001061- The compiler will report a SyntaxError if "from ... import *" occurs
1062 in a function or class scope. The language reference has documented
1063 that this case is illegal, but the compiler never checked for it.
1064 The recent introduction of nested scope makes the meaning of this
1065 form of name binding ambiguous. In a future release, the compiler
1066 may allow this form when there is no possibility of ambiguity.
1067
Tim Peters40ead762001-01-27 05:35:26 +00001068- repr(string) is easier to read, now using hex escapes instead of octal,
1069 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1070
1071 >>> "\texample \r\n" + chr(0) + chr(255)
1072 '\texample \r\n\x00\xff' # in 2.1
1073 '\011example \015\012\000\377' # in 2.0
1074
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001075- Functions are now compared and hashed by identity, not by value, since
1076 the func_code attribute is writable.
1077
Fred Drakefb9d7122001-02-01 20:00:40 +00001078- Weak references (PEP 205) have been added. This involves a few
1079 changes in the core, an extension module (_weakref), and a Python
1080 module (weakref). The weakref module is the public interface. It
1081 includes support for "explicit" weak references, proxy objects, and
1082 mappings with weakly held values.
1083
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001084- A 'continue' statement can now appear in a try block within the body
1085 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001086 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001087
Tim Petersd7b5e882001-01-25 03:36:26 +00001088Standard library
1089
Barry Warsaw30dbd142001-01-31 22:14:01 +00001090- mailbox.py now has a new class, PortableUnixMailbox which is
1091 identical to UnixMailbox but uses a more portable scheme for
1092 determining From_ separators. Also, the constructors for all the
1093 classes in this module have a new optional `factory' argument, which
1094 is a callable used when new message classes must be instantiated by
1095 the next() method.
1096
Tim Petersd7b5e882001-01-25 03:36:26 +00001097- random.py is now self-contained, and offers all the functionality of
1098 the now-deprecated whrandom.py. See the docs for details. random.py
1099 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001100 and restoring the internal state of the generator; and jumpahead(n),
1101 for quickly forcing the internal state to be the same as if n calls to
1102 random() had been made. The latter is particularly useful for multi-
1103 threaded programs, creating one instance of the random.Random() class for
1104 each thread, then using .jumpahead() to force each instance to use a
1105 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001106
Tim Peters0de88fc2001-02-01 04:59:18 +00001107- random.py's seed() function is new. For bit-for-bit compatibility with
1108 prior releases, use the whseed function instead. The new seed function
1109 addresses two problems: (1) The old function couldn't produce more than
1110 about 2**24 distinct internal states; the new one about 2**45 (the best
1111 that can be done in the Wichmann-Hill generator). (2) The old function
1112 sometimes produced identical internal states when passed distinct
1113 integers, and there was no simple way to predict when that would happen;
1114 the new one guarantees to produce distinct internal states for all
1115 arguments in [0, 27814431486576L).
1116
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001117- The socket module now supports raw packets on Linux. The socket
1118 family is AF_PACKET.
1119
Tim Peters9ea17ac2001-02-02 05:57:15 +00001120- test_capi.py is a start at running tests of the Python C API. The tests
1121 are implemented by the new Modules/_testmodule.c.
1122
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001123- A new extension module, _symtable, provides provisional access to the
1124 internal symbol table used by the Python compiler. A higher-level
1125 interface will be added on top of _symtable in a future release.
1126
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001127- Removed the obsolete soundex module.
1128
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001129- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1130 the isSameNode method; NamedNodeMap the get method.
1131
1132- xml.sax.expatreader supports the lexical handler property; it
1133 generates comment, startCDATA, and endCDATA events.
1134
Tim Petersee826f82001-01-31 19:39:44 +00001135Windows changes
1136
1137- Build procedure: the zlib project is built in a different way that
1138 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001139 the zlib binary used. See PCbuild\readme.txt for details. Your old
1140 zlib-related directories can be deleted; you'll need to download fresh
1141 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001142
Tim Peters9ea17ac2001-02-02 05:57:15 +00001143- Build: New subproject _test for the benefit of test_capi.py (see above).
1144
Tim Petersb16c56f2001-02-02 21:24:51 +00001145- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1146 interface to some Python compiler internals).
1147
1148- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001149 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001150
Tim Petersa3a3a032000-11-30 05:22:44 +00001151What's New in Python 2.1 alpha 1?
1152=================================
1153
1154Core language, builtins, and interpreter
1155
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001156- There is a new Unicode companion to the PyObject_Str() API
1157 called PyObject_Unicode(). It behaves in the same way as the
1158 former, but assures that the returned value is an Unicode object
1159 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001160
Guido van Rossumf98eda02001-01-17 15:54:45 +00001161- The comparison operators support "rich comparison overloading" (PEP
1162 207). C extension types can provide a rich comparison function in
1163 the new tp_richcompare slot in the type object. The cmp() function
1164 and the C function PyObject_Compare() first try the new rich
1165 comparison operators before trying the old 3-way comparison. There
1166 is also a new C API PyObject_RichCompare() (which also falls back on
1167 the old 3-way comparison, but does not constrain the outcome of the
1168 rich comparison to a Boolean result).
1169
1170 The rich comparison function takes two objects (at least one of
1171 which is guaranteed to have the type that provided the function) and
1172 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1173 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1174 object, which may be NotImplemented (in which case the tp_compare
1175 slot function is used as a fallback, if defined).
1176
1177 Classes can overload individual comparison operators by defining one
1178 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001179 __ge__. There are no explicit "reflected argument" versions of
1180 these; instead, __lt__ and __gt__ are each other's reflection,
1181 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1182 reflection (similar at the C level). No other implications are
1183 made; in particular, Python does not assume that == is the Boolean
1184 inverse of !=, or that < is the Boolean inverse of >=. This makes
1185 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001186
1187 Classes or types that want to implement (in)equality tests but not
1188 the ordering operators (i.e. unordered types) should implement ==
1189 and !=, and raise an error for the ordering operators.
1190
Guido van Rossuma88479f2001-01-18 14:28:08 +00001191 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001192 Boolean; e.g. a matrix type might want to return a matrix of bits
1193 for A < B, giving elementwise comparisons. Such types should ensure
1194 that any interpretation of their value in a Boolean context raises
1195 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1196 at the C level) to always raise an exception.
1197
Guido van Rossuma88479f2001-01-18 14:28:08 +00001198- Complex numbers use rich comparisons to define == and != but raise
1199 an exception for <, <=, > and >=. Unfortunately, this also means
1200 that cmp() of two complex numbers raises an exception when the two
1201 numbers differ. Since it is not mathematically meaningful to compare
1202 complex numbers except for equality, I hope that this doesn't break
1203 too much code.
1204
Tim Peters3389f192001-02-18 08:48:49 +00001205- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001206 not defined by the language, other than that it's arbitrary but
1207 consistent (see the Reference Manual). An implementation detail changed
1208 in 2.1a1 such that None now compares less than any other object. Code
1209 relying on this new behavior (like code that relied on the previous
1210 behavior) does so at its own risk.
1211
Barry Warsaw573b5412001-01-15 20:43:18 +00001212- Functions and methods now support getting and setting arbitrarily
1213 named attributes (PEP 232). Functions have a new __dict__
1214 (a.k.a. func_dict) which hold the function attributes. Methods get
1215 and set attributes on their underlying im_func. It is a TypeError
1216 to set an attribute on a bound method.
1217
Guido van Rossum051e3352001-01-15 19:11:10 +00001218- The xrange() object implementation has been improved so that
1219 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1220 limitation that in this case len(xrange(sys.maxint)) can't be
1221 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1222 work fine as long as the index i doesn't actually reach 2**31.
1223 (Python uses regular ints for sequence and string indices; fixing
1224 that is much more work.)
1225
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001226- Two changes to from...import:
1227
Guido van Rossumba381232001-02-03 15:06:40 +00001228 1) "from M import X" now works even if (after loading module M)
1229 sys.modules['M'] is not a real module; it's basically a getattr()
1230 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001231
1232 2) "from M import *" now looks for M.__all__ to decide which names to
1233 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1234 filters out names starting with '_' as before. Whether or not
1235 __all__ exists, there's no restriction on the type of M.
1236
Guido van Rossumf61f1662001-01-10 20:13:55 +00001237- File objects have a new method, xreadlines(). This is the fastest
1238 way to iterate over all lines in a file:
1239
1240 for line in file.xreadlines():
1241 ...do something to line...
1242
1243 See the xreadlines module (mentioned below) for how to do this for
1244 other file-like objects.
1245
1246- Even if you don't use file.xreadlines(), you may expect a speedup on
1247 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001248 quite a bit in platform-specific ways: on systems (like Linux) that
1249 support flockfile(), getc_unlocked(), and funlockfile(), those are
1250 used by default. On systems (like Windows) without getc_unlocked(),
1251 a complicated (but still thread-safe) method using fgets() is used by
1252 default.
1253
Tim Petersd52269b2001-01-25 06:23:18 +00001254 You can force use of the fgets() method by #define'ing
1255 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001256 getc_unlocked()).
1257
Tim Petersd52269b2001-01-25 06:23:18 +00001258 You can force fgets() not to be used by #define'ing
1259 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001260 test_bufio.py fails -- and let us know if it does!).
1261
1262- In addition, the fileinput module, while still slower than the other
1263 methods on most platforms, has been sped up too, by using
1264 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001265
1266- Support for run-time warnings has been added, including a new
1267 command line option (-W) to specify the disposition of warnings.
1268 See the description of the warnings module below.
1269
1270- Extensive changes have been made to the coercion code. This mostly
1271 affects extension modules (which can now implement mixed-type
1272 numerical operators without having to use coercion), but
1273 occasionally, in boundary cases the coercion semantics have changed
1274 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001275 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001276 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001277 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001278
Guido van Rossumf98eda02001-01-17 15:54:45 +00001279- In connection with the coercion changes, a new built-in singleton
1280 object, NotImplemented is defined. This can be returned for
1281 operations that wish to indicate they are not implemented for a
1282 particular combination of arguments. From C, this is
1283 Py_NotImplemented.
1284
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001285- The interpreter accepts now bytecode files on the command line even
1286 if they do not have a .pyc or .pyo extension. On Linux, after executing
1287
Martin v. Löwise214baa2001-02-04 22:37:56 +00001288import imp,sys,string
1289magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1290reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1291open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001292
1293 any byte code file can be used as an executable (i.e. as an argument
1294 to execve(2)).
1295
Tim Peters9940b802000-12-01 07:59:35 +00001296- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001297 character. In 1.6 and earlier, they never produced a sign,
1298 and raised an error if the value of the long was too large
1299 to fit in a Python int. In 2.0, they produced a sign if and
1300 only if too large to fit in an int. This was inconsistent
1301 across platforms (because the size of an int varies across
1302 platforms), and inconsistent with hex() and oct(). Example:
1303
1304 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001305 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001306 'ffffffbe' # in 2.0 and before, on 32-bit machines
1307 >>> hex(-0x42L)
1308 '-0x42L' # in all versions of Python
1309
Tim Peters9940b802000-12-01 07:59:35 +00001310 The behavior of %d formats for negative Python longs remains
1311 the same as in 2.0 (although in 1.6 and before, they raised
1312 an error if the long didn't fit in a Python int).
1313
1314 %u formats don't make sense for Python longs, but are allowed
1315 and treated the same as %d in 2.1. In 2.0, a negative long
1316 formatted via %u produced a sign if and only if too large to
1317 fit in an int. In 1.6 and earlier, a negative long formatted
1318 via %u raised an error if it was too big to fit in an int.
1319
Guido van Rossum3661d392000-12-12 22:10:31 +00001320- Dictionary objects have an odd new method, popitem(). This removes
1321 an arbitrary item from the dictionary and returns it (in the form of
1322 a (key, value) pair). This can be useful for algorithms that use a
1323 dictionary as a bag of "to do" items and repeatedly need to pick one
1324 item. Such algorithms normally end up running in quadratic time;
1325 using popitem() they can usually be made to run in linear time.
1326
Tim Peters36cdad12000-12-29 02:06:45 +00001327Standard library
1328
Thomas Woutersfe385252001-01-19 23:16:56 +00001329- In the time module, the time argument to the functions strftime,
1330 localtime, gmtime, asctime and ctime is now optional, defaulting to
1331 the current time (in the local timezone).
1332
Guido van Rossumda91f222001-01-15 16:36:08 +00001333- The ftplib module now defaults to passive mode, which is deemed a
1334 more useful default given that clients are often inside firewalls
1335 these days. Note that this could break if ftplib is used to connect
1336 to a *server* that is inside a firewall, from outside; this is
1337 expected to be a very rare situation. To fix that, you can call
1338 ftp.set_pasv(0).
1339
Martin v. Löwis10a27872001-01-13 09:54:41 +00001340- The module site now treats .pth files not only for path configuration,
1341 but also supports extensions to the initialization code: Lines starting
1342 with import are executed.
1343
Guido van Rossumf61f1662001-01-10 20:13:55 +00001344- There's a new module, warnings, which implements a mechanism for
1345 issuing and filtering warnings. There are some new built-in
1346 exceptions that serve as warning categories, and a new command line
1347 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1348 turns warnings into errors). warnings.warn(message[, category])
1349 issues a warning message; this can also be called from C as
1350 PyErr_Warn(category, message).
1351
1352- A new module xreadlines was added. This exports a single factory
1353 function, xreadlines(). The intention is that this code is the
1354 absolutely fastest way to iterate over all lines in an open
1355 file(-like) object:
1356
1357 import xreadlines
1358 for line in xreadlines.xreadlines(file):
1359 ...do something to line...
1360
1361 This is equivalent to the previous the speed record holder using
1362 file.readlines(sizehint). Note that if file is a real file object
1363 (as opposed to a file-like object), this is equivalent:
1364
1365 for line in file.xreadlines():
1366 ...do something to line...
1367
Tim Peters36cdad12000-12-29 02:06:45 +00001368- The bisect module has new functions bisect_left, insort_left,
1369 bisect_right and insort_right. The old names bisect and insort
1370 are now aliases for bisect_right and insort_right. XXX_right
1371 and XXX_left methods differ in what happens when the new element
1372 compares equal to one or more elements already in the list: the
1373 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001374 right. Code that doesn't care where equal elements end up should
1375 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001376
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001377- The new curses.panel module wraps the panel library that forms part
1378 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1379
Guido van Rossumf61f1662001-01-10 20:13:55 +00001380- The SocketServer module now sets the allow_reuse_address flag by
1381 default in the TCPServer class.
1382
1383- A new function, sys._getframe(), returns the stack frame pointer of
1384 the caller. This is intended only as a building block for
1385 higher-level mechanisms such as string interpolation.
1386
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001387- The pyexpat module supports a number of new handlers, which are
1388 available only in expat 1.2. If invocation of a callback fails, it
1389 will report an additional frame in the traceback. Parser objects
1390 participate now in garbage collection. If expat reports an unknown
1391 encoding, pyexpat will try to use a Python codec; that works only
1392 for single-byte charsets. The parser type objects is exposed as
1393 XMLParserObject.
1394
1395- xml.dom now offers standard definitions for symbolic node type and
1396 exception code constants, and a hierarchy of DOM exceptions. minidom
1397 was adjusted to use them.
1398
1399- The conformance of xml.dom.minidom to the DOM specification was
1400 improved. It detects a number of additional error cases; the
1401 previous/next relationship works even when the tree is modified;
1402 Node supports the normalize() method; NamedNodeMap, DocumentType and
1403 DOMImplementation classes were added; Element supports the
1404 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1405 method.
1406
Guido van Rossumf61f1662001-01-10 20:13:55 +00001407Build issues
1408
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001409- For Unix (and Unix-compatible) builds, configuration and building of
1410 extension modules is now greatly automated. Rather than having to
1411 edit the Modules/Setup file to indicate which modules should be
1412 built and where their include files and libraries are, a
1413 distutils-based setup.py script now takes care of building most
1414 extension modules. All extension modules built this way are built
1415 as shared libraries. Only a few modules that must be linked
1416 statically are still listed in the Setup file; you won't need to
1417 edit their configuration.
1418
1419- Python should now build out of the box on Cygwin. If it doesn't,
1420 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001421
1422- Python now always uses its own (renamed) implementation of getopt()
1423 -- there's too much variation among C library getopt()
1424 implementations.
1425
1426- C++ compilers are better supported; the CXX macro is always set to a
1427 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001428
Tim Petersd92dfe02000-12-12 01:18:41 +00001429Windows changes
1430
1431- select module: By default under Windows, a select() call
1432 can specify no more than 64 sockets. Python now boosts
1433 this Microsoft default to 512. If you need even more than
1434 that, see the MS docs (you'll need to #define FD_SETSIZE
1435 and recompile Python from source).
1436
Guido van Rossumf61f1662001-01-10 20:13:55 +00001437- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1438 subdirectory is no more!
1439
Tim Petersa3a3a032000-11-30 05:22:44 +00001440
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001441What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001442=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001443
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001444Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001445changes are in the file HISTORY. If you are making the jump directly
1446from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1447HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001448
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001449Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1450the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1451http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001452
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001453--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001454
1455======================================================================
1456
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001457What's new in 2.0 (since release candidate 1)?
1458==============================================
1459
1460Standard library
1461
1462- The copy_reg module was modified to clarify its intended use: to
1463 register pickle support for extension types, not for classes.
1464 pickle() will raise a TypeError if it is passed a class.
1465
1466- Fixed a bug in gettext's "normalize and expand" code that prevented
1467 it from finding an existing .mo file.
1468
1469- Restored support for HTTP/0.9 servers in httplib.
1470
Tim Peters989b7b92000-10-16 20:24:53 +00001471- The math module was changed to stop raising OverflowError in case of
1472 underflow, and return 0 instead in underflow cases. Whether Python
1473 used to raise OverflowError in case of underflow was platform-
1474 dependent (it did when the platform math library set errno to ERANGE
1475 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001476
1477- Fixed a bug in StringIO that occurred when the file position was not
1478 at the end of the file and write() was called with enough data to
1479 extend past the end of the file.
1480
1481- Fixed a bug that caused Tkinter error messages to get lost on
1482 Windows. The bug was fixed by replacing direct use of
1483 interp->result with Tcl_GetStringResult(interp).
1484
1485- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1486 redirect response.
1487
1488- Several changes were made to distutils: Some debugging code was
1489 removed from util. Fixed the installer used when an external zip
1490 program (like WinZip) is not found; the source code for this
1491 installer is in Misc/distutils. check_lib() was modified to behave
1492 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1493 test for whether installed modules are on sys.path was changed to
1494 use both normcase() and normpath().
1495
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001496- Several minor bugs were fixed in the xml package (the minidom,
1497 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001498
1499- The regression test driver (regrtest.py) behavior when invoked with
1500 -l changed: It now reports a count of objects that are recognized as
1501 garbage but not freed by the garbage collector.
1502
Tim Peters989b7b92000-10-16 20:24:53 +00001503- The regression test for the math module was changed to test
1504 exceptional behavior when the test is run in verbose mode. Python
1505 cannot yet guarantee consistent exception behavior across platforms,
1506 so the exception part of test_math is run only in verbose mode, and
1507 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001508
1509Internals
1510
1511- PyOS_CheckStack() has been disabled on Win64, where it caused
1512 test_sre to fail.
1513
1514Build issues
1515
1516- Changed compiler flags, so that gcc is always invoked with -Wall and
1517 -Wstrict-prototypes. Users compiling Python with GCC should see
1518 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001519 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001520 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001521
Tim Petersa3a3a032000-11-30 05:22:44 +00001522- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001523
1524Tools and other miscellany
1525
1526- The compiler in Tools/compiler was updated to support the new
1527 language features introduced in 2.0: extended print statement, list
1528 comprehensions, and augmented assignments. The new compiler should
1529 also be backwards compatible with Python 1.5.2; the compiler will
1530 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001531 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001532
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001533What's new in 2.0 release candidate 1 (since beta 2)?
1534=====================================================
1535
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001536What is release candidate 1?
1537
1538We believe that release candidate 1 will fix all known bugs that we
1539intend to fix for the 2.0 final release. This release should be a bit
1540more stable than the previous betas. We would like to see even more
1541widespread testing before the final release, so we are producing this
1542release candidate. The final release will be exactly the same unless
1543any show-stopping (or brown bag) bugs are found by testers of the
1544release candidate.
1545
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001546All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001547to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001548
1549Core language, builtins, and interpreter
1550
1551- A bug that caused crashes when __coerce__ was used with augmented
1552 assignment, e.g. +=, was fixed.
1553
1554- Raise ZeroDivisionError when raising zero to a negative number,
1555 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1556 power operator and the result of math.pow(0.0, -2.0) will vary by
1557 platform. On Linux, it raises a ValueError.
1558
1559- A bug in Unicode string interpolation was fixed that occasionally
1560 caused errors with formats including "%%". For example, the
1561 following expression "%% %s" % u"abc" no longer raises a TypeError.
1562
1563- Compilation of deeply nested expressions raises MemoryError instead
1564 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1565
1566- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1567 rendering them useless. They are now written in binary mode again.
1568
1569Standard library
1570
1571- Keyword arguments are now accepted for most pattern and match object
1572 methods in SRE, the standard regular expression engine.
1573
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001574- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001575 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001576
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001577- Several bugs in the Unicode handling and error handling in _tkinter
1578 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001579
1580- Fix memory management errors in Merge() and Tkapp_Call() routines.
1581
1582- Several changes were made to cStringIO to make it compatible with
1583 the file-like object interface and with StringIO. If operations are
1584 performed on a closed object, an exception is raised. The truncate
1585 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001586 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001587
1588- There were many changes made to the linuxaudiodev module and its
1589 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001590 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001591
1592 Note that this module is named poorly, because it should work
1593 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001594 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001595
1596 The module now raises exceptions when errors occur instead of
1597 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1598 audio) and defines a getptr() method that calls the
1599 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1600
1601- The library_version attribute, introduced in an earlier beta, was
1602 removed because it can not be supported with early versions of the C
1603 readline library, which provides no way to determine the version at
1604 compile-time.
1605
1606- The binascii module is now enabled on Win64.
1607
Tim Peters46446d62000-10-09 21:19:31 +00001608- tokenize.py no longer suffers "recursion depth" errors when parsing
1609 programs with very long string literals.
1610
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001611Internals
1612
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001613- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001614 which is called when the interpreter starts up to determine where
1615 the standard library is installed. These vulnerabilities affect all
1616 previous versions of Python and can be exploited by setting very
1617 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1618 setuid Python script, although use of the wrapper in
1619 Misc/setuid-prog.c will eliminate the vulnerability.
1620
1621- Fixed garbage collection bugs in instance creation that were
1622 triggered when errors occurred during initialization. The solution,
1623 applied in cPickle and in PyInstance_New(), is to call
1624 PyObject_GC_Init() after the initialization of the object's
1625 container attributes is complete.
1626
1627- pyexpat adds definitions of PyModule_AddStringConstant and
1628 PyModule_AddObject if the Python version is less than 2.0, which
1629 provides compatibility with PyXML on Python 1.5.2.
1630
1631- If the platform has a bogus definition for LONG_BIT (the number of
1632 bits in a long), an error will be reported at compile time.
1633
1634- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1635 collection crashes and possibly other, unreported crashes.
1636
1637- Fixed a memory leak in _PyUnicode_Fini().
1638
1639Build issues
1640
1641- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001642 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001643 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001644
1645- The mmap.PAGESIZE constant is now initialized using sysconf when
1646 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1647
1648- The md5 file should now compile on all platforms.
1649
1650- The select module now compiles on platforms that do not define
1651 POLLRDNORM and related constants.
1652
1653- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001654 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001655
Jeremy Hylton10921202000-10-09 18:34:12 +00001656- BeOS: A number of changes were made to the build and installation
1657 process. ar-fake now operates on a directory of object files.
1658 dl_export.h is gone, and its macros now appear on the mwcc command
1659 line during build on PPC BeOS.
1660
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001661- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001662 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001663
1664- Cygwin: Support for shared libraries, Tkinter, and sockets.
1665
1666- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1667
1668Tools and other miscellany
1669
1670- Removed debugging prints from main used with freeze.
1671
Tim Peters46446d62000-10-09 21:19:31 +00001672- IDLE auto-indent no longer crashes when it encounters Unicode
1673 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001674
1675What's new in 2.0 beta 2 (since beta 1)?
1676========================================
1677
1678Core language, builtins, and interpreter
1679
Tim Peters482c0212000-09-26 06:33:09 +00001680- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001681 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001682
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001683- Add -h and -V command line options to print the usage message and
1684 Python version number and exit immediately.
1685
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001686- eval() and exec accept Unicode objects as code parameters.
1687
1688- getattr() and setattr() now also accept Unicode objects for the
1689 attribute name, which are converted to strings using the default
1690 encoding before lookup.
1691
1692- Multiplication on string and Unicode now does proper bounds
1693 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1694 string is too long."
1695
1696- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001697 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001698
Jeremy Hylton1b618592000-09-26 05:32:36 +00001699
1700Standard library and extensions
1701
Guido van Rossum5b08f132001-04-16 02:05:23 +00001702- socket module: the OpenSSL code now adds support for RAND_status()
1703 and EGD (Entropy Gathering Device).
1704
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001705- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001706 argument checking; it still takes no arguments.
1707
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001708- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001709
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001710- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001711
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001712- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001713
1714- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001715 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001716
1717- copy: Copy Unicode objects atomically.
1718
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001719- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001720
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001721- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001722
Fred Drake67233bc2000-09-26 16:40:27 +00001723- dbm: Add get() and setdefault() methods to dbm object. Add constant
1724 `library' to module that names the library used. Added doc strings
1725 and method names to error messages. Uses configure to determine
1726 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1727 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001728
1729- distutils: Update to version 0.9.3.
1730
1731- dl: Add several dl.RTLD_ constants.
1732
1733- fpectl: Now supported on FreeBSD.
1734
1735- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1736 found by the collector will be saved in gc.garbage. This is useful
1737 for debugging a program that creates reference cycles.
1738
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001739- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001740 of HTTP class. Do not close socket on zero-length response. Do not
1741 crash when server sends invalid content-length header.
1742
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001743- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001744
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001745- marshal: When reading a short, sign-extend on platforms where shorts
1746 are bigger than 16 bits. When reading a long, repair the unportable
1747 sign extension that was being done for 64-bit machines. (It assumed
1748 that signed right shift sign-extends.)
1749
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001750- operator: Add contains(), invert(), __invert__() as aliases for
1751 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001752
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001753- os: Add support for popen2() and popen3() on all platforms where
1754 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001755
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001756- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001757 clicking on a file in Explorer (or passing the file name to the
1758 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001759
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001760- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001761 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001762
1763- pickle: Now raises ValueError when an invalid pickle that contains
1764 a non-string repr where a string repr was expected. This behavior
1765 matches cPickle.
1766
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001767- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001768
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001769- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001770
1771- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001772 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001773 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001774
1775- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001776 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001777
1778- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001779 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001780 few cycles during startup since the first call to
1781 setdefaultencoding() will initialize the codec registry and the
1782 encodings package.
1783
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001784- socket: Support for size hint in readlines() method of object returned
1785 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001786
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001787- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001788 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001789 is followed by whitespace.
1790
Tim Petersa3a3a032000-11-30 05:22:44 +00001791- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001792
1793- struct: Check ranges for bytes and shorts.
1794
1795- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001796 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001797
1798- Tkinter: Image objects are now guaranteed to have unique ids. Set
1799 event.delta to zero if Tk version doesn't support mousewheel.
1800 Removed some debugging prints.
1801
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001802- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001803
Fred Drake67233bc2000-09-26 16:40:27 +00001804- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001805 which works around a bug in Norton AntiVirus 2000 that leads directly
1806 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001807
1808- xml: New version detection code allows PyXML to override standard
1809 XML package if PyXML version is greater than 0.6.1.
1810
Fred Drake64bb3802000-09-26 16:21:35 +00001811- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1812 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1813 tree only for nodes which are sufficiently interesting to a specific
1814 application. Does not provide the HTML-specific extensions. Still
1815 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001816
Fred Drake64bb3802000-09-26 16:21:35 +00001817- xml.sax: SAX 2 support for Python, including all the handler
1818 interfaces needed to process XML 1.0 compliant XML. Some
1819 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001820
Fred Drake64bb3802000-09-26 16:21:35 +00001821- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1822 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001823
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001824
Jeremy Hylton1b618592000-09-26 05:32:36 +00001825C API
1826
1827- Add three new convenience functions for module initialization --
1828 PyModule_AddObject(), PyModule_AddIntConstant(), and
1829 PyModule_AddStringConstant().
1830
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001831- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001832 removed and add #error to Python.h if NULL isn't defined after
1833 #include of stdio.h.
1834
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001835- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001836 backwards compatibility (at the source level) with old extensions.
1837
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001838- A wrapper API was added for signal() and sigaction(). Instead of
1839 either function, always use PyOS_getsig() to get a signal handler
1840 and PyOS_setsig() to set one. A new convenience typedef
1841 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001842
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001843- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001844 internal data buffer and size of a string object -- or the default
1845 encoded version of a Unicode object.
1846
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001847- PyString_Size() and PyString_AsString() accept Unicode objects.
1848
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001849- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001850 exists). INT_MAX and LONG_MAX will always be defined, even if
1851 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001852
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001853- PyFloat_FromString takes a second argument, pend, that was
1854 effectively useless. It is now officially useless but preserved for
1855 backwards compatibility. If the pend argument is not NULL, *pend is
1856 set to NULL.
1857
1858- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1859 for the attribute name. See note on getattr() above.
1860
1861- A few bug fixes to argument processing for Unicode.
1862 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1863 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1864 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001865 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001866
1867- Py_BuildValue accepts B format (for bgen-generated code).
1868
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001869
Jeremy Hylton1b618592000-09-26 05:32:36 +00001870Internals
1871
1872- On Unix, fix code for finding Python installation directory so that
1873 it works when argv[0] is a relative path.
1874
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001875- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001876 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001877 rather than by generating a copy of the object.
1878
Tim Peters482c0212000-09-26 06:33:09 +00001879- Several of the internal Unicode tables are much smaller now, and
1880 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001881
Jeremy Hylton97693b02000-09-26 17:42:51 +00001882- In the garbage collector: Fixed bug in collection of tuples. Fixed
1883 bug that caused some instances to be removed from the container set
1884 while they were still live. Fixed parsing in gc.set_debug() for
1885 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001886
1887- Fixed refcount problem in instance deallocation that only occurred
1888 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1889
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001890- On Windows, getpythonregpath is now protected against null data in
1891 registry key.
1892
1893- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001894 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001895
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001896
Jeremy Hylton1b618592000-09-26 05:32:36 +00001897Build and platform-specific issues
1898
1899- Better support of GNU Pth via --with-pth configure option.
1900
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001901- Python/C API now properly exposed to dynamically-loaded extension
1902 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001903
1904- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1905 Don't define MS_SYNC to be zero when it is undefined. Added missing
1906 prototypes in posixmodule.c.
1907
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001908- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001909 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001910
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001911- Fix largefile support on older NetBSD systems and OpenBSD by adding
1912 define for TELL64.
1913
1914
1915Tools and other miscellany
1916
1917- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1918
1919- freeze: The modulefinder now works with 2.0 opcodes.
1920
Tim Petersa3a3a032000-11-30 05:22:44 +00001921- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001922 Move hackery of sys.argv until after the Tk instance has been
1923 created, which allows the application-specific Tkinter
1924 initialization to be executed if present; also pass an explicit
1925 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001926
Jeremy Hylton1b618592000-09-26 05:32:36 +00001927
1928What's new in 2.0 beta 1?
1929=========================
1930
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001931Source Incompatibilities
1932------------------------
1933
1934None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1935such as single-argument append(), connect() and bind(), and changes to
1936str(long) and repr(float).
1937
1938
1939Binary Incompatibilities
1940------------------------
1941
1942- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1943with Python 2.0; these extensions will have to be rebuilt for Python
19442.0.
1945
1946- On Windows, attempting to import a third party extension built for
1947Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1948can do about this. Check your PYTHONPATH environment variable!
1949
1950- Python bytecode files (*.pyc and *.pyo) are not compatible between
1951releases.
1952
1953
1954Overview of Changes Since 1.6
1955-----------------------------
1956
1957There are many new modules (including brand new XML support through
1958the xml package, and i18n support through the gettext module); a list
1959of all new modules is included below. Lots of bugs have been fixed.
1960
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001961The process for making major new changes to the language has changed
1962since Python 1.6. Enhancements must now be documented by a Python
1963Enhancement Proposal (PEP) before they can be accepted.
1964
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001965There are several important syntax enhancements, described in more
1966detail below:
1967
1968 - Augmented assignment, e.g. x += 1
1969
1970 - List comprehensions, e.g. [x**2 for x in range(10)]
1971
1972 - Extended import statement, e.g. import Module as Name
1973
1974 - Extended print statement, e.g. print >> file, "Hello"
1975
1976Other important changes:
1977
1978 - Optional collection of cyclical garbage
1979
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001980Python Enhancement Proposal (PEP)
1981---------------------------------
1982
1983PEP stands for Python Enhancement Proposal. A PEP is a design
1984document providing information to the Python community, or describing
1985a new feature for Python. The PEP should provide a concise technical
1986specification of the feature and a rationale for the feature.
1987
1988We intend PEPs to be the primary mechanisms for proposing new
1989features, for collecting community input on an issue, and for
1990documenting the design decisions that have gone into Python. The PEP
1991author is responsible for building consensus within the community and
1992documenting dissenting opinions.
1993
1994The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001995
1996Augmented Assignment
1997--------------------
1998
1999This must have been the most-requested feature of the past years!
2000Eleven new assignment operators were added:
2001
Guido van Rossume905e952000-09-05 12:42:46 +00002002 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002003
2004For example,
2005
2006 A += B
2007
2008is similar to
2009
2010 A = A + B
2011
2012except that A is evaluated only once (relevant when A is something
2013like dict[index].attr).
2014
2015However, if A is a mutable object, A may be modified in place. Thus,
2016if A is a number or a string, A += B has the same effect as A = A+B
2017(except A is only evaluated once); but if a is a list, A += B has the
2018same effect as A.extend(B)!
2019
2020Classes and built-in object types can override the new operators in
2021order to implement the in-place behavior; the not-in-place behavior is
2022used automatically as a fallback when an object doesn't implement the
2023in-place behavior. For classes, the method name is derived from the
2024method name for the corresponding not-in-place operator by inserting
2025an 'i' in front of the name, e.g. __iadd__ implements in-place
2026__add__.
2027
2028Augmented assignment was implemented by Thomas Wouters.
2029
2030
2031List Comprehensions
2032-------------------
2033
2034This is a flexible new notation for lists whose elements are computed
2035from another list (or lists). The simplest form is:
2036
2037 [<expression> for <variable> in <sequence>]
2038
Guido van Rossum56db0952000-09-06 23:34:25 +00002039For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002040This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002041
2042You can also add a condition:
2043
2044 [<expression> for <variable> in <sequence> if <condition>]
2045
2046For example, [w for w in words if w == w.lower()] would yield the list
2047of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002048than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002049
2050You can also have nested for loops and more than one 'if' clause. For
2051example, here's a function that flattens a sequence of sequences::
2052
2053 def flatten(seq):
2054 return [x for subseq in seq for x in subseq]
2055
2056 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2057
2058This prints
2059
2060 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2061
2062List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002063Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002064
2065
2066Extended Import Statement
2067-------------------------
2068
2069Many people have asked for a way to import a module under a different
2070name. This can be accomplished like this:
2071
2072 import foo
2073 bar = foo
2074 del foo
2075
2076but this common idiom gets old quickly. A simple extension of the
2077import statement now allows this to be written as follows:
2078
2079 import foo as bar
2080
2081There's also a variant for 'from ... import':
2082
2083 from foo import bar as spam
2084
2085This also works with packages; e.g. you can write this:
2086
2087 import test.regrtest as regrtest
2088
2089Note that 'as' is not a new keyword -- it is recognized only in this
2090context (this is only possible because the syntax for the import
2091statement doesn't involve expressions).
2092
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002093Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002094
2095
2096Extended Print Statement
2097------------------------
2098
2099Easily the most controversial new feature, this extension to the print
2100statement adds an option to make the output go to a different file
2101than the default sys.stdout.
2102
2103For example, to write an error message to sys.stderr, you can now
2104write:
2105
2106 print >> sys.stderr, "Error: bad dog!"
2107
2108As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002109evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002110
2111 print >> None, "Hello world"
2112
2113is equivalent to
2114
2115 print "Hello world"
2116
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002117Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002118
2119
2120Optional Collection of Cyclical Garbage
2121---------------------------------------
2122
2123Python is now equipped with a garbage collector that can hunt down
2124cyclical references between Python objects. It's no replacement for
2125reference counting; in fact, it depends on the reference counts being
2126correct, and decides that a set of objects belong to a cycle if all
2127their reference counts can be accounted for from their references to
2128each other. This devious scheme was first proposed by Eric Tiedemann,
2129and brought to implementation by Neil Schemenauer.
2130
2131There's a module "gc" that lets you control some parameters of the
2132garbage collection. There's also an option to the configure script
2133that lets you enable or disable the garbage collection. In 2.0b1,
2134it's on by default, so that we (hopefully) can collect decent user
2135experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002136performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002137off by default in the final 2.0 release.
2138
2139
2140Smaller Changes
2141---------------
2142
2143A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2144map(None, seq1, seq2, ...) when the sequences have the same length;
2145i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2146the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002147zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002148
2149sys.version_info is a tuple (major, minor, micro, level, serial).
2150
2151Dictionaries have an odd new method, setdefault(key, default).
2152dict.setdefault(key, default) returns dict[key] if it exists; if not,
2153it sets dict[key] to default and returns that value. Thus:
2154
2155 dict.setdefault(key, []).append(item)
2156
2157does the same work as this common idiom:
2158
2159 if not dict.has_key(key):
2160 dict[key] = []
2161 dict[key].append(item)
2162
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002163There are two new variants of SyntaxError that are raised for
2164indentation-related errors: IndentationError and TabError.
2165
2166Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2167escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002168
2169The limits on the size of expressions and file in Python source code
2170have been raised from 2**16 to 2**32. Previous versions of Python
2171were limited because the maximum argument size the Python VM accepted
2172was 2**16. This limited the size of object constructor expressions,
2173e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2174limit was raised thanks to a patch by Charles Waldman that effectively
2175fixes the problem. It is now much more likely that you will be
2176limited by available memory than by an arbitrary limit in Python.
2177
2178The interpreter's maximum recursion depth can be modified by Python
2179programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2180limit is the maximum number of recursive calls that can be made by
2181Python code. The limit exists to prevent infinite recursion from
2182overflowing the C stack and causing a core dump. The default value is
21831000. The maximum safe value for a particular platform can be found
2184by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002185
2186New Modules and Packages
2187------------------------
2188
2189atexit - for registering functions to be called when Python exits.
2190
2191imputil - Greg Stein's alternative API for writing custom import
2192hooks.
2193
2194pyexpat - an interface to the Expat XML parser, contributed by Paul
2195Prescod.
2196
2197xml - a new package with XML support code organized (so far) in three
2198subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2199would fill a volume. There's a special feature whereby a
2200user-installed package named _xmlplus overrides the standard
2201xmlpackage; this is intended to give the XML SIG a hook to distribute
2202backwards-compatible updates to the standard xml package.
2203
2204webbrowser - a platform-independent API to launch a web browser.
2205
2206
Guido van Rossume905e952000-09-05 12:42:46 +00002207Changed Modules
2208---------------
2209
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002210array -- new methods for array objects: count, extend, index, pop, and
2211remove
2212
2213binascii -- new functions b2a_hex and a2b_hex that convert between
2214binary data and its hex representation
2215
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002216calendar -- Many new functions that support features including control
2217over which day of the week is the first day, returning strings instead
2218of printing them. Also new symbolic constants for days of week,
2219e.g. MONDAY, ..., SUNDAY.
2220
2221cgi -- FieldStorage objects have a getvalue method that works like a
2222dictionary's get method and returns the value attribute of the object.
2223
2224ConfigParser -- The parser object has new methods has_option,
2225remove_section, remove_option, set, and write. They allow the module
2226to be used for writing config files as well as reading them.
2227
2228ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002229optionally support the RFC 959 REST command.
2230
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002231gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002232
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002233httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2234the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002235
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002236locale -- implement getdefaultlocale for Win32 and Macintosh
2237
2238marshal -- no longer dumps core when marshaling deeply nested or
2239recursive data structures
2240
2241os -- new functions isatty, seteuid, setegid, setreuid, setregid
2242
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002243os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2244support under Unix.
2245
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002246os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002247
2248os.path -- fix semantics of os.path.commonprefix
2249
2250smtplib -- support for sending very long messages
2251
2252socket -- new function getfqdn()
2253
2254readline -- new functions to read, write and truncate history files.
2255The readline section of the library reference manual contains an
2256example.
2257
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002258select -- add interface to poll system call
2259
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002260shutil -- new copyfileobj function
2261
2262SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2263HTTP server.
2264
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002265Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002266
2267urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002268e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002269
2270whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002271
2272
2273Obsolete Modules
2274----------------
2275
2276None. However note that 1.6 made a whole slew of modules obsolete:
2277stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2278poly, zmod, strop, util, whatsound.
2279
2280
2281Changed, New, Obsolete Tools
2282----------------------------
2283
Tim Peters8b092332000-09-05 20:15:25 +00002284None.
Guido van Rossume905e952000-09-05 12:42:46 +00002285
2286
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002287C-level Changes
2288---------------
2289
2290Several cleanup jobs were carried out throughout the source code.
2291
2292All C code was converted to ANSI C; we got rid of all uses of the
2293Py_PROTO() macro, which makes the header files a lot more readable.
2294
2295Most of the portability hacks were moved to a new header file,
2296pyport.h; several other new header files were added and some old
2297header files were removed, in an attempt to create a more rational set
2298of header files. (Few of these ever need to be included explicitly;
2299they are all included by Python.h.)
2300
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002301Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002302and Win64, especially for the new Intel Itanium processor. Mick also
2303added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002304
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002305The C APIs to return an object's size have been update to consistently
2306use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2307previous versions, the abstract interfaces used PyXXX_Length and the
2308concrete interfaces used PyXXX_Size. The old names,
2309e.g. PyObject_Length, are still available for backwards compatibility
2310at the API level, but are deprecated.
2311
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002312The PyOS_CheckStack function has been implemented on Windows by
2313Fredrik Lundh. It prevents Python from failing with a stack overflow
2314on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002315
2316The GC changes resulted in creation of two new slots on object,
2317tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002318the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002319
2320The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002321C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002322
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002323PyErr_Format has been updated to automatically calculate the size of
2324the buffer needed to hold the formatted result string. This change
2325prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002326
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002327New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002328
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002329PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2330that are the same as their non-Ex counterparts except they take an
2331extra flag argument that tells them to close the file when done.
2332
2333XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002334
Tim Peters8b092332000-09-05 20:15:25 +00002335
2336Windows Changes
2337---------------
2338
2339New popen2/popen3/peopen4 in os module (see Changed Modules above).
2340
2341os.popen is much more usable on Windows 95 and 98. See Microsoft
2342Knowledge Base article Q150956. The Win9x workaround described there
2343is implemented by the new w9xpopen.exe helper in the root of your
2344Python installation. Note that Python uses this internally; it is not
2345a standalone program.
2346
2347Administrator privileges are no longer required to install Python
2348on Windows NT or Windows 2000. If you have administrator privileges,
2349Python's registry info will be written under HKEY_LOCAL_MACHINE.
2350Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002351under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002352uses of Python, but will prevent some advanced uses from working
2353(for example, running a Python script as an NT service, or possibly
2354from CGI).
2355
2356[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2357installer; instead, it installs the needed Tcl/Tk files directly in the
2358Python directory. If you already have a Tcl/Tk installation, this
2359wastes some disk space (about 4 Megs) but avoids problems with
2360conflicting Tcl/Tk installations, and makes it much easier for Python
2361to ensure that Tcl/Tk can find all its files.
2362
2363[This was new in 1.6] The Windows installer now installs by default in
2364\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2365
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002366
2367Updates to the changes between 1.5.2 and 1.6
2368--------------------------------------------
2369
2370The 1.6 NEWS file can't be changed after the release is done, so here
2371is some late-breaking news:
2372
2373New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2374and changes to getlocale() and setlocale().
2375
2376The new module is now enabled per default.
2377
2378It is not true that the encodings codecs cannot be used for normal
2379strings: the string.encode() (which is also present on 8-bit strings
2380!) allows using them for 8-bit strings too, e.g. to convert files from
2381cp1252 (Windows) to latin-1 or vice-versa.
2382
2383Japanese codecs are available from Tamito KAJIYAMA:
2384http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2385
2386
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002387======================================================================